2d97cd356e
Without this patch, when doing a software single step, with for example
a conditional breakpoint, gdbserver would wrongly avance the pc of
breakpoint_len and skips an instruction.
This is due to gdbserver assuming that it's hardware single stepping.
When it resumes from the breakpoint address it expects the trap to be
caused by ptrace and if it's rather caused by a software breakpoint
it assumes this is a permanent breakpoint and that it needs to skip
over it.
However when software single stepping, this breakpoint is legitimate as
it's the reinsert breakpoint gdbserver has put in place to break at
the next instruction. Thus gdbserver wrongly advances the pc and skips
an instruction.
This patch fixes this behavior so that gdbserver checks if it is a
reinsert breakpoint from software single stepping. If it is it won't
advance the pc. And if there's no reinsert breakpoint there we assume
then that it's a permanent breakpoint and advance the pc.
Here's a commented log of what would happen before and after the fix on
gdbserver :
/* Here there is a conditional breakpoint at 0x10428 that needs to be
stepped over. */
Need step over [LWP 11204]? yes, found breakpoint at 0x10428
...
/* e7f001f0 is a breakpoint instruction on arm
Here gdbserver writes the software breakpoint we would like to hit
*/
Writing e7f001f0 to 0x0001042c in process 11204
...
Resuming lwp 11220 (continue, signal 0, stop not expected)
pending reinsert at 0x10428
stop pc is 00010428
continue from pc 0x10428
...
/* Here gdbserver hit the software breakpoint that was in place
for the step over */
stop pc is 0001042c
pc is 0x1042c
step-over for LWP 11220.11220 executed software breakpoint
Finished step over.
Could not find fast tracepoint jump at 0x10428 in list (reinserting).
/* Here gdbserver writes back the original instruction */
Writing e50b3008 to 0x0001042c in process 11220
Step-over finished.
Need step over [LWP 11220]? No
/* Here because gdbserver assumes this is a permenant breakpoint it advances
the pc of breakpoint_len, in this case 4 bytes, so we have just skipped
the instruction that was written back here :
Writing e50b3008 to 0x0001042c in process 11220
*/
stop pc is 00010430
pc is 0x10430
Need step over [LWP 11220]? No, no breakpoint found at 0x10430
Proceeding, no step-over needed
proceed_one_lwp: lwp 11220
stop pc is 00010430
This patch fixes this situation and we get the right behavior :
Writing e50b3008 to 0x0001042c in process 11245
Hit a gdbserver breakpoint.
Hit a gdbserver breakpoint.
Step-over finished.
proceeding all threads.
Need step over [LWP 11245]? No
stop pc is 0001042c
pc is 0x1042c
Need step over [LWP 11245]? No, no breakpoint found at 0x1042c
Proceeding, no step-over needed
proceed_one_lwp: lwp 11245
stop pc is 0001042c
pc is 0x1042c
Resuming lwp 11245 (continue, signal 0, stop not expected)
stop pc is 0001042c
continue from pc 0x1042c
It also works if the value at 0x0001042c is a permanent breakpoint.
If so gdbserver will finish the step over, remove the reinserted breakpoint,
resume at that location and on the next SIGTRAP gdbserver will trigger
the advance PC condition as reinsert_breakpoint_inserted_here will be false.
I also tested this against bp-permanent.exp on arm (with a work in progress
software single step patchset) without any regressions.
It's also tested against x86 bp-permanent.exp without any regression.
So both software and hardware single step are tested.
No regressions on Ubuntu 14.04 on ARMv7 and x86.
With gdbserver-{native,extended} / { -marm -mthumb }
gdb/gdbserver/ChangeLog:
* linux-low.c (linux_wait_1): Fix pc advance condition.
* mem-break.c (reinsert_breakpoint_inserted_here): New function.
* mem-break.h (reinsert_breakpoint_inserted_here): New declaration.
261 lines
8 KiB
C
261 lines
8 KiB
C
/* Memory breakpoint interfaces for the remote server for GDB.
|
|
Copyright (C) 2002-2015 Free Software Foundation, Inc.
|
|
|
|
Contributed by MontaVista Software.
