* [RFA] i386/amd64 h/w watchpoints in gdbserver
@ 2009-04-30 7:19 Doug Evans
2009-05-01 8:10 ` Pierre Muller
2009-05-18 23:11 ` Doug Evans
0 siblings, 2 replies; 18+ messages in thread
From: Doug Evans @ 2009-04-30 7:19 UTC (permalink / raw)
To: gdb-patches, muller
Hi.
I took Pierre's patch here
http://sourceware.org/ml/gdb-patches/2009-02/msg00206.html
and added support for {i386,amd64}-linux.
Pierre, I _think_ I didn't break win32 support, but it is different
than what you originally wrote. Can you test it?
This patch assumes the gdbserver memory leak fix has been applied:
http://sourceware.org/ml/gdb-patches/2009-04/msg00803.html
2009-04-29 Pierre Muller <muller@ics.u-strasbg.fr>
Doug Evans <dje@google.com>
* Makefile.in (SFILES): Add i386-low.c
(i386_low_h): Define.
(i386-low.o): Add dependencies.
(linux-i386-low.o): Add i386-low.h dependency.
(linux-x86-64-low.o): Ditto.
(win32-i386-low.o): Ditto.
* i386-low.c: New file.
* i386-low.h: New file.
* configure.srv (i[34567]86-*-cygwin*): Add i386-low.o to srv_tgtobj.
(i[34567]86-*-linux*, i[34567]86-*-mingw*, x86_64-*-linux*): Ditto.
* linux-i386-low.c: Include stddef.h, i386-low.h.
(arch_process_info): New struct.
(i386_linux_dr_get, i386_linux_dr_set): New functions.
(i386_dr_low_set_addr, i386_dr_low_set_control): New functions.
(i386_dr_low_get_status): New function.
(i386_insert_watchpoint, i386_remove_watchpoint): New functions.
(i386_stopped_by_watchpoint, i386_stopped_data_address): New functions.
(i386_linux_new_process, i386_linux_new_thread): New functions.
(the_low_target): Add entries for insert_watchpoint, remove_watchpoint,
stopped_by_watchpoint, stopped_data_address, new_process, new_thread.
* linux-low.c (linux_add_process): Initialize arch_private.
(linux_remove_process): Free arch_private.
(notify_low_target_new_thread): New function.
(handle_extended_wait): Call it.
(linux_attach_lwp_1, linux_wait_1): Ditto.
(linux_insert_watchpoint): Update call to
the_low_target.insert_watchpoint.
(linux_remove_watchpoint): Update call to
the_low_target.remove_watchpoint.
(linux_stopped_by_watchpoint): Update call to
the_low_target.stopped_by_watchpoint.
(linux_stopped_data_address): Update call to
the_low_target.stopped_data_address.
* linux-low.h (process_info_private): New member arch_private.
(linux_target_ops): Add arch_private parameter to insert_watchpoint,
remove_watchpoint, stopped_by_watchpoint, stopped_data_address.
New members new_process, new_thread.
(ptid_of, PIDGET, TIDGET): New macros.
* linux-x86-64-low.c: Include stddef.h, i386-low.h.
(arch_process_info): New struct.
(x86_64_linux_dr_get, x86_64_linux_dr_set): New functions.
(i386_dr_low_set_addr, i386_dr_low_set_control): New functions.
(i386_dr_low_get_status): New function.
(x86_64_insert_watchpoint, x86_64_remove_watchpoint): New functions.
(x86_64_stopped_by_watchpoint): New function.
(x86_64_stopped_data_address): New function.
(x86_64_linux_new_process, x86_64_linux_new_thread): New functions.
(the_low_target): Add entries for insert_watchpoint, remove_watchpoint,
stopped_by_watchpoint, stopped_data_address, new_process, new_thread.
* server.h (paddr): Declare.
* utils.c (NUMCELLS, CELLSIZE): New macros.
(get_sell, xsnprintf, paddr): New functions.
* win32-arm-low.c (the_low_target): Add entries for insert_watchpoint,
remove_watchpoint, stopped_by_watchpoint, stopped_data_address.
* win32-i386-low.c: Include i386-low.h.
(i386_dr_low_set_addr, i386_dr_low_set_control): New functions.
(i386_dr_low_get_status): New function.
(the_low_target): Add entries for insert_watchpoint,
remove_watchpoint, stopped_by_watchpoint, stopped_data_address.
* win32-low.c (win32_insert_watchpoint): New function.
(win32_remove_watchpoint): New function.
(win32_stopped_by_watchpoint): New function.
(win32_stopped_data_address): New function.
(win32_target_ops): Add entries for insert_watchpoint,
remove_watchpoint, stopped_by_watchpoint, stopped_data_address.
* win32-low.h (win32_target_ops): New members insert_watchpoint,
remove_watchpoint, stopped_by_watchpoint, stopped_data_address.
Index: Makefile.in
===================================================================
RCS file: /cvs/src/src/gdb/gdbserver/Makefile.in,v
retrieving revision 1.73
diff -u -p -r1.73 Makefile.in
--- Makefile.in 1 Apr 2009 22:48:05 -0000 1.73
+++ Makefile.in 30 Apr 2009 01:23:29 -0000
@@ -104,7 +104,7 @@ SFILES= $(srcdir)/gdbreplay.c $(srcdir)/
$(srcdir)/thread-db.c $(srcdir)/utils.c \
$(srcdir)/linux-arm-low.c $(srcdir)/linux-cris-low.c \
$(srcdir)/linux-crisv32-low.c $(srcdir)/linux-i386-low.c \
- $(srcdir)/i387-fp.c \
+ ${srcdir}/i386-low.c $(srcdir)/i387-fp.c \
$(srcdir)/linux-ia64-low.c $(srcdir)/linux-low.c \
$(srcdir)/linux-m32r-low.c \
$(srcdir)/linux-m68k-low.c $(srcdir)/linux-mips-low.c \
@@ -287,6 +287,10 @@ signals.o: ../common/signals.c $(server_
memmem.o: ../gnulib/memmem.c
$(CC) -o memmem.o -c $(CPPFLAGS) $(INTERNAL_CFLAGS) $<
+i386_low_h = $(srcdir)/i386-low.h
+
+i386-low.o: i386-low.c $(i386_low_h) $(server_h) $(target_h)
+
i387-fp.o: i387-fp.c $(server_h)
linux-low.o: linux-low.c $(linux_low_h) $(server_h)
@@ -297,7 +301,7 @@ linux-arm-low.o: linux-arm-low.c $(linux
linux-cris-low.o: linux-cris-low.c $(linux_low_h) $(server_h)
linux-crisv32-low.o: linux-crisv32-low.c $(linux_low_h) $(server_h)
linux-i386-low.o: linux-i386-low.c $(linux_low_h) $(server_h) \
- $(gdb_proc_service_h)
+ $(gdb_proc_service_h) $(i386_low_h)
linux-ia64-low.o: linux-ia64-low.c $(linux_low_h) $(server_h)
linux-m32r-low.o: linux-m32r-low.c $(linux_low_h) $(server_h)
linux-mips-low.o: linux-mips-low.c $(linux_low_h) $(server_h) \
@@ -306,7 +310,7 @@ linux-ppc-low.o: linux-ppc-low.c $(linux
linux-s390-low.o: linux-s390-low.c $(linux_low_h) $(server_h)
linux-sh-low.o: linux-sh-low.c $(linux_low_h) $(server_h)
linux-x86-64-low.o: linux-x86-64-low.c $(linux_low_h) $(server_h) \
- $(gdb_proc_service_h)
+ $(gdb_proc_service_h) $(i386_low_h)
linux-xtensa-low.o: linux-xtensa-low.c xtensa-xtregs.c $(linux_low_h) $(server_h)
win32_low_h = $(srcdir)/win32-low.h
@@ -314,7 +318,7 @@ win32_low_h = $(srcdir)/win32-low.h
win32-low.o: win32-low.c $(win32_low_h) $(server_h) $(regdef_h) $(regcache_h)
win32-arm-low.o: win32-arm-low.c $(win32_low_h) $(server_h)
-win32-i386-low.o: win32-i386-low.c $(win32_low_h) $(server_h)
+win32-i386-low.o: win32-i386-low.c $(win32_low_h) $(server_h) $(i386_low_h)
spu-low.o: spu-low.c $(server_h)
Index: configure.srv
===================================================================
RCS file: /cvs/src/src/gdb/gdbserver/configure.srv,v
retrieving revision 1.40
diff -u -p -r1.40 configure.srv
--- configure.srv 19 Apr 2009 17:54:52 -0000 1.40
+++ configure.srv 30 Apr 2009 01:23:29 -0000
@@ -53,10 +53,10 @@ case "${target}" in
srv_linux_thread_db=yes
;;
i[34567]86-*-cygwin*) srv_regobj=reg-i386.o
- srv_tgtobj="win32-low.o win32-i386-low.o"
+ srv_tgtobj="i386-low.o win32-low.o win32-i386-low.o"
;;
i[34567]86-*-linux*) srv_regobj=reg-i386-linux.o
- srv_tgtobj="linux-low.o linux-i386-low.o i387-fp.o"
+ srv_tgtobj="linux-low.o linux-i386-low.o i386-low.o i387-fp.o"
srv_linux_usrregs=yes
srv_linux_regsets=yes
srv_linux_thread_db=yes
@@ -71,7 +71,7 @@ case "${target}" in
srv_mingwce=yes
;;
i[34567]86-*-mingw*) srv_regobj=reg-i386.o
- srv_tgtobj="win32-low.o win32-i386-low.o"
+ srv_tgtobj="i386-low.o win32-low.o win32-i386-low.o"
srv_mingw=yes
;;
ia64-*-linux*) srv_regobj=reg-ia64.o
@@ -170,7 +170,7 @@ case "${target}" in
srv_tgtobj="spu-low.o"
;;
x86_64-*-linux*) srv_regobj=reg-x86-64-linux.o
- srv_tgtobj="linux-low.o linux-x86-64-low.o i387-fp.o"
+ srv_tgtobj="linux-low.o linux-x86-64-low.o i386-low.o i387-fp.o"
srv_linux_regsets=yes
srv_linux_thread_db=yes
;;
Index: i386-low.c
===================================================================
RCS file: i386-low.c
diff -N i386-low.c
--- /dev/null 1 Jan 1970 00:00:00 -0000
+++ i386-low.c 30 Apr 2009 01:23:29 -0000
@@ -0,0 +1,667 @@
+/* Debug register code for the i386.
+
+ Copyright (C) 2009
+ Free Software Foundation, Inc.
+
+ This file is part of GDB.
+
+ This program is free software; you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation; either version 3 of the License, or
+ (at your option) any later version.
+
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program. If not, see <http://www.gnu.org/licenses/>. */
+
+#include "server.h"
+#include "target.h"
+#include "i386-low.h"
+
+/* Support for 8-byte wide hw watchpoints. */
+#ifndef TARGET_HAS_DR_LEN_8
+#define TARGET_HAS_DR_LEN_8 (sizeof (long) == 8)
+#endif
+
+enum target_hw_bp_type
+ {
+ hw_write = 0, /* Common HW watchpoint */
+ hw_read = 1, /* Read HW watchpoint */
+ hw_access = 2, /* Access HW watchpoint */
+ hw_execute = 3 /* Execute HW breakpoint */
+ };
+
+/* DR7 Debug Control register fields. */
+
+/* How many bits to skip in DR7 to get to R/W and LEN fields. */
+#define DR_CONTROL_SHIFT 16
+/* How many bits in DR7 per R/W and LEN field for each watchpoint. */
+#define DR_CONTROL_SIZE 4
+
+/* Watchpoint/breakpoint read/write fields in DR7. */
+#define DR_RW_EXECUTE (0x0) /* Break on instruction execution. */
+#define DR_RW_WRITE (0x1) /* Break on data writes. */
+#define DR_RW_READ (0x3) /* Break on data reads or writes. */
+
+/* This is here for completeness. No platform supports this
+ functionality yet (as of March 2001). Note that the DE flag in the
+ CR4 register needs to be set to support this. */
+#ifndef DR_RW_IORW
+#define DR_RW_IORW (0x2) /* Break on I/O reads or writes. */
+#endif
+
+/* Watchpoint/breakpoint length fields in DR7. The 2-bit left shift
+ is so we could OR this with the read/write field defined above. */
+#define DR_LEN_1 (0x0 << 2) /* 1-byte region watch or breakpoint. */
+#define DR_LEN_2 (0x1 << 2) /* 2-byte region watch. */
+#define DR_LEN_4 (0x3 << 2) /* 4-byte region watch. */
+#define DR_LEN_8 (0x2 << 2) /* 8-byte region watch (AMD64). */
+
+/* Local and Global Enable flags in DR7.
+
+ When the Local Enable flag is set, the breakpoint/watchpoint is
+ enabled only for the current task; the processor automatically
+ clears this flag on every task switch. When the Global Enable flag
+ is set, the breakpoint/watchpoint is enabled for all tasks; the
+ processor never clears this flag.
+
+ Currently, all watchpoint are locally enabled. If you need to
+ enable them globally, read the comment which pertains to this in
+ i386_insert_aligned_watchpoint below. */
+#define DR_LOCAL_ENABLE_SHIFT 0 /* Extra shift to the local enable bit. */
+#define DR_GLOBAL_ENABLE_SHIFT 1 /* Extra shift to the global enable bit. */
+#define DR_ENABLE_SIZE 2 /* Two enable bits per debug register. */
+
+/* Local and global exact breakpoint enable flags (a.k.a. slowdown
+ flags). These are only required on i386, to allow detection of the
+ exact instruction which caused a watchpoint to break; i486 and
+ later processors do that automatically. We set these flags for
+ backwards compatibility. */
+#define DR_LOCAL_SLOWDOWN (0x100)
+#define DR_GLOBAL_SLOWDOWN (0x200)
+
+/* Fields reserved by Intel. This includes the GD (General Detect
+ Enable) flag, which causes a debug exception to be generated when a
+ MOV instruction accesses one of the debug registers.
+
+ FIXME: My Intel manual says we should use 0xF800, not 0xFC00. */
+#define DR_CONTROL_RESERVED (0xFC00)
+
+/* Auxiliary helper macros. */
+
+/* A value that masks all fields in DR7 that are reserved by Intel. */
+#define I386_DR_CONTROL_MASK (~DR_CONTROL_RESERVED)
+
+/* The I'th debug register is vacant if its Local and Global Enable
+ bits are reset in the Debug Control register. */
+#define I386_DR_VACANT(state, i) \
+ (((state)->dr_control_mirror & (3 << (DR_ENABLE_SIZE * (i)))) == 0)
+
+/* Locally enable the break/watchpoint in the I'th debug register. */
+#define I386_DR_LOCAL_ENABLE(state, i) \
+ do { \
+ (state)->dr_control_mirror |= \
+ (1 << (DR_LOCAL_ENABLE_SHIFT + DR_ENABLE_SIZE * (i))); \
+ } while (0)
+
+/* Globally enable the break/watchpoint in the I'th debug register. */
+#define I386_DR_GLOBAL_ENABLE(state, i) \
+ do { \
+ (state)->dr_control_mirror |= \
+ (1 << (DR_GLOBAL_ENABLE_SHIFT + DR_ENABLE_SIZE * (i))); \
+ } while (0)
+
+/* Disable the break/watchpoint in the I'th debug register. */
+#define I386_DR_DISABLE(state, i) \
+ do { \
+ (state)->dr_control_mirror &= \
+ ~(3 << (DR_ENABLE_SIZE * (i))); \
+ } while (0)
+
+/* Set in DR7 the RW and LEN fields for the I'th debug register. */
+#define I386_DR_SET_RW_LEN(state, i,rwlen) \
+ do { \
+ (state)->dr_control_mirror &= \
+ ~(0x0f << (DR_CONTROL_SHIFT+DR_CONTROL_SIZE*(i))); \
+ (state)->dr_control_mirror |= \
+ ((rwlen) << (DR_CONTROL_SHIFT+DR_CONTROL_SIZE*(i))); \
+ } while (0)
+
+/* Get from DR7 the RW and LEN fields for the I'th debug register. */
+#define I386_DR_GET_RW_LEN(state, i) \
+ (((state)->dr_control_mirror >> (DR_CONTROL_SHIFT + DR_CONTROL_SIZE * (i))) & 0x0f)
+
+/* Did the watchpoint whose address is in the I'th register break? */
+#define I386_DR_WATCH_HIT(state,i) ((state)->dr_status_mirror & (1 << (i)))
+
+/* A macro to loop over all debug registers. */
+#define ALL_DEBUG_REGISTERS(i) for (i = 0; i < DR_NADDR; i++)
+
+/* Whether or not to print the mirrored debug registers. */
+static int maint_show_dr = 0;
+
+/* Types of operations supported by i386_handle_nonaligned_watchpoint. */
+typedef enum { WP_INSERT, WP_REMOVE, WP_COUNT } i386_wp_op_t;
+
+/* Internal functions. */
+
+/* Return the value of a 4-bit field for DR7 suitable for watching a
+ region of LEN bytes for accesses of type TYPE. LEN is assumed to
+ have the value of 1, 2, or 4. */
+static unsigned i386_length_and_rw_bits (int len, enum target_hw_bp_type type);
+
+/* Insert a watchpoint at address ADDR, which is assumed to be aligned
+ according to the length of the region to watch. LEN_RW_BITS is the
+ value of the bit-field from DR7 which describes the length and
+ access type of the region to be watched by this watchpoint. Return
+ 0 on success, -1 on failure. */
+static int i386_insert_aligned_watchpoint (struct i386_debug_reg_state *state,
+ CORE_ADDR addr,
+ unsigned len_rw_bits);
+
+/* Remove a watchpoint at address ADDR, which is assumed to be aligned
+ according to the length of the region to watch. LEN_RW_BITS is the
+ value of the bits from DR7 which describes the length and access
+ type of the region watched by this watchpoint. Return 0 on
+ success, -1 on failure. */
+static int i386_remove_aligned_watchpoint (struct i386_debug_reg_state *state,
+ CORE_ADDR addr,
+ unsigned len_rw_bits);
+
+/* Insert or remove a (possibly non-aligned) watchpoint, or count the
+ number of debug registers required to watch a region at address
+ ADDR whose length is LEN for accesses of type TYPE. Return 0 on
+ successful insertion or removal, a positive number when queried
+ about the number of registers, or -1 on failure. If WHAT is not a
+ valid value, bombs through internal_error. */
+static int i386_handle_nonaligned_watchpoint (struct i386_debug_reg_state *state,
+ i386_wp_op_t what,
+ CORE_ADDR addr, int len,
+ enum target_hw_bp_type type);
+\f
+/* Implementation. */
+
+/* Clear the reference counts and forget everything we knew about the
+ debug registers. */
+
+void
+i386_low_cleanup_dregs (struct i386_debug_reg_state *state)
+{
+ int i;
+
+ ALL_DEBUG_REGISTERS(i)
+ {
+ state->dr_mirror[i] = 0;
+ state->dr_ref_count[i] = 0;
+ }
+ state->dr_control_mirror = 0;
+ state->dr_status_mirror = 0;
+}
+
+/* Print the values of the mirrored debug registers. This is called
+ when maint_show_dr is non-zero. To set that up, type "maint
+ show-debug-regs" at GDB's prompt. */
+
+static void
+i386_show_dr (struct i386_debug_reg_state *state,
+ const char *func, CORE_ADDR addr,
+ int len, enum target_hw_bp_type type)
+{
+ int i;
+
+ printf (func);
+ if (addr || len)
+ printf (" (addr=%lx, len=%d, type=%s)",
+ (unsigned long) addr, len,
+ type == hw_write ? "data-write"
+ : (type == hw_read ? "data-read"
+ : (type == hw_access ? "data-read/write"
+ : (type == hw_execute ? "instruction-execute"
+ /* FIXME: if/when I/O read/write
+ watchpoints are supported, add them
+ here. */
+ : "??unknown??"))));
+ printf (":\n");
+ printf ("\tCONTROL (DR7): %08x STATUS (DR6): %08x\n",
+ state->dr_control_mirror, state->dr_status_mirror);
+ ALL_DEBUG_REGISTERS (i)
+ {
+ printf ("\
+\tDR%d: addr=0x%s, ref.count=%d DR%d: addr=0x%s, ref.count=%d\n",
+ i, paddr (state->dr_mirror[i]), state->dr_ref_count[i],
+ i+1, paddr (state->dr_mirror[i+1]), state->dr_ref_count[i+1]);
+ i++;
+ }
+}
+
+/* Return the value of a 4-bit field for DR7 suitable for watching a
+ region of LEN bytes for accesses of type TYPE. LEN is assumed to
+ have the value of 1, 2, or 4. */
+
+static unsigned
+i386_length_and_rw_bits (int len, enum target_hw_bp_type type)
+{
+ unsigned rw;
+
+ switch (type)
+ {
+ case hw_execute:
+ rw = DR_RW_EXECUTE;
+ break;
+ case hw_write:
+ rw = DR_RW_WRITE;
+ break;
+ case hw_read:
+ /* The i386 doesn't support data-read watchpoints. */
+ case hw_access:
+ rw = DR_RW_READ;
+ break;
+#if 0
+ /* Not yet supported. */
+ case hw_io_access:
+ rw = DR_RW_IORW;
+ break;
+#endif
+ default:
+ error ("\
+Invalid hardware breakpoint type %d in i386_length_and_rw_bits.\n",
+ (int) type);
+ }
+
+ switch (len)
+ {
+ case 1:
+ return (DR_LEN_1 | rw);
+ case 2:
+ return (DR_LEN_2 | rw);
+ case 4:
+ return (DR_LEN_4 | rw);
+ case 8:
+ if (TARGET_HAS_DR_LEN_8)
+ return (DR_LEN_8 | rw);
+ default:
+ error ("\
+Invalid hardware breakpoint length %d in i386_length_and_rw_bits.\n", len);
+ }
+}
+
+/* Insert a watchpoint at address ADDR, which is assumed to be aligned
+ according to the length of the region to watch. LEN_RW_BITS is the
+ value of the bits from DR7 which describes the length and access
+ type of the region to be watched by this watchpoint. Return 0 on
+ success, -1 on failure. */
+
+static int
+i386_insert_aligned_watchpoint (struct i386_debug_reg_state *state,
+ CORE_ADDR addr, unsigned len_rw_bits)
+{
+ int i;
+
+ /* First, look for an occupied debug register with the same address
+ and the same RW and LEN definitions. If we find one, we can
+ reuse it for this watchpoint as well (and save a register). */
+ ALL_DEBUG_REGISTERS(i)
+ {
+ if (!I386_DR_VACANT (state, i)
+ && state->dr_mirror[i] == addr
+ && I386_DR_GET_RW_LEN (state, i) == len_rw_bits)
+ {
+ state->dr_ref_count[i]++;
+ return 0;
+ }
+ }
+
+ /* Next, look for a vacant debug register. */
+ ALL_DEBUG_REGISTERS(i)
+ {
+ if (I386_DR_VACANT (state, i))
+ break;
+ }
+
+ /* No more debug registers! */
+ if (i >= DR_NADDR)
+ return -1;
+
+ /* Now set up the register I to watch our region. */
+
+ /* Record the info in our local mirrored array. */
+ state->dr_mirror[i] = addr;
+ state->dr_ref_count[i] = 1;
+ I386_DR_SET_RW_LEN (state, i, len_rw_bits);
+ /* Note: we only enable the watchpoint locally, i.e. in the current
+ task. Currently, no i386 target allows or supports global
+ watchpoints; however, if any target would want that in the
+ future, GDB should probably provide a command to control whether
+ to enable watchpoints globally or locally, and the code below
+ should use global or local enable and slow-down flags as
+ appropriate. */
+ I386_DR_LOCAL_ENABLE (state, i);
+ state->dr_control_mirror |= DR_LOCAL_SLOWDOWN;
+ state->dr_control_mirror &= I386_DR_CONTROL_MASK;
+
+ /* Finally, actually pass the info to the inferior. */
+ i386_dr_low_set_addr (i, addr);
+ i386_dr_low_set_control (state->dr_control_mirror);
+
+ return 0;
+}
+
+/* Reset a watched address for debug reg DR.
+ All implementations just do foo_set_addr (addr, 0), so this is a wrapper
+ around foo_set_addr to maintain the concept that this is a reset. */
+
+static void
+i386_dr_low_reset_addr (int dr)
+{
+ i386_dr_low_set_addr (dr, 0);
+}
+
+/* Remove a watchpoint at address ADDR, which is assumed to be aligned
+ according to the length of the region to watch. LEN_RW_BITS is the
+ value of the bits from DR7 which describes the length and access
+ type of the region watched by this watchpoint. Return 0 on
+ success, -1 on failure. */
+
+static int
+i386_remove_aligned_watchpoint (struct i386_debug_reg_state *state,
+ CORE_ADDR addr, unsigned len_rw_bits)
+{
+ int i, retval = -1;
+
+ ALL_DEBUG_REGISTERS(i)
+ {
+ if (!I386_DR_VACANT (state, i)
+ && state->dr_mirror[i] == addr
+ && I386_DR_GET_RW_LEN (state, i) == len_rw_bits)
+ {
+ if (--state->dr_ref_count[i] == 0) /* no longer in use? */
+ {
+ /* Reset our mirror. */
+ state->dr_mirror[i] = 0;
+ I386_DR_DISABLE (state, i);
+ /* Reset it in the inferior. */
+ i386_dr_low_set_control (state->dr_control_mirror);
+ i386_dr_low_reset_addr (i);
+ }
+ retval = 0;
+ }
+ }
+
+ return retval;
+}
+
+/* Insert or remove a (possibly non-aligned) watchpoint, or count the
+ number of debug registers required to watch a region at address
+ ADDR whose length is LEN for accesses of type TYPE. Return 0 on
+ successful insertion or removal, a positive number when queried
+ about the number of registers, or -1 on failure. If WHAT is not a
+ valid value, bombs through internal_error. */
+
+static int
+i386_handle_nonaligned_watchpoint (struct i386_debug_reg_state *state,
+ i386_wp_op_t what, CORE_ADDR addr, int len,
+ enum target_hw_bp_type type)
+{
+ int retval = 0, status = 0;
+ int max_wp_len = TARGET_HAS_DR_LEN_8 ? 8 : 4;
+
+ static int size_try_array[8][8] =
+ {
+ {1, 1, 1, 1, 1, 1, 1, 1}, /* Trying size one. */
+ {2, 1, 2, 1, 2, 1, 2, 1}, /* Trying size two. */
+ {2, 1, 2, 1, 2, 1, 2, 1}, /* Trying size three. */
+ {4, 1, 2, 1, 4, 1, 2, 1}, /* Trying size four. */
+ {4, 1, 2, 1, 4, 1, 2, 1}, /* Trying size five. */
+ {4, 1, 2, 1, 4, 1, 2, 1}, /* Trying size six. */
+ {4, 1, 2, 1, 4, 1, 2, 1}, /* Trying size seven. */
+ {8, 1, 2, 1, 4, 1, 2, 1}, /* Trying size eight. */
+ };
+
+ while (len > 0)
+ {
+ int align = addr % max_wp_len;
+ /* Four (eight on AMD64) is the maximum length a debug register
+ can watch. */
+ int try = (len > max_wp_len ? (max_wp_len - 1) : len - 1);
+ int size = size_try_array[try][align];
+
+ if (what == WP_COUNT)
+ {
+ /* size_try_array[] is defined such that each iteration
+ through the loop is guaranteed to produce an address and a
+ size that can be watched with a single debug register.
+ Thus, for counting the registers required to watch a
+ region, we simply need to increment the count on each
+ iteration. */
+ retval++;
+ }
+ else
+ {
+ unsigned len_rw = i386_length_and_rw_bits (size, type);
+
+ if (what == WP_INSERT)
+ status = i386_insert_aligned_watchpoint (state, addr, len_rw);
+ else if (what == WP_REMOVE)
+ status = i386_remove_aligned_watchpoint (state, addr, len_rw);
+#if 0
+ else
+ internal_error (__FILE__, __LINE__, _("\
+Invalid value %d of operation in i386_handle_nonaligned_watchpoint.\n"),
+ (int)what);
+#endif
+ /* We keep the loop going even after a failure, because some
+ of the other aligned watchpoints might still succeed
+ (e.g. if they watch addresses that are already watched,
+ in which case we just increment the reference counts of
+ occupied debug registers). If we break out of the loop
+ too early, we could cause those addresses watched by
+ other watchpoints to be disabled when breakpoint.c reacts
+ to our failure to insert this watchpoint and tries to
+ remove it. */
+ if (status)
+ retval = status;
+ }
+
+ addr += size;
+ len -= size;
+ }
+
+ return retval;
+}
+
+#define Z_PACKET_WRITE_WP '2'
+#define Z_PACKET_READ_WP '3'
+#define Z_PACKET_ACCESS_WP '4'
+
+static int
+Z_packet_to_hw_type (char type)
+{
+ switch (type)
+ {
+ case Z_PACKET_WRITE_WP: return hw_write;
+ case Z_PACKET_READ_WP: return hw_read;
+ case Z_PACKET_ACCESS_WP: return hw_access;
+ default:
+ error ("Z_packet_to_hw_type: bad watchpoint type %c", type);
+ }
+}
+
+/* Insert a watchpoint to watch a memory region which starts at
+ address ADDR and whose length is LEN bytes. Watch memory accesses
+ of the type TYPE_FROM_PACKET. Return 0 on success, -1 on failure. */
+
+int
+i386_low_insert_watchpoint (struct i386_debug_reg_state *state,
+ char type_from_packet, CORE_ADDR addr, int len)
+{
+ int retval;
+ int type = Z_packet_to_hw_type (type_from_packet);
+
+ if (((len != 1 && len !=2 && len !=4) && !(TARGET_HAS_DR_LEN_8 && len == 8))
+ || addr % len != 0)
+ {
+ retval = i386_handle_nonaligned_watchpoint (state, WP_INSERT,
+ addr, len, type);
+ }
+ else
+ {
+ unsigned len_rw = i386_length_and_rw_bits (len, type);
+
+ retval = i386_insert_aligned_watchpoint (state, addr, len_rw);
+ }
+
+ if (maint_show_dr)
+ i386_show_dr (state, "insert_watchpoint", addr, len, type);
+
+ return retval;
+}
+
+/* Remove a watchpoint that watched the memory region which starts at
+ address ADDR, whose length is LEN bytes, and for accesses of the
+ type TYPE_FROM_PACKET. Return 0 on success, -1 on failure. */
+
+int
+i386_low_remove_watchpoint (struct i386_debug_reg_state *state,
+ char type_from_packet, CORE_ADDR addr, int len)
+{
+ int retval;
+ int type = Z_packet_to_hw_type (type_from_packet);
+
+ if (((len != 1 && len !=2 && len !=4) && !(TARGET_HAS_DR_LEN_8 && len == 8))
+ || addr % len != 0)
+ {
+ retval = i386_handle_nonaligned_watchpoint (state, WP_REMOVE,
+ addr, len, type);
+ }
+ else
+ {
+ unsigned len_rw = i386_length_and_rw_bits (len, type);
+
+ retval = i386_remove_aligned_watchpoint (state, addr, len_rw);
+ }
+ if (maint_show_dr)
+ i386_show_dr (state, "remove_watchpoint", addr, len, type);
+ return retval;
+}
+
+/* Return non-zero if we can watch a memory region that starts at
+ address ADDR and whose length is LEN bytes. */
+
+int
+i386_low_region_ok_for_watchpoint (struct i386_debug_reg_state *state,
+ CORE_ADDR addr, int len)
+{
+ int nregs;
+
+ /* Compute how many aligned watchpoints we would need to cover this
+ region. */
+ nregs = i386_handle_nonaligned_watchpoint (state, WP_COUNT,
+ addr, len, hw_write);
+ return nregs <= DR_NADDR ? 1 : 0;
+}
+
+/* If the inferior has some watchpoint that triggered, set the
+ address associated with that watchpoint and return non-zero.
+ Otherwise, return zero. */
+
+CORE_ADDR
+i386_low_stopped_data_address (struct i386_debug_reg_state *state)
+{
+ CORE_ADDR addr = 0;
+ int i;
+ int rc = 0;
+
+ state->dr_status_mirror = i386_dr_low_get_status ();
+
+ ALL_DEBUG_REGISTERS(i)
+ {
+ if (I386_DR_WATCH_HIT (state, i)
+ /* This second condition makes sure DRi is set up for a data
+ watchpoint, not a hardware breakpoint. The reason is
+ that GDB doesn't call the target_stopped_data_address
+ method except for data watchpoints. In other words, I'm
+ being paranoiac. */
+ && I386_DR_GET_RW_LEN (state, i) != 0)
+ {
+ addr = state->dr_mirror[i];
+ rc = 1;
+ if (maint_show_dr)
+ i386_show_dr (state, "watchpoint_hit", addr, -1, hw_write);
+ }
+ }
+ if (maint_show_dr && addr == 0)
+ i386_show_dr (state, "stopped_data_addr", 0, 0, hw_write);
+
+ /* NOTE: gdb version checks rc != 0 here. */
+ return addr;
+}
+
+int
+i386_low_stopped_by_watchpoint (struct i386_debug_reg_state *state)
+{
+ CORE_ADDR addr = 0;
+ /* NOTE: gdb version passes boolean found/not-found result from
+ i386_stopped_data_address. */
+ addr = i386_low_stopped_data_address (state);
+ return (addr != 0);
+}
+\f
+/* Support for h/w breakpoints.
+ This support is not currently used, kept for reference. */
+
+/* Return non-zero if the inferior has some break/watchpoint that
+ triggered. */
+
+int
+i386_low_stopped_by_hwbp (struct i386_debug_reg_state *state)
+{
+ int i;
+
+ state->dr_status_mirror = i386_dr_low_get_status ();
+ if (maint_show_dr)
+ i386_show_dr (state, "stopped_by_hwbp", 0, 0, hw_execute);
+
+ ALL_DEBUG_REGISTERS(i)
+ {
+ if (I386_DR_WATCH_HIT (state, i))
+ return 1;
+ }
+
+ return 0;
+}
+
+/* Insert a hardware-assisted breakpoint at ADDR.
+ Return 0 on success, -1 on failure. */
+
+int
+i386_low_insert_hw_breakpoint (struct i386_debug_reg_state *state,
+ CORE_ADDR addr)
+{
+ unsigned len_rw = i386_length_and_rw_bits (1, hw_execute);
+ int retval = i386_insert_aligned_watchpoint (state, addr, len_rw);
+
+ if (maint_show_dr)
+ i386_show_dr (state, "insert_hwbp", addr, 1, hw_execute);
+
+ return retval;
+}
+
+/* Remove a hardware-assisted breakpoint at ADDR.
+ Return 0 on success, -1 on failure. */
+
+int
+i386_low_remove_hw_breakpoint (struct i386_debug_reg_state *state,
+ CORE_ADDR addr)
+{
+ unsigned len_rw = i386_length_and_rw_bits (1, hw_execute);
+ int retval = i386_remove_aligned_watchpoint (state, addr, len_rw);
+
+ if (maint_show_dr)
+ i386_show_dr (state, "remove_hwbp", addr, 1, hw_execute);
+
+ return retval;
+}
Index: i386-low.h
===================================================================
RCS file: i386-low.h
diff -N i386-low.h
--- /dev/null 1 Jan 1970 00:00:00 -0000
+++ i386-low.h 30 Apr 2009 01:23:29 -0000
@@ -0,0 +1,118 @@
+/* Misc. low level support for i386.
+
+ Copyright (C) 2009
+ Free Software Foundation, Inc.
+
+ This file is part of GDB.
+
+ This program is free software; you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation; either version 3 of the License, or
+ (at your option) any later version.
+
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program. If not, see <http://www.gnu.org/licenses/>. */
+
+/* Support for hardware watchpoints and breakpoints using the i386
+ debug registers.
+
+ This provides several functions for inserting and removing
+ hardware-assisted breakpoints and watchpoints, testing if one or
+ more of the watchpoints triggered and at what address, checking
+ whether a given region can be watched, etc.
+
+ The functions below implement debug registers sharing by reference
+ counts, and allow to watch regions up to 16 bytes long
+ (32 bytes on 64 bit hosts). */
+
+
+/* Debug registers' indices. */
+#define DR_FIRSTADDR 0
+#define DR_LASTADDR 3
+#define DR_NADDR 4 /* The number of debug address registers. */
+#define DR_STATUS 6
+#define DR_CONTROL 7
+
+/* Global state needed to track h/w watchpoints. */
+
+struct i386_debug_reg_state
+{
+ /* Mirror the inferior's DRi registers. We keep the status and
+ control registers separated because they don't hold addresses. */
+ CORE_ADDR dr_mirror[DR_NADDR];
+ unsigned dr_status_mirror, dr_control_mirror;
+
+ /* Reference counts for each debug register. */
+ int dr_ref_count[DR_NADDR];
+};
+
+/* Clear the reference counts and forget everything we knew about DRi. */
+extern void i386_low_cleanup_dregs (struct i386_debug_reg_state *state);
+
+/* Insert a watchpoint to watch a memory region which starts at
+ address ADDR and whose length is LEN bytes. Watch memory accesses
+ of the type TYPE_FROM_PACKET. Return 0 on success, -1 on failure. */
+extern int i386_low_insert_watchpoint (struct i386_debug_reg_state *state,
+ char type_from_packet, CORE_ADDR addr,
+ int len);
+
+/* Remove a watchpoint that watched the memory region which starts at
+ address ADDR, whose length is LEN bytes, and for accesses of the
+ type TYPE_FROM_PACKET. Return 0 on success, -1 on failure. */
+extern int i386_low_remove_watchpoint (struct i386_debug_reg_state *state,
+ char type_from_packet, CORE_ADDR addr,
+ int len);
+
+/* Return non-zero if we can watch a memory region that starts at
+ address ADDR and whose length is LEN bytes. */
+extern int i386_low_region_ok_for_watchpoint (struct i386_debug_reg_state *state,
+ CORE_ADDR addr, int len);
+
+/* If the inferior has some break/watchpoint that triggered, set
+ the address associated with that break/watchpoint and return
+ true. Otherwise, return false. */
+extern CORE_ADDR i386_low_stopped_data_address (struct i386_debug_reg_state *state);
+
+extern int i386_low_stopped_by_watchpoint (struct i386_debug_reg_state *state);
+
+/* Return non-zero if the inferior has some break/watchpoint that
+ triggered. */
+extern int i386_low_stopped_by_hwbp (struct i386_debug_reg_state *state);
+
+/* Insert a hardware-assisted breakpoint at ADDR.
+ Return 0 on success, -1 on failure. */
+extern int i386_low_insert_hw_breakpoint (struct i386_debug_reg_state *state,
+ CORE_ADDR addr);
+
+/* Remove a hardware-assisted breakpoint at ADDR.
+ Return 0 on success, -1 on failure. */
+extern int i386_low_remove_hw_breakpoint (struct i386_debug_reg_state *state,
+ CORE_ADDR addr);
+\f
+/* Each target needs to provide several low-level functions
+ that will be called to insert watchpoints and hardware breakpoints
+ into the inferior, remove them, and check their status. These
+ functions are:
+
+ i386_dr_low_set_control -- set the debug control (DR7)
+ register to a given value
+
+ i386_dr_low_set_addr -- put an address into one debug register
+
+ i386_dr_low_get_status -- return the value of the debug
+ status (DR6) register.
+*/
+
+/* Pass the address ADDR to the inferior in the I'th debug register. */
+extern void i386_dr_low_set_addr (int i, CORE_ADDR addr);
+
+/* Pass the value VAL to the inferior in the DR7 debug control register. */
+extern void i386_dr_low_set_control (unsigned val);
+
+/* Get the value of the DR6 debug status register from the inferior. */
+extern unsigned i386_dr_low_get_status (void);
Index: linux-i386-low.c
===================================================================
RCS file: /cvs/src/src/gdb/gdbserver/linux-i386-low.c,v
retrieving revision 1.19
diff -u -p -r1.19 linux-i386-low.c
--- linux-i386-low.c 22 Mar 2009 23:57:10 -0000 1.19
+++ linux-i386-low.c 30 Apr 2009 01:23:29 -0000
@@ -17,9 +17,11 @@
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>. */
+#include <stddef.h>
#include "server.h"
#include "linux-low.h"
#include "i387-fp.h"
+#include "i386-low.h"
#include "gdb_proc_service.h"
@@ -33,10 +35,14 @@
#define PTRACE_GET_THREAD_AREA 25
#endif
+struct arch_process_info
+{
+ struct i386_debug_reg_state debug_reg_state;
+};
+
/* Defined in auto-generated file reg-i386-linux.c. */
void init_registers_i386_linux (void);
-
/* This module only supports access to the general purpose registers. */
#define i386_num_regs 16
@@ -187,6 +193,148 @@ i386_breakpoint_at (CORE_ADDR pc)
return 0;
}
+\f
+/* Support for debug registers. */
+
+static unsigned long
+i386_linux_dr_get (ptid_t ptid, int regnum)
+{
+ int tid;
+ unsigned long value;
+
+ tid = TIDGET (ptid);
+ if (tid == 0)
+ tid = PIDGET (ptid);
+
+ errno = 0;
+ value = ptrace (PTRACE_PEEKUSER, tid,
+ offsetof (struct user, u_debugreg[regnum]), 0);
+ if (errno != 0)
+ error ("Couldn't read debug register");
+
+ return value;
+}
+
+static void
+i386_linux_dr_set (ptid_t ptid, int regnum, unsigned long value)
+{
+ int tid;
+
+ tid = TIDGET (ptid);
+ if (tid == 0)
+ tid = PIDGET (ptid);
+
+ errno = 0;
+ ptrace (PTRACE_POKEUSER, tid,
+ offsetof (struct user, u_debugreg[regnum]), value);
+ if (errno != 0)
+ error ("Couldn't write debug register");
+}
+
+/* Pass the address ADDR to the inferior in debug register REGNUM. */
+
+void
+i386_dr_low_set_addr (int regnum, CORE_ADDR addr)
+{
+ struct inferior_list_entry *lp;
+
+ if (! (regnum >= 0 && regnum <= DR_LASTADDR - DR_FIRSTADDR))
+ error ("Invalid debug register");
+
+ for (lp = all_lwps.head; lp; lp = lp->next)
+ {
+ struct lwp_info *lwp = (struct lwp_info *) lp;
+ i386_linux_dr_set (ptid_of (lwp), DR_FIRSTADDR + regnum, addr);
+ }
+}
+
+/* Pass the value VAL to the inferior in the DR7 debug control register. */
+
+void
+i386_dr_low_set_control (unsigned control)
+{
+ struct inferior_list_entry *lp;
+
+ for (lp = all_lwps.head; lp; lp = lp->next)
+ {
+ struct lwp_info *lwp = (struct lwp_info *) lp;
+ i386_linux_dr_set (ptid_of (lwp), DR_CONTROL, control);
+ }
+}
+
+/* Get the value of the DR6 debug status register from the inferior. */
+
+unsigned
+i386_dr_low_get_status (void)
+{
+ ptid_t inferior_ptid = ptid_of (get_thread_lwp (current_inferior));
+ return i386_linux_dr_get (inferior_ptid, DR_STATUS);
+}
+\f
+/* Watchpoint support. */
+
+static int
+i386_insert_watchpoint (struct arch_process_info *arch_private,
+ char type, CORE_ADDR addr, int len)
+{
+ return i386_low_insert_watchpoint (&arch_private->debug_reg_state,
+ type, addr, len);
+}
+
+static int
+i386_remove_watchpoint (struct arch_process_info *arch_private,
+ char type, CORE_ADDR addr, int len)
+{
+ return i386_low_remove_watchpoint (&arch_private->debug_reg_state,
+ type, addr, len);
+}
+
+static int
+i386_stopped_by_watchpoint (struct arch_process_info *arch_private)
+{
+ return i386_low_stopped_by_watchpoint (&arch_private->debug_reg_state);
+}
+
+static CORE_ADDR
+i386_stopped_data_address (struct arch_process_info *arch_private)
+{
+ return i386_low_stopped_data_address (&arch_private->debug_reg_state);
+}
+\f
+/* Called when a new process is created. */
+
+struct arch_process_info *
+i386_linux_new_process (int pid, int attached)
+{
+ struct arch_process_info *info = xcalloc (1, sizeof (*info));
+
+ return info;
+}
+
+/* Called when a new thread is detected.
+ INITIAL is non-zero for the main thread, zero otherwise. */
+
+static void
+i386_linux_new_thread (struct lwp_info *lwp, int initial)
+{
+ /* The initial thread has debug regs set later during process
+ creation/attaching handling. */
+
+ if (! initial)
+ {
+ int i;
+ ptid_t ptid = ptid_of (lwp);
+ int pid = PIDGET (ptid);
+ struct process_info *proc = find_process_pid (pid);
+ struct arch_process_info *arch_private = proc->private->arch_private;
+ struct i386_debug_reg_state *state = &arch_private->debug_reg_state;
+
+ for (i = DR_FIRSTADDR; i <= DR_LASTADDR; i++)
+ i386_linux_dr_set (ptid, i, state->dr_mirror[i]);
+
+ i386_linux_dr_set (ptid, DR_CONTROL, state->dr_control_mirror);
+ }
+}
struct linux_target_ops the_low_target = {
init_registers_i386_linux,
@@ -201,10 +349,12 @@ struct linux_target_ops the_low_target =
NULL,
1,
i386_breakpoint_at,
+ i386_insert_watchpoint,
+ i386_remove_watchpoint,
+ i386_stopped_by_watchpoint,
+ i386_stopped_data_address,
NULL,
NULL,
- NULL,
- NULL,
- NULL,
- NULL,
+ i386_linux_new_process,
+ i386_linux_new_thread
};
Index: linux-low.c
===================================================================
RCS file: /cvs/src/src/gdb/gdbserver/linux-low.c,v
retrieving revision 1.97
diff -u -p -r1.97 linux-low.c
--- linux-low.c 3 Apr 2009 11:40:02 -0000 1.97
+++ linux-low.c 30 Apr 2009 06:26:54 -0000
@@ -120,6 +120,7 @@ static int must_set_ptrace_flags;
control of gdbserver have the same architecture. */
static int new_inferior;
+static void notify_low_target_new_thread (struct lwp_info *lwp, int initial);
static void linux_resume_one_lwp (struct inferior_list_entry *entry,
int step, int signal, siginfo_t *info);
static void linux_resume (struct thread_resume *resume_info, size_t n);
@@ -179,6 +180,9 @@ linux_add_process (int pid, int attached
proc = add_process (pid, attached);
proc->private = xcalloc (1, sizeof (*proc->private));
+ if (the_low_target.new_process != NULL)
+ proc->private->arch_private = the_low_target.new_process (pid, attached);
+
return proc;
}
@@ -188,6 +192,7 @@ linux_add_process (int pid, int attached
static void
linux_remove_process (struct process_info *process)
{
+ free (process->private->arch_private);
free (process->private);
remove_process (process);
}
@@ -231,6 +236,7 @@ handle_extended_wait (struct lwp_info *e
ptid = ptid_build (pid_of (event_child), new_pid, 0);
new_lwp = (struct lwp_info *) add_lwp (ptid);
add_thread (ptid, new_lwp);
+ notify_low_target_new_thread (new_lwp, 0);
/* Normally we will get the pending SIGSTOP. But in some cases
we might get another signal delivered to the group first.
@@ -313,6 +319,18 @@ add_lwp (ptid_t ptid)
return lwp;
}
+/* Notify the backend that we have a new thread, be it the main thread
+ or a later one.
+ INITIAL is non-zero for the main thread, zero otherwise.
+ NOTE: This must be called when the thread is stopped. */
+
+static void
+notify_low_target_new_thread (struct lwp_info *lwp, int initial)
+{
+ if (the_low_target.new_thread != NULL)
+ the_low_target.new_thread (lwp, initial);
+}
+
/* Start an inferior process and returns its pid.
ALLARGS is a vector of program-name and args. */
@@ -354,6 +372,8 @@ linux_create_inferior (char *program, ch
ptid = ptid_build (pid, pid, 0);
new_lwp = add_lwp (ptid);
add_thread (ptid, new_lwp);
+ /* We can't call notify_low_target_new_thread there, the thread isn't
+ stopped. Piggyback on must_set_ptrace_flags and call it then. */
must_set_ptrace_flags = 1;
return pid;
@@ -401,6 +421,7 @@ linux_attach_lwp_1 (unsigned long lwpid,
new_lwp = (struct lwp_info *) add_lwp (ptid);
add_thread (ptid, new_lwp);
+ notify_low_target_new_thread (new_lwp, initial);
/* The next time we wait for this LWP we'll see a SIGSTOP as PTRACE_ATTACH
brings it to a halt.
@@ -1261,6 +1282,7 @@ retry:
if (must_set_ptrace_flags)
{
ptrace (PTRACE_SETOPTIONS, lwpid_of (lwp), 0, PTRACE_O_TRACECLONE);
+ notify_low_target_new_thread (lwp, 1);
must_set_ptrace_flags = 0;
}
/* If we are waiting for a particular child, and it exited,
@@ -2599,7 +2623,11 @@ static int
linux_insert_watchpoint (char type, CORE_ADDR addr, int len)
{
if (the_low_target.insert_watchpoint != NULL)
- return the_low_target.insert_watchpoint (type, addr, len);
+ {
+ struct process_info *proc = current_process ();
+ return the_low_target.insert_watchpoint (proc->private->arch_private,
+ type, addr, len);
+ }
else
/* Unsupported (see target.h). */
return 1;
@@ -2609,7 +2637,11 @@ static int
linux_remove_watchpoint (char type, CORE_ADDR addr, int len)
{
if (the_low_target.remove_watchpoint != NULL)
- return the_low_target.remove_watchpoint (type, addr, len);
+ {
+ struct process_info *proc = current_process ();
+ return the_low_target.remove_watchpoint (proc->private->arch_private,
+ type, addr, len);
+ }
else
/* Unsupported (see target.h). */
return 1;
@@ -2619,7 +2651,10 @@ static int
linux_stopped_by_watchpoint (void)
{
if (the_low_target.stopped_by_watchpoint != NULL)
- return the_low_target.stopped_by_watchpoint ();
+ {
+ struct process_info *proc = current_process ();
+ return the_low_target.stopped_by_watchpoint (proc->private->arch_private);
+ }
else
return 0;
}
@@ -2628,7 +2663,10 @@ static CORE_ADDR
linux_stopped_data_address (void)
{
if (the_low_target.stopped_data_address != NULL)
- return the_low_target.stopped_data_address ();
+ {
+ struct process_info *proc = current_process ();
+ return the_low_target.stopped_data_address (proc->private->arch_private);
+ }
else
return 0;
}
Index: linux-low.h
===================================================================
RCS file: /cvs/src/src/gdb/gdbserver/linux-low.h,v
retrieving revision 1.28
diff -u -p -r1.28 linux-low.h
--- linux-low.h 1 Apr 2009 22:50:24 -0000 1.28
+++ linux-low.h 30 Apr 2009 01:23:29 -0000
@@ -54,8 +54,13 @@ struct process_info_private
/* Connection to the libthread_db library. */
td_thragent_t *thread_agent;
+
+ /* Target-specific additions. */
+ struct arch_process_info *arch_private;
};
+struct lwp_info;
+
struct linux_target_ops
{
/* Architecture-specific setup. */
@@ -75,26 +80,37 @@ struct linux_target_ops
int breakpoint_len;
CORE_ADDR (*breakpoint_reinsert_addr) (void);
-
int decr_pc_after_break;
int (*breakpoint_at) (CORE_ADDR pc);
/* Watchpoint related functions. See target.h for comments. */
- int (*insert_watchpoint) (char type, CORE_ADDR addr, int len);
- int (*remove_watchpoint) (char type, CORE_ADDR addr, int len);
- int (*stopped_by_watchpoint) (void);
- CORE_ADDR (*stopped_data_address) (void);
+ int (*insert_watchpoint) (struct arch_process_info *arch_private,
+ char type, CORE_ADDR addr, int len);
+ int (*remove_watchpoint) (struct arch_process_info *arch_private,
+ char type, CORE_ADDR addr, int len);
+ int (*stopped_by_watchpoint) (struct arch_process_info *arch_private);
+ CORE_ADDR (*stopped_data_address) (struct arch_process_info *arch_private);
/* Hooks to reformat register data for PEEKUSR/POKEUSR (in particular
for registers smaller than an xfer unit). */
void (*collect_ptrace_register) (int regno, char *buf);
void (*supply_ptrace_register) (int regno, const char *buf);
+
+ /* Hook to call when a new process is created or attached to. */
+ struct arch_process_info * (*new_process) (int pid, int attached);
+
+ /* Hook to call when a new thread is detected.
+ INITIAL is non-zero for the main thread, zero otherwise. */
+ void (*new_thread) (struct lwp_info *, int initial);
};
extern struct linux_target_ops the_low_target;
+#define ptid_of(proc) ((proc)->head.id)
#define pid_of(proc) ptid_get_pid ((proc)->head.id)
#define lwpid_of(proc) ptid_get_lwp ((proc)->head.id)
+#define PIDGET(ptid) ptid_get_pid (ptid)
+#define TIDGET(ptid) ptid_get_lwp (ptid)
#define get_lwp(inf) ((struct lwp_info *)(inf))
#define get_thread_lwp(thr) (get_lwp (inferior_target_data (thr)))
Index: linux-x86-64-low.c
===================================================================
RCS file: /cvs/src/src/gdb/gdbserver/linux-x86-64-low.c,v
retrieving revision 1.22
diff -u -p -r1.22 linux-x86-64-low.c
--- linux-x86-64-low.c 22 Mar 2009 23:57:10 -0000 1.22
+++ linux-x86-64-low.c 30 Apr 2009 01:23:29 -0000
@@ -18,9 +18,11 @@
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>. */
+#include <stddef.h>
#include "server.h"
#include "linux-low.h"
#include "i387-fp.h"
+#include "i386-low.h"
#include "gdb_proc_service.h"
@@ -45,6 +47,11 @@ void init_registers_x86_64_linux (void);
#define ARCH_GET_GS 0x1004
#endif
+struct arch_process_info
+{
+ struct i386_debug_reg_state debug_reg_state;
+};
+
static int x86_64_regmap[] = {
RAX * 8, RBX * 8, RCX * 8, RDX * 8,
RSI * 8, RDI * 8, RBP * 8, RSP * 8,
@@ -161,6 +168,148 @@ x86_64_breakpoint_at (CORE_ADDR pc)
return 0;
}
+\f
+/* Support for debug registers. */
+
+static unsigned long
+x86_64_linux_dr_get (ptid_t ptid, int regnum)
+{
+ int tid;
+ unsigned long value;
+
+ tid = TIDGET (ptid);
+ if (tid == 0)
+ tid = PIDGET (ptid);
+
+ errno = 0;
+ value = ptrace (PTRACE_PEEKUSER, tid,
+ offsetof (struct user, u_debugreg[regnum]), 0);
+ if (errno != 0)
+ error ("Couldn't read debug register");
+
+ return value;
+}
+
+static void
+x86_64_linux_dr_set (ptid_t ptid, int regnum, unsigned long value)
+{
+ int tid;
+
+ tid = TIDGET (ptid);
+ if (tid == 0)
+ tid = PIDGET (ptid);
+
+ errno = 0;
+ ptrace (PTRACE_POKEUSER, tid,
+ offsetof (struct user, u_debugreg[regnum]), value);
+ if (errno != 0)
+ error ("Couldn't write debug register");
+}
+
+/* Pass the address ADDR to the inferior in debug register REGNUM. */
+
+void
+i386_dr_low_set_addr (int regnum, CORE_ADDR addr)
+{
+ struct inferior_list_entry *lp;
+
+ if (! (regnum >= 0 && regnum <= DR_LASTADDR - DR_FIRSTADDR))
+ error ("Invalid debug register");
+
+ for (lp = all_lwps.head; lp; lp = lp->next)
+ {
+ struct lwp_info *lwp = (struct lwp_info *) lp;
+ x86_64_linux_dr_set (ptid_of (lwp), DR_FIRSTADDR + regnum, addr);
+ }
+}
+
+/* Pass the value VAL to the inferior in the DR7 debug control register. */
+
+void
+i386_dr_low_set_control (unsigned control)
+{
+ struct inferior_list_entry *lp;
+
+ for (lp = all_lwps.head; lp; lp = lp->next)
+ {
+ struct lwp_info *lwp = (struct lwp_info *) lp;
+ x86_64_linux_dr_set (ptid_of (lwp), DR_CONTROL, control);
+ }
+}
+
+/* Get the value of the DR6 debug status register from the inferior. */
+
+unsigned
+i386_dr_low_get_status (void)
+{
+ ptid_t inferior_ptid = ptid_of (get_thread_lwp (current_inferior));
+ return x86_64_linux_dr_get (inferior_ptid, DR_STATUS);
+}
+\f
+/* Watchpoint support. */
+
+static int
+x86_64_insert_watchpoint (struct arch_process_info *arch_private,
+ char type, CORE_ADDR addr, int len)
+{
+ return i386_low_insert_watchpoint (&arch_private->debug_reg_state,
+ type, addr, len);
+}
+
+static int
+x86_64_remove_watchpoint (struct arch_process_info *arch_private,
+ char type, CORE_ADDR addr, int len)
+{
+ return i386_low_remove_watchpoint (&arch_private->debug_reg_state,
+ type, addr, len);
+}
+
+static int
+x86_64_stopped_by_watchpoint (struct arch_process_info *arch_private)
+{
+ return i386_low_stopped_by_watchpoint (&arch_private->debug_reg_state);
+}
+
+static CORE_ADDR
+x86_64_stopped_data_address (struct arch_process_info *arch_private)
+{
+ return i386_low_stopped_data_address (&arch_private->debug_reg_state);
+}
+\f
+/* Called when a new process is created. */
+
+struct arch_process_info *
+x86_64_linux_new_process (int pid, int attached)
+{
+ struct arch_process_info *info = xcalloc (1, sizeof (*info));
+
+ return info;
+}
+
+/* Called when a new thread is detected.
+ INITIAL is non-zero for the main thread, zero otherwise. */
+
+static void
+x86_64_linux_new_thread (struct lwp_info *lwp, int initial)
+{
+ /* The initial thread has debug regs set later during process
+ creation/attaching handling. */
+
+ if (! initial)
+ {
+ int i;
+ ptid_t ptid = ptid_of (lwp);
+ int pid = PIDGET (ptid);
+ struct process_info *proc = find_process_pid (pid);
+ struct arch_process_info *arch_private = proc->private->arch_private;
+ struct i386_debug_reg_state *state = &arch_private->debug_reg_state;
+
+ for (i = DR_FIRSTADDR; i <= DR_LASTADDR; i++)
+ x86_64_linux_dr_set (ptid, i, state->dr_mirror[i]);
+
+ x86_64_linux_dr_set (ptid, DR_CONTROL, state->dr_control_mirror);
+ }
+}
struct linux_target_ops the_low_target = {
init_registers_x86_64_linux,
@@ -175,10 +324,12 @@ struct linux_target_ops the_low_target =
NULL,
1,
x86_64_breakpoint_at,
+ x86_64_insert_watchpoint,
+ x86_64_remove_watchpoint,
+ x86_64_stopped_by_watchpoint,
+ x86_64_stopped_data_address,
NULL,
NULL,
- NULL,
- NULL,
- NULL,
- NULL,
+ x86_64_linux_new_process,
+ x86_64_linux_new_thread
};
Index: server.h
===================================================================
RCS file: /cvs/src/src/gdb/gdbserver/server.h,v
retrieving revision 1.56
diff -u -p -r1.56 server.h
--- server.h 3 Apr 2009 20:15:51 -0000 1.56
+++ server.h 30 Apr 2009 01:23:29 -0000
@@ -405,6 +405,7 @@ void perror_with_name (const char *strin
void error (const char *string,...) ATTR_NORETURN ATTR_FORMAT (printf, 1, 2);
void fatal (const char *string,...) ATTR_NORETURN ATTR_FORMAT (printf, 1, 2);
void warning (const char *string,...) ATTR_FORMAT (printf, 1, 2);
+char *paddr (CORE_ADDR addr);
/* Maximum number of bytes to read/write at once. The value here
is chosen to fill up a packet (the headers account for the 32). */
Index: utils.c
===================================================================
RCS file: /cvs/src/src/gdb/gdbserver/utils.c,v
retrieving revision 1.18
diff -u -p -r1.18 utils.c
--- utils.c 19 Jan 2009 00:16:46 -0000 1.18
+++ utils.c 30 Apr 2009 01:23:29 -0000
@@ -170,3 +170,37 @@ warning (const char *string,...)
fprintf (stderr, "\n");
va_end (args);
}
+
+/* temporary storage using circular buffer */
+#define NUMCELLS 4
+#define CELLSIZE 50
+static char *
+get_cell (void)
+{
+ static char buf[NUMCELLS][CELLSIZE];
+ static int cell = 0;
+ if (++cell >= NUMCELLS)
+ cell = 0;
+ return buf[cell];
+}
+
+static int
+xsnprintf (char *str, size_t size, const char *format, ...)
+{
+ va_list args;
+ int ret;
+
+ va_start (args, format);
+ ret = vsnprintf (str, size, format, args);
+ va_end (args);
+
+ return ret;
+}
+
+char *
+paddr (CORE_ADDR addr)
+{
+ char *str = get_cell ();
+ xsnprintf (str, CELLSIZE, "%lx", (long) addr);
+ return str;
+}
Index: win32-arm-low.c
===================================================================
RCS file: /cvs/src/src/gdb/gdbserver/win32-arm-low.c,v
retrieving revision 1.8
diff -u -p -r1.8 win32-arm-low.c
--- win32-arm-low.c 3 Jan 2009 05:57:57 -0000 1.8
+++ win32-arm-low.c 30 Apr 2009 01:23:29 -0000
@@ -122,4 +122,9 @@ struct win32_target_ops the_low_target =
NULL, /* single_step */
(const unsigned char *) &arm_wince_breakpoint,
arm_wince_breakpoint_len,
+ /* Watchpoint related functions. See target.h for comments. */
+ NULL, /* insert_watchpoint */
+ NULL, /* remove_watchpoint */
+ NULL, /* stopped_by_watchpoint */
+ NULL /* stopped_data_address */
};
Index: win32-i386-low.c
===================================================================
RCS file: /cvs/src/src/gdb/gdbserver/win32-i386-low.c,v
retrieving revision 1.14
diff -u -p -r1.14 win32-i386-low.c
--- win32-i386-low.c 3 Jan 2009 05:57:57 -0000 1.14
+++ win32-i386-low.c 30 Apr 2009 01:23:29 -0000
@@ -17,6 +17,7 @@
#include "server.h"
#include "win32-low.h"
+#include "i386-low.h"
#define FCS_REGNUM 27
#define FOP_REGNUM 31
@@ -31,6 +32,42 @@ static unsigned dr[8];
static int debug_registers_changed = 0;
static int debug_registers_used = 0;
+/* Pass the address ADDR to the inferior in the I'th debug register.
+ Here we just store the address in dr array, the registers will be
+ actually set up when windows_continue is called. */
+
+void
+i386_dr_low_set_addr (int i, CORE_ADDR addr)
+{
+ if (i < 0 || i > 3)
+ return;
+ dr[i] = (unsigned) addr;
+ debug_registers_changed = 1;
+ debug_registers_used = 1;
+}
+
+/* Pass the value VAL to the inferior in the DR7 debug control register.
+ Here we just store the address in D_REGS, the watchpoint
+ will be actually set up in windows_wait. */
+
+void
+i386_dr_low_set_control (unsigned val)
+{
+ dr[7] = val;
+ debug_registers_changed = 1;
+ debug_registers_used = 1;
+}
+
+/* Get the value of the DR6 debug status register from the inferior.
+ Here we just return the value stored in dr[6]
+ by the last call to thread_rec for current_event.dwThreadId id. */
+
+unsigned
+i386_dr_low_get_status (void)
+{
+ return dr[6];
+}
+
static void
i386_initial_stuff (void)
{
@@ -205,4 +242,8 @@ struct win32_target_ops the_low_target =
i386_single_step,
NULL, /* breakpoint */
0, /* breakpoint_len */
+ i386_insert_watchpoint,
+ i386_remove_watchpoint,
+ i386_stopped_by_watchpoint,
+ i386_stopped_data_address
};
Index: win32-low.c
===================================================================
RCS file: /cvs/src/src/gdb/gdbserver/win32-low.c,v
retrieving revision 1.35
diff -u -p -r1.35 win32-low.c
--- win32-low.c 1 Apr 2009 22:50:24 -0000 1.35
+++ win32-low.c 30 Apr 2009 01:23:29 -0000
@@ -228,6 +228,48 @@ child_delete_thread (DWORD pid, DWORD ti
delete_thread_info (thread);
}
+/* These watchpoint related wrapper functions simply pass on the function call
+ if the target has registered a corresponding function. */
+
+static int
+win32_insert_watchpoint (char type, CORE_ADDR addr, int len)
+{
+ if (the_low_target.insert_watchpoint != NULL)
+ return the_low_target.insert_watchpoint (type, addr, len);
+ else
+ /* Unsupported (see target.h). */
+ return 1;
+}
+
+static int
+win32_remove_watchpoint (char type, CORE_ADDR addr, int len)
+{
+ if (the_low_target.remove_watchpoint != NULL)
+ return the_low_target.remove_watchpoint (type, addr, len);
+ else
+ /* Unsupported (see target.h). */
+ return 1;
+}
+
+static int
+win32_stopped_by_watchpoint (void)
+{
+ if (the_low_target.stopped_by_watchpoint != NULL)
+ return the_low_target.stopped_by_watchpoint ();
+ else
+ return 0;
+}
+
+static CORE_ADDR
+win32_stopped_data_address (void)
+{
+ if (the_low_target.stopped_data_address != NULL)
+ return the_low_target.stopped_data_address ();
+ else
+ return 0;
+}
+
+
/* Transfer memory from/to the debugged process. */
static int
child_xfer_memory (CORE_ADDR memaddr, char *our, int len,
@@ -1697,10 +1739,10 @@ static struct target_ops win32_target_op
NULL,
win32_request_interrupt,
NULL,
- NULL,
- NULL,
- NULL,
- NULL,
+ win32_insert_watchpoint,
+ win32_remove_watchpoint,
+ win32_stopped_by_watchpoint,
+ win32_stopped_data_address,
NULL,
NULL,
NULL,
Index: win32-low.h
===================================================================
RCS file: /cvs/src/src/gdb/gdbserver/win32-low.h,v
retrieving revision 1.9
diff -u -p -r1.9 win32-low.h
--- win32-low.h 3 Jan 2009 05:57:57 -0000 1.9
+++ win32-low.h 30 Apr 2009 01:23:29 -0000
@@ -70,6 +70,13 @@ struct win32_target_ops
const unsigned char *breakpoint;
int breakpoint_len;
+
+ /* Watchpoint related functions. See target.h for comments. */
+ int (*insert_watchpoint) (char type, CORE_ADDR addr, int len);
+ int (*remove_watchpoint) (char type, CORE_ADDR addr, int len);
+ int (*stopped_by_watchpoint) (void);
+ CORE_ADDR (*stopped_data_address) (void);
+
};
extern struct win32_target_ops the_low_target;
^ permalink raw reply [flat|nested] 18+ messages in thread
* RE: [RFA] i386/amd64 h/w watchpoints in gdbserver
2009-04-30 7:19 [RFA] i386/amd64 h/w watchpoints in gdbserver Doug Evans
@ 2009-05-01 8:10 ` Pierre Muller
2009-05-18 23:11 ` Doug Evans
1 sibling, 0 replies; 18+ messages in thread
From: Pierre Muller @ 2009-05-01 8:10 UTC (permalink / raw)
To: 'Doug Evans', gdb-patches
Hi Doug,
I think that your patch seems to be globally OK,
but it is missing some parts
for the win32 support:
You added the i386_debug_reg_state struct,
but forgot to add that to the win32 part of your patch.
