Unified support for hardware breakpoints and watchpoints on
x86 targets:
* config/i386/nm-i386.h: New file.
* config/i386/nm-i386.h: (i386_cleanup_dregs)
(i386_insert_watchpoint, i386_remove_watchpoint)
(i386_region_ok_for_watchpoint, i386_stopped_by_hwbp)
(i386_stopped_data_address, i386_insert_hw_breakpoint)
(i386_remove_hw_breakpoint): Declare prototypes.
[I386_USE_GENERIC_WATCHPOINTS] (TARGET_CAN_USE_HARDWARE_WATCHPOINT):
Define if not already defined.
(TARGET_REGION_OK_FOR_HW_WATCHPOINT, HAVE_CONTINUABLE_WATCHPOINT)
(STOPPED_BY_WATCHPOINT, target_stopped_data_address)
(target_insert_watchpoint, target_remove_watchpoint)
(target_insert_hw_breakpoint, target_remove_hw_breakpoint): Define
to call the appropriate i386_* functions.
* i386-nat.c: New file.
* i386-nat.c (I386_DR_CONTROL_MASK, I386_DR_LOCAL_ENABLE)
(I386_DR_GLOBAL_ENABLE, I386_DR_DISABLE, I386_DR_SET_RW_LEN)
(I386_DR_GET_RW_LEN, I386_DR_WATCH_HIT): New macros.
(dr_mirror, dr_status_mirror, dr_control_mirror, dr_ref_count)
(maint_show_dr): New variables.
(i386_cleanup_dregs, i386_show_dr, i386_length_and_rw_bits)
(i386_insert_aligned_watchpoint, i386_remove_aligned_watchpoint)
(i386_handle_nonaligned_watchpoint, i386_insert_watchpoint)
(i386_remove_watchpoint, i386_region_ok_for_watchpoint)
(i386_stopped_data_address, i386_stopped_by_hwbp)
(i386_insert_hw_breakpoint, i386_remove_hw_breakpoint): New
functions.
(_initialize_i386_nat): New function.
[I386_USE_GENERIC_WATCHPOINTS]: Add new maint command
`show-debug-regs', sets maint_show_dr to non-zero value and
activates debugging print-outs in functions which insert, remove,
and test watchpoints and hardware breakpoints.
* Makefile.in (i386-nat.o): New target.
(ALLDEPFILES): Add i386-nat.o.
2001-03-21 12:36:58 +01:00
|
|
|
|
/* Intel x86 (a.k.a. ia32) native-dependent code.
|
|
|
|
|
Copyright (C) 2001 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 2 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, write to the Free Software
|
|
|
|
|
Foundation, Inc., 59 Temple Place - Suite 330,
|
|
|
|
|
Boston, MA 02111-1307, USA. */
|
|
|
|
|
|
|
|
|
|
#include "defs.h"
|
|
|
|
|
#include "breakpoint.h"
|
|
|
|
|
#include "command.h"
|
|
|
|
|
#include "gdbcmd.h"
|
|
|
|
|
|
|
|
|
|
/* 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 triggerd and at what address,
|
|
|
|
|
checking whether a given region can be watched, etc.
|
|
|
|
|
|
|
|
|
|
A target which wants to use these functions should define
|
|
|
|
|
several macros, such as `target_insert_watchpoint' and
|
|
|
|
|
`target_stopped_data_address', listed in target.h, to call
|
|
|
|
|
the appropriate functions below. It should also define
|
|
|
|
|
I386_USE_GENERIC_WATCHPOINTS in its tm.h file.
|
|
|
|
|
|
|
|
|
|
In addition, each target should provide several low-level
|
|
|
|
|
macros that will be called to insert watchpoints and hardware
|
|
|
|
|
breakpoints into the inferior, remove them, and check their
|
|
|
|
|
status. These macros 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_RESET_ADDR -- reset the address stored in
|
|
|
|
|
one debug register
|
|
|
|
|
|
|
|
|
|
I386_DR_LOW_GET_STATUS -- return the value of the debug
|
|
|
|
|
status (DR6) register.