|
|
|
|
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/>. */
|
|
|
|
#ifndef MEM_BREAK_H
|
|
#define MEM_BREAK_H
|
|
|
|
#include "break-common.h"
|
|
|
|
/* Breakpoints are opaque. */
|
|
struct breakpoint;
|
|
struct fast_tracepoint_jump;
|
|
struct raw_breakpoint;
|
|
struct process_info;
|
|
|
|
#define Z_PACKET_SW_BP '0'
|
|
#define Z_PACKET_HW_BP '1'
|
|
#define Z_PACKET_WRITE_WP '2'
|
|
#define Z_PACKET_READ_WP '3'
|
|
#define Z_PACKET_ACCESS_WP '4'
|
|
|
|
/* The low level breakpoint types. */
|
|
|
|
enum raw_bkpt_type
|
|
{
|
|
/* Software/memory breakpoint. */
|
|
raw_bkpt_type_sw,
|
|
|
|
/* Hardware-assisted breakpoint. */
|
|
raw_bkpt_type_hw,
|
|
|
|
/* Hardware-assisted write watchpoint. */
|
|
raw_bkpt_type_write_wp,
|
|
|
|
/* Hardware-assisted read watchpoint. */
|
|
raw_bkpt_type_read_wp,
|
|
|
|
/* Hardware-assisted access watchpoint. */
|
|
raw_bkpt_type_access_wp
|
|
};
|
|
|
|
/* Map the protocol breakpoint/watchpoint type Z_TYPE to the internal
|
|
raw breakpoint type. */
|
|
|
|
enum raw_bkpt_type Z_packet_to_raw_bkpt_type (char z_type);
|
|
|
|
/* Map a raw breakpoint type to an enum target_hw_bp_type. */
|
|
|
|
enum target_hw_bp_type raw_bkpt_type_to_target_hw_bp_type
|
|
(enum raw_bkpt_type raw_type);
|
|
|
|
/* Create a new GDB breakpoint of type Z_TYPE at ADDR with kind KIND.
|
|
Returns a pointer to the newly created breakpoint on success. On
|
|
failure returns NULL and sets *ERR to either -1 for error, or 1 if
|
|
Z_TYPE breakpoints are not supported on this target. */
|
|
|
|
struct breakpoint *set_gdb_breakpoint (char z_type, CORE_ADDR addr, int kind,
|
|
int *err);
|
|
|
|
/* Delete a GDB breakpoint of type Z_TYPE and kind KIND previously
|
|
inserted at ADDR with set_gdb_breakpoint_at. Returns 0 on success,
|
|
-1 on error, and 1 if Z_TYPE breakpoints are not supported on this
|
|
target. */
|
|
|
|
int delete_gdb_breakpoint (char z_type, CORE_ADDR addr, int kind);
|
|
|
|
/* Returns TRUE if there's a software or hardware (code) breakpoint at
|
|
ADDR in our tables, inserted, or not. */
|
|
|
|
int breakpoint_here (CORE_ADDR addr);
|
|
|
|
/* Returns TRUE if there's any inserted software or hardware (code)
|
|
breakpoint set at ADDR. */
|
|
|
|
int breakpoint_inserted_here (CORE_ADDR addr);
|
|
|
|
/* Returns TRUE if there's any inserted software breakpoint at
|
|
ADDR. */
|
|
|
|
int software_breakpoint_inserted_here (CORE_ADDR addr);
|
|
|
|
/* Returns TRUE if there's any inserted hardware (code) breakpoint at
|
|
ADDR. */
|
|
|
|
int hardware_breakpoint_inserted_here (CORE_ADDR addr);
|
|
|
|
/* Returns TRUE if there's any reinsert breakpoint at ADDR. */
|
|
|
|
int reinsert_breakpoint_inserted_here (CORE_ADDR addr);
|
|
|
|
/* Clear all breakpoint conditions and commands associated with a
|
|
breakpoint. */
|
|
|
|
void clear_breakpoint_conditions_and_commands (struct breakpoint *bp);
|
|
|
|
/* Set target-side condition CONDITION to the breakpoint at ADDR.
|
|
Returns false on failure. On success, advances CONDITION pointer
|
|
past the condition and returns true. */
|
|
|
|
int add_breakpoint_condition (struct breakpoint *bp, char **condition);
|
|
|
|
/* Set target-side commands COMMANDS to the breakpoint at ADDR.
