binutils-gdb/gdb/gdbserver/win32-arm-low.c
Pedro Alves a2abc7de68 gdbserver/win32: Rewrite debug registers handling
Don't use debug_reg_state for both:

 * "intent" - what we want the debug registers to look like

 * "reality" - what/which were the contents of the DR registers when
   the event triggered

Reserve it for the former only, like in the GNU/Linux port.

Otherwise the core x86 debug registers code can get confused if the
inferior itself changes the debug registers since GDB last set them.

This is also a requirement for being able to set watchpoints while the
target is running, if/when we get to it on Windows.  See the big
comment in x86_dr_stopped_data_address.

Seems to me this may also fixes propagating watchpoints to all threads
-- continue_one_thread only calls win32_set_thread_context (what
copies the DR registers to the thread), if something already fetched
the thread's context before.  Something else may be masking this
issue, I haven't checked.

Smoke tested by running gdbserver under Wine, connecting to it from
GNU/Linux, and checking that I could trigger a watchpoint as expected.

Joel tested it on x86-windows using AdaCore's testsuite.

gdb/gdbserver/
2014-10-15  Pedro Alves  <palves@redhat.com>

	PR server/17487
	* win32-arm-low.c (arm_set_thread_context): Remove current_event
	parameter.
	(arm_set_thread_context): Delete.
	(the_low_target): Adjust.
	* win32-i386-low.c (debug_registers_changed)
	(debug_registers_used): Delete.
	(update_debug_registers_callback): New function.
	(x86_dr_low_set_addr, x86_dr_low_set_control): Mark all threads as
	needing to update their debug registers.
	(win32_get_current_dr): New function.
	(x86_dr_low_get_addr, x86_dr_low_get_control)
	(x86_dr_low_get_status): Fetch the debug register from the thread
	record's context.
	(i386_initial_stuff): Adjust.
	(i386_get_thread_context): Remove current_event parameter.  Don't
	clear debug_registers_changed nor copy DR values to
	debug_reg_state.
	(i386_set_thread_context): Delete.
	(i386_prepare_to_resume): New function.
	(i386_thread_added): Mark the thread as needing to update irs
	debug registers.
	(the_low_target): Remove i386_set_thread_context and install
	i386_prepare_to_resume.
	* win32-low.c (win32_get_thread_context): Adjust.
	(win32_set_thread_context): Use SetThreadContext
	directly.
	(win32_prepare_to_resume): New function.
	(win32_require_context): New function, factored out from ...
	(thread_rec): ... this.
	(continue_one_thread): Call win32_prepare_to_resume on each thread
	we're about to continue.
	(win32_resume): Call win32_prepare_to_resume on the event thread.
	* win32-low.h (struct win32_thread_info)
	<debug_registers_changed>: New field.
	(struct win32_target_ops): Change prototype of set_thread_context,
	delete set_thread_context and add prepare_to_resume.
	(win32_require_context): New declaration.
2014-10-15 19:55:50 +01:00

135 lines
3.6 KiB
C

/* Copyright (C) 2007-2014 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 "win32-low.h"
#ifndef CONTEXT_FLOATING_POINT
#define CONTEXT_FLOATING_POINT 0
#endif
/* Defined in auto-generated file reg-arm.c. */
void init_registers_arm (void);
extern const struct target_desc *tdesc_arm;
static void
arm_get_thread_context (win32_thread_info *th)
{
th->context.ContextFlags = \
CONTEXT_FULL | \
CONTEXT_FLOATING_POINT;
GetThreadContext (th->h, &th->context);
}
#define context_offset(x) ((int)&(((CONTEXT *)NULL)->x))
static const int mappings[] = {
context_offset (R0),
context_offset (R1),
context_offset (R2),
context_offset (R3),
context_offset (R4),
context_offset (R5),
context_offset (R6),
context_offset (R7),
context_offset (R8),
context_offset (R9),
context_offset (R10),
context_offset (R11),
context_offset (R12),
context_offset (Sp),
context_offset (Lr),
context_offset (Pc),
-1, /* f0 */
-1, /* f1 */
-1, /* f2 */
-1, /* f3 */
-1, /* f4 */
-1, /* f5 */
-1, /* f6 */
-1, /* f7 */
-1, /* fps */
context_offset (Psr),
};
#undef context_offset
/* Return a pointer into a CONTEXT field indexed by gdb register number.
Return a pointer to an dummy register holding zero if there is no
corresponding CONTEXT field for the given register number. */
static char *
regptr (CONTEXT* c, int r)
{
if (mappings[r] < 0)
{
static ULONG zero;
/* Always force value to zero, in case the user tried to write
to this register before. */
zero = 0;
return (char *) &zero;
}
else
return (char *) c + mappings[r];
}
/* Fetch register from gdbserver regcache data. */
static void
arm_fetch_inferior_register (struct regcache *regcache,
win32_thread_info *th, int r)
{
char *context_offset = regptr (&th->context, r);
supply_register (regcache, r, context_offset);
}
/* Store a new register value into the thread context of TH. */
static void
arm_store_inferior_register (struct regcache *regcache,
win32_thread_info *th, int r)
{
collect_register (regcache, r, regptr (&th->context, r));
}
static void
arm_arch_setup (void)
{
init_registers_arm ();
win32_tdesc = tdesc_arm;
}
/* Correct in either endianness. We do not support Thumb yet. */
static const unsigned long arm_wince_breakpoint = 0xe6000010;
#define arm_wince_breakpoint_len 4
struct win32_target_ops the_low_target = {
arm_arch_setup,
sizeof (mappings) / sizeof (mappings[0]),
NULL, /* initial_stuff */
arm_get_thread_context,
NULL, /* prepare_to_resume */
NULL, /* thread_added */
arm_fetch_inferior_register,
arm_store_inferior_register,
NULL, /* single_step */
(const unsigned char *) &arm_wince_breakpoint,
arm_wince_breakpoint_len,
/* Watchpoint related functions. See target.h for comments. */
NULL, /* supports_z_point_type */
NULL, /* insert_point */
NULL, /* remove_point */
NULL, /* stopped_by_watchpoint */
NULL /* stopped_data_address */
};