|
|
|
|
|
|
|
|
|
|
The functions below implement debug registers sharing by
|
|
|
|
|
reference counts, and allow to watch regions up to 16 bytes
|
|
|
|
|
long. */
|
|
|
|
|
|
|
|
|
|
#ifdef I386_USE_GENERIC_WATCHPOINTS
|
|
|
|
|
|
|
|
|
|
/* Debug registers' indices. */
|
|
|
|
|
#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) */
|
|
|
|
|
|
|
|
|
|
/* 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 Mar-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 breakpt */
|
|
|
|
|
#define DR_LEN_2 (0x1 << 2) /* 2-byte region watch */
|
|
|
|
|
#define DR_LEN_4 (0x3 << 2) /* 4-byte region watch */
|
|
|
|
|
|
|
|
|
|
/* 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 /* 2 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
|
|
|
|
|
back 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(i) \
|
|
|
|
|
((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(i) \
|
|
|
|
|
dr_control_mirror |= (1 << (DR_LOCAL_ENABLE_SHIFT + DR_ENABLE_SIZE * (i)))
|
|
|
|
|
|
|
|
|
|
/* Globally enable the break/watchpoint in the I'th debug register. */
|
|
|
|
|
#define I386_DR_GLOBAL_ENABLE(i) \
|
|
|
|
|
dr_control_mirror |= (1 << (DR_GLOBAL_ENABLE_SHIFT + DR_ENABLE_SIZE * (i)))
|
|
|
|
|
|
|
|
|
|
/* Disable the break/watchpoint in the I'th debug register. */
|
|
|
|
|
#define I386_DR_DISABLE(i) \
|
|
|
|
|
dr_control_mirror &= ~(3 << (DR_ENABLE_SIZE * (i)))
|
|
|
|
|
|
|
|
|
|
/* Set in DR7 the RW and LEN fields for the I'th debug register. */
|
|
|
|
|
#define I386_DR_SET_RW_LEN(i,rwlen) \
|
|
|
|
|
do { \
|
|
|
|
|
dr_control_mirror &= ~(0x0f << (DR_CONTROL_SHIFT+DR_CONTROL_SIZE*(i))); \
|
|
|
|
|
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(i) \
|
|
|
|
|
((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(i) (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++)
|
|
|
|
|
|
|
|
|
|
/* Mirror the inferior's DRi registers. We keep the status and
|
|
|
|
|
control registers separated because they don't hold addresses. */
|
|
|
|
|
static CORE_ADDR dr_mirror[DR_NADDR];
|
|
|
|
|
static unsigned dr_status_mirror, dr_control_mirror;
|
|
|
|
|
|
|
|
|
|
/* Reference counts for each debug register. */
|
|
|
|
|
static int dr_ref_count[DR_NADDR];
|
|
|
|
|
|
|
|
|
|
/* Whether or not to print the mirrored debug registers. */
|
|
|
|
|
static int maint_show_dr;
|
|
|
|
|
|
|
|
|
|
/* 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 (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 (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 (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_cleanup_dregs (void)
|
|
|
|
|
{
|
|
|
|
|
int i;
|
|
|
|
|
|
|
|
|
|
ALL_DEBUG_REGISTERS(i)
|
|
|
|
|
{
|
|
|
|
|
dr_mirror[i] = 0;
|
|
|
|
|
dr_ref_count[i] = 0;
|
|
|
|
|
}
|
|
|
|
|
dr_control_mirror = 0;
|
|
|
|
|
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 (const char *func, CORE_ADDR addr,
|
|
|
|
|
int len, enum target_hw_bp_type type)
|
|
|
|
|
{
