[RFA] i386/amd64 h/w watchpoints in gdbserver

Doug Evans
2009-04-30T07:19:22Z

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;