I wrote a minimal change so that I was able to use your
code.
I only tested it faintly, and it seems to work.
What is still wrong is that we still use
default_region_ok_for_hw_watchpoint,
this for instance generates a failure if I try to
set a watchpoint on a 8-byte long address
(which is possible using 2 debug registers).
But implementing this would require more changes, so I
suppose that it is better to leave that for later.
Anyhow, with the patch below, it does add
hardware support for win32 gdbserver, and as such
should be accepted IMHO.
Pierre Muller
Pascal language support maintainer for GDB
PS: By the way, what is the current status of the win64 gdbserver?
I thought that there was a patch submitted, on?
>>>>>>>>>>>>>>>>>>>>>>><<<
Here is an updated diff for win32-i386-low that allowed me to
compile gdbserver successfully for cygwin.
$ cvs diff -up win32-i386-low.c
Index: win32-i386-low.c
===================================================================
RCS file: /cvs/src/src/gdb/gdbserver/win32-i386-low.c,v
retrieving revision 1.14
diff -u -p -r1.14 win32-i386-low.c
--- win32-i386-low.c 3 Jan 2009 05:57:57 -0000 1.14
+++ win32-i386-low.c 1 May 2009 08:01:28 -0000
@@ -17,6 +17,7 @@
#include "server.h"
#include "win32-low.h"
+#include "i386-low.h"
#define FCS_REGNUM 27
#define FOP_REGNUM 31
@@ -26,15 +27,77 @@
/* Defined in auto-generated file reg-i386.c. */
void init_registers_i386 (void);
-static unsigned dr[8];
+struct i386_debug_reg_state debug_reg_state;
static int debug_registers_changed = 0;
static int debug_registers_used = 0;
+/* Pass the address ADDR to the inferior in the I'th debug register.
+ Here we just store the address in dr array, the registers will be
+ actually set up when windows_continue is called. */
+
+void
+i386_dr_low_set_addr (int i, CORE_ADDR addr)
+{
+ if (i < 0 || i > 3)
+ return;
+ debug_reg_state.dr_mirror[i] = (unsigned) addr;
+ debug_registers_changed = 1;
+ debug_registers_used = 1;
+}
+
+/* Pass the value VAL to the inferior in the DR7 debug control register.
+ Here we just store the address in D_REGS, the watchpoint
+ will be actually set up in windows_wait. */
+
+void
+i386_dr_low_set_control (unsigned val)
+{
+ debug_reg_state.dr_control_mirror = val;
+ debug_registers_changed = 1;
+ debug_registers_used = 1;
+}
+
+/* Get the value of the DR6 debug status register from the inferior.
+ Here we just return the value stored in dr[6]
+ by the last call to thread_rec for current_event.dwThreadId id. */
+
+unsigned
+i386_dr_low_get_status (void)
+{
+ return debug_reg_state.dr_status_mirror;
+}
+
+/* Watchpoint support. */
+
+static int
+i386_insert_watchpoint (char type, CORE_ADDR addr, int len)
+{
+ return i386_low_insert_watchpoint (&debug_reg_state, type, addr, len);
+}
+
+static int
+i386_remove_watchpoint (char type, CORE_ADDR addr, int len)
+{
+ return i386_low_remove_watchpoint (&debug_reg_state, type, addr, len);
+}
+
+static int
+i386_stopped_by_watchpoint ()
+{
+ return i386_low_stopped_by_watchpoint (&debug_reg_state);
+}
+
+static CORE_ADDR
+i386_stopped_data_address ()
+{
+ return i386_low_stopped_data_address (&debug_reg_state);
+}
+
static void
i386_initial_stuff (void)
{
- memset (&dr, 0, sizeof (dr));
+ memset (&debug_reg_state, 0, sizeof (debug_reg_state));
debug_registers_changed = 0;
debug_registers_used = 0;
}
@@ -55,12 +118,12 @@ i386_get_thread_context (win32_thread_in
if (th->tid == current_event->dwThreadId)
{
/* Copy dr values from the current thread. */
- dr[0] = th->context.Dr0;
- dr[1] = th->context.Dr1;
- dr[2] = th->context.Dr2;
- dr[3] = th->context.Dr3;
- dr[6] = th->context.Dr6;
- dr[7] = th->context.Dr7;
+ debug_reg_state.dr_mirror[0] = th->context.Dr0;
+ debug_reg_state.dr_mirror[1] = th->context.Dr1;
+ debug_reg_state.dr_mirror[2] = th->context.Dr2;
+ debug_reg_state.dr_mirror[3] = th->context.Dr3;
+ debug_reg_state.dr_status_mirror = th->context.Dr6;
+ debug_reg_state.dr_control_mirror = th->context.Dr7;
}
}
@@ -69,13 +132,13 @@ i386_set_thread_context (win32_thread_in
{
if (debug_registers_changed)
{
- th->context.Dr0 = dr[0];
- th->context.Dr1 = dr[1];
- th->context.Dr2 = dr[2];
- th->context.Dr3 = dr[3];
- /* th->context.Dr6 = dr[6];
+ th->context.Dr0 = debug_reg_state.dr_mirror[0];
+ th->context.Dr1 = debug_reg_state.dr_mirror[1];
+ th->context.Dr2 = debug_reg_state.dr_mirror[2];
+ th->context.Dr3 = debug_reg_state.dr_mirror[3];
+ /* th->context.Dr6 = debug_reg_state.dr_status_mirror;
FIXME: should we set dr6 also ?? */
- th->context.Dr7 = dr[7];
+ th->context.Dr7 = debug_reg_state.dr_control_mirror;
}
SetThreadContext (th->h, &th->context);
@@ -90,14 +153,14 @@ i386_thread_added (win32_thread_info *th
th->context.ContextFlags = CONTEXT_DEBUG_REGISTERS;
GetThreadContext (th->h, &th->context);
- th->context.Dr0 = dr[0];
- th->context.Dr1 = dr[1];
- th->context.Dr2 = dr[2];
- th->context.Dr3 = dr[3];
- /* th->context.Dr6 = dr[6];
+ th->context.Dr0 = debug_reg_state.dr_mirror[0];
+ th->context.Dr1 = debug_reg_state.dr_mirror[1];
+ th->context.Dr2 = debug_reg_state.dr_mirror[2];
+ th->context.Dr3 = debug_reg_state.dr_mirror[3];
+ /* th->context.Dr6 = debug_reg_state.dr_status_mirror;
FIXME: should we set dr6 also ?? */
- th->context.Dr7 = dr[7];
-
+ th->context.Dr7 = debug_reg_state.dr_control_mirror;
+
SetThreadContext (th->h, &th->context);
th->context.ContextFlags = 0;
}
@@ -205,4 +268,8 @@ struct win32_target_ops the_low_target =
i386_single_step,
NULL, /* breakpoint */
0, /* breakpoint_len */
+ i386_insert_watchpoint,
+ i386_remove_watchpoint,
+ i386_stopped_by_watchpoint,
+ i386_stopped_data_address
};
> -----Message d'origine-----
> De : Doug Evans [mailto:dje@google.com]
> Envoyé : Thursday, April 30, 2009 9:19 AM
> À : gdb-patches@sourceware.org; muller@ics.u-strasbg.fr
> Objet : [RFA] i386/amd64 h/w watchpoints in gdbserver
>
> Hi.
>
> I took Pierre's patch here
> http://sourceware.org/ml/gdb-patches/2009-02/msg00206.html
>
> and added support for {i386,amd64}-linux.
> Pierre, I _think_ I didn't break win32 support, but it is different
> than what you originally wrote. Can you test it?
>
> This patch assumes the gdbserver memory leak fix has been applied:
> http://sourceware.org/ml/gdb-patches/2009-04/msg00803.html
>
>
> 2009-04-29 Pierre Muller <muller@ics.u-strasbg.fr>
> Doug Evans <dje@google.com>
>
> * Makefile.in (SFILES): Add i386-low.c
> (i386_low_h): Define.
> (i386-low.o): Add dependencies.
> (linux-i386-low.o): Add i386-low.h dependency.
> (linux-x86-64-low.o): Ditto.
> (win32-i386-low.o): Ditto.
> * i386-low.c: New file.
> * i386-low.h: New file.
> * configure.srv (i[34567]86-*-cygwin*): Add i386-low.o to
> srv_tgtobj.
> (i[34567]86-*-linux*, i[34567]86-*-mingw*, x86_64-*-linux*):
> Ditto.
> * linux-i386-low.c: Include stddef.h, i386-low.h.
> (arch_process_info): New struct.
> (i386_linux_dr_get, i386_linux_dr_set): New functions.
> (i386_dr_low_set_addr, i386_dr_low_set_control): New functions.
> (i386_dr_low_get_status): New function.
> (i386_insert_watchpoint, i386_remove_watchpoint): New functions.
> (i386_stopped_by_watchpoint, i386_stopped_data_address): New
> functions.
> (i386_linux_new_process, i386_linux_new_thread): New functions.
> (the_low_target): Add entries for insert_watchpoint,
> remove_watchpoint,
> stopped_by_watchpoint, stopped_data_address, new_process,
> new_thread.
> * linux-low.c (linux_add_process): Initialize arch_private.
> (linux_remove_process): Free arch_private.
> (notify_low_target_new_thread): New function.
> (handle_extended_wait): Call it.
> (linux_attach_lwp_1, linux_wait_1): Ditto.
> (linux_insert_watchpoint): Update call to
> the_low_target.insert_watchpoint.
> (linux_remove_watchpoint): Update call to
> the_low_target.remove_watchpoint.
> (linux_stopped_by_watchpoint): Update call to
> the_low_target.stopped_by_watchpoint.
> (linux_stopped_data_address): Update call to
> the_low_target.stopped_data_address.
> * linux-low.h (process_info_private): New member arch_private.
> (linux_target_ops): Add arch_private parameter to
> insert_watchpoint,
> remove_watchpoint, stopped_by_watchpoint, stopped_data_address.
> New members new_process, new_thread.
> (ptid_of, PIDGET, TIDGET): New macros.
> * linux-x86-64-low.c: Include stddef.h, i386-low.h.
> (arch_process_info): New struct.
> (x86_64_linux_dr_get, x86_64_linux_dr_set): New functions.
> (i386_dr_low_set_addr, i386_dr_low_set_control): New functions.
> (i386_dr_low_get_status): New function.
> (x86_64_insert_watchpoint, x86_64_remove_watchpoint): New
> functions.
> (x86_64_stopped_by_watchpoint): New function.
> (x86_64_stopped_data_address): New function.
> (x86_64_linux_new_process, x86_64_linux_new_thread): New
> functions.
> (the_low_target): Add entries for insert_watchpoint,
> remove_watchpoint,
> stopped_by_watchpoint, stopped_data_address, new_process,
> new_thread.
> * server.h (paddr): Declare.
> * utils.c (NUMCELLS, CELLSIZE): New macros.
> (get_sell, xsnprintf, paddr): New functions.
> * win32-arm-low.c (the_low_target): Add entries for
> insert_watchpoint,
> remove_watchpoint, stopped_by_watchpoint, stopped_data_address.
> * win32-i386-low.c: Include i386-low.h.
> (i386_dr_low_set_addr, i386_dr_low_set_control): New functions.
> (i386_dr_low_get_status): New function.
> (the_low_target): Add entries for insert_watchpoint,
> remove_watchpoint, stopped_by_watchpoint, stopped_data_address.
> * win32-low.c (win32_insert_watchpoint): New function.
> (win32_remove_watchpoint): New function.
> (win32_stopped_by_watchpoint): New function.
> (win32_stopped_data_address): New function.
> (win32_target_ops): Add entries for insert_watchpoint,
> remove_watchpoint, stopped_by_watchpoint, stopped_data_address.
> * win32-low.h (win32_target_ops): New members insert_watchpoint,
> remove_watchpoint, stopped_by_watchpoint, stopped_data_address.
>
> Index: Makefile.in
> ===================================================================
> RCS file: /cvs/src/src/gdb/gdbserver/Makefile.in,v
> retrieving revision 1.73
> diff -u -p -r1.73 Makefile.in
> --- Makefile.in 1 Apr 2009 22:48:05 -0000 1.73
> +++ Makefile.in 30 Apr 2009 01:23:29 -0000
> @@ -104,7 +104,7 @@ SFILES= $(srcdir)/gdbreplay.c $(srcdir)/
> $(srcdir)/thread-db.c $(srcdir)/utils.c \
> $(srcdir)/linux-arm-low.c $(srcdir)/linux-cris-low.c \
> $(srcdir)/linux-crisv32-low.c $(srcdir)/linux-i386-low.c \
> - $(srcdir)/i387-fp.c \
> + ${srcdir}/i386-low.c $(srcdir)/i387-fp.c \
> $(srcdir)/linux-ia64-low.c $(srcdir)/linux-low.c \
> $(srcdir)/linux-m32r-low.c \
> $(srcdir)/linux-m68k-low.c $(srcdir)/linux-mips-low.c \
> @@ -287,6 +287,10 @@ signals.o: ../common/signals.c $(server_
> memmem.o: ../gnulib/memmem.c
> $(CC) -o memmem.o -c $(CPPFLAGS) $(INTERNAL_CFLAGS) $<
>
> +i386_low_h = $(srcdir)/i386-low.h
> +
> +i386-low.o: i386-low.c $(i386_low_h) $(server_h) $(target_h)
> +
> i387-fp.o: i387-fp.c $(server_h)
>
> linux-low.o: linux-low.c $(linux_low_h) $(server_h)
> @@ -297,7 +301,7 @@ linux-arm-low.o: linux-arm-low.c $(linux
> linux-cris-low.o: linux-cris-low.c $(linux_low_h) $(server_h)
> linux-crisv32-low.o: linux-crisv32-low.c $(linux_low_h) $(server_h)
> linux-i386-low.o: linux-i386-low.c $(linux_low_h) $(server_h) \
> - $(gdb_proc_service_h)
> + $(gdb_proc_service_h) $(i386_low_h)
> linux-ia64-low.o: linux-ia64-low.c $(linux_low_h) $(server_h)
> linux-m32r-low.o: linux-m32r-low.c $(linux_low_h) $(server_h)
> linux-mips-low.o: linux-mips-low.c $(linux_low_h) $(server_h) \
> @@ -306,7 +310,7 @@ linux-ppc-low.o: linux-ppc-low.c $(linux
> linux-s390-low.o: linux-s390-low.c $(linux_low_h) $(server_h)
> linux-sh-low.o: linux-sh-low.c $(linux_low_h) $(server_h)
> linux-x86-64-low.o: linux-x86-64-low.c $(linux_low_h) $(server_h) \
> - $(gdb_proc_service_h)
> + $(gdb_proc_service_h) $(i386_low_h)
> linux-xtensa-low.o: linux-xtensa-low.c xtensa-xtregs.c $(linux_low_h)
> $(server_h)
>
> win32_low_h = $(srcdir)/win32-low.h
> @@ -314,7 +318,7 @@ win32_low_h = $(srcdir)/win32-low.h
> win32-low.o: win32-low.c $(win32_low_h) $(server_h) $(regdef_h)
> $(regcache_h)
>
> win32-arm-low.o: win32-arm-low.c $(win32_low_h) $(server_h)
> -win32-i386-low.o: win32-i386-low.c $(win32_low_h) $(server_h)
> +win32-i386-low.o: win32-i386-low.c $(win32_low_h) $(server_h)
> $(i386_low_h)
>
> spu-low.o: spu-low.c $(server_h)
>
> Index: configure.srv
> ===================================================================
> RCS file: /cvs/src/src/gdb/gdbserver/configure.srv,v
> retrieving revision 1.40
> diff -u -p -r1.40 configure.srv
> --- configure.srv 19 Apr 2009 17:54:52 -0000 1.40
> +++ configure.srv 30 Apr 2009 01:23:29 -0000
> @@ -53,10 +53,10 @@ case "${target}" in
> srv_linux_thread_db=yes
> ;;
> i[34567]86-*-cygwin*) srv_regobj=reg-i386.o
> - srv_tgtobj="win32-low.o win32-i386-low.o"
> + srv_tgtobj="i386-low.o win32-low.o win32-i386-low.o"
> ;;
> i[34567]86-*-linux*) srv_regobj=reg-i386-linux.o
> - srv_tgtobj="linux-low.o linux-i386-low.o i387-fp.o"
> + srv_tgtobj="linux-low.o linux-i386-low.o i386-low.o
> i387-fp.o"
> srv_linux_usrregs=yes
> srv_linux_regsets=yes
> srv_linux_thread_db=yes
> @@ -71,7 +71,7 @@ case "${target}" in
> srv_mingwce=yes
> ;;
> i[34567]86-*-mingw*) srv_regobj=reg-i386.o
> - srv_tgtobj="win32-low.o win32-i386-low.o"
> + srv_tgtobj="i386-low.o win32-low.o win32-i386-low.o"
> srv_mingw=yes
> ;;
> ia64-*-linux*) srv_regobj=reg-ia64.o
> @@ -170,7 +170,7 @@ case "${target}" in
> srv_tgtobj="spu-low.o"
> ;;
> x86_64-*-linux*) srv_regobj=reg-x86-64-linux.o
> - srv_tgtobj="linux-low.o linux-x86-64-low.o
i387-fp.o"
> + srv_tgtobj="linux-low.o linux-x86-64-low.o
i386-low.o
> i387-fp.o"
> srv_linux_regsets=yes
> srv_linux_thread_db=yes
> ;;
> Index: i386-low.c
> ===================================================================
> RCS file: i386-low.c
> diff -N i386-low.c
> --- /dev/null 1 Jan 1970 00:00:00 -0000
> +++ i386-low.c 30 Apr 2009 01:23:29 -0000
> @@ -0,0 +1,667 @@
> +/* Debug register code for the i386.
> +
> + Copyright (C) 2009
> + Free Software Foundation, Inc.
> +
> + This file is part of GDB.
> +
> + This program is free software; you can redistribute it and/or
> modify
> + it under the terms of the GNU General Public License as published
> by
> + the Free Software Foundation; either version 3 of the License, or
> + (at your option) any later version.
> +
> + This program is distributed in the hope that it will be useful,
> + but WITHOUT ANY WARRANTY; without even the implied warranty of
> + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
> + GNU General Public License for more details.
> +
> + You should have received a copy of the GNU General Public License
> + along with this program. If not, see
> <http://www.gnu.org/licenses/>. */
> +
> +#include "server.h"
> +#include "target.h"
> +#include "i386-low.h"
> +
> +/* Support for 8-byte wide hw watchpoints. */
> +#ifndef TARGET_HAS_DR_LEN_8
> +#define TARGET_HAS_DR_LEN_8 (sizeof (long) == 8)
> +#endif
> +
> +enum target_hw_bp_type
> + {
> + hw_write = 0, /* Common HW watchpoint */
> + hw_read = 1, /* Read HW watchpoint */
> + hw_access = 2, /* Access HW watchpoint */
> + hw_execute = 3 /* Execute HW breakpoint */
> + };
> +
> +/* DR7 Debug Control register fields. */
> +
> +/* How many bits to skip in DR7 to get to R/W and LEN fields. */
> +#define DR_CONTROL_SHIFT 16
> +/* How many bits in DR7 per R/W and LEN field for each watchpoint. */
> +#define DR_CONTROL_SIZE 4
> +
> +/* Watchpoint/breakpoint read/write fields in DR7. */
> +#define DR_RW_EXECUTE (0x0) /* Break on instruction execution.
*/
> +#define DR_RW_WRITE (0x1) /* Break on data writes. */
> +#define DR_RW_READ (0x3) /* Break on data reads or writes. */
> +
> +/* This is here for completeness. No platform supports this
> + functionality yet (as of March 2001). Note that the DE flag in the
> + CR4 register needs to be set to support this. */
> +#ifndef DR_RW_IORW
> +#define DR_RW_IORW (0x2) /* Break on I/O reads or writes. */
> +#endif
> +
> +/* Watchpoint/breakpoint length fields in DR7. The 2-bit left shift
> + is so we could OR this with the read/write field defined above. */
> +#define DR_LEN_1 (0x0 << 2) /* 1-byte region watch or breakpoint. */
> +#define DR_LEN_2 (0x1 << 2) /* 2-byte region watch. */
> +#define DR_LEN_4 (0x3 << 2) /* 4-byte region watch. */
> +#define DR_LEN_8 (0x2 << 2) /* 8-byte region watch (AMD64). */
> +
> +/* Local and Global Enable flags in DR7.
> +
> + When the Local Enable flag is set, the breakpoint/watchpoint is
> + enabled only for the current task; the processor automatically
> + clears this flag on every task switch. When the Global Enable flag
> + is set, the breakpoint/watchpoint is enabled for all tasks; the
> + processor never clears this flag.
> +
> + Currently, all watchpoint are locally enabled. If you need to
> + enable them globally, read the comment which pertains to this in
> + i386_insert_aligned_watchpoint below. */
> +#define DR_LOCAL_ENABLE_SHIFT 0 /* Extra shift to the local
> enable bit. */
> +#define DR_GLOBAL_ENABLE_SHIFT 1 /* Extra shift to the global
> enable bit. */
> +#define DR_ENABLE_SIZE 2 /* Two enable bits per debug
register.
> */
> +
> +/* Local and global exact breakpoint enable flags (a.k.a. slowdown
> + flags). These are only required on i386, to allow detection of the
> + exact instruction which caused a watchpoint to break; i486 and
> + later processors do that automatically. We set these flags for
> + backwards compatibility. */
> +#define DR_LOCAL_SLOWDOWN (0x100)
> +#define DR_GLOBAL_SLOWDOWN (0x200)
> +
> +/* Fields reserved by Intel. This includes the GD (General Detect
> + Enable) flag, which causes a debug exception to be generated when a
> + MOV instruction accesses one of the debug registers.
> +
> + FIXME: My Intel manual says we should use 0xF800, not 0xFC00. */
> +#define DR_CONTROL_RESERVED (0xFC00)
> +
> +/* Auxiliary helper macros. */
> +
> +/* A value that masks all fields in DR7 that are reserved by Intel.
> */
> +#define I386_DR_CONTROL_MASK (~DR_CONTROL_RESERVED)
> +
> +/* The I'th debug register is vacant if its Local and Global Enable
> + bits are reset in the Debug Control register. */
> +#define I386_DR_VACANT(state, i) \
> + (((state)->dr_control_mirror & (3 << (DR_ENABLE_SIZE * (i)))) == 0)
> +
> +/* Locally enable the break/watchpoint in the I'th debug register. */
> +#define I386_DR_LOCAL_ENABLE(state, i) \
> + do { \
> + (state)->dr_control_mirror |= \
> + (1 << (DR_LOCAL_ENABLE_SHIFT + DR_ENABLE_SIZE * (i))); \
> + } while (0)
> +
> +/* Globally enable the break/watchpoint in the I'th debug register.
> */
> +#define I386_DR_GLOBAL_ENABLE(state, i) \
> + do { \
> + (state)->dr_control_mirror |= \
> + (1 << (DR_GLOBAL_ENABLE_SHIFT + DR_ENABLE_SIZE * (i))); \
> + } while (0)
> +
> +/* Disable the break/watchpoint in the I'th debug register. */
> +#define I386_DR_DISABLE(state, i) \
> + do { \
> + (state)->dr_control_mirror &= \
> + ~(3 << (DR_ENABLE_SIZE * (i))); \
> + } while (0)
> +
> +/* Set in DR7 the RW and LEN fields for the I'th debug register. */
> +#define I386_DR_SET_RW_LEN(state, i,rwlen) \
> + do { \
> + (state)->dr_control_mirror &= \
> + ~(0x0f << (DR_CONTROL_SHIFT+DR_CONTROL_SIZE*(i))); \
> + (state)->dr_control_mirror |= \
> + ((rwlen) << (DR_CONTROL_SHIFT+DR_CONTROL_SIZE*(i))); \
> + } while (0)
> +
> +/* Get from DR7 the RW and LEN fields for the I'th debug register. */
> +#define I386_DR_GET_RW_LEN(state, i) \
> + (((state)->dr_control_mirror >> (DR_CONTROL_SHIFT + DR_CONTROL_SIZE
> * (i))) & 0x0f)
> +
> +/* Did the watchpoint whose address is in the I'th register break? */
> +#define I386_DR_WATCH_HIT(state,i) ((state)->dr_status_mirror & (1 <<
> (i)))
> +
> +/* A macro to loop over all debug registers. */
> +#define ALL_DEBUG_REGISTERS(i) for (i = 0; i < DR_NADDR; i++)
> +
> +/* Whether or not to print the mirrored debug registers. */
> +static int maint_show_dr = 0;
> +
> +/* Types of operations supported by i386_handle_nonaligned_watchpoint.
> */
> +typedef enum { WP_INSERT, WP_REMOVE, WP_COUNT } i386_wp_op_t;
> +
> +/* Internal functions. */
> +
> +/* Return the value of a 4-bit field for DR7 suitable for watching a
> + region of LEN bytes for accesses of type TYPE. LEN is assumed to
> + have the value of 1, 2, or 4. */
> +static unsigned i386_length_and_rw_bits (int len, enum
> target_hw_bp_type type);
> +
> +/* Insert a watchpoint at address ADDR, which is assumed to be aligned
> + according to the length of the region to watch. LEN_RW_BITS is the
> + value of the bit-field from DR7 which describes the length and
> + access type of the region to be watched by this watchpoint. Return
> + 0 on success, -1 on failure. */
> +static int i386_insert_aligned_watchpoint (struct i386_debug_reg_state
> *state,
> + CORE_ADDR addr,
> + unsigned len_rw_bits);
> +
> +/* Remove a watchpoint at address ADDR, which is assumed to be aligned
> + according to the length of the region to watch. LEN_RW_BITS is the
> + value of the bits from DR7 which describes the length and access
> + type of the region watched by this watchpoint. Return 0 on
> + success, -1 on failure. */
> +static int i386_remove_aligned_watchpoint (struct i386_debug_reg_state
> *state,
> + CORE_ADDR addr,
> + unsigned len_rw_bits);
> +
> +/* Insert or remove a (possibly non-aligned) watchpoint, or count the
> + number of debug registers required to watch a region at address
> + ADDR whose length is LEN for accesses of type TYPE. Return 0 on
> + successful insertion or removal, a positive number when queried
> + about the number of registers, or -1 on failure. If WHAT is not a
> + valid value, bombs through internal_error. */
> +static int i386_handle_nonaligned_watchpoint (struct
> i386_debug_reg_state *state,
> + i386_wp_op_t what,
> + CORE_ADDR addr, int len,
> + enum target_hw_bp_type type);
> +
> +/* Implementation. */
> +
> +/* Clear the reference counts and forget everything we knew about the
> + debug registers. */
> +
> +void
> +i386_low_cleanup_dregs (struct i386_debug_reg_state *state)
> +{
> + int i;
> +
> + ALL_DEBUG_REGISTERS(i)
> + {
> + state->dr_mirror[i] = 0;
> + state->dr_ref_count[i] = 0;
> + }
> + state->dr_control_mirror = 0;
> + state->dr_status_mirror = 0;
> +}
> +
> +/* Print the values of the mirrored debug registers. This is called
> + when maint_show_dr is non-zero. To set that up, type "maint
> + show-debug-regs" at GDB's prompt. */
> +
> +static void
> +i386_show_dr (struct i386_debug_reg_state *state,
> + const char *func, CORE_ADDR addr,
> + int len, enum target_hw_bp_type type)
> +{
> + int i;
> +
> + printf (func);
> + if (addr || len)
> + printf (" (addr=%lx, len=%d, type=%s)",
> + (unsigned long) addr, len,
> + type == hw_write ? "data-write"
> + : (type == hw_read ? "data-read"
> + : (type == hw_access ? "data-read/write"
> + : (type == hw_execute ? "instruction-execute"
> + /* FIXME: if/when I/O read/write
> + watchpoints are supported, add them
> + here. */
> + : "??unknown??"))));
> + printf (":\n");
> + printf ("\tCONTROL (DR7): %08x STATUS (DR6): %08x\n",
> + state->dr_control_mirror, state->dr_status_mirror);
> + ALL_DEBUG_REGISTERS (i)
> + {
> + printf ("\
> +\tDR%d: addr=0x%s, ref.count=%d DR%d: addr=0x%s, ref.count=%d\n",
> + i, paddr (state->dr_mirror[i]), state-
> >dr_ref_count[i],
> + i+1, paddr (state->dr_mirror[i+1]), state-
> >dr_ref_count[i+1]);
> + i++;
> + }
> +}
> +
> +/* Return the value of a 4-bit field for DR7 suitable for watching a
> + region of LEN bytes for accesses of type TYPE. LEN is assumed to
> + have the value of 1, 2, or 4. */
> +
> +static unsigned
> +i386_length_and_rw_bits (int len, enum target_hw_bp_type type)
> +{
> + unsigned rw;
> +
> + switch (type)
> + {
> + case hw_execute:
> + rw = DR_RW_EXECUTE;
> + break;
> + case hw_write:
> + rw = DR_RW_WRITE;
> + break;
> + case hw_read:
> + /* The i386 doesn't support data-read watchpoints. */
> + case hw_access:
> + rw = DR_RW_READ;
> + break;
> +#if 0
> + /* Not yet supported. */
> + case hw_io_access:
> + rw = DR_RW_IORW;
> + break;
> +#endif
> + default:
> + error ("\
> +Invalid hardware breakpoint type %d in i386_length_and_rw_bits.\n",
> + (int) type);
> + }
> +
> + switch (len)
> + {
> + case 1:
> + return (DR_LEN_1 | rw);
> + case 2:
> + return (DR_LEN_2 | rw);
> + case 4:
> + return (DR_LEN_4 | rw);
> + case 8:
> + if (TARGET_HAS_DR_LEN_8)
> + return (DR_LEN_8 | rw);
> + default:
> + error ("\
> +Invalid hardware breakpoint length %d in i386_length_and_rw_bits.\n",
> len);
> + }
> +}
> +
> +/* Insert a watchpoint at address ADDR, which is assumed to be aligned
> + according to the length of the region to watch. LEN_RW_BITS is the
> + value of the bits from DR7 which describes the length and access
> + type of the region to be watched by this watchpoint. Return 0 on
> + success, -1 on failure. */
> +
> +static int
> +i386_insert_aligned_watchpoint (struct i386_debug_reg_state *state,
> + CORE_ADDR addr, unsigned len_rw_bits)
> +{
> + int i;
> +
> + /* First, look for an occupied debug register with the same address
> + and the same RW and LEN definitions. If we find one, we can
> + reuse it for this watchpoint as well (and save a register). */
> + ALL_DEBUG_REGISTERS(i)
> + {
> + if (!I386_DR_VACANT (state, i)
> + && state->dr_mirror[i] == addr
> + && I386_DR_GET_RW_LEN (state, i) == len_rw_bits)
> + {
> + state->dr_ref_count[i]++;
> + return 0;
> + }
> + }
> +
> + /* Next, look for a vacant debug register. */
> + ALL_DEBUG_REGISTERS(i)
> + {
> + if (I386_DR_VACANT (state, i))
> + break;
> + }
> +
> + /* No more debug registers! */
> + if (i >= DR_NADDR)
> + return -1;
> +
> + /* Now set up the register I to watch our region. */
> +
> + /* Record the info in our local mirrored array. */
> + state->dr_mirror[i] = addr;
> + state->dr_ref_count[i] = 1;
> + I386_DR_SET_RW_LEN (state, i, len_rw_bits);
> + /* Note: we only enable the watchpoint locally, i.e. in the current
> + task. Currently, no i386 target allows or supports global
> + watchpoints; however, if any target would want that in the
> + future, GDB should probably provide a command to control whether
> + to enable watchpoints globally or locally, and the code below
> + should use global or local enable and slow-down flags as
> + appropriate. */
> + I386_DR_LOCAL_ENABLE (state, i);
> + state->dr_control_mirror |= DR_LOCAL_SLOWDOWN;
> + state->dr_control_mirror &= I386_DR_CONTROL_MASK;
> +
> + /* Finally, actually pass the info to the inferior. */
> + i386_dr_low_set_addr (i, addr);
> + i386_dr_low_set_control (state->dr_control_mirror);
> +
> + return 0;
> +}
> +
> +/* Reset a watched address for debug reg DR.
> + All implementations just do foo_set_addr (addr, 0), so this is a
> wrapper
> + around foo_set_addr to maintain the concept that this is a reset.
> */
> +
> +static void
> +i386_dr_low_reset_addr (int dr)
> +{
> + i386_dr_low_set_addr (dr, 0);
> +}
> +
> +/* Remove a watchpoint at address ADDR, which is assumed to be aligned
> + according to the length of the region to watch. LEN_RW_BITS is the
> + value of the bits from DR7 which describes the length and access
> + type of the region watched by this watchpoint. Return 0 on
> + success, -1 on failure. */
> +
> +static int
> +i386_remove_aligned_watchpoint (struct i386_debug_reg_state *state,
> + CORE_ADDR addr, unsigned len_rw_bits)
> +{
> + int i, retval = -1;
> +
> + ALL_DEBUG_REGISTERS(i)
> + {
> + if (!I386_DR_VACANT (state, i)
> + && state->dr_mirror[i] == addr
> + && I386_DR_GET_RW_LEN (state, i) == len_rw_bits)
> + {
> + if (--state->dr_ref_count[i] == 0) /* no longer in use? */
> + {
> + /* Reset our mirror. */
> + state->dr_mirror[i] = 0;
> + I386_DR_DISABLE (state, i);
> + /* Reset it in the inferior. */
> + i386_dr_low_set_control (state->dr_control_mirror);
> + i386_dr_low_reset_addr (i);
> + }
> + retval = 0;
> + }
> + }
> +
> + return retval;
> +}
> +
> +/* Insert or remove a (possibly non-aligned) watchpoint, or count the
> + number of debug registers required to watch a region at address
> + ADDR whose length is LEN for accesses of type TYPE. Return 0 on
> + successful insertion or removal, a positive number when queried
> + about the number of registers, or -1 on failure. If WHAT is not a
> + valid value, bombs through internal_error. */
> +
> +static int
> +i386_handle_nonaligned_watchpoint (struct i386_debug_reg_state *state,
> + i386_wp_op_t what, CORE_ADDR addr, int
len,
> + enum target_hw_bp_type type)
> +{
> + int retval = 0, status = 0;
> + int max_wp_len = TARGET_HAS_DR_LEN_8 ? 8 : 4;
> +
> + static int size_try_array[8][8] =
> + {
> + {1, 1, 1, 1, 1, 1, 1, 1}, /* Trying size one. */
> + {2, 1, 2, 1, 2, 1, 2, 1}, /* Trying size two. */
> + {2, 1, 2, 1, 2, 1, 2, 1}, /* Trying size three. */
> + {4, 1, 2, 1, 4, 1, 2, 1}, /* Trying size four. */
> + {4, 1, 2, 1, 4, 1, 2, 1}, /* Trying size five. */
> + {4, 1, 2, 1, 4, 1, 2, 1}, /* Trying size six. */
> + {4, 1, 2, 1, 4, 1, 2, 1}, /* Trying size seven. */
> + {8, 1, 2, 1, 4, 1, 2, 1}, /* Trying size eight. */
> + };
> +
> + while (len > 0)
> + {
> + int align = addr % max_wp_len;
> + /* Four (eight on AMD64) is the maximum length a debug register
> + can watch. */
> + int try = (len > max_wp_len ? (max_wp_len - 1) : len - 1);
> + int size = size_try_array[try][align];
> +
> + if (what == WP_COUNT)
> + {
> + /* size_try_array[] is defined such that each iteration
> + through the loop is guaranteed to produce an address and a
> + size that can be watched with a single debug register.
> + Thus, for counting the registers required to watch a
> + region, we simply need to increment the count on each
> + iteration. */
> + retval++;
> + }
> + else
> + {
> + unsigned len_rw = i386_length_and_rw_bits (size, type);
> +
> + if (what == WP_INSERT)
> + status = i386_insert_aligned_watchpoint (state, addr,
> len_rw);
> + else if (what == WP_REMOVE)
> + status = i386_remove_aligned_watchpoint (state, addr,
> len_rw);
> +#if 0
> + else
> + internal_error (__FILE__, __LINE__, _("\
> +Invalid value %d of operation in
> i386_handle_nonaligned_watchpoint.\n"),
> + (int)what);
> +#endif
> + /* We keep the loop going even after a failure, because some
> + of the other aligned watchpoints might still succeed
> + (e.g. if they watch addresses that are already watched,
> + in which case we just increment the reference counts of
> + occupied debug registers). If we break out of the loop
> + too early, we could cause those addresses watched by
> + other watchpoints to be disabled when breakpoint.c reacts
> + to our failure to insert this watchpoint and tries to
> + remove it. */
> + if (status)
> + retval = status;
> + }
> +
> + addr += size;
> + len -= size;
> + }
> +
> + return retval;
> +}
> +
> +#define Z_PACKET_WRITE_WP '2'
> +#define Z_PACKET_READ_WP '3'
> +#define Z_PACKET_ACCESS_WP '4'
> +
> +static int
> +Z_packet_to_hw_type (char type)
> +{
> + switch (type)
> + {
> + case Z_PACKET_WRITE_WP: return hw_write;
> + case Z_PACKET_READ_WP: return hw_read;
> + case Z_PACKET_ACCESS_WP: return hw_access;
> + default:
> + error ("Z_packet_to_hw_type: bad watchpoint type %c", type);
> + }
> +}
> +
> +/* Insert a watchpoint to watch a memory region which starts at
> + address ADDR and whose length is LEN bytes. Watch memory accesses
> + of the type TYPE_FROM_PACKET. Return 0 on success, -1 on failure.
> */
> +
> +int
> +i386_low_insert_watchpoint (struct i386_debug_reg_state *state,
> + char type_from_packet, CORE_ADDR addr, int len)
> +{
> + int retval;
> + int type = Z_packet_to_hw_type (type_from_packet);
> +
> + if (((len != 1 && len !=2 && len !=4) && !(TARGET_HAS_DR_LEN_8 &&
> len == 8))
> + || addr % len != 0)
> + {
> + retval = i386_handle_nonaligned_watchpoint (state, WP_INSERT,
> + addr, len, type);
> + }
> + else
> + {
> + unsigned len_rw = i386_length_and_rw_bits (len, type);
> +
> + retval = i386_insert_aligned_watchpoint (state, addr, len_rw);
> + }
> +
> + if (maint_show_dr)
> + i386_show_dr (state, "insert_watchpoint", addr, len, type);
> +
> + return retval;
> +}
> +
> +/* Remove a watchpoint that watched the memory region which starts at
> + address ADDR, whose length is LEN bytes, and for accesses of the
> + type TYPE_FROM_PACKET. Return 0 on success, -1 on failure. */
> +
> +int
> +i386_low_remove_watchpoint (struct i386_debug_reg_state *state,
> + char type_from_packet, CORE_ADDR addr, int len)
> +{
> + int retval;
> + int type = Z_packet_to_hw_type (type_from_packet);
> +
> + if (((len != 1 && len !=2 && len !=4) && !(TARGET_HAS_DR_LEN_8 &&
> len == 8))
> + || addr % len != 0)
> + {
> + retval = i386_handle_nonaligned_watchpoint (state, WP_REMOVE,
> + addr, len, type);
> + }
> + else
> + {
> + unsigned len_rw = i386_length_and_rw_bits (len, type);
> +
> + retval = i386_remove_aligned_watchpoint (state, addr, len_rw);
> + }
> + if (maint_show_dr)
> + i386_show_dr (state, "remove_watchpoint", addr, len, type);
> + return retval;
> +}
> +
> +/* Return non-zero if we can watch a memory region that starts at
> + address ADDR and whose length is LEN bytes. */
> +
> +int
> +i386_low_region_ok_for_watchpoint (struct i386_debug_reg_state *state,
> + CORE_ADDR addr, int len)
> +{
> + int nregs;
> +
> + /* Compute how many aligned watchpoints we would need to cover this
> + region. */
> + nregs = i386_handle_nonaligned_watchpoint (state, WP_COUNT,
> + addr, len, hw_write);
> + return nregs <= DR_NADDR ? 1 : 0;
> +}
> +
> +/* If the inferior has some watchpoint that triggered, set the
> + address associated with that watchpoint and return non-zero.
> + Otherwise, return zero. */
> +
> +CORE_ADDR
> +i386_low_stopped_data_address (struct i386_debug_reg_state *state)
> +{
> + CORE_ADDR addr = 0;
> + int i;
> + int rc = 0;
> +
> + state->dr_status_mirror = i386_dr_low_get_status ();
> +
> + ALL_DEBUG_REGISTERS(i)
> + {
> + if (I386_DR_WATCH_HIT (state, i)
> + /* This second condition makes sure DRi is set up for a data
> + watchpoint, not a hardware breakpoint. The reason is
> + that GDB doesn't call the target_stopped_data_address
> + method except for data watchpoints. In other words, I'm
> + being paranoiac. */
> + && I386_DR_GET_RW_LEN (state, i) != 0)
> + {
> + addr = state->dr_mirror[i];
> + rc = 1;
> + if (maint_show_dr)
> + i386_show_dr (state, "watchpoint_hit", addr, -1, hw_write);
> + }
> + }
> + if (maint_show_dr && addr == 0)
> + i386_show_dr (state, "stopped_data_addr", 0, 0, hw_write);
> +
> + /* NOTE: gdb version checks rc != 0 here. */
> + return addr;
> +}
> +
> +int
> +i386_low_stopped_by_watchpoint (struct i386_debug_reg_state *state)
> +{
> + CORE_ADDR addr = 0;
> + /* NOTE: gdb version passes boolean found/not-found result from
> + i386_stopped_data_address. */
> + addr = i386_low_stopped_data_address (state);
> + return (addr != 0);
> +}
> +
> +/* Support for h/w breakpoints.
> + This support is not currently used, kept for reference. */
> +
> +/* Return non-zero if the inferior has some break/watchpoint that
> + triggered. */
> +
> +int
> +i386_low_stopped_by_hwbp (struct i386_debug_reg_state *state)
> +{
> + int i;
> +
> + state->dr_status_mirror = i386_dr_low_get_status ();
> + if (maint_show_dr)
> + i386_show_dr (state, "stopped_by_hwbp", 0, 0, hw_execute);
> +
> + ALL_DEBUG_REGISTERS(i)
> + {
> + if (I386_DR_WATCH_HIT (state, i))
> + return 1;
> + }
> +
> + return 0;
> +}
> +
> +/* Insert a hardware-assisted breakpoint at ADDR.
> + Return 0 on success, -1 on failure. */
> +
> +int
> +i386_low_insert_hw_breakpoint (struct i386_debug_reg_state *state,
> + CORE_ADDR addr)
> +{
> + unsigned len_rw = i386_length_and_rw_bits (1, hw_execute);
> + int retval = i386_insert_aligned_watchpoint (state, addr, len_rw);
> +
> + if (maint_show_dr)
> + i386_show_dr (state, "insert_hwbp", addr, 1, hw_execute);
> +
> + return retval;
> +}
> +
> +/* Remove a hardware-assisted breakpoint at ADDR.
> + Return 0 on success, -1 on failure. */
> +
> +int
> +i386_low_remove_hw_breakpoint (struct i386_debug_reg_state *state,
> + CORE_ADDR addr)
> +{
> + unsigned len_rw = i386_length_and_rw_bits (1, hw_execute);
> + int retval = i386_remove_aligned_watchpoint (state, addr, len_rw);
> +
> + if (maint_show_dr)
> + i386_show_dr (state, "remove_hwbp", addr, 1, hw_execute);
> +
> + return retval;
> +}
> Index: i386-low.h
> ===================================================================
> RCS file: i386-low.h
> diff -N i386-low.h
> --- /dev/null 1 Jan 1970 00:00:00 -0000
> +++ i386-low.h 30 Apr 2009 01:23:29 -0000
> @@ -0,0 +1,118 @@
> +/* Misc. low level support for i386.
> +
> + Copyright (C) 2009
> + Free Software Foundation, Inc.
> +
> + This file is part of GDB.
> +
> + This program is free software; you can redistribute it and/or
> modify
> + it under the terms of the GNU General Public License as published
> by
> + the Free Software Foundation; either version 3 of the License, or
> + (at your option) any later version.
> +
> + This program is distributed in the hope that it will be useful,
> + but WITHOUT ANY WARRANTY; without even the implied warranty of
> + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
> + GNU General Public License for more details.
> +
> + You should have received a copy of the GNU General Public License
> + along with this program. If not, see
> <http://www.gnu.org/licenses/>. */
> +
> +/* Support for hardware watchpoints and breakpoints using the i386
> + debug registers.
> +
> + This provides several functions for inserting and removing
> + hardware-assisted breakpoints and watchpoints, testing if one or
> + more of the watchpoints triggered and at what address, checking
> + whether a given region can be watched, etc.
> +
> + The functions below implement debug registers sharing by reference
> + counts, and allow to watch regions up to 16 bytes long
> + (32 bytes on 64 bit hosts). */
> +
> +
> +/* Debug registers' indices. */
> +#define DR_FIRSTADDR 0
> +#define DR_LASTADDR 3
> +#define DR_NADDR 4 /* The number of debug address registers. */
> +#define DR_STATUS 6
> +#define DR_CONTROL 7
> +
> +/* Global state needed to track h/w watchpoints. */
> +
> +struct i386_debug_reg_state
> +{
> + /* Mirror the inferior's DRi registers. We keep the status and
> + control registers separated because they don't hold addresses.
> */
> + CORE_ADDR dr_mirror[DR_NADDR];
> + unsigned dr_status_mirror, dr_control_mirror;
> +
> + /* Reference counts for each debug register. */
> + int dr_ref_count[DR_NADDR];
> +};
> +
> +/* Clear the reference counts and forget everything we knew about DRi.
> */
> +extern void i386_low_cleanup_dregs (struct i386_debug_reg_state
> *state);
> +
> +/* Insert a watchpoint to watch a memory region which starts at
> + address ADDR and whose length is LEN bytes. Watch memory accesses
> + of the type TYPE_FROM_PACKET. Return 0 on success, -1 on failure.
> */
> +extern int i386_low_insert_watchpoint (struct i386_debug_reg_state
> *state,
> + char type_from_packet, CORE_ADDR
addr,
> + int len);
> +
> +/* Remove a watchpoint that watched the memory region which starts at
> + address ADDR, whose length is LEN bytes, and for accesses of the
> + type TYPE_FROM_PACKET. Return 0 on success, -1 on failure. */
> +extern int i386_low_remove_watchpoint (struct i386_debug_reg_state
> *state,
> + char type_from_packet, CORE_ADDR
addr,
> + int len);
> +
> +/* Return non-zero if we can watch a memory region that starts at
> + address ADDR and whose length is LEN bytes. */
> +extern int i386_low_region_ok_for_watchpoint (struct
> i386_debug_reg_state *state,
> + CORE_ADDR addr, int len);
> +
> +/* If the inferior has some break/watchpoint that triggered, set
> + the address associated with that break/watchpoint and return
> + true. Otherwise, return false. */
> +extern CORE_ADDR i386_low_stopped_data_address (struct
> i386_debug_reg_state *state);
> +
> +extern int i386_low_stopped_by_watchpoint (struct i386_debug_reg_state
> *state);
> +
> +/* Return non-zero if the inferior has some break/watchpoint that
> + triggered. */
> +extern int i386_low_stopped_by_hwbp (struct i386_debug_reg_state
> *state);
> +
> +/* Insert a hardware-assisted breakpoint at ADDR.
> + Return 0 on success, -1 on failure. */
> +extern int i386_low_insert_hw_breakpoint (struct i386_debug_reg_state
> *state,
> + CORE_ADDR addr);
> +
> +/* Remove a hardware-assisted breakpoint at ADDR.
> + Return 0 on success, -1 on failure. */
> +extern int i386_low_remove_hw_breakpoint (struct i386_debug_reg_state
> *state,
> + CORE_ADDR addr);
> +
> +/* Each target needs to provide several low-level functions
> + that will be called to insert watchpoints and hardware breakpoints
> + into the inferior, remove them, and check their status. These
> + functions are:
> +
> + i386_dr_low_set_control -- set the debug control (DR7)
> + register to a given value
> +
> + i386_dr_low_set_addr -- put an address into one debug
> register
> +
> + i386_dr_low_get_status -- return the value of the debug
> + status (DR6) register.
> +*/
> +
> +/* Pass the address ADDR to the inferior in the I'th debug register.
> */
> +extern void i386_dr_low_set_addr (int i, CORE_ADDR addr);
> +
> +/* Pass the value VAL to the inferior in the DR7 debug control
> register. */
> +extern void i386_dr_low_set_control (unsigned val);
> +
> +/* Get the value of the DR6 debug status register from the inferior.
> */
> +extern unsigned i386_dr_low_get_status (void);
> Index: linux-i386-low.c
> ===================================================================
> RCS file: /cvs/src/src/gdb/gdbserver/linux-i386-low.c,v
> retrieving revision 1.19
> diff -u -p -r1.19 linux-i386-low.c
> --- linux-i386-low.c 22 Mar 2009 23:57:10 -0000 1.19
> +++ linux-i386-low.c 30 Apr 2009 01:23:29 -0000
> @@ -17,9 +17,11 @@
> You should have received a copy of the GNU General Public License
> along with this program. If not, see
> <http://www.gnu.org/licenses/>. */
>
> +#include <stddef.h>
> #include "server.h"
> #include "linux-low.h"
> #include "i387-fp.h"
> +#include "i386-low.h"
>
> #include "gdb_proc_service.h"
>
> @@ -33,10 +35,14 @@
> #define PTRACE_GET_THREAD_AREA 25
> #endif
>
> +struct arch_process_info
> +{
> + struct i386_debug_reg_state debug_reg_state;
> +};
> +
> /* Defined in auto-generated file reg-i386-linux.c. */
> void init_registers_i386_linux (void);
>
> -
> /* This module only supports access to the general purpose registers.
> */
>
> #define i386_num_regs 16
> @@ -187,6 +193,148 @@ i386_breakpoint_at (CORE_ADDR pc)
>
> return 0;
> }
> +
> +/* Support for debug registers. */
> +
> +static unsigned long
> +i386_linux_dr_get (ptid_t ptid, int regnum)
> +{
> + int tid;
> + unsigned long value;
> +
> + tid = TIDGET (ptid);
> + if (tid == 0)
> + tid = PIDGET (ptid);
> +
> + errno = 0;
> + value = ptrace (PTRACE_PEEKUSER, tid,
> + offsetof (struct user, u_debugreg[regnum]), 0);
> + if (errno != 0)
> + error ("Couldn't read debug register");
> +
> + return value;
> +}
> +
> +static void
> +i386_linux_dr_set (ptid_t ptid, int regnum, unsigned long value)
> +{
> + int tid;
> +
> + tid = TIDGET (ptid);
> + if (tid == 0)
> + tid = PIDGET (ptid);
> +
> + errno = 0;
> + ptrace (PTRACE_POKEUSER, tid,
> + offsetof (struct user, u_debugreg[regnum]), value);
> + if (errno != 0)
> + error ("Couldn't write debug register");
> +}
> +
> +/* Pass the address ADDR to the inferior in debug register REGNUM. */
> +
> +void
> +i386_dr_low_set_addr (int regnum, CORE_ADDR addr)
> +{
> + struct inferior_list_entry *lp;
> +
> + if (! (regnum >= 0 && regnum <= DR_LASTADDR - DR_FIRSTADDR))
> + error ("Invalid debug register");
> +
> + for (lp = all_lwps.head; lp; lp = lp->next)
> + {
> + struct lwp_info *lwp = (struct lwp_info *) lp;
> + i386_linux_dr_set (ptid_of (lwp), DR_FIRSTADDR + regnum, addr);
> + }
> +}
> +
> +/* Pass the value VAL to the inferior in the DR7 debug control
> register. */
> +
> +void
> +i386_dr_low_set_control (unsigned control)
> +{
> + struct inferior_list_entry *lp;
> +
> + for (lp = all_lwps.head; lp; lp = lp->next)
> + {
> + struct lwp_info *lwp = (struct lwp_info *) lp;
> + i386_linux_dr_set (ptid_of (lwp), DR_CONTROL, control);
> + }
> +}
> +
> +/* Get the value of the DR6 debug status register from the inferior.
> */
> +
> +unsigned
> +i386_dr_low_get_status (void)
> +{
> + ptid_t inferior_ptid = ptid_of (get_thread_lwp (current_inferior));
> + return i386_linux_dr_get (inferior_ptid, DR_STATUS);
> +}
> +
> +/* Watchpoint support. */
> +
> +static int
> +i386_insert_watchpoint (struct arch_process_info *arch_private,
> + char type, CORE_ADDR addr, int len)
> +{
> + return i386_low_insert_watchpoint (&arch_private->debug_reg_state,
> + type, addr, len);
> +}
> +
> +static int
> +i386_remove_watchpoint (struct arch_process_info *arch_private,
> + char type, CORE_ADDR addr, int len)
> +{
> + return i386_low_remove_watchpoint (&arch_private->debug_reg_state,
> + type, addr, len);
> +}
> +
> +static int
> +i386_stopped_by_watchpoint (struct arch_process_info *arch_private)
> +{
> + return i386_low_stopped_by_watchpoint (&arch_private-
> >debug_reg_state);
> +}
> +
> +static CORE_ADDR
> +i386_stopped_data_address (struct arch_process_info *arch_private)
> +{
> + return i386_low_stopped_data_address (&arch_private-
> >debug_reg_state);
> +}
> +
> +/* Called when a new process is created. */
> +
> +struct arch_process_info *
> +i386_linux_new_process (int pid, int attached)
> +{
> + struct arch_process_info *info = xcalloc (1, sizeof (*info));
> +
> + return info;
> +}
> +
> +/* Called when a new thread is detected.
> + INITIAL is non-zero for the main thread, zero otherwise. */
> +
> +static void
> +i386_linux_new_thread (struct lwp_info *lwp, int initial)
> +{
> + /* The initial thread has debug regs set later during process
> + creation/attaching handling. */
> +
> + if (! initial)
> + {
> + int i;
> + ptid_t ptid = ptid_of (lwp);
> + int pid = PIDGET (ptid);
> + struct process_info *proc = find_process_pid (pid);
> + struct arch_process_info *arch_private = proc->private-
> >arch_private;
> + struct i386_debug_reg_state *state = &arch_private-
> >debug_reg_state;
> +
> + for (i = DR_FIRSTADDR; i <= DR_LASTADDR; i++)
> + i386_linux_dr_set (ptid, i, state->dr_mirror[i]);
> +
> + i386_linux_dr_set (ptid, DR_CONTROL, state->dr_control_mirror);
> + }
> +}
>
> struct linux_target_ops the_low_target = {
> init_registers_i386_linux,
> @@ -201,10 +349,12 @@ struct linux_target_ops the_low_target =
> NULL,
> 1,
> i386_breakpoint_at,
> + i386_insert_watchpoint,
> + i386_remove_watchpoint,
> + i386_stopped_by_watchpoint,
> + i386_stopped_data_address,
> NULL,
> NULL,
> - NULL,
> - NULL,
> - NULL,
> - NULL,
> + i386_linux_new_process,
> + i386_linux_new_thread
> };
> Index: linux-low.c
> ===================================================================
> RCS file: /cvs/src/src/gdb/gdbserver/linux-low.c,v
> retrieving revision 1.97
> diff -u -p -r1.97 linux-low.c
> --- linux-low.c 3 Apr 2009 11:40:02 -0000 1.97
> +++ linux-low.c 30 Apr 2009 06:26:54 -0000
> @@ -120,6 +120,7 @@ static int must_set_ptrace_flags;
> control of gdbserver have the same architecture. */
> static int new_inferior;
>
> +static void notify_low_target_new_thread (struct lwp_info *lwp, int
> initial);
> static void linux_resume_one_lwp (struct inferior_list_entry *entry,
> int step, int signal, siginfo_t *info);
> static void linux_resume (struct thread_resume *resume_info, size_t
> n);
> @@ -179,6 +180,9 @@ linux_add_process (int pid, int attached
> proc = add_process (pid, attached);
> proc->private = xcalloc (1, sizeof (*proc->private));
>
> + if (the_low_target.new_process != NULL)
> + proc->private->arch_private = the_low_target.new_process (pid,
> attached);
> +
> return proc;
> }
>
> @@ -188,6 +192,7 @@ linux_add_process (int pid, int attached
> static void
> linux_remove_process (struct process_info *process)
> {
> + free (process->private->arch_private);
> free (process->private);
> remove_process (process);
> }
> @@ -231,6 +236,7 @@ handle_extended_wait (struct lwp_info *e
> ptid = ptid_build (pid_of (event_child), new_pid, 0);
> new_lwp = (struct lwp_info *) add_lwp (ptid);
> add_thread (ptid, new_lwp);
> + notify_low_target_new_thread (new_lwp, 0);
>
> /* Normally we will get the pending SIGSTOP. But in some cases
> we might get another signal delivered to the group first.
> @@ -313,6 +319,18 @@ add_lwp (ptid_t ptid)
> return lwp;
> }
>
> +/* Notify the backend that we have a new thread, be it the main thread
> + or a later one.
> + INITIAL is non-zero for the main thread, zero otherwise.
> + NOTE: This must be called when the thread is stopped. */
> +
> +static void
> +notify_low_target_new_thread (struct lwp_info *lwp, int initial)
> +{
> + if (the_low_target.new_thread != NULL)
> + the_low_target.new_thread (lwp, initial);
> +}
> +
> /* Start an inferior process and returns its pid.
> ALLARGS is a vector of program-name and args. */
>
> @@ -354,6 +372,8 @@ linux_create_inferior (char *program, ch
> ptid = ptid_build (pid, pid, 0);
> new_lwp = add_lwp (ptid);
> add_thread (ptid, new_lwp);
> + /* We can't call notify_low_target_new_thread there, the thread
> isn't
> + stopped. Piggyback on must_set_ptrace_flags and call it then.
> */
> must_set_ptrace_flags = 1;
>
> return pid;
> @@ -401,6 +421,7 @@ linux_attach_lwp_1 (unsigned long lwpid,
>
> new_lwp = (struct lwp_info *) add_lwp (ptid);
> add_thread (ptid, new_lwp);
> + notify_low_target_new_thread (new_lwp, initial);
>
> /* The next time we wait for this LWP we'll see a SIGSTOP as
> PTRACE_ATTACH
> brings it to a halt.
> @@ -1261,6 +1282,7 @@ retry:
> if (must_set_ptrace_flags)
> {
> ptrace (PTRACE_SETOPTIONS, lwpid_of (lwp), 0,
> PTRACE_O_TRACECLONE);
> + notify_low_target_new_thread (lwp, 1);
> must_set_ptrace_flags = 0;
> }
> /* If we are waiting for a particular child, and it exited,
> @@ -2599,7 +2623,11 @@ static int
> linux_insert_watchpoint (char type, CORE_ADDR addr, int len)
> {
> if (the_low_target.insert_watchpoint != NULL)
> - return the_low_target.insert_watchpoint (type, addr, len);
> + {
> + struct process_info *proc = current_process ();
> + return the_low_target.insert_watchpoint (proc->private-
> >arch_private,
> + type, addr, len);
> + }
> else
> /* Unsupported (see target.h). */
> return 1;
> @@ -2609,7 +2637,11 @@ static int
> linux_remove_watchpoint (char type, CORE_ADDR addr, int len)
> {
> if (the_low_target.remove_watchpoint != NULL)
> - return the_low_target.remove_watchpoint (type, addr, len);
> + {
> + struct process_info *proc = current_process ();
> + return the_low_target.remove_watchpoint (proc->private-
> >arch_private,
> + type, addr, len);
> + }
> else
> /* Unsupported (see target.h). */
> return 1;
> @@ -2619,7 +2651,10 @@ static int
> linux_stopped_by_watchpoint (void)
> {
> if (the_low_target.stopped_by_watchpoint != NULL)
> - return the_low_target.stopped_by_watchpoint ();
> + {
> + struct process_info *proc = current_process ();
> + return the_low_target.stopped_by_watchpoint (proc->private-
> >arch_private);
> + }
> else
> return 0;
> }
> @@ -2628,7 +2663,10 @@ static CORE_ADDR
> linux_stopped_data_address (void)
> {
> if (the_low_target.stopped_data_address != NULL)
> - return the_low_target.stopped_data_address ();
> + {
> + struct process_info *proc = current_process ();
> + return the_low_target.stopped_data_address (proc->private-
> >arch_private);
> + }
> else
> return 0;
> }
> Index: linux-low.h
> ===================================================================
> RCS file: /cvs/src/src/gdb/gdbserver/linux-low.h,v
> retrieving revision 1.28
> diff -u -p -r1.28 linux-low.h
> --- linux-low.h 1 Apr 2009 22:50:24 -0000 1.28
> +++ linux-low.h 30 Apr 2009 01:23:29 -0000
> @@ -54,8 +54,13 @@ struct process_info_private
>
> /* Connection to the libthread_db library. */
> td_thragent_t *thread_agent;
> +
> + /* Target-specific additions. */
> + struct arch_process_info *arch_private;
> };
>
> +struct lwp_info;
> +
> struct linux_target_ops
> {
> /* Architecture-specific setup. */
> @@ -75,26 +80,37 @@ struct linux_target_ops
> int breakpoint_len;
> CORE_ADDR (*breakpoint_reinsert_addr) (void);
>
> -
> int decr_pc_after_break;
> int (*breakpoint_at) (CORE_ADDR pc);
>
> /* Watchpoint related functions. See target.h for comments. */
> - int (*insert_watchpoint) (char type, CORE_ADDR addr, int len);
> - int (*remove_watchpoint) (char type, CORE_ADDR addr, int len);
> - int (*stopped_by_watchpoint) (void);
> - CORE_ADDR (*stopped_data_address) (void);
> + int (*insert_watchpoint) (struct arch_process_info *arch_private,
> + char type, CORE_ADDR addr, int len);
> + int (*remove_watchpoint) (struct arch_process_info *arch_private,
> + char type, CORE_ADDR addr, int len);
> + int (*stopped_by_watchpoint) (struct arch_process_info
> *arch_private);
> + CORE_ADDR (*stopped_data_address) (struct arch_process_info
> *arch_private);
>
> /* Hooks to reformat register data for PEEKUSR/POKEUSR (in
> particular
> for registers smaller than an xfer unit). */
> void (*collect_ptrace_register) (int regno, char *buf);
> void (*supply_ptrace_register) (int regno, const char *buf);
> +
> + /* Hook to call when a new process is created or attached to. */
> + struct arch_process_info * (*new_process) (int pid, int attached);
> +
> + /* Hook to call when a new thread is detected.
> + INITIAL is non-zero for the main thread, zero otherwise. */
> + void (*new_thread) (struct lwp_info *, int initial);
> };
>
> extern struct linux_target_ops the_low_target;
>
> +#define ptid_of(proc) ((proc)->head.id)
> #define pid_of(proc) ptid_get_pid ((proc)->head.id)
> #define lwpid_of(proc) ptid_get_lwp ((proc)->head.id)
> +#define PIDGET(ptid) ptid_get_pid (ptid)
> +#define TIDGET(ptid) ptid_get_lwp (ptid)
>
> #define get_lwp(inf) ((struct lwp_info *)(inf))
> #define get_thread_lwp(thr) (get_lwp (inferior_target_data (thr)))
> Index: linux-x86-64-low.c
> ===================================================================
> RCS file: /cvs/src/src/gdb/gdbserver/linux-x86-64-low.c,v
> retrieving revision 1.22
> diff -u -p -r1.22 linux-x86-64-low.c
> --- linux-x86-64-low.c 22 Mar 2009 23:57:10 -0000 1.22
> +++ linux-x86-64-low.c 30 Apr 2009 01:23:29 -0000
> @@ -18,9 +18,11 @@
> You should have received a copy of the GNU General Public License
> along with this program. If not, see
> <http://www.gnu.org/licenses/>. */
>
> +#include <stddef.h>
> #include "server.h"
> #include "linux-low.h"
> #include "i387-fp.h"
> +#include "i386-low.h"
>
> #include "gdb_proc_service.h"
>
> @@ -45,6 +47,11 @@ void init_registers_x86_64_linux (void);
> #define ARCH_GET_GS 0x1004
> #endif
>
> +struct arch_process_info
> +{
> + struct i386_debug_reg_state debug_reg_state;
> +};
> +
> static int x86_64_regmap[] = {
> RAX * 8, RBX * 8, RCX * 8, RDX * 8,
> RSI * 8, RDI * 8, RBP * 8, RSP * 8,
> @@ -161,6 +168,148 @@ x86_64_breakpoint_at (CORE_ADDR pc)
>
> return 0;
> }
> +
> +/* Support for debug registers. */
> +
> +static unsigned long
> +x86_64_linux_dr_get (ptid_t ptid, int regnum)
> +{
> + int tid;
> + unsigned long value;
> +
> + tid = TIDGET (ptid);
> + if (tid == 0)
> + tid = PIDGET (ptid);
> +
> + errno = 0;
> + value = ptrace (PTRACE_PEEKUSER, tid,
> + offsetof (struct user, u_debugreg[regnum]), 0);
> + if (errno != 0)
> + error ("Couldn't read debug register");
> +
> + return value;
> +}
> +
> +static void
> +x86_64_linux_dr_set (ptid_t ptid, int regnum, unsigned long value)
> +{
> + int tid;
> +
> + tid = TIDGET (ptid);
> + if (tid == 0)
> + tid = PIDGET (ptid);
> +
> + errno = 0;
> + ptrace (PTRACE_POKEUSER, tid,
> + offsetof (struct user, u_debugreg[regnum]), value);
> + if (errno != 0)
> + error ("Couldn't write debug register");
> +}
> +
> +/* Pass the address ADDR to the inferior in debug register REGNUM. */
> +
> +void
> +i386_dr_low_set_addr (int regnum, CORE_ADDR addr)
> +{
> + struct inferior_list_entry *lp;
> +
> + if (! (regnum >= 0 && regnum <= DR_LASTADDR - DR_FIRSTADDR))
> + error ("Invalid debug register");
> +
> + for (lp = all_lwps.head; lp; lp = lp->next)
> + {
> + struct lwp_info *lwp = (struct lwp_info *) lp;
> + x86_64_linux_dr_set (ptid_of (lwp), DR_FIRSTADDR + regnum,
> addr);
> + }
> +}
> +
> +/* Pass the value VAL to the inferior in the DR7 debug control
> register. */
> +
> +void
> +i386_dr_low_set_control (unsigned control)
> +{
> + struct inferior_list_entry *lp;
> +
> + for (lp = all_lwps.head; lp; lp = lp->next)
> + {
> + struct lwp_info *lwp = (struct lwp_info *) lp;
> + x86_64_linux_dr_set (ptid_of (lwp), DR_CONTROL, control);
> + }
> +}
> +
> +/* Get the value of the DR6 debug status register from the inferior.