|
|
|
|
|
int i;
|
|
|
|
|
|
|
|
|
|
puts_unfiltered (func);
|
|
|
|
|
if (addr || len)
|
|
|
|
|
printf_unfiltered (" (addr=%lx, len=%d, type=%s)",
|
|
|
|
|
/* This code is for ia32, so casting CORE_ADDR
|
|
|
|
|
to unsigned long should be okay. */
|
|
|
|
|
(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??"))));
|
|
|
|
|
puts_unfiltered (":\n");
|
|
|
|
|
printf_unfiltered ("\tCONTROL (DR7): %08x STATUS (DR6): %08x\n",
|
|
|
|
|
dr_control_mirror, dr_status_mirror);
|
|
|
|
|
ALL_DEBUG_REGISTERS(i)
|
|
|
|
|
{
|
|
|
|
|
printf_unfiltered ("\tDR%d: addr=%08lx, ref.count=%d DR%d: addr=%08lx, ref.count=%d\n",
|
|
|
|
|
i, dr_mirror[i], dr_ref_count[i],
|
|
|
|
|
i+1, dr_mirror[i+1], 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: /* x86 doesn't support data-read watchpoints */
|
|
|
|
|
case hw_access:
|
|
|
|
|
rw = DR_RW_READ;
|
|
|
|
|
break;
|
|
|
|
|
#if 0
|
|
|
|
|
case hw_io_access: /* not yet supported */
|
|
|
|
|
rw = DR_RW_IORW;
|
|
|
|
|
break;
|
|
|
|
|
#endif
|
|
|
|
|
default:
|
|
|
|
|
internal_error (__FILE__, __LINE__, "\
|
|
|
|
|
Invalid hw breakpoint type %d in i386_length_and_rw_bits.\n", (int)type);
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
switch (len)
|
|
|
|
|
{
|
|
|
|
|
case 4:
|
|
|
|
|
return (DR_LEN_4 | rw);
|
|
|
|
|
case 2:
|
|
|
|
|
return (DR_LEN_2 | rw);
|
|
|
|
|
case 1:
|
|
|
|
|
return (DR_LEN_1 | rw);
|
|
|
|
|
default:
|
|
|
|
|
internal_error (__FILE__, __LINE__, "\
|
|
|
|
|
Invalid hw 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 (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 (i)
|
|
|
|
|
&& dr_mirror[i] == addr
|
|
|
|
|
&& I386_DR_GET_RW_LEN (i) == len_rw_bits)
|
|
|
|
|
{
|
|
|
|
|
dr_ref_count[i]++;
|
|
|
|
|
return 0;
|
|
|
|
|
}
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
/* Next, look for a vacant debug register. */
|
|
|
|
|
ALL_DEBUG_REGISTERS(i)
|
|
|
|
|
{
|
|
|
|
|
if (I386_DR_VACANT (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. */
|
|
|
|
|
dr_mirror[i] = addr;
|
|
|
|
|
dr_ref_count[i] = 1;
|
|
|
|
|
I386_DR_SET_RW_LEN (i, len_rw_bits);
|
|
|
|
|
/* Note: we only enable the watchpoint locally, i.e. in the current
|
|
|
|
|
task. Currently, no x86 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 (i);
|
|
|
|
|
dr_control_mirror |= DR_LOCAL_SLOWDOWN;
|
|
|
|
|
dr_control_mirror &= I386_DR_CONTROL_MASK;
|
|
|
|
|
|
|
|
|
|
/* Finally, actually pass the info to the inferior. */
|
|
|
|
|
I386_DR_LOW_SET_ADDR (i, addr);
|
2001-03-31 19:40:04 +02:00
|
|
|
|
I386_DR_LOW_SET_CONTROL (dr_control_mirror);
|
Unified support for hardware breakpoints and watchpoints on
x86 targets:
* config/i386/nm-i386.h: New file.
* config/i386/nm-i386.h: (i386_cleanup_dregs)
(i386_insert_watchpoint, i386_remove_watchpoint)
(i386_region_ok_for_watchpoint, i386_stopped_by_hwbp)
(i386_stopped_data_address, i386_insert_hw_breakpoint)
(i386_remove_hw_breakpoint): Declare prototypes.
