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

Pierre Muller
2009-05-01T08:10:54Z

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;