> */
> +
> +unsigned
> +i386_dr_low_get_status (void)
> +{
> + ptid_t inferior_ptid = ptid_of (get_thread_lwp (current_inferior));
> + return x86_64_linux_dr_get (inferior_ptid, DR_STATUS);
> +}
> +
> +/* Watchpoint support. */
> +
> +static int
> +x86_64_insert_watchpoint (struct arch_process_info *arch_private,
> + char type, CORE_ADDR addr, int len)
> +{
> + return i386_low_insert_watchpoint (&arch_private->debug_reg_state,
> + type, addr, len);
> +}
> +
> +static int
> +x86_64_remove_watchpoint (struct arch_process_info *arch_private,
> + char type, CORE_ADDR addr, int len)
> +{
> + return i386_low_remove_watchpoint (&arch_private->debug_reg_state,
> + type, addr, len);
> +}
> +
> +static int
> +x86_64_stopped_by_watchpoint (struct arch_process_info *arch_private)
> +{
> + return i386_low_stopped_by_watchpoint (&arch_private-
> >debug_reg_state);
> +}
> +
> +static CORE_ADDR
> +x86_64_stopped_data_address (struct arch_process_info *arch_private)
> +{
> + return i386_low_stopped_data_address (&arch_private-
> >debug_reg_state);
> +}
> +
> +/* Called when a new process is created. */
> +
> +struct arch_process_info *
> +x86_64_linux_new_process (int pid, int attached)
> +{
> + struct arch_process_info *info = xcalloc (1, sizeof (*info));
> +
> + return info;
> +}
> +
> +/* Called when a new thread is detected.
> + INITIAL is non-zero for the main thread, zero otherwise. */
> +
> +static void
> +x86_64_linux_new_thread (struct lwp_info *lwp, int initial)
> +{
> + /* The initial thread has debug regs set later during process
> + creation/attaching handling. */
> +
> + if (! initial)
> + {
> + int i;
> + ptid_t ptid = ptid_of (lwp);
> + int pid = PIDGET (ptid);
> + struct process_info *proc = find_process_pid (pid);
> + struct arch_process_info *arch_private = proc->private-
> >arch_private;
> + struct i386_debug_reg_state *state = &arch_private-
> >debug_reg_state;
> +
> + for (i = DR_FIRSTADDR; i <= DR_LASTADDR; i++)
> + x86_64_linux_dr_set (ptid, i, state->dr_mirror[i]);
> +
> + x86_64_linux_dr_set (ptid, DR_CONTROL, state-
> >dr_control_mirror);
> + }
> +}
>
> struct linux_target_ops the_low_target = {
> init_registers_x86_64_linux,
> @@ -175,10 +324,12 @@ struct linux_target_ops the_low_target =
> NULL,
> 1,
> x86_64_breakpoint_at,
> + x86_64_insert_watchpoint,
> + x86_64_remove_watchpoint,
> + x86_64_stopped_by_watchpoint,
> + x86_64_stopped_data_address,
> NULL,
> NULL,
> - NULL,
> - NULL,
> - NULL,
> - NULL,
> + x86_64_linux_new_process,
> + x86_64_linux_new_thread
> };
> Index: server.h
> ===================================================================
> RCS file: /cvs/src/src/gdb/gdbserver/server.h,v
> retrieving revision 1.56
> diff -u -p -r1.56 server.h
> --- server.h 3 Apr 2009 20:15:51 -0000 1.56
> +++ server.h 30 Apr 2009 01:23:29 -0000
> @@ -405,6 +405,7 @@ void perror_with_name (const char *strin
> void error (const char *string,...) ATTR_NORETURN ATTR_FORMAT (printf,
> 1, 2);
> void fatal (const char *string,...) ATTR_NORETURN ATTR_FORMAT (printf,
> 1, 2);
> void warning (const char *string,...) ATTR_FORMAT (printf, 1, 2);
> +char *paddr (CORE_ADDR addr);
>
> /* Maximum number of bytes to read/write at once. The value here
> is chosen to fill up a packet (the headers account for the 32). */
> Index: utils.c
> ===================================================================
> RCS file: /cvs/src/src/gdb/gdbserver/utils.c,v
> retrieving revision 1.18
> diff -u -p -r1.18 utils.c
> --- utils.c 19 Jan 2009 00:16:46 -0000 1.18
> +++ utils.c 30 Apr 2009 01:23:29 -0000
> @@ -170,3 +170,37 @@ warning (const char *string,...)
> fprintf (stderr, "\n");
> va_end (args);
> }
> +
> +/* temporary storage using circular buffer */
> +#define NUMCELLS 4
> +#define CELLSIZE 50
> +static char *
> +get_cell (void)
> +{
> + static char buf[NUMCELLS][CELLSIZE];
> + static int cell = 0;
> + if (++cell >= NUMCELLS)
> + cell = 0;
> + return buf[cell];
> +}
> +
> +static int
> +xsnprintf (char *str, size_t size, const char *format, ...)
> +{
> + va_list args;
> + int ret;
> +
> + va_start (args, format);
> + ret = vsnprintf (str, size, format, args);
> + va_end (args);
> +
> + return ret;
> +}
> +
> +char *
> +paddr (CORE_ADDR addr)
> +{
> + char *str = get_cell ();
> + xsnprintf (str, CELLSIZE, "%lx", (long) addr);
> + return str;
> +}
> Index: win32-arm-low.c
> ===================================================================
> RCS file: /cvs/src/src/gdb/gdbserver/win32-arm-low.c,v
> retrieving revision 1.8
> diff -u -p -r1.8 win32-arm-low.c
> --- win32-arm-low.c 3 Jan 2009 05:57:57 -0000 1.8
> +++ win32-arm-low.c 30 Apr 2009 01:23:29 -0000
> @@ -122,4 +122,9 @@ struct win32_target_ops the_low_target =
> NULL, /* single_step */
> (const unsigned char *) &arm_wince_breakpoint,
> arm_wince_breakpoint_len,
> + /* Watchpoint related functions. See target.h for comments. */
> + NULL, /* insert_watchpoint */
> + NULL, /* remove_watchpoint */
> + NULL, /* stopped_by_watchpoint */
> + NULL /* stopped_data_address */
> };
> Index: win32-i386-low.c
> ===================================================================
> RCS file: /cvs/src/src/gdb/gdbserver/win32-i386-low.c,v
> retrieving revision 1.14
> diff -u -p -r1.14 win32-i386-low.c
> --- win32-i386-low.c 3 Jan 2009 05:57:57 -0000 1.14
> +++ win32-i386-low.c 30 Apr 2009 01:23:29 -0000
> @@ -17,6 +17,7 @@
>
> #include "server.h"
> #include "win32-low.h"
> +#include "i386-low.h"
>
> #define FCS_REGNUM 27
> #define FOP_REGNUM 31
> @@ -31,6 +32,42 @@ static unsigned dr[8];
> static int debug_registers_changed = 0;
> static int debug_registers_used = 0;
>
> +/* Pass the address ADDR to the inferior in the I'th debug register.
> + Here we just store the address in dr array, the registers will be
> + actually set up when windows_continue is called. */
> +
> +void
> +i386_dr_low_set_addr (int i, CORE_ADDR addr)
> +{
> + if (i < 0 || i > 3)
> + return;
> + dr[i] = (unsigned) addr;
> + debug_registers_changed = 1;
> + debug_registers_used = 1;
> +}
> +
> +/* Pass the value VAL to the inferior in the DR7 debug control
> register.
> + Here we just store the address in D_REGS, the watchpoint
> + will be actually set up in windows_wait. */
> +
> +void
> +i386_dr_low_set_control (unsigned val)
> +{
> + dr[7] = val;
> + debug_registers_changed = 1;
> + debug_registers_used = 1;
> +}
> +
> +/* Get the value of the DR6 debug status register from the inferior.
> + Here we just return the value stored in dr[6]
> + by the last call to thread_rec for current_event.dwThreadId id. */
> +
> +unsigned
> +i386_dr_low_get_status (void)
> +{
> + return dr[6];
> +}
> +
> static void
> i386_initial_stuff (void)
> {
> @@ -205,4 +242,8 @@ struct win32_target_ops the_low_target =
> i386_single_step,
> NULL, /* breakpoint */
> 0, /* breakpoint_len */
> + i386_insert_watchpoint,
> + i386_remove_watchpoint,
> + i386_stopped_by_watchpoint,
> + i386_stopped_data_address
> };
> Index: win32-low.c
> ===================================================================
> RCS file: /cvs/src/src/gdb/gdbserver/win32-low.c,v
> retrieving revision 1.35
> diff -u -p -r1.35 win32-low.c
> --- win32-low.c 1 Apr 2009 22:50:24 -0000 1.35
> +++ win32-low.c 30 Apr 2009 01:23:29 -0000
> @@ -228,6 +228,48 @@ child_delete_thread (DWORD pid, DWORD ti
> delete_thread_info (thread);
> }
>
> +/* These watchpoint related wrapper functions simply pass on the
> function call
> + if the target has registered a corresponding function. */
> +
> +static int
> +win32_insert_watchpoint (char type, CORE_ADDR addr, int len)
> +{
> + if (the_low_target.insert_watchpoint != NULL)
> + return the_low_target.insert_watchpoint (type, addr, len);
> + else
> + /* Unsupported (see target.h). */
> + return 1;
> +}
> +
> +static int
> +win32_remove_watchpoint (char type, CORE_ADDR addr, int len)
> +{
> + if (the_low_target.remove_watchpoint != NULL)
> + return the_low_target.remove_watchpoint (type, addr, len);
> + else
> + /* Unsupported (see target.h). */
> + return 1;
> +}
> +
> +static int
> +win32_stopped_by_watchpoint (void)
> +{
> + if (the_low_target.stopped_by_watchpoint != NULL)
> + return the_low_target.stopped_by_watchpoint ();
> + else
> + return 0;
> +}
> +
> +static CORE_ADDR
> +win32_stopped_data_address (void)
> +{
> + if (the_low_target.stopped_data_address != NULL)
> + return the_low_target.stopped_data_address ();
> + else
> + return 0;
> +}
> +
> +
> /* Transfer memory from/to the debugged process. */
> static int
> child_xfer_memory (CORE_ADDR memaddr, char *our, int len,
> @@ -1697,10 +1739,10 @@ static struct target_ops win32_target_op
> NULL,
> win32_request_interrupt,
> NULL,
> - NULL,
> - NULL,
> - NULL,
> - NULL,
> + win32_insert_watchpoint,
> + win32_remove_watchpoint,
> + win32_stopped_by_watchpoint,
> + win32_stopped_data_address,
> NULL,
> NULL,
> NULL,
> Index: win32-low.h
> ===================================================================
> RCS file: /cvs/src/src/gdb/gdbserver/win32-low.h,v
> retrieving revision 1.9
> diff -u -p -r1.9 win32-low.h
> --- win32-low.h 3 Jan 2009 05:57:57 -0000 1.9
> +++ win32-low.h 30 Apr 2009 01:23:29 -0000
> @@ -70,6 +70,13 @@ struct win32_target_ops
>
> const unsigned char *breakpoint;
> int breakpoint_len;
> +
> + /* Watchpoint related functions. See target.h for comments. */
> + int (*insert_watchpoint) (char type, CORE_ADDR addr, int len);
> + int (*remove_watchpoint) (char type, CORE_ADDR addr, int len);
> + int (*stopped_by_watchpoint) (void);
> + CORE_ADDR (*stopped_data_address) (void);
> +
> };
>
> extern struct win32_target_ops the_low_target;
^ permalink raw reply [flat|nested] 18+ messages in thread
* Re: [RFA] i386/amd64 h/w watchpoints in gdbserver
2009-04-30 7:19 [RFA] i386/amd64 h/w watchpoints in gdbserver Doug Evans
2009-05-01 8:10 ` Pierre Muller
@ 2009-05-18 23:11 ` Doug Evans
2009-05-18 23:28 ` Doug Evans
1 sibling, 1 reply; 18+ messages in thread
From: Doug Evans @ 2009-05-18 23:11 UTC (permalink / raw)
To: gdb-patches, muller
Ping.
[for completeness sake, Pierre, I haven't forgotten about win32-i386-low.c. :-)]
What can I do so that we can make some progress here?
On Thu, Apr 30, 2009 at 12:18 AM, Doug Evans <dje@google.com> wrote:
> Hi.
>
> I took Pierre's patch here
> http://sourceware.org/ml/gdb-patches/2009-02/msg00206.html
>
> and added support for {i386,amd64}-linux.
> Pierre, I _think_ I didn't break win32 support, but it is different
> than what you originally wrote. Can you test it?
>
> This patch assumes the gdbserver memory leak fix has been applied:
> http://sourceware.org/ml/gdb-patches/2009-04/msg00803.html
>
>
> 2009-04-29 Pierre Muller <muller@ics.u-strasbg.fr>
> Doug Evans <dje@google.com>
>
> * Makefile.in (SFILES): Add i386-low.c
> (i386_low_h): Define.
> (i386-low.o): Add dependencies.
> (linux-i386-low.o): Add i386-low.h dependency.
> (linux-x86-64-low.o): Ditto.
> (win32-i386-low.o): Ditto.
> * i386-low.c: New file.
> * i386-low.h: New file.
> * configure.srv (i[34567]86-*-cygwin*): Add i386-low.o to srv_tgtobj.
> (i[34567]86-*-linux*, i[34567]86-*-mingw*, x86_64-*-linux*): Ditto.
> * linux-i386-low.c: Include stddef.h, i386-low.h.
> (arch_process_info): New struct.
> (i386_linux_dr_get, i386_linux_dr_set): New functions.
> (i386_dr_low_set_addr, i386_dr_low_set_control): New functions.
> (i386_dr_low_get_status): New function.
> (i386_insert_watchpoint, i386_remove_watchpoint): New functions.
> (i386_stopped_by_watchpoint, i386_stopped_data_address): New functions.
> (i386_linux_new_process, i386_linux_new_thread): New functions.
> (the_low_target): Add entries for insert_watchpoint, remove_watchpoint,
> stopped_by_watchpoint, stopped_data_address, new_process, new_thread.
> * linux-low.c (linux_add_process): Initialize arch_private.
> (linux_remove_process): Free arch_private.
> (notify_low_target_new_thread): New function.
> (handle_extended_wait): Call it.
> (linux_attach_lwp_1, linux_wait_1): Ditto.
> (linux_insert_watchpoint): Update call to
> the_low_target.insert_watchpoint.
> (linux_remove_watchpoint): Update call to
> the_low_target.remove_watchpoint.
> (linux_stopped_by_watchpoint): Update call to
> the_low_target.stopped_by_watchpoint.
> (linux_stopped_data_address): Update call to
> the_low_target.stopped_data_address.
> * linux-low.h (process_info_private): New member arch_private.
> (linux_target_ops): Add arch_private parameter to insert_watchpoint,
> remove_watchpoint, stopped_by_watchpoint, stopped_data_address.
> New members new_process, new_thread.
> (ptid_of, PIDGET, TIDGET): New macros.
> * linux-x86-64-low.c: Include stddef.h, i386-low.h.
> (arch_process_info): New struct.
> (x86_64_linux_dr_get, x86_64_linux_dr_set): New functions.
> (i386_dr_low_set_addr, i386_dr_low_set_control): New functions.
> (i386_dr_low_get_status): New function.
> (x86_64_insert_watchpoint, x86_64_remove_watchpoint): New functions.
> (x86_64_stopped_by_watchpoint): New function.
> (x86_64_stopped_data_address): New function.
> (x86_64_linux_new_process, x86_64_linux_new_thread): New functions.
> (the_low_target): Add entries for insert_watchpoint, remove_watchpoint,
> stopped_by_watchpoint, stopped_data_address, new_process, new_thread.
> * server.h (paddr): Declare.
> * utils.c (NUMCELLS, CELLSIZE): New macros.
> (get_sell, xsnprintf, paddr): New functions.
> * win32-arm-low.c (the_low_target): Add entries for insert_watchpoint,
> remove_watchpoint, stopped_by_watchpoint, stopped_data_address.
> * win32-i386-low.c: Include i386-low.h.
> (i386_dr_low_set_addr, i386_dr_low_set_control): New functions.
> (i386_dr_low_get_status): New function.
> (the_low_target): Add entries for insert_watchpoint,
> remove_watchpoint, stopped_by_watchpoint, stopped_data_address.
> * win32-low.c (win32_insert_watchpoint): New function.
> (win32_remove_watchpoint): New function.
> (win32_stopped_by_watchpoint): New function.
> (win32_stopped_data_address): New function.
> (win32_target_ops): Add entries for insert_watchpoint,
> remove_watchpoint, stopped_by_watchpoint, stopped_data_address.
> * win32-low.h (win32_target_ops): New members insert_watchpoint,
> remove_watchpoint, stopped_by_watchpoint, stopped_data_address.
>
> Index: Makefile.in
> ===================================================================
> RCS file: /cvs/src/src/gdb/gdbserver/Makefile.in,v
> retrieving revision 1.73
> diff -u -p -r1.73 Makefile.in
> --- Makefile.in 1 Apr 2009 22:48:05 -0000 1.73
> +++ Makefile.in 30 Apr 2009 01:23:29 -0000
> @@ -104,7 +104,7 @@ SFILES= $(srcdir)/gdbreplay.c $(srcdir)/
> $(srcdir)/thread-db.c $(srcdir)/utils.c \
> $(srcdir)/linux-arm-low.c $(srcdir)/linux-cris-low.c \
> $(srcdir)/linux-crisv32-low.c $(srcdir)/linux-i386-low.c \
> - $(srcdir)/i387-fp.c \
> + ${srcdir}/i386-low.c $(srcdir)/i387-fp.c \
> $(srcdir)/linux-ia64-low.c $(srcdir)/linux-low.c \
> $(srcdir)/linux-m32r-low.c \
> $(srcdir)/linux-m68k-low.c $(srcdir)/linux-mips-low.c \
> @@ -287,6 +287,10 @@ signals.o: ../common/signals.c $(server_
> memmem.o: ../gnulib/memmem.c
> $(CC) -o memmem.o -c $(CPPFLAGS) $(INTERNAL_CFLAGS) $<
>
> +i386_low_h = $(srcdir)/i386-low.h
> +
> +i386-low.o: i386-low.c $(i386_low_h) $(server_h) $(target_h)
> +
> i387-fp.o: i387-fp.c $(server_h)
>
> linux-low.o: linux-low.c $(linux_low_h) $(server_h)
> @@ -297,7 +301,7 @@ linux-arm-low.o: linux-arm-low.c $(linux
> linux-cris-low.o: linux-cris-low.c $(linux_low_h) $(server_h)
> linux-crisv32-low.o: linux-crisv32-low.c $(linux_low_h) $(server_h)
> linux-i386-low.o: linux-i386-low.c $(linux_low_h) $(server_h) \
> - $(gdb_proc_service_h)
> + $(gdb_proc_service_h) $(i386_low_h)
> linux-ia64-low.o: linux-ia64-low.c $(linux_low_h) $(server_h)
> linux-m32r-low.o: linux-m32r-low.c $(linux_low_h) $(server_h)
> linux-mips-low.o: linux-mips-low.c $(linux_low_h) $(server_h) \
> @@ -306,7 +310,7 @@ linux-ppc-low.o: linux-ppc-low.c $(linux
> linux-s390-low.o: linux-s390-low.c $(linux_low_h) $(server_h)
> linux-sh-low.o: linux-sh-low.c $(linux_low_h) $(server_h)
> linux-x86-64-low.o: linux-x86-64-low.c $(linux_low_h) $(server_h) \
> - $(gdb_proc_service_h)
> + $(gdb_proc_service_h) $(i386_low_h)
> linux-xtensa-low.o: linux-xtensa-low.c xtensa-xtregs.c $(linux_low_h) $(server_h)
>
> win32_low_h = $(srcdir)/win32-low.h
> @@ -314,7 +318,7 @@ win32_low_h = $(srcdir)/win32-low.h
> win32-low.o: win32-low.c $(win32_low_h) $(server_h) $(regdef_h) $(regcache_h)
>
> win32-arm-low.o: win32-arm-low.c $(win32_low_h) $(server_h)
> -win32-i386-low.o: win32-i386-low.c $(win32_low_h) $(server_h)
> +win32-i386-low.o: win32-i386-low.c $(win32_low_h) $(server_h) $(i386_low_h)
>
> spu-low.o: spu-low.c $(server_h)
>
> Index: configure.srv
> ===================================================================
> RCS file: /cvs/src/src/gdb/gdbserver/configure.srv,v
> retrieving revision 1.40
> diff -u -p -r1.40 configure.srv
> --- configure.srv 19 Apr 2009 17:54:52 -0000 1.40
> +++ configure.srv 30 Apr 2009 01:23:29 -0000
> @@ -53,10 +53,10 @@ case "${target}" in
> srv_linux_thread_db=yes
> ;;
> i[34567]86-*-cygwin*) srv_regobj=reg-i386.o
> - srv_tgtobj="win32-low.o win32-i386-low.o"
> + srv_tgtobj="i386-low.o win32-low.o win32-i386-low.o"
> ;;
> i[34567]86-*-linux*) srv_regobj=reg-i386-linux.o
> - srv_tgtobj="linux-low.o linux-i386-low.o i387-fp.o"
> + srv_tgtobj="linux-low.o linux-i386-low.o i386-low.o i387-fp.o"
> srv_linux_usrregs=yes
> srv_linux_regsets=yes
> srv_linux_thread_db=yes
> @@ -71,7 +71,7 @@ case "${target}" in
> srv_mingwce=yes
> ;;
> i[34567]86-*-mingw*) srv_regobj=reg-i386.o
> - srv_tgtobj="win32-low.o win32-i386-low.o"
> + srv_tgtobj="i386-low.o win32-low.o win32-i386-low.o"
> srv_mingw=yes
> ;;
> ia64-*-linux*) srv_regobj=reg-ia64.o
> @@ -170,7 +170,7 @@ case "${target}" in
> srv_tgtobj="spu-low.o"
> ;;
> x86_64-*-linux*) srv_regobj=reg-x86-64-linux.o
> - srv_tgtobj="linux-low.o linux-x86-64-low.o i387-fp.o"
> + srv_tgtobj="linux-low.o linux-x86-64-low.o i386-low.o i387-fp.o"
> srv_linux_regsets=yes
> srv_linux_thread_db=yes
> ;;
> Index: i386-low.c
> ===================================================================
> RCS file: i386-low.c
> diff -N i386-low.c
> --- /dev/null 1 Jan 1970 00:00:00 -0000
> +++ i386-low.c 30 Apr 2009 01:23:29 -0000
> @@ -0,0 +1,667 @@
> +/* Debug register code for the i386.
> +
> + Copyright (C) 2009
> + Free Software Foundation, Inc.
> +
> + This file is part of GDB.
> +
> + This program is free software; you can redistribute it and/or modify
> + it under the terms of the GNU General Public License as published by
> + the Free Software Foundation; either version 3 of the License, or
> + (at your option) any later version.
> +
> + This program is distributed in the hope that it will be useful,
> + but WITHOUT ANY WARRANTY; without even the implied warranty of
> + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
> + GNU General Public License for more details.
> +
> + You should have received a copy of the GNU General Public License
> + along with this program. If not, see <http://www.gnu.org/licenses/>. */
> +
> +#include "server.h"
> +#include "target.h"
> +#include "i386-low.h"
> +
> +/* Support for 8-byte wide hw watchpoints. */
> +#ifndef TARGET_HAS_DR_LEN_8
> +#define TARGET_HAS_DR_LEN_8 (sizeof (long) == 8)
> +#endif
> +
> +enum target_hw_bp_type
> + {
> + hw_write = 0, /* Common HW watchpoint */
> + hw_read = 1, /* Read HW watchpoint */
> + hw_access = 2, /* Access HW watchpoint */
> + hw_execute = 3 /* Execute HW breakpoint */
> + };
> +
> +/* DR7 Debug Control register fields. */
> +
> +/* How many bits to skip in DR7 to get to R/W and LEN fields. */
> +#define DR_CONTROL_SHIFT 16
> +/* How many bits in DR7 per R/W and LEN field for each watchpoint. */
> +#define DR_CONTROL_SIZE 4
> +
> +/* Watchpoint/breakpoint read/write fields in DR7. */
> +#define DR_RW_EXECUTE (0x0) /* Break on instruction execution. */
> +#define DR_RW_WRITE (0x1) /* Break on data writes. */
> +#define DR_RW_READ (0x3) /* Break on data reads or writes. */
> +
> +/* This is here for completeness. No platform supports this
> + functionality yet (as of March 2001). Note that the DE flag in the
> + CR4 register needs to be set to support this. */
> +#ifndef DR_RW_IORW
> +#define DR_RW_IORW (0x2) /* Break on I/O reads or writes. */
> +#endif
> +
> +/* Watchpoint/breakpoint length fields in DR7. The 2-bit left shift
> + is so we could OR this with the read/write field defined above. */
> +#define DR_LEN_1 (0x0 << 2) /* 1-byte region watch or breakpoint. */
> +#define DR_LEN_2 (0x1 << 2) /* 2-byte region watch. */
> +#define DR_LEN_4 (0x3 << 2) /* 4-byte region watch. */
> +#define DR_LEN_8 (0x2 << 2) /* 8-byte region watch (AMD64). */
> +
> +/* Local and Global Enable flags in DR7.
> +
> + When the Local Enable flag is set, the breakpoint/watchpoint is
> + enabled only for the current task; the processor automatically
> + clears this flag on every task switch. When the Global Enable flag
> + is set, the breakpoint/watchpoint is enabled for all tasks; the
> + processor never clears this flag.
> +
> + Currently, all watchpoint are locally enabled. If you need to
> + enable them globally, read the comment which pertains to this in
> + i386_insert_aligned_watchpoint below. */
> +#define DR_LOCAL_ENABLE_SHIFT 0 /* Extra shift to the local enable bit. */
> +#define DR_GLOBAL_ENABLE_SHIFT 1 /* Extra shift to the global enable bit. */
> +#define DR_ENABLE_SIZE 2 /* Two enable bits per debug register. */
> +
> +/* Local and global exact breakpoint enable flags (a.k.a. slowdown
> + flags). These are only required on i386, to allow detection of the
> + exact instruction which caused a watchpoint to break; i486 and
> + later processors do that automatically. We set these flags for
> + backwards compatibility. */
> +#define DR_LOCAL_SLOWDOWN (0x100)
> +#define DR_GLOBAL_SLOWDOWN (0x200)
> +
> +/* Fields reserved by Intel. This includes the GD (General Detect
> + Enable) flag, which causes a debug exception to be generated when a
> + MOV instruction accesses one of the debug registers.
> +
> + FIXME: My Intel manual says we should use 0xF800, not 0xFC00. */
> +#define DR_CONTROL_RESERVED (0xFC00)
> +
> +/* Auxiliary helper macros. */
> +
> +/* A value that masks all fields in DR7 that are reserved by Intel. */
> +#define I386_DR_CONTROL_MASK (~DR_CONTROL_RESERVED)
> +
> +/* The I'th debug register is vacant if its Local and Global Enable
> + bits are reset in the Debug Control register. */
> +#define I386_DR_VACANT(state, i) \
> + (((state)->dr_control_mirror & (3 << (DR_ENABLE_SIZE * (i)))) == 0)
> +
> +/* Locally enable the break/watchpoint in the I'th debug register. */
> +#define I386_DR_LOCAL_ENABLE(state, i) \
> + do { \
> + (state)->dr_control_mirror |= \
> + (1 << (DR_LOCAL_ENABLE_SHIFT + DR_ENABLE_SIZE * (i))); \
> + } while (0)
> +
> +/* Globally enable the break/watchpoint in the I'th debug register. */
> +#define I386_DR_GLOBAL_ENABLE(state, i) \
> + do { \
> + (state)->dr_control_mirror |= \
> + (1 << (DR_GLOBAL_ENABLE_SHIFT + DR_ENABLE_SIZE * (i))); \
> + } while (0)
> +
> +/* Disable the break/watchpoint in the I'th debug register. */
> +#define I386_DR_DISABLE(state, i) \
> + do { \
> + (state)->dr_control_mirror &= \
> + ~(3 << (DR_ENABLE_SIZE * (i))); \
> + } while (0)
> +
> +/* Set in DR7 the RW and LEN fields for the I'th debug register. */
> +#define I386_DR_SET_RW_LEN(state, i,rwlen) \
> + do { \
> + (state)->dr_control_mirror &= \
> + ~(0x0f << (DR_CONTROL_SHIFT+DR_CONTROL_SIZE*(i))); \
> + (state)->dr_control_mirror |= \
> + ((rwlen) << (DR_CONTROL_SHIFT+DR_CONTROL_SIZE*(i))); \
> + } while (0)
> +
> +/* Get from DR7 the RW and LEN fields for the I'th debug register. */
> +#define I386_DR_GET_RW_LEN(state, i) \
> + (((state)->dr_control_mirror >> (DR_CONTROL_SHIFT + DR_CONTROL_SIZE * (i))) & 0x0f)
> +
> +/* Did the watchpoint whose address is in the I'th register break? */
> +#define I386_DR_WATCH_HIT(state,i) ((state)->dr_status_mirror & (1 << (i)))
> +
> +/* A macro to loop over all debug registers. */
> +#define ALL_DEBUG_REGISTERS(i) for (i = 0; i < DR_NADDR; i++)
> +
> +/* Whether or not to print the mirrored debug registers. */
> +static int maint_show_dr = 0;
> +
> +/* Types of operations supported by i386_handle_nonaligned_watchpoint. */
> +typedef enum { WP_INSERT, WP_REMOVE, WP_COUNT } i386_wp_op_t;
> +
> +/* Internal functions. */
> +
> +/* Return the value of a 4-bit field for DR7 suitable for watching a
> + region of LEN bytes for accesses of type TYPE. LEN is assumed to
> + have the value of 1, 2, or 4. */
> +static unsigned i386_length_and_rw_bits (int len, enum target_hw_bp_type type);
> +
> +/* Insert a watchpoint at address ADDR, which is assumed to be aligned
> + according to the length of the region to watch. LEN_RW_BITS is the
> + value of the bit-field from DR7 which describes the length and
> + access type of the region to be watched by this watchpoint. Return
> + 0 on success, -1 on failure. */
> +static int i386_insert_aligned_watchpoint (struct i386_debug_reg_state *state,
> + CORE_ADDR addr,
> + unsigned len_rw_bits);
> +
> +/* Remove a watchpoint at address ADDR, which is assumed to be aligned
> + according to the length of the region to watch. LEN_RW_BITS is the
> + value of the bits from DR7 which describes the length and access
> + type of the region watched by this watchpoint. Return 0 on
> + success, -1 on failure. */
> +static int i386_remove_aligned_watchpoint (struct i386_debug_reg_state *state,
> + CORE_ADDR addr,
> + unsigned len_rw_bits);
> +
> +/* Insert or remove a (possibly non-aligned) watchpoint, or count the
> + number of debug registers required to watch a region at address
> + ADDR whose length is LEN for accesses of type TYPE. Return 0 on
> + successful insertion or removal, a positive number when queried
> + about the number of registers, or -1 on failure. If WHAT is not a
> + valid value, bombs through internal_error. */
> +static int i386_handle_nonaligned_watchpoint (struct i386_debug_reg_state *state,
> + i386_wp_op_t what,
> + CORE_ADDR addr, int len,
> + enum target_hw_bp_type type);
> +
> +/* Implementation. */
> +
> +/* Clear the reference counts and forget everything we knew about the
> + debug registers. */
> +
> +void
> +i386_low_cleanup_dregs (struct i386_debug_reg_state *state)
> +{
> + int i;
> +
> + ALL_DEBUG_REGISTERS(i)
> + {
> + state->dr_mirror[i] = 0;
> + state->dr_ref_count[i] = 0;
> + }
> + state->dr_control_mirror = 0;
> + state->dr_status_mirror = 0;
> +}
> +
> +/* Print the values of the mirrored debug registers. This is called
> + when maint_show_dr is non-zero. To set that up, type "maint
> + show-debug-regs" at GDB's prompt. */
> +
> +static void
> +i386_show_dr (struct i386_debug_reg_state *state,
> + const char *func, CORE_ADDR addr,
> + int len, enum target_hw_bp_type type)
> +{
> + int i;
> +
> + printf (func);
> + if (addr || len)
> + printf (" (addr=%lx, len=%d, type=%s)",
> + (unsigned long) addr, len,
> + type == hw_write ? "data-write"
> + : (type == hw_read ? "data-read"
> + : (type == hw_access ? "data-read/write"
> + : (type == hw_execute ? "instruction-execute"
> + /* FIXME: if/when I/O read/write
> + watchpoints are supported, add them
> + here. */
> + : "??unknown??"))));
> + printf (":\n");
> + printf ("\tCONTROL (DR7): %08x STATUS (DR6): %08x\n",
> + state->dr_control_mirror, state->dr_status_mirror);
> + ALL_DEBUG_REGISTERS (i)
> + {
> + printf ("\
> +\tDR%d: addr=0x%s, ref.count=%d DR%d: addr=0x%s, ref.count=%d\n",
> + i, paddr (state->dr_mirror[i]), state->dr_ref_count[i],
> + i+1, paddr (state->dr_mirror[i+1]), state->dr_ref_count[i+1]);
> + i++;
> + }
> +}
> +
> +/* Return the value of a 4-bit field for DR7 suitable for watching a
> + region of LEN bytes for accesses of type TYPE. LEN is assumed to
> + have the value of 1, 2, or 4. */
> +
> +static unsigned
> +i386_length_and_rw_bits (int len, enum target_hw_bp_type type)
> +{
> + unsigned rw;
> +
> + switch (type)
> + {
> + case hw_execute:
> + rw = DR_RW_EXECUTE;
> + break;
> + case hw_write:
> + rw = DR_RW_WRITE;
> + break;
> + case hw_read:
> + /* The i386 doesn't support data-read watchpoints. */
> + case hw_access:
> + rw = DR_RW_READ;
> + break;
> +#if 0
> + /* Not yet supported. */
> + case hw_io_access:
> + rw = DR_RW_IORW;
> + break;
> +#endif
> + default:
> + error ("\
> +Invalid hardware breakpoint type %d in i386_length_and_rw_bits.\n",
> + (int) type);
> + }
> +
> + switch (len)
> + {
> + case 1:
> + return (DR_LEN_1 | rw);
> + case 2:
> + return (DR_LEN_2 | rw);
> + case 4:
> + return (DR_LEN_4 | rw);
> + case 8:
> + if (TARGET_HAS_DR_LEN_8)
> + return (DR_LEN_8 | rw);
> + default:
> + error ("\
> +Invalid hardware breakpoint length %d in i386_length_and_rw_bits.\n", len);
> + }
> +}
> +
> +/* Insert a watchpoint at address ADDR, which is assumed to be aligned
> + according to the length of the region to watch. LEN_RW_BITS is the
> + value of the bits from DR7 which describes the length and access
> + type of the region to be watched by this watchpoint. Return 0 on
> + success, -1 on failure. */
> +
> +static int
> +i386_insert_aligned_watchpoint (struct i386_debug_reg_state *state,
> + CORE_ADDR addr, unsigned len_rw_bits)
> +{
> + int i;
> +
> + /* First, look for an occupied debug register with the same address
> + and the same RW and LEN definitions. If we find one, we can
> + reuse it for this watchpoint as well (and save a register). */
> + ALL_DEBUG_REGISTERS(i)
> + {
> + if (!I386_DR_VACANT (state, i)
> + && state->dr_mirror[i] == addr
> + && I386_DR_GET_RW_LEN (state, i) == len_rw_bits)
> + {
> + state->dr_ref_count[i]++;
> + return 0;
> + }
> + }
> +
> + /* Next, look for a vacant debug register. */
> + ALL_DEBUG_REGISTERS(i)
> + {
> + if (I386_DR_VACANT (state, i))
> + break;
> + }
> +
> + /* No more debug registers! */
> + if (i >= DR_NADDR)
> + return -1;
> +
> + /* Now set up the register I to watch our region. */
> +
> + /* Record the info in our local mirrored array. */
> + state->dr_mirror[i] = addr;
> + state->dr_ref_count[i] = 1;
> + I386_DR_SET_RW_LEN (state, i, len_rw_bits);
> + /* Note: we only enable the watchpoint locally, i.e. in the current
> + task. Currently, no i386 target allows or supports global
> + watchpoints; however, if any target would want that in the
> + future, GDB should probably provide a command to control whether
> + to enable watchpoints globally or locally, and the code below
> + should use global or local enable and slow-down flags as
> + appropriate. */
> + I386_DR_LOCAL_ENABLE (state, i);
> + state->dr_control_mirror |= DR_LOCAL_SLOWDOWN;
> + state->dr_control_mirror &= I386_DR_CONTROL_MASK;
> +
> + /* Finally, actually pass the info to the inferior. */
> + i386_dr_low_set_addr (i, addr);
> + i386_dr_low_set_control (state->dr_control_mirror);
> +
> + return 0;
> +}
> +
> +/* Reset a watched address for debug reg DR.
> + All implementations just do foo_set_addr (addr, 0), so this is a wrapper
> + around foo_set_addr to maintain the concept that this is a reset. */
> +
> +static void
> +i386_dr_low_reset_addr (int dr)
> +{
> + i386_dr_low_set_addr (dr, 0);
> +}
> +
> +/* Remove a watchpoint at address ADDR, which is assumed to be aligned
> + according to the length of the region to watch. LEN_RW_BITS is the
> + value of the bits from DR7 which describes the length and access
> + type of the region watched by this watchpoint. Return 0 on
> + success, -1 on failure. */
> +
> +static int
> +i386_remove_aligned_watchpoint (struct i386_debug_reg_state *state,
> + CORE_ADDR addr, unsigned len_rw_bits)
> +{
> + int i, retval = -1;
> +
> + ALL_DEBUG_REGISTERS(i)
> + {
> + if (!I386_DR_VACANT (state, i)
> + && state->dr_mirror[i] == addr
> + && I386_DR_GET_RW_LEN (state, i) == len_rw_bits)
> + {
> + if (--state->dr_ref_count[i] == 0) /* no longer in use? */
> + {
> + /* Reset our mirror. */
> + state->dr_mirror[i] = 0;
> + I386_DR_DISABLE (state, i);
> + /* Reset it in the inferior. */
> + i386_dr_low_set_control (state->dr_control_mirror);
> + i386_dr_low_reset_addr (i);
> + }
> + retval = 0;
> + }
> + }
> +
> + return retval;
> +}
> +
> +/* Insert or remove a (possibly non-aligned) watchpoint, or count the
> + number of debug registers required to watch a region at address
> + ADDR whose length is LEN for accesses of type TYPE. Return 0 on
> + successful insertion or removal, a positive number when queried
> + about the number of registers, or -1 on failure. If WHAT is not a
> + valid value, bombs through internal_error. */
> +
> +static int
> +i386_handle_nonaligned_watchpoint (struct i386_debug_reg_state *state,
> + i386_wp_op_t what, CORE_ADDR addr, int len,
> + enum target_hw_bp_type type)
> +{
> + int retval = 0, status = 0;
> + int max_wp_len = TARGET_HAS_DR_LEN_8 ? 8 : 4;
> +
> + static int size_try_array[8][8] =
> + {
> + {1, 1, 1, 1, 1, 1, 1, 1}, /* Trying size one. */
> + {2, 1, 2, 1, 2, 1, 2, 1}, /* Trying size two. */
> + {2, 1, 2, 1, 2, 1, 2, 1}, /* Trying size three. */
> + {4, 1, 2, 1, 4, 1, 2, 1}, /* Trying size four. */
> + {4, 1, 2, 1, 4, 1, 2, 1}, /* Trying size five. */
> + {4, 1, 2, 1, 4, 1, 2, 1}, /* Trying size six. */
> + {4, 1, 2, 1, 4, 1, 2, 1}, /* Trying size seven. */
> + {8, 1, 2, 1, 4, 1, 2, 1}, /* Trying size eight. */
> + };
> +
> + while (len > 0)
> + {
> + int align = addr % max_wp_len;
> + /* Four (eight on AMD64) is the maximum length a debug register
> + can watch. */
> + int try = (len > max_wp_len ? (max_wp_len - 1) : len - 1);
> + int size = size_try_array[try][align];
> +
> + if (what == WP_COUNT)
> + {
> + /* size_try_array[] is defined such that each iteration
> + through the loop is guaranteed to produce an address and a
> + size that can be watched with a single debug register.
> + Thus, for counting the registers required to watch a
> + region, we simply need to increment the count on each
> + iteration. */
> + retval++;
> + }
> + else
> + {
> + unsigned len_rw = i386_length_and_rw_bits (size, type);
> +
> + if (what == WP_INSERT)
> + status = i386_insert_aligned_watchpoint (state, addr, len_rw);
> + else if (what == WP_REMOVE)
> + status = i386_remove_aligned_watchpoint (state, addr, len_rw);
> +#if 0
> + else
> + internal_error (__FILE__, __LINE__, _("\
> +Invalid value %d of operation in i386_handle_nonaligned_watchpoint.\n"),
> + (int)what);
> +#endif
> + /* We keep the loop going even after a failure, because some
> + of the other aligned watchpoints might still succeed
> + (e.g. if they watch addresses that are already watched,
> + in which case we just increment the reference counts of
> + occupied debug registers). If we break out of the loop
> + too early, we could cause those addresses watched by
> + other watchpoints to be disabled when breakpoint.c reacts
> + to our failure to insert this watchpoint and tries to
> + remove it. */
> + if (status)
> + retval = status;
> + }
> +
> + addr += size;
> + len -= size;
> + }
> +
> + return retval;
> +}
> +
> +#define Z_PACKET_WRITE_WP '2'
> +#define Z_PACKET_READ_WP '3'
> +#define Z_PACKET_ACCESS_WP '4'
> +
> +static int
> +Z_packet_to_hw_type (char type)
> +{
> + switch (type)
> + {
> + case Z_PACKET_WRITE_WP: return hw_write;
> + case Z_PACKET_READ_WP: return hw_read;
> + case Z_PACKET_ACCESS_WP: return hw_access;
> + default:
> + error ("Z_packet_to_hw_type: bad watchpoint type %c", type);
> + }
> +}
> +
> +/* Insert a watchpoint to watch a memory region which starts at
> + address ADDR and whose length is LEN bytes. Watch memory accesses
> + of the type TYPE_FROM_PACKET. Return 0 on success, -1 on failure. */
> +
> +int
> +i386_low_insert_watchpoint (struct i386_debug_reg_state *state,
> + char type_from_packet, CORE_ADDR addr, int len)
> +{
> + int retval;
> + int type = Z_packet_to_hw_type (type_from_packet);
> +
> + if (((len != 1 && len !=2 && len !=4) && !(TARGET_HAS_DR_LEN_8 && len == 8))
> + || addr % len != 0)
> + {
> + retval = i386_handle_nonaligned_watchpoint (state, WP_INSERT,
> + addr, len, type);
> + }
> + else
> + {
> + unsigned len_rw = i386_length_and_rw_bits (len, type);
> +
> + retval = i386_insert_aligned_watchpoint (state, addr, len_rw);
> + }
> +
> + if (maint_show_dr)
> + i386_show_dr (state, "insert_watchpoint", addr, len, type);
> +
> + return retval;
> +}
> +
> +/* Remove a watchpoint that watched the memory region which starts at
> + address ADDR, whose length is LEN bytes, and for accesses of the
> + type TYPE_FROM_PACKET. Return 0 on success, -1 on failure. */
> +
> +int
> +i386_low_remove_watchpoint (struct i386_debug_reg_state *state,
> + char type_from_packet, CORE_ADDR addr, int len)
> +{
> + int retval;
> + int type = Z_packet_to_hw_type (type_from_packet);
> +
> + if (((len != 1 && len !=2 && len !=4) && !(TARGET_HAS_DR_LEN_8 && len == 8))
> + || addr % len != 0)
> + {
> + retval = i386_handle_nonaligned_watchpoint (state, WP_REMOVE,
> + addr, len, type);
> + }
> + else
> + {
> + unsigned len_rw = i386_length_and_rw_bits (len, type);
> +
> + retval = i386_remove_aligned_watchpoint (state, addr, len_rw);
> + }
> + if (maint_show_dr)
> + i386_show_dr (state, "remove_watchpoint", addr, len, type);
> + return retval;
> +}
> +
> +/* Return non-zero if we can watch a memory region that starts at
> + address ADDR and whose length is LEN bytes. */
> +
> +int
> +i386_low_region_ok_for_watchpoint (struct i386_debug_reg_state *state,
> + CORE_ADDR addr, int len)
> +{
> + int nregs;
> +
> + /* Compute how many aligned watchpoints we would need to cover this
> + region. */
> + nregs = i386_handle_nonaligned_watchpoint (state, WP_COUNT,
> + addr, len, hw_write);
> + return nregs <= DR_NADDR ? 1 : 0;
> +}
> +
> +/* If the inferior has some watchpoint that triggered, set the
> + address associated with that watchpoint and return non-zero.
> + Otherwise, return zero. */
> +
> +CORE_ADDR
> +i386_low_stopped_data_address (struct i386_debug_reg_state *state)
> +{
> + CORE_ADDR addr = 0;
> + int i;
> + int rc = 0;
> +
> + state->dr_status_mirror = i386_dr_low_get_status ();
> +
> + ALL_DEBUG_REGISTERS(i)
> + {
> + if (I386_DR_WATCH_HIT (state, i)
> + /* This second condition makes sure DRi is set up for a data
> + watchpoint, not a hardware breakpoint. The reason is
> + that GDB doesn't call the target_stopped_data_address
> + method except for data watchpoints. In other words, I'm
> + being paranoiac. */
> + && I386_DR_GET_RW_LEN (state, i) != 0)
> + {
> + addr = state->dr_mirror[i];
> + rc = 1;
> + if (maint_show_dr)
> + i386_show_dr (state, "watchpoint_hit", addr, -1, hw_write);
> + }
> + }
> + if (maint_show_dr && addr == 0)
> + i386_show_dr (state, "stopped_data_addr", 0, 0, hw_write);
> +
> + /* NOTE: gdb version checks rc != 0 here. */
> + return addr;
> +}
> +
> +int
> +i386_low_stopped_by_watchpoint (struct i386_debug_reg_state *state)
> +{
> + CORE_ADDR addr = 0;
> + /* NOTE: gdb version passes boolean found/not-found result from
> + i386_stopped_data_address. */
> + addr = i386_low_stopped_data_address (state);
> + return (addr != 0);
> +}
> +
> +/* Support for h/w breakpoints.
> + This support is not currently used, kept for reference. */
> +
> +/* Return non-zero if the inferior has some break/watchpoint that
> + triggered. */
> +
> +int
> +i386_low_stopped_by_hwbp (struct i386_debug_reg_state *state)
> +{
> + int i;
> +
> + state->dr_status_mirror = i386_dr_low_get_status ();
> + if (maint_show_dr)
> + i386_show_dr (state, "stopped_by_hwbp", 0, 0, hw_execute);
> +
> + ALL_DEBUG_REGISTERS(i)
> + {
> + if (I386_DR_WATCH_HIT (state, i))
> + return 1;
> + }
> +
> + return 0;
> +}
> +
> +/* Insert a hardware-assisted breakpoint at ADDR.
> + Return 0 on success, -1 on failure. */
> +
> +int
> +i386_low_insert_hw_breakpoint (struct i386_debug_reg_state *state,
> + CORE_ADDR addr)
> +{
> + unsigned len_rw = i386_length_and_rw_bits (1, hw_execute);
> + int retval = i386_insert_aligned_watchpoint (state, addr, len_rw);
> +
> + if (maint_show_dr)
> + i386_show_dr (state, "insert_hwbp", addr, 1, hw_execute);
> +
> + return retval;
> +}
> +
> +/* Remove a hardware-assisted breakpoint at ADDR.
> + Return 0 on success, -1 on failure. */
> +
> +int
> +i386_low_remove_hw_breakpoint (struct i386_debug_reg_state *state,
> + CORE_ADDR addr)
> +{
> + unsigned len_rw = i386_length_and_rw_bits (1, hw_execute);
> + int retval = i386_remove_aligned_watchpoint (state, addr, len_rw);
> +
> + if (maint_show_dr)
> + i386_show_dr (state, "remove_hwbp", addr, 1, hw_execute);
> +
> + return retval;
> +}
> Index: i386-low.h
> ===================================================================
> RCS file: i386-low.h
> diff -N i386-low.h
> --- /dev/null 1 Jan 1970 00:00:00 -0000
> +++ i386-low.h 30 Apr 2009 01:23:29 -0000
> @@ -0,0 +1,118 @@
> +/* Misc. low level support for i386.
> +
> + Copyright (C) 2009
> + Free Software Foundation, Inc.
> +
> + This file is part of GDB.
> +
> + This program is free software; you can redistribute it and/or modify
> + it under the terms of the GNU General Public License as published by
> + the Free Software Foundation; either version 3 of the License, or
> + (at your option) any later version.
> +
> + This program is distributed in the hope that it will be useful,
> + but WITHOUT ANY WARRANTY; without even the implied warranty of
> + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
> + GNU General Public License for more details.
> +
> + You should have received a copy of the GNU General Public License
> + along with this program. If not, see <http://www.gnu.org/licenses/>. */
> +
> +/* Support for hardware watchpoints and breakpoints using the i386
> + debug registers.
> +
> + This provides several functions for inserting and removing
> + hardware-assisted breakpoints and watchpoints, testing if one or
> + more of the watchpoints triggered and at what address, checking
> + whether a given region can be watched, etc.
> +
> + The functions below implement debug registers sharing by reference
> + counts, and allow to watch regions up to 16 bytes long
> + (32 bytes on 64 bit hosts). */
> +
> +
> +/* Debug registers' indices. */
> +#define DR_FIRSTADDR 0
> +#define DR_LASTADDR 3
> +#define DR_NADDR 4 /* The number of debug address registers. */
> +#define DR_STATUS 6
> +#define DR_CONTROL 7
> +
> +/* Global state needed to track h/w watchpoints. */
> +
> +struct i386_debug_reg_state
> +{
> + /* Mirror the inferior's DRi registers. We keep the status and
> + control registers separated because they don't hold addresses. */
> + CORE_ADDR dr_mirror[DR_NADDR];
> + unsigned dr_status_mirror, dr_control_mirror;
> +
> + /* Reference counts for each debug register. */
> + int dr_ref_count[DR_NADDR];
> +};
> +
> +/* Clear the reference counts and forget everything we knew about DRi. */
> +extern void i386_low_cleanup_dregs (struct i386_debug_reg_state *state);
> +
> +/* Insert a watchpoint to watch a memory region which starts at
> + address ADDR and whose length is LEN bytes. Watch memory accesses
> + of the type TYPE_FROM_PACKET. Return 0 on success, -1 on failure. */
> +extern int i386_low_insert_watchpoint (struct i386_debug_reg_state *state,
> + char type_from_packet, CORE_ADDR addr,
> + int len);
> +
> +/* Remove a watchpoint that watched the memory region which starts at
> + address ADDR, whose length is LEN bytes, and for accesses of the
> + type TYPE_FROM_PACKET. Return 0 on success, -1 on failure. */
> +extern int i386_low_remove_watchpoint (struct i386_debug_reg_state *state,
> + char type_from_packet, CORE_ADDR addr,
> + int len);
> +
> +/* Return non-zero if we can watch a memory region that starts at
> + address ADDR and whose length is LEN bytes. */
> +extern int i386_low_region_ok_for_watchpoint (struct i386_debug_reg_state *state,
> + CORE_ADDR addr, int len);
> +
> +/* If the inferior has some break/watchpoint that triggered, set
> + the address associated with that break/watchpoint and return
> + true. Otherwise, return false. */
> +extern CORE_ADDR i386_low_stopped_data_address (struct i386_debug_reg_state *state);
> +
> +extern int i386_low_stopped_by_watchpoint (struct i386_debug_reg_state *state);
> +
> +/* Return non-zero if the inferior has some break/watchpoint that
> + triggered. */
> +extern int i386_low_stopped_by_hwbp (struct i386_debug_reg_state *state);
> +
> +/* Insert a hardware-assisted breakpoint at ADDR.
> + Return 0 on success, -1 on failure. */
> +extern int i386_low_insert_hw_breakpoint (struct i386_debug_reg_state *state,
> + CORE_ADDR addr);
> +
> +/* Remove a hardware-assisted breakpoint at ADDR.
> + Return 0 on success, -1 on failure. */
> +extern int i386_low_remove_hw_breakpoint (struct i386_debug_reg_state *state,
> + CORE_ADDR addr);
> +
> +/* Each target needs to provide several low-level functions
> + that will be called to insert watchpoints and hardware breakpoints
> + into the inferior, remove them, and check their status. These
> + functions are:
> +
> + i386_dr_low_set_control -- set the debug control (DR7)
> + register to a given value
> +
> + i386_dr_low_set_addr -- put an address into one debug register
> +
> + i386_dr_low_get_status -- return the value of the debug
> + status (DR6) register.
> +*/
> +
> +/* Pass the address ADDR to the inferior in the I'th debug register. */
> +extern void i386_dr_low_set_addr (int i, CORE_ADDR addr);
> +
> +/* Pass the value VAL to the inferior in the DR7 debug control register. */
> +extern void i386_dr_low_set_control (unsigned val);
> +
> +/* Get the value of the DR6 debug status register from the inferior. */
> +extern unsigned i386_dr_low_get_status (void);
> Index: linux-i386-low.c
> ===================================================================
> RCS file: /cvs/src/src/gdb/gdbserver/linux-i386-low.c,v
> retrieving revision 1.19
> diff -u -p -r1.19 linux-i386-low.c
> --- linux-i386-low.c 22 Mar 2009 23:57:10 -0000 1.19
> +++ linux-i386-low.c 30 Apr 2009 01:23:29 -0000
> @@ -17,9 +17,11 @@
> You should have received a copy of the GNU General Public License
> along with this program. If not, see <http://www.gnu.org/licenses/>. */
>
> +#include <stddef.h>
> #include "server.h"
> #include "linux-low.h"
> #include "i387-fp.h"
> +#include "i386-low.h"
>
> #include "gdb_proc_service.h"
>
> @@ -33,10 +35,14 @@
> #define PTRACE_GET_THREAD_AREA 25
> #endif
>
> +struct arch_process_info
> +{
> + struct i386_debug_reg_state debug_reg_state;
> +};
> +
> /* Defined in auto-generated file reg-i386-linux.c. */
> void init_registers_i386_linux (void);
>
> -
> /* This module only supports access to the general purpose registers. */
>
> #define i386_num_regs 16
> @@ -187,6 +193,148 @@ i386_breakpoint_at (CORE_ADDR pc)
>
> return 0;
> }
> +
> +/* Support for debug registers. */
> +
> +static unsigned long
> +i386_linux_dr_get (ptid_t ptid, int regnum)
> +{
> + int tid;
> + unsigned long value;
> +
> + tid = TIDGET (ptid);
> + if (tid == 0)
> + tid = PIDGET (ptid);
> +
> + errno = 0;
> + value = ptrace (PTRACE_PEEKUSER, tid,
> + offsetof (struct user, u_debugreg[regnum]), 0);
> + if (errno != 0)
> + error ("Couldn't read debug register");
> +
> + return value;
> +}
> +
> +static void
> +i386_linux_dr_set (ptid_t ptid, int regnum, unsigned long value)
> +{
> + int tid;
> +
> + tid = TIDGET (ptid);
> + if (tid == 0)
> + tid = PIDGET (ptid);
> +
> + errno = 0;
> + ptrace (PTRACE_POKEUSER, tid,
> + offsetof (struct user, u_debugreg[regnum]), value);
> + if (errno != 0)
> + error ("Couldn't write debug register");
> +}
> +
> +/* Pass the address ADDR to the inferior in debug register REGNUM. */
> +
> +void
> +i386_dr_low_set_addr (int regnum, CORE_ADDR addr)
> +{
> + struct inferior_list_entry *lp;
> +
> + if (! (regnum >= 0 && regnum <= DR_LASTADDR - DR_FIRSTADDR))
> + error ("Invalid debug register");
> +
> + for (lp = all_lwps.head; lp; lp = lp->next)
> + {
> + struct lwp_info *lwp = (struct lwp_info *) lp;
> + i386_linux_dr_set (ptid_of (lwp), DR_FIRSTADDR + regnum, addr);
> + }
> +}
> +
> +/* Pass the value VAL to the inferior in the DR7 debug control register. */
> +
> +void
> +i386_dr_low_set_control (unsigned control)
> +{
> + struct inferior_list_entry *lp;
> +
> + for (lp = all_lwps.head; lp; lp = lp->next)
> + {
> + struct lwp_info *lwp = (struct lwp_info *) lp;
> + i386_linux_dr_set (ptid_of (lwp), DR_CONTROL, control);
> + }
> +}
> +
> +/* Get the value of the DR6 debug status register from the inferior. */
> +
> +unsigned
> +i386_dr_low_get_status (void)
> +{
> + ptid_t inferior_ptid = ptid_of (get_thread_lwp (current_inferior));
> + return i386_linux_dr_get (inferior_ptid, DR_STATUS);
> +}
> +
> +/* Watchpoint support. */
> +
> +static int
> +i386_insert_watchpoint (struct arch_process_info *arch_private,
> + char type, CORE_ADDR addr, int len)
> +{
> + return i386_low_insert_watchpoint (&arch_private->debug_reg_state,
> + type, addr, len);
> +}
> +
> +static int
> +i386_remove_watchpoint (struct arch_process_info *arch_private,
> + char type, CORE_ADDR addr, int len)
> +{
> + return i386_low_remove_watchpoint (&arch_private->debug_reg_state,
> + type, addr, len);
> +}
> +
> +static int
> +i386_stopped_by_watchpoint (struct arch_process_info *arch_private)
> +{
> + return i386_low_stopped_by_watchpoint (&arch_private->debug_reg_state);
> +}
> +
> +static CORE_ADDR
> +i386_stopped_data_address (struct arch_process_info *arch_private)
> +{
> + return i386_low_stopped_data_address (&arch_private->debug_reg_state);
> +}
> +
> +/* Called when a new process is created. */
> +
> +struct arch_process_info *
> +i386_linux_new_process (int pid, int attached)
> +{
> + struct arch_process_info *info = xcalloc (1, sizeof (*info));
> +
> + return info;
> +}
> +
> +/* Called when a new thread is detected.
> + INITIAL is non-zero for the main thread, zero otherwise. */
> +
> +static void
> +i386_linux_new_thread (struct lwp_info *lwp, int initial)
> +{
> + /* The initial thread has debug regs set later during process
> + creation/attaching handling. */
> +
> + if (! initial)
> + {
> + int i;
> + ptid_t ptid = ptid_of (lwp);
> + int pid = PIDGET (ptid);
> + struct process_info *proc = find_process_pid (pid);
> + struct arch_process_info *arch_private = proc->private->arch_private;
> + struct i386_debug_reg_state *state = &arch_private->debug_reg_state;
> +
> + for (i = DR_FIRSTADDR; i <= DR_LASTADDR; i++)
> + i386_linux_dr_set (ptid, i, state->dr_mirror[i]);
> +
> + i386_linux_dr_set (ptid, DR_CONTROL, state->dr_control_mirror);
> + }
> +}
>
> struct linux_target_ops the_low_target = {
> init_registers_i386_linux,
> @@ -201,10 +349,12 @@ struct linux_target_ops the_low_target =
> NULL,
> 1,
> i386_breakpoint_at,
> + i386_insert_watchpoint,
> + i386_remove_watchpoint,
> + i386_stopped_by_watchpoint,
> + i386_stopped_data_address,
> NULL,
> NULL,
> - NULL,
> - NULL,
> - NULL,
> - NULL,
> + i386_linux_new_process,
> + i386_linux_new_thread
> };
> Index: linux-low.c
> ===================================================================
> RCS file: /cvs/src/src/gdb/gdbserver/linux-low.c,v
> retrieving revision 1.97
> diff -u -p -r1.97 linux-low.c
> --- linux-low.c 3 Apr 2009 11:40:02 -0000 1.97
> +++ linux-low.c 30 Apr 2009 06:26:54 -0000
> @@ -120,6 +120,7 @@ static int must_set_ptrace_flags;
> control of gdbserver have the same architecture. */
> static int new_inferior;
>
> +static void notify_low_target_new_thread (struct lwp_info *lwp, int initial);
> static void linux_resume_one_lwp (struct inferior_list_entry *entry,
> int step, int signal, siginfo_t *info);
> static void linux_resume (struct thread_resume *resume_info, size_t n);
> @@ -179,6 +180,9 @@ linux_add_process (int pid, int attached
> proc = add_process (pid, attached);
> proc->private = xcalloc (1, sizeof (*proc->private));
>
> + if (the_low_target.new_process != NULL)
> + proc->private->arch_private = the_low_target.new_process (pid, attached);
> +
> return proc;
> }
>
> @@ -188,6 +192,7 @@ linux_add_process (int pid, int attached
> static void
> linux_remove_process (struct process_info *process)
> {
> + free (process->private->arch_private);
> free (process->private);
> remove_process (process);
> }
> @@ -231,6 +236,7 @@ handle_extended_wait (struct lwp_info *e
> ptid = ptid_build (pid_of (event_child), new_pid, 0);
> new_lwp = (struct lwp_info *) add_lwp (ptid);
> add_thread (ptid, new_lwp);
> + notify_low_target_new_thread (new_lwp, 0);
>
> /* Normally we will get the pending SIGSTOP. But in some cases
> we might get another signal delivered to the group first.
> @@ -313,6 +319,18 @@ add_lwp (ptid_t ptid)
> return lwp;
> }
>
> +/* Notify the backend that we have a new thread, be it the main thread
> + or a later one.
> + INITIAL is non-zero for the main thread, zero otherwise.
> + NOTE: This must be called when the thread is stopped. */
> +
> +static void
> +notify_low_target_new_thread (struct lwp_info *lwp, int initial)
> +{
> + if (the_low_target.new_thread != NULL)
> + the_low_target.new_thread (lwp, initial);
> +}
> +
> /* Start an inferior process and returns its pid.
> ALLARGS is a vector of program-name and args. */
>
> @@ -354,6 +372,8 @@ linux_create_inferior (char *program, ch
> ptid = ptid_build (pid, pid, 0);
> new_lwp = add_lwp (ptid);
> add_thread (ptid, new_lwp);
> + /* We can't call notify_low_target_new_thread there, the thread isn't
> + stopped. Piggyback on must_set_ptrace_flags and call it then. */
> must_set_ptrace_flags = 1;
>
> return pid;
> @@ -401,6 +421,7 @@ linux_attach_lwp_1 (unsigned long lwpid,
>
> new_lwp = (struct lwp_info *) add_lwp (ptid);
> add_thread (ptid, new_lwp);
> + notify_low_target_new_thread (new_lwp, initial);
>
> /* The next time we wait for this LWP we'll see a SIGSTOP as PTRACE_ATTACH
> brings it to a halt.
> @@ -1261,6 +1282,7 @@ retry:
> if (must_set_ptrace_flags)
> {
> ptrace (PTRACE_SETOPTIONS, lwpid_of (lwp), 0, PTRACE_O_TRACECLONE);
> + notify_low_target_new_thread (lwp, 1);
> must_set_ptrace_flags = 0;
> }
> /* If we are waiting for a particular child, and it exited,
> @@ -2599,7 +2623,11 @@ static int
> linux_insert_watchpoint (char type, CORE_ADDR addr, int len)
> {
> if (the_low_target.insert_watchpoint != NULL)
> - return the_low_target.insert_watchpoint (type, addr, len);
> + {
> + struct process_info *proc = current_process ();
> + return the_low_target.insert_watchpoint (proc->private->arch_private,
> + type, addr, len);
> + }
> else
> /* Unsupported (see target.h). */
> return 1;
> @@ -2609,7 +2637,11 @@ static int
> linux_remove_watchpoint (char type, CORE_ADDR addr, int len)
> {
> if (the_low_target.remove_watchpoint != NULL)
> - return the_low_target.remove_watchpoint (type, addr, len);
> + {
> + struct process_info *proc = current_process ();
> + return the_low_target.remove_watchpoint (proc->private->arch_private,
> + type, addr, len);
> + }
> else
> /* Unsupported (see target.h). */
> return 1;
> @@ -2619,7 +2651,10 @@ static int
> linux_stopped_by_watchpoint (void)
> {
> if (the_low_target.stopped_by_watchpoint != NULL)
> - return the_low_target.stopped_by_watchpoint ();
> + {
> + struct process_info *proc = current_process ();
> + return the_low_target.stopped_by_watchpoint (proc->private->arch_private);
> + }
> else
> return 0;
> }
> @@ -2628,7 +2663,10 @@ static CORE_ADDR
> linux_stopped_data_address (void)
> {
> if (the_low_target.stopped_data_address != NULL)
> - return the_low_target.stopped_data_address ();
> + {
> + struct process_info *proc = current_process ();
> + return the_low_target.stopped_data_address (proc->private->arch_private);
> + }
> else
> return 0;
> }
> Index: linux-low.h
> ===================================================================
> RCS file: /cvs/src/src/gdb/gdbserver/linux-low.h,v
> retrieving revision 1.28
> diff -u -p -r1.28 linux-low.h
> --- linux-low.h 1 Apr 2009 22:50:24 -0000 1.28
> +++ linux-low.h 30 Apr 2009 01:23:29 -0000
> @@ -54,8 +54,13 @@ struct process_info_private
>
> /* Connection to the libthread_db library. */
> td_thragent_t *thread_agent;
> +
> + /* Target-specific additions. */
> + struct arch_process_info *arch_private;
> };
>
> +struct lwp_info;
> +
> struct linux_target_ops
> {
> /* Architecture-specific setup. */
> @@ -75,26 +80,37 @@ struct linux_target_ops
> int breakpoint_len;
> CORE_ADDR (*breakpoint_reinsert_addr) (void);
>
> -
> int decr_pc_after_break;
> int (*breakpoint_at) (CORE_ADDR pc);
>
> /* Watchpoint related functions. See target.h for comments. */
> - int (*insert_watchpoint) (char type, CORE_ADDR addr, int len);
> - int (*remove_watchpoint) (char type, CORE_ADDR addr, int len);
> - int (*stopped_by_watchpoint) (void);
> - CORE_ADDR (*stopped_data_address) (void);
> + int (*insert_watchpoint) (struct arch_process_info *arch_private,
> + char type, CORE_ADDR addr, int len);
> + int (*remove_watchpoint) (struct arch_process_info *arch_private,
> + char type, CORE_ADDR addr, int len);
> + int (*stopped_by_watchpoint) (struct arch_process_info *arch_private);
> + CORE_ADDR (*stopped_data_address) (struct arch_process_info *arch_private);
>
> /* Hooks to reformat register data for PEEKUSR/POKEUSR (in particular
> for registers smaller than an xfer unit). */
> void (*collect_ptrace_register) (int regno, char *buf);
> void (*supply_ptrace_register) (int regno, const char *buf);
> +
> + /* Hook to call when a new process is created or attached to. */
> + struct arch_process_info * (*new_process) (int pid, int attached);
> +
> + /* Hook to call when a new thread is detected.