[I386_USE_GENERIC_WATCHPOINTS] (TARGET_CAN_USE_HARDWARE_WATCHPOINT):
Define if not already defined.
(TARGET_REGION_OK_FOR_HW_WATCHPOINT, HAVE_CONTINUABLE_WATCHPOINT)
(STOPPED_BY_WATCHPOINT, target_stopped_data_address)
(target_insert_watchpoint, target_remove_watchpoint)
(target_insert_hw_breakpoint, target_remove_hw_breakpoint): Define
to call the appropriate i386_* functions.
* i386-nat.c: New file.
* i386-nat.c (I386_DR_CONTROL_MASK, I386_DR_LOCAL_ENABLE)
(I386_DR_GLOBAL_ENABLE, I386_DR_DISABLE, I386_DR_SET_RW_LEN)
(I386_DR_GET_RW_LEN, I386_DR_WATCH_HIT): New macros.
(dr_mirror, dr_status_mirror, dr_control_mirror, dr_ref_count)
(maint_show_dr): New variables.
(i386_cleanup_dregs, i386_show_dr, i386_length_and_rw_bits)
(i386_insert_aligned_watchpoint, i386_remove_aligned_watchpoint)
(i386_handle_nonaligned_watchpoint, i386_insert_watchpoint)
(i386_remove_watchpoint, i386_region_ok_for_watchpoint)
(i386_stopped_data_address, i386_stopped_by_hwbp)
(i386_insert_hw_breakpoint, i386_remove_hw_breakpoint): New
functions.
(_initialize_i386_nat): New function.
[I386_USE_GENERIC_WATCHPOINTS]: Add new maint command
`show-debug-regs', sets maint_show_dr to non-zero value and
activates debugging print-outs in functions which insert, remove,
and test watchpoints and hardware breakpoints.
* Makefile.in (i386-nat.o): New target.
(ALLDEPFILES): Add i386-nat.o.
2001-03-21 12:36:58 +01:00
|
|
|
|
|
|
|
|
|
return 0;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
/* Remove a watchpoint at address ADDR, which is assumed to be aligned
|
|
|
|
|
according to the length of the region to watch. LEN_RW_BITS is the
|
|
|
|
|
value of the bits from DR7 which describes the length and access
|
|
|
|
|
type of the region watched by this watchpoint. Return 0 on
|
|
|
|
|
success, -1 on failure. */
|
|
|
|
|
static int
|
|
|
|
|
i386_remove_aligned_watchpoint (CORE_ADDR addr, unsigned len_rw_bits)
|
|
|
|
|
{
|
|
|
|
|
int i, retval = -1;
|
|
|
|
|
|
|
|
|
|
ALL_DEBUG_REGISTERS(i)
|
|
|
|
|
{
|
|
|
|
|
if (!I386_DR_VACANT (i)
|
|
|
|
|
&& dr_mirror[i] == addr
|
|
|
|
|
&& I386_DR_GET_RW_LEN (i) == len_rw_bits)
|
|
|
|
|
{
|
|
|
|
|
if (--dr_ref_count[i] == 0) /* no longer in use? */
|
|
|
|
|
{
|
|
|
|
|
/* Reset our mirror. */
|
|
|
|
|
dr_mirror[i] = 0;
|
|
|
|
|
I386_DR_DISABLE (i);
|
|
|
|
|
/* Reset it in the inferior. */
|
|
|
|
|
I386_DR_LOW_SET_CONTROL (dr_control_mirror);
|
2001-03-31 19:40:04 +02:00
|
|
|
|
I386_DR_LOW_RESET_ADDR (i);
|
Unified support for hardware breakpoints and watchpoints on
x86 targets:
* config/i386/nm-i386.h: New file.
* config/i386/nm-i386.h: (i386_cleanup_dregs)
(i386_insert_watchpoint, i386_remove_watchpoint)
(i386_region_ok_for_watchpoint, i386_stopped_by_hwbp)
(i386_stopped_data_address, i386_insert_hw_breakpoint)
(i386_remove_hw_breakpoint): Declare prototypes.
