old-cross-binutils/gdb/nat/x86-dregs.h
Gary Benson 97ea6506c4 x86 debug address register clarifications
The loop macro ALL_DEBUG_REGISTERS does not iterate over the status or
control registers, so its name is misleading.  This commit renames it
as ALL_DEBUG_ADDRESS_REGISTERS and updates all uses.  This commit also
updates its loop conditions to an equivalent but better form, and
makes two functions use it that had previously hardwired the loop.
A comment on a related field in the x86_debug_reg_state structure is
also updated to reflect that the field refers specifically to address
registers only.

gdb/ChangeLog:

	* nat/x86-dregs.h (ALL_DEBUG_REGISTERS): Renamed as...
	(ALL_DEBUG_ADDRESS_REGISTERS): New macro.  All uses updated.
	Loop conditions	changed to equivalent form.
	(struct x86_debug_reg_state): Updated dr_ref_count comment.
	* x86-linux-nat.c (x86_linux_prepare_to_resume): Use
	ALL_DEBUG_ADDRESS_REGISTERS.

gdb/gdbserver/ChangeLog:

	* linux-x86-low.c (x86_linux_prepare_to_resume): Use
	ALL_DEBUG_ADDRESS_REGISTERS.
2014-09-03 12:40:49 +01:00

127 lines
4.6 KiB
C

/* Debug register code for x86 (i386 and x86-64).
Copyright (C) 2009-2014 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/>. */
/* Support for hardware watchpoints and breakpoints using the x86
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). */
#ifndef X86_DREGS_H
#define X86_DREGS_H 1
/* Forward declaration. */
enum target_hw_bp_type;
/* Low-level function vector. */
struct x86_dr_low_type
{
/* Set the debug control (DR7) register to a given value for
all LWPs. May be NULL if the debug control register cannot
be set. */
void (*set_control) (unsigned long);
/* Put an address into one debug register for all LWPs. May
be NULL if debug registers cannot be set*/
void (*set_addr) (int, CORE_ADDR);
/* Return the address in a given debug register of the current
LWP. */
CORE_ADDR (*get_addr) (int);
/* Return the value of the debug status (DR6) register for
current LWP. */
unsigned long (*get_status) (void);
/* Return the value of the debug control (DR7) register for
current LWP. */
unsigned long (*get_control) (void);
/* Number of bytes used for debug registers (4 or 8). */
int debug_register_length;
};
extern struct x86_dr_low_type x86_dr_low;
/* 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 /* Index of debug status register (DR6). */
#define DR_CONTROL 7 /* Index of debug control register (DR7). */
/* Global state needed to track h/w watchpoints. */
struct x86_debug_reg_state
{
/* Mirror the inferior's DRi registers. We keep the status and
control registers separated because they don't hold addresses.
Note that since we can change these mirrors while threads are
running, we never trust them to explain a cause of a trap.
For that, we need to peek directly in the inferior registers. */
CORE_ADDR dr_mirror[DR_NADDR];
unsigned dr_status_mirror, dr_control_mirror;
/* Reference counts for each debug address register. */
int dr_ref_count[DR_NADDR];
};
/* A macro to loop over all debug address registers. */
#define ALL_DEBUG_ADDRESS_REGISTERS(i) \
for (i = DR_FIRSTADDR; i <= DR_LASTADDR; i++)
/* 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. Return 0 on success, -1 on failure. */
extern int x86_dr_insert_watchpoint (struct x86_debug_reg_state *state,
enum target_hw_bp_type type,
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. Return 0 on success, -1 on failure. */
extern int x86_dr_remove_watchpoint (struct x86_debug_reg_state *state,
enum target_hw_bp_type type,
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 x86_dr_region_ok_for_watchpoint (struct x86_debug_reg_state *state,
CORE_ADDR addr, int len);
/* If the inferior has some break/watchpoint that triggered, set the
address associated with that break/watchpoint and return true.
Otherwise, return false. */
extern int x86_dr_stopped_data_address (struct x86_debug_reg_state *state,
CORE_ADDR *addr_p);
/* Return true if the inferior has some watchpoint that triggered.
Otherwise return false. */
extern int x86_dr_stopped_by_watchpoint (struct x86_debug_reg_state *state);
#endif /* X86_DREGS_H */