> + INITIAL is non-zero for the main thread, zero otherwise. */
> + void (*new_thread) (struct lwp_info *, int initial);
> };
>
> extern struct linux_target_ops the_low_target;
>
> +#define ptid_of(proc) ((proc)->head.id)
> #define pid_of(proc) ptid_get_pid ((proc)->head.id)
> #define lwpid_of(proc) ptid_get_lwp ((proc)->head.id)
> +#define PIDGET(ptid) ptid_get_pid (ptid)
> +#define TIDGET(ptid) ptid_get_lwp (ptid)
>
> #define get_lwp(inf) ((struct lwp_info *)(inf))
> #define get_thread_lwp(thr) (get_lwp (inferior_target_data (thr)))
> Index: linux-x86-64-low.c
> ===================================================================
> RCS file: /cvs/src/src/gdb/gdbserver/linux-x86-64-low.c,v
> retrieving revision 1.22
> diff -u -p -r1.22 linux-x86-64-low.c
> --- linux-x86-64-low.c 22 Mar 2009 23:57:10 -0000 1.22
> +++ linux-x86-64-low.c 30 Apr 2009 01:23:29 -0000
> @@ -18,9 +18,11 @@
> You should have received a copy of the GNU General Public License
> along with this program. If not, see <http://www.gnu.org/licenses/>. */
>
> +#include <stddef.h>
> #include "server.h"
> #include "linux-low.h"
> #include "i387-fp.h"
> +#include "i386-low.h"
>
> #include "gdb_proc_service.h"
>
> @@ -45,6 +47,11 @@ void init_registers_x86_64_linux (void);
> #define ARCH_GET_GS 0x1004
> #endif
>
> +struct arch_process_info
> +{
> + struct i386_debug_reg_state debug_reg_state;
> +};
> +
> static int x86_64_regmap[] = {
> RAX * 8, RBX * 8, RCX * 8, RDX * 8,
> RSI * 8, RDI * 8, RBP * 8, RSP * 8,
> @@ -161,6 +168,148 @@ x86_64_breakpoint_at (CORE_ADDR pc)
>
> return 0;
> }
> +
> +/* Support for debug registers. */
> +
> +static unsigned long
> +x86_64_linux_dr_get (ptid_t ptid, int regnum)
> +{
> + int tid;
> + unsigned long value;
> +
> + tid = TIDGET (ptid);
> + if (tid == 0)
> + tid = PIDGET (ptid);
> +
> + errno = 0;
> + value = ptrace (PTRACE_PEEKUSER, tid,
> + offsetof (struct user, u_debugreg[regnum]), 0);
> + if (errno != 0)
> + error ("Couldn't read debug register");
> +
> + return value;
> +}
> +
> +static void
> +x86_64_linux_dr_set (ptid_t ptid, int regnum, unsigned long value)
> +{
> + int tid;
> +
> + tid = TIDGET (ptid);
> + if (tid == 0)
> + tid = PIDGET (ptid);
> +
> + errno = 0;
> + ptrace (PTRACE_POKEUSER, tid,
> + offsetof (struct user, u_debugreg[regnum]), value);
> + if (errno != 0)
> + error ("Couldn't write debug register");
> +}
> +
> +/* Pass the address ADDR to the inferior in debug register REGNUM. */
> +
> +void
> +i386_dr_low_set_addr (int regnum, CORE_ADDR addr)
> +{
> + struct inferior_list_entry *lp;
> +
> + if (! (regnum >= 0 && regnum <= DR_LASTADDR - DR_FIRSTADDR))
> + error ("Invalid debug register");
> +
> + for (lp = all_lwps.head; lp; lp = lp->next)
> + {
> + struct lwp_info *lwp = (struct lwp_info *) lp;
> + x86_64_linux_dr_set (ptid_of (lwp), DR_FIRSTADDR + regnum, addr);
> + }
> +}
> +
> +/* Pass the value VAL to the inferior in the DR7 debug control register. */
> +
> +void
> +i386_dr_low_set_control (unsigned control)
> +{
> + struct inferior_list_entry *lp;
> +
> + for (lp = all_lwps.head; lp; lp = lp->next)
> + {
> + struct lwp_info *lwp = (struct lwp_info *) lp;
> + x86_64_linux_dr_set (ptid_of (lwp), DR_CONTROL, control);
> + }
> +}
> +
> +/* Get the value of the DR6 debug status register from the inferior. */
> +
> +unsigned
> +i386_dr_low_get_status (void)
> +{
> + ptid_t inferior_ptid = ptid_of (get_thread_lwp (current_inferior));
> + return x86_64_linux_dr_get (inferior_ptid, DR_STATUS);
> +}
> +
> +/* Watchpoint support. */
> +
> +static int
> +x86_64_insert_watchpoint (struct arch_process_info *arch_private,
> + char type, CORE_ADDR addr, int len)
> +{
> + return i386_low_insert_watchpoint (&arch_private->debug_reg_state,
> + type, addr, len);
> +}
> +
> +static int
> +x86_64_remove_watchpoint (struct arch_process_info *arch_private,
> + char type, CORE_ADDR addr, int len)
> +{
> + return i386_low_remove_watchpoint (&arch_private->debug_reg_state,
> + type, addr, len);
> +}
> +
> +static int
> +x86_64_stopped_by_watchpoint (struct arch_process_info *arch_private)
> +{
> + return i386_low_stopped_by_watchpoint (&arch_private->debug_reg_state);
> +}
> +
> +static CORE_ADDR
> +x86_64_stopped_data_address (struct arch_process_info *arch_private)
> +{
> + return i386_low_stopped_data_address (&arch_private->debug_reg_state);
> +}
> +
> +/* Called when a new process is created. */
> +
> +struct arch_process_info *
> +x86_64_linux_new_process (int pid, int attached)
> +{
> + struct arch_process_info *info = xcalloc (1, sizeof (*info));
> +
> + return info;
> +}
> +
> +/* Called when a new thread is detected.
> + INITIAL is non-zero for the main thread, zero otherwise. */
> +
> +static void
> +x86_64_linux_new_thread (struct lwp_info *lwp, int initial)
> +{
> + /* The initial thread has debug regs set later during process
> + creation/attaching handling. */
> +
> + if (! initial)
> + {
> + int i;
> + ptid_t ptid = ptid_of (lwp);
> + int pid = PIDGET (ptid);
> + struct process_info *proc = find_process_pid (pid);
> + struct arch_process_info *arch_private = proc->private->arch_private;
> + struct i386_debug_reg_state *state = &arch_private->debug_reg_state;
> +
> + for (i = DR_FIRSTADDR; i <= DR_LASTADDR; i++)
> + x86_64_linux_dr_set (ptid, i, state->dr_mirror[i]);
> +
> + x86_64_linux_dr_set (ptid, DR_CONTROL, state->dr_control_mirror);
> + }
> +}
>
> struct linux_target_ops the_low_target = {
> init_registers_x86_64_linux,
> @@ -175,10 +324,12 @@ struct linux_target_ops the_low_target =
> NULL,
> 1,
> x86_64_breakpoint_at,
> + x86_64_insert_watchpoint,
> + x86_64_remove_watchpoint,
> + x86_64_stopped_by_watchpoint,
> + x86_64_stopped_data_address,
> NULL,
> NULL,
> - NULL,
> - NULL,
> - NULL,
> - NULL,
> + x86_64_linux_new_process,
> + x86_64_linux_new_thread
> };
> Index: server.h
> ===================================================================
> RCS file: /cvs/src/src/gdb/gdbserver/server.h,v
> retrieving revision 1.56
> diff -u -p -r1.56 server.h
> --- server.h 3 Apr 2009 20:15:51 -0000 1.56
> +++ server.h 30 Apr 2009 01:23:29 -0000
> @@ -405,6 +405,7 @@ void perror_with_name (const char *strin
> void error (const char *string,...) ATTR_NORETURN ATTR_FORMAT (printf, 1, 2);
> void fatal (const char *string,...) ATTR_NORETURN ATTR_FORMAT (printf, 1, 2);
> void warning (const char *string,...) ATTR_FORMAT (printf, 1, 2);
> +char *paddr (CORE_ADDR addr);
>
> /* Maximum number of bytes to read/write at once. The value here
> is chosen to fill up a packet (the headers account for the 32). */
> Index: utils.c
> ===================================================================
> RCS file: /cvs/src/src/gdb/gdbserver/utils.c,v
> retrieving revision 1.18
> diff -u -p -r1.18 utils.c
> --- utils.c 19 Jan 2009 00:16:46 -0000 1.18
> +++ utils.c 30 Apr 2009 01:23:29 -0000
> @@ -170,3 +170,37 @@ warning (const char *string,...)
> fprintf (stderr, "\n");
> va_end (args);
> }
> +
> +/* temporary storage using circular buffer */
> +#define NUMCELLS 4
> +#define CELLSIZE 50
> +static char *
> +get_cell (void)
> +{
> + static char buf[NUMCELLS][CELLSIZE];
> + static int cell = 0;
> + if (++cell >= NUMCELLS)
> + cell = 0;
> + return buf[cell];
> +}
> +
> +static int
> +xsnprintf (char *str, size_t size, const char *format, ...)
> +{
> + va_list args;
> + int ret;
> +
> + va_start (args, format);
> + ret = vsnprintf (str, size, format, args);
> + va_end (args);
> +
> + return ret;
> +}
> +
> +char *
> +paddr (CORE_ADDR addr)
> +{
> + char *str = get_cell ();
> + xsnprintf (str, CELLSIZE, "%lx", (long) addr);
> + return str;
> +}
> Index: win32-arm-low.c
> ===================================================================
> RCS file: /cvs/src/src/gdb/gdbserver/win32-arm-low.c,v
> retrieving revision 1.8
> diff -u -p -r1.8 win32-arm-low.c
> --- win32-arm-low.c 3 Jan 2009 05:57:57 -0000 1.8
> +++ win32-arm-low.c 30 Apr 2009 01:23:29 -0000
> @@ -122,4 +122,9 @@ struct win32_target_ops the_low_target =
> NULL, /* single_step */
> (const unsigned char *) &arm_wince_breakpoint,
> arm_wince_breakpoint_len,
> + /* Watchpoint related functions. See target.h for comments. */
> + NULL, /* insert_watchpoint */
> + NULL, /* remove_watchpoint */
> + NULL, /* stopped_by_watchpoint */
> + NULL /* stopped_data_address */
> };
> Index: win32-i386-low.c
> ===================================================================
> RCS file: /cvs/src/src/gdb/gdbserver/win32-i386-low.c,v
> retrieving revision 1.14
> diff -u -p -r1.14 win32-i386-low.c
> --- win32-i386-low.c 3 Jan 2009 05:57:57 -0000 1.14
> +++ win32-i386-low.c 30 Apr 2009 01:23:29 -0000
> @@ -17,6 +17,7 @@
>
> #include "server.h"
> #include "win32-low.h"
> +#include "i386-low.h"
>
> #define FCS_REGNUM 27
> #define FOP_REGNUM 31
> @@ -31,6 +32,42 @@ static unsigned dr[8];
> static int debug_registers_changed = 0;
> static int debug_registers_used = 0;
>
> +/* Pass the address ADDR to the inferior in the I'th debug register.
> + Here we just store the address in dr array, the registers will be
> + actually set up when windows_continue is called. */
> +
> +void
> +i386_dr_low_set_addr (int i, CORE_ADDR addr)
> +{
> + if (i < 0 || i > 3)
> + return;
> + dr[i] = (unsigned) addr;
> + debug_registers_changed = 1;
> + debug_registers_used = 1;
> +}
> +
> +/* Pass the value VAL to the inferior in the DR7 debug control register.
> + Here we just store the address in D_REGS, the watchpoint
> + will be actually set up in windows_wait. */
> +
> +void
> +i386_dr_low_set_control (unsigned val)
> +{
> + dr[7] = val;
> + debug_registers_changed = 1;
> + debug_registers_used = 1;
> +}
> +
> +/* Get the value of the DR6 debug status register from the inferior.
> + Here we just return the value stored in dr[6]
> + by the last call to thread_rec for current_event.dwThreadId id. */
> +
> +unsigned
> +i386_dr_low_get_status (void)
> +{
> + return dr[6];
> +}
> +
> static void
> i386_initial_stuff (void)
> {
> @@ -205,4 +242,8 @@ struct win32_target_ops the_low_target =
> i386_single_step,
> NULL, /* breakpoint */
> 0, /* breakpoint_len */
> + i386_insert_watchpoint,
> + i386_remove_watchpoint,
> + i386_stopped_by_watchpoint,
> + i386_stopped_data_address
> };
> Index: win32-low.c
> ===================================================================
> RCS file: /cvs/src/src/gdb/gdbserver/win32-low.c,v
> retrieving revision 1.35
> diff -u -p -r1.35 win32-low.c
> --- win32-low.c 1 Apr 2009 22:50:24 -0000 1.35
> +++ win32-low.c 30 Apr 2009 01:23:29 -0000
> @@ -228,6 +228,48 @@ child_delete_thread (DWORD pid, DWORD ti
> delete_thread_info (thread);
> }
>
> +/* These watchpoint related wrapper functions simply pass on the function call
> + if the target has registered a corresponding function. */
> +
> +static int
> +win32_insert_watchpoint (char type, CORE_ADDR addr, int len)
> +{
> + if (the_low_target.insert_watchpoint != NULL)
> + return the_low_target.insert_watchpoint (type, addr, len);
> + else
> + /* Unsupported (see target.h). */
> + return 1;
> +}
> +
> +static int
> +win32_remove_watchpoint (char type, CORE_ADDR addr, int len)
> +{
> + if (the_low_target.remove_watchpoint != NULL)
> + return the_low_target.remove_watchpoint (type, addr, len);
> + else
> + /* Unsupported (see target.h). */
> + return 1;
> +}
> +
> +static int
> +win32_stopped_by_watchpoint (void)
> +{
> + if (the_low_target.stopped_by_watchpoint != NULL)
> + return the_low_target.stopped_by_watchpoint ();
> + else
> + return 0;
> +}
> +
> +static CORE_ADDR
> +win32_stopped_data_address (void)
> +{
> + if (the_low_target.stopped_data_address != NULL)
> + return the_low_target.stopped_data_address ();
> + else
> + return 0;
> +}
> +
> +
> /* Transfer memory from/to the debugged process. */
> static int
> child_xfer_memory (CORE_ADDR memaddr, char *our, int len,
> @@ -1697,10 +1739,10 @@ static struct target_ops win32_target_op
> NULL,
> win32_request_interrupt,
> NULL,
> - NULL,
> - NULL,
> - NULL,
> - NULL,
> + win32_insert_watchpoint,
> + win32_remove_watchpoint,
> + win32_stopped_by_watchpoint,
> + win32_stopped_data_address,
> NULL,
> NULL,
> NULL,
> Index: win32-low.h
> ===================================================================
> RCS file: /cvs/src/src/gdb/gdbserver/win32-low.h,v
> retrieving revision 1.9
> diff -u -p -r1.9 win32-low.h
> --- win32-low.h 3 Jan 2009 05:57:57 -0000 1.9
> +++ win32-low.h 30 Apr 2009 01:23:29 -0000
> @@ -70,6 +70,13 @@ struct win32_target_ops
>
> const unsigned char *breakpoint;
> int breakpoint_len;
> +
> + /* Watchpoint related functions. See target.h for comments. */
> + int (*insert_watchpoint) (char type, CORE_ADDR addr, int len);
> + int (*remove_watchpoint) (char type, CORE_ADDR addr, int len);
> + int (*stopped_by_watchpoint) (void);
> + CORE_ADDR (*stopped_data_address) (void);
> +
> };
>
> extern struct win32_target_ops the_low_target;
>
^ permalink raw reply [flat|nested] 18+ messages in thread
* Re: [RFA] i386/amd64 h/w watchpoints in gdbserver
2009-05-18 23:11 ` Doug Evans
@ 2009-05-18 23:28 ` Doug Evans
2009-05-19 9:05 ` Pierre Muller
0 siblings, 1 reply; 18+ messages in thread
From: Doug Evans @ 2009-05-18 23:28 UTC (permalink / raw)
To: gdb-patches, muller
Oh, btw, yes I know it needs updating 'cus i386/amd64 gdbserver is now
biarch. :-)
That part is mechanical.
Is there anything that still needs discussing?
On Mon, May 18, 2009 at 4:11 PM, Doug Evans <dje@google.com> wrote:
> Ping.
>
> [for completeness sake, Pierre, I haven't forgotten about win32-i386-low.c. :-)]
>
> What can I do so that we can make some progress here?
>
> On Thu, Apr 30, 2009 at 12:18 AM, Doug Evans <dje@google.com> wrote:
>> Hi.
>>
>> I took Pierre's patch here
>> http://sourceware.org/ml/gdb-patches/2009-02/msg00206.html
>>
>> and added support for {i386,amd64}-linux.
>> Pierre, I _think_ I didn't break win32 support, but it is different
>> than what you originally wrote. Can you test it?
>>
>> This patch assumes the gdbserver memory leak fix has been applied:
>> http://sourceware.org/ml/gdb-patches/2009-04/msg00803.html
>>
>>
>> 2009-04-29 Pierre Muller <muller@ics.u-strasbg.fr>
>> Doug Evans <dje@google.com>
>>
>> * Makefile.in (SFILES): Add i386-low.c
>> (i386_low_h): Define.
>> (i386-low.o): Add dependencies.
>> (linux-i386-low.o): Add i386-low.h dependency.
>> (linux-x86-64-low.o): Ditto.
>> (win32-i386-low.o): Ditto.
>> * i386-low.c: New file.
>> * i386-low.h: New file.
>> * configure.srv (i[34567]86-*-cygwin*): Add i386-low.o to srv_tgtobj.
>> (i[34567]86-*-linux*, i[34567]86-*-mingw*, x86_64-*-linux*): Ditto.
>> * linux-i386-low.c: Include stddef.h, i386-low.h.
>> (arch_process_info): New struct.
>> (i386_linux_dr_get, i386_linux_dr_set): New functions.
>> (i386_dr_low_set_addr, i386_dr_low_set_control): New functions.
>> (i386_dr_low_get_status): New function.
>> (i386_insert_watchpoint, i386_remove_watchpoint): New functions.
>> (i386_stopped_by_watchpoint, i386_stopped_data_address): New functions.
>> (i386_linux_new_process, i386_linux_new_thread): New functions.
>> (the_low_target): Add entries for insert_watchpoint, remove_watchpoint,
>> stopped_by_watchpoint, stopped_data_address, new_process, new_thread.
>> * linux-low.c (linux_add_process): Initialize arch_private.
>> (linux_remove_process): Free arch_private.
>> (notify_low_target_new_thread): New function.
>> (handle_extended_wait): Call it.
>> (linux_attach_lwp_1, linux_wait_1): Ditto.
>> (linux_insert_watchpoint): Update call to
>> the_low_target.insert_watchpoint.
>> (linux_remove_watchpoint): Update call to
>> the_low_target.remove_watchpoint.
>> (linux_stopped_by_watchpoint): Update call to
>> the_low_target.stopped_by_watchpoint.
>> (linux_stopped_data_address): Update call to
>> the_low_target.stopped_data_address.
>> * linux-low.h (process_info_private): New member arch_private.
>> (linux_target_ops): Add arch_private parameter to insert_watchpoint,
>> remove_watchpoint, stopped_by_watchpoint, stopped_data_address.
>> New members new_process, new_thread.
>> (ptid_of, PIDGET, TIDGET): New macros.
>> * linux-x86-64-low.c: Include stddef.h, i386-low.h.
>> (arch_process_info): New struct.
>> (x86_64_linux_dr_get, x86_64_linux_dr_set): New functions.
>> (i386_dr_low_set_addr, i386_dr_low_set_control): New functions.
>> (i386_dr_low_get_status): New function.
>> (x86_64_insert_watchpoint, x86_64_remove_watchpoint): New functions.
>> (x86_64_stopped_by_watchpoint): New function.
>> (x86_64_stopped_data_address): New function.
>> (x86_64_linux_new_process, x86_64_linux_new_thread): New functions.
>> (the_low_target): Add entries for insert_watchpoint, remove_watchpoint,
>> stopped_by_watchpoint, stopped_data_address, new_process, new_thread.
>> * server.h (paddr): Declare.
>> * utils.c (NUMCELLS, CELLSIZE): New macros.
>> (get_sell, xsnprintf, paddr): New functions.
>> * win32-arm-low.c (the_low_target): Add entries for insert_watchpoint,
>> remove_watchpoint, stopped_by_watchpoint, stopped_data_address.
>> * win32-i386-low.c: Include i386-low.h.
>> (i386_dr_low_set_addr, i386_dr_low_set_control): New functions.
>> (i386_dr_low_get_status): New function.
>> (the_low_target): Add entries for insert_watchpoint,
>> remove_watchpoint, stopped_by_watchpoint, stopped_data_address.
>> * win32-low.c (win32_insert_watchpoint): New function.
>> (win32_remove_watchpoint): New function.
>> (win32_stopped_by_watchpoint): New function.
>> (win32_stopped_data_address): New function.
>> (win32_target_ops): Add entries for insert_watchpoint,
>> remove_watchpoint, stopped_by_watchpoint, stopped_data_address.
>> * win32-low.h (win32_target_ops): New members insert_watchpoint,
>> remove_watchpoint, stopped_by_watchpoint, stopped_data_address.
>>
>> Index: Makefile.in
>> ===================================================================
>> RCS file: /cvs/src/src/gdb/gdbserver/Makefile.in,v
>> retrieving revision 1.73
>> diff -u -p -r1.73 Makefile.in
>> --- Makefile.in 1 Apr 2009 22:48:05 -0000 1.73
>> +++ Makefile.in 30 Apr 2009 01:23:29 -0000
>> @@ -104,7 +104,7 @@ SFILES= $(srcdir)/gdbreplay.c $(srcdir)/
>> $(srcdir)/thread-db.c $(srcdir)/utils.c \
>> $(srcdir)/linux-arm-low.c $(srcdir)/linux-cris-low.c \
>> $(srcdir)/linux-crisv32-low.c $(srcdir)/linux-i386-low.c \
>> - $(srcdir)/i387-fp.c \
>> + ${srcdir}/i386-low.c $(srcdir)/i387-fp.c \
>> $(srcdir)/linux-ia64-low.c $(srcdir)/linux-low.c \
>> $(srcdir)/linux-m32r-low.c \
>> $(srcdir)/linux-m68k-low.c $(srcdir)/linux-mips-low.c \
>> @@ -287,6 +287,10 @@ signals.o: ../common/signals.c $(server_
>> memmem.o: ../gnulib/memmem.c
>> $(CC) -o memmem.o -c $(CPPFLAGS) $(INTERNAL_CFLAGS) $<
>>
>> +i386_low_h = $(srcdir)/i386-low.h
>> +
>> +i386-low.o: i386-low.c $(i386_low_h) $(server_h) $(target_h)
>> +
>> i387-fp.o: i387-fp.c $(server_h)
>>
>> linux-low.o: linux-low.c $(linux_low_h) $(server_h)
>> @@ -297,7 +301,7 @@ linux-arm-low.o: linux-arm-low.c $(linux
>> linux-cris-low.o: linux-cris-low.c $(linux_low_h) $(server_h)
>> linux-crisv32-low.o: linux-crisv32-low.c $(linux_low_h) $(server_h)
>> linux-i386-low.o: linux-i386-low.c $(linux_low_h) $(server_h) \
>> - $(gdb_proc_service_h)
>> + $(gdb_proc_service_h) $(i386_low_h)
>> linux-ia64-low.o: linux-ia64-low.c $(linux_low_h) $(server_h)
>> linux-m32r-low.o: linux-m32r-low.c $(linux_low_h) $(server_h)
>> linux-mips-low.o: linux-mips-low.c $(linux_low_h) $(server_h) \
>> @@ -306,7 +310,7 @@ linux-ppc-low.o: linux-ppc-low.c $(linux
>> linux-s390-low.o: linux-s390-low.c $(linux_low_h) $(server_h)
>> linux-sh-low.o: linux-sh-low.c $(linux_low_h) $(server_h)
>> linux-x86-64-low.o: linux-x86-64-low.c $(linux_low_h) $(server_h) \
>> - $(gdb_proc_service_h)
>> + $(gdb_proc_service_h) $(i386_low_h)
>> linux-xtensa-low.o: linux-xtensa-low.c xtensa-xtregs.c $(linux_low_h) $(server_h)
>>
>> win32_low_h = $(srcdir)/win32-low.h
>> @@ -314,7 +318,7 @@ win32_low_h = $(srcdir)/win32-low.h
>> win32-low.o: win32-low.c $(win32_low_h) $(server_h) $(regdef_h) $(regcache_h)
>>
>> win32-arm-low.o: win32-arm-low.c $(win32_low_h) $(server_h)
>> -win32-i386-low.o: win32-i386-low.c $(win32_low_h) $(server_h)
>> +win32-i386-low.o: win32-i386-low.c $(win32_low_h) $(server_h) $(i386_low_h)
>>
>> spu-low.o: spu-low.c $(server_h)
>>
>> Index: configure.srv
>> ===================================================================
>> RCS file: /cvs/src/src/gdb/gdbserver/configure.srv,v
>> retrieving revision 1.40
>> diff -u -p -r1.40 configure.srv
>> --- configure.srv 19 Apr 2009 17:54:52 -0000 1.40
>> +++ configure.srv 30 Apr 2009 01:23:29 -0000
>> @@ -53,10 +53,10 @@ case "${target}" in
>> srv_linux_thread_db=yes
>> ;;
>> i[34567]86-*-cygwin*) srv_regobj=reg-i386.o
>> - srv_tgtobj="win32-low.o win32-i386-low.o"
>> + srv_tgtobj="i386-low.o win32-low.o win32-i386-low.o"
>> ;;
>> i[34567]86-*-linux*) srv_regobj=reg-i386-linux.o
>> - srv_tgtobj="linux-low.o linux-i386-low.o i387-fp.o"
>> + srv_tgtobj="linux-low.o linux-i386-low.o i386-low.o i387-fp.o"
>> srv_linux_usrregs=yes
>> srv_linux_regsets=yes
>> srv_linux_thread_db=yes
>> @@ -71,7 +71,7 @@ case "${target}" in
>> srv_mingwce=yes
>> ;;
>> i[34567]86-*-mingw*) srv_regobj=reg-i386.o
>> - srv_tgtobj="win32-low.o win32-i386-low.o"
>> + srv_tgtobj="i386-low.o win32-low.o win32-i386-low.o"
>> srv_mingw=yes
>> ;;
>> ia64-*-linux*) srv_regobj=reg-ia64.o
>> @@ -170,7 +170,7 @@ case "${target}" in
>> srv_tgtobj="spu-low.o"
>> ;;
>> x86_64-*-linux*) srv_regobj=reg-x86-64-linux.o
>> - srv_tgtobj="linux-low.o linux-x86-64-low.o i387-fp.o"
>> + srv_tgtobj="linux-low.o linux-x86-64-low.o i386-low.o i387-fp.o"
>> srv_linux_regsets=yes
>> srv_linux_thread_db=yes
>> ;;
>> Index: i386-low.c
>> ===================================================================
>> RCS file: i386-low.c
>> diff -N i386-low.c
>> --- /dev/null 1 Jan 1970 00:00:00 -0000
>> +++ i386-low.c 30 Apr 2009 01:23:29 -0000
>> @@ -0,0 +1,667 @@
>> +/* Debug register code for the i386.
>> +
>> + Copyright (C) 2009
>> + Free Software Foundation, Inc.
>> +
>> + This file is part of GDB.
>> +
>> + This program is free software; you can redistribute it and/or modify
>> + it under the terms of the GNU General Public License as published by
>> + the Free Software Foundation; either version 3 of the License, or
>> + (at your option) any later version.
>> +
>> + This program is distributed in the hope that it will be useful,
>> + but WITHOUT ANY WARRANTY; without even the implied warranty of
>> + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
>> + GNU General Public License for more details.
>> +
>> + You should have received a copy of the GNU General Public License
>> + along with this program. If not, see <http://www.gnu.org/licenses/>. */
>> +
>> +#include "server.h"
>> +#include "target.h"
>> +#include "i386-low.h"
>> +
>> +/* Support for 8-byte wide hw watchpoints. */
>> +#ifndef TARGET_HAS_DR_LEN_8
>> +#define TARGET_HAS_DR_LEN_8 (sizeof (long) == 8)
>> +#endif
>> +
>> +enum target_hw_bp_type
>> + {
>> + hw_write = 0, /* Common HW watchpoint */
>> + hw_read = 1, /* Read HW watchpoint */
>> + hw_access = 2, /* Access HW watchpoint */
>> + hw_execute = 3 /* Execute HW breakpoint */
>> + };
>> +
>> +/* DR7 Debug Control register fields. */
>> +
>> +/* How many bits to skip in DR7 to get to R/W and LEN fields. */
>> +#define DR_CONTROL_SHIFT 16
>> +/* How many bits in DR7 per R/W and LEN field for each watchpoint. */
>> +#define DR_CONTROL_SIZE 4
>> +
>> +/* Watchpoint/breakpoint read/write fields in DR7. */
>> +#define DR_RW_EXECUTE (0x0) /* Break on instruction execution. */
>> +#define DR_RW_WRITE (0x1) /* Break on data writes. */
>> +#define DR_RW_READ (0x3) /* Break on data reads or writes. */
>> +
>> +/* This is here for completeness. No platform supports this
>> + functionality yet (as of March 2001). Note that the DE flag in the
>> + CR4 register needs to be set to support this. */
>> +#ifndef DR_RW_IORW
>> +#define DR_RW_IORW (0x2) /* Break on I/O reads or writes. */
>> +#endif
>> +
>> +/* Watchpoint/breakpoint length fields in DR7. The 2-bit left shift
>> + is so we could OR this with the read/write field defined above. */
>> +#define DR_LEN_1 (0x0 << 2) /* 1-byte region watch or breakpoint. */
>> +#define DR_LEN_2 (0x1 << 2) /* 2-byte region watch. */
>> +#define DR_LEN_4 (0x3 << 2) /* 4-byte region watch. */
>> +#define DR_LEN_8 (0x2 << 2) /* 8-byte region watch (AMD64). */
>> +
>> +/* Local and Global Enable flags in DR7.
>> +
>> + When the Local Enable flag is set, the breakpoint/watchpoint is
>> + enabled only for the current task; the processor automatically
>> + clears this flag on every task switch. When the Global Enable flag
>> + is set, the breakpoint/watchpoint is enabled for all tasks; the
>> + processor never clears this flag.
>> +
>> + Currently, all watchpoint are locally enabled. If you need to
>> + enable them globally, read the comment which pertains to this in
>> + i386_insert_aligned_watchpoint below. */
>> +#define DR_LOCAL_ENABLE_SHIFT 0 /* Extra shift to the local enable bit. */
>> +#define DR_GLOBAL_ENABLE_SHIFT 1 /* Extra shift to the global enable bit. */
>> +#define DR_ENABLE_SIZE 2 /* Two enable bits per debug register. */
>> +
>> +/* Local and global exact breakpoint enable flags (a.k.a. slowdown
>> + flags). These are only required on i386, to allow detection of the
>> + exact instruction which caused a watchpoint to break; i486 and
>> + later processors do that automatically. We set these flags for
>> + backwards compatibility. */
>> +#define DR_LOCAL_SLOWDOWN (0x100)
>> +#define DR_GLOBAL_SLOWDOWN (0x200)
>> +
>> +/* Fields reserved by Intel. This includes the GD (General Detect
>> + Enable) flag, which causes a debug exception to be generated when a
>> + MOV instruction accesses one of the debug registers.
>> +
>> + FIXME: My Intel manual says we should use 0xF800, not 0xFC00. */
>> +#define DR_CONTROL_RESERVED (0xFC00)
>> +
>> +/* Auxiliary helper macros. */
>> +
>> +/* A value that masks all fields in DR7 that are reserved by Intel. */
>> +#define I386_DR_CONTROL_MASK (~DR_CONTROL_RESERVED)
>> +
>> +/* The I'th debug register is vacant if its Local and Global Enable
>> + bits are reset in the Debug Control register. */
>> +#define I386_DR_VACANT(state, i) \
>> + (((state)->dr_control_mirror & (3 << (DR_ENABLE_SIZE * (i)))) == 0)
>> +
>> +/* Locally enable the break/watchpoint in the I'th debug register. */
>> +#define I386_DR_LOCAL_ENABLE(state, i) \
>> + do { \
>> + (state)->dr_control_mirror |= \
>> + (1 << (DR_LOCAL_ENABLE_SHIFT + DR_ENABLE_SIZE * (i))); \
>> + } while (0)
>> +
>> +/* Globally enable the break/watchpoint in the I'th debug register. */
>> +#define I386_DR_GLOBAL_ENABLE(state, i) \
>> + do { \
>> + (state)->dr_control_mirror |= \
>> + (1 << (DR_GLOBAL_ENABLE_SHIFT + DR_ENABLE_SIZE * (i))); \
>> + } while (0)
>> +
>> +/* Disable the break/watchpoint in the I'th debug register. */
>> +#define I386_DR_DISABLE(state, i) \
>> + do { \
>> + (state)->dr_control_mirror &= \
>> + ~(3 << (DR_ENABLE_SIZE * (i))); \
>> + } while (0)
>> +
>> +/* Set in DR7 the RW and LEN fields for the I'th debug register. */
>> +#define I386_DR_SET_RW_LEN(state, i,rwlen) \
>> + do { \
>> + (state)->dr_control_mirror &= \
>> + ~(0x0f << (DR_CONTROL_SHIFT+DR_CONTROL_SIZE*(i))); \
>> + (state)->dr_control_mirror |= \
>> + ((rwlen) << (DR_CONTROL_SHIFT+DR_CONTROL_SIZE*(i))); \
>> + } while (0)
>> +
>> +/* Get from DR7 the RW and LEN fields for the I'th debug register. */
>> +#define I386_DR_GET_RW_LEN(state, i) \
>> + (((state)->dr_control_mirror >> (DR_CONTROL_SHIFT + DR_CONTROL_SIZE * (i))) & 0x0f)
>> +
>> +/* Did the watchpoint whose address is in the I'th register break? */
>> +#define I386_DR_WATCH_HIT(state,i) ((state)->dr_status_mirror & (1 << (i)))
>> +
>> +/* A macro to loop over all debug registers. */
>> +#define ALL_DEBUG_REGISTERS(i) for (i = 0; i < DR_NADDR; i++)
>> +
>> +/* Whether or not to print the mirrored debug registers. */
>> +static int maint_show_dr = 0;
>> +
>> +/* Types of operations supported by i386_handle_nonaligned_watchpoint. */
>> +typedef enum { WP_INSERT, WP_REMOVE, WP_COUNT } i386_wp_op_t;
>> +
>> +/* Internal functions. */
>> +
>> +/* Return the value of a 4-bit field for DR7 suitable for watching a
>> + region of LEN bytes for accesses of type TYPE. LEN is assumed to
>> + have the value of 1, 2, or 4. */
>> +static unsigned i386_length_and_rw_bits (int len, enum target_hw_bp_type type);
>> +
>> +/* Insert a watchpoint at address ADDR, which is assumed to be aligned
>> + according to the length of the region to watch. LEN_RW_BITS is the
>> + value of the bit-field from DR7 which describes the length and
>> + access type of the region to be watched by this watchpoint. Return
>> + 0 on success, -1 on failure. */
>> +static int i386_insert_aligned_watchpoint (struct i386_debug_reg_state *state,
>> + CORE_ADDR addr,
>> + unsigned len_rw_bits);
>> +
>> +/* Remove a watchpoint at address ADDR, which is assumed to be aligned
>> + according to the length of the region to watch. LEN_RW_BITS is the
>> + value of the bits from DR7 which describes the length and access
>> + type of the region watched by this watchpoint. Return 0 on
>> + success, -1 on failure. */
>> +static int i386_remove_aligned_watchpoint (struct i386_debug_reg_state *state,
>> + CORE_ADDR addr,
>> + unsigned len_rw_bits);
>> +
>> +/* Insert or remove a (possibly non-aligned) watchpoint, or count the
>> + number of debug registers required to watch a region at address
>> + ADDR whose length is LEN for accesses of type TYPE. Return 0 on
>> + successful insertion or removal, a positive number when queried
>> + about the number of registers, or -1 on failure. If WHAT is not a
>> + valid value, bombs through internal_error. */
>> +static int i386_handle_nonaligned_watchpoint (struct i386_debug_reg_state *state,
>> + i386_wp_op_t what,
>> + CORE_ADDR addr, int len,
>> + enum target_hw_bp_type type);
>> +
>> +/* Implementation. */
>> +
>> +/* Clear the reference counts and forget everything we knew about the
>> + debug registers. */
>> +
>> +void
>> +i386_low_cleanup_dregs (struct i386_debug_reg_state *state)
>> +{
>> + int i;
>> +
>> + ALL_DEBUG_REGISTERS(i)
>> + {
>> + state->dr_mirror[i] = 0;
>> + state->dr_ref_count[i] = 0;
>> + }
>> + state->dr_control_mirror = 0;
>> + state->dr_status_mirror = 0;
>> +}
>> +
>> +/* Print the values of the mirrored debug registers. This is called
>> + when maint_show_dr is non-zero. To set that up, type "maint
>> + show-debug-regs" at GDB's prompt. */
>> +
>> +static void
>> +i386_show_dr (struct i386_debug_reg_state *state,
>> + const char *func, CORE_ADDR addr,
>> + int len, enum target_hw_bp_type type)
>> +{
>> + int i;
>> +
>> + printf (func);
>> + if (addr || len)
>> + printf (" (addr=%lx, len=%d, type=%s)",
>> + (unsigned long) addr, len,
>> + type == hw_write ? "data-write"
>> + : (type == hw_read ? "data-read"
>> + : (type == hw_access ? "data-read/write"
>> + : (type == hw_execute ? "instruction-execute"
>> + /* FIXME: if/when I/O read/write
>> + watchpoints are supported, add them
>> + here. */
>> + : "??unknown??"))));
>> + printf (":\n");
>> + printf ("\tCONTROL (DR7): %08x STATUS (DR6): %08x\n",
>> + state->dr_control_mirror, state->dr_status_mirror);
>> + ALL_DEBUG_REGISTERS (i)
>> + {
>> + printf ("\
>> +\tDR%d: addr=0x%s, ref.count=%d DR%d: addr=0x%s, ref.count=%d\n",
>> + i, paddr (state->dr_mirror[i]), state->dr_ref_count[i],
>> + i+1, paddr (state->dr_mirror[i+1]), state->dr_ref_count[i+1]);
>> + i++;
>> + }
>> +}
>> +
>> +/* Return the value of a 4-bit field for DR7 suitable for watching a
>> + region of LEN bytes for accesses of type TYPE. LEN is assumed to
>> + have the value of 1, 2, or 4. */
>> +
>> +static unsigned
>> +i386_length_and_rw_bits (int len, enum target_hw_bp_type type)
>> +{
>> + unsigned rw;
>> +
>> + switch (type)
>> + {
>> + case hw_execute:
>> + rw = DR_RW_EXECUTE;
>> + break;
>> + case hw_write:
>> + rw = DR_RW_WRITE;
>> + break;
>> + case hw_read:
>> + /* The i386 doesn't support data-read watchpoints. */
>> + case hw_access:
>> + rw = DR_RW_READ;
>> + break;
>> +#if 0
>> + /* Not yet supported. */
>> + case hw_io_access:
>> + rw = DR_RW_IORW;
>> + break;
>> +#endif
>> + default:
>> + error ("\
>> +Invalid hardware breakpoint type %d in i386_length_and_rw_bits.\n",
>> + (int) type);
>> + }
>> +
>> + switch (len)
>> + {
>> + case 1:
>> + return (DR_LEN_1 | rw);
>> + case 2:
>> + return (DR_LEN_2 | rw);
>> + case 4:
>> + return (DR_LEN_4 | rw);
>> + case 8:
>> + if (TARGET_HAS_DR_LEN_8)
>> + return (DR_LEN_8 | rw);
>> + default:
>> + error ("\
>> +Invalid hardware breakpoint length %d in i386_length_and_rw_bits.\n", len);
>> + }
>> +}
>> +
>> +/* Insert a watchpoint at address ADDR, which is assumed to be aligned
>> + according to the length of the region to watch. LEN_RW_BITS is the
>> + value of the bits from DR7 which describes the length and access
>> + type of the region to be watched by this watchpoint. Return 0 on
>> + success, -1 on failure. */
>> +
>> +static int
>> +i386_insert_aligned_watchpoint (struct i386_debug_reg_state *state,
>> + CORE_ADDR addr, unsigned len_rw_bits)
>> +{
>> + int i;
>> +
>> + /* First, look for an occupied debug register with the same address
>> + and the same RW and LEN definitions. If we find one, we can
>> + reuse it for this watchpoint as well (and save a register). */
>> + ALL_DEBUG_REGISTERS(i)
>> + {
>> + if (!I386_DR_VACANT (state, i)
>> + && state->dr_mirror[i] == addr
>> + && I386_DR_GET_RW_LEN (state, i) == len_rw_bits)
>> + {
>> + state->dr_ref_count[i]++;
>> + return 0;
>> + }
>> + }
>> +
>> + /* Next, look for a vacant debug register. */
>> + ALL_DEBUG_REGISTERS(i)
>> + {
>> + if (I386_DR_VACANT (state, i))
>> + break;
>> + }
>> +
>> + /* No more debug registers! */
>> + if (i >= DR_NADDR)
>> + return -1;
>> +
>> + /* Now set up the register I to watch our region. */
>> +
>> + /* Record the info in our local mirrored array. */
>> + state->dr_mirror[i] = addr;
>> + state->dr_ref_count[i] = 1;
>> + I386_DR_SET_RW_LEN (state, i, len_rw_bits);
>> + /* Note: we only enable the watchpoint locally, i.e. in the current
>> + task. Currently, no i386 target allows or supports global
>> + watchpoints; however, if any target would want that in the
>> + future, GDB should probably provide a command to control whether
>> + to enable watchpoints globally or locally, and the code below
>> + should use global or local enable and slow-down flags as
>> + appropriate. */
>> + I386_DR_LOCAL_ENABLE (state, i);
>> + state->dr_control_mirror |= DR_LOCAL_SLOWDOWN;
>> + state->dr_control_mirror &= I386_DR_CONTROL_MASK;
>> +
>> + /* Finally, actually pass the info to the inferior. */
>> + i386_dr_low_set_addr (i, addr);
>> + i386_dr_low_set_control (state->dr_control_mirror);
>> +
>> + return 0;
>> +}
>> +
>> +/* Reset a watched address for debug reg DR.
>> + All implementations just do foo_set_addr (addr, 0), so this is a wrapper
>> + around foo_set_addr to maintain the concept that this is a reset. */
>> +
>> +static void
>> +i386_dr_low_reset_addr (int dr)
>> +{
>> + i386_dr_low_set_addr (dr, 0);
>> +}
>> +
>> +/* Remove a watchpoint at address ADDR, which is assumed to be aligned
>> + according to the length of the region to watch. LEN_RW_BITS is the
>> + value of the bits from DR7 which describes the length and access
>> + type of the region watched by this watchpoint. Return 0 on
>> + success, -1 on failure. */
>> +
>> +static int
>> +i386_remove_aligned_watchpoint (struct i386_debug_reg_state *state,
>> + CORE_ADDR addr, unsigned len_rw_bits)
>> +{
>> + int i, retval = -1;
>> +
>> + ALL_DEBUG_REGISTERS(i)
>> + {
>> + if (!I386_DR_VACANT (state, i)
>> + && state->dr_mirror[i] == addr
>> + && I386_DR_GET_RW_LEN (state, i) == len_rw_bits)
>> + {
>> + if (--state->dr_ref_count[i] == 0) /* no longer in use? */
>> + {
>> + /* Reset our mirror. */
>> + state->dr_mirror[i] = 0;
>> + I386_DR_DISABLE (state, i);
>> + /* Reset it in the inferior. */
>> + i386_dr_low_set_control (state->dr_control_mirror);
>> + i386_dr_low_reset_addr (i);
>> + }
>> + retval = 0;
>> + }
>> + }
>> +
>> + return retval;
>> +}
>> +
>> +/* Insert or remove a (possibly non-aligned) watchpoint, or count the
>> + number of debug registers required to watch a region at address
>> + ADDR whose length is LEN for accesses of type TYPE. Return 0 on
>> + successful insertion or removal, a positive number when queried
>> + about the number of registers, or -1 on failure. If WHAT is not a
>> + valid value, bombs through internal_error. */
>> +
>> +static int
>> +i386_handle_nonaligned_watchpoint (struct i386_debug_reg_state *state,
>> + i386_wp_op_t what, CORE_ADDR addr, int len,
>> + enum target_hw_bp_type type)
>> +{
>> + int retval = 0, status = 0;
>> + int max_wp_len = TARGET_HAS_DR_LEN_8 ? 8 : 4;
>> +
>> + static int size_try_array[8][8] =
>> + {
>> + {1, 1, 1, 1, 1, 1, 1, 1}, /* Trying size one. */
>> + {2, 1, 2, 1, 2, 1, 2, 1}, /* Trying size two. */
>> + {2, 1, 2, 1, 2, 1, 2, 1}, /* Trying size three. */
>> + {4, 1, 2, 1, 4, 1, 2, 1}, /* Trying size four. */
>> + {4, 1, 2, 1, 4, 1, 2, 1}, /* Trying size five. */
>> + {4, 1, 2, 1, 4, 1, 2, 1}, /* Trying size six. */
>> + {4, 1, 2, 1, 4, 1, 2, 1}, /* Trying size seven. */
>> + {8, 1, 2, 1, 4, 1, 2, 1}, /* Trying size eight. */
>> + };
>> +
>> + while (len > 0)
>> + {
>> + int align = addr % max_wp_len;
>> + /* Four (eight on AMD64) is the maximum length a debug register
>> + can watch. */
>> + int try = (len > max_wp_len ? (max_wp_len - 1) : len - 1);
>> + int size = size_try_array[try][align];
>> +
>> + if (what == WP_COUNT)
>> + {
>> + /* size_try_array[] is defined such that each iteration
>> + through the loop is guaranteed to produce an address and a
>> + size that can be watched with a single debug register.
>> + Thus, for counting the registers required to watch a
>> + region, we simply need to increment the count on each
>> + iteration. */
>> + retval++;
>> + }
>> + else
>> + {
>> + unsigned len_rw = i386_length_and_rw_bits (size, type);
>> +
>> + if (what == WP_INSERT)
>> + status = i386_insert_aligned_watchpoint (state, addr, len_rw);
>> + else if (what == WP_REMOVE)
>> + status = i386_remove_aligned_watchpoint (state, addr, len_rw);
>> +#if 0
>> + else
>> + internal_error (__FILE__, __LINE__, _("\
>> +Invalid value %d of operation in i386_handle_nonaligned_watchpoint.\n"),
>> + (int)what);
>> +#endif
>> + /* We keep the loop going even after a failure, because some
>> + of the other aligned watchpoints might still succeed
>> + (e.g. if they watch addresses that are already watched,
>> + in which case we just increment the reference counts of
>> + occupied debug registers). If we break out of the loop
>> + too early, we could cause those addresses watched by
>> + other watchpoints to be disabled when breakpoint.c reacts
>> + to our failure to insert this watchpoint and tries to
>> + remove it. */
>> + if (status)
>> + retval = status;
>> + }
>> +
>> + addr += size;
>> + len -= size;
>> + }
>> +
>> + return retval;
>> +}
>> +
>> +#define Z_PACKET_WRITE_WP '2'
>> +#define Z_PACKET_READ_WP '3'
>> +#define Z_PACKET_ACCESS_WP '4'
>> +
>> +static int
>> +Z_packet_to_hw_type (char type)
>> +{
>> + switch (type)
>> + {
>> + case Z_PACKET_WRITE_WP: return hw_write;
>> + case Z_PACKET_READ_WP: return hw_read;
>> + case Z_PACKET_ACCESS_WP: return hw_access;
>> + default:
>> + error ("Z_packet_to_hw_type: bad watchpoint type %c", type);
>> + }
>> +}
>> +
>> +/* Insert a watchpoint to watch a memory region which starts at
>> + address ADDR and whose length is LEN bytes. Watch memory accesses
>> + of the type TYPE_FROM_PACKET. Return 0 on success, -1 on failure. */
>> +
>> +int
>> +i386_low_insert_watchpoint (struct i386_debug_reg_state *state,
>> + char type_from_packet, CORE_ADDR addr, int len)
>> +{
>> + int retval;
>> + int type = Z_packet_to_hw_type (type_from_packet);
>> +
>> + if (((len != 1 && len !=2 && len !=4) && !(TARGET_HAS_DR_LEN_8 && len == 8))
>> + || addr % len != 0)
>> + {
>> + retval = i386_handle_nonaligned_watchpoint (state, WP_INSERT,
>> + addr, len, type);
>> + }
>> + else
>> + {
>> + unsigned len_rw = i386_length_and_rw_bits (len, type);
>> +
>> + retval = i386_insert_aligned_watchpoint (state, addr, len_rw);
>> + }
>> +
>> + if (maint_show_dr)
>> + i386_show_dr (state, "insert_watchpoint", addr, len, type);
>> +
>> + return retval;
>> +}
>> +
>> +/* Remove a watchpoint that watched the memory region which starts at
>> + address ADDR, whose length is LEN bytes, and for accesses of the
>> + type TYPE_FROM_PACKET. Return 0 on success, -1 on failure. */
>> +
>> +int
>> +i386_low_remove_watchpoint (struct i386_debug_reg_state *state,
>> + char type_from_packet, CORE_ADDR addr, int len)
>> +{
>> + int retval;
>> + int type = Z_packet_to_hw_type (type_from_packet);
>> +
>> + if (((len != 1 && len !=2 && len !=4) && !(TARGET_HAS_DR_LEN_8 && len == 8))
>> + || addr % len != 0)
>> + {
>> + retval = i386_handle_nonaligned_watchpoint (state, WP_REMOVE,
>> + addr, len, type);
>> + }
>> + else
>> + {
>> + unsigned len_rw = i386_length_and_rw_bits (len, type);
>> +
>> + retval = i386_remove_aligned_watchpoint (state, addr, len_rw);
>> + }
>> + if (maint_show_dr)
>> + i386_show_dr (state, "remove_watchpoint", addr, len, type);
>> + return retval;
>> +}
>> +
>> +/* Return non-zero if we can watch a memory region that starts at
>> + address ADDR and whose length is LEN bytes. */
>> +
>> +int
>> +i386_low_region_ok_for_watchpoint (struct i386_debug_reg_state *state,
>> + CORE_ADDR addr, int len)
>> +{
>> + int nregs;
>> +
>> + /* Compute how many aligned watchpoints we would need to cover this
>> + region. */
>> + nregs = i386_handle_nonaligned_watchpoint (state, WP_COUNT,
>> + addr, len, hw_write);
>> + return nregs <= DR_NADDR ? 1 : 0;
>> +}
>> +
>> +/* If the inferior has some watchpoint that triggered, set the
>> + address associated with that watchpoint and return non-zero.
>> + Otherwise, return zero. */
>> +
>> +CORE_ADDR
>> +i386_low_stopped_data_address (struct i386_debug_reg_state *state)
>> +{
>> + CORE_ADDR addr = 0;
>> + int i;
>> + int rc = 0;
>> +
>> + state->dr_status_mirror = i386_dr_low_get_status ();
>> +
>> + ALL_DEBUG_REGISTERS(i)
>> + {
>> + if (I386_DR_WATCH_HIT (state, i)
>> + /* This second condition makes sure DRi is set up for a data
>> + watchpoint, not a hardware breakpoint. The reason is
>> + that GDB doesn't call the target_stopped_data_address
>> + method except for data watchpoints. In other words, I'm
>> + being paranoiac. */
>> + && I386_DR_GET_RW_LEN (state, i) != 0)
>> + {
>> + addr = state->dr_mirror[i];
>> + rc = 1;
>> + if (maint_show_dr)
>> + i386_show_dr (state, "watchpoint_hit", addr, -1, hw_write);
>> + }
>> + }
>> + if (maint_show_dr && addr == 0)
>> + i386_show_dr (state, "stopped_data_addr", 0, 0, hw_write);
>> +
>> + /* NOTE: gdb version checks rc != 0 here. */
>> + return addr;
>> +}
>> +
>> +int
>> +i386_low_stopped_by_watchpoint (struct i386_debug_reg_state *state)
>> +{
>> + CORE_ADDR addr = 0;
>> + /* NOTE: gdb version passes boolean found/not-found result from
>> + i386_stopped_data_address. */
>> + addr = i386_low_stopped_data_address (state);
>> + return (addr != 0);
>> +}
>> +
>> +/* Support for h/w breakpoints.
>> + This support is not currently used, kept for reference. */
>> +
>> +/* Return non-zero if the inferior has some break/watchpoint that
>> + triggered. */
>> +
>> +int
>> +i386_low_stopped_by_hwbp (struct i386_debug_reg_state *state)
>> +{
>> + int i;
>> +
>> + state->dr_status_mirror = i386_dr_low_get_status ();
>> + if (maint_show_dr)
>> + i386_show_dr (state, "stopped_by_hwbp", 0, 0, hw_execute);
>> +
>> + ALL_DEBUG_REGISTERS(i)
>> + {
>> + if (I386_DR_WATCH_HIT (state, i))
>> + return 1;
>> + }
>> +
>> + return 0;
>> +}
>> +
>> +/* Insert a hardware-assisted breakpoint at ADDR.
>> + Return 0 on success, -1 on failure. */
>> +
>> +int
>> +i386_low_insert_hw_breakpoint (struct i386_debug_reg_state *state,
>> + CORE_ADDR addr)
>> +{
>> + unsigned len_rw = i386_length_and_rw_bits (1, hw_execute);
>> + int retval = i386_insert_aligned_watchpoint (state, addr, len_rw);
>> +
>> + if (maint_show_dr)
>> + i386_show_dr (state, "insert_hwbp", addr, 1, hw_execute);
>> +
>> + return retval;
>> +}
>> +
>> +/* Remove a hardware-assisted breakpoint at ADDR.
>> + Return 0 on success, -1 on failure. */
>> +
>> +int
>> +i386_low_remove_hw_breakpoint (struct i386_debug_reg_state *state,
>> + CORE_ADDR addr)
>> +{
>> + unsigned len_rw = i386_length_and_rw_bits (1, hw_execute);
>> + int retval = i386_remove_aligned_watchpoint (state, addr, len_rw);
>> +
>> + if (maint_show_dr)
>> + i386_show_dr (state, "remove_hwbp", addr, 1, hw_execute);
>> +
>> + return retval;
>> +}
>> Index: i386-low.h
>> ===================================================================
>> RCS file: i386-low.h
>> diff -N i386-low.h
>> --- /dev/null 1 Jan 1970 00:00:00 -0000
>> +++ i386-low.h 30 Apr 2009 01:23:29 -0000
>> @@ -0,0 +1,118 @@
>> +/* Misc. low level support for i386.
>> +
>> + Copyright (C) 2009
>> + Free Software Foundation, Inc.
>> +
>> + This file is part of GDB.
>> +
>> + This program is free software; you can redistribute it and/or modify
>> + it under the terms of the GNU General Public License as published by
>> + the Free Software Foundation; either version 3 of the License, or
>> + (at your option) any later version.
>> +
>> + This program is distributed in the hope that it will be useful,
>> + but WITHOUT ANY WARRANTY; without even the implied warranty of
>> + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
>> + GNU General Public License for more details.
>> +
>> + You should have received a copy of the GNU General Public License
>> + along with this program. If not, see <http://www.gnu.org/licenses/>. */
>> +
>> +/* Support for hardware watchpoints and breakpoints using the i386
>> + debug registers.
>> +
>> + This provides several functions for inserting and removing
>> + hardware-assisted breakpoints and watchpoints, testing if one or
>> + more of the watchpoints triggered and at what address, checking
>> + whether a given region can be watched, etc.
>> +
>> + The functions below implement debug registers sharing by reference
>> + counts, and allow to watch regions up to 16 bytes long
>> + (32 bytes on 64 bit hosts). */
>> +
>> +
>> +/* Debug registers' indices. */
>> +#define DR_FIRSTADDR 0
>> +#define DR_LASTADDR 3
>> +#define DR_NADDR 4 /* The number of debug address registers. */
>> +#define DR_STATUS 6
>> +#define DR_CONTROL 7
>> +
>> +/* Global state needed to track h/w watchpoints. */
>> +
>> +struct i386_debug_reg_state
>> +{
>> + /* Mirror the inferior's DRi registers. We keep the status and
>> + control registers separated because they don't hold addresses. */
>> + CORE_ADDR dr_mirror[DR_NADDR];
>> + unsigned dr_status_mirror, dr_control_mirror;
>> +
>> + /* Reference counts for each debug register. */
>> + int dr_ref_count[DR_NADDR];
>> +};
>> +
>> +/* Clear the reference counts and forget everything we knew about DRi. */
>> +extern void i386_low_cleanup_dregs (struct i386_debug_reg_state *state);
>> +
>> +/* Insert a watchpoint to watch a memory region which starts at
>> + address ADDR and whose length is LEN bytes. Watch memory accesses
>> + of the type TYPE_FROM_PACKET. Return 0 on success, -1 on failure. */
>> +extern int i386_low_insert_watchpoint (struct i386_debug_reg_state *state,
>> + char type_from_packet, CORE_ADDR addr,
>> + int len);
>> +
>> +/* Remove a watchpoint that watched the memory region which starts at
>> + address ADDR, whose length is LEN bytes, and for accesses of the
>> + type TYPE_FROM_PACKET. Return 0 on success, -1 on failure. */
>> +extern int i386_low_remove_watchpoint (struct i386_debug_reg_state *state,
>> + char type_from_packet, CORE_ADDR addr,
>> + int len);
>> +
>> +/* Return non-zero if we can watch a memory region that starts at
>> + address ADDR and whose length is LEN bytes. */
>> +extern int i386_low_region_ok_for_watchpoint (struct i386_debug_reg_state *state,
>> + CORE_ADDR addr, int len);
>> +
>> +/* If the inferior has some break/watchpoint that triggered, set
>> + the address associated with that break/watchpoint and return
>> + true. Otherwise, return false. */
>> +extern CORE_ADDR i386_low_stopped_data_address (struct i386_debug_reg_state *state);
>> +
>> +extern int i386_low_stopped_by_watchpoint (struct i386_debug_reg_state *state);
>> +
>> +/* Return non-zero if the inferior has some break/watchpoint that
>> + triggered. */
>> +extern int i386_low_stopped_by_hwbp (struct i386_debug_reg_state *state);
>> +
>> +/* Insert a hardware-assisted breakpoint at ADDR.
>> + Return 0 on success, -1 on failure. */
>> +extern int i386_low_insert_hw_breakpoint (struct i386_debug_reg_state *state,
>> + CORE_ADDR addr);
>> +
>> +/* Remove a hardware-assisted breakpoint at ADDR.
>> + Return 0 on success, -1 on failure. */
>> +extern int i386_low_remove_hw_breakpoint (struct i386_debug_reg_state *state,
>> + CORE_ADDR addr);
>> +
>> +/* Each target needs to provide several low-level functions
>> + that will be called to insert watchpoints and hardware breakpoints
>> + into the inferior, remove them, and check their status. These
>> + functions are:
>> +
>> + i386_dr_low_set_control -- set the debug control (DR7)
>> + register to a given value
>> +
>> + i386_dr_low_set_addr -- put an address into one debug register
>> +
>> + i386_dr_low_get_status -- return the value of the debug
>> + status (DR6) register.
>> +*/
>> +
>> +/* Pass the address ADDR to the inferior in the I'th debug register. */
>> +extern void i386_dr_low_set_addr (int i, CORE_ADDR addr);
>> +
>> +/* Pass the value VAL to the inferior in the DR7 debug control register. */
>> +extern void i386_dr_low_set_control (unsigned val);
>> +
>> +/* Get the value of the DR6 debug status register from the inferior. */
>> +extern unsigned i386_dr_low_get_status (void);
>> Index: linux-i386-low.c
>> ===================================================================
>> RCS file: /cvs/src/src/gdb/gdbserver/linux-i386-low.c,v
>> retrieving revision 1.19
>> diff -u -p -r1.19 linux-i386-low.c
>> --- linux-i386-low.c 22 Mar 2009 23:57:10 -0000 1.19
>> +++ linux-i386-low.c 30 Apr 2009 01:23:29 -0000
>> @@ -17,9 +17,11 @@
>> You should have received a copy of the GNU General Public License
>> along with this program. If not, see <http://www.gnu.org/licenses/>. */
>>
>> +#include <stddef.h>
>> #include "server.h"
>> #include "linux-low.h"
>> #include "i387-fp.h"
>> +#include "i386-low.h"
>>
>> #include "gdb_proc_service.h"
>>
>> @@ -33,10 +35,14 @@
>> #define PTRACE_GET_THREAD_AREA 25
>> #endif
>>
>> +struct arch_process_info
>> +{
>> + struct i386_debug_reg_state debug_reg_state;
>> +};
>> +
>> /* Defined in auto-generated file reg-i386-linux.c. */
>> void init_registers_i386_linux (void);
>>
>> -
>> /* This module only supports access to the general purpose registers. */
>>
>> #define i386_num_regs 16
>> @@ -187,6 +193,148 @@ i386_breakpoint_at (CORE_ADDR pc)
>>
>> return 0;
>> }
>> +
>> +/* Support for debug registers. */
>> +
>> +static unsigned long
>> +i386_linux_dr_get (ptid_t ptid, int regnum)
>> +{
>> + int tid;
>> + unsigned long value;
>> +
>> + tid = TIDGET (ptid);
>> + if (tid == 0)
>> + tid = PIDGET (ptid);
>> +
>> + errno = 0;
>> + value = ptrace (PTRACE_PEEKUSER, tid,
>> + offsetof (struct user, u_debugreg[regnum]), 0);
>> + if (errno != 0)
>> + error ("Couldn't read debug register");
>> +
>> + return value;
>> +}
>> +
>> +static void
>> +i386_linux_dr_set (ptid_t ptid, int regnum, unsigned long value)
>> +{
>> + int tid;
>> +
>> + tid = TIDGET (ptid);
>> + if (tid == 0)
>> + tid = PIDGET (ptid);
>> +
>> + errno = 0;
>> + ptrace (PTRACE_POKEUSER, tid,
>> + offsetof (struct user, u_debugreg[regnum]), value);
>> + if (errno != 0)
>> + error ("Couldn't write debug register");
>> +}
>> +
>> +/* Pass the address ADDR to the inferior in debug register REGNUM. */
>> +
>> +void
>> +i386_dr_low_set_addr (int regnum, CORE_ADDR addr)
>> +{
>> + struct inferior_list_entry *lp;
>> +
>> + if (! (regnum >= 0 && regnum <= DR_LASTADDR - DR_FIRSTADDR))
>> + error ("Invalid debug register");
>> +
>> + for (lp = all_lwps.head; lp; lp = lp->next)
>> + {
>> + struct lwp_info *lwp = (struct lwp_info *) lp;
>> + i386_linux_dr_set (ptid_of (lwp), DR_FIRSTADDR + regnum, addr);
>> + }
>> +}
>> +
>> +/* Pass the value VAL to the inferior in the DR7 debug control register. */
>> +
>> +void
>> +i386_dr_low_set_control (unsigned control)
>> +{
>> + struct inferior_list_entry *lp;
>> +
>> + for (lp = all_lwps.head; lp; lp = lp->next)
>> + {
>> + struct lwp_info *lwp = (struct lwp_info *) lp;
>> + i386_linux_dr_set (ptid_of (lwp), DR_CONTROL, control);
>> + }
>> +}
>> +
>> +/* Get the value of the DR6 debug status register from the inferior. */
>> +
>> +unsigned
>> +i386_dr_low_get_status (void)
>> +{
>> + ptid_t inferior_ptid = ptid_of (get_thread_lwp (current_inferior));
>> + return i386_linux_dr_get (inferior_ptid, DR_STATUS);
>> +}
>> +
>> +/* Watchpoint support. */
>> +
>> +static int
>> +i386_insert_watchpoint (struct arch_process_info *arch_private,
>> + char type, CORE_ADDR addr, int len)
>> +{
>> + return i386_low_insert_watchpoint (&arch_private->debug_reg_state,
>> + type, addr, len);
>> +}
>> +
>> +static int
>> +i386_remove_watchpoint (struct arch_process_info *arch_private,
>> + char type, CORE_ADDR addr, int len)
>> +{
>> + return i386_low_remove_watchpoint (&arch_private->debug_reg_state,
>> + type, addr, len);
>> +}
>> +
>> +static int
>> +i386_stopped_by_watchpoint (struct arch_process_info *arch_private)
>> +{
>> + return i386_low_stopped_by_watchpoint (&arch_private->debug_reg_state);
>> +}
>> +
>> +static CORE_ADDR
>> +i386_stopped_data_address (struct arch_process_info *arch_private)
>> +{
>> + return i386_low_stopped_data_address (&arch_private->debug_reg_state);
>> +}
>> +
>> +/* Called when a new process is created. */
>> +
>> +struct arch_process_info *
>> +i386_linux_new_process (int pid, int attached)
>> +{
>> + struct arch_process_info *info = xcalloc (1, sizeof (*info));
>> +
>> + return info;
>> +}
>> +
>> +/* Called when a new thread is detected.
>> + INITIAL is non-zero for the main thread, zero otherwise. */
>> +
>> +static void
>> +i386_linux_new_thread (struct lwp_info *lwp, int initial)
>> +{
>> + /* The initial thread has debug regs set later during process
>> + creation/attaching handling. */
>> +
>> + if (! initial)
>> + {
>> + int i;
>> + ptid_t ptid = ptid_of (lwp);
>> + int pid = PIDGET (ptid);
>> + struct process_info *proc = find_process_pid (pid);
>> + struct arch_process_info *arch_private = proc->private->arch_private;
>> + struct i386_debug_reg_state *state = &arch_private->debug_reg_state;
>> +
>> + for (i = DR_FIRSTADDR; i <= DR_LASTADDR; i++)
>> + i386_linux_dr_set (ptid, i, state->dr_mirror[i]);
>> +
>> + i386_linux_dr_set (ptid, DR_CONTROL, state->dr_control_mirror);
>> + }
>> +}
>>
>> struct linux_target_ops the_low_target = {
>> init_registers_i386_linux,
>> @@ -201,10 +349,12 @@ struct linux_target_ops the_low_target =
>> NULL,
>> 1,
>> i386_breakpoint_at,
>> + i386_insert_watchpoint,
>> + i386_remove_watchpoint,
>> + i386_stopped_by_watchpoint,
>> + i386_stopped_data_address,
>> NULL,
>> NULL,
>> - NULL,
>> - NULL,
>> - NULL,
>> - NULL,
>> + i386_linux_new_process,
>> + i386_linux_new_thread
>> };
>> Index: linux-low.c
>> ===================================================================
>> RCS file: /cvs/src/src/gdb/gdbserver/linux-low.c,v
>> retrieving revision 1.97
>> diff -u -p -r1.97 linux-low.c
>> --- linux-low.c 3 Apr 2009 11:40:02 -0000 1.97
>> +++ linux-low.c 30 Apr 2009 06:26:54 -0000
>> @@ -120,6 +120,7 @@ static int must_set_ptrace_flags;
>> control of gdbserver have the same architecture. */
>> static int new_inferior;
>>
>> +static void notify_low_target_new_thread (struct lwp_info *lwp, int initial);
>> static void linux_resume_one_lwp (struct inferior_list_entry *entry,
>> int step, int signal, siginfo_t *info);
>> static void linux_resume (struct thread_resume *resume_info, size_t n);
>> @@ -179,6 +180,9 @@ linux_add_process (int pid, int attached
>> proc = add_process (pid, attached);
>> proc->private = xcalloc (1, sizeof (*proc->private));
>>
>> + if (the_low_target.new_process != NULL)
>> + proc->private->arch_private = the_low_target.new_process (pid, attached);
>> +
>> return proc;
>> }
>>
>> @@ -188,6 +192,7 @@ linux_add_process (int pid, int attached
>> static void
>> linux_remove_process (struct process_info *process)
>> {
>> + free (process->private->arch_private);
>> free (process->private);
>> remove_process (process);
>> }
>> @@ -231,6 +236,7 @@ handle_extended_wait (struct lwp_info *e
>> ptid = ptid_build (pid_of (event_child), new_pid, 0);
>> new_lwp = (struct lwp_info *) add_lwp (ptid);
>> add_thread (ptid, new_lwp);
>> + notify_low_target_new_thread (new_lwp, 0);
>>
>> /* Normally we will get the pending SIGSTOP. But in some cases
>> we might get another signal delivered to the group first.