[I386_USE_GENERIC_WATCHPOINTS] (TARGET_CAN_USE_HARDWARE_WATCHPOINT):
Define if not already defined.
(TARGET_REGION_OK_FOR_HW_WATCHPOINT, HAVE_CONTINUABLE_WATCHPOINT)
(STOPPED_BY_WATCHPOINT, target_stopped_data_address)
(target_insert_watchpoint, target_remove_watchpoint)
(target_insert_hw_breakpoint, target_remove_hw_breakpoint): Define
to call the appropriate i386_* functions.
* i386-nat.c: New file.
* i386-nat.c (I386_DR_CONTROL_MASK, I386_DR_LOCAL_ENABLE)
(I386_DR_GLOBAL_ENABLE, I386_DR_DISABLE, I386_DR_SET_RW_LEN)
(I386_DR_GET_RW_LEN, I386_DR_WATCH_HIT): New macros.
(dr_mirror, dr_status_mirror, dr_control_mirror, dr_ref_count)
(maint_show_dr): New variables.
(i386_cleanup_dregs, i386_show_dr, i386_length_and_rw_bits)
(i386_insert_aligned_watchpoint, i386_remove_aligned_watchpoint)
(i386_handle_nonaligned_watchpoint, i386_insert_watchpoint)
(i386_remove_watchpoint, i386_region_ok_for_watchpoint)
(i386_stopped_data_address, i386_stopped_by_hwbp)
(i386_insert_hw_breakpoint, i386_remove_hw_breakpoint): New
functions.
(_initialize_i386_nat): New function.
[I386_USE_GENERIC_WATCHPOINTS]: Add new maint command
`show-debug-regs', sets maint_show_dr to non-zero value and
activates debugging print-outs in functions which insert, remove,
and test watchpoints and hardware breakpoints.
* Makefile.in (i386-nat.o): New target.
(ALLDEPFILES): Add i386-nat.o.
2001-03-21 12:36:58 +01:00
|
|
|
|
}
|
|
|
|
|
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 (i386_wp_op_t what, CORE_ADDR addr, int len,
|
|
|
|
|
enum target_hw_bp_type type)
|
|
|
|
|
{
|
|
|
|
|
int align;
|
|
|
|
|
int size;
|
|
|
|
|
int rv = 0, status = 0;
|
|
|
|
|
|
|
|
|
|
static int size_try_array[4][4] =
|
|
|
|
|
{
|
|
|
|
|
{ 1, 1, 1, 1 }, /* trying size one */
|
|
|
|
|
{ 2, 1, 2, 1 }, /* trying size two */
|
|
|
|
|
{ 2, 1, 2, 1 }, /* trying size three */
|
|
|
|
|
{ 4, 1, 2, 1 } /* trying size four */
|
|
|
|
|
};
|
|
|
|
|
|
|
|
|
|
while (len > 0)
|
|
|
|
|
{
|
|
|
|
|
align = addr % 4;
|
|
|
|
|
/* Four is the maximum length an x86 debug register can watch. */
|
|
|
|
|
size = size_try_array[len > 4 ? 3 : len - 1][align];
|
|
|
|
|
if (what == WP_COUNT)
|
|
|
|
|
/* size_try_array[] is defined so 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. */
|
|
|
|
|
rv++;
|
|
|
|
|
else
|
|
|
|
|
{
|
|
|
|
|
unsigned len_rw = i386_length_and_rw_bits (size, type);
|
|
|
|
|
|
|
|
|
|
if (what == WP_INSERT)
|
|
|
|
|
status = i386_insert_aligned_watchpoint (addr, len_rw);
|
|
|
|
|
else if (what == WP_REMOVE)
|
|
|
|
|
status = i386_remove_aligned_watchpoint (addr, len_rw);
|
|
|
|
|
else
|
|
|
|
|
internal_error (__FILE__, __LINE__, "\
|
|
|
|
|
Invalid value %d of operation in i386_handle_nonaligned_watchpoint.\n",
|
|
|
|
|
(int)what);
|
|
|
|
|
/* We keep the loop going even after a failure, because some