>> @@ -313,6 +319,18 @@ add_lwp (ptid_t ptid)
>> return lwp;
>> }
>>
>> +/* Notify the backend that we have a new thread, be it the main thread
>> + or a later one.
>> + INITIAL is non-zero for the main thread, zero otherwise.
>> + NOTE: This must be called when the thread is stopped. */
>> +
>> +static void
>> +notify_low_target_new_thread (struct lwp_info *lwp, int initial)
>> +{
>> + if (the_low_target.new_thread != NULL)
>> + the_low_target.new_thread (lwp, initial);
>> +}
>> +
>> /* Start an inferior process and returns its pid.
>> ALLARGS is a vector of program-name and args. */
>>
>> @@ -354,6 +372,8 @@ linux_create_inferior (char *program, ch
>> ptid = ptid_build (pid, pid, 0);
>> new_lwp = add_lwp (ptid);
>> add_thread (ptid, new_lwp);
>> + /* We can't call notify_low_target_new_thread there, the thread isn't
>> + stopped. Piggyback on must_set_ptrace_flags and call it then. */
>> must_set_ptrace_flags = 1;
>>
>> return pid;
>> @@ -401,6 +421,7 @@ linux_attach_lwp_1 (unsigned long lwpid,
>>
>> new_lwp = (struct lwp_info *) add_lwp (ptid);
>> add_thread (ptid, new_lwp);
>> + notify_low_target_new_thread (new_lwp, initial);
>>
>> /* The next time we wait for this LWP we'll see a SIGSTOP as PTRACE_ATTACH
>> brings it to a halt.
>> @@ -1261,6 +1282,7 @@ retry:
>> if (must_set_ptrace_flags)
>> {
>> ptrace (PTRACE_SETOPTIONS, lwpid_of (lwp), 0, PTRACE_O_TRACECLONE);
>> + notify_low_target_new_thread (lwp, 1);
>> must_set_ptrace_flags = 0;
>> }
>> /* If we are waiting for a particular child, and it exited,
>> @@ -2599,7 +2623,11 @@ static int
>> linux_insert_watchpoint (char type, CORE_ADDR addr, int len)
>> {
>> if (the_low_target.insert_watchpoint != NULL)
>> - return the_low_target.insert_watchpoint (type, addr, len);
>> + {
>> + struct process_info *proc = current_process ();
>> + return the_low_target.insert_watchpoint (proc->private->arch_private,
>> + type, addr, len);
>> + }
>> else
>> /* Unsupported (see target.h). */
>> return 1;
>> @@ -2609,7 +2637,11 @@ static int
>> linux_remove_watchpoint (char type, CORE_ADDR addr, int len)
>> {
>> if (the_low_target.remove_watchpoint != NULL)
>> - return the_low_target.remove_watchpoint (type, addr, len);
>> + {
>> + struct process_info *proc = current_process ();
>> + return the_low_target.remove_watchpoint (proc->private->arch_private,
>> + type, addr, len);
>> + }
>> else
>> /* Unsupported (see target.h). */
>> return 1;
>> @@ -2619,7 +2651,10 @@ static int
>> linux_stopped_by_watchpoint (void)
>> {
>> if (the_low_target.stopped_by_watchpoint != NULL)
>> - return the_low_target.stopped_by_watchpoint ();
>> + {
>> + struct process_info *proc = current_process ();
>> + return the_low_target.stopped_by_watchpoint (proc->private->arch_private);
>> + }
>> else
>> return 0;
>> }
>> @@ -2628,7 +2663,10 @@ static CORE_ADDR
>> linux_stopped_data_address (void)
>> {
>> if (the_low_target.stopped_data_address != NULL)
>> - return the_low_target.stopped_data_address ();
>> + {
>> + struct process_info *proc = current_process ();
>> + return the_low_target.stopped_data_address (proc->private->arch_private);
>> + }
>> else
>> return 0;
>> }
>> Index: linux-low.h
>> ===================================================================
>> RCS file: /cvs/src/src/gdb/gdbserver/linux-low.h,v
>> retrieving revision 1.28
>> diff -u -p -r1.28 linux-low.h
>> --- linux-low.h 1 Apr 2009 22:50:24 -0000 1.28
>> +++ linux-low.h 30 Apr 2009 01:23:29 -0000
>> @@ -54,8 +54,13 @@ struct process_info_private
>>
>> /* Connection to the libthread_db library. */
>> td_thragent_t *thread_agent;
>> +
>> + /* Target-specific additions. */
>> + struct arch_process_info *arch_private;
>> };
>>
>> +struct lwp_info;
>> +
>> struct linux_target_ops
>> {
>> /* Architecture-specific setup. */
>> @@ -75,26 +80,37 @@ struct linux_target_ops
>> int breakpoint_len;
>> CORE_ADDR (*breakpoint_reinsert_addr) (void);
>>
>> -
>> int decr_pc_after_break;
>> int (*breakpoint_at) (CORE_ADDR pc);
>>
>> /* Watchpoint related functions. See target.h for comments. */
>> - int (*insert_watchpoint) (char type, CORE_ADDR addr, int len);
>> - int (*remove_watchpoint) (char type, CORE_ADDR addr, int len);
>> - int (*stopped_by_watchpoint) (void);
>> - CORE_ADDR (*stopped_data_address) (void);
>> + int (*insert_watchpoint) (struct arch_process_info *arch_private,
>> + char type, CORE_ADDR addr, int len);
>> + int (*remove_watchpoint) (struct arch_process_info *arch_private,
>> + char type, CORE_ADDR addr, int len);
>> + int (*stopped_by_watchpoint) (struct arch_process_info *arch_private);
>> + CORE_ADDR (*stopped_data_address) (struct arch_process_info *arch_private);
>>
>> /* Hooks to reformat register data for PEEKUSR/POKEUSR (in particular
>> for registers smaller than an xfer unit). */
>> void (*collect_ptrace_register) (int regno, char *buf);
>> void (*supply_ptrace_register) (int regno, const char *buf);
>> +
>> + /* Hook to call when a new process is created or attached to. */
>> + struct arch_process_info * (*new_process) (int pid, int attached);
>> +
>> + /* Hook to call when a new thread is detected.
>> + INITIAL is non-zero for the main thread, zero otherwise. */
>> + void (*new_thread) (struct lwp_info *, int initial);
>> };
>>
>> extern struct linux_target_ops the_low_target;
>>
>> +#define ptid_of(proc) ((proc)->head.id)
>> #define pid_of(proc) ptid_get_pid ((proc)->head.id)
>> #define lwpid_of(proc) ptid_get_lwp ((proc)->head.id)
>> +#define PIDGET(ptid) ptid_get_pid (ptid)
>> +#define TIDGET(ptid) ptid_get_lwp (ptid)
>>
>> #define get_lwp(inf) ((struct lwp_info *)(inf))
>> #define get_thread_lwp(thr) (get_lwp (inferior_target_data (thr)))
>> Index: linux-x86-64-low.c
>> ===================================================================
>> RCS file: /cvs/src/src/gdb/gdbserver/linux-x86-64-low.c,v
>> retrieving revision 1.22
>> diff -u -p -r1.22 linux-x86-64-low.c
>> --- linux-x86-64-low.c 22 Mar 2009 23:57:10 -0000 1.22
>> +++ linux-x86-64-low.c 30 Apr 2009 01:23:29 -0000
>> @@ -18,9 +18,11 @@
>> You should have received a copy of the GNU General Public License
>> along with this program. If not, see <http://www.gnu.org/licenses/>. */
>>
>> +#include <stddef.h>
>> #include "server.h"
>> #include "linux-low.h"
>> #include "i387-fp.h"
>> +#include "i386-low.h"
>>
>> #include "gdb_proc_service.h"
>>
>> @@ -45,6 +47,11 @@ void init_registers_x86_64_linux (void);
>> #define ARCH_GET_GS 0x1004
>> #endif
>>
>> +struct arch_process_info
>> +{
>> + struct i386_debug_reg_state debug_reg_state;
>> +};
>> +
>> static int x86_64_regmap[] = {
>> RAX * 8, RBX * 8, RCX * 8, RDX * 8,
>> RSI * 8, RDI * 8, RBP * 8, RSP * 8,
>> @@ -161,6 +168,148 @@ x86_64_breakpoint_at (CORE_ADDR pc)
>>
>> return 0;
>> }
>> +
>> +/* Support for debug registers. */
>> +
>> +static unsigned long
>> +x86_64_linux_dr_get (ptid_t ptid, int regnum)
>> +{
>> + int tid;
>> + unsigned long value;
>> +
>> + tid = TIDGET (ptid);
>> + if (tid == 0)
>> + tid = PIDGET (ptid);
>> +
>> + errno = 0;
>> + value = ptrace (PTRACE_PEEKUSER, tid,
>> + offsetof (struct user, u_debugreg[regnum]), 0);
>> + if (errno != 0)
>> + error ("Couldn't read debug register");
>> +
>> + return value;
>> +}
>> +
>> +static void
>> +x86_64_linux_dr_set (ptid_t ptid, int regnum, unsigned long value)
>> +{
>> + int tid;
>> +
>> + tid = TIDGET (ptid);
>> + if (tid == 0)
>> + tid = PIDGET (ptid);
>> +
>> + errno = 0;
>> + ptrace (PTRACE_POKEUSER, tid,
>> + offsetof (struct user, u_debugreg[regnum]), value);
>> + if (errno != 0)
>> + error ("Couldn't write debug register");
>> +}
>> +
>> +/* Pass the address ADDR to the inferior in debug register REGNUM. */
>> +
>> +void
>> +i386_dr_low_set_addr (int regnum, CORE_ADDR addr)
>> +{
>> + struct inferior_list_entry *lp;
>> +
>> + if (! (regnum >= 0 && regnum <= DR_LASTADDR - DR_FIRSTADDR))
>> + error ("Invalid debug register");
>> +
>> + for (lp = all_lwps.head; lp; lp = lp->next)
>> + {
>> + struct lwp_info *lwp = (struct lwp_info *) lp;
>> + x86_64_linux_dr_set (ptid_of (lwp), DR_FIRSTADDR + regnum, addr);
>> + }
>> +}
>> +
>> +/* Pass the value VAL to the inferior in the DR7 debug control register. */
>> +
>> +void
>> +i386_dr_low_set_control (unsigned control)
>> +{
>> + struct inferior_list_entry *lp;
>> +
>> + for (lp = all_lwps.head; lp; lp = lp->next)
>> + {
>> + struct lwp_info *lwp = (struct lwp_info *) lp;
>> + x86_64_linux_dr_set (ptid_of (lwp), DR_CONTROL, control);
>> + }
>> +}
>> +
>> +/* Get the value of the DR6 debug status register from the inferior. */
>> +
>> +unsigned
>> +i386_dr_low_get_status (void)
>> +{
>> + ptid_t inferior_ptid = ptid_of (get_thread_lwp (current_inferior));
>> + return x86_64_linux_dr_get (inferior_ptid, DR_STATUS);
>> +}
>> +
>> +/* Watchpoint support. */
>> +
>> +static int
>> +x86_64_insert_watchpoint (struct arch_process_info *arch_private,
>> + char type, CORE_ADDR addr, int len)
>> +{
>> + return i386_low_insert_watchpoint (&arch_private->debug_reg_state,
>> + type, addr, len);
>> +}
>> +
>> +static int
>> +x86_64_remove_watchpoint (struct arch_process_info *arch_private,
>> + char type, CORE_ADDR addr, int len)
>> +{
>> + return i386_low_remove_watchpoint (&arch_private->debug_reg_state,
>> + type, addr, len);
>> +}
>> +
>> +static int
>> +x86_64_stopped_by_watchpoint (struct arch_process_info *arch_private)
>> +{
>> + return i386_low_stopped_by_watchpoint (&arch_private->debug_reg_state);
>> +}
>> +
>> +static CORE_ADDR
>> +x86_64_stopped_data_address (struct arch_process_info *arch_private)
>> +{
>> + return i386_low_stopped_data_address (&arch_private->debug_reg_state);
>> +}
>> +
>> +/* Called when a new process is created. */
>> +
>> +struct arch_process_info *
>> +x86_64_linux_new_process (int pid, int attached)
>> +{
>> + struct arch_process_info *info = xcalloc (1, sizeof (*info));
>> +
>> + return info;
>> +}
>> +
>> +/* Called when a new thread is detected.
>> + INITIAL is non-zero for the main thread, zero otherwise. */
>> +
>> +static void
>> +x86_64_linux_new_thread (struct lwp_info *lwp, int initial)
>> +{
>> + /* The initial thread has debug regs set later during process
>> + creation/attaching handling. */
>> +
>> + if (! initial)
>> + {
>> + int i;
>> + ptid_t ptid = ptid_of (lwp);
>> + int pid = PIDGET (ptid);
>> + struct process_info *proc = find_process_pid (pid);
>> + struct arch_process_info *arch_private = proc->private->arch_private;
>> + struct i386_debug_reg_state *state = &arch_private->debug_reg_state;
>> +
>> + for (i = DR_FIRSTADDR; i <= DR_LASTADDR; i++)
>> + x86_64_linux_dr_set (ptid, i, state->dr_mirror[i]);
>> +
>> + x86_64_linux_dr_set (ptid, DR_CONTROL, state->dr_control_mirror);
>> + }
>> +}
>>
>> struct linux_target_ops the_low_target = {
>> init_registers_x86_64_linux,
>> @@ -175,10 +324,12 @@ struct linux_target_ops the_low_target =
>> NULL,
>> 1,
>> x86_64_breakpoint_at,
>> + x86_64_insert_watchpoint,
>> + x86_64_remove_watchpoint,
>> + x86_64_stopped_by_watchpoint,
>> + x86_64_stopped_data_address,
>> NULL,
>> NULL,
>> - NULL,
>> - NULL,
>> - NULL,
>> - NULL,
>> + x86_64_linux_new_process,
>> + x86_64_linux_new_thread
>> };
>> Index: server.h
>> ===================================================================
>> RCS file: /cvs/src/src/gdb/gdbserver/server.h,v
>> retrieving revision 1.56
>> diff -u -p -r1.56 server.h
>> --- server.h 3 Apr 2009 20:15:51 -0000 1.56
>> +++ server.h 30 Apr 2009 01:23:29 -0000
>> @@ -405,6 +405,7 @@ void perror_with_name (const char *strin
>> void error (const char *string,...) ATTR_NORETURN ATTR_FORMAT (printf, 1, 2);
>> void fatal (const char *string,...) ATTR_NORETURN ATTR_FORMAT (printf, 1, 2);
>> void warning (const char *string,...) ATTR_FORMAT (printf, 1, 2);
>> +char *paddr (CORE_ADDR addr);
>>
>> /* Maximum number of bytes to read/write at once. The value here
>> is chosen to fill up a packet (the headers account for the 32). */
>> Index: utils.c
>> ===================================================================
>> RCS file: /cvs/src/src/gdb/gdbserver/utils.c,v
>> retrieving revision 1.18
>> diff -u -p -r1.18 utils.c
>> --- utils.c 19 Jan 2009 00:16:46 -0000 1.18
>> +++ utils.c 30 Apr 2009 01:23:29 -0000
>> @@ -170,3 +170,37 @@ warning (const char *string,...)
>> fprintf (stderr, "\n");
>> va_end (args);
>> }
>> +
>> +/* temporary storage using circular buffer */
>> +#define NUMCELLS 4
>> +#define CELLSIZE 50
>> +static char *
>> +get_cell (void)
>> +{
>> + static char buf[NUMCELLS][CELLSIZE];
>> + static int cell = 0;
>> + if (++cell >= NUMCELLS)
>> + cell = 0;
>> + return buf[cell];
>> +}
>> +
>> +static int
>> +xsnprintf (char *str, size_t size, const char *format, ...)
>> +{
>> + va_list args;
>> + int ret;
>> +
>> + va_start (args, format);
>> + ret = vsnprintf (str, size, format, args);
>> + va_end (args);
>> +
>> + return ret;
>> +}
>> +
>> +char *
>> +paddr (CORE_ADDR addr)
>> +{
>> + char *str = get_cell ();
>> + xsnprintf (str, CELLSIZE, "%lx", (long) addr);
>> + return str;
>> +}
>> Index: win32-arm-low.c
>> ===================================================================
>> RCS file: /cvs/src/src/gdb/gdbserver/win32-arm-low.c,v
>> retrieving revision 1.8
>> diff -u -p -r1.8 win32-arm-low.c
>> --- win32-arm-low.c 3 Jan 2009 05:57:57 -0000 1.8
>> +++ win32-arm-low.c 30 Apr 2009 01:23:29 -0000
>> @@ -122,4 +122,9 @@ struct win32_target_ops the_low_target =
>> NULL, /* single_step */
>> (const unsigned char *) &arm_wince_breakpoint,
>> arm_wince_breakpoint_len,
>> + /* Watchpoint related functions. See target.h for comments. */
>> + NULL, /* insert_watchpoint */
>> + NULL, /* remove_watchpoint */
>> + NULL, /* stopped_by_watchpoint */
>> + NULL /* stopped_data_address */
>> };
>> Index: win32-i386-low.c
>> ===================================================================
>> RCS file: /cvs/src/src/gdb/gdbserver/win32-i386-low.c,v
>> retrieving revision 1.14
>> diff -u -p -r1.14 win32-i386-low.c
>> --- win32-i386-low.c 3 Jan 2009 05:57:57 -0000 1.14
>> +++ win32-i386-low.c 30 Apr 2009 01:23:29 -0000
>> @@ -17,6 +17,7 @@
>>
>> #include "server.h"
>> #include "win32-low.h"
>> +#include "i386-low.h"
>>
>> #define FCS_REGNUM 27
>> #define FOP_REGNUM 31
>> @@ -31,6 +32,42 @@ static unsigned dr[8];
>> static int debug_registers_changed = 0;
>> static int debug_registers_used = 0;
>>
>> +/* Pass the address ADDR to the inferior in the I'th debug register.
>> + Here we just store the address in dr array, the registers will be
>> + actually set up when windows_continue is called. */
>> +
>> +void
>> +i386_dr_low_set_addr (int i, CORE_ADDR addr)
>> +{
>> + if (i < 0 || i > 3)
>> + return;
>> + dr[i] = (unsigned) addr;
>> + debug_registers_changed = 1;
>> + debug_registers_used = 1;
>> +}
>> +
>> +/* Pass the value VAL to the inferior in the DR7 debug control register.
>> + Here we just store the address in D_REGS, the watchpoint
>> + will be actually set up in windows_wait. */
>> +
>> +void
>> +i386_dr_low_set_control (unsigned val)
>> +{
>> + dr[7] = val;
>> + debug_registers_changed = 1;
>> + debug_registers_used = 1;
>> +}
>> +
>> +/* Get the value of the DR6 debug status register from the inferior.
>> + Here we just return the value stored in dr[6]
>> + by the last call to thread_rec for current_event.dwThreadId id. */
>> +
>> +unsigned
>> +i386_dr_low_get_status (void)
>> +{
>> + return dr[6];
>> +}
>> +
>> static void
>> i386_initial_stuff (void)
>> {
>> @@ -205,4 +242,8 @@ struct win32_target_ops the_low_target =
>> i386_single_step,
>> NULL, /* breakpoint */
>> 0, /* breakpoint_len */
>> + i386_insert_watchpoint,
>> + i386_remove_watchpoint,
>> + i386_stopped_by_watchpoint,
>> + i386_stopped_data_address
>> };
>> Index: win32-low.c
>> ===================================================================
>> RCS file: /cvs/src/src/gdb/gdbserver/win32-low.c,v
>> retrieving revision 1.35
>> diff -u -p -r1.35 win32-low.c
>> --- win32-low.c 1 Apr 2009 22:50:24 -0000 1.35
>> +++ win32-low.c 30 Apr 2009 01:23:29 -0000
>> @@ -228,6 +228,48 @@ child_delete_thread (DWORD pid, DWORD ti
>> delete_thread_info (thread);
>> }
>>
>> +/* These watchpoint related wrapper functions simply pass on the function call
>> + if the target has registered a corresponding function. */
>> +
>> +static int
>> +win32_insert_watchpoint (char type, CORE_ADDR addr, int len)
>> +{
>> + if (the_low_target.insert_watchpoint != NULL)
>> + return the_low_target.insert_watchpoint (type, addr, len);
>> + else
>> + /* Unsupported (see target.h). */
>> + return 1;
>> +}
>> +
>> +static int
>> +win32_remove_watchpoint (char type, CORE_ADDR addr, int len)
>> +{
>> + if (the_low_target.remove_watchpoint != NULL)
>> + return the_low_target.remove_watchpoint (type, addr, len);
>> + else
>> + /* Unsupported (see target.h). */
>> + return 1;
>> +}
>> +
>> +static int
>> +win32_stopped_by_watchpoint (void)
>> +{
>> + if (the_low_target.stopped_by_watchpoint != NULL)
>> + return the_low_target.stopped_by_watchpoint ();
>> + else
>> + return 0;
>> +}
>> +
>> +static CORE_ADDR
>> +win32_stopped_data_address (void)
>> +{
>> + if (the_low_target.stopped_data_address != NULL)
>> + return the_low_target.stopped_data_address ();
>> + else
>> + return 0;
>> +}
>> +
>> +
>> /* Transfer memory from/to the debugged process. */
>> static int
>> child_xfer_memory (CORE_ADDR memaddr, char *our, int len,
>> @@ -1697,10 +1739,10 @@ static struct target_ops win32_target_op
>> NULL,
>> win32_request_interrupt,
>> NULL,
>> - NULL,
>> - NULL,
>> - NULL,
>> - NULL,
>> + win32_insert_watchpoint,
>> + win32_remove_watchpoint,
>> + win32_stopped_by_watchpoint,
>> + win32_stopped_data_address,
>> NULL,
>> NULL,
>> NULL,
>> Index: win32-low.h
>> ===================================================================
>> RCS file: /cvs/src/src/gdb/gdbserver/win32-low.h,v
>> retrieving revision 1.9
>> diff -u -p -r1.9 win32-low.h
>> --- win32-low.h 3 Jan 2009 05:57:57 -0000 1.9
>> +++ win32-low.h 30 Apr 2009 01:23:29 -0000
>> @@ -70,6 +70,13 @@ struct win32_target_ops
>>
>> const unsigned char *breakpoint;
>> int breakpoint_len;
>> +
>> + /* Watchpoint related functions. See target.h for comments. */
>> + int (*insert_watchpoint) (char type, CORE_ADDR addr, int len);
>> + int (*remove_watchpoint) (char type, CORE_ADDR addr, int len);
>> + int (*stopped_by_watchpoint) (void);
>> + CORE_ADDR (*stopped_data_address) (void);
>> +
>> };
>>
>> extern struct win32_target_ops the_low_target;
>>
>
^ permalink raw reply [flat|nested] 18+ messages in thread
* RE: [RFA] i386/amd64 h/w watchpoints in gdbserver
2009-05-18 23:28 ` Doug Evans
@ 2009-05-19 9:05 ` Pierre Muller
2009-06-02 15:36 ` Doug Evans
0 siblings, 1 reply; 18+ messages in thread
From: Pierre Muller @ 2009-05-19 9:05 UTC (permalink / raw)
To: 'Doug Evans', gdb-patches; +Cc: 'Pedro Alves'
> -----Message d'origine-----
> De : gdb-patches-owner@sourceware.org [mailto:gdb-patches-
> owner@sourceware.org] De la part de Doug Evans
> Envoyé : Tuesday, May 19, 2009 1:28 AM
> À : gdb-patches@sourceware.org; muller@ics.u-strasbg.fr
> Objet : Re: [RFA] i386/amd64 h/w watchpoints in gdbserver
>
> Oh, btw, yes I know it needs updating 'cus i386/amd64 gdbserver is now
> biarch. :-)
> That part is mechanical.
> Is there anything that still needs discussing?
Doug, I think that your should send a new RFA
for an up-to-date patch with the bi-arch stuff.
Do we have an automated testsuite result comparison script
that can be used for gdbserver testing?
I can test compilation on cygwin,
but testing can only be done manually...
Hopefully, Pedro will then be able to review it rapidly.
Pierre Muller
Pascal language support maintainer for GDB
^ permalink raw reply [flat|nested] 18+ messages in thread
* Re: [RFA] i386/amd64 h/w watchpoints in gdbserver
2009-05-19 9:05 ` Pierre Muller
@ 2009-06-02 15:36 ` Doug Evans
2009-06-02 22:47 ` Pierre Muller
2009-06-20 23:54 ` Pedro Alves
0 siblings, 2 replies; 18+ messages in thread
From: Doug Evans @ 2009-06-02 15:36 UTC (permalink / raw)
To: Pierre Muller, Pedro Alves; +Cc: gdb-patches
[-- Attachment #1: Type: text/plain, Size: 1521 bytes --]
On Tue, May 19, 2009 at 2:05 AM, Pierre Muller <muller@ics.u-strasbg.fr> wrote:
> Doug, I think that your should send a new RFA
> for an up-to-date patch with the bi-arch stuff.
> Do we have an automated testsuite result comparison script
> that can be used for gdbserver testing?
I just use --target_board=native-gdbserver.exp and compare before/after.
ref: http://sourceware.org/gdb/wiki/Native_gdbserver_testing
No regressions on amd64 gdbserver, 32-bit and 64-bit.
> I can test compilation on cygwin,
> but testing can only be done manually...
Thanks, can you give this a try?
> Hopefully, Pedro will then be able to review it rapidly.
There's one aspect of this patch that one might want changing.
[I'd like to see the change, fwiw.]
It's ok for higher level routines to refer to global state (within
reason), but it's less ok for lower level routines to refer to global
state (modulo constant tables and such that won't change for the
duration). The higher level routines should pass down context so the
lower level routines don't refer to any global state (again, within
reason).
Applying that principle here means routines in linux-x86-low.c, for
example, should not refer to any global state.
Shall I add parameters to insert_watchpoint, etc. so that, for
example, x86_insert_watchpoint doesn't have to call current_process?
Pedro: Note that this patch does defer updating the debug regs until
just before PTRACE_CONT.
[win32 version already did a similar thing]
[-- Attachment #2: gdb-090601-gdbserver-hw-wp-3.patch.txt --]
[-- Type: text/plain, Size: 53867 bytes --]
2009-06-01 Doug Evans <dje@google.com>
Pierre Muller <muller@ics.u-strasbg.fr>
* Makefile.in (SFILES): Add i386-low.c
(i386_low_h): Define.
(i386-low.o): Add dependencies.
(linux-x86-low.o): Add i386-low.h dependency.
(win32-i386-low.o): Ditto.
* i386-low.c: New file.
* i386-low.h: New file.
* configure.srv (i[34567]86-*-cygwin*): Add i386-low.o to srv_tgtobj.
(i[34567]86-*-linux*, i[34567]86-*-mingw*, x86_64-*-linux*): Ditto.
* linux-low.c (linux_add_process): Initialize arch_private.
(linux_remove_process): Free arch_private.
(add_lwp): Initialize arch_private.
(delete_lwp): Free arch_private.
(linux_resume_one_lwp): Call the_low_target.prepare_to_resume if
provided.
* linux-low.h (process_info_private): New member arch_private.
(lwp_info): New member arch_private.
(linux_target_ops): New members new_process, new_thread,
prepare_to_resume.
(ptid_of, PIDGET, TIDGET): New macros.
* linux-x86-low.c: Include stddef.h, i386-low.h.
(arch_process_info): New struct.
(arch_lwp_info): New struct.
(x86_linux_dr_get, x86_linux_dr_set): New functions.
(i386_dr_low_set_addr, i386_dr_low_set_control): New functions.
(i386_dr_low_get_status): New function.
(x86_insert_watchpoint, x86_remove_watchpoint): New functions.
(x86_stopped_by_watchpoint): New function.
(x86_stopped_data_address): New function.
(x86_linux_new_process, x86_linux_new_thread): New functions.
(x86_linux_prepare_to_resume): New function.
(the_low_target): Add entries for insert_watchpoint, remove_watchpoint,
stopped_by_watchpoint, stopped_data_address, new_process, new_thread,
prepare_to_resume.
* server.h (paddr): Declare.
* utils.c (NUMCELLS, CELLSIZE): New macros.
(get_sell, xsnprintf, paddr): New functions.
* win32-arm-low.c (the_low_target): Add entries for insert_watchpoint,
remove_watchpoint, stopped_by_watchpoint, stopped_data_address.
* win32-i386-low.c: Include i386-low.h.
(debug_reg_state): Replaces dr.
(i386_dr_low_set_addr, i386_dr_low_set_control): New functions.
(i386_dr_low_get_status): New function.
(i386_insert_watchpoint, i386_remove_watchpoint): New functions.
(i386_stopped_by_watchpoint): New function.
(i386_stopped_data_address): New function.
(i386_initial_stuff): Update.
(get_thread_context,set_thread_context,i386_thread_added): Update.
(the_low_target): Add entries for insert_watchpoint,
remove_watchpoint, stopped_by_watchpoint, stopped_data_address.
* win32-low.c (win32_insert_watchpoint): New function.
(win32_remove_watchpoint): New function.
(win32_stopped_by_watchpoint): New function.
(win32_stopped_data_address): New function.
(win32_target_ops): Add entries for insert_watchpoint,
remove_watchpoint, stopped_by_watchpoint, stopped_data_address.
* win32-low.h (win32_target_ops): New members insert_watchpoint,
remove_watchpoint, stopped_by_watchpoint, stopped_data_address.
Index: Makefile.in
===================================================================
RCS file: /cvs/src/src/gdb/gdbserver/Makefile.in,v
retrieving revision 1.74
diff -u -p -r1.74 Makefile.in
--- Makefile.in 12 May 2009 22:25:00 -0000 1.74
+++ Makefile.in 1 Jun 2009 22:02:43 -0000
@@ -104,7 +104,7 @@ SFILES= $(srcdir)/gdbreplay.c $(srcdir)/
$(srcdir)/thread-db.c $(srcdir)/utils.c \
$(srcdir)/linux-arm-low.c $(srcdir)/linux-cris-low.c \
$(srcdir)/linux-crisv32-low.c \
- $(srcdir)/i387-fp.c \
+ ${srcdir}/i386-low.c $(srcdir)/i387-fp.c \
$(srcdir)/linux-ia64-low.c $(srcdir)/linux-low.c \
$(srcdir)/linux-m32r-low.c \
$(srcdir)/linux-m68k-low.c $(srcdir)/linux-mips-low.c \
@@ -287,6 +287,10 @@ signals.o: ../common/signals.c $(server_
memmem.o: ../gnulib/memmem.c
$(CC) -o memmem.o -c $(CPPFLAGS) $(INTERNAL_CFLAGS) $<
+i386_low_h = $(srcdir)/i386-low.h
+
+i386-low.o: i386-low.c $(i386_low_h) $(server_h) $(target_h)
+
i387-fp.o: i387-fp.c $(server_h)
linux-low.o: linux-low.c $(linux_low_h) $(server_h)
@@ -304,7 +308,7 @@ linux-ppc-low.o: linux-ppc-low.c $(linux
linux-s390-low.o: linux-s390-low.c $(linux_low_h) $(server_h)
linux-sh-low.o: linux-sh-low.c $(linux_low_h) $(server_h)
linux-x86-low.o: linux-x86-low.c $(linux_low_h) $(server_h) \
- $(gdb_proc_service_h)
+ $(gdb_proc_service_h) $(i386_low_h)
linux-xtensa-low.o: linux-xtensa-low.c xtensa-xtregs.c $(linux_low_h) $(server_h)
win32_low_h = $(srcdir)/win32-low.h
@@ -312,7 +316,7 @@ win32_low_h = $(srcdir)/win32-low.h
win32-low.o: win32-low.c $(win32_low_h) $(server_h) $(regdef_h) $(regcache_h)
win32-arm-low.o: win32-arm-low.c $(win32_low_h) $(server_h)
-win32-i386-low.o: win32-i386-low.c $(win32_low_h) $(server_h)
+win32-i386-low.o: win32-i386-low.c $(win32_low_h) $(server_h) $(i386_low_h)
spu-low.o: spu-low.c $(server_h)
Index: configure.srv
===================================================================
RCS file: /cvs/src/src/gdb/gdbserver/configure.srv,v
retrieving revision 1.41
diff -u -p -r1.41 configure.srv
--- configure.srv 12 May 2009 22:25:00 -0000 1.41
+++ configure.srv 1 Jun 2009 22:02:43 -0000
@@ -53,10 +53,10 @@ case "${target}" in
srv_linux_thread_db=yes
;;
i[34567]86-*-cygwin*) srv_regobj=reg-i386.o
- srv_tgtobj="win32-low.o win32-i386-low.o"
+ srv_tgtobj="i386-low.o win32-low.o win32-i386-low.o"
;;
i[34567]86-*-linux*) srv_regobj=reg-i386-linux.o
- srv_tgtobj="linux-low.o linux-x86-low.o i387-fp.o"
+ srv_tgtobj="linux-low.o linux-x86-low.o i386-low.o i387-fp.o"
srv_linux_usrregs=yes
srv_linux_regsets=yes
srv_linux_thread_db=yes
@@ -71,7 +71,7 @@ case "${target}" in
srv_mingwce=yes
;;
i[34567]86-*-mingw*) srv_regobj=reg-i386.o
- srv_tgtobj="win32-low.o win32-i386-low.o"
+ srv_tgtobj="i386-low.o win32-low.o win32-i386-low.o"
srv_mingw=yes
;;
ia64-*-linux*) srv_regobj=reg-ia64.o
@@ -170,7 +170,7 @@ case "${target}" in
srv_tgtobj="spu-low.o"
;;
x86_64-*-linux*) srv_regobj="reg-x86-64-linux.o reg-i386-linux.o"
- srv_tgtobj="linux-low.o linux-x86-low.o i387-fp.o"
+ srv_tgtobj="linux-low.o linux-x86-low.o i386-low.o i387-fp.o"
srv_linux_usrregs=yes # This is for i386 progs.
srv_linux_regsets=yes
srv_linux_thread_db=yes
Index: i386-low.c
===================================================================
RCS file: i386-low.c
diff -N i386-low.c
--- /dev/null 1 Jan 1970 00:00:00 -0000
+++ i386-low.c 1 Jun 2009 22:02:43 -0000
@@ -0,0 +1,660 @@
+/* Debug register code for the i386.
+
+ Copyright (C) 2009
+ Free Software Foundation, Inc.
+
+ This file is part of GDB.
+
+ This program is free software; you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation; either version 3 of the License, or
+ (at your option) any later version.
+
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program. If not, see <http://www.gnu.org/licenses/>. */
+
+#include "server.h"
+#include "target.h"
+#include "i386-low.h"
+
+/* Support for 8-byte wide hw watchpoints. */
+#ifndef TARGET_HAS_DR_LEN_8
+#define TARGET_HAS_DR_LEN_8 (sizeof (long) == 8)
+#endif
+
+enum target_hw_bp_type
+ {
+ hw_write = 0, /* Common HW watchpoint */
+ hw_read = 1, /* Read HW watchpoint */
+ hw_access = 2, /* Access HW watchpoint */
+ hw_execute = 3 /* Execute HW breakpoint */
+ };
+
+/* DR7 Debug Control register fields. */
+
+/* How many bits to skip in DR7 to get to R/W and LEN fields. */
+#define DR_CONTROL_SHIFT 16
+/* How many bits in DR7 per R/W and LEN field for each watchpoint. */
+#define DR_CONTROL_SIZE 4
+
+/* Watchpoint/breakpoint read/write fields in DR7. */
+#define DR_RW_EXECUTE (0x0) /* Break on instruction execution. */
+#define DR_RW_WRITE (0x1) /* Break on data writes. */
+#define DR_RW_READ (0x3) /* Break on data reads or writes. */
+
+/* This is here for completeness. No platform supports this
+ functionality yet (as of March 2001). Note that the DE flag in the
+ CR4 register needs to be set to support this. */
+#ifndef DR_RW_IORW
+#define DR_RW_IORW (0x2) /* Break on I/O reads or writes. */
+#endif
+
+/* Watchpoint/breakpoint length fields in DR7. The 2-bit left shift
+ is so we could OR this with the read/write field defined above. */
+#define DR_LEN_1 (0x0 << 2) /* 1-byte region watch or breakpoint. */
+#define DR_LEN_2 (0x1 << 2) /* 2-byte region watch. */
+#define DR_LEN_4 (0x3 << 2) /* 4-byte region watch. */
+#define DR_LEN_8 (0x2 << 2) /* 8-byte region watch (AMD64). */
+
+/* Local and Global Enable flags in DR7.
+
+ When the Local Enable flag is set, the breakpoint/watchpoint is
+ enabled only for the current task; the processor automatically
+ clears this flag on every task switch. When the Global Enable flag
+ is set, the breakpoint/watchpoint is enabled for all tasks; the
+ processor never clears this flag.
+
+ Currently, all watchpoint are locally enabled. If you need to
+ enable them globally, read the comment which pertains to this in
+ i386_insert_aligned_watchpoint below. */
+#define DR_LOCAL_ENABLE_SHIFT 0 /* Extra shift to the local enable bit. */
+#define DR_GLOBAL_ENABLE_SHIFT 1 /* Extra shift to the global enable bit. */
+#define DR_ENABLE_SIZE 2 /* Two enable bits per debug register. */
+
+/* Local and global exact breakpoint enable flags (a.k.a. slowdown
+ flags). These are only required on i386, to allow detection of the
+ exact instruction which caused a watchpoint to break; i486 and
+ later processors do that automatically. We set these flags for
+ backwards compatibility. */
+#define DR_LOCAL_SLOWDOWN (0x100)
+#define DR_GLOBAL_SLOWDOWN (0x200)
+
+/* Fields reserved by Intel. This includes the GD (General Detect
+ Enable) flag, which causes a debug exception to be generated when a
+ MOV instruction accesses one of the debug registers.
+
+ FIXME: My Intel manual says we should use 0xF800, not 0xFC00. */
+#define DR_CONTROL_RESERVED (0xFC00)
+
+/* Auxiliary helper macros. */
+
+/* A value that masks all fields in DR7 that are reserved by Intel. */
+#define I386_DR_CONTROL_MASK (~DR_CONTROL_RESERVED)
+
+/* The I'th debug register is vacant if its Local and Global Enable
+ bits are reset in the Debug Control register. */
+#define I386_DR_VACANT(state, i) \
+ (((state)->dr_control_mirror & (3 << (DR_ENABLE_SIZE * (i)))) == 0)
+
+/* Locally enable the break/watchpoint in the I'th debug register. */
+#define I386_DR_LOCAL_ENABLE(state, i) \
+ do { \
+ (state)->dr_control_mirror |= \
+ (1 << (DR_LOCAL_ENABLE_SHIFT + DR_ENABLE_SIZE * (i))); \
+ } while (0)
+
+/* Globally enable the break/watchpoint in the I'th debug register. */
+#define I386_DR_GLOBAL_ENABLE(state, i) \
+ do { \
+ (state)->dr_control_mirror |= \
+ (1 << (DR_GLOBAL_ENABLE_SHIFT + DR_ENABLE_SIZE * (i))); \
+ } while (0)
+
+/* Disable the break/watchpoint in the I'th debug register. */
+#define I386_DR_DISABLE(state, i) \
+ do { \
+ (state)->dr_control_mirror &= \
+ ~(3 << (DR_ENABLE_SIZE * (i))); \
+ } while (0)
+
+/* Set in DR7 the RW and LEN fields for the I'th debug register. */
+#define I386_DR_SET_RW_LEN(state, i,rwlen) \
+ do { \
+ (state)->dr_control_mirror &= \
+ ~(0x0f << (DR_CONTROL_SHIFT+DR_CONTROL_SIZE*(i))); \
+ (state)->dr_control_mirror |= \
+ ((rwlen) << (DR_CONTROL_SHIFT+DR_CONTROL_SIZE*(i))); \
+ } while (0)
+
+/* Get from DR7 the RW and LEN fields for the I'th debug register. */
+#define I386_DR_GET_RW_LEN(state, i) \
+ (((state)->dr_control_mirror >> (DR_CONTROL_SHIFT + DR_CONTROL_SIZE * (i))) & 0x0f)
+
+/* Did the watchpoint whose address is in the I'th register break? */
+#define I386_DR_WATCH_HIT(state,i) ((state)->dr_status_mirror & (1 << (i)))
+
+/* A macro to loop over all debug registers. */
+#define ALL_DEBUG_REGISTERS(i) for (i = 0; i < DR_NADDR; i++)
+
+/* Whether or not to print the mirrored debug registers. */
+static int maint_show_dr = 0;
+
+/* Types of operations supported by i386_handle_nonaligned_watchpoint. */
+typedef enum { WP_INSERT, WP_REMOVE, WP_COUNT } i386_wp_op_t;
+
+/* Internal functions. */
+
+/* Return the value of a 4-bit field for DR7 suitable for watching a
+ region of LEN bytes for accesses of type TYPE. LEN is assumed to
+ have the value of 1, 2, or 4. */
+static unsigned i386_length_and_rw_bits (int len, enum target_hw_bp_type type);
+
+/* Insert a watchpoint at address ADDR, which is assumed to be aligned
+ according to the length of the region to watch. LEN_RW_BITS is the
+ value of the bit-field from DR7 which describes the length and
+ access type of the region to be watched by this watchpoint. Return
+ 0 on success, -1 on failure. */
+static int i386_insert_aligned_watchpoint (struct i386_debug_reg_state *state,
+ CORE_ADDR addr,
+ unsigned len_rw_bits);
+
+/* Remove a watchpoint at address ADDR, which is assumed to be aligned
+ according to the length of the region to watch. LEN_RW_BITS is the
+ value of the bits from DR7 which describes the length and access
+ type of the region watched by this watchpoint. Return 0 on
+ success, -1 on failure. */
+static int i386_remove_aligned_watchpoint (struct i386_debug_reg_state *state,
+ CORE_ADDR addr,
+ unsigned len_rw_bits);
+
+/* Insert or remove a (possibly non-aligned) watchpoint, or count the
+ number of debug registers required to watch a region at address
+ ADDR whose length is LEN for accesses of type TYPE. Return 0 on
+ successful insertion or removal, a positive number when queried
+ about the number of registers, or -1 on failure. If WHAT is not a
+ valid value, bombs through fatal. */
+static int i386_handle_nonaligned_watchpoint (struct i386_debug_reg_state *state,
+ i386_wp_op_t what,
+ CORE_ADDR addr, int len,
+ enum target_hw_bp_type type);
+\f
+/* Implementation. */
+
+/* Clear the reference counts and forget everything we knew about the
+ debug registers. */
+
+void
+i386_low_cleanup_dregs (struct i386_debug_reg_state *state)
+{
+ int i;
+
+ ALL_DEBUG_REGISTERS(i)
+ {
+ state->dr_mirror[i] = 0;
+ state->dr_ref_count[i] = 0;
+ }
+ state->dr_control_mirror = 0;
+ state->dr_status_mirror = 0;
+}
+
+/* Print the values of the mirrored debug registers. This is called
+ when maint_show_dr is non-zero. To set that up, type "maint
+ show-debug-regs" at GDB's prompt. */
+
+static void
+i386_show_dr (struct i386_debug_reg_state *state,
+ const char *func, CORE_ADDR addr,
+ int len, enum target_hw_bp_type type)
+{
+ int i;
+
+ printf (func);
+ if (addr || len)
+ printf (" (addr=%lx, len=%d, type=%s)",
+ (unsigned long) addr, len,
+ type == hw_write ? "data-write"
+ : (type == hw_read ? "data-read"
+ : (type == hw_access ? "data-read/write"
+ : (type == hw_execute ? "instruction-execute"
+ /* FIXME: if/when I/O read/write
+ watchpoints are supported, add them
+ here. */
+ : "??unknown??"))));
+ printf (":\n");
+ printf ("\tCONTROL (DR7): %08x STATUS (DR6): %08x\n",
+ state->dr_control_mirror, state->dr_status_mirror);
+ ALL_DEBUG_REGISTERS (i)
+ {
+ printf ("\
+\tDR%d: addr=0x%s, ref.count=%d DR%d: addr=0x%s, ref.count=%d\n",
+ i, paddr (state->dr_mirror[i]), state->dr_ref_count[i],
+ i+1, paddr (state->dr_mirror[i+1]), state->dr_ref_count[i+1]);
+ i++;
+ }
+}
+
+/* Return the value of a 4-bit field for DR7 suitable for watching a
+ region of LEN bytes for accesses of type TYPE. LEN is assumed to
+ have the value of 1, 2, or 4. */
+
+static unsigned
+i386_length_and_rw_bits (int len, enum target_hw_bp_type type)
+{
+ unsigned rw;
+
+ switch (type)
+ {
+ case hw_execute:
+ rw = DR_RW_EXECUTE;
+ break;
+ case hw_write:
+ rw = DR_RW_WRITE;
+ break;
+ case hw_read:
+ /* The i386 doesn't support data-read watchpoints. */
+ case hw_access:
+ rw = DR_RW_READ;
+ break;
+#if 0
+ /* Not yet supported. */
+ case hw_io_access:
+ rw = DR_RW_IORW;
+ break;
+#endif
+ default:
+ error ("\
+Invalid hardware breakpoint type %d in i386_length_and_rw_bits.\n",
+ (int) type);
+ }
+
+ switch (len)
+ {
+ case 1:
+ return (DR_LEN_1 | rw);
+ case 2:
+ return (DR_LEN_2 | rw);
+ case 4:
+ return (DR_LEN_4 | rw);
+ case 8:
+ if (TARGET_HAS_DR_LEN_8)
+ return (DR_LEN_8 | rw);
+ default:
+ error ("\
+Invalid hardware breakpoint length %d in i386_length_and_rw_bits.\n", len);
+ }
+}
+
+/* Insert a watchpoint at address ADDR, which is assumed to be aligned
+ according to the length of the region to watch. LEN_RW_BITS is the
+ value of the bits from DR7 which describes the length and access
+ type of the region to be watched by this watchpoint. Return 0 on
+ success, -1 on failure. */
+
+static int
+i386_insert_aligned_watchpoint (struct i386_debug_reg_state *state,
+ CORE_ADDR addr, unsigned len_rw_bits)
+{
+ int i;
+
+ /* First, look for an occupied debug register with the same address
+ and the same RW and LEN definitions. If we find one, we can
+ reuse it for this watchpoint as well (and save a register). */
+ ALL_DEBUG_REGISTERS(i)
+ {
+ if (!I386_DR_VACANT (state, i)
+ && state->dr_mirror[i] == addr
+ && I386_DR_GET_RW_LEN (state, i) == len_rw_bits)
+ {
+ state->dr_ref_count[i]++;
+ return 0;
+ }
+ }
+
+ /* Next, look for a vacant debug register. */
+ ALL_DEBUG_REGISTERS(i)
+ {
+ if (I386_DR_VACANT (state, i))
+ break;
+ }
+
+ /* No more debug registers! */
+ if (i >= DR_NADDR)
+ return -1;
+
+ /* Now set up the register I to watch our region. */
+
+ /* Record the info in our local mirrored array. */
+ state->dr_mirror[i] = addr;
+ state->dr_ref_count[i] = 1;
+ I386_DR_SET_RW_LEN (state, i, len_rw_bits);
+ /* Note: we only enable the watchpoint locally, i.e. in the current
+ task. Currently, no i386 target allows or supports global
+ watchpoints; however, if any target would want that in the
+ future, GDB should probably provide a command to control whether
+ to enable watchpoints globally or locally, and the code below
+ should use global or local enable and slow-down flags as
+ appropriate. */
+ I386_DR_LOCAL_ENABLE (state, i);
+ state->dr_control_mirror |= DR_LOCAL_SLOWDOWN;
+ state->dr_control_mirror &= I386_DR_CONTROL_MASK;
+
+ /* Finally, actually pass the info to the inferior. */
+ i386_dr_low_set_addr (state, i);
+ i386_dr_low_set_control (state);
+
+ return 0;
+}
+
+/* Remove a watchpoint at address ADDR, which is assumed to be aligned
+ according to the length of the region to watch. LEN_RW_BITS is the
+ value of the bits from DR7 which describes the length and access
+ type of the region watched by this watchpoint. Return 0 on
+ success, -1 on failure. */
+
+static int
+i386_remove_aligned_watchpoint (struct i386_debug_reg_state *state,
+ CORE_ADDR addr, unsigned len_rw_bits)
+{
+ int i, retval = -1;
+
+ ALL_DEBUG_REGISTERS(i)
+ {
+ if (!I386_DR_VACANT (state, i)
+ && state->dr_mirror[i] == addr
+ && I386_DR_GET_RW_LEN (state, i) == len_rw_bits)
+ {
+ if (--state->dr_ref_count[i] == 0) /* no longer in use? */
+ {
+ /* Reset our mirror. */
+ state->dr_mirror[i] = 0;
+ I386_DR_DISABLE (state, i);
+ /* Reset it in the inferior. */
+ i386_dr_low_set_control (state);
+ i386_dr_low_set_addr (state, i);
+ }
+ retval = 0;
+ }
+ }
+
+ return retval;
+}
+
+/* Insert or remove a (possibly non-aligned) watchpoint, or count the
+ number of debug registers required to watch a region at address
+ ADDR whose length is LEN for accesses of type TYPE. Return 0 on
+ successful insertion or removal, a positive number when queried
+ about the number of registers, or -1 on failure. If WHAT is not a
+ valid value, bombs through internal_error. */
+
+static int
+i386_handle_nonaligned_watchpoint (struct i386_debug_reg_state *state,
+ i386_wp_op_t what, CORE_ADDR addr, int len,
+ enum target_hw_bp_type type)
+{
+ int retval = 0, status = 0;
+ int max_wp_len = TARGET_HAS_DR_LEN_8 ? 8 : 4;
+
+ static const int size_try_array[8][8] =
+ {
+ {1, 1, 1, 1, 1, 1, 1, 1}, /* Trying size one. */
+ {2, 1, 2, 1, 2, 1, 2, 1}, /* Trying size two. */
+ {2, 1, 2, 1, 2, 1, 2, 1}, /* Trying size three. */
+ {4, 1, 2, 1, 4, 1, 2, 1}, /* Trying size four. */
+ {4, 1, 2, 1, 4, 1, 2, 1}, /* Trying size five. */
+ {4, 1, 2, 1, 4, 1, 2, 1}, /* Trying size six. */
+ {4, 1, 2, 1, 4, 1, 2, 1}, /* Trying size seven. */
+ {8, 1, 2, 1, 4, 1, 2, 1}, /* Trying size eight. */
+ };
+
+ while (len > 0)
+ {
+ int align = addr % max_wp_len;
+ /* Four (eight on AMD64) is the maximum length a debug register
+ can watch. */
+ int try = (len > max_wp_len ? (max_wp_len - 1) : len - 1);
+ int size = size_try_array[try][align];
+
+ if (what == WP_COUNT)
+ {
+ /* size_try_array[] is defined such that each iteration
+ through the loop is guaranteed to produce an address and a
+ size that can be watched with a single debug register.
+ Thus, for counting the registers required to watch a
+ region, we simply need to increment the count on each
+ iteration. */
+ retval++;
+ }
+ else
+ {
+ unsigned len_rw = i386_length_and_rw_bits (size, type);
+
+ if (what == WP_INSERT)
+ status = i386_insert_aligned_watchpoint (state, addr, len_rw);
+ else if (what == WP_REMOVE)
+ status = i386_remove_aligned_watchpoint (state, addr, len_rw);
+ else
+ fatal ("\
+Invalid value %d of operation in i386_handle_nonaligned_watchpoint.\n",
+ (int) what);
+
+ /* We keep the loop going even after a failure, because some
+ of the other aligned watchpoints might still succeed
+ (e.g. if they watch addresses that are already watched,
+ in which case we just increment the reference counts of
+ occupied debug registers). If we break out of the loop
+ too early, we could cause those addresses watched by
+ other watchpoints to be disabled when breakpoint.c reacts
+ to our failure to insert this watchpoint and tries to
+ remove it. */
+ if (status)
+ retval = status;
+ }
+
+ addr += size;
+ len -= size;
+ }
+
+ return retval;
+}
+
+#define Z_PACKET_WRITE_WP '2'
+#define Z_PACKET_READ_WP '3'
+#define Z_PACKET_ACCESS_WP '4'
+
+static int
+Z_packet_to_hw_type (char type)
+{
+ switch (type)
+ {
+ case Z_PACKET_WRITE_WP: return hw_write;
+ case Z_PACKET_READ_WP: return hw_read;
+ case Z_PACKET_ACCESS_WP: return hw_access;
+ default:
+ error ("Z_packet_to_hw_type: bad watchpoint type %c", type);
+ }
+}
+
+/* Insert a watchpoint to watch a memory region which starts at
+ address ADDR and whose length is LEN bytes. Watch memory accesses
+ of the type TYPE_FROM_PACKET. Return 0 on success, -1 on failure. */
+
+int
+i386_low_insert_watchpoint (struct i386_debug_reg_state *state,
+ char type_from_packet, CORE_ADDR addr, int len)
+{
+ int retval;
+ int type = Z_packet_to_hw_type (type_from_packet);
+
+ if (((len != 1 && len !=2 && len !=4) && !(TARGET_HAS_DR_LEN_8 && len == 8))
+ || addr % len != 0)
+ {
+ retval = i386_handle_nonaligned_watchpoint (state, WP_INSERT,
+ addr, len, type);
+ }
+ else
+ {
+ unsigned len_rw = i386_length_and_rw_bits (len, type);
+
+ retval = i386_insert_aligned_watchpoint (state, addr, len_rw);
+ }
+
+ if (maint_show_dr)
+ i386_show_dr (state, "insert_watchpoint", addr, len, type);
+
+ return retval;
+}
+
+/* Remove a watchpoint that watched the memory region which starts at
+ address ADDR, whose length is LEN bytes, and for accesses of the
+ type TYPE_FROM_PACKET. Return 0 on success, -1 on failure. */
+
+int
+i386_low_remove_watchpoint (struct i386_debug_reg_state *state,
+ char type_from_packet, CORE_ADDR addr, int len)
+{
+ int retval;
+ int type = Z_packet_to_hw_type (type_from_packet);
+
+ if (((len != 1 && len !=2 && len !=4) && !(TARGET_HAS_DR_LEN_8 && len == 8))
+ || addr % len != 0)
+ {
+ retval = i386_handle_nonaligned_watchpoint (state, WP_REMOVE,
+ addr, len, type);
+ }
+ else
+ {
+ unsigned len_rw = i386_length_and_rw_bits (len, type);
+
+ retval = i386_remove_aligned_watchpoint (state, addr, len_rw);
+ }
+
+ if (maint_show_dr)
+ i386_show_dr (state, "remove_watchpoint", addr, len, type);
+
+ return retval;
+}
+
+/* Return non-zero if we can watch a memory region that starts at
+ address ADDR and whose length is LEN bytes. */
+
+int
+i386_low_region_ok_for_watchpoint (struct i386_debug_reg_state *state,
+ CORE_ADDR addr, int len)
+{
+ int nregs;
+
+ /* Compute how many aligned watchpoints we would need to cover this
+ region. */
+ nregs = i386_handle_nonaligned_watchpoint (state, WP_COUNT,
+ addr, len, hw_write);
+ return nregs <= DR_NADDR ? 1 : 0;
+}
+
+/* If the inferior has some watchpoint that triggered, set the
+ address associated with that watchpoint and return non-zero.
+ Otherwise, return zero. */
+
+CORE_ADDR
+i386_low_stopped_data_address (struct i386_debug_reg_state *state)
+{
+ CORE_ADDR addr = 0;
+ int i;
+
+ /* Get dr_status_mirror for use by I386_DR_WATCH_HIT. */
+ i386_dr_low_get_status (state);
+
+ ALL_DEBUG_REGISTERS(i)
+ {
+ if (I386_DR_WATCH_HIT (state, i)
+ /* This second condition makes sure DRi is set up for a data
+ watchpoint, not a hardware breakpoint. The reason is
+ that GDB doesn't call the target_stopped_data_address
+ method except for data watchpoints. In other words, I'm
+ being paranoiac. */
+ && I386_DR_GET_RW_LEN (state, i) != 0)
+ {
+ addr = state->dr_mirror[i];
+ if (maint_show_dr)
+ i386_show_dr (state, "watchpoint_hit", addr, -1, hw_write);
+ }
+ }
+
+ if (maint_show_dr && addr == 0)
+ i386_show_dr (state, "stopped_data_addr", 0, 0, hw_write);
+
+ /* NOTE: gdb version checks rc != 0 here. */
+ return addr;
+}
+
+int
+i386_low_stopped_by_watchpoint (struct i386_debug_reg_state *state)
+{
+ CORE_ADDR addr = 0;
+ /* NOTE: gdb version passes boolean found/not-found result from
+ i386_stopped_data_address. */
+ addr = i386_low_stopped_data_address (state);
+ return (addr != 0);
+}
+\f
+/* Support for h/w breakpoints.
+ This support is not currently used, kept for reference. */
+
+/* Return non-zero if the inferior has some break/watchpoint that
+ triggered. */
+
+int
+i386_low_stopped_by_hwbp (struct i386_debug_reg_state *state)
+{
+ int i;
+
+ /* Get dr_status_mirror for use by I386_DR_WATCH_HIT. */
+ i386_dr_low_get_status (state);
+
+ if (maint_show_dr)
+ i386_show_dr (state, "stopped_by_hwbp", 0, 0, hw_execute);
+
+ ALL_DEBUG_REGISTERS(i)
+ {
+ if (I386_DR_WATCH_HIT (state, i))
+ return 1;
+ }
+
+ return 0;
+}
+
+/* Insert a hardware-assisted breakpoint at ADDR.
+ Return 0 on success, -1 on failure. */
+
+int
+i386_low_insert_hw_breakpoint (struct i386_debug_reg_state *state,
+ CORE_ADDR addr)
+{
+ unsigned len_rw = i386_length_and_rw_bits (1, hw_execute);
+ int retval = i386_insert_aligned_watchpoint (state, addr, len_rw);
+
+ if (maint_show_dr)
+ i386_show_dr (state, "insert_hwbp", addr, 1, hw_execute);
+
+ return retval;
+}
+
+/* Remove a hardware-assisted breakpoint at ADDR.
+ Return 0 on success, -1 on failure. */
+
+int
+i386_low_remove_hw_breakpoint (struct i386_debug_reg_state *state,
+ CORE_ADDR addr)
+{
+ unsigned len_rw = i386_length_and_rw_bits (1, hw_execute);
+ int retval = i386_remove_aligned_watchpoint (state, addr, len_rw);
+
+ if (maint_show_dr)
+ i386_show_dr (state, "remove_hwbp", addr, 1, hw_execute);
+
+ return retval;
+}
Index: i386-low.h
===================================================================
RCS file: i386-low.h
diff -N i386-low.h
--- /dev/null 1 Jan 1970 00:00:00 -0000
+++ i386-low.h 1 Jun 2009 22:02:43 -0000
@@ -0,0 +1,120 @@
+/* Misc. low level support for i386.
+
+ Copyright (C) 2009
+ Free Software Foundation, Inc.
+
+ This file is part of GDB.
+
+ This program is free software; you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation; either version 3 of the License, or
+ (at your option) any later version.
+
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program. If not, see <http://www.gnu.org/licenses/>. */
+
+/* Support for hardware watchpoints and breakpoints using the i386
+ debug registers.
+
+ This provides several functions for inserting and removing
+ hardware-assisted breakpoints and watchpoints, testing if one or
+ more of the watchpoints triggered and at what address, checking
+ whether a given region can be watched, etc.
+
+ The functions below implement debug registers sharing by reference
+ counts, and allow to watch regions up to 16 bytes long
+ (32 bytes on 64 bit hosts). */
+
+
+/* Debug registers' indices. */
+#define DR_FIRSTADDR 0
+#define DR_LASTADDR 3
+#define DR_NADDR 4 /* The number of debug address registers. */
+#define DR_STATUS 6
+#define DR_CONTROL 7
+
+/* Global state needed to track h/w watchpoints. */
+
+struct i386_debug_reg_state
+{
+ /* Mirror the inferior's DRi registers. We keep the status and
+ control registers separated because they don't hold addresses. */
+ CORE_ADDR dr_mirror[DR_NADDR];
+ unsigned dr_status_mirror, dr_control_mirror;
+
+ /* Reference counts for each debug register. */
+ int dr_ref_count[DR_NADDR];
+};
+
+/* Clear the reference counts and forget everything we knew about DRi. */
+extern void i386_low_cleanup_dregs (struct i386_debug_reg_state *state);
+
+/* Insert a watchpoint to watch a memory region which starts at
+ address ADDR and whose length is LEN bytes. Watch memory accesses
+ of the type TYPE_FROM_PACKET. Return 0 on success, -1 on failure. */
+extern int i386_low_insert_watchpoint (struct i386_debug_reg_state *state,
+ char type_from_packet, CORE_ADDR addr,
+ int len);
+
+/* Remove a watchpoint that watched the memory region which starts at
+ address ADDR, whose length is LEN bytes, and for accesses of the
+ type TYPE_FROM_PACKET. Return 0 on success, -1 on failure. */
+extern int i386_low_remove_watchpoint (struct i386_debug_reg_state *state,
+ char type_from_packet, CORE_ADDR addr,
+ int len);
+
+/* Return non-zero if we can watch a memory region that starts at
+ address ADDR and whose length is LEN bytes. */
+extern int i386_low_region_ok_for_watchpoint (struct i386_debug_reg_state *state,
+ CORE_ADDR addr, int len);
+
+/* If the inferior has some break/watchpoint that triggered, set
+ the address associated with that break/watchpoint and return
+ true. Otherwise, return false. */
+extern CORE_ADDR i386_low_stopped_data_address (struct i386_debug_reg_state *state);
+
+extern int i386_low_stopped_by_watchpoint (struct i386_debug_reg_state *state);
+
+/* Return non-zero if the inferior has some break/watchpoint that
+ triggered. */
+extern int i386_low_stopped_by_hwbp (struct i386_debug_reg_state *state);
+
+/* Insert a hardware-assisted breakpoint at ADDR.
+ Return 0 on success, -1 on failure. */
+extern int i386_low_insert_hw_breakpoint (struct i386_debug_reg_state *state,
+ CORE_ADDR addr);
+
+/* Remove a hardware-assisted breakpoint at ADDR.
+ Return 0 on success, -1 on failure. */
+extern int i386_low_remove_hw_breakpoint (struct i386_debug_reg_state *state,
+ CORE_ADDR addr);
+\f
+/* Each target needs to provide several low-level functions
+ that will be called to insert watchpoints and hardware breakpoints
+ into the inferior, remove them, and check their status. These
+ functions are:
+
+ i386_dr_low_set_control -- set the debug control (DR7)
+ register to a given value
+
+ i386_dr_low_set_addr -- put an address into one debug register
+
+ i386_dr_low_get_status -- return the value of the debug
+ status (DR6) register.
+*/
+
+/* Update the inferior's debug register REGNUM from STATE. */
+extern void i386_dr_low_set_addr (const struct i386_debug_reg_state *state,
+ int regnum);
+
+/* Update the inferior's DR7 debug control register from STATE. */
+extern void i386_dr_low_set_control (const struct i386_debug_reg_state *state);
+
+/* Get the value of the inferior's DR6 debug status register
+ and record it in STATE. */
+extern void i386_dr_low_get_status (struct i386_debug_reg_state *state);
Index: linux-low.c
===================================================================
RCS file: /cvs/src/src/gdb/gdbserver/linux-low.c,v
retrieving revision 1.105
diff -u -p -r1.105 linux-low.c
--- linux-low.c 24 May 2009 17:44:19 -0000 1.105
+++ linux-low.c 1 Jun 2009 22:02:43 -0000
@@ -224,6 +224,7 @@ delete_lwp (struct lwp_info *lwp)
{
remove_thread (get_lwp_thread (lwp));
remove_inferior (&all_lwps, &lwp->head);
+ free (lwp->arch_private);
free (lwp);
}
@@ -242,6 +243,9 @@ linux_add_process (int pid, int attached
proc = add_process (pid, attached);
proc->private = xcalloc (1, sizeof (*proc->private));
+ if (the_low_target.new_process != NULL)
+ proc->private->arch_private = the_low_target.new_process (pid, attached);
+
return proc;
}
@@ -251,6 +255,7 @@ linux_add_process (int pid, int attached
static void
linux_remove_process (struct process_info *process)
{
+ free (process->private->arch_private);
free (process->private);
remove_process (process);
}
@@ -376,6 +381,9 @@ add_lwp (ptid_t ptid)
lwp->head.id = ptid;
+ if (the_low_target.new_thread != NULL)
+ lwp->arch_private = the_low_target.new_thread (ptid);
+
add_inferior_to_list (&all_lwps, &lwp->head);
return lwp;
@@ -466,7 +474,6 @@ linux_attach_lwp_1 (unsigned long lwpid,
new_lwp = (struct lwp_info *) add_lwp (ptid);
add_thread (ptid, new_lwp);
-
/* We need to wait for SIGSTOP before being able to make the next
ptrace call on this LWP. */
new_lwp->must_set_ptrace_flags = 1;
@@ -1740,6 +1747,9 @@ linux_resume_one_lwp (struct lwp_info *l
*p_sig = NULL;
}
+ if (the_low_target.prepare_to_resume != NULL)
+ the_low_target.prepare_to_resume (lwp);
+
regcache_invalidate_one ((struct inferior_list_entry *)
get_lwp_thread (lwp));
errno = 0;
Index: linux-low.h
===================================================================
RCS file: /cvs/src/src/gdb/gdbserver/linux-low.h,v
retrieving revision 1.30
diff -u -p -r1.30 linux-low.h
--- linux-low.h 12 May 2009 22:25:00 -0000 1.30
+++ linux-low.h 1 Jun 2009 22:02:43 -0000
@@ -56,8 +56,13 @@ struct process_info_private
/* Connection to the libthread_db library. */
td_thragent_t *thread_agent;
+
+ /* Target-specific additions. */
+ struct arch_process_info *arch_private;
};
+struct lwp_info;
+
struct linux_target_ops
{
/* Architecture-specific setup. */
@@ -96,12 +101,28 @@ struct linux_target_ops
If DIRECTION is 1, then copy from INF to NATIVE.
If DIRECTION is 0, copy from NATIVE to INF. */
int (*siginfo_fixup) (struct siginfo *native, void *inf, int direction);
+
+ /* Hook to call when a new process is created or attached to.
+ If the target needs per-process architecture-specific data,
+ allocate it here. */
+ struct arch_process_info * (*new_process) (int pid, int attached);
+
+ /* Hook to call when a new thread is detected.
+ If the target needs per-thread architecture-specific data,
+ allocate it here. */
+ struct arch_lwp_info * (*new_thread) (ptid_t ptid);
+
+ /* Hook to call prior to resuming a thread. */
+ void (*prepare_to_resume) (struct lwp_info *);
};
extern struct linux_target_ops the_low_target;
+#define ptid_of(proc) ((proc)->head.id)
#define pid_of(proc) ptid_get_pid ((proc)->head.id)
#define lwpid_of(proc) ptid_get_lwp ((proc)->head.id)
+#define PIDGET(ptid) ptid_get_pid (ptid)
+#define TIDGET(ptid) ptid_get_lwp (ptid)
#define get_lwp(inf) ((struct lwp_info *)(inf))
#define get_thread_lwp(thr) (get_lwp (inferior_target_data (thr)))
@@ -172,6 +193,9 @@ struct lwp_info
THREAD_KNOWN is set. */
td_thrhandle_t th;
#endif
+
+ /* Target-specific additions. */
+ struct arch_lwp_info *arch_private;
};
extern struct inferior_list all_lwps;
Index: linux-x86-low.c
===================================================================
RCS file: /cvs/src/src/gdb/gdbserver/linux-x86-low.c,v
retrieving revision 1.2
diff -u -p -r1.2 linux-x86-low.c
--- linux-x86-low.c 13 May 2009 19:11:04 -0000 1.2
+++ linux-x86-low.c 1 Jun 2009 22:02:43 -0000
@@ -18,10 +18,12 @@
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>. */
+#include <stddef.h>
#include <signal.h>
#include "server.h"
#include "linux-low.h"
#include "i387-fp.h"
+#include "i386-low.h"
#include "gdb_proc_service.h"
@@ -56,6 +58,21 @@ void init_registers_x86_64_linux (void);
#define ARCH_GET_GS 0x1004
#endif
+/* Per-process arch-specific data we want to keep. */
+
+struct arch_process_info
+{
+ struct i386_debug_reg_state debug_reg_state;
+};
+
+/* Per-thread arch-specific data we want to keep. */
+
+struct arch_lwp_info
+{
+ /* Non-zero if our copy differs from what's recorded in the thread. */
+ int debug_registers_changed;
+};
+
#ifdef __x86_64__
/* Mapping between the general-purpose registers in `struct user'
@@ -317,6 +334,174 @@ x86_breakpoint_at (CORE_ADDR pc)
return 0;
}
\f
+/* Support for debug registers. */
+
+static unsigned long
+x86_linux_dr_get (ptid_t ptid, int regnum)
+{
+ int tid;
+ unsigned long value;
+
+ tid = TIDGET (ptid);
+ if (tid == 0)
+ tid = PIDGET (ptid);
+
+ errno = 0;
+ value = ptrace (PTRACE_PEEKUSER, tid,
+ offsetof (struct user, u_debugreg[regnum]), 0);
+ if (errno != 0)
+ error ("Couldn't read debug register");
+
+ return value;
+}
+
+static void
+x86_linux_dr_set (ptid_t ptid, int regnum, unsigned long value)
+{
+ int tid;
+
+ tid = TIDGET (ptid);
+ if (tid == 0)
+ tid = PIDGET (ptid);
+
+ errno = 0;
+ ptrace (PTRACE_POKEUSER, tid,
+ offsetof (struct user, u_debugreg[regnum]), value);
+ if (errno != 0)
+ error ("Couldn't write debug register");
+}
+
+/* Update the inferior's debug register REGNUM from STATE. */
+
+void
+i386_dr_low_set_addr (const struct i386_debug_reg_state *state, int regnum)
+{
+ struct inferior_list_entry *lp;
+ CORE_ADDR addr;
+
+ if (! (regnum >= 0 && regnum <= DR_LASTADDR - DR_FIRSTADDR))
+ fatal ("Invalid debug register %d", regnum);
+
+ addr = state->dr_mirror[regnum];
+
+ /* ??? Will need tweaking for multi-process. */
+ for (lp = all_lwps.head; lp; lp = lp->next)
+ {
+ struct lwp_info *lwp = (struct lwp_info *) lp;
+
+ /* The actual update is done later, we just mark that the register
+ needs updating. */
+ lwp->arch_private->debug_registers_changed = 1;
+ }
+}
+
+/* Update the inferior's DR7 debug control register from STATE. */
+
+void
+i386_dr_low_set_control (const struct i386_debug_reg_state *state)
+{
+ struct inferior_list_entry *lp;
+
+ /* ??? Will need tweaking for multi-process. */
+ for (lp = all_lwps.head; lp; lp = lp->next)
+ {
+ struct lwp_info *lwp = (struct lwp_info *) lp;
+
+ /* The actual update is done later, we just mark that the register
+ needs updating. */
+ lwp->arch_private->debug_registers_changed = 1;
+ }
+}
+
+/* Get the value of the DR6 debug status register from the inferior
+ and record it in STATE. */
+
+void
+i386_dr_low_get_status (struct i386_debug_reg_state *state)
+{
+ struct lwp_info *lwp = get_thread_lwp (current_inferior);
+ ptid_t ptid = ptid_of (lwp);
+
+ state->dr_status_mirror = x86_linux_dr_get (ptid, DR_STATUS);
+}
+\f
+/* Watchpoint support. */
+
+static int
+x86_insert_watchpoint (char type, CORE_ADDR addr, int len)
+{
+ struct process_info *proc = current_process ();
+ return i386_low_insert_watchpoint (&proc->private->arch_private->debug_reg_state,
+ type, addr, len);
+}
+
+static int
+x86_remove_watchpoint (char type, CORE_ADDR addr, int len)
+{
+ struct process_info *proc = current_process ();
+ return i386_low_remove_watchpoint (&proc->private->arch_private->debug_reg_state,
+ type, addr, len);
+}
+
+static int
+x86_stopped_by_watchpoint (void)
+{
+ struct process_info *proc = current_process ();
+ return i386_low_stopped_by_watchpoint (&proc->private->arch_private->debug_reg_state);
+}
+
+static CORE_ADDR
+x86_stopped_data_address (void)
+{
+ struct process_info *proc = current_process ();
+ return i386_low_stopped_data_address (&proc->private->arch_private->debug_reg_state);
+}
+\f
+/* Called when a new process is created. */
+
+struct arch_process_info *
+x86_linux_new_process (int pid, int attached)
+{
+ struct arch_process_info *info = xcalloc (1, sizeof (*info));
+
+ return info;
+}
+
+/* Called when a new thread is detected. */
+
+static struct arch_lwp_info *
+x86_linux_new_thread (ptid_t ptid)
+{
+ struct arch_lwp_info *info = xcalloc (1, sizeof (*info));
+
+ info->debug_registers_changed = 1;
+
+ return info;
+}
+
+/* Called when resuming a thread.
+ If the debug regs have changed, update the thread's copies. */
+
+static void
+x86_linux_prepare_to_resume (struct lwp_info *lwp)
+{
+ if (lwp->arch_private->debug_registers_changed)
+ {
+ int i;
+ ptid_t ptid = ptid_of (lwp);
+ int pid = ptid_get_pid (ptid);
+ struct process_info *proc = find_process_pid (pid);
+ struct i386_debug_reg_state *state = &proc->private->arch_private->debug_reg_state;
+
+ for (i = DR_FIRSTADDR; i <= DR_LASTADDR; i++)
+ x86_linux_dr_set (ptid, i, state->dr_mirror[i]);
+
+ x86_linux_dr_set (ptid, DR_CONTROL, state->dr_control_mirror);
+
+ lwp->arch_private->debug_registers_changed = 0;
+ }
+}
+\f
/* When GDBSERVER is built as a 64-bit application on linux, the
PTRACE_GETSIGINFO data is always presented in 64-bit layout. Since
debugging a 32-bit inferior with a 64-bit GDBSERVER should look the same
@@ -630,10 +815,10 @@ struct linux_target_ops the_low_target =
NULL,
1,
x86_breakpoint_at,
- NULL,
- NULL,
- NULL,
- NULL,
+ x86_insert_watchpoint,
+ x86_remove_watchpoint,
+ x86_stopped_by_watchpoint,
+ x86_stopped_data_address,
/* collect_ptrace_register/supply_ptrace_register are not needed in the
native i386 case (no registers smaller than an xfer unit), and are not
used in the biarch case (HAVE_LINUX_USRREGS is not defined). */
@@ -641,4 +826,7 @@ struct linux_target_ops the_low_target =
NULL,
/* need to fix up i386 siginfo if host is amd64 */
x86_siginfo_fixup,
+ x86_linux_new_process,
+ x86_linux_new_thread,
+ x86_linux_prepare_to_resume
};
Index: server.h
===================================================================
RCS file: /cvs/src/src/gdb/gdbserver/server.h,v
retrieving revision 1.58
diff -u -p -r1.58 server.h
--- server.h 24 May 2009 21:06:53 -0000 1.58
+++ server.h 1 Jun 2009 22:02:43 -0000
@@ -407,6 +407,7 @@ void perror_with_name (const char *strin
void error (const char *string,...) ATTR_NORETURN ATTR_FORMAT (printf, 1, 2);
void fatal (const char *string,...) ATTR_NORETURN ATTR_FORMAT (printf, 1, 2);
void warning (const char *string,...) ATTR_FORMAT (printf, 1, 2);
+char *paddr (CORE_ADDR addr);
/* Maximum number of bytes to read/write at once. The value here
is chosen to fill up a packet (the headers account for the 32). */
Index: utils.c
===================================================================
RCS file: /cvs/src/src/gdb/gdbserver/utils.c,v
retrieving revision 1.18
diff -u -p -r1.18 utils.c
--- utils.c 19 Jan 2009 00:16:46 -0000 1.18
+++ utils.c 1 Jun 2009 22:02:43 -0000
@@ -170,3 +170,37 @@ warning (const char *string,...)
fprintf (stderr, "\n");
va_end (args);
}
+
+/* temporary storage using circular buffer */
+#define NUMCELLS 4
+#define CELLSIZE 50
+static char *
+get_cell (void)
+{
+ static char buf[NUMCELLS][CELLSIZE];
+ static int cell = 0;
+ if (++cell >= NUMCELLS)
+ cell = 0;
+ return buf[cell];
+}
+
+static int
+xsnprintf (char *str, size_t size, const char *format, ...)
+{
+ va_list args;
+ int ret;
+
+ va_start (args, format);
+ ret = vsnprintf (str, size, format, args);
+ va_end (args);
+
+ return ret;
+}
+
+char *
+paddr (CORE_ADDR addr)
+{
+ char *str = get_cell ();
+ xsnprintf (str, CELLSIZE, "%lx", (long) addr);
+ return str;
+}
Index: win32-arm-low.c
===================================================================
RCS file: /cvs/src/src/gdb/gdbserver/win32-arm-low.c,v
retrieving revision 1.8
diff -u -p -r1.8 win32-arm-low.c
--- win32-arm-low.c 3 Jan 2009 05:57:57 -0000 1.8
+++ win32-arm-low.c 1 Jun 2009 22:02:43 -0000
@@ -122,4 +122,9 @@ struct win32_target_ops the_low_target =
NULL, /* single_step */
(const unsigned char *) &arm_wince_breakpoint,
arm_wince_breakpoint_len,
+ /* Watchpoint related functions. See target.h for comments. */
+ NULL, /* insert_watchpoint */
+ NULL, /* remove_watchpoint */
+ NULL, /* stopped_by_watchpoint */
+ NULL /* stopped_data_address */
};
Index: win32-i386-low.c
===================================================================
RCS file: /cvs/src/src/gdb/gdbserver/win32-i386-low.c,v
retrieving revision 1.14
diff -u -p -r1.14 win32-i386-low.c
--- win32-i386-low.c 3 Jan 2009 05:57:57 -0000 1.14
+++ win32-i386-low.c 1 Jun 2009 22:02:43 -0000
@@ -17,6 +17,7 @@
#include "server.h"
#include "win32-low.h"
+#include "i386-low.h"
#define FCS_REGNUM 27
#define FOP_REGNUM 31
@@ -26,15 +27,80 @@
/* Defined in auto-generated file reg-i386.c. */
void init_registers_i386 (void);
-static unsigned dr[8];
+static struct i386_debug_reg_state debug_reg_state;
static int debug_registers_changed = 0;
static int debug_registers_used = 0;
+/* Update the inferior's debug register REGNUM from STATE. */
+
+void
+i386_dr_low_set_addr (const struct i386_debug_reg_state *state, int regnum)
+{
+ if (! (regnum >= 0 && regnum <= DR_LASTADDR - DR_FIRSTADDR))
+ fatal ("Invalid debug register %d", regnum);
+
+ /* debug_reg_state.dr_mirror is already set.
+ Just notify i386_set_thread_context, i386_thread_added
+ that the registers need to be updated. */
+ debug_registers_changed = 1;
+ debug_registers_used = 1;
+}
+
+/* Update the inferior's DR7 debug control register from STATE. */
+
+void
+i386_dr_low_set_control (const struct i386_debug_reg_state *state)
+{
+ /* debug_reg_state.dr_control_mirror is already set.
+ Just notify i386_set_thread_context, i386_thread_added
+ that the registers need to be updated. */
+ debug_registers_changed = 1;
+ debug_registers_used = 1;
+}
+
+/* Get the value of the DR6 debug status register from the inferior
+ and record it in STATE. */
+
+void
+i386_dr_low_get_status (struct i386_debug_reg_state *state)
+{
+ /* We don't need to do anything here, the last call to thread_rec for
+ current_event.dwThreadId id has already set it. */
+}
+
+/* Watchpoint support. */
+
+static int
+i386_insert_watchpoint (char type, CORE_ADDR addr, int len)
+{
+ return i386_low_insert_watchpoint (&debug_reg_state,
+ type, addr, len);
+}
+
+static int
+i386_remove_watchpoint (char type, CORE_ADDR addr, int len)
+{
+ return i386_low_remove_watchpoint (&debug_reg_state,
+ type, addr, len);
+}
+
+static int
+i386_stopped_by_watchpoint (void)
+{
+ return i386_low_stopped_by_watchpoint (&debug_reg_state);
+}
+
+static CORE_ADDR
+i386_stopped_data_address (void)
+{
+ return i386_low_stopped_data_address (&debug_reg_state);
+}
+
static void
i386_initial_stuff (void)
{
- memset (&dr, 0, sizeof (dr));
+ memset (&debug_reg_state, 0, sizeof (debug_reg_state));
debug_registers_changed = 0;
debug_registers_used = 0;
}
@@ -55,12 +121,13 @@ i386_get_thread_context (win32_thread_in
if (th->tid == current_event->dwThreadId)
{
/* Copy dr values from the current thread. */
- dr[0] = th->context.Dr0;
- dr[1] = th->context.Dr1;
- dr[2] = th->context.Dr2;
- dr[3] = th->context.Dr3;
- dr[6] = th->context.Dr6;
- dr[7] = th->context.Dr7;
+ struct i386_debug_reg_state *dr = &debug_reg_state;
+ dr->dr_mirror[0] = th->context.Dr0;
+ dr->dr_mirror[1] = th->context.Dr1;
+ dr->dr_mirror[2] = th->context.Dr2;
+ dr->dr_mirror[3] = th->context.Dr3;
+ dr->dr_status_mirror = th->context.Dr6;
+ dr->dr_control_mirror = th->context.Dr7;
}
}
@@ -69,13 +136,14 @@ i386_set_thread_context (win32_thread_in
{
if (debug_registers_changed)
{
- th->context.Dr0 = dr[0];
- th->context.Dr1 = dr[1];
- th->context.Dr2 = dr[2];
- th->context.Dr3 = dr[3];
- /* th->context.Dr6 = dr[6];
+ struct i386_debug_reg_state *dr = &debug_reg_state;
+ th->context.Dr0 = dr->dr_mirror[0];
+ th->context.Dr1 = dr->dr_mirror[1];
+ th->context.Dr2 = dr->dr_mirror[2];
+ th->context.Dr3 = dr->dr_mirror[3];
+ /* th->context.Dr6 = dr->dr_status_mirror;
FIXME: should we set dr6 also ?? */
- th->context.Dr7 = dr[7];
+ th->context.Dr7 = dr->dr_control_mirror;
}
SetThreadContext (th->h, &th->context);
@@ -87,16 +155,17 @@ i386_thread_added (win32_thread_info *th
/* Set the debug registers for the new thread if they are used. */
if (debug_registers_used)
{
+ struct i386_debug_reg_state *dr = &debug_reg_state;
th->context.ContextFlags = CONTEXT_DEBUG_REGISTERS;
GetThreadContext (th->h, &th->context);
- th->context.Dr0 = dr[0];
- th->context.Dr1 = dr[1];
- th->context.Dr2 = dr[2];
- th->context.Dr3 = dr[3];
- /* th->context.Dr6 = dr[6];
+ th->context.Dr0 = dr->dr_mirror[0];
+ th->context.Dr1 = dr->dr_mirror[1];
+ th->context.Dr2 = dr->dr_mirror[2];
+ th->context.Dr3 = dr->dr_mirror[3];
+ /* th->context.Dr6 = dr->dr_status_mirror;
FIXME: should we set dr6 also ?? */
- th->context.Dr7 = dr[7];
+ th->context.Dr7 = dr->dr_control_mirror;
SetThreadContext (th->h, &th->context);
th->context.ContextFlags = 0;
@@ -205,4 +274,8 @@ struct win32_target_ops the_low_target =
i386_single_step,
NULL, /* breakpoint */
0, /* breakpoint_len */
+ i386_insert_watchpoint,
+ i386_remove_watchpoint,
+ i386_stopped_by_watchpoint,
+ i386_stopped_data_address
};
Index: win32-low.c
===================================================================
RCS file: /cvs/src/src/gdb/gdbserver/win32-low.c,v
retrieving revision 1.35
diff -u -p -r1.35 win32-low.c
--- win32-low.c 1 Apr 2009 22:50:24 -0000 1.35
+++ win32-low.c 1 Jun 2009 22:02:43 -0000
@@ -228,6 +228,48 @@ child_delete_thread (DWORD pid, DWORD ti
delete_thread_info (thread);
}
+/* These watchpoint related wrapper functions simply pass on the function call
+ if the target has registered a corresponding function. */
+
+static int
+win32_insert_watchpoint (char type, CORE_ADDR addr, int len)
+{
+ if (the_low_target.insert_watchpoint != NULL)
+ return the_low_target.insert_watchpoint (type, addr, len);
+ else
+ /* Unsupported (see target.h). */
+ return 1;
+}
+
+static int
+win32_remove_watchpoint (char type, CORE_ADDR addr, int len)
+{
+ if (the_low_target.remove_watchpoint != NULL)
+ return the_low_target.remove_watchpoint (type, addr, len);
+ else
+ /* Unsupported (see target.h). */
+ return 1;
+}
+
+static int
+win32_stopped_by_watchpoint (void)
+{
+ if (the_low_target.stopped_by_watchpoint != NULL)
+ return the_low_target.stopped_by_watchpoint ();
+ else
+ return 0;
+}
+
+static CORE_ADDR
+win32_stopped_data_address (void)
+{
+ if (the_low_target.stopped_data_address != NULL)
+ return the_low_target.stopped_data_address ();
+ else
+ return 0;
+}
+
+
/* Transfer memory from/to the debugged process. */
static int
child_xfer_memory (CORE_ADDR memaddr, char *our, int len,
@@ -1697,10 +1739,10 @@ static struct target_ops win32_target_op
NULL,
win32_request_interrupt,
NULL,
- NULL,
- NULL,
- NULL,
- NULL,
+ win32_insert_watchpoint,
+ win32_remove_watchpoint,
+ win32_stopped_by_watchpoint,
+ win32_stopped_data_address,
NULL,
NULL,
NULL,
Index: win32-low.h
===================================================================
RCS file: /cvs/src/src/gdb/gdbserver/win32-low.h,v
retrieving revision 1.9
diff -u -p -r1.9 win32-low.h
--- win32-low.h 3 Jan 2009 05:57:57 -0000 1.9
+++ win32-low.h 1 Jun 2009 22:02:43 -0000
@@ -70,6 +70,13 @@ struct win32_target_ops
const unsigned char *breakpoint;
int breakpoint_len;
+
+ /* Watchpoint related functions. See target.h for comments. */
+ int (*insert_watchpoint) (char type, CORE_ADDR addr, int len);
+ int (*remove_watchpoint) (char type, CORE_ADDR addr, int len);
+ int (*stopped_by_watchpoint) (void);
+ CORE_ADDR (*stopped_data_address) (void);
+
};
extern struct win32_target_ops the_low_target;
^ permalink raw reply [flat|nested] 18+ messages in thread
* RE: [RFA] i386/amd64 h/w watchpoints in gdbserver
2009-06-02 15:36 ` Doug Evans
@ 2009-06-02 22:47 ` Pierre Muller
2009-06-03 0:18 ` Doug Evans
2009-06-20 23:54 ` Pedro Alves
1 sibling, 1 reply; 18+ messages in thread
From: Pierre Muller @ 2009-06-02 22:47 UTC (permalink / raw)
To: 'Doug Evans', 'Pedro Alves'; +Cc: gdb-patches
> -----Message d'origine-----
> De : gdb-patches-owner@sourceware.org [mailto:gdb-patches-
> owner@sourceware.org] De la part de Doug Evans
> Envoyé : Tuesday, June 02, 2009 5:36 PM
> À : Pierre Muller; Pedro Alves
> Cc : gdb-patches@sourceware.org
> Objet : Re: [RFA] i386/amd64 h/w watchpoints in gdbserver
>
> On Tue, May 19, 2009 at 2:05 AM, Pierre Muller <muller@ics.u-
> strasbg.fr> wrote:
> > Doug, I think that your should send a new RFA for an up-to-date
> patch
> > with the bi-arch stuff.
> > Do we have an automated testsuite result comparison script that can
> be
> > used for gdbserver testing?
>
> I just use --target_board=native-gdbserver.exp and compare
> before/after.
> ref: http://sourceware.org/gdb/wiki/Native_gdbserver_testing
>
> No regressions on amd64 gdbserver, 32-bit and 64-bit.
Did you try to remove the line saying that
gdbserver does not support hardware watchpoints,
does it change anything?
> > I can test compilation on cygwin,
> > but testing can only be done manually...
>
> Thanks, can you give this a try?
I was able to compile without problems
and test gdb.base/watchpoint.exp
and got 60 PASS (same as gdb itself).
This is the board/hext-gdbserver.exp file I am using
Both noargs and nofileio board infos are commented out,
as gdb.base/args.exp and gdb.base/fileio.exp
give the same results for gdbserver as for normal gdb
(after the commenting out in this configuration file).
<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
# gdbserver running native.
load_generic_config "gdbserver"
process_multilib_options ""
# The default compiler for this target.
set_board_info compiler "[find_gcc]"
# This gdbserver can only run a process once per session.
# set_board_info gdb,do_reload_on_run 1
# There's no support for argument-passing (yet).
# set_board_info noargs 1
# Can't do input (or output) in the current gdbserver.
set_board_info gdb,noinferiorio 1
# gdbserver does not intercept target file operations and perform them
# on the host.
# set_board_info gdb,nofileio 1
# Can't do hardware watchpoints, in general.
# set_board_info gdb,no_hardware_watchpoints 1
set_board_info sockethost "localhost:"
#set_board_info use_gdb_stub 1
#set_board_info gdb_stub libgdbstub
# We will be using the standard GDB remote protocol.
set_board_info gdb_protocol "extended-remote"
# Test the copy of gdbserver in the build directory.
set_board_info gdb_server_prog "../gdbserver/gdbserver"
proc ${board}_spawn { board cmd } {
global board_info
set baseboard [lindex [split $board "/"] 0]
set board_info($baseboard,isremote) 0
set result [remote_spawn $board $cmd]
set board_info($baseboard,isremote) 1
return $result
}
proc ${board}_download { board host dest } {
return $host
}
proc ${board}_file { dest op args } {
if { $op == "delete" } {
return 0
}
return [eval [list standard_file $dest $op] $args]
}
<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
> > Hopefully, Pedro will then be able to review it rapidly.
>
> There's one aspect of this patch that one might want changing.
> [I'd like to see the change, fwiw.]
>
> It's ok for higher level routines to refer to global state (within
> reason), but it's less ok for lower level routines to refer to global
> state (modulo constant tables and such that won't change for the
> duration). The higher level routines should pass down context so the
> lower level routines don't refer to any global state (again, within
> reason).
>
> Applying that principle here means routines in linux-x86-low.c, for
> example, should not refer to any global state.
> Shall I add parameters to insert_watchpoint, etc. so that, for example,
> x86_insert_watchpoint doesn't have to call current_process?
>
> Pedro: Note that this patch does defer updating the debug regs until
> just before PTRACE_CONT.
> [win32 version already did a similar thing]
While I understand your considerations, I would prefer
that this patch gets approved as is. We can always try to improve it
later.
Pierre
^ permalink raw reply [flat|nested] 18+ messages in thread
* Re: [RFA] i386/amd64 h/w watchpoints in gdbserver
2009-06-02 22:47 ` Pierre Muller
@ 2009-06-03 0:18 ` Doug Evans
2009-06-03 16:27 ` Pierre Muller
0 siblings, 1 reply; 18+ messages in thread
From: Doug Evans @ 2009-06-03 0:18 UTC (permalink / raw)
To: Pierre Muller; +Cc: Pedro Alves, gdb-patches
On Tue, Jun 2, 2009 at 3:47 PM, Pierre Muller <muller@ics.u-strasbg.fr> wrote:
>> > Do we have an automated testsuite result comparison script that can
>> be
>> > used for gdbserver testing?
>>
>> I just use --target_board=native-gdbserver.exp and compare
>> before/after.
>> ref: http://sourceware.org/gdb/wiki/Native_gdbserver_testing
>>
>> No regressions on amd64 gdbserver, 32-bit and 64-bit.
>
> Did you try to remove the line saying that
> gdbserver does not support hardware watchpoints,
> does it change anything?
The version I used has:
# Can't do hardware watchpoints, in general.
# But can for i386.
if { [istarget i?86-*-*] || [istarget x86_64-*-* ] } {
;# leave unset, testcases check for whether it is defined
} else {
set_board_info gdb,no_hardware_watchpoints 1
}
Plus while running the testsuite I had this applied:
--- i386-low.c= 2009-06-02 17:11:37.000000000 -0700
+++ i386-low.c 2009-06-02 17:11:52.000000000 -0700
@@ -142,7 +142,7 @@
#define ALL_DEBUG_REGISTERS(i) for (i = 0; i < DR_NADDR; i++)
/* Whether or not to print the mirrored debug registers. */
-static int maint_show_dr = 0;
+static int maint_show_dr = 1;
/* Types of operations supported by i386_handle_nonaligned_watchpoint. */
typedef enum { WP_INSERT, WP_REMOVE, WP_COUNT } i386_wp_op_t;
>
>> > I can test compilation on cygwin,
>> > but testing can only be done manually...
>>
>> Thanks, can you give this a try?
>
> I was able to compile without problems
> and test gdb.base/watchpoint.exp
>
> and got 60 PASS (same as gdb itself).
Thanks for running the tests.
How about watchthreads.exp, watchthreads2.exp?
^ permalink raw reply [flat|nested] 18+ messages in thread
* RE: [RFA] i386/amd64 h/w watchpoints in gdbserver
2009-06-03 0:18 ` Doug Evans
@ 2009-06-03 16:27 ` Pierre Muller
2009-06-09 3:43 ` Doug Evans
0 siblings, 1 reply; 18+ messages in thread
From: Pierre Muller @ 2009-06-03 16:27 UTC (permalink / raw)
To: 'Doug Evans'; +Cc: 'Pedro Alves', gdb-patches
> Thanks for running the tests.
> How about watchthreads.exp, watchthreads2.exp?
I just discovered that file regular expressions work for
the list of tests :)
With patched cygwin gdbserver:
$ make check "RUNTESTFLAGS=-target_board hext-gdbserver gdb.*/wat*.exp"
Nothing to be done for all...
rootme=`pwd`; export rootme; \
srcdir=../../../src/gdb/testsuite ; export srcdir ; \
EXPECT=`if [ -f ${rootme}/../../expect/expect ] ; then echo
${rootme}/..
/../expect/expect ; else echo expect ; fi` ; export EXPECT ; \
EXEEXT=.exe ; export EXEEXT ; \
LD_LIBRARY_PATH=$rootme/../../expect:$rootme/../../libstdc++:$rootme/../
../tk/unix:$rootme/../../tcl/unix:$rootme/../../bfd:$rootme/../../opcodes:$L
D_LI
BRARY_PATH; \
export LD_LIBRARY_PATH; \
if [ -f ${rootme}/../../expect/expect ] ; then \
TCL_LIBRARY=${srcdir}/../../tcl/library ; \
export TCL_LIBRARY ; fi ; \
` if [ -f ${srcdir}/../../dejagnu/runtest ]; then echo
${srcdir}/../../d
ejagnu/runtest; else if [ "i686-pc-cygwin" = "i686-pc-cygwin" ]; then echo
runte
st; else t='s,y,y,'; echo runtest | sed -e $t; fi; fi` -target_board
hext-gdbser
ver gdb.*/wat*.exp
Test Run By Pierre on Wed Jun 3 09:17:15 2009
Native configuration is i686-pc-cygwin
=== gdb tests ===
Schedule of variations:
hext-gdbserver
Running target hext-gdbserver
Using /home/Pierre/.dejagnu/boards/hext-gdbserver.exp as board description
file
for target.
Using ../../../src/gdb/testsuite/config/gdbserver.exp as
tool-and-target-specifi
c interface file.
Running ../../../src/gdb/testsuite/gdb.ada/watch_arg.exp ...
Running ../../../src/gdb/testsuite/gdb.base/watchpoint-hw.exp ...
Running ../../../src/gdb/testsuite/gdb.base/watchpoint-solib.exp ...
Running ../../../src/gdb/testsuite/gdb.base/watchpoint.exp ...
Running ../../../src/gdb/testsuite/gdb.base/watch_thread_num.exp ...
Running ../../../src/gdb/testsuite/gdb.threads/watchthreads.exp ...
FAIL: gdb.threads/watchthreads.exp: threaded watch loop
FAIL: gdb.threads/watchthreads.exp: combination of threaded watchpoints = 30
Running ../../../src/gdb/testsuite/gdb.threads/watchthreads2.exp ...
=== gdb Summary ===
# of expected passes 116
# of unexpected failures 2
# of known failures 1
/usr/local/src/gdbcvs/build/gdb/testsuite/../../gdb/gdb version
6.8.50.20090602
-cvs -nw -nx
make: *** [check] Error 1
I got the same results with cygwin gdb itself...
I am currently investigating the two failures
above and I will come back to this in another email.
Pierre
^ permalink raw reply [flat|nested] 18+ messages in thread
* Re: [RFA] i386/amd64 h/w watchpoints in gdbserver
2009-06-03 16:27 ` Pierre Muller
@ 2009-06-09 3:43 ` Doug Evans
2009-06-10 5:05 ` Pierre Muller
0 siblings, 1 reply; 18+ messages in thread
From: Doug Evans @ 2009-06-09 3:43 UTC (permalink / raw)
To: Pierre Muller; +Cc: Pedro Alves, gdb-patches
On Wed, Jun 3, 2009 at 12:27 PM, Pierre Muller<muller@ics.u-strasbg.fr> wrote:
>> Thanks for running the tests.
>> How about watchthreads.exp, watchthreads2.exp?
>
> [...]
> Running ../../../src/gdb/testsuite/gdb.threads/watchthreads.exp ...
> FAIL: gdb.threads/watchthreads.exp: threaded watch loop
> FAIL: gdb.threads/watchthreads.exp: combination of threaded watchpoints = 30
> Running ../../../src/gdb/testsuite/gdb.threads/watchthreads2.exp ...
>
> === gdb Summary ===
>
> # of expected passes 116
> # of unexpected failures 2
> # of known failures 1
> /usr/local/src/gdbcvs/build/gdb/testsuite/../../gdb/gdb version
> 6.8.50.20090602
> -cvs -nw -nx
>
> make: *** [check] Error 1
>
> I got the same results with cygwin gdb itself...
>
> I am currently investigating the two failures
> above and I will come back to this in another email.
Hi. For clarification, are these failures regressions, or do the
tests still fail without the patch?
^ permalink raw reply [flat|nested] 18+ messages in thread
* RE: [RFA] i386/amd64 h/w watchpoints in gdbserver
2009-06-09 3:43 ` Doug Evans
@ 2009-06-10 5:05 ` Pierre Muller
2009-06-18 19:04 ` Doug Evans
0 siblings, 1 reply; 18+ messages in thread
From: Pierre Muller @ 2009-06-10 5:05 UTC (permalink / raw)
To: 'Doug Evans'; +Cc: 'Pedro Alves', gdb-patches
> -----Message d'origine-----
> De : gdb-patches-owner@sourceware.org [mailto:gdb-patches-
> owner@sourceware.org] De la part de Doug Evans
> Envoyé : Tuesday, June 09, 2009 5:43 AM
> À : Pierre Muller
> Cc : Pedro Alves; gdb-patches@sourceware.org
> Objet : Re: [RFA] i386/amd64 h/w watchpoints in gdbserver
>
> On Wed, Jun 3, 2009 at 12:27 PM, Pierre Muller<muller@ics.u-strasbg.fr>
> wrote:
> >> Thanks for running the tests.
> >> How about watchthreads.exp, watchthreads2.exp?
> >
> > [...]
> > Running ../../../src/gdb/testsuite/gdb.threads/watchthreads.exp ...
> > FAIL: gdb.threads/watchthreads.exp: threaded watch loop
> > FAIL: gdb.threads/watchthreads.exp: combination of threaded
> watchpoints = 30
> > Running ../../../src/gdb/testsuite/gdb.threads/watchthreads2.exp ...
> >
> > === gdb Summary ===
> >
> > # of expected passes 116
> > # of unexpected failures 2
> > # of known failures 1
> > /usr/local/src/gdbcvs/build/gdb/testsuite/../../gdb/gdb version
> > 6.8.50.20090602
> > -cvs -nw -nx
> >
> > make: *** [check] Error 1
> >
> > I got the same results with cygwin gdb itself...
> >
> > I am currently investigating the two failures
> > above and I will come back to this in another email.
>
> Hi. For clarification, are these failures regressions, or do the
> tests still fail without the patch?
Not really, as these two tests are only run
if the target supports hardware watchpoints.
This means that current gdbserver from CVS HEAD
would skip that test.
Anyhow, I think that there are problems with the gdb.threads/watchthreads2.c
code with cygwin.
When run directly, this code should write a bunch of thread switches and
exit,
but I seems to freeze...
Pierre
^ permalink raw reply [flat|nested] 18+ messages in thread
* Re: [RFA] i386/amd64 h/w watchpoints in gdbserver
2009-06-10 5:05 ` Pierre Muller
@ 2009-06-18 19:04 ` Doug Evans
0 siblings, 0 replies; 18+ messages in thread
From: Doug Evans @ 2009-06-18 19:04 UTC (permalink / raw)
To: Pierre Muller, Pedro Alves; +Cc: gdb-patches
On Tue, Jun 9, 2009 at 10:04 PM, Pierre Muller<muller@ics.u-strasbg.fr> wrote:
>> > make: *** [check] Error 1
>> >
>> > I got the same results with cygwin gdb itself...
>> >
>> > I am currently investigating the two failures
>> > above and I will come back to this in another email.
>>
>> Hi. For clarification, are these failures regressions, or do the
>> tests still fail without the patch?
>
> Not really, as these two tests are only run
> if the target supports hardware watchpoints.
> This means that current gdbserver from CVS HEAD
> would skip that test.
>
> Anyhow, I think that there are problems with the gdb.threads/watchthreads2.c
> code with cygwin.
> When run directly, this code should write a bunch of thread switches and
> exit,
> but I seems to freeze...
Ping.
^ permalink raw reply [flat|nested] 18+ messages in thread
* Re: [RFA] i386/amd64 h/w watchpoints in gdbserver
2009-06-02 15:36 ` Doug Evans
2009-06-02 22:47 ` Pierre Muller
@ 2009-06-20 23:54 ` Pedro Alves
2009-06-23 7:37 ` Doug Evans
1 sibling, 1 reply; 18+ messages in thread
From: Pedro Alves @ 2009-06-20 23:54 UTC (permalink / raw)
To: Doug Evans; +Cc: Pierre Muller, gdb-patches
On Tuesday 02 June 2009 16:36:05, Doug Evans wrote:
> RCS file: i386-low.c
> diff -N i386-low.c
> --- /dev/null 1 Jan 1970 00:00:00 -0000
> +++ i386-low.c 1 Jun 2009 22:02:43 -0000
> @@ -0,0 +1,660 @@
> +/* Support for 8-byte wide hw watchpoints. */
> +#ifndef TARGET_HAS_DR_LEN_8
> +#define TARGET_HAS_DR_LEN_8 (sizeof (long) == 8)
Note: this will be trouble for Win64 (sizeof(long) == 4, sizeof (ptr) == 8)
> +/* Set in DR7 the RW and LEN fields for the I'th debug register. */
> +#define I386_DR_SET_RW_LEN(state, i,rwlen) \
> + do { \
> + (state)->dr_control_mirror &= \
> + ~(0x0f << (DR_CONTROL_SHIFT+DR_CONTROL_SIZE*(i))); \
> + (state)->dr_control_mirror |= \
> + ((rwlen) << (DR_CONTROL_SHIFT+DR_CONTROL_SIZE*(i))); \
> + } while (0)
Spaces around operators missing, here and several other places.
I realise this is copied from GDB, but IWBN to fix this while we
go. Feel free to fix it on GDB as well, as obvious.
> +/* Whether or not to print the mirrored debug registers. */
> +static int maint_show_dr = 0;
I see nowhere where this can be set. There are a few references to
GDB's main show-debug-regs command left behind. Could this be set with
a command line option and/or monitor command perhaps?
> +
> +/* Types of operations supported by i386_handle_nonaligned_watchpoint. */
> +typedef enum { WP_INSERT, WP_REMOVE, WP_COUNT } i386_wp_op_t;
> +
> +/* Internal functions. */
> +
> +/* Return the value of a 4-bit field for DR7 suitable for watching a
> + region of LEN bytes for accesses of type TYPE. LEN is assumed to
> + have the value of 1, 2, or 4. */
> +static unsigned i386_length_and_rw_bits (int len, enum target_hw_bp_type type);
> +
> +/* Insert a watchpoint at address ADDR, which is assumed to be aligned
> + according to the length of the region to watch. LEN_RW_BITS is the
> + value of the bit-field from DR7 which describes the length and
> + access type of the region to be watched by this watchpoint. Return
> + 0 on success, -1 on failure. */
> +static int i386_insert_aligned_watchpoint (struct i386_debug_reg_state *state,
> + CORE_ADDR addr,
> + unsigned len_rw_bits);
> +
> +/* Remove a watchpoint at address ADDR, which is assumed to be aligned
> + according to the length of the region to watch. LEN_RW_BITS is the
> + value of the bits from DR7 which describes the length and access
> + type of the region watched by this watchpoint. Return 0 on
> + success, -1 on failure. */
> +static int i386_remove_aligned_watchpoint (struct i386_debug_reg_state *state,
> + CORE_ADDR addr,
> + unsigned len_rw_bits);
> +
> +/* Insert or remove a (possibly non-aligned) watchpoint, or count the
> + number of debug registers required to watch a region at address
> + ADDR whose length is LEN for accesses of type TYPE. Return 0 on
> + successful insertion or removal, a positive number when queried
> + about the number of registers, or -1 on failure. If WHAT is not a
> + valid value, bombs through fatal. */
> +static int i386_handle_nonaligned_watchpoint (struct i386_debug_reg_state *state,
> + i386_wp_op_t what,
> + CORE_ADDR addr, int len,
> + enum target_hw_bp_type type);
I don't think none of these forward declarations is needed?
> +\f
> +/* Implementation. */
> +
> +/* Clear the reference counts and forget everything we knew about the
> + debug registers. */
> +
> +void
> +i386_low_cleanup_dregs (struct i386_debug_reg_state *state)
> +{
> + int i;
> +
> + ALL_DEBUG_REGISTERS(i)
> + {
> + state->dr_mirror[i] = 0;
> + state->dr_ref_count[i] = 0;
> + }
> + state->dr_control_mirror = 0;
> + state->dr_status_mirror = 0;
> +}
This isn't called anywhere?
> +
> +/* Print the values of the mirrored debug registers. This is called
> + when maint_show_dr is non-zero.
> To set that up, type "maint
> + show-debug-regs" at GDB's prompt. */
Nope, this is a lie.
> +
> +static void
> +i386_show_dr (struct i386_debug_reg_state *state,
> + const char *func, CORE_ADDR addr,
> + int len, enum target_hw_bp_type type)
> +{
> + int i;
> +
> + printf (func);
> + if (addr || len)
> + printf (" (addr=%lx, len=%d, type=%s)",
> + (unsigned long) addr, len,
> + type == hw_write ? "data-write"
> + : (type == hw_read ? "data-read"
> + : (type == hw_access ? "data-read/write"
> + : (type == hw_execute ? "instruction-execute"
> + /* FIXME: if/when I/O read/write
> + watchpoints are supported, add them
> + here. */
> + : "??unknown??"))));
> + printf (":\n");
> + printf ("\tCONTROL (DR7): %08x STATUS (DR6): %08x\n",
> + state->dr_control_mirror, state->dr_status_mirror);
> + ALL_DEBUG_REGISTERS (i)
> + {
> + printf ("\
> +\tDR%d: addr=0x%s, ref.count=%d DR%d: addr=0x%s, ref.count=%d\n",
> + i, paddr (state->dr_mirror[i]), state->dr_ref_count[i],
> + i+1, paddr (state->dr_mirror[i+1]), state->dr_ref_count[i+1]);
> + i++;
> + }
> +}
These should not go to stdout. GDB should be fixed too to make these go to
gdb_stdlog.
> +
> +static int
> +Z_packet_to_hw_type (char type)
> +{
> + switch (type)
> + {
> + case Z_PACKET_WRITE_WP: return hw_write;
> + case Z_PACKET_READ_WP: return hw_read;
> + case Z_PACKET_ACCESS_WP: return hw_access;
Please don't vertically align. Stick to the standards and put
those return statements in their own line.
> + default:
> + error ("Z_packet_to_hw_type: bad watchpoint type %c", type);
> + }
> +}
> +
> +/* Insert a watchpoint to watch a memory region which starts at
> + address ADDR and whose length is LEN bytes. Watch memory accesses
> + of the type TYPE_FROM_PACKET. Return 0 on success, -1 on failure. */
> +
> +int
> +i386_low_insert_watchpoint (struct i386_debug_reg_state *state,
> + char type_from_packet, CORE_ADDR addr, int len)
> +{
> + int retval;
> + int type = Z_packet_to_hw_type (type_from_packet);
> +
> + if (((len != 1 && len !=2 && len !=4) && !(TARGET_HAS_DR_LEN_8 && len == 8))
More examples of missing space around operators coming from GDB.
> +
> +/* If the inferior has some watchpoint that triggered, set the
> + address associated with that watchpoint and return non-zero.
> + Otherwise, return zero. */
> +
> +CORE_ADDR
> +i386_low_stopped_data_address (struct i386_debug_reg_state *state)
> +{
> + CORE_ADDR addr = 0;
> + int i;
> +
> + /* Get dr_status_mirror for use by I386_DR_WATCH_HIT. */
> + i386_dr_low_get_status (state);
> +
> + ALL_DEBUG_REGISTERS(i)
> + {
> + if (I386_DR_WATCH_HIT (state, i)
> + /* This second condition makes sure DRi is set up for a data
> + watchpoint, not a hardware breakpoint. The reason is
> + that GDB doesn't call the target_stopped_data_address
> + method except for data watchpoints. In other words, I'm
> + being paranoiac. */
> + && I386_DR_GET_RW_LEN (state, i) != 0)
> + {
> + addr = state->dr_mirror[i];
> + if (maint_show_dr)
> + i386_show_dr (state, "watchpoint_hit", addr, -1, hw_write);
> + }
> + }
> +
> + if (maint_show_dr && addr == 0)
> + i386_show_dr (state, "stopped_data_addr", 0, 0, hw_write);
> +
> + /* NOTE: gdb version checks rc != 0 here. */
> + return addr;
> +}
Indeed. GDB's interface was fixed to allow watchpoints at 0. I
don't think that matters for any gdbserver target, but it would
be nice to fix the interface anyway...
> +
> +int
> +i386_low_stopped_by_watchpoint (struct i386_debug_reg_state *state)
> +{
> + CORE_ADDR addr = 0;
> + /* NOTE: gdb version passes boolean found/not-found result from
> + i386_stopped_data_address. */
> + addr = i386_low_stopped_data_address (state);
> + return (addr != 0);
> +}
Same as above. You've probably thought about that too...
> +\f
> +/* Support for h/w breakpoints.
> + This support is not currently used, kept for reference. */
Any reason for not using this currently? If there's a good reason,
than let's drop it. But I'd prefer to have it working. :-)
> Index: utils.c
> ===================================================================
+char *
+paddr (CORE_ADDR addr)
This isn't documented in neither server.h or here?
+{
+ char *str = get_cell ();
+ xsnprintf (str, CELLSIZE, "%lx", (long) addr);
^^^^
Note: this will be wrong on Win64... BTW, Ulrich
was removing several of these functions from GDB
in the removing-current_gdbarch series. Will this one
stay? Might be worth it to use the one that is going
to stay in GDB.
+ return str;
+}
> Index: linux-low.c
> ===================================================================
> RCS file: /cvs/src/src/gdb/gdbserver/linux-low.c,v
> retrieving revision 1.105
> diff -u -p -r1.105 linux-low.c
> --- linux-low.c 24 May 2009 17:44:19 -0000 1.105
> +++ linux-low.c 1 Jun 2009 22:02:43 -0000
> @@ -224,6 +224,7 @@ delete_lwp (struct lwp_info *lwp)
> {
> remove_thread (get_lwp_thread (lwp));
> remove_inferior (&all_lwps, &lwp->head);
> + free (lwp->arch_private);
> free (lwp);
> }
>
> @@ -242,6 +243,9 @@ linux_add_process (int pid, int attached
> proc = add_process (pid, attached);
> proc->private = xcalloc (1, sizeof (*proc->private));
>
> + if (the_low_target.new_process != NULL)
> + proc->private->arch_private = the_low_target.new_process (pid, attached);
( Wouldn't the interface be a bit cleaner if you
passed the 'proc' pointer down to new_process, and have the
callback manage arch_private field itself? As is, your passing
some useless parameters down. If they end up being needed,
it is likely that an extra look up on pid would be needed to
get at the structure. This would also migrate better to a
per-process data mechanism similar to gdb's objfile_data, if
need be. )
> Index: linux-low.h
> ===================================================================
> RCS file: /cvs/src/src/gdb/gdbserver/linux-low.h,v
> retrieving revision 1.30
> diff -u -p -r1.30 linux-low.h
> --- linux-low.h 12 May 2009 22:25:00 -0000 1.30
> +++ linux-low.h 1 Jun 2009 22:02:43 -0000
> @@ -56,8 +56,13 @@ struct process_info_private
>
> /* Connection to the libthread_db library. */
> td_thragent_t *thread_agent;
> +
> + /* Target-specific additions. */
Warning: "Target" overload. We need to get into the habit
of not doing this --- it makes refering to these things quite
ambiguous. Call it "arch" or something else. There are other
similar cases.
> #define pid_of(proc) ptid_get_pid ((proc)->head.id)
> #define lwpid_of(proc) ptid_get_lwp ((proc)->head.id)
> +#define PIDGET(ptid) ptid_get_pid (ptid)
> +#define TIDGET(ptid) ptid_get_lwp (ptid)
Why do we need extra ways to do the same thing? Let's not
copy GDB's bad habits and legacy code.
> --- linux-x86-low.c 13 May 2009 19:11:04 -0000 1.2
> +++ linux-x86-low.c 1 Jun 2009 22:02:43 -0000
> +static unsigned long
> +x86_linux_dr_get (ptid_t ptid, int regnum)
> +{
> + int tid;
> + unsigned long value;
> +
> + tid = TIDGET (ptid);
> + if (tid == 0)
> + tid = PIDGET (ptid);
The tid == 0 case is dead code coming from GDB, isn't it?
Likewise in other places.
> +
> + errno = 0;
> + value = ptrace (PTRACE_PEEKUSER, tid,
> + offsetof (struct user, u_debugreg[regnum]), 0);
> + if (errno != 0)
> + error ("Couldn't read debug register");
> +
> + return value;
> +}
> +
> +/* Update the inferior's debug register REGNUM from STATE. */
> +
> +void
> +i386_dr_low_set_addr (const struct i386_debug_reg_state *state, int regnum)
> +{
> + struct inferior_list_entry *lp;
> + CORE_ADDR addr;
> +
> + if (! (regnum >= 0 && regnum <= DR_LASTADDR - DR_FIRSTADDR))
> + fatal ("Invalid debug register %d", regnum);
> +
> + addr = state->dr_mirror[regnum];
> +
> + /* ??? Will need tweaking for multi-process. */
Indeed. Why not just set the debug_registers_changed in lwps
of the current process?
> + for (lp = all_lwps.head; lp; lp = lp->next)
> + {
> + struct lwp_info *lwp = (struct lwp_info *) lp;
> +
> + /* The actual update is done later, we just mark that the register
> + needs updating. */
> + lwp->arch_private->debug_registers_changed = 1;
> + }
Thanks, this is likely more non-stop friendly than the win32 version.
We can just send a SIGSTOP to each thread that is stopped, and set
stop_expected. Then, the debug register updating just works. (we'll
still need to make sure that moribund locations work with watchpoints
though)
> Index: utils.c
> ===================================================================
> RCS file: /cvs/src/src/gdb/gdbserver/utils.c,v
> retrieving revision 1.18
> diff -u -p -r1.18 utils.c
> --- utils.c 19 Jan 2009 00:16:46 -0000 1.18
> +++ utils.c 1 Jun 2009 22:02:43 -0000
> @@ -170,3 +170,37 @@ warning (const char *string,...)
> fprintf (stderr, "\n");
> va_end (args);
> }
> +
> +/* temporary storage using circular buffer */
More bogus formatting copied from GDB. Full sentence: capitalize, period,
double space.
> +#define NUMCELLS 4
> +#define CELLSIZE 50
> +static char *
> +get_cell (void)
> +{
> + static char buf[NUMCELLS][CELLSIZE];
> + static int cell = 0;
> + if (++cell >= NUMCELLS)
> + cell = 0;
> + return buf[cell];
> +}
> +
Otherwise, this is looking good to me. I still feel that
exposing the debug registers to GDB (as per-process wide
registers), as opposed to using Z packets would be an
alternative worth investigating, that would avoid having
to mostly copy i386-nat.c to gdbserver/i386-low.c. But,
the Z packets interface already exists, so, that can
always be investigated at any later time...
--
Pedro Alves
^ permalink raw reply [flat|nested] 18+ messages in thread
* Re: [RFA] i386/amd64 h/w watchpoints in gdbserver
2009-06-20 23:54 ` Pedro Alves
@ 2009-06-23 7:37 ` Doug Evans
2009-06-29 20:45 ` Pedro Alves
0 siblings, 1 reply; 18+ messages in thread
From: Doug Evans @ 2009-06-23 7:37 UTC (permalink / raw)
To: Pedro Alves; +Cc: Pierre Muller, gdb-patches
[-- Attachment #1: Type: text/plain, Size: 16563 bytes --]
On Sat, Jun 20, 2009 at 4:55 PM, Pedro Alves<pedro@codesourcery.com> wrote:
> On Tuesday 02 June 2009 16:36:05, Doug Evans wrote:
>
>> RCS file: i386-low.c
>> diff -N i386-low.c
>> --- /dev/null 1 Jan 1970 00:00:00 -0000
>> +++ i386-low.c 1 Jun 2009 22:02:43 -0000
>> @@ -0,0 +1,660 @@
>
>
>> +/* Support for 8-byte wide hw watchpoints. */
>> +#ifndef TARGET_HAS_DR_LEN_8
>> +#define TARGET_HAS_DR_LEN_8 (sizeof (long) == 8)
>
> Note: this will be trouble for Win64 (sizeof(long) == 4, sizeof (ptr) == 8)
changed to sizeof (void *)
>> +/* Set in DR7 the RW and LEN fields for the I'th debug register. */
>> +#define I386_DR_SET_RW_LEN(state, i,rwlen) \
>> + do { \
>> + (state)->dr_control_mirror &= \
>> + ~(0x0f << (DR_CONTROL_SHIFT+DR_CONTROL_SIZE*(i))); \
>> + (state)->dr_control_mirror |= \
>> + ((rwlen) << (DR_CONTROL_SHIFT+DR_CONTROL_SIZE*(i))); \
>> + } while (0)
>
> Spaces around operators missing, here and several other places.
> I realise this is copied from GDB, but IWBN to fix this while we
> go. Feel free to fix it on GDB as well, as obvious.
patch updated.
>> +/* Whether or not to print the mirrored debug registers. */
>> +static int maint_show_dr = 0;
>
> I see nowhere where this can be set. There are a few references to
> GDB's main show-debug-regs command left behind. Could this be set with
> a command line option and/or monitor command perhaps?
It was useful during debugging, I just hardcoded it to 1.
As for how to really enable set it, I wasn't sure.
I added a monitor command.
>
>> +
>> +/* Types of operations supported by i386_handle_nonaligned_watchpoint. */
>> +typedef enum { WP_INSERT, WP_REMOVE, WP_COUNT } i386_wp_op_t;
>> +
>> +/* Internal functions. */
>> +
>> +/* Return the value of a 4-bit field for DR7 suitable for watching a
>> + region of LEN bytes for accesses of type TYPE. LEN is assumed to
>> + have the value of 1, 2, or 4. */
>> +static unsigned i386_length_and_rw_bits (int len, enum target_hw_bp_type type);
>> +
>> +/* Insert a watchpoint at address ADDR, which is assumed to be aligned
>> + according to the length of the region to watch. LEN_RW_BITS is the
>> + value of the bit-field from DR7 which describes the length and
>> + access type of the region to be watched by this watchpoint. Return
>> + 0 on success, -1 on failure. */
>> +static int i386_insert_aligned_watchpoint (struct i386_debug_reg_state *state,
>> + CORE_ADDR addr,
>> + unsigned len_rw_bits);
>> +
>> +/* Remove a watchpoint at address ADDR, which is assumed to be aligned
>> + according to the length of the region to watch. LEN_RW_BITS is the
>> + value of the bits from DR7 which describes the length and access
>> + type of the region watched by this watchpoint. Return 0 on
>> + success, -1 on failure. */
>> +static int i386_remove_aligned_watchpoint (struct i386_debug_reg_state *state,
>> + CORE_ADDR addr,
>> + unsigned len_rw_bits);
>> +
>> +/* Insert or remove a (possibly non-aligned) watchpoint, or count the
>> + number of debug registers required to watch a region at address
>> + ADDR whose length is LEN for accesses of type TYPE. Return 0 on
>> + successful insertion or removal, a positive number when queried
>> + about the number of registers, or -1 on failure. If WHAT is not a
>> + valid value, bombs through fatal. */
>> +static int i386_handle_nonaligned_watchpoint (struct i386_debug_reg_state *state,
>> + i386_wp_op_t what,
>> + CORE_ADDR addr, int len,
>> + enum target_hw_bp_type type);
>
> I don't think none of these forward declarations is needed?
ok
[once upon a time, they were ok. the new rules haven't been locked in
memory yet]
>> +
>> +/* Implementation. */
>> +
>> +/* Clear the reference counts and forget everything we knew about the
>> + debug registers. */
>> +
>> +void
>> +i386_low_cleanup_dregs (struct i386_debug_reg_state *state)
>> +{
>> + int i;
>> +
>> + ALL_DEBUG_REGISTERS(i)
>> + {
>> + state->dr_mirror[i] = 0;
>> + state->dr_ref_count[i] = 0;
>> + }
>> + state->dr_control_mirror = 0;
>> + state->dr_status_mirror = 0;
>> +}
>
> This isn't called anywhere?
Ah. 'tis now.
>> +
>> +/* Print the values of the mirrored debug registers. This is called
>> + when maint_show_dr is non-zero.
>
>> To set that up, type "maint
>> + show-debug-regs" at GDB's prompt. */
>
> Nope, this is a lie.
fixed.
>> +
>> +static void
>> +i386_show_dr (struct i386_debug_reg_state *state,
>> + const char *func, CORE_ADDR addr,
>> + int len, enum target_hw_bp_type type)
>> +{
>> + int i;
>> +
>> + printf (func);
>> + if (addr || len)
>> + printf (" (addr=%lx, len=%d, type=%s)",
>> + (unsigned long) addr, len,
>> + type == hw_write ? "data-write"
>> + : (type == hw_read ? "data-read"
>> + : (type == hw_access ? "data-read/write"
>> + : (type == hw_execute ? "instruction-execute"
>> + /* FIXME: if/when I/O read/write
>> + watchpoints are supported, add them
>> + here. */
>> + : "??unknown??"))));
>> + printf (":\n");
>> + printf ("\tCONTROL (DR7): %08x STATUS (DR6): %08x\n",
>> + state->dr_control_mirror, state->dr_status_mirror);
>> + ALL_DEBUG_REGISTERS (i)
>> + {
>> + printf ("\
>> +\tDR%d: addr=0x%s, ref.count=%d DR%d: addr=0x%s, ref.count=%d\n",
>> + i, paddr (state->dr_mirror[i]), state->dr_ref_count[i],
>> + i+1, paddr (state->dr_mirror[i+1]), state->dr_ref_count[i+1]);
>> + i++;
>> + }
>> +}
>
> These should not go to stdout. GDB should be fixed too to make these go to
> gdb_stdlog.
changed to stderr
>> +
>> +static int
>> +Z_packet_to_hw_type (char type)
>> +{
>> + switch (type)
>> + {
>> + case Z_PACKET_WRITE_WP: return hw_write;
>> + case Z_PACKET_READ_WP: return hw_read;
>> + case Z_PACKET_ACCESS_WP: return hw_access;
>
> Please don't vertically align. Stick to the standards and put
> those return statements in their own line.
k.
>> + default:
>> + error ("Z_packet_to_hw_type: bad watchpoint type %c", type);
>> + }
>> +}
>> +
>> +/* Insert a watchpoint to watch a memory region which starts at
>> + address ADDR and whose length is LEN bytes. Watch memory accesses
>> + of the type TYPE_FROM_PACKET. Return 0 on success, -1 on failure. */
>> +
>> +int
>> +i386_low_insert_watchpoint (struct i386_debug_reg_state *state,
>> + char type_from_packet, CORE_ADDR addr, int len)
>> +{
>> + int retval;
>> + int type = Z_packet_to_hw_type (type_from_packet);
>> +
>> + if (((len != 1 && len !=2 && len !=4) && !(TARGET_HAS_DR_LEN_8 && len == 8))
>
> More examples of missing space around operators coming from GDB.
patch updated
>> +
>> +/* If the inferior has some watchpoint that triggered, set the
>> + address associated with that watchpoint and return non-zero.
>> + Otherwise, return zero. */
>> +
>> +CORE_ADDR
>> +i386_low_stopped_data_address (struct i386_debug_reg_state *state)
>> +{
>> + CORE_ADDR addr = 0;
>> + int i;
>> +
>> + /* Get dr_status_mirror for use by I386_DR_WATCH_HIT. */
>> + i386_dr_low_get_status (state);
>> +
>> + ALL_DEBUG_REGISTERS(i)
>> + {
>> + if (I386_DR_WATCH_HIT (state, i)
>> + /* This second condition makes sure DRi is set up for a data
>> + watchpoint, not a hardware breakpoint. The reason is
>> + that GDB doesn't call the target_stopped_data_address
>> + method except for data watchpoints. In other words, I'm
>> + being paranoiac. */
>> + && I386_DR_GET_RW_LEN (state, i) != 0)
>> + {
>> + addr = state->dr_mirror[i];
>> + if (maint_show_dr)
>> + i386_show_dr (state, "watchpoint_hit", addr, -1, hw_write);
>> + }
>> + }
>> +
>> + if (maint_show_dr && addr == 0)
>> + i386_show_dr (state, "stopped_data_addr", 0, 0, hw_write);
>> +
>
>> + /* NOTE: gdb version checks rc != 0 here. */
>> + return addr;
>> +}
>
> Indeed. GDB's interface was fixed to allow watchpoints at 0. I
> don't think that matters for any gdbserver target, but it would
> be nice to fix the interface anyway...
patch updated
>> +
>> +int
>> +i386_low_stopped_by_watchpoint (struct i386_debug_reg_state *state)
>> +{
>> + CORE_ADDR addr = 0;
>> + /* NOTE: gdb version passes boolean found/not-found result from
>> + i386_stopped_data_address. */
>> + addr = i386_low_stopped_data_address (state);
>> + return (addr != 0);
>> +}
>
> Same as above. You've probably thought about that too...
>
>> +
>> +/* Support for h/w breakpoints.
>> + This support is not currently used, kept for reference. */
>
> Any reason for not using this currently? If there's a good reason,
> than let's drop it. But I'd prefer to have it working. :-)
deleted.
>> Index: utils.c
>> ===================================================================
>
> +char *
> +paddr (CORE_ADDR addr)
>
> This isn't documented in neither server.h or here?
Just "going with the flow".
> +{
> + char *str = get_cell ();
> + xsnprintf (str, CELLSIZE, "%lx", (long) addr);
>
> ^^^^
>
> Note: this will be wrong on Win64... BTW, Ulrich
> was removing several of these functions from GDB
> in the removing-current_gdbarch series. Will this one
> stay? Might be worth it to use the one that is going
> to stay in GDB.
I think a higher order bit is that gdb and gdbserver cannot share
code. Bringing over all the smarts to handle all the different
portability issues is painful/depressing. I went with something
simple that works for now.
IWBN if this kind of thing were in, say, libiberty and tools could just use it.
>
> + return str;
> +}
>
>
>
>> Index: linux-low.c
>> ===================================================================
>> RCS file: /cvs/src/src/gdb/gdbserver/linux-low.c,v
>> retrieving revision 1.105
>> diff -u -p -r1.105 linux-low.c
>> --- linux-low.c 24 May 2009 17:44:19 -0000 1.105
>> +++ linux-low.c 1 Jun 2009 22:02:43 -0000
>> @@ -224,6 +224,7 @@ delete_lwp (struct lwp_info *lwp)
>> {
>> remove_thread (get_lwp_thread (lwp));
>> remove_inferior (&all_lwps, &lwp->head);
>> + free (lwp->arch_private);
>> free (lwp);
>> }
>>
>> @@ -242,6 +243,9 @@ linux_add_process (int pid, int attached
>> proc = add_process (pid, attached);
>> proc->private = xcalloc (1, sizeof (*proc->private));
>>
>> + if (the_low_target.new_process != NULL)
>> + proc->private->arch_private = the_low_target.new_process (pid, attached);
>
> ( Wouldn't the interface be a bit cleaner if you
> passed the 'proc' pointer down to new_process, and have the
> callback manage arch_private field itself? As is, your passing
> some useless parameters down. If they end up being needed,
> it is likely that an extra look up on pid would be needed to
> get at the structure. This would also migrate better to a
> per-process data mechanism similar to gdb's objfile_data, if
> need be. )
args deleted.
>> Index: linux-low.h
>> ===================================================================
>> RCS file: /cvs/src/src/gdb/gdbserver/linux-low.h,v
>> retrieving revision 1.30
>> diff -u -p -r1.30 linux-low.h
>> --- linux-low.h 12 May 2009 22:25:00 -0000 1.30
>> +++ linux-low.h 1 Jun 2009 22:02:43 -0000
>> @@ -56,8 +56,13 @@ struct process_info_private
>>
>> /* Connection to the libthread_db library. */
>> td_thragent_t *thread_agent;
>> +
>> + /* Target-specific additions. */
>
> Warning: "Target" overload. We need to get into the habit
> of not doing this --- it makes refering to these things quite
> ambiguous. Call it "arch" or something else. There are other
> similar cases.
I dunno. there's "the_low_target" in linux-low.h
Perhaps we can migrate away but I don't see the above "infraction" as
being critical.
>> #define pid_of(proc) ptid_get_pid ((proc)->head.id)
>> #define lwpid_of(proc) ptid_get_lwp ((proc)->head.id)
>> +#define PIDGET(ptid) ptid_get_pid (ptid)
>> +#define TIDGET(ptid) ptid_get_lwp (ptid)
>
> Why do we need extra ways to do the same thing? Let's not
> copy GDB's bad habits and legacy code.
k.
>> --- linux-x86-low.c 13 May 2009 19:11:04 -0000 1.2
>> +++ linux-x86-low.c 1 Jun 2009 22:02:43 -0000
>
>> +static unsigned long
>> +x86_linux_dr_get (ptid_t ptid, int regnum)
>> +{
>> + int tid;
>> + unsigned long value;
>> +
>> + tid = TIDGET (ptid);
>> + if (tid == 0)
>> + tid = PIDGET (ptid);
>
> The tid == 0 case is dead code coming from GDB, isn't it?
> Likewise in other places.
Perhaps. There's similar code in linux-low.c:same_lwp.
== 0 code deleted.
>> +
>> + errno = 0;
>> + value = ptrace (PTRACE_PEEKUSER, tid,
>> + offsetof (struct user, u_debugreg[regnum]), 0);
>> + if (errno != 0)
>> + error ("Couldn't read debug register");
>> +
>> + return value;
>> +}
>> +
>
>> +/* Update the inferior's debug register REGNUM from STATE. */
>> +
>> +void
>> +i386_dr_low_set_addr (const struct i386_debug_reg_state *state, int regnum)
>> +{
>> + struct inferior_list_entry *lp;
>> + CORE_ADDR addr;
>> +
>> + if (! (regnum >= 0 && regnum <= DR_LASTADDR - DR_FIRSTADDR))
>> + fatal ("Invalid debug register %d", regnum);
>> +
>> + addr = state->dr_mirror[regnum];
>> +
>> + /* ??? Will need tweaking for multi-process. */
>
> Indeed. Why not just set the debug_registers_changed in lwps
> of the current process?
Are there any existing examples of this?
I would have done that had process_info contained the list of its
threads (it would have been trivially straightforward).
>> + for (lp = all_lwps.head; lp; lp = lp->next)
>> + {
>> + struct lwp_info *lwp = (struct lwp_info *) lp;
>> +
>> + /* The actual update is done later, we just mark that the register
>> + needs updating. */
>> + lwp->arch_private->debug_registers_changed = 1;
>> + }
>
> Thanks, this is likely more non-stop friendly than the win32 version.