|
|
|
|
|
of the other aligned watchpoints might still succeed
|
|
|
|
|
(e.g. if they watch addresses that are already watched,
|
|
|
|
|
in which case we just increment the reference counts of
|
|
|
|
|
occupied debug registers). If we break out of the loop
|
|
|
|
|
too early, we could cause those addresses watched by
|
|
|
|
|
other watchpoints to be disabled when breakpoint.c reacts
|
|
|
|
|
to our failure to insert this watchpoint and tries to
|
|
|
|
|
remove it. */
|
|
|
|
|
if (status)
|
|
|
|
|
rv = status;
|
|
|
|
|
}
|
|
|
|
|
addr += size;
|
|
|
|
|
len -= size;
|
|
|
|
|
}
|
|
|
|
|
return rv;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
/* 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. */
|
|
|
|
|
int
|
|
|
|
|
i386_insert_watchpoint (CORE_ADDR addr, int len, int type)
|
|
|
|
|
{
|
|
|
|
|
int retval;
|
|
|
|
|
|
|
|
|
|
if (len == 3 || len > 4 || addr % len != 0)
|
|
|
|
|
retval = i386_handle_nonaligned_watchpoint (WP_INSERT, addr, len, type);
|
|
|
|
|
else
|
|
|
|
|
{
|
|
|
|
|
unsigned len_rw = i386_length_and_rw_bits (len, type);
|
|
|
|
|
|
|
|
|
|
retval = i386_insert_aligned_watchpoint (addr, len_rw);
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
if (maint_show_dr)
|
|
|
|
|
i386_show_dr ("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. Return 0 on success, -1 on failure. */
|
|
|
|
|
int
|
|
|
|
|
i386_remove_watchpoint (CORE_ADDR addr, int len, int type)
|
|
|
|
|
{
|
|
|
|
|
int retval;
|
|
|
|
|
|
|
|
|
|
if (len == 3 || len > 4 || addr % len != 0)
|
|
|
|
|
retval = i386_handle_nonaligned_watchpoint (WP_REMOVE, addr, len, type);
|
|
|
|
|
else
|
|
|
|
|
{
|
|
|
|
|
unsigned len_rw = i386_length_and_rw_bits (len, type);
|
|
|
|
|
|
|
|
|
|
retval = i386_remove_aligned_watchpoint (addr, len_rw);
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
if (maint_show_dr)
|
|
|
|
|
i386_show_dr ("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_region_ok_for_watchpoint (CORE_ADDR addr, int len)
|
|
|
|
|
{
|
|
|
|
|
/* Compute how many aligned watchpoints we would need to cover this
|
|
|
|
|
region. */
|
|
|
|
|
int nregs = i386_handle_nonaligned_watchpoint (WP_COUNT, addr, len,
|
|
|
|
|
hw_write);
|
|
|
|
|
|
|
|
|
|
return nregs <= DR_NADDR ? 1 : 0;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
/* If the inferior has some watchpoint that triggered, return the
|
|
|
|
|
address associated with that watchpoint. Otherwise, return
|
|
|
|
|
zero. */
|
|
|
|
|
CORE_ADDR
|
|
|
|
|
i386_stopped_data_address (void)
|
|
|
|
|
{
|
|
|
|
|
int i;
|
|
|
|
|
CORE_ADDR ret = 0;
|
|
|
|
|
|
|
|
|
|
dr_status_mirror = I386_DR_LOW_GET_STATUS ();
|
|
|
|
|
|
|
|
|
|
ALL_DEBUG_REGISTERS(i)
|
|
|
|
|
{
|
|
|
|
|
if (I386_DR_WATCH_HIT (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 (i) != 0)
|
|
|