> We can just send a SIGSTOP to each thread that is stopped, and set
> stop_expected. Then, the debug register updating just works. (we'll
> still need to make sure that moribund locations work with watchpoints
> though)
>
>
>> Index: utils.c
>> ===================================================================
>> RCS file: /cvs/src/src/gdb/gdbserver/utils.c,v
>> retrieving revision 1.18
>> diff -u -p -r1.18 utils.c
>> --- utils.c 19 Jan 2009 00:16:46 -0000 1.18
>> +++ utils.c 1 Jun 2009 22:02:43 -0000
>> @@ -170,3 +170,37 @@ warning (const char *string,...)
>> fprintf (stderr, "\n");
>> va_end (args);
>> }
>> +
>> +/* temporary storage using circular buffer */
>
> More bogus formatting copied from GDB. Full sentence: capitalize, period,
> double space.
k.
>> +#define NUMCELLS 4
>> +#define CELLSIZE 50
>> +static char *
>> +get_cell (void)
>> +{
>> + static char buf[NUMCELLS][CELLSIZE];
>> + static int cell = 0;
>> + if (++cell >= NUMCELLS)
>> + cell = 0;
>> + return buf[cell];
>> +}
>> +
>
>
> Otherwise, this is looking good to me. I still feel that
> exposing the debug registers to GDB (as per-process wide
> registers), as opposed to using Z packets would be an
> alternative worth investigating, that would avoid having
> to mostly copy i386-nat.c to gdbserver/i386-low.c. But,
> the Z packets interface already exists, so, that can
> always be investigated at any later time...
Setting aside breakpoints+watchpoints -> "points",
http://sourceware.org/ml/gdb-patches/2009-06/msg00594.html
how about this?
[-- Attachment #2: gdb-090622-gdbserver-hw-wp-4.patch.txt --]
[-- Type: text/plain, Size: 51943 bytes --]
2009-06-22 Doug Evans <dje@google.com>
Pierre Muller <muller@ics.u-strasbg.fr>
* Makefile.in (SFILES): Add i386-low.c
(i386_low_h): Define.
(i386-low.o): Add dependencies.
(linux-x86-low.o): Add i386-low.h dependency.
(win32-i386-low.o): Ditto.
* i386-low.c: New file.
* i386-low.h: New file.
* configure.srv (i[34567]86-*-cygwin*): Add i386-low.o to srv_tgtobj.
(i[34567]86-*-linux*, i[34567]86-*-mingw*, x86_64-*-linux*): Ditto.
* linux-low.c (linux_add_process): Initialize arch_private.
(linux_remove_process): Free arch_private.
(add_lwp): Initialize arch_private.
(delete_lwp): Free arch_private.
(linux_resume_one_lwp): Call the_low_target.prepare_to_resume if
provided.
* linux-low.h (process_info_private): New member arch_private.
(lwp_info): New member arch_private.
(linux_target_ops): New members new_process, new_thread,
prepare_to_resume.
(ptid_of): New macro.
* linux-x86-low.c: Include stddef.h, i386-low.h.
(arch_process_info): New struct.
(arch_lwp_info): New struct.
(x86_linux_dr_get, x86_linux_dr_set): New functions.
(i386_dr_low_set_addr, i386_dr_low_set_control): New functions.
(i386_dr_low_get_status): New function.
(x86_insert_watchpoint, x86_remove_watchpoint): New functions.
(x86_stopped_by_watchpoint): New function.
(x86_stopped_data_address): New function.
(x86_linux_new_process, x86_linux_new_thread): New functions.
(x86_linux_prepare_to_resume): New function.
(the_low_target): Add entries for insert_watchpoint, remove_watchpoint,
stopped_by_watchpoint, stopped_data_address, new_process, new_thread,
prepare_to_resume.
* server.c (debug_hw_points): New global.
(monitor_show_help): Document set debug-hw-points.
* server.h (debug_hw_points): Declare.
(paddr): Declare.
* utils.c (NUMCELLS, CELLSIZE): New macros.
(get_sell, xsnprintf, paddr): New functions.
* win32-arm-low.c (the_low_target): Add entries for insert_watchpoint,
remove_watchpoint, stopped_by_watchpoint, stopped_data_address.
* win32-i386-low.c: Include i386-low.h.
(debug_reg_state): Replaces dr.
(i386_dr_low_set_addr, i386_dr_low_set_control): New functions.
(i386_dr_low_get_status): New function.
(i386_insert_watchpoint, i386_remove_watchpoint): New functions.
(i386_stopped_by_watchpoint): New function.
(i386_stopped_data_address): New function.
(i386_initial_stuff): Update.
(get_thread_context,set_thread_context,i386_thread_added): Update.
(the_low_target): Add entries for insert_watchpoint,
remove_watchpoint, stopped_by_watchpoint, stopped_data_address.
* win32-low.c (win32_insert_watchpoint): New function.
(win32_remove_watchpoint): New function.
(win32_stopped_by_watchpoint): New function.
(win32_stopped_data_address): New function.
(win32_target_ops): Add entries for insert_watchpoint,
remove_watchpoint, stopped_by_watchpoint, stopped_data_address.
* win32-low.h (win32_target_ops): New members insert_watchpoint,
remove_watchpoint, stopped_by_watchpoint, stopped_data_address.
Index: Makefile.in
===================================================================
RCS file: /cvs/src/src/gdb/gdbserver/Makefile.in,v
retrieving revision 1.74
diff -u -p -r1.74 Makefile.in
--- Makefile.in 12 May 2009 22:25:00 -0000 1.74
+++ Makefile.in 23 Jun 2009 06:35:45 -0000
@@ -104,7 +104,7 @@ SFILES= $(srcdir)/gdbreplay.c $(srcdir)/
$(srcdir)/thread-db.c $(srcdir)/utils.c \
$(srcdir)/linux-arm-low.c $(srcdir)/linux-cris-low.c \
$(srcdir)/linux-crisv32-low.c \
- $(srcdir)/i387-fp.c \
+ ${srcdir}/i386-low.c $(srcdir)/i387-fp.c \
$(srcdir)/linux-ia64-low.c $(srcdir)/linux-low.c \
$(srcdir)/linux-m32r-low.c \
$(srcdir)/linux-m68k-low.c $(srcdir)/linux-mips-low.c \
@@ -287,6 +287,10 @@ signals.o: ../common/signals.c $(server_
memmem.o: ../gnulib/memmem.c
$(CC) -o memmem.o -c $(CPPFLAGS) $(INTERNAL_CFLAGS) $<
+i386_low_h = $(srcdir)/i386-low.h
+
+i386-low.o: i386-low.c $(i386_low_h) $(server_h) $(target_h)
+
i387-fp.o: i387-fp.c $(server_h)
linux-low.o: linux-low.c $(linux_low_h) $(server_h)
@@ -304,7 +308,7 @@ linux-ppc-low.o: linux-ppc-low.c $(linux
linux-s390-low.o: linux-s390-low.c $(linux_low_h) $(server_h)
linux-sh-low.o: linux-sh-low.c $(linux_low_h) $(server_h)
linux-x86-low.o: linux-x86-low.c $(linux_low_h) $(server_h) \
- $(gdb_proc_service_h)
+ $(gdb_proc_service_h) $(i386_low_h)
linux-xtensa-low.o: linux-xtensa-low.c xtensa-xtregs.c $(linux_low_h) $(server_h)
win32_low_h = $(srcdir)/win32-low.h
@@ -312,7 +316,7 @@ win32_low_h = $(srcdir)/win32-low.h
win32-low.o: win32-low.c $(win32_low_h) $(server_h) $(regdef_h) $(regcache_h)
win32-arm-low.o: win32-arm-low.c $(win32_low_h) $(server_h)
-win32-i386-low.o: win32-i386-low.c $(win32_low_h) $(server_h)
+win32-i386-low.o: win32-i386-low.c $(win32_low_h) $(server_h) $(i386_low_h)
spu-low.o: spu-low.c $(server_h)
Index: configure.srv
===================================================================
RCS file: /cvs/src/src/gdb/gdbserver/configure.srv,v
retrieving revision 1.41
diff -u -p -r1.41 configure.srv
--- configure.srv 12 May 2009 22:25:00 -0000 1.41
+++ configure.srv 23 Jun 2009 06:35:45 -0000
@@ -53,10 +53,10 @@ case "${target}" in
srv_linux_thread_db=yes
;;
i[34567]86-*-cygwin*) srv_regobj=reg-i386.o
- srv_tgtobj="win32-low.o win32-i386-low.o"
+ srv_tgtobj="i386-low.o win32-low.o win32-i386-low.o"
;;
i[34567]86-*-linux*) srv_regobj=reg-i386-linux.o
- srv_tgtobj="linux-low.o linux-x86-low.o i387-fp.o"
+ srv_tgtobj="linux-low.o linux-x86-low.o i386-low.o i387-fp.o"
srv_linux_usrregs=yes
srv_linux_regsets=yes
srv_linux_thread_db=yes
@@ -71,7 +71,7 @@ case "${target}" in
srv_mingwce=yes
;;
i[34567]86-*-mingw*) srv_regobj=reg-i386.o
- srv_tgtobj="win32-low.o win32-i386-low.o"
+ srv_tgtobj="i386-low.o win32-low.o win32-i386-low.o"
srv_mingw=yes
;;
ia64-*-linux*) srv_regobj=reg-ia64.o
@@ -170,7 +170,7 @@ case "${target}" in
srv_tgtobj="spu-low.o"
;;
x86_64-*-linux*) srv_regobj="reg-x86-64-linux.o reg-i386-linux.o"
- srv_tgtobj="linux-low.o linux-x86-low.o i387-fp.o"
+ srv_tgtobj="linux-low.o linux-x86-low.o i386-low.o i387-fp.o"
srv_linux_usrregs=yes # This is for i386 progs.
srv_linux_regsets=yes
srv_linux_thread_db=yes
Index: i386-low.c
===================================================================
RCS file: i386-low.c
diff -N i386-low.c
--- /dev/null 1 Jan 1970 00:00:00 -0000
+++ i386-low.c 23 Jun 2009 06:35:45 -0000
@@ -0,0 +1,575 @@
+/* Debug register code for the i386.
+
+ Copyright (C) 2009
+ Free Software Foundation, Inc.
+
+ This file is part of GDB.
+
+ This program is free software; you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation; either version 3 of the License, or
+ (at your option) any later version.
+
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program. If not, see <http://www.gnu.org/licenses/>. */
+
+#include "server.h"
+#include "target.h"
+#include "i386-low.h"
+
+/* Support for 8-byte wide hw watchpoints. */
+#ifndef TARGET_HAS_DR_LEN_8
+/* NOTE: sizeof (long) == 4 on win64. */
+#define TARGET_HAS_DR_LEN_8 (sizeof (void *) == 8)
+#endif
+
+enum target_hw_bp_type
+ {
+ hw_write = 0, /* Common HW watchpoint */
+ hw_read = 1, /* Read HW watchpoint */
+ hw_access = 2, /* Access HW watchpoint */
+ hw_execute = 3 /* Execute HW breakpoint */
+ };
+
+/* DR7 Debug Control register fields. */
+
+/* How many bits to skip in DR7 to get to R/W and LEN fields. */
+#define DR_CONTROL_SHIFT 16
+/* How many bits in DR7 per R/W and LEN field for each watchpoint. */
+#define DR_CONTROL_SIZE 4
+
+/* Watchpoint/breakpoint read/write fields in DR7. */
+#define DR_RW_EXECUTE (0x0) /* Break on instruction execution. */
+#define DR_RW_WRITE (0x1) /* Break on data writes. */
+#define DR_RW_READ (0x3) /* Break on data reads or writes. */
+
+/* This is here for completeness. No platform supports this
+ functionality yet (as of March 2001). Note that the DE flag in the
+ CR4 register needs to be set to support this. */
+#ifndef DR_RW_IORW
+#define DR_RW_IORW (0x2) /* Break on I/O reads or writes. */
+#endif
+
+/* Watchpoint/breakpoint length fields in DR7. The 2-bit left shift
+ is so we could OR this with the read/write field defined above. */
+#define DR_LEN_1 (0x0 << 2) /* 1-byte region watch or breakpoint. */
+#define DR_LEN_2 (0x1 << 2) /* 2-byte region watch. */
+#define DR_LEN_4 (0x3 << 2) /* 4-byte region watch. */
+#define DR_LEN_8 (0x2 << 2) /* 8-byte region watch (AMD64). */
+
+/* Local and Global Enable flags in DR7.
+
+ When the Local Enable flag is set, the breakpoint/watchpoint is
+ enabled only for the current task; the processor automatically
+ clears this flag on every task switch. When the Global Enable flag
+ is set, the breakpoint/watchpoint is enabled for all tasks; the
+ processor never clears this flag.
+
+ Currently, all watchpoint are locally enabled. If you need to
+ enable them globally, read the comment which pertains to this in
+ i386_insert_aligned_watchpoint below. */
+#define DR_LOCAL_ENABLE_SHIFT 0 /* Extra shift to the local enable bit. */
+#define DR_GLOBAL_ENABLE_SHIFT 1 /* Extra shift to the global enable bit. */
+#define DR_ENABLE_SIZE 2 /* Two enable bits per debug register. */
+
+/* Local and global exact breakpoint enable flags (a.k.a. slowdown
+ flags). These are only required on i386, to allow detection of the
+ exact instruction which caused a watchpoint to break; i486 and
+ later processors do that automatically. We set these flags for
+ backwards compatibility. */
+#define DR_LOCAL_SLOWDOWN (0x100)
+#define DR_GLOBAL_SLOWDOWN (0x200)
+
+/* Fields reserved by Intel. This includes the GD (General Detect
+ Enable) flag, which causes a debug exception to be generated when a
+ MOV instruction accesses one of the debug registers.
+
+ FIXME: My Intel manual says we should use 0xF800, not 0xFC00. */
+#define DR_CONTROL_RESERVED (0xFC00)
+
+/* Auxiliary helper macros. */
+
+/* A value that masks all fields in DR7 that are reserved by Intel. */
+#define I386_DR_CONTROL_MASK (~DR_CONTROL_RESERVED)
+
+/* The I'th debug register is vacant if its Local and Global Enable
+ bits are reset in the Debug Control register. */
+#define I386_DR_VACANT(state, i) \
+ (((state)->dr_control_mirror & (3 << (DR_ENABLE_SIZE * (i)))) == 0)
+
+/* Locally enable the break/watchpoint in the I'th debug register. */
+#define I386_DR_LOCAL_ENABLE(state, i) \
+ do { \
+ (state)->dr_control_mirror |= \
+ (1 << (DR_LOCAL_ENABLE_SHIFT + DR_ENABLE_SIZE * (i))); \
+ } while (0)
+
+/* Globally enable the break/watchpoint in the I'th debug register. */
+#define I386_DR_GLOBAL_ENABLE(state, i) \
+ do { \
+ (state)->dr_control_mirror |= \
+ (1 << (DR_GLOBAL_ENABLE_SHIFT + DR_ENABLE_SIZE * (i))); \
+ } while (0)
+
+/* Disable the break/watchpoint in the I'th debug register. */
+#define I386_DR_DISABLE(state, i) \
+ do { \
+ (state)->dr_control_mirror &= \
+ ~(3 << (DR_ENABLE_SIZE * (i))); \
+ } while (0)
+
+/* Set in DR7 the RW and LEN fields for the I'th debug register. */
+#define I386_DR_SET_RW_LEN(state, i,rwlen) \
+ do { \
+ (state)->dr_control_mirror &= \
+ ~(0x0f << (DR_CONTROL_SHIFT + DR_CONTROL_SIZE * (i))); \
+ (state)->dr_control_mirror |= \
+ ((rwlen) << (DR_CONTROL_SHIFT + DR_CONTROL_SIZE * (i))); \
+ } while (0)
+
+/* Get from DR7 the RW and LEN fields for the I'th debug register. */
+#define I386_DR_GET_RW_LEN(state, i) \
+ (((state)->dr_control_mirror \
+ >> (DR_CONTROL_SHIFT + DR_CONTROL_SIZE * (i))) & 0x0f)
+
+/* Did the watchpoint whose address is in the I'th register break? */
+#define I386_DR_WATCH_HIT(state,i) ((state)->dr_status_mirror & (1 << (i)))
+
+/* A macro to loop over all debug registers. */
+#define ALL_DEBUG_REGISTERS(i) for (i = 0; i < DR_NADDR; i++)
+
+/* Types of operations supported by i386_handle_nonaligned_watchpoint. */
+typedef enum { WP_INSERT, WP_REMOVE, WP_COUNT } i386_wp_op_t;
+\f
+/* Implementation. */
+
+/* Clear the reference counts and forget everything we knew about the
+ debug registers. */
+
+void
+i386_low_init_dregs (struct i386_debug_reg_state *state)
+{
+ int i;
+
+ ALL_DEBUG_REGISTERS (i)
+ {
+ state->dr_mirror[i] = 0;
+ state->dr_ref_count[i] = 0;
+ }
+ state->dr_control_mirror = 0;
+ state->dr_status_mirror = 0;
+}
+
+/* Print the values of the mirrored debug registers. This is enabled via
+ the "set debug-hw-points 1" monitor command. */
+
+static void
+i386_show_dr (struct i386_debug_reg_state *state,
+ const char *func, CORE_ADDR addr,
+ int len, enum target_hw_bp_type type)
+{
+ int i;
+
+ fprintf (stderr, "%s", func);
+ if (addr || len)
+ fprintf (stderr, " (addr=%lx, len=%d, type=%s)",
+ (unsigned long) addr, len,
+ type == hw_write ? "data-write"
+ : (type == hw_read ? "data-read"
+ : (type == hw_access ? "data-read/write"
+ : (type == hw_execute ? "instruction-execute"
+ /* FIXME: if/when I/O read/write
+ watchpoints are supported, add them
+ here. */
+ : "??unknown??"))));
+ fprintf (stderr, ":\n");
+ fprintf (stderr, "\tCONTROL (DR7): %08x STATUS (DR6): %08x\n",
+ state->dr_control_mirror, state->dr_status_mirror);
+ ALL_DEBUG_REGISTERS (i)
+ {
+ fprintf (stderr, "\
+\tDR%d: addr=0x%s, ref.count=%d DR%d: addr=0x%s, ref.count=%d\n",
+ i, paddr (state->dr_mirror[i]),
+ state->dr_ref_count[i],
+ i + 1, paddr (state->dr_mirror[i + 1]),
+ state->dr_ref_count[i + 1]);
+ i++;
+ }
+}
+
+/* Return the value of a 4-bit field for DR7 suitable for watching a
+ region of LEN bytes for accesses of type TYPE. LEN is assumed to
+ have the value of 1, 2, or 4. */
+
+static unsigned
+i386_length_and_rw_bits (int len, enum target_hw_bp_type type)
+{
+ unsigned rw;
+
+ switch (type)
+ {
+ case hw_execute:
+ rw = DR_RW_EXECUTE;
+ break;
+ case hw_write:
+ rw = DR_RW_WRITE;
+ break;
+ case hw_read:
+ /* The i386 doesn't support data-read watchpoints. */
+ case hw_access:
+ rw = DR_RW_READ;
+ break;
+#if 0
+ /* Not yet supported. */
+ case hw_io_access:
+ rw = DR_RW_IORW;
+ break;
+#endif
+ default:
+ error ("\
+Invalid hardware breakpoint type %d in i386_length_and_rw_bits.\n",
+ (int) type);
+ }
+
+ switch (len)
+ {
+ case 1:
+ return (DR_LEN_1 | rw);
+ case 2:
+ return (DR_LEN_2 | rw);
+ case 4:
+ return (DR_LEN_4 | rw);
+ case 8:
+ if (TARGET_HAS_DR_LEN_8)
+ return (DR_LEN_8 | rw);
+ default:
+ error ("\
+Invalid hardware breakpoint length %d in i386_length_and_rw_bits.\n", len);
+ }
+}
+
+/* Insert a watchpoint at address ADDR, which is assumed to be aligned
+ according to the length of the region to watch. LEN_RW_BITS is the
+ value of the bits from DR7 which describes the length and access
+ type of the region to be watched by this watchpoint. Return 0 on
+ success, -1 on failure. */
+
+static int
+i386_insert_aligned_watchpoint (struct i386_debug_reg_state *state,
+ CORE_ADDR addr, unsigned len_rw_bits)
+{
+ int i;
+
+ /* First, look for an occupied debug register with the same address
+ and the same RW and LEN definitions. If we find one, we can
+ reuse it for this watchpoint as well (and save a register). */
+ ALL_DEBUG_REGISTERS (i)
+ {
+ if (!I386_DR_VACANT (state, i)
+ && state->dr_mirror[i] == addr
+ && I386_DR_GET_RW_LEN (state, i) == len_rw_bits)
+ {
+ state->dr_ref_count[i]++;
+ return 0;
+ }
+ }
+
+ /* Next, look for a vacant debug register. */
+ ALL_DEBUG_REGISTERS (i)
+ {
+ if (I386_DR_VACANT (state, i))
+ break;
+ }
+
+ /* No more debug registers! */
+ if (i >= DR_NADDR)
+ return -1;
+
+ /* Now set up the register I to watch our region. */
+
+ /* Record the info in our local mirrored array. */
+ state->dr_mirror[i] = addr;
+ state->dr_ref_count[i] = 1;
+ I386_DR_SET_RW_LEN (state, i, len_rw_bits);
+ /* Note: we only enable the watchpoint locally, i.e. in the current
+ task. Currently, no i386 target allows or supports global
+ watchpoints; however, if any target would want that in the
+ future, GDB should probably provide a command to control whether
+ to enable watchpoints globally or locally, and the code below
+ should use global or local enable and slow-down flags as
+ appropriate. */
+ I386_DR_LOCAL_ENABLE (state, i);
+ state->dr_control_mirror |= DR_LOCAL_SLOWDOWN;
+ state->dr_control_mirror &= I386_DR_CONTROL_MASK;
+
+ /* Finally, actually pass the info to the inferior. */
+ i386_dr_low_set_addr (state, i);
+ i386_dr_low_set_control (state);
+
+ return 0;
+}
+
+/* Remove a watchpoint at address ADDR, which is assumed to be aligned
+ according to the length of the region to watch. LEN_RW_BITS is the
+ value of the bits from DR7 which describes the length and access
+ type of the region watched by this watchpoint. Return 0 on
+ success, -1 on failure. */
+
+static int
+i386_remove_aligned_watchpoint (struct i386_debug_reg_state *state,
+ CORE_ADDR addr, unsigned len_rw_bits)
+{
+ int i, retval = -1;
+
+ ALL_DEBUG_REGISTERS (i)
+ {
+ if (!I386_DR_VACANT (state, i)
+ && state->dr_mirror[i] == addr
+ && I386_DR_GET_RW_LEN (state, i) == len_rw_bits)
+ {
+ if (--state->dr_ref_count[i] == 0) /* No longer in use? */
+ {
+ /* Reset our mirror. */
+ state->dr_mirror[i] = 0;
+ I386_DR_DISABLE (state, i);
+ /* Reset it in the inferior. */
+ i386_dr_low_set_control (state);
+ i386_dr_low_set_addr (state, i);
+ }
+ retval = 0;
+ }
+ }
+
+ return retval;
+}
+
+/* Insert or remove a (possibly non-aligned) watchpoint, or count the
+ number of debug registers required to watch a region at address
+ ADDR whose length is LEN for accesses of type TYPE. Return 0 on
+ successful insertion or removal, a positive number when queried
+ about the number of registers, or -1 on failure. If WHAT is not a
+ valid value, bombs through internal_error. */
+
+static int
+i386_handle_nonaligned_watchpoint (struct i386_debug_reg_state *state,
+ i386_wp_op_t what, CORE_ADDR addr, int len,
+ enum target_hw_bp_type type)
+{
+ int retval = 0, status = 0;
+ int max_wp_len = TARGET_HAS_DR_LEN_8 ? 8 : 4;
+
+ static const int size_try_array[8][8] =
+ {
+ {1, 1, 1, 1, 1, 1, 1, 1}, /* Trying size one. */
+ {2, 1, 2, 1, 2, 1, 2, 1}, /* Trying size two. */
+ {2, 1, 2, 1, 2, 1, 2, 1}, /* Trying size three. */
+ {4, 1, 2, 1, 4, 1, 2, 1}, /* Trying size four. */
+ {4, 1, 2, 1, 4, 1, 2, 1}, /* Trying size five. */
+ {4, 1, 2, 1, 4, 1, 2, 1}, /* Trying size six. */
+ {4, 1, 2, 1, 4, 1, 2, 1}, /* Trying size seven. */
+ {8, 1, 2, 1, 4, 1, 2, 1}, /* Trying size eight. */
+ };
+
+ while (len > 0)
+ {
+ int align = addr % max_wp_len;
+ /* Four (eight on AMD64) is the maximum length a debug register
+ can watch. */
+ int try = (len > max_wp_len ? (max_wp_len - 1) : len - 1);
+ int size = size_try_array[try][align];
+
+ if (what == WP_COUNT)
+ {
+ /* size_try_array[] is defined such that each iteration
+ through the loop is guaranteed to produce an address and a
+ size that can be watched with a single debug register.
+ Thus, for counting the registers required to watch a
+ region, we simply need to increment the count on each
+ iteration. */
+ retval++;
+ }
+ else
+ {
+ unsigned len_rw = i386_length_and_rw_bits (size, type);
+
+ if (what == WP_INSERT)
+ status = i386_insert_aligned_watchpoint (state, addr, len_rw);
+ else if (what == WP_REMOVE)
+ status = i386_remove_aligned_watchpoint (state, addr, len_rw);
+ else
+ fatal ("\
+Invalid value %d of operation in i386_handle_nonaligned_watchpoint.\n",
+ (int) what);
+
+ /* We keep the loop going even after a failure, because some
+ of the other aligned watchpoints might still succeed
+ (e.g. if they watch addresses that are already watched,
+ in which case we just increment the reference counts of
+ occupied debug registers). If we break out of the loop
+ too early, we could cause those addresses watched by
+ other watchpoints to be disabled when breakpoint.c reacts
+ to our failure to insert this watchpoint and tries to
+ remove it. */
+ if (status)
+ retval = status;
+ }
+
+ addr += size;
+ len -= size;
+ }
+
+ return retval;
+}
+
+#define Z_PACKET_WRITE_WP '2'
+#define Z_PACKET_READ_WP '3'
+#define Z_PACKET_ACCESS_WP '4'
+
+static int
+Z_packet_to_hw_type (char type)
+{
+ switch (type)
+ {
+ case Z_PACKET_WRITE_WP:
+ return hw_write;
+ case Z_PACKET_READ_WP:
+ return hw_read;
+ case Z_PACKET_ACCESS_WP:
+ return hw_access;
+ default:
+ error ("Z_packet_to_hw_type: bad watchpoint type %c", type);
+ }
+}
+
+/* Insert a watchpoint to watch a memory region which starts at
+ address ADDR and whose length is LEN bytes. Watch memory accesses
+ of the type TYPE_FROM_PACKET. Return 0 on success, -1 on failure. */
+
+int
+i386_low_insert_watchpoint (struct i386_debug_reg_state *state,
+ char type_from_packet, CORE_ADDR addr, int len)
+{
+ int retval;
+ int type = Z_packet_to_hw_type (type_from_packet);
+
+ if (((len != 1 && len != 2 && len != 4)
+ && !(TARGET_HAS_DR_LEN_8 && len == 8))
+ || addr % len != 0)
+ {
+ retval = i386_handle_nonaligned_watchpoint (state, WP_INSERT,
+ addr, len, type);
+ }
+ else
+ {
+ unsigned len_rw = i386_length_and_rw_bits (len, type);
+
+ retval = i386_insert_aligned_watchpoint (state, addr, len_rw);
+ }
+
+ if (debug_hw_points)
+ i386_show_dr (state, "insert_watchpoint", addr, len, type);
+
+ return retval;
+}
+
+/* Remove a watchpoint that watched the memory region which starts at
+ address ADDR, whose length is LEN bytes, and for accesses of the
+ type TYPE_FROM_PACKET. Return 0 on success, -1 on failure. */
+
+int
+i386_low_remove_watchpoint (struct i386_debug_reg_state *state,
+ char type_from_packet, CORE_ADDR addr, int len)
+{
+ int retval;
+ int type = Z_packet_to_hw_type (type_from_packet);
+
+ if (((len != 1 && len != 2 && len != 4)
+ && !(TARGET_HAS_DR_LEN_8 && len == 8))
+ || addr % len != 0)
+ {
+ retval = i386_handle_nonaligned_watchpoint (state, WP_REMOVE,
+ addr, len, type);
+ }
+ else
+ {
+ unsigned len_rw = i386_length_and_rw_bits (len, type);
+
+ retval = i386_remove_aligned_watchpoint (state, addr, len_rw);
+ }
+
+ if (debug_hw_points)
+ i386_show_dr (state, "remove_watchpoint", addr, len, type);
+
+ return retval;
+}
+
+/* Return non-zero if we can watch a memory region that starts at
+ address ADDR and whose length is LEN bytes. */
+
+int
+i386_low_region_ok_for_watchpoint (struct i386_debug_reg_state *state,
+ CORE_ADDR addr, int len)
+{
+ int nregs;
+
+ /* Compute how many aligned watchpoints we would need to cover this
+ region. */
+ nregs = i386_handle_nonaligned_watchpoint (state, WP_COUNT,
+ addr, len, hw_write);
+ return nregs <= DR_NADDR ? 1 : 0;
+}
+
+/* If the inferior has some break/watchpoint that triggered, set the
+ address associated with that break/watchpoint and return true.
+ Otherwise, return false. */
+
+int
+i386_low_stopped_data_address (struct i386_debug_reg_state *state,
+ CORE_ADDR *addr_p)
+{
+ CORE_ADDR addr = 0;
+ int i;
+ int rc = 0;
+
+ /* Get dr_status_mirror for use by I386_DR_WATCH_HIT. */
+ i386_dr_low_get_status (state);
+
+ ALL_DEBUG_REGISTERS (i)
+ {
+ if (I386_DR_WATCH_HIT (state, i)
+ /* This second condition makes sure DRi is set up for a data
+ watchpoint, not a hardware breakpoint. The reason is
+ that GDB doesn't call the target_stopped_data_address
+ method except for data watchpoints. In other words, I'm
+ being paranoiac. */
+ && I386_DR_GET_RW_LEN (state, i) != 0)
+ {
+ addr = state->dr_mirror[i];
+ rc = 1;
+ if (debug_hw_points)
+ i386_show_dr (state, "watchpoint_hit", addr, -1, hw_write);
+ }
+ }
+
+ if (debug_hw_points && addr == 0)
+ i386_show_dr (state, "stopped_data_addr", 0, 0, hw_write);
+
+ if (rc)
+ *addr_p = addr;
+ return rc;
+}
+
+/* Return true if the inferior has some watchpoint that triggered.
+ Otherwise return false. */
+
+int
+i386_low_stopped_by_watchpoint (struct i386_debug_reg_state *state)
+{
+ CORE_ADDR addr = 0;
+ return i386_low_stopped_data_address (state, &addr);
+}
Index: i386-low.h
===================================================================
RCS file: i386-low.h
diff -N i386-low.h
--- /dev/null 1 Jan 1970 00:00:00 -0000
+++ i386-low.h 23 Jun 2009 06:35:45 -0000
@@ -0,0 +1,109 @@
+/* Misc. low level support for i386.
+
+ Copyright (C) 2009
+ Free Software Foundation, Inc.
+
+ This file is part of GDB.
+
+ This program is free software; you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation; either version 3 of the License, or
+ (at your option) any later version.
+
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program. If not, see <http://www.gnu.org/licenses/>. */
+
+/* Support for hardware watchpoints and breakpoints using the i386
+ debug registers.
+
+ This provides several functions for inserting and removing
+ hardware-assisted breakpoints and watchpoints, testing if one or
+ more of the watchpoints triggered and at what address, checking
+ whether a given region can be watched, etc.
+
+ The functions below implement debug registers sharing by reference
+ counts, and allow to watch regions up to 16 bytes long
+ (32 bytes on 64 bit hosts). */
+
+
+/* Debug registers' indices. */
+#define DR_FIRSTADDR 0
+#define DR_LASTADDR 3
+#define DR_NADDR 4 /* The number of debug address registers. */
+#define DR_STATUS 6
+#define DR_CONTROL 7
+
+/* Global state needed to track h/w watchpoints. */
+
+struct i386_debug_reg_state
+{
+ /* Mirror the inferior's DRi registers. We keep the status and
+ control registers separated because they don't hold addresses. */
+ CORE_ADDR dr_mirror[DR_NADDR];
+ unsigned dr_status_mirror, dr_control_mirror;
+
+ /* Reference counts for each debug register. */
+ int dr_ref_count[DR_NADDR];
+};
+
+/* Initialize STATE. */
+extern void i386_low_init_dregs (struct i386_debug_reg_state *state);
+
+/* Insert a watchpoint to watch a memory region which starts at
+ address ADDR and whose length is LEN bytes. Watch memory accesses
+ of the type TYPE_FROM_PACKET. Return 0 on success, -1 on failure. */
+extern int i386_low_insert_watchpoint (struct i386_debug_reg_state *state,
+ char type_from_packet, CORE_ADDR addr,
+ int len);
+
+/* Remove a watchpoint that watched the memory region which starts at
+ address ADDR, whose length is LEN bytes, and for accesses of the
+ type TYPE_FROM_PACKET. Return 0 on success, -1 on failure. */
+extern int i386_low_remove_watchpoint (struct i386_debug_reg_state *state,
+ char type_from_packet, CORE_ADDR addr,
+ int len);
+
+/* Return non-zero if we can watch a memory region that starts at
+ address ADDR and whose length is LEN bytes. */
+extern int i386_low_region_ok_for_watchpoint (struct i386_debug_reg_state *state,
+ CORE_ADDR addr, int len);
+
+/* If the inferior has some break/watchpoint that triggered, set the
+ address associated with that break/watchpoint and return true.
+ Otherwise, return false. */
+extern int i386_low_stopped_data_address (struct i386_debug_reg_state *state,
+ CORE_ADDR *addr_p);
+
+/* Return true if the inferior has some watchpoint that triggered.
+ Otherwise return false. */
+extern int i386_low_stopped_by_watchpoint (struct i386_debug_reg_state *state);
+\f
+/* Each target needs to provide several low-level functions
+ that will be called to insert watchpoints and hardware breakpoints
+ into the inferior, remove them, and check their status. These
+ functions are:
+
+ i386_dr_low_set_control -- set the debug control (DR7)
+ register to a given value
+
+ i386_dr_low_set_addr -- put an address into one debug register
+
+ i386_dr_low_get_status -- return the value of the debug
+ status (DR6) register.
+*/
+
+/* Update the inferior's debug register REGNUM from STATE. */
+extern void i386_dr_low_set_addr (const struct i386_debug_reg_state *state,
+ int regnum);
+
+/* Update the inferior's DR7 debug control register from STATE. */
+extern void i386_dr_low_set_control (const struct i386_debug_reg_state *state);
+
+/* Get the value of the inferior's DR6 debug status register
+ and record it in STATE. */
+extern void i386_dr_low_get_status (struct i386_debug_reg_state *state);
Index: linux-low.c
===================================================================
RCS file: /cvs/src/src/gdb/gdbserver/linux-low.c,v
retrieving revision 1.107
diff -u -p -r1.107 linux-low.c
--- linux-low.c 22 Jun 2009 19:33:41 -0000 1.107
+++ linux-low.c 23 Jun 2009 06:35:45 -0000
@@ -224,6 +224,7 @@ delete_lwp (struct lwp_info *lwp)
{
remove_thread (get_lwp_thread (lwp));
remove_inferior (&all_lwps, &lwp->head);
+ free (lwp->arch_private);
free (lwp);
}
@@ -242,6 +243,9 @@ linux_add_process (int pid, int attached
proc = add_process (pid, attached);
proc->private = xcalloc (1, sizeof (*proc->private));
+ if (the_low_target.new_process != NULL)
+ proc->private->arch_private = the_low_target.new_process ();
+
return proc;
}
@@ -251,6 +255,7 @@ linux_add_process (int pid, int attached
static void
linux_remove_process (struct process_info *process)
{
+ free (process->private->arch_private);
free (process->private);
remove_process (process);
}
@@ -376,6 +381,9 @@ add_lwp (ptid_t ptid)
lwp->head.id = ptid;
+ if (the_low_target.new_thread != NULL)
+ lwp->arch_private = the_low_target.new_thread ();
+
add_inferior_to_list (&all_lwps, &lwp->head);
return lwp;
@@ -466,7 +474,6 @@ linux_attach_lwp_1 (unsigned long lwpid,
new_lwp = (struct lwp_info *) add_lwp (ptid);
add_thread (ptid, new_lwp);
-
/* We need to wait for SIGSTOP before being able to make the next
ptrace call on this LWP. */
new_lwp->must_set_ptrace_flags = 1;
@@ -1740,6 +1747,9 @@ linux_resume_one_lwp (struct lwp_info *l
*p_sig = NULL;
}
+ if (the_low_target.prepare_to_resume != NULL)
+ the_low_target.prepare_to_resume (lwp);
+
regcache_invalidate_one ((struct inferior_list_entry *)
get_lwp_thread (lwp));
errno = 0;
Index: linux-low.h
===================================================================
RCS file: /cvs/src/src/gdb/gdbserver/linux-low.h,v
retrieving revision 1.30
diff -u -p -r1.30 linux-low.h
--- linux-low.h 12 May 2009 22:25:00 -0000 1.30
+++ linux-low.h 23 Jun 2009 06:35:45 -0000
@@ -56,8 +56,13 @@ struct process_info_private
/* Connection to the libthread_db library. */
td_thragent_t *thread_agent;
+
+ /* Target-specific additions. */
+ struct arch_process_info *arch_private;
};
+struct lwp_info;
+
struct linux_target_ops
{
/* Architecture-specific setup. */
@@ -96,10 +101,24 @@ struct linux_target_ops
If DIRECTION is 1, then copy from INF to NATIVE.
If DIRECTION is 0, copy from NATIVE to INF. */
int (*siginfo_fixup) (struct siginfo *native, void *inf, int direction);
+
+ /* Hook to call when a new process is created or attached to.
+ If the target needs per-process architecture-specific data,
+ allocate it here. */
+ struct arch_process_info * (*new_process) (void);
+
+ /* Hook to call when a new thread is detected.
+ If the target needs per-thread architecture-specific data,
+ allocate it here. */
+ struct arch_lwp_info * (*new_thread) (void);
+
+ /* Hook to call prior to resuming a thread. */
+ void (*prepare_to_resume) (struct lwp_info *);
};
extern struct linux_target_ops the_low_target;
+#define ptid_of(proc) ((proc)->head.id)
#define pid_of(proc) ptid_get_pid ((proc)->head.id)
#define lwpid_of(proc) ptid_get_lwp ((proc)->head.id)
@@ -172,6 +191,9 @@ struct lwp_info
THREAD_KNOWN is set. */
td_thrhandle_t th;
#endif
+
+ /* Target-specific additions. */
+ struct arch_lwp_info *arch_private;
};
extern struct inferior_list all_lwps;
Index: linux-x86-low.c
===================================================================
RCS file: /cvs/src/src/gdb/gdbserver/linux-x86-low.c,v
retrieving revision 1.2
diff -u -p -r1.2 linux-x86-low.c
--- linux-x86-low.c 13 May 2009 19:11:04 -0000 1.2
+++ linux-x86-low.c 23 Jun 2009 06:35:45 -0000
@@ -18,10 +18,12 @@
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>. */
+#include <stddef.h>
#include <signal.h>
#include "server.h"
#include "linux-low.h"
#include "i387-fp.h"
+#include "i386-low.h"
#include "gdb_proc_service.h"
@@ -56,6 +58,21 @@ void init_registers_x86_64_linux (void);
#define ARCH_GET_GS 0x1004
#endif
+/* Per-process arch-specific data we want to keep. */
+
+struct arch_process_info
+{
+ struct i386_debug_reg_state debug_reg_state;
+};
+
+/* Per-thread arch-specific data we want to keep. */
+
+struct arch_lwp_info
+{
+ /* Non-zero if our copy differs from what's recorded in the thread. */
+ int debug_registers_changed;
+};
+
#ifdef __x86_64__
/* Mapping between the general-purpose registers in `struct user'
@@ -317,6 +334,176 @@ x86_breakpoint_at (CORE_ADDR pc)
return 0;
}
\f
+/* Support for debug registers. */
+
+static unsigned long
+x86_linux_dr_get (ptid_t ptid, int regnum)
+{
+ int tid;
+ unsigned long value;
+
+ tid = ptid_get_lwp (ptid);
+
+ errno = 0;
+ value = ptrace (PTRACE_PEEKUSER, tid,
+ offsetof (struct user, u_debugreg[regnum]), 0);
+ if (errno != 0)
+ error ("Couldn't read debug register");
+
+ return value;
+}
+
+static void
+x86_linux_dr_set (ptid_t ptid, int regnum, unsigned long value)
+{
+ int tid;
+
+ tid = ptid_get_lwp (ptid);
+
+ errno = 0;
+ ptrace (PTRACE_POKEUSER, tid,
+ offsetof (struct user, u_debugreg[regnum]), value);
+ if (errno != 0)
+ error ("Couldn't write debug register");
+}
+
+/* Update the inferior's debug register REGNUM from STATE. */
+
+void
+i386_dr_low_set_addr (const struct i386_debug_reg_state *state, int regnum)
+{
+ struct inferior_list_entry *lp;
+ CORE_ADDR addr;
+
+ if (! (regnum >= 0 && regnum <= DR_LASTADDR - DR_FIRSTADDR))
+ fatal ("Invalid debug register %d", regnum);
+
+ addr = state->dr_mirror[regnum];
+
+ /* ??? Will need tweaking for multi-process. */
+ for (lp = all_lwps.head; lp; lp = lp->next)
+ {
+ struct lwp_info *lwp = (struct lwp_info *) lp;
+
+ /* The actual update is done later, we just mark that the register
+ needs updating. */
+ lwp->arch_private->debug_registers_changed = 1;
+ }
+}
+
+/* Update the inferior's DR7 debug control register from STATE. */
+
+void
+i386_dr_low_set_control (const struct i386_debug_reg_state *state)
+{
+ struct inferior_list_entry *lp;
+
+ /* ??? Will need tweaking for multi-process. */
+ for (lp = all_lwps.head; lp; lp = lp->next)
+ {
+ struct lwp_info *lwp = (struct lwp_info *) lp;
+
+ /* The actual update is done later, we just mark that the register
+ needs updating. */
+ lwp->arch_private->debug_registers_changed = 1;
+ }
+}
+
+/* Get the value of the DR6 debug status register from the inferior
+ and record it in STATE. */
+
+void
+i386_dr_low_get_status (struct i386_debug_reg_state *state)
+{
+ struct lwp_info *lwp = get_thread_lwp (current_inferior);
+ ptid_t ptid = ptid_of (lwp);
+
+ state->dr_status_mirror = x86_linux_dr_get (ptid, DR_STATUS);
+}
+\f
+/* Watchpoint support. */
+
+static int
+x86_insert_watchpoint (char type, CORE_ADDR addr, int len)
+{
+ struct process_info *proc = current_process ();
+ return i386_low_insert_watchpoint (&proc->private->arch_private->debug_reg_state,
+ type, addr, len);
+}
+
+static int
+x86_remove_watchpoint (char type, CORE_ADDR addr, int len)
+{
+ struct process_info *proc = current_process ();
+ return i386_low_remove_watchpoint (&proc->private->arch_private->debug_reg_state,
+ type, addr, len);
+}
+
+static int
+x86_stopped_by_watchpoint (void)
+{
+ struct process_info *proc = current_process ();
+ return i386_low_stopped_by_watchpoint (&proc->private->arch_private->debug_reg_state);
+}
+
+static CORE_ADDR
+x86_stopped_data_address (void)
+{
+ struct process_info *proc = current_process ();
+ CORE_ADDR addr;
+ if (i386_low_stopped_data_address (&proc->private->arch_private->debug_reg_state,
+ &addr))
+ return addr;
+ return 0; /* ??? fatal? */
+}
+\f
+/* Called when a new process is created. */
+
+static struct arch_process_info *
+x86_linux_new_process (void)
+{
+ struct arch_process_info *info = xcalloc (1, sizeof (*info));
+
+ i386_low_init_dregs (&info->debug_reg_state);
+
+ return info;
+}
+
+/* Called when a new thread is detected. */
+
+static struct arch_lwp_info *
+x86_linux_new_thread (void)
+{
+ struct arch_lwp_info *info = xcalloc (1, sizeof (*info));
+
+ info->debug_registers_changed = 1;
+
+ return info;
+}
+
+/* Called when resuming a thread.
+ If the debug regs have changed, update the thread's copies. */
+
+static void
+x86_linux_prepare_to_resume (struct lwp_info *lwp)
+{
+ if (lwp->arch_private->debug_registers_changed)
+ {
+ int i;
+ ptid_t ptid = ptid_of (lwp);
+ int pid = ptid_get_pid (ptid);
+ struct process_info *proc = find_process_pid (pid);
+ struct i386_debug_reg_state *state = &proc->private->arch_private->debug_reg_state;
+
+ for (i = DR_FIRSTADDR; i <= DR_LASTADDR; i++)
+ x86_linux_dr_set (ptid, i, state->dr_mirror[i]);
+
+ x86_linux_dr_set (ptid, DR_CONTROL, state->dr_control_mirror);
+
+ lwp->arch_private->debug_registers_changed = 0;
+ }
+}
+\f
/* When GDBSERVER is built as a 64-bit application on linux, the
PTRACE_GETSIGINFO data is always presented in 64-bit layout. Since
debugging a 32-bit inferior with a 64-bit GDBSERVER should look the same
@@ -630,10 +817,10 @@ struct linux_target_ops the_low_target =
NULL,
1,
x86_breakpoint_at,
- NULL,
- NULL,
- NULL,
- NULL,
+ x86_insert_watchpoint,
+ x86_remove_watchpoint,
+ x86_stopped_by_watchpoint,
+ x86_stopped_data_address,
/* collect_ptrace_register/supply_ptrace_register are not needed in the
native i386 case (no registers smaller than an xfer unit), and are not
used in the biarch case (HAVE_LINUX_USRREGS is not defined). */
@@ -641,4 +828,7 @@ struct linux_target_ops the_low_target =
NULL,
/* need to fix up i386 siginfo if host is amd64 */
x86_siginfo_fixup,
+ x86_linux_new_process,
+ x86_linux_new_thread,
+ x86_linux_prepare_to_resume
};
Index: server.c
===================================================================
RCS file: /cvs/src/src/gdb/gdbserver/server.c,v
retrieving revision 1.98
diff -u -p -r1.98 server.c
--- server.c 19 Jun 2009 13:35:35 -0000 1.98
+++ server.c 23 Jun 2009 06:35:45 -0000
@@ -51,6 +51,9 @@ static char **program_argv, **wrapper_ar
was originally used to debug LinuxThreads support. */
int debug_threads;
+/* Enable debugging of h/w breakpoint/watchpoint support. */
+int debug_hw_points;
+
int pass_signals[TARGET_SIGNAL_LAST];
jmp_buf toplevel;
@@ -495,6 +498,8 @@ monitor_show_help (void)
monitor_output ("The following monitor commands are supported:\n");
monitor_output (" set debug <0|1>\n");
monitor_output (" Enable general debugging messages\n");
+ monitor_output (" set debug-hw-points <0|1>\n");
+ monitor_output (" Enable h/w breakpoint/watchpoint debugging messages\n");
monitor_output (" set remote-debug <0|1>\n");
monitor_output (" Enable remote protocol debugging messages\n");
monitor_output (" exit\n");
@@ -1216,6 +1221,16 @@ handle_query (char *own_buf, int packet_
debug_threads = 0;
monitor_output ("Debug output disabled.\n");
}
+ else if (strcmp (mon, "set debug-hw-points 1") == 0)
+ {
+ debug_hw_points = 1;
+ monitor_output ("H/W point debugging output enabled.\n");
+ }
+ else if (strcmp (mon, "set debug-hw-points 0") == 0)
+ {
+ debug_hw_points = 0;
+ monitor_output ("H/W point debugging output disabled.\n");
+ }
else if (strcmp (mon, "set remote-debug 1") == 0)
{
remote_debug = 1;
Index: server.h
===================================================================
RCS file: /cvs/src/src/gdb/gdbserver/server.h,v
retrieving revision 1.58
diff -u -p -r1.58 server.h
--- server.h 24 May 2009 21:06:53 -0000 1.58
+++ server.h 23 Jun 2009 06:35:45 -0000
@@ -271,6 +271,7 @@ extern ptid_t step_thread;
extern int server_waiting;
extern int debug_threads;
+extern int debug_hw_points;
extern int pass_signals[];
extern jmp_buf toplevel;
@@ -407,6 +408,7 @@ void perror_with_name (const char *strin
void error (const char *string,...) ATTR_NORETURN ATTR_FORMAT (printf, 1, 2);
void fatal (const char *string,...) ATTR_NORETURN ATTR_FORMAT (printf, 1, 2);
void warning (const char *string,...) ATTR_FORMAT (printf, 1, 2);
+char *paddr (CORE_ADDR addr);
/* Maximum number of bytes to read/write at once. The value here
is chosen to fill up a packet (the headers account for the 32). */
Index: utils.c
===================================================================
RCS file: /cvs/src/src/gdb/gdbserver/utils.c,v
retrieving revision 1.18
diff -u -p -r1.18 utils.c
--- utils.c 19 Jan 2009 00:16:46 -0000 1.18
+++ utils.c 23 Jun 2009 06:35:45 -0000
@@ -170,3 +170,37 @@ warning (const char *string,...)
fprintf (stderr, "\n");
va_end (args);
}
+
+/* Temporary storage using circular buffer. */
+#define NUMCELLS 4
+#define CELLSIZE 50
+static char *
+get_cell (void)
+{
+ static char buf[NUMCELLS][CELLSIZE];
+ static int cell = 0;
+ if (++cell >= NUMCELLS)
+ cell = 0;
+ return buf[cell];
+}
+
+static int
+xsnprintf (char *str, size_t size, const char *format, ...)
+{
+ va_list args;
+ int ret;
+
+ va_start (args, format);
+ ret = vsnprintf (str, size, format, args);
+ va_end (args);
+
+ return ret;
+}
+
+char *
+paddr (CORE_ADDR addr)
+{
+ char *str = get_cell ();
+ xsnprintf (str, CELLSIZE, "%lx", (long) addr);
+ return str;
+}
Index: win32-arm-low.c
===================================================================
RCS file: /cvs/src/src/gdb/gdbserver/win32-arm-low.c,v
retrieving revision 1.8
diff -u -p -r1.8 win32-arm-low.c
--- win32-arm-low.c 3 Jan 2009 05:57:57 -0000 1.8
+++ win32-arm-low.c 23 Jun 2009 06:35:45 -0000
@@ -122,4 +122,9 @@ struct win32_target_ops the_low_target =
NULL, /* single_step */
(const unsigned char *) &arm_wince_breakpoint,
arm_wince_breakpoint_len,
+ /* Watchpoint related functions. See target.h for comments. */
+ NULL, /* insert_watchpoint */
+ NULL, /* remove_watchpoint */
+ NULL, /* stopped_by_watchpoint */
+ NULL /* stopped_data_address */
};
Index: win32-i386-low.c
===================================================================
RCS file: /cvs/src/src/gdb/gdbserver/win32-i386-low.c,v
retrieving revision 1.14
diff -u -p -r1.14 win32-i386-low.c
--- win32-i386-low.c 3 Jan 2009 05:57:57 -0000 1.14
+++ win32-i386-low.c 23 Jun 2009 06:35:45 -0000
@@ -17,6 +17,7 @@
#include "server.h"
#include "win32-low.h"
+#include "i386-low.h"
#define FCS_REGNUM 27
#define FOP_REGNUM 31
@@ -26,15 +27,83 @@
/* Defined in auto-generated file reg-i386.c. */
void init_registers_i386 (void);
-static unsigned dr[8];
+static struct i386_debug_reg_state debug_reg_state;
static int debug_registers_changed = 0;
static int debug_registers_used = 0;
+/* Update the inferior's debug register REGNUM from STATE. */
+
+void
+i386_dr_low_set_addr (const struct i386_debug_reg_state *state, int regnum)
+{
+ if (! (regnum >= 0 && regnum <= DR_LASTADDR - DR_FIRSTADDR))
+ fatal ("Invalid debug register %d", regnum);
+
+ /* debug_reg_state.dr_mirror is already set.
+ Just notify i386_set_thread_context, i386_thread_added
+ that the registers need to be updated. */
+ debug_registers_changed = 1;
+ debug_registers_used = 1;
+}
+
+/* Update the inferior's DR7 debug control register from STATE. */
+
+void
+i386_dr_low_set_control (const struct i386_debug_reg_state *state)
+{
+ /* debug_reg_state.dr_control_mirror is already set.
+ Just notify i386_set_thread_context, i386_thread_added
+ that the registers need to be updated. */
+ debug_registers_changed = 1;
+ debug_registers_used = 1;
+}
+
+/* Get the value of the DR6 debug status register from the inferior
+ and record it in STATE. */
+
+void
+i386_dr_low_get_status (struct i386_debug_reg_state *state)
+{
+ /* We don't need to do anything here, the last call to thread_rec for
+ current_event.dwThreadId id has already set it. */
+}
+
+/* Watchpoint support. */
+
+static int
+i386_insert_watchpoint (char type, CORE_ADDR addr, int len)
+{
+ return i386_low_insert_watchpoint (&debug_reg_state,
+ type, addr, len);
+}
+
+static int
+i386_remove_watchpoint (char type, CORE_ADDR addr, int len)
+{
+ return i386_low_remove_watchpoint (&debug_reg_state,
+ type, addr, len);
+}
+
+static int
+i386_stopped_by_watchpoint (void)
+{
+ return i386_low_stopped_by_watchpoint (&debug_reg_state);
+}
+
+static CORE_ADDR
+i386_stopped_data_address (void)
+{
+ CORE_ADDR addr;
+ if (i386_low_stopped_data_address (&debug_reg_state, &addr))
+ return addr;
+ return 0; /* ??? fatal? */
+}
+
static void
i386_initial_stuff (void)
{
- memset (&dr, 0, sizeof (dr));
+ i386_low_init_dregs (&debug_reg_state);
debug_registers_changed = 0;
debug_registers_used = 0;
}
@@ -55,12 +124,13 @@ i386_get_thread_context (win32_thread_in
if (th->tid == current_event->dwThreadId)
{
/* Copy dr values from the current thread. */
- dr[0] = th->context.Dr0;
- dr[1] = th->context.Dr1;
- dr[2] = th->context.Dr2;
- dr[3] = th->context.Dr3;
- dr[6] = th->context.Dr6;
- dr[7] = th->context.Dr7;
+ struct i386_debug_reg_state *dr = &debug_reg_state;
+ dr->dr_mirror[0] = th->context.Dr0;
+ dr->dr_mirror[1] = th->context.Dr1;
+ dr->dr_mirror[2] = th->context.Dr2;
+ dr->dr_mirror[3] = th->context.Dr3;
+ dr->dr_status_mirror = th->context.Dr6;
+ dr->dr_control_mirror = th->context.Dr7;
}
}
@@ -69,13 +139,14 @@ i386_set_thread_context (win32_thread_in
{
if (debug_registers_changed)
{
- th->context.Dr0 = dr[0];
- th->context.Dr1 = dr[1];
- th->context.Dr2 = dr[2];
- th->context.Dr3 = dr[3];
- /* th->context.Dr6 = dr[6];
+ struct i386_debug_reg_state *dr = &debug_reg_state;
+ th->context.Dr0 = dr->dr_mirror[0];
+ th->context.Dr1 = dr->dr_mirror[1];
+ th->context.Dr2 = dr->dr_mirror[2];
+ th->context.Dr3 = dr->dr_mirror[3];
+ /* th->context.Dr6 = dr->dr_status_mirror;
FIXME: should we set dr6 also ?? */
- th->context.Dr7 = dr[7];
+ th->context.Dr7 = dr->dr_control_mirror;
}
SetThreadContext (th->h, &th->context);
@@ -87,16 +158,17 @@ i386_thread_added (win32_thread_info *th
/* Set the debug registers for the new thread if they are used. */
if (debug_registers_used)
{
+ struct i386_debug_reg_state *dr = &debug_reg_state;
th->context.ContextFlags = CONTEXT_DEBUG_REGISTERS;
GetThreadContext (th->h, &th->context);
- th->context.Dr0 = dr[0];
- th->context.Dr1 = dr[1];
- th->context.Dr2 = dr[2];
- th->context.Dr3 = dr[3];
- /* th->context.Dr6 = dr[6];
+ th->context.Dr0 = dr->dr_mirror[0];
+ th->context.Dr1 = dr->dr_mirror[1];
+ th->context.Dr2 = dr->dr_mirror[2];
+ th->context.Dr3 = dr->dr_mirror[3];
+ /* th->context.Dr6 = dr->dr_status_mirror;
FIXME: should we set dr6 also ?? */
- th->context.Dr7 = dr[7];
+ th->context.Dr7 = dr->dr_control_mirror;
SetThreadContext (th->h, &th->context);
th->context.ContextFlags = 0;
@@ -205,4 +277,8 @@ struct win32_target_ops the_low_target =
i386_single_step,
NULL, /* breakpoint */
0, /* breakpoint_len */
+ i386_insert_watchpoint,
+ i386_remove_watchpoint,
+ i386_stopped_by_watchpoint,
+ i386_stopped_data_address
};
Index: win32-low.c
===================================================================
RCS file: /cvs/src/src/gdb/gdbserver/win32-low.c,v
retrieving revision 1.36
diff -u -p -r1.36 win32-low.c
--- win32-low.c 22 Jun 2009 19:33:41 -0000 1.36
+++ win32-low.c 23 Jun 2009 06:35:45 -0000
@@ -228,6 +228,48 @@ child_delete_thread (DWORD pid, DWORD ti
delete_thread_info (thread);
}
+/* These watchpoint related wrapper functions simply pass on the function call
+ if the target has registered a corresponding function. */
+
+static int
+win32_insert_watchpoint (char type, CORE_ADDR addr, int len)
+{
+ if (the_low_target.insert_watchpoint != NULL)
+ return the_low_target.insert_watchpoint (type, addr, len);
+ else
+ /* Unsupported (see target.h). */
+ return 1;
+}
+
+static int
+win32_remove_watchpoint (char type, CORE_ADDR addr, int len)
+{
+ if (the_low_target.remove_watchpoint != NULL)
+ return the_low_target.remove_watchpoint (type, addr, len);
+ else
+ /* Unsupported (see target.h). */
+ return 1;
+}
+
+static int
+win32_stopped_by_watchpoint (void)
+{
+ if (the_low_target.stopped_by_watchpoint != NULL)
+ return the_low_target.stopped_by_watchpoint ();
+ else
+ return 0;
+}
+
+static CORE_ADDR
+win32_stopped_data_address (void)
+{
+ if (the_low_target.stopped_data_address != NULL)
+ return the_low_target.stopped_data_address ();
+ else
+ return 0;
+}
+
+
/* Transfer memory from/to the debugged process. */
static int
child_xfer_memory (CORE_ADDR memaddr, char *our, int len,
@@ -1697,10 +1739,10 @@ static struct target_ops win32_target_op
NULL,
win32_request_interrupt,
NULL,
- NULL,
- NULL,
- NULL,
- NULL,
+ win32_insert_watchpoint,
+ win32_remove_watchpoint,
+ win32_stopped_by_watchpoint,
+ win32_stopped_data_address,
NULL,
NULL,
NULL,
Index: win32-low.h
===================================================================
RCS file: /cvs/src/src/gdb/gdbserver/win32-low.h,v
retrieving revision 1.9
diff -u -p -r1.9 win32-low.h
--- win32-low.h 3 Jan 2009 05:57:57 -0000 1.9
+++ win32-low.h 23 Jun 2009 06:35:45 -0000
@@ -70,6 +70,12 @@ struct win32_target_ops
const unsigned char *breakpoint;
int breakpoint_len;
+
+ /* Watchpoint related functions. See target.h for comments. */
+ int (*insert_watchpoint) (char type, CORE_ADDR addr, int len);
+ int (*remove_watchpoint) (char type, CORE_ADDR addr, int len);
+ int (*stopped_by_watchpoint) (void);
+ CORE_ADDR (*stopped_data_address) (void);
};
extern struct win32_target_ops the_low_target;
^ permalink raw reply [flat|nested] 18+ messages in thread
* Re: [RFA] i386/amd64 h/w watchpoints in gdbserver
2009-06-23 7:37 ` Doug Evans
@ 2009-06-29 20:45 ` Pedro Alves
2009-06-30 10:32 ` Doug Evans
0 siblings, 1 reply; 18+ messages in thread
From: Pedro Alves @ 2009-06-29 20:45 UTC (permalink / raw)
To: Doug Evans; +Cc: Pierre Muller, gdb-patches
On Tuesday 23 June 2009 08:37:14, Doug Evans wrote:
> On Sat, Jun 20, 2009 at 4:55 PM, Pedro Alves<pedro@codesourcery.com> wrote:
> > On Tuesday 02 June 2009 16:36:05, Doug Evans wrote:
> >
> > I don't think none of these forward declarations is needed?
>
> ok
> [once upon a time, they were ok. the new rules haven't been locked in
> memory yet]
It's easy --- less redundant code to maintain is good. In this case, in addition
to the unnecessary function prototypes, even those large descriptions were
duplicated.
>
> >> +
> >> +int
> >> +i386_low_stopped_by_watchpoint (struct i386_debug_reg_state *state)
> >> +{
> >> + CORE_ADDR addr = 0;
> >> + /* NOTE: gdb version passes boolean found/not-found result from
> >> + i386_stopped_data_address. */
> >> + addr = i386_low_stopped_data_address (state);
> >> + return (addr != 0);
> >> +}
> >
> > Same as above. You've probably thought about that too...
> >
> >> +
> >> +/* Support for h/w breakpoints.
> >> + This support is not currently used, kept for reference. */
> >
> > Any reason for not using this currently? If there's a good reason,
> > than let's drop it. But I'd prefer to have it working. :-)
>
> deleted.
Now you left me curious as to what was missing.
>
> >> Index: utils.c
> >> ===================================================================
> >
> > +char *
> > +paddr (CORE_ADDR addr)
> >
> > This isn't documented in neither server.h or here?
>
> Just "going with the flow".
The flow says: "look closer and you'll see that all functions
in utils.c have description comments."
>
> > +{
> > + char *str = get_cell ();
> > + xsnprintf (str, CELLSIZE, "%lx", (long) addr);
> >
> > ^^^^
> >
> > Note: this will be wrong on Win64... BTW, Ulrich
> > was removing several of these functions from GDB
> > in the removing-current_gdbarch series. Will this one
> > stay? Might be worth it to use the one that is going
> > to stay in GDB.
>
> I think a higher order bit is that gdb and gdbserver cannot share
> code. Bringing over all the smarts to handle all the different
> portability issues is painful/depressing.
I don't think a Win64 port of gdbserver will take too long
to appear, so I'm sure this will an issue (albeit small, as this is
debug output). Note that casting a pointer to long as never been
garanteed to be portable. With the other point, all I meant
was to look here:
http://sourceware.org/ml/gdb-patches/2009-06/msg00223.html
and notice that paddr is gone, in favor of paddress. So, it seemed
to be that if copying an interface from GDB, might as well copy
the one that is going to stay.
> I went with something
> simple that works for now.
> IWBN if this kind of thing were in, say, libiberty and tools could just use it.
Fine, but this is not really an argument. You'd already brought a bit of
code over from GDB, it's just a matter of bringing in more bits. OTOH, for
gdbserver, it wouldn't probably be a problem to just use %p instead. But
I'm fine with going with cast to long for now. It was a "Note:"
afterall. Someone else will have to worry about it.
>
> >> Index: linux-low.h
> >> ===================================================================
> >> RCS file: /cvs/src/src/gdb/gdbserver/linux-low.h,v
> >> retrieving revision 1.30
> >> diff -u -p -r1.30 linux-low.h
> >> --- linux-low.h 12 May 2009 22:25:00 -0000 1.30
> >> +++ linux-low.h 1 Jun 2009 22:02:43 -0000
> >> @@ -56,8 +56,13 @@ struct process_info_private
> >>
> >> /* Connection to the libthread_db library. */
> >> td_thragent_t *thread_agent;
> >> +
> >> + /* Target-specific additions. */
> >
> > Warning: "Target" overload. We need to get into the habit
> > of not doing this --- it makes refering to these things quite
> > ambiguous. Call it "arch" or something else. There are other
> > similar cases.
>
> I dunno. there's "the_low_target" in linux-low.h
> Perhaps we can migrate away but I don't see the above "infraction" as
> being critical.
Please! Could spare us these extra iterations and go with
"Low-target specific additions" then, or some other 4 or 5
letters adjustment, right? ;-) I wasn't asking for a rewrite.
> >> --- linux-x86-low.c 13 May 2009 19:11:04 -0000 1.2
> >> +++ linux-x86-low.c 1 Jun 2009 22:02:43 -0000
> >
> >> +static unsigned long
> >> +x86_linux_dr_get (ptid_t ptid, int regnum)
> >> +{
> >> + int tid;
> >> + unsigned long value;
> >> +
> >> + tid = TIDGET (ptid);
> >> + if (tid == 0)
> >> + tid = PIDGET (ptid);
> >
> > The tid == 0 case is dead code coming from GDB, isn't it?
> > Likewise in other places.
>
> Perhaps. There's similar code in linux-low.c:same_lwp.
> == 0 code deleted.
Yes, but same_lwp really handles cases where
ptid_get_lwp == 0, due to find_lwp_pid. IIUC, these functions
are always called with a full thread ptid.
> >
> >> +/* Update the inferior's debug register REGNUM from STATE. */
> >> +
> >> +void
> >> +i386_dr_low_set_addr (const struct i386_debug_reg_state *state, int regnum)
> >> +{
> >> + struct inferior_list_entry *lp;
> >> + CORE_ADDR addr;
> >> +
> >> + if (! (regnum >= 0 && regnum <= DR_LASTADDR - DR_FIRSTADDR))
> >> + fatal ("Invalid debug register %d", regnum);
> >> +
> >> + addr = state->dr_mirror[regnum];
> >> +
> >> + /* ??? Will need tweaking for multi-process. */
> >
> > Indeed. Why not just set the debug_registers_changed in lwps
> > of the current process?
>
> Are there any existing examples of this?
> I would have done that had process_info contained the list of its
> threads (it would have been trivially straightforward).
Just match the pid of the current process with the pid of
each thread? linux-low.c does that in several places.
> + return 0; /* ??? fatal? */
This just means not-stopped-by-watchpoint? Certainly not fatal.
> Setting aside breakpoints+watchpoints -> "points",
> http://sourceware.org/ml/gdb-patches/2009-06/msg00594.html
Right. An extra point:
On Tuesday 23 June 2009 08:37:14, Doug Evans wrote:
> + default:
> + error ("Z_packet_to_hw_type: bad watchpoint type %c", type);
This should not call error, but return unsupported.
> how about this?
It looks goodish, but I'd really like to see the points I
raise be addressed, instead of just ignored. It just makes
us waste the (narrow already) review bandwidth...
--
Pedro Alves
^ permalink raw reply [flat|nested] 18+ messages in thread
* Re: [RFA] i386/amd64 h/w watchpoints in gdbserver
2009-06-29 20:45 ` Pedro Alves
@ 2009-06-30 10:32 ` Doug Evans
2009-06-30 10:56 ` Pedro Alves
2009-06-30 15:58 ` Pierre Muller
0 siblings, 2 replies; 18+ messages in thread
From: Doug Evans @ 2009-06-30 10:32 UTC (permalink / raw)
To: Pedro Alves; +Cc: Pierre Muller, gdb-patches
[-- Attachment #1: Type: text/plain, Size: 5199 bytes --]
On Mon, Jun 29, 2009 at 1:46 PM, Pedro Alves<pedro@codesourcery.com> wrote:
>> >> +/* Support for h/w breakpoints.
>> >> + This support is not currently used, kept for reference. */
>> >
>> > Any reason for not using this currently? If there's a good reason,
>> > than let's drop it. But I'd prefer to have it working. :-)
>>
>> deleted.
>
> Now you left me curious as to what was missing.
For reference sake, it was deleted because using it would mean adding
new features to the patch. I wanted to keep the focus on the task at
hand. The additions are for a different feature, and it can come in
a later patch.
>> >> Index: utils.c
>> >> ===================================================================
>> >
>> > +char *
>> > +paddr (CORE_ADDR addr)
>> >
>> > This isn't documented in neither server.h or here?
>>
>> Just "going with the flow".
>
> The flow says: "look closer and you'll see that all functions
> in utils.c have description comments."
It wasn't utils.c that I was referring to. Comments added.
> I don't think a Win64 port of gdbserver will take too long
> to appear, so I'm sure this will an issue (albeit small, as this is
> debug output). Note that casting a pointer to long as never been
> garanteed to be portable. With the other point, all I meant
> was to look here:
>
> http://sourceware.org/ml/gdb-patches/2009-06/msg00223.html
>
> and notice that paddr is gone, in favor of paddress. So, it seemed
> to be that if copying an interface from GDB, might as well copy
> the one that is going to stay.
Righto.
The new paddress in gdb has a gdbarch argument which gdbserver
currently doesn't have.
I elided it. I hope that's ok.
>> I went with something
>> simple that works for now.
>> IWBN if this kind of thing were in, say, libiberty and tools could just use it.
>
> Fine, but this is not really an argument. You'd already brought a bit of
> code over from GDB, it's just a matter of bringing in more bits. OTOH, for
> gdbserver, it wouldn't probably be a problem to just use %p instead. But
> I'm fine with going with cast to long for now. It was a "Note:"
> afterall. Someone else will have to worry about it.
The nice thing about wrapping a particular portability issue in one
place is that, well, it's in one place. :-) There are several places
in gdbserver that currently use (long) for printing CORE_ADDRs.
As far as being a "Note", I wonder if we need a convention for review
comments that are mandatory versus review comments that are just
notes, lest future reviews and responses interpret them wrongly (in
either direction).
>> >> + /* Target-specific additions. */
>> >
>> > Warning: "Target" overload. We need to get into the habit
>> > of not doing this --- it makes refering to these things quite
>> > ambiguous. Call it "arch" or something else. There are other
>> > similar cases.
>>
>> I dunno. there's "the_low_target" in linux-low.h
>> Perhaps we can migrate away but I don't see the above "infraction" as
>> being critical.
>
> Please! Could spare us these extra iterations and go with
> "Low-target specific additions" then, or some other 4 or 5
> letters adjustment, right? ;-) I wasn't asking for a rewrite.
'k. I went with arch-specific.
>> >> + /* ??? Will need tweaking for multi-process. */
>> >
>> > Indeed. Why not just set the debug_registers_changed in lwps
>> > of the current process?
>>
>> Are there any existing examples of this?
>> I would have done that had process_info contained the list of its
>> threads (it would have been trivially straightforward).
>
> Just match the pid of the current process with the pid of
> each thread? linux-low.c does that in several places.
'k.
>> + return 0; /* ??? fatal? */
>
> This just means not-stopped-by-watchpoint? Certainly not fatal.
The context here is that the function isn't called unless
stopped_by_watchpoint has returned true. Thus if stopped_data_address
then can't find the address something is wrong.
I've been thinking that stopped_by_watchpoint and stopped_data_address
should be combined, but it's not clear one would always want that.
> Right. An extra point:
>
> On Tuesday 23 June 2009 08:37:14, Doug Evans wrote:
>> + default:
>> + error ("Z_packet_to_hw_type: bad watchpoint type %c", type);
>
> This should not call error, but return unsupported.
This is in a subroutine of functions defined to only handle
watchpoints. "Not supported" is handled at a higher level. I changed
"error" to "fatal" to make this more clear.
>> how about this?
>
> It looks goodish, but I'd really like to see the points I
> raise be addressed, instead of just ignored. It just makes
> us waste the (narrow already) review bandwidth...
I disagree with the categorization of having ignored those comments.
[Plus I did apply roughly 15 of 19 comments without question. 1/2 :-)]
But no worries.
Humble apologies, and noted for future reference.
Pierre, nothing much has changed win32-wise except some functions got renamed.
I don't know if you want to first give this a spin again or not.
[-- Attachment #2: gdb-090630-gdbserver-hw-wp-5.patch.txt --]
[-- Type: text/plain, Size: 53012 bytes --]
2009-06-30 Doug Evans <dje@google.com>
Pierre Muller <muller@ics.u-strasbg.fr>
Add h/w watchpoint support to x86-linux, win32-i386.
* Makefile.in (SFILES): Add i386-low.c
(i386_low_h): Define.
(i386-low.o): Add dependencies.
(linux-x86-low.o): Add i386-low.h dependency.
(win32-i386-low.o): Ditto.
* i386-low.c: New file.
* i386-low.h: New file.
* configure.srv (i[34567]86-*-cygwin*): Add i386-low.o to srv_tgtobj.
(i[34567]86-*-linux*, i[34567]86-*-mingw*, x86_64-*-linux*): Ditto.
* linux-low.c (linux_add_process): Initialize arch_private.
(linux_remove_process): Free arch_private.
(add_lwp): Initialize arch_private.
(delete_lwp): Free arch_private.
(linux_resume_one_lwp): Call the_low_target.prepare_to_resume if
provided.
* linux-low.h (process_info_private): New member arch_private.
(lwp_info): New member arch_private.
(linux_target_ops): New members new_process, new_thread,
prepare_to_resume.
(ptid_of): New macro.
* linux-x86-low.c: Include stddef.h, i386-low.h.
(arch_process_info): New struct.
(arch_lwp_info): New struct.
(x86_linux_dr_get, x86_linux_dr_set): New functions.
(i386_dr_low_set_addr, i386_dr_low_set_control): New functions.
(i386_dr_low_get_status): New function.
(x86_insert_point, x86_remove_point): New functions.
(x86_stopped_by_watchpoint): New function.
(x86_stopped_data_address): New function.
(x86_linux_new_process, x86_linux_new_thread): New functions.
(x86_linux_prepare_to_resume): New function.
(the_low_target): Add entries for insert_point, remove_point,
stopped_by_watchpoint, stopped_data_address, new_process, new_thread,
prepare_to_resume.
* server.c (debug_hw_points): New global.
(monitor_show_help): Document set debug-hw-points.
(handle_query): Process "set debug-hw-points".
* server.h (debug_hw_points): Declare.
(paddress): Declare.
* utils.c (NUMCELLS, CELLSIZE): New macros.
(get_sell, xsnprintf, paddress): New functions.
* win32-arm-low.c (the_low_target): Add entries for insert_point,
remove_point, stopped_by_watchpoint, stopped_data_address.
* win32-i386-low.c: Include i386-low.h.
(debug_reg_state): Replaces dr.
(i386_dr_low_set_addr, i386_dr_low_set_control): New functions.
(i386_dr_low_get_status): New function.
(i386_insert_point, i386_remove_point): New functions.
(i386_stopped_by_watchpoint): New function.
(i386_stopped_data_address): New function.
(i386_initial_stuff): Update.
(get_thread_context,set_thread_context,i386_thread_added): Update.
(the_low_target): Add entries for insert_point,
remove_point, stopped_by_watchpoint, stopped_data_address.
* win32-low.c (win32_insert_watchpoint): New function.
(win32_remove_watchpoint): New function.
(win32_stopped_by_watchpoint): New function.
(win32_stopped_data_address): New function.
(win32_target_ops): Add entries for insert_watchpoint,
remove_watchpoint, stopped_by_watchpoint, stopped_data_address.
* win32-low.h (win32_target_ops): New members insert_point,
remove_point, stopped_by_watchpoint, stopped_data_address.
Index: Makefile.in
===================================================================
RCS file: /cvs/src/src/gdb/gdbserver/Makefile.in,v
retrieving revision 1.74
diff -u -p -r1.74 Makefile.in
--- Makefile.in 12 May 2009 22:25:00 -0000 1.74
+++ Makefile.in 30 Jun 2009 09:15:58 -0000
@@ -104,7 +104,7 @@ SFILES= $(srcdir)/gdbreplay.c $(srcdir)/
$(srcdir)/thread-db.c $(srcdir)/utils.c \
$(srcdir)/linux-arm-low.c $(srcdir)/linux-cris-low.c \
$(srcdir)/linux-crisv32-low.c \
- $(srcdir)/i387-fp.c \
+ ${srcdir}/i386-low.c $(srcdir)/i387-fp.c \
$(srcdir)/linux-ia64-low.c $(srcdir)/linux-low.c \
$(srcdir)/linux-m32r-low.c \
$(srcdir)/linux-m68k-low.c $(srcdir)/linux-mips-low.c \
@@ -287,6 +287,10 @@ signals.o: ../common/signals.c $(server_
memmem.o: ../gnulib/memmem.c
$(CC) -o memmem.o -c $(CPPFLAGS) $(INTERNAL_CFLAGS) $<
+i386_low_h = $(srcdir)/i386-low.h
+
+i386-low.o: i386-low.c $(i386_low_h) $(server_h) $(target_h)
+
i387-fp.o: i387-fp.c $(server_h)
linux-low.o: linux-low.c $(linux_low_h) $(server_h)
@@ -304,7 +308,7 @@ linux-ppc-low.o: linux-ppc-low.c $(linux
linux-s390-low.o: linux-s390-low.c $(linux_low_h) $(server_h)
linux-sh-low.o: linux-sh-low.c $(linux_low_h) $(server_h)
linux-x86-low.o: linux-x86-low.c $(linux_low_h) $(server_h) \
- $(gdb_proc_service_h)
+ $(gdb_proc_service_h) $(i386_low_h)
linux-xtensa-low.o: linux-xtensa-low.c xtensa-xtregs.c $(linux_low_h) $(server_h)
win32_low_h = $(srcdir)/win32-low.h
@@ -312,7 +316,7 @@ win32_low_h = $(srcdir)/win32-low.h
win32-low.o: win32-low.c $(win32_low_h) $(server_h) $(regdef_h) $(regcache_h)
win32-arm-low.o: win32-arm-low.c $(win32_low_h) $(server_h)
-win32-i386-low.o: win32-i386-low.c $(win32_low_h) $(server_h)
+win32-i386-low.o: win32-i386-low.c $(win32_low_h) $(server_h) $(i386_low_h)
spu-low.o: spu-low.c $(server_h)
Index: configure.srv
===================================================================
RCS file: /cvs/src/src/gdb/gdbserver/configure.srv,v
retrieving revision 1.41
diff -u -p -r1.41 configure.srv
--- configure.srv 12 May 2009 22:25:00 -0000 1.41
+++ configure.srv 30 Jun 2009 09:15:58 -0000
@@ -53,10 +53,10 @@ case "${target}" in
srv_linux_thread_db=yes
;;
i[34567]86-*-cygwin*) srv_regobj=reg-i386.o
- srv_tgtobj="win32-low.o win32-i386-low.o"
+ srv_tgtobj="i386-low.o win32-low.o win32-i386-low.o"
;;
i[34567]86-*-linux*) srv_regobj=reg-i386-linux.o
- srv_tgtobj="linux-low.o linux-x86-low.o i387-fp.o"
+ srv_tgtobj="linux-low.o linux-x86-low.o i386-low.o i387-fp.o"
srv_linux_usrregs=yes
srv_linux_regsets=yes
srv_linux_thread_db=yes
@@ -71,7 +71,7 @@ case "${target}" in
srv_mingwce=yes
;;
i[34567]86-*-mingw*) srv_regobj=reg-i386.o
- srv_tgtobj="win32-low.o win32-i386-low.o"
+ srv_tgtobj="i386-low.o win32-low.o win32-i386-low.o"
srv_mingw=yes
;;
ia64-*-linux*) srv_regobj=reg-ia64.o
@@ -170,7 +170,7 @@ case "${target}" in
srv_tgtobj="spu-low.o"
;;
x86_64-*-linux*) srv_regobj="reg-x86-64-linux.o reg-i386-linux.o"
- srv_tgtobj="linux-low.o linux-x86-low.o i387-fp.o"
+ srv_tgtobj="linux-low.o linux-x86-low.o i386-low.o i387-fp.o"
srv_linux_usrregs=yes # This is for i386 progs.
srv_linux_regsets=yes
srv_linux_thread_db=yes
Index: i386-low.c
===================================================================
RCS file: i386-low.c
diff -N i386-low.c
--- /dev/null 1 Jan 1970 00:00:00 -0000
+++ i386-low.c 30 Jun 2009 09:15:58 -0000
@@ -0,0 +1,577 @@
+/* Debug register code for the i386.
+
+ Copyright (C) 2009
+ Free Software Foundation, Inc.
+
+ This file is part of GDB.
+
+ This program is free software; you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation; either version 3 of the License, or
+ (at your option) any later version.
+
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program. If not, see <http://www.gnu.org/licenses/>. */
+
+#include "server.h"
+#include "target.h"
+#include "i386-low.h"
+
+/* Support for 8-byte wide hw watchpoints. */
+#ifndef TARGET_HAS_DR_LEN_8
+/* NOTE: sizeof (long) == 4 on win64. */
+#define TARGET_HAS_DR_LEN_8 (sizeof (void *) == 8)
+#endif
+
+enum target_hw_bp_type
+ {
+ hw_write = 0, /* Common HW watchpoint */
+ hw_read = 1, /* Read HW watchpoint */
+ hw_access = 2, /* Access HW watchpoint */
+ hw_execute = 3 /* Execute HW breakpoint */
+ };
+
+/* DR7 Debug Control register fields. */
+
+/* How many bits to skip in DR7 to get to R/W and LEN fields. */
+#define DR_CONTROL_SHIFT 16
+/* How many bits in DR7 per R/W and LEN field for each watchpoint. */
+#define DR_CONTROL_SIZE 4
+
+/* Watchpoint/breakpoint read/write fields in DR7. */
+#define DR_RW_EXECUTE (0x0) /* Break on instruction execution. */
+#define DR_RW_WRITE (0x1) /* Break on data writes. */
+#define DR_RW_READ (0x3) /* Break on data reads or writes. */
+
+/* This is here for completeness. No platform supports this
+ functionality yet (as of March 2001). Note that the DE flag in the
+ CR4 register needs to be set to support this. */
+#ifndef DR_RW_IORW
+#define DR_RW_IORW (0x2) /* Break on I/O reads or writes. */
+#endif
+
+/* Watchpoint/breakpoint length fields in DR7. The 2-bit left shift
+ is so we could OR this with the read/write field defined above. */
+#define DR_LEN_1 (0x0 << 2) /* 1-byte region watch or breakpoint. */
+#define DR_LEN_2 (0x1 << 2) /* 2-byte region watch. */
+#define DR_LEN_4 (0x3 << 2) /* 4-byte region watch. */
+#define DR_LEN_8 (0x2 << 2) /* 8-byte region watch (AMD64). */
+
+/* Local and Global Enable flags in DR7.
+
+ When the Local Enable flag is set, the breakpoint/watchpoint is
+ enabled only for the current task; the processor automatically
+ clears this flag on every task switch. When the Global Enable flag
+ is set, the breakpoint/watchpoint is enabled for all tasks; the
+ processor never clears this flag.
+
+ Currently, all watchpoint are locally enabled. If you need to
+ enable them globally, read the comment which pertains to this in
+ i386_insert_aligned_watchpoint below. */
+#define DR_LOCAL_ENABLE_SHIFT 0 /* Extra shift to the local enable bit. */
+#define DR_GLOBAL_ENABLE_SHIFT 1 /* Extra shift to the global enable bit. */
+#define DR_ENABLE_SIZE 2 /* Two enable bits per debug register. */
+
+/* Local and global exact breakpoint enable flags (a.k.a. slowdown
+ flags). These are only required on i386, to allow detection of the
+ exact instruction which caused a watchpoint to break; i486 and
+ later processors do that automatically. We set these flags for
+ backwards compatibility. */
+#define DR_LOCAL_SLOWDOWN (0x100)
+#define DR_GLOBAL_SLOWDOWN (0x200)
+
+/* Fields reserved by Intel. This includes the GD (General Detect
+ Enable) flag, which causes a debug exception to be generated when a
+ MOV instruction accesses one of the debug registers.
+
+ FIXME: My Intel manual says we should use 0xF800, not 0xFC00. */
+#define DR_CONTROL_RESERVED (0xFC00)
+
+/* Auxiliary helper macros. */
+
+/* A value that masks all fields in DR7 that are reserved by Intel. */
+#define I386_DR_CONTROL_MASK (~DR_CONTROL_RESERVED)
+
+/* The I'th debug register is vacant if its Local and Global Enable
+ bits are reset in the Debug Control register. */
+#define I386_DR_VACANT(state, i) \
+ (((state)->dr_control_mirror & (3 << (DR_ENABLE_SIZE * (i)))) == 0)
+
+/* Locally enable the break/watchpoint in the I'th debug register. */
+#define I386_DR_LOCAL_ENABLE(state, i) \
+ do { \
+ (state)->dr_control_mirror |= \
+ (1 << (DR_LOCAL_ENABLE_SHIFT + DR_ENABLE_SIZE * (i))); \
+ } while (0)
+
+/* Globally enable the break/watchpoint in the I'th debug register. */
+#define I386_DR_GLOBAL_ENABLE(state, i) \
+ do { \
+ (state)->dr_control_mirror |= \
+ (1 << (DR_GLOBAL_ENABLE_SHIFT + DR_ENABLE_SIZE * (i))); \
+ } while (0)
+
+/* Disable the break/watchpoint in the I'th debug register. */
+#define I386_DR_DISABLE(state, i) \
+ do { \
+ (state)->dr_control_mirror &= \
+ ~(3 << (DR_ENABLE_SIZE * (i))); \
+ } while (0)
+
+/* Set in DR7 the RW and LEN fields for the I'th debug register. */
+#define I386_DR_SET_RW_LEN(state, i,rwlen) \
+ do { \
+ (state)->dr_control_mirror &= \
+ ~(0x0f << (DR_CONTROL_SHIFT + DR_CONTROL_SIZE * (i))); \
+ (state)->dr_control_mirror |= \
+ ((rwlen) << (DR_CONTROL_SHIFT + DR_CONTROL_SIZE * (i))); \
+ } while (0)
+
+/* Get from DR7 the RW and LEN fields for the I'th debug register. */
+#define I386_DR_GET_RW_LEN(state, i) \
+ (((state)->dr_control_mirror \
+ >> (DR_CONTROL_SHIFT + DR_CONTROL_SIZE * (i))) & 0x0f)
+
+/* Did the watchpoint whose address is in the I'th register break? */
+#define I386_DR_WATCH_HIT(state,i) ((state)->dr_status_mirror & (1 << (i)))
+
+/* A macro to loop over all debug registers. */
+#define ALL_DEBUG_REGISTERS(i) for (i = 0; i < DR_NADDR; i++)
+
+/* Types of operations supported by i386_handle_nonaligned_watchpoint. */
+typedef enum { WP_INSERT, WP_REMOVE, WP_COUNT } i386_wp_op_t;
+\f
+/* Implementation. */
+
+/* Clear the reference counts and forget everything we knew about the
+ debug registers. */
+
+void
+i386_low_init_dregs (struct i386_debug_reg_state *state)
+{
+ int i;
+
+ ALL_DEBUG_REGISTERS (i)
+ {
+ state->dr_mirror[i] = 0;
+ state->dr_ref_count[i] = 0;
+ }
+ state->dr_control_mirror = 0;
+ state->dr_status_mirror = 0;
+}
+
+/* Print the values of the mirrored debug registers. This is enabled via
+ the "set debug-hw-points 1" monitor command. */
+
+static void
+i386_show_dr (struct i386_debug_reg_state *state,
+ const char *func, CORE_ADDR addr,
+ int len, enum target_hw_bp_type type)
+{
+ int i;
+
+ fprintf (stderr, "%s", func);
+ if (addr || len)
+ fprintf (stderr, " (addr=%lx, len=%d, type=%s)",
+ (unsigned long) addr, len,
+ type == hw_write ? "data-write"
+ : (type == hw_read ? "data-read"
+ : (type == hw_access ? "data-read/write"
+ : (type == hw_execute ? "instruction-execute"
+ /* FIXME: if/when I/O read/write
+ watchpoints are supported, add them
+ here. */
+ : "??unknown??"))));
+ fprintf (stderr, ":\n");
+ fprintf (stderr, "\tCONTROL (DR7): %08x STATUS (DR6): %08x\n",
+ state->dr_control_mirror, state->dr_status_mirror);
+ ALL_DEBUG_REGISTERS (i)
+ {
+ fprintf (stderr, "\
+\tDR%d: addr=0x%s, ref.count=%d DR%d: addr=0x%s, ref.count=%d\n",
+ i, paddress (state->dr_mirror[i]),
+ state->dr_ref_count[i],
+ i + 1, paddress (state->dr_mirror[i + 1]),
+ state->dr_ref_count[i + 1]);
+ i++;
+ }
+}
+
+/* Return the value of a 4-bit field for DR7 suitable for watching a
+ region of LEN bytes for accesses of type TYPE. LEN is assumed to
+ have the value of 1, 2, or 4. */
+
+static unsigned
+i386_length_and_rw_bits (int len, enum target_hw_bp_type type)
+{
+ unsigned rw;
+
+ switch (type)
+ {
+ case hw_execute:
+ rw = DR_RW_EXECUTE;
+ break;
+ case hw_write:
+ rw = DR_RW_WRITE;
+ break;
+ case hw_read:
+ /* The i386 doesn't support data-read watchpoints. */
+ case hw_access:
+ rw = DR_RW_READ;
+ break;
+#if 0
+ /* Not yet supported. */
+ case hw_io_access:
+ rw = DR_RW_IORW;
+ break;
+#endif
+ default:
+ error ("\
+Invalid hardware breakpoint type %d in i386_length_and_rw_bits.\n",
+ (int) type);
+ }
+
+ switch (len)
+ {
+ case 1:
+ return (DR_LEN_1 | rw);
+ case 2:
+ return (DR_LEN_2 | rw);
+ case 4:
+ return (DR_LEN_4 | rw);
+ case 8:
+ if (TARGET_HAS_DR_LEN_8)
+ return (DR_LEN_8 | rw);
+ default:
+ error ("\
+Invalid hardware breakpoint length %d in i386_length_and_rw_bits.\n", len);
+ }
+}
+
+/* Insert a watchpoint at address ADDR, which is assumed to be aligned
+ according to the length of the region to watch. LEN_RW_BITS is the
+ value of the bits from DR7 which describes the length and access
+ type of the region to be watched by this watchpoint. Return 0 on
+ success, -1 on failure. */
+
+static int
+i386_insert_aligned_watchpoint (struct i386_debug_reg_state *state,
+ CORE_ADDR addr, unsigned len_rw_bits)
+{
+ int i;
+
+ /* First, look for an occupied debug register with the same address
+ and the same RW and LEN definitions. If we find one, we can
+ reuse it for this watchpoint as well (and save a register). */
+ ALL_DEBUG_REGISTERS (i)
+ {
+ if (!I386_DR_VACANT (state, i)
+ && state->dr_mirror[i] == addr
+ && I386_DR_GET_RW_LEN (state, i) == len_rw_bits)
+ {
+ state->dr_ref_count[i]++;
+ return 0;
+ }
+ }
+
+ /* Next, look for a vacant debug register. */
+ ALL_DEBUG_REGISTERS (i)
+ {
+ if (I386_DR_VACANT (state, i))
+ break;
+ }
+
+ /* No more debug registers! */
+ if (i >= DR_NADDR)
+ return -1;
+
+ /* Now set up the register I to watch our region. */
+
+ /* Record the info in our local mirrored array. */
+ state->dr_mirror[i] = addr;
+ state->dr_ref_count[i] = 1;
+ I386_DR_SET_RW_LEN (state, i, len_rw_bits);
+ /* Note: we only enable the watchpoint locally, i.e. in the current
+ task. Currently, no i386 target allows or supports global
+ watchpoints; however, if any target would want that in the
+ future, GDB should probably provide a command to control whether
+ to enable watchpoints globally or locally, and the code below
+ should use global or local enable and slow-down flags as
+ appropriate. */
+ I386_DR_LOCAL_ENABLE (state, i);
+ state->dr_control_mirror |= DR_LOCAL_SLOWDOWN;
+ state->dr_control_mirror &= I386_DR_CONTROL_MASK;
+
+ /* Finally, actually pass the info to the inferior. */
+ i386_dr_low_set_addr (state, i);
+ i386_dr_low_set_control (state);
+
+ return 0;
+}
+
+/* Remove a watchpoint at address ADDR, which is assumed to be aligned
+ according to the length of the region to watch. LEN_RW_BITS is the
+ value of the bits from DR7 which describes the length and access
+ type of the region watched by this watchpoint. Return 0 on
+ success, -1 on failure. */
+
+static int
+i386_remove_aligned_watchpoint (struct i386_debug_reg_state *state,
+ CORE_ADDR addr, unsigned len_rw_bits)
+{
+ int i, retval = -1;
+
+ ALL_DEBUG_REGISTERS (i)
+ {
+ if (!I386_DR_VACANT (state, i)
+ && state->dr_mirror[i] == addr
+ && I386_DR_GET_RW_LEN (state, i) == len_rw_bits)
+ {
+ if (--state->dr_ref_count[i] == 0) /* No longer in use? */
+ {
+ /* Reset our mirror. */
+ state->dr_mirror[i] = 0;
+ I386_DR_DISABLE (state, i);
+ /* Reset it in the inferior. */
+ i386_dr_low_set_control (state);
+ i386_dr_low_set_addr (state, i);
+ }
+ retval = 0;
+ }
+ }
+
+ return retval;
+}
+
+/* Insert or remove a (possibly non-aligned) watchpoint, or count the
+ number of debug registers required to watch a region at address
+ ADDR whose length is LEN for accesses of type TYPE. Return 0 on
+ successful insertion or removal, a positive number when queried
+ about the number of registers, or -1 on failure. If WHAT is not a
+ valid value, bombs through internal_error. */
+
+static int
+i386_handle_nonaligned_watchpoint (struct i386_debug_reg_state *state,
+ i386_wp_op_t what, CORE_ADDR addr, int len,
+ enum target_hw_bp_type type)
+{
+ int retval = 0, status = 0;
+ int max_wp_len = TARGET_HAS_DR_LEN_8 ? 8 : 4;
+
+ static const int size_try_array[8][8] =
+ {
+ {1, 1, 1, 1, 1, 1, 1, 1}, /* Trying size one. */
+ {2, 1, 2, 1, 2, 1, 2, 1}, /* Trying size two. */
+ {2, 1, 2, 1, 2, 1, 2, 1}, /* Trying size three. */
+ {4, 1, 2, 1, 4, 1, 2, 1}, /* Trying size four. */
+ {4, 1, 2, 1, 4, 1, 2, 1}, /* Trying size five. */
+ {4, 1, 2, 1, 4, 1, 2, 1}, /* Trying size six. */
+ {4, 1, 2, 1, 4, 1, 2, 1}, /* Trying size seven. */
+ {8, 1, 2, 1, 4, 1, 2, 1}, /* Trying size eight. */
+ };
+
+ while (len > 0)
+ {
+ int align = addr % max_wp_len;
+ /* Four (eight on AMD64) is the maximum length a debug register
+ can watch. */
+ int try = (len > max_wp_len ? (max_wp_len - 1) : len - 1);
+ int size = size_try_array[try][align];
+
+ if (what == WP_COUNT)
+ {
+ /* size_try_array[] is defined such that each iteration
+ through the loop is guaranteed to produce an address and a
+ size that can be watched with a single debug register.
+ Thus, for counting the registers required to watch a
+ region, we simply need to increment the count on each
+ iteration. */
+ retval++;
+ }
+ else
+ {
+ unsigned len_rw = i386_length_and_rw_bits (size, type);
+
+ if (what == WP_INSERT)
+ status = i386_insert_aligned_watchpoint (state, addr, len_rw);
+ else if (what == WP_REMOVE)
+ status = i386_remove_aligned_watchpoint (state, addr, len_rw);
+ else
+ fatal ("\
+Invalid value %d of operation in i386_handle_nonaligned_watchpoint.\n",
+ (int) what);
+
+ /* We keep the loop going even after a failure, because some
+ of the other aligned watchpoints might still succeed
+ (e.g. if they watch addresses that are already watched,
+ in which case we just increment the reference counts of
+ occupied debug registers). If we break out of the loop
+ too early, we could cause those addresses watched by
+ other watchpoints to be disabled when breakpoint.c reacts
+ to our failure to insert this watchpoint and tries to
+ remove it. */
+ if (status)
+ retval = status;
+ }
+
+ addr += size;
+ len -= size;
+ }
+
+ return retval;
+}
+
+#define Z_PACKET_WRITE_WP '2'
+#define Z_PACKET_READ_WP '3'
+#define Z_PACKET_ACCESS_WP '4'
+
+/* Map the protocol watchpoint type TYPE to enum target_hw_bp_type. */
+
+static enum target_hw_bp_type
+Z_packet_to_hw_type (char type)
+{
+ switch (type)
+ {
+ case Z_PACKET_WRITE_WP:
+ return hw_write;
+ case Z_PACKET_READ_WP:
+ return hw_read;
+ case Z_PACKET_ACCESS_WP:
+ return hw_access;
+ default:
+ fatal ("Z_packet_to_hw_type: bad watchpoint type %c", type);
+ }
+}
+
+/* Insert a watchpoint to watch a memory region which starts at
+ address ADDR and whose length is LEN bytes. Watch memory accesses
+ of the type TYPE_FROM_PACKET. Return 0 on success, -1 on failure. */
+
+int
+i386_low_insert_watchpoint (struct i386_debug_reg_state *state,
+ char type_from_packet, CORE_ADDR addr, int len)
+{
+ int retval;
+ enum target_hw_bp_type type = Z_packet_to_hw_type (type_from_packet);
+
+ if (((len != 1 && len != 2 && len != 4)
+ && !(TARGET_HAS_DR_LEN_8 && len == 8))
+ || addr % len != 0)
+ {
+ retval = i386_handle_nonaligned_watchpoint (state, WP_INSERT,
+ addr, len, type);
+ }
+ else
+ {
+ unsigned len_rw = i386_length_and_rw_bits (len, type);
+
+ retval = i386_insert_aligned_watchpoint (state, addr, len_rw);
+ }
+
+ if (debug_hw_points)
+ i386_show_dr (state, "insert_watchpoint", addr, len, type);
+
+ return retval;
+}
+
+/* Remove a watchpoint that watched the memory region which starts at
+ address ADDR, whose length is LEN bytes, and for accesses of the
+ type TYPE_FROM_PACKET. Return 0 on success, -1 on failure. */
+
+int
+i386_low_remove_watchpoint (struct i386_debug_reg_state *state,
+ char type_from_packet, CORE_ADDR addr, int len)
+{
+ int retval;
+ enum target_hw_bp_type type = Z_packet_to_hw_type (type_from_packet);
+
+ if (((len != 1 && len != 2 && len != 4)
+ && !(TARGET_HAS_DR_LEN_8 && len == 8))
+ || addr % len != 0)
+ {
+ retval = i386_handle_nonaligned_watchpoint (state, WP_REMOVE,
+ addr, len, type);
+ }
+ else
+ {
+ unsigned len_rw = i386_length_and_rw_bits (len, type);
+
+ retval = i386_remove_aligned_watchpoint (state, addr, len_rw);
+ }
+
+ if (debug_hw_points)
+ i386_show_dr (state, "remove_watchpoint", addr, len, type);
+
+ return retval;
+}
+
+/* Return non-zero if we can watch a memory region that starts at
+ address ADDR and whose length is LEN bytes. */
+
+int
+i386_low_region_ok_for_watchpoint (struct i386_debug_reg_state *state,
+ CORE_ADDR addr, int len)
+{
+ int nregs;
+
+ /* Compute how many aligned watchpoints we would need to cover this
+ region. */
+ nregs = i386_handle_nonaligned_watchpoint (state, WP_COUNT,
+ addr, len, hw_write);
+ return nregs <= DR_NADDR ? 1 : 0;
+}
+
+/* If the inferior has some break/watchpoint that triggered, set the
+ address associated with that break/watchpoint and return true.
+ Otherwise, return false. */
+
+int
+i386_low_stopped_data_address (struct i386_debug_reg_state *state,
+ CORE_ADDR *addr_p)
+{
+ CORE_ADDR addr = 0;
+ int i;
+ int rc = 0;
+
+ /* Get dr_status_mirror for use by I386_DR_WATCH_HIT. */
+ i386_dr_low_get_status (state);
+
+ ALL_DEBUG_REGISTERS (i)
+ {
+ if (I386_DR_WATCH_HIT (state, i)
+ /* This second condition makes sure DRi is set up for a data
+ watchpoint, not a hardware breakpoint. The reason is
+ that GDB doesn't call the target_stopped_data_address
+ method except for data watchpoints. In other words, I'm
+ being paranoiac. */
+ && I386_DR_GET_RW_LEN (state, i) != 0)
+ {
+ addr = state->dr_mirror[i];
+ rc = 1;
+ if (debug_hw_points)
+ i386_show_dr (state, "watchpoint_hit", addr, -1, hw_write);
+ }
+ }
+
+ if (debug_hw_points && addr == 0)
+ i386_show_dr (state, "stopped_data_addr", 0, 0, hw_write);
+
+ if (rc)
+ *addr_p = addr;
+ return rc;
+}
+
+/* Return true if the inferior has some watchpoint that triggered.
+ Otherwise return false. */
+
+int
+i386_low_stopped_by_watchpoint (struct i386_debug_reg_state *state)
+{
+ CORE_ADDR addr = 0;
+ return i386_low_stopped_data_address (state, &addr);
+}
Index: i386-low.h
===================================================================
RCS file: i386-low.h
diff -N i386-low.h
--- /dev/null 1 Jan 1970 00:00:00 -0000
+++ i386-low.h 30 Jun 2009 09:15:58 -0000
@@ -0,0 +1,109 @@
+/* Misc. low level support for i386.
+
+ Copyright (C) 2009
+ Free Software Foundation, Inc.
+
+ This file is part of GDB.
+
+ This program is free software; you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation; either version 3 of the License, or
+ (at your option) any later version.
+
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program. If not, see <http://www.gnu.org/licenses/>. */
+
+/* Support for hardware watchpoints and breakpoints using the i386
+ debug registers.
+
+ This provides several functions for inserting and removing
+ hardware-assisted breakpoints and watchpoints, testing if one or
+ more of the watchpoints triggered and at what address, checking
+ whether a given region can be watched, etc.
+
+ The functions below implement debug registers sharing by reference
+ counts, and allow to watch regions up to 16 bytes long
+ (32 bytes on 64 bit hosts). */
+
+
+/* Debug registers' indices. */
+#define DR_FIRSTADDR 0
+#define DR_LASTADDR 3
+#define DR_NADDR 4 /* The number of debug address registers. */
+#define DR_STATUS 6
+#define DR_CONTROL 7
+
+/* Global state needed to track h/w watchpoints. */
+
+struct i386_debug_reg_state
+{
+ /* Mirror the inferior's DRi registers. We keep the status and
+ control registers separated because they don't hold addresses. */
+ CORE_ADDR dr_mirror[DR_NADDR];
+ unsigned dr_status_mirror, dr_control_mirror;
+
+ /* Reference counts for each debug register. */
+ int dr_ref_count[DR_NADDR];
+};
+
+/* Initialize STATE. */
+extern void i386_low_init_dregs (struct i386_debug_reg_state *state);
+
+/* Insert a watchpoint to watch a memory region which starts at
+ address ADDR and whose length is LEN bytes. Watch memory accesses
+ of the type TYPE_FROM_PACKET. Return 0 on success, -1 on failure. */
+extern int i386_low_insert_watchpoint (struct i386_debug_reg_state *state,
+ char type_from_packet, CORE_ADDR addr,
+ int len);
+
+/* Remove a watchpoint that watched the memory region which starts at
+ address ADDR, whose length is LEN bytes, and for accesses of the
+ type TYPE_FROM_PACKET. Return 0 on success, -1 on failure. */
+extern int i386_low_remove_watchpoint (struct i386_debug_reg_state *state,
+ char type_from_packet, CORE_ADDR addr,
+ int len);
+
+/* Return non-zero if we can watch a memory region that starts at
+ address ADDR and whose length is LEN bytes. */
+extern int i386_low_region_ok_for_watchpoint (struct i386_debug_reg_state *state,
+ CORE_ADDR addr, int len);
+
+/* If the inferior has some break/watchpoint that triggered, set the
+ address associated with that break/watchpoint and return true.
+ Otherwise, return false. */
+extern int i386_low_stopped_data_address (struct i386_debug_reg_state *state,
+ CORE_ADDR *addr_p);
+
+/* Return true if the inferior has some watchpoint that triggered.
+ Otherwise return false. */
+extern int i386_low_stopped_by_watchpoint (struct i386_debug_reg_state *state);
+\f
+/* Each target needs to provide several low-level functions
+ that will be called to insert watchpoints and hardware breakpoints
+ into the inferior, remove them, and check their status. These
+ functions are:
+
+ i386_dr_low_set_control -- set the debug control (DR7)
+ register to a given value
+
+ i386_dr_low_set_addr -- put an address into one debug register
+
+ i386_dr_low_get_status -- return the value of the debug
+ status (DR6) register.
+*/
+
+/* Update the inferior's debug register REGNUM from STATE. */
+extern void i386_dr_low_set_addr (const struct i386_debug_reg_state *state,
+ int regnum);
+
+/* Update the inferior's DR7 debug control register from STATE. */
+extern void i386_dr_low_set_control (const struct i386_debug_reg_state *state);
+
+/* Get the value of the inferior's DR6 debug status register
+ and record it in STATE. */
+extern void i386_dr_low_get_status (struct i386_debug_reg_state *state);
Index: linux-low.c
===================================================================
RCS file: /cvs/src/src/gdb/gdbserver/linux-low.c,v
retrieving revision 1.108
diff -u -p -r1.108 linux-low.c
--- linux-low.c 25 Jun 2009 22:13:53 -0000 1.108
+++ linux-low.c 30 Jun 2009 09:15:58 -0000
@@ -224,6 +224,7 @@ delete_lwp (struct lwp_info *lwp)
{
remove_thread (get_lwp_thread (lwp));
remove_inferior (&all_lwps, &lwp->head);
+ free (lwp->arch_private);
free (lwp);
}
@@ -242,6 +243,9 @@ linux_add_process (int pid, int attached
proc = add_process (pid, attached);
proc->private = xcalloc (1, sizeof (*proc->private));
+ if (the_low_target.new_process != NULL)
+ proc->private->arch_private = the_low_target.new_process ();
+
return proc;
}
@@ -251,6 +255,7 @@ linux_add_process (int pid, int attached
static void
linux_remove_process (struct process_info *process)
{
+ free (process->private->arch_private);
free (process->private);
remove_process (process);
}
@@ -376,6 +381,9 @@ add_lwp (ptid_t ptid)
lwp->head.id = ptid;
+ if (the_low_target.new_thread != NULL)
+ lwp->arch_private = the_low_target.new_thread ();
+
add_inferior_to_list (&all_lwps, &lwp->head);
return lwp;
@@ -466,7 +474,6 @@ linux_attach_lwp_1 (unsigned long lwpid,
new_lwp = (struct lwp_info *) add_lwp (ptid);
add_thread (ptid, new_lwp);
-
/* We need to wait for SIGSTOP before being able to make the next
ptrace call on this LWP. */
new_lwp->must_set_ptrace_flags = 1;
@@ -1740,6 +1747,9 @@ linux_resume_one_lwp (struct lwp_info *l
*p_sig = NULL;
}
+ if (the_low_target.prepare_to_resume != NULL)
+ the_low_target.prepare_to_resume (lwp);
+
regcache_invalidate_one ((struct inferior_list_entry *)
get_lwp_thread (lwp));
errno = 0;
Index: linux-low.h
===================================================================
RCS file: /cvs/src/src/gdb/gdbserver/linux-low.h,v
retrieving revision 1.31
diff -u -p -r1.31 linux-low.h
--- linux-low.h 25 Jun 2009 22:13:53 -0000 1.31
+++ linux-low.h 30 Jun 2009 09:15:58 -0000
@@ -56,8 +56,13 @@ struct process_info_private
/* Connection to the libthread_db library. */
td_thragent_t *thread_agent;
+
+ /* Arch-specific additions. */
+ struct arch_process_info *arch_private;
};
+struct lwp_info;
+
struct linux_target_ops
{
/* Architecture-specific setup. */
@@ -97,10 +102,24 @@ struct linux_target_ops
If DIRECTION is 1, then copy from INF to NATIVE.
If DIRECTION is 0, copy from NATIVE to INF. */
int (*siginfo_fixup) (struct siginfo *native, void *inf, int direction);
+
+ /* Hook to call when a new process is created or attached to.
+ If extra per-process architecture-specific data is needed,
+ allocate it here. */
+ struct arch_process_info * (*new_process) (void);
+
+ /* Hook to call when a new thread is detected.
+ If extra per-thread architecture-specific data is needed,
+ allocate it here. */
+ struct arch_lwp_info * (*new_thread) (void);
+
+ /* Hook to call prior to resuming a thread. */
+ void (*prepare_to_resume) (struct lwp_info *);
};
extern struct linux_target_ops the_low_target;
+#define ptid_of(proc) ((proc)->head.id)
#define pid_of(proc) ptid_get_pid ((proc)->head.id)
#define lwpid_of(proc) ptid_get_lwp ((proc)->head.id)
@@ -173,6 +192,9 @@ struct lwp_info
THREAD_KNOWN is set. */
td_thrhandle_t th;
#endif
+
+ /* Arch-specific additions. */
+ struct arch_lwp_info *arch_private;
};
extern struct inferior_list all_lwps;
Index: linux-x86-low.c
===================================================================
RCS file: /cvs/src/src/gdb/gdbserver/linux-x86-low.c,v
retrieving revision 1.2
diff -u -p -r1.2 linux-x86-low.c
--- linux-x86-low.c 13 May 2009 19:11:04 -0000 1.2
+++ linux-x86-low.c 30 Jun 2009 09:15:58 -0000
@@ -18,10 +18,12 @@
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>. */
+#include <stddef.h>
#include <signal.h>
#include "server.h"
#include "linux-low.h"
#include "i387-fp.h"
+#include "i386-low.h"
#include "gdb_proc_service.h"
@@ -56,6 +58,21 @@ void init_registers_x86_64_linux (void);
#define ARCH_GET_GS 0x1004
#endif
+/* Per-process arch-specific data we want to keep. */
+
+struct arch_process_info
+{
+ struct i386_debug_reg_state debug_reg_state;
+};
+
+/* Per-thread arch-specific data we want to keep. */
+
+struct arch_lwp_info
+{
+ /* Non-zero if our copy differs from what's recorded in the thread. */
+ int debug_registers_changed;
+};
+
#ifdef __x86_64__
/* Mapping between the general-purpose registers in `struct user'
@@ -317,6 +334,198 @@ x86_breakpoint_at (CORE_ADDR pc)
return 0;
}
\f
+/* Support for debug registers. */
+
+static unsigned long
+x86_linux_dr_get (ptid_t ptid, int regnum)
+{
+ int tid;
+ unsigned long value;
+
+ tid = ptid_get_lwp (ptid);
+
+ errno = 0;
+ value = ptrace (PTRACE_PEEKUSER, tid,
+ offsetof (struct user, u_debugreg[regnum]), 0);
+ if (errno != 0)
+ error ("Couldn't read debug register");
+
+ return value;
+}
+
+static void
+x86_linux_dr_set (ptid_t ptid, int regnum, unsigned long value)
+{
+ int tid;
+
+ tid = ptid_get_lwp (ptid);
+
+ errno = 0;
+ ptrace (PTRACE_POKEUSER, tid,
+ offsetof (struct user, u_debugreg[regnum]), value);
+ if (errno != 0)
+ error ("Couldn't write debug register");
+}
+
+/* Update the inferior's debug register REGNUM from STATE. */
+
+void
+i386_dr_low_set_addr (const struct i386_debug_reg_state *state, int regnum)
+{
+ struct inferior_list_entry *lp;
+ CORE_ADDR addr;
+ /* Only need to update the threads of this process. */
+ int pid = pid_of (get_thread_lwp (current_inferior));
+
+ if (! (regnum >= 0 && regnum <= DR_LASTADDR - DR_FIRSTADDR))
+ fatal ("Invalid debug register %d", regnum);
+
+ addr = state->dr_mirror[regnum];
+
+ for (lp = all_lwps.head; lp; lp = lp->next)
+ {
+ struct lwp_info *lwp = (struct lwp_info *) lp;
+
+ /* The actual update is done later, we just mark that the register
+ needs updating. */
+ if (pid_of (lwp) == pid)
+ lwp->arch_private->debug_registers_changed = 1;
+ }
+}
+
+/* Update the inferior's DR7 debug control register from STATE. */
+
+void
+i386_dr_low_set_control (const struct i386_debug_reg_state *state)
+{
+ struct inferior_list_entry *lp;
+ /* Only need to update the threads of this process. */
+ int pid = pid_of (get_thread_lwp (current_inferior));
+
+ for (lp = all_lwps.head; lp; lp = lp->next)
+ {
+ struct lwp_info *lwp = (struct lwp_info *) lp;
+
+ /* The actual update is done later, we just mark that the register
+ needs updating. */
+ if (pid_of (lwp) == pid)
+ lwp->arch_private->debug_registers_changed = 1;
+ }
+}
+
+/* Get the value of the DR6 debug status register from the inferior
+ and record it in STATE. */
+
+void
+i386_dr_low_get_status (struct i386_debug_reg_state *state)
+{
+ struct lwp_info *lwp = get_thread_lwp (current_inferior);
+ ptid_t ptid = ptid_of (lwp);
+
+ state->dr_status_mirror = x86_linux_dr_get (ptid, DR_STATUS);
+}
+\f
+/* Watchpoint support. */
+
+static int
+x86_insert_point (char type, CORE_ADDR addr, int len)
+{
+ struct process_info *proc = current_process ();
+ switch (type)
+ {
+ case '2':
+ case '3':
+ case '4':
+ return i386_low_insert_watchpoint (&proc->private->arch_private->debug_reg_state,
+ type, addr, len);
+ default:
+ /* Unsupported. */
+ return 1;
+ }
+}
+
+static int
+x86_remove_point (char type, CORE_ADDR addr, int len)
+{
+ struct process_info *proc = current_process ();
+ switch (type)
+ {
+ case '2':
+ case '3':
+ case '4':
+ return i386_low_remove_watchpoint (&proc->private->arch_private->debug_reg_state,
+ type, addr, len);
+ default:
+ /* Unsupported. */
+ return 1;
+ }
+}
+
+static int
+x86_stopped_by_watchpoint (void)
+{
+ struct process_info *proc = current_process ();
+ return i386_low_stopped_by_watchpoint (&proc->private->arch_private->debug_reg_state);
+}
+
+static CORE_ADDR
+x86_stopped_data_address (void)
+{
+ struct process_info *proc = current_process ();
+ CORE_ADDR addr;
+ if (i386_low_stopped_data_address (&proc->private->arch_private->debug_reg_state,
+ &addr))
+ return addr;
+ return 0;
+}
+\f
+/* Called when a new process is created. */
+
+static struct arch_process_info *
+x86_linux_new_process (void)
+{
+ struct arch_process_info *info = xcalloc (1, sizeof (*info));
+
+ i386_low_init_dregs (&info->debug_reg_state);
+
+ return info;
+}
+
+/* Called when a new thread is detected. */
+
+static struct arch_lwp_info *
+x86_linux_new_thread (void)
+{
+ struct arch_lwp_info *info = xcalloc (1, sizeof (*info));
+
+ info->debug_registers_changed = 1;
+
+ return info;
+}
+
+/* Called when resuming a thread.
+ If the debug regs have changed, update the thread's copies. */
+
+static void
+x86_linux_prepare_to_resume (struct lwp_info *lwp)
+{
+ if (lwp->arch_private->debug_registers_changed)
+ {
+ int i;
+ ptid_t ptid = ptid_of (lwp);
+ int pid = ptid_get_pid (ptid);
+ struct process_info *proc = find_process_pid (pid);
+ struct i386_debug_reg_state *state = &proc->private->arch_private->debug_reg_state;
+
+ for (i = DR_FIRSTADDR; i <= DR_LASTADDR; i++)
+ x86_linux_dr_set (ptid, i, state->dr_mirror[i]);
+
+ x86_linux_dr_set (ptid, DR_CONTROL, state->dr_control_mirror);
+
+ lwp->arch_private->debug_registers_changed = 0;
+ }
+}
+\f
/* When GDBSERVER is built as a 64-bit application on linux, the
PTRACE_GETSIGINFO data is always presented in 64-bit layout. Since
debugging a 32-bit inferior with a 64-bit GDBSERVER should look the same
@@ -630,10 +839,10 @@ struct linux_target_ops the_low_target =
NULL,
1,
x86_breakpoint_at,
- NULL,
- NULL,
- NULL,
- NULL,
+ x86_insert_point,
+ x86_remove_point,
+ x86_stopped_by_watchpoint,
+ x86_stopped_data_address,
/* collect_ptrace_register/supply_ptrace_register are not needed in the
native i386 case (no registers smaller than an xfer unit), and are not
used in the biarch case (HAVE_LINUX_USRREGS is not defined). */
@@ -641,4 +850,7 @@ struct linux_target_ops the_low_target =
NULL,
/* need to fix up i386 siginfo if host is amd64 */
x86_siginfo_fixup,
+ x86_linux_new_process,
+ x86_linux_new_thread,
+ x86_linux_prepare_to_resume
};
Index: server.c
===================================================================
RCS file: /cvs/src/src/gdb/gdbserver/server.c,v
retrieving revision 1.101
diff -u -p -r1.101 server.c
--- server.c 25 Jun 2009 22:13:52 -0000 1.101
+++ server.c 30 Jun 2009 09:15:58 -0000
@@ -51,6 +51,9 @@ static char **program_argv, **wrapper_ar
was originally used to debug LinuxThreads support. */
int debug_threads;
+/* Enable debugging of h/w breakpoint/watchpoint support. */
+int debug_hw_points;
+
int pass_signals[TARGET_SIGNAL_LAST];
jmp_buf toplevel;
@@ -495,6 +498,8 @@ monitor_show_help (void)
monitor_output ("The following monitor commands are supported:\n");
monitor_output (" set debug <0|1>\n");
monitor_output (" Enable general debugging messages\n");
+ monitor_output (" set debug-hw-points <0|1>\n");
+ monitor_output (" Enable h/w breakpoint/watchpoint debugging messages\n");
monitor_output (" set remote-debug <0|1>\n");
monitor_output (" Enable remote protocol debugging messages\n");
monitor_output (" exit\n");
@@ -1216,6 +1221,16 @@ handle_query (char *own_buf, int packet_
debug_threads = 0;
monitor_output ("Debug output disabled.\n");
}
+ else if (strcmp (mon, "set debug-hw-points 1") == 0)
+ {
+ debug_hw_points = 1;
+ monitor_output ("H/W point debugging output enabled.\n");
+ }
+ else if (strcmp (mon, "set debug-hw-points 0") == 0)
+ {
+ debug_hw_points = 0;
+ monitor_output ("H/W point debugging output disabled.\n");
+ }
else if (strcmp (mon, "set remote-debug 1") == 0)
{
remote_debug = 1;
Index: server.h
===================================================================
RCS file: /cvs/src/src/gdb/gdbserver/server.h,v
retrieving revision 1.58
diff -u -p -r1.58 server.h
--- server.h 24 May 2009 21:06:53 -0000 1.58
+++ server.h 30 Jun 2009 09:15:58 -0000
@@ -271,6 +271,7 @@ extern ptid_t step_thread;
extern int server_waiting;
extern int debug_threads;
+extern int debug_hw_points;
extern int pass_signals[];
extern jmp_buf toplevel;
@@ -407,6 +408,7 @@ void perror_with_name (const char *strin
void error (const char *string,...) ATTR_NORETURN ATTR_FORMAT (printf, 1, 2);
void fatal (const char *string,...) ATTR_NORETURN ATTR_FORMAT (printf, 1, 2);
void warning (const char *string,...) ATTR_FORMAT (printf, 1, 2);
+char *paddress (CORE_ADDR addr);
/* Maximum number of bytes to read/write at once. The value here
is chosen to fill up a packet (the headers account for the 32). */
Index: win32-arm-low.c
===================================================================
RCS file: /cvs/src/src/gdb/gdbserver/win32-arm-low.c,v
retrieving revision 1.8
diff -u -p -r1.8 win32-arm-low.c
--- win32-arm-low.c 3 Jan 2009 05:57:57 -0000 1.8
+++ win32-arm-low.c 30 Jun 2009 09:15:58 -0000
@@ -122,4 +122,9 @@ struct win32_target_ops the_low_target =
NULL, /* single_step */
(const unsigned char *) &arm_wince_breakpoint,
arm_wince_breakpoint_len,
+ /* Watchpoint related functions. See target.h for comments. */
+ NULL, /* insert_point */
+ NULL, /* remove_point */
+ NULL, /* stopped_by_watchpoint */
+ NULL /* stopped_data_address */
};
Index: win32-i386-low.c
===================================================================
RCS file: /cvs/src/src/gdb/gdbserver/win32-i386-low.c,v
retrieving revision 1.14
diff -u -p -r1.14 win32-i386-low.c
--- win32-i386-low.c 3 Jan 2009 05:57:57 -0000 1.14
+++ win32-i386-low.c 30 Jun 2009 09:15:58 -0000
@@ -17,6 +17,7 @@
#include "server.h"
#include "win32-low.h"
+#include "i386-low.h"
#define FCS_REGNUM 27
#define FOP_REGNUM 31
@@ -26,15 +27,101 @@
/* Defined in auto-generated file reg-i386.c. */
void init_registers_i386 (void);
-static unsigned dr[8];
+static struct i386_debug_reg_state debug_reg_state;
static int debug_registers_changed = 0;
static int debug_registers_used = 0;
+/* Update the inferior's debug register REGNUM from STATE. */
+
+void
+i386_dr_low_set_addr (const struct i386_debug_reg_state *state, int regnum)
+{
+ if (! (regnum >= 0 && regnum <= DR_LASTADDR - DR_FIRSTADDR))
+ fatal ("Invalid debug register %d", regnum);
+
+ /* debug_reg_state.dr_mirror is already set.
+ Just notify i386_set_thread_context, i386_thread_added
+ that the registers need to be updated. */
+ debug_registers_changed = 1;
+ debug_registers_used = 1;
+}
+
+/* Update the inferior's DR7 debug control register from STATE. */
+
+void
+i386_dr_low_set_control (const struct i386_debug_reg_state *state)
+{
+ /* debug_reg_state.dr_control_mirror is already set.
+ Just notify i386_set_thread_context, i386_thread_added
+ that the registers need to be updated. */
+ debug_registers_changed = 1;
+ debug_registers_used = 1;
+}
+
+/* Get the value of the DR6 debug status register from the inferior
+ and record it in STATE. */
+
+void
+i386_dr_low_get_status (struct i386_debug_reg_state *state)
+{
+ /* We don't need to do anything here, the last call to thread_rec for
+ current_event.dwThreadId id has already set it. */
+}
+
+/* Watchpoint support. */
+
+static int
+i386_insert_point (char type, CORE_ADDR addr, int len)
+{
+ switch (type)
+ {
+ case '2':
+ case '3':
+ case '4':
+ return i386_low_insert_watchpoint (&debug_reg_state,
+ type, addr, len);
+ default:
+ /* Unsupported. */
+ return 1;
+ }
+}
+
+static int
+i386_remove_point (char type, CORE_ADDR addr, int len)
+{
+ switch (type)
+ {
+ case '2':
+ case '3':
+ case '4':
+ return i386_low_remove_watchpoint (&debug_reg_state,
+ type, addr, len);
+ default:
+ /* Unsupported. */
+ return 1;
+ }
+}
+
+static int
+i386_stopped_by_watchpoint (void)
+{
+ return i386_low_stopped_by_watchpoint (&debug_reg_state);
+}
+
+static CORE_ADDR
+i386_stopped_data_address (void)
+{
+ CORE_ADDR addr;
+ if (i386_low_stopped_data_address (&debug_reg_state, &addr))
+ return addr;
+ return 0;
+}
+
static void
i386_initial_stuff (void)
{
- memset (&dr, 0, sizeof (dr));
+ i386_low_init_dregs (&debug_reg_state);
debug_registers_changed = 0;
debug_registers_used = 0;
}
@@ -55,12 +142,13 @@ i386_get_thread_context (win32_thread_in
if (th->tid == current_event->dwThreadId)
{
/* Copy dr values from the current thread. */
- dr[0] = th->context.Dr0;
- dr[1] = th->context.Dr1;
- dr[2] = th->context.Dr2;
- dr[3] = th->context.Dr3;
- dr[6] = th->context.Dr6;
- dr[7] = th->context.Dr7;
+ struct i386_debug_reg_state *dr = &debug_reg_state;
+ dr->dr_mirror[0] = th->context.Dr0;
+ dr->dr_mirror[1] = th->context.Dr1;
+ dr->dr_mirror[2] = th->context.Dr2;
+ dr->dr_mirror[3] = th->context.Dr3;
+ dr->dr_status_mirror = th->context.Dr6;
+ dr->dr_control_mirror = th->context.Dr7;
}
}
@@ -69,13 +157,14 @@ i386_set_thread_context (win32_thread_in
{
if (debug_registers_changed)
{
- th->context.Dr0 = dr[0];
- th->context.Dr1 = dr[1];
- th->context.Dr2 = dr[2];
- th->context.Dr3 = dr[3];
- /* th->context.Dr6 = dr[6];
+ struct i386_debug_reg_state *dr = &debug_reg_state;
+ th->context.Dr0 = dr->dr_mirror[0];
+ th->context.Dr1 = dr->dr_mirror[1];
+ th->context.Dr2 = dr->dr_mirror[2];
+ th->context.Dr3 = dr->dr_mirror[3];
+ /* th->context.Dr6 = dr->dr_status_mirror;
FIXME: should we set dr6 also ?? */
- th->context.Dr7 = dr[7];
+ th->context.Dr7 = dr->dr_control_mirror;
}
SetThreadContext (th->h, &th->context);
@@ -87,16 +176,17 @@ i386_thread_added (win32_thread_info *th
/* Set the debug registers for the new thread if they are used. */
if (debug_registers_used)
{
+ struct i386_debug_reg_state *dr = &debug_reg_state;
th->context.ContextFlags = CONTEXT_DEBUG_REGISTERS;
GetThreadContext (th->h, &th->context);
- th->context.Dr0 = dr[0];
- th->context.Dr1 = dr[1];
- th->context.Dr2 = dr[2];
- th->context.Dr3 = dr[3];
- /* th->context.Dr6 = dr[6];
+ th->context.Dr0 = dr->dr_mirror[0];
+ th->context.Dr1 = dr->dr_mirror[1];
+ th->context.Dr2 = dr->dr_mirror[2];
+ th->context.Dr3 = dr->dr_mirror[3];
+ /* th->context.Dr6 = dr->dr_status_mirror;
FIXME: should we set dr6 also ?? */
- th->context.Dr7 = dr[7];
+ th->context.Dr7 = dr->dr_control_mirror;
SetThreadContext (th->h, &th->context);
th->context.ContextFlags = 0;
@@ -205,4 +295,8 @@ struct win32_target_ops the_low_target =
i386_single_step,
NULL, /* breakpoint */
0, /* breakpoint_len */
+ i386_insert_point,
+ i386_remove_point,
+ i386_stopped_by_watchpoint,
+ i386_stopped_data_address
};
Index: win32-low.c
===================================================================
RCS file: /cvs/src/src/gdb/gdbserver/win32-low.c,v
retrieving revision 1.36
diff -u -p -r1.36 win32-low.c
--- win32-low.c 22 Jun 2009 19:33:41 -0000 1.36
+++ win32-low.c 30 Jun 2009 09:15:58 -0000
@@ -228,6 +228,48 @@ child_delete_thread (DWORD pid, DWORD ti
delete_thread_info (thread);
}
+/* These watchpoint related wrapper functions simply pass on the function call
+ if the low target has registered a corresponding function. */
+
+static int
+win32_insert_point (char type, CORE_ADDR addr, int len)
+{
+ if (the_low_target.insert_point != NULL)
+ return the_low_target.insert_point (type, addr, len);
+ else
+ /* Unsupported (see target.h). */
+ return 1;
+}
+
+static int
+win32_remove_point (char type, CORE_ADDR addr, int len)
+{
+ if (the_low_target.remove_point != NULL)
+ return the_low_target.remove_point (type, addr, len);
+ else
+ /* Unsupported (see target.h). */
+ return 1;
+}
+
+static int
+win32_stopped_by_watchpoint (void)
+{
+ if (the_low_target.stopped_by_watchpoint != NULL)
+ return the_low_target.stopped_by_watchpoint ();
+ else
+ return 0;
+}
+
+static CORE_ADDR
+win32_stopped_data_address (void)
+{
+ if (the_low_target.stopped_data_address != NULL)
+ return the_low_target.stopped_data_address ();
+ else
+ return 0;
+}
+
+
/* Transfer memory from/to the debugged process. */
static int
child_xfer_memory (CORE_ADDR memaddr, char *our, int len,
@@ -1697,10 +1739,10 @@ static struct target_ops win32_target_op
NULL,
win32_request_interrupt,
NULL,
- NULL,
- NULL,
- NULL,
- NULL,
+ win32_insert_point,
+ win32_remove_point,
+ win32_stopped_by_watchpoint,
+ win32_stopped_data_address,
NULL,
NULL,
NULL,
Index: win32-low.h
===================================================================
RCS file: /cvs/src/src/gdb/gdbserver/win32-low.h,v
retrieving revision 1.9
diff -u -p -r1.9 win32-low.h
--- win32-low.h 3 Jan 2009 05:57:57 -0000 1.9
+++ win32-low.h 30 Jun 2009 09:15:58 -0000
@@ -70,6 +70,12 @@ struct win32_target_ops
const unsigned char *breakpoint;
int breakpoint_len;
+
+ /* Breakpoint/Watchpoint related functions. See target.h for comments. */
+ int (*insert_point) (char type, CORE_ADDR addr, int len);
+ int (*remove_point) (char type, CORE_ADDR addr, int len);
+ int (*stopped_by_watchpoint) (void);
+ CORE_ADDR (*stopped_data_address) (void);
};
extern struct win32_target_ops the_low_target;
Index: utils.c
===================================================================
RCS file: /cvs/src/src/gdb/gdbserver/utils.c,v
retrieving revision 1.18
diff -u -p -r1.18 utils.c
--- utils.c 19 Jan 2009 00:16:46 -0000 1.18
+++ utils.c 30 Jun 2009 09:49:34 -0000
@@ -170,3 +170,46 @@ warning (const char *string,...)
fprintf (stderr, "\n");
va_end (args);
}
+
+/* Temporary storage using circular buffer. */
+#define NUMCELLS 4
+#define CELLSIZE 50
+
+/* Return the next entry in the circular buffer. */
+
+static char *
+get_cell (void)
+{
+ static char buf[NUMCELLS][CELLSIZE];
+ static int cell = 0;
+ if (++cell >= NUMCELLS)
+ cell = 0;
+ return buf[cell];
+}
+
+/* Stdarg wrapper around vsnprintf.
+ SIZE is the size of the buffer pointed to by STR. */
+
+static int
+xsnprintf (char *str, size_t size, const char *format, ...)
+{
+ va_list args;
+ int ret;
+
+ va_start (args, format);
+ ret = vsnprintf (str, size, format, args);
+ va_end (args);
+
+ return ret;
+}
+
+/* Convert a CORE_ADDR into a HEX string, like %lx.
+ The result is stored in a circular static buffer, NUMCELLS deep. */
+
+char *
+paddress (CORE_ADDR addr)
+{
+ char *str = get_cell ();
+ xsnprintf (str, CELLSIZE, "%lx", (long) addr);
+ return str;
+}
^ permalink raw reply [flat|nested] 18+ messages in thread
* Re: [RFA] i386/amd64 h/w watchpoints in gdbserver
2009-06-30 10:32 ` Doug Evans
@ 2009-06-30 10:56 ` Pedro Alves
2009-06-30 15:58 ` Pierre Muller
1 sibling, 0 replies; 18+ messages in thread
From: Pedro Alves @ 2009-06-30 10:56 UTC (permalink / raw)
To: Doug Evans; +Cc: Pierre Muller, gdb-patches
Ok. Thanks much for your the patience!
--
Pedro Alves
^ permalink raw reply [flat|nested] 18+ messages in thread
* RE: [RFA] i386/amd64 h/w watchpoints in gdbserver
2009-06-30 10:32 ` Doug Evans
2009-06-30 10:56 ` Pedro Alves
@ 2009-06-30 15:58 ` Pierre Muller
1 sibling, 0 replies; 18+ messages in thread
From: Pierre Muller @ 2009-06-30 15:58 UTC (permalink / raw)
To: 'Doug Evans', 'Pedro Alves'; +Cc: gdb-patches
> Pierre, nothing much has changed win32-wise except some functions got
> renamed.
> I don't know if you want to first give this a spin again or not.
I compiled it out of the box,
and tested it on the gdb.*/wa*.exp pattern and it seems
to give the same results as before.
Good to go in for me!
Pierre Muller
Pascal language support maintainer for GDB
^ permalink raw reply [flat|nested] 18+ messages in thread
end of thread, other threads:[~2009-06-30 15:58 UTC | newest]
Thread overview: 18+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2009-04-30 7:19 [RFA] i386/amd64 h/w watchpoints in gdbserver Doug Evans
2009-05-01 8:10 ` Pierre Muller
2009-05-18 23:11 ` Doug Evans
2009-05-18 23:28 ` Doug Evans
2009-05-19 9:05 ` Pierre Muller
2009-06-02 15:36 ` Doug Evans
2009-06-02 22:47 ` Pierre Muller
2009-06-03 0:18 ` Doug Evans
2009-06-03 16:27 ` Pierre Muller
2009-06-09 3:43 ` Doug Evans
2009-06-10 5:05 ` Pierre Muller
2009-06-18 19:04 ` Doug Evans
2009-06-20 23:54 ` Pedro Alves
2009-06-23 7:37 ` Doug Evans
2009-06-29 20:45 ` Pedro Alves
2009-06-30 10:32 ` Doug Evans
2009-06-30 10:56 ` Pedro Alves
2009-06-30 15:58 ` Pierre Muller
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