|
|
{
|
|
|
|
|
ret = dr_mirror[i];
|
|
|
|
|
if (maint_show_dr)
|
|
|
|
|
i386_show_dr ("watchpoint_hit", ret, -1, hw_write);
|
|
|
|
|
}
|
|
|
|
|
}
|
|
|
|
|
if (maint_show_dr && ret == 0)
|
|
|
|
|
i386_show_dr ("stopped_data_addr", 0, 0, hw_write);
|
|
|
|
|
|
|
|
|
|
return ret;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
/* Return non-zero if the inferior has some break/watchpoint that
|
|
|
|
|
triggered. */
|
|
|
|
|
int
|
|
|
|
|
i386_stopped_by_hwbp (void)
|
|
|
|
|
{
|
|
|
|
|
int i;
|
|
|
|
|
|
|
|
|
|
dr_status_mirror = I386_DR_LOW_GET_STATUS ();
|
|
|
|
|
if (maint_show_dr)
|
|
|
|
|
i386_show_dr ("stopped_by_hwbp", 0, 0, hw_execute);
|
|
|
|
|
|
|
|
|
|
ALL_DEBUG_REGISTERS(i)
|
|
|
|
|
{
|
|
|
|
|
if (I386_DR_WATCH_HIT (i))
|
|
|
|
|
return 1;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
return 0;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
/* Insert a hardware-assisted breakpoint at address ADDR. SHADOW is
|
|
|
|
|
unused. Return 0 on success, EBUSY on failure. */
|
|
|
|
|
int
|
|
|
|
|
i386_insert_hw_breakpoint (CORE_ADDR addr, void *shadow)
|
|
|
|
|
{
|
|
|
|
|
unsigned len_rw = i386_length_and_rw_bits (1, hw_execute);
|
|
|
|
|
int retval = i386_insert_aligned_watchpoint (addr, len_rw) ? EBUSY : 0;
|
|
|
|
|
|
|
|
|
|
if (maint_show_dr)
|
|
|
|
|
i386_show_dr ("insert_hwbp", addr, 1, hw_execute);
|
|
|
|
|
|
|
|
|
|
return retval;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
/* Remove a hardware-assisted breakpoint at address ADDR. SHADOW is
|
|
|
|
|
unused. Return 0 on success, -1 on failure. */
|
|
|
|
|
int
|
|
|
|
|
i386_remove_hw_breakpoint (CORE_ADDR addr, void *shadow)
|
|
|
|
|
{
|
|
|
|
|
unsigned len_rw = i386_length_and_rw_bits (1, hw_execute);
|
|
|
|
|
int retval = i386_remove_aligned_watchpoint (addr, len_rw);
|
|
|
|
|
|
|
|
|
|
if (maint_show_dr)
|
|
|
|
|
i386_show_dr ("remove_hwbp", addr, 1, hw_execute);
|
|
|
|
|
|
|
|
|
|
return retval;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
#endif /* I386_USE_GENERIC_WATCHPOINTS */
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
void
|
|
|
|
|
_initialize_i386_nat (void)
|
|
|
|
|
{
|
|
|
|
|
#ifdef I386_USE_GENERIC_WATCHPOINTS
|
|
|
|
|
/* A maintenance command to enable printing the internal DRi mirror
|
|
|
|
|
variables. */
|
|
|
|
|
add_set_cmd ("show-debug-regs", class_maintenance,
|
|
|
|
|
var_boolean, (char *) &maint_show_dr,
|
|
|
|
|
"\
|
|
|
|
|
Set whether to show variables that mirror the x86 debug registers.\n\
|
|
|
|
|
Use \"on\" to enable, \"off\" to disable.\n\
|
|
|
|
|
If enabled, the debug registers values are shown when GDB inserts\n\
|
|
|
|
|
or removes a hardware breakpoint or watchpoint, and when the inferior\n\
|
|
|
|
|
triggers a breakpoint or watchpoint.", &maintenancelist);
|
|
|
|
|
#endif
|
|
|
|
|
}
|