|
|
Returns false on failure. On success, advances COMMANDS past the
|
|
commands and returns true. If PERSIST, the commands should run
|
|
even while GDB is disconnected. */
|
|
|
|
int add_breakpoint_commands (struct breakpoint *bp, char **commands,
|
|
int persist);
|
|
|
|
int any_persistent_commands (void);
|
|
|
|
/* Evaluation condition (if any) at breakpoint BP. Return 1 if
|
|
true and 0 otherwise. */
|
|
|
|
int gdb_condition_true_at_breakpoint (CORE_ADDR where);
|
|
|
|
int gdb_no_commands_at_breakpoint (CORE_ADDR where);
|
|
|
|
void run_breakpoint_commands (CORE_ADDR where);
|
|
|
|
/* Returns TRUE if there's a GDB breakpoint (Z0 or Z1) set at
|
|
WHERE. */
|
|
|
|
int gdb_breakpoint_here (CORE_ADDR where);
|
|
|
|
/* Create a new breakpoint at WHERE, and call HANDLER when
|
|
it is hit. HANDLER should return 1 if the breakpoint
|
|
should be deleted, 0 otherwise. */
|
|
|
|
struct breakpoint *set_breakpoint_at (CORE_ADDR where,
|
|
int (*handler) (CORE_ADDR));
|
|
|
|
/* Delete a breakpoint. */
|
|
|
|
int delete_breakpoint (struct breakpoint *bkpt);
|
|
|
|
/* Set a reinsert breakpoint at STOP_AT. */
|
|
|
|
void set_reinsert_breakpoint (CORE_ADDR stop_at);
|
|
|
|
/* Delete all reinsert breakpoints. */
|
|
|
|
void delete_reinsert_breakpoints (void);
|
|
|
|
/* Reinsert breakpoints at WHERE (and change their status to
|
|
inserted). */
|
|
|
|
void reinsert_breakpoints_at (CORE_ADDR where);
|
|
|
|
/* Uninsert breakpoints at WHERE (and change their status to
|
|
uninserted). This still leaves the breakpoints in the table. */
|
|
|
|
void uninsert_breakpoints_at (CORE_ADDR where);
|
|
|
|
/* Reinsert all breakpoints of the current process (and change their
|
|
status to inserted). */
|
|
|
|
void reinsert_all_breakpoints (void);
|
|
|
|
/* Uninsert all breakpoints of the current process (and change their
|
|
status to uninserted). This still leaves the breakpoints in the
|
|
table. */
|
|
|
|
void uninsert_all_breakpoints (void);
|
|
|
|
/* See if any breakpoint claims ownership of STOP_PC. Call the handler for
|
|
the breakpoint, if found. */
|
|
|
|
void check_breakpoints (CORE_ADDR stop_pc);
|
|
|
|
/* See if any breakpoints shadow the target memory area from MEM_ADDR
|
|
to MEM_ADDR + MEM_LEN. Update the data already read from the target
|
|
(in BUF) if necessary. */
|
|
|
|
void check_mem_read (CORE_ADDR mem_addr, unsigned char *buf, int mem_len);
|
|
|
|
/* See if any breakpoints shadow the target memory area from MEM_ADDR
|
|
to MEM_ADDR + MEM_LEN. Update the data to be written to the target
|
|
(in BUF, a copy of MYADDR on entry) if necessary, as well as the
|
|
original data for any breakpoints. */
|
|
|
|
void check_mem_write (CORE_ADDR mem_addr,
|
|
unsigned char *buf, const unsigned char *myaddr, int mem_len);
|
|
|
|
/* Delete all breakpoints. */
|
|
|
|
void delete_all_breakpoints (void);
|
|
|
|
/* Clear the "inserted" flag in all breakpoints of PROC. */
|
|
|
|
void mark_breakpoints_out (struct process_info *proc);
|
|
|
|
/* Delete all breakpoints, but do not try to un-insert them from the
|
|
inferior. */
|
|
|
|
void free_all_breakpoints (struct process_info *proc);
|
|
|
|
/* Check if breakpoints still seem to be inserted in the inferior. */
|
|
|
|
void validate_breakpoints (void);
|
|
|
|
/* Insert a fast tracepoint jump at WHERE, using instruction INSN, of
|
|
LENGTH bytes. */
|
|
|
|
struct fast_tracepoint_jump *set_fast_tracepoint_jump (CORE_ADDR where,
|
|
unsigned char *insn,
|
|
ULONGEST length);
|
|
|
|
/* Increment reference counter of JP. */
|
|
void inc_ref_fast_tracepoint_jump (struct fast_tracepoint_jump *jp);
|
|
|
|
/* Delete fast tracepoint jump TODEL from our tables, and uninsert if
|
|
from memory. */
|
|
|
|
int delete_fast_tracepoint_jump (struct fast_tracepoint_jump *todel);
|
|
|
|
/* Returns true if there's fast tracepoint jump set at WHERE. */
|
|
|
|
int fast_tracepoint_jump_here (CORE_ADDR);
|
|
|
|
/* Uninsert fast tracepoint jumps at WHERE (and change their status to
|
|
uninserted). This still leaves the tracepoints in the table. */
|
|
|
|
void uninsert_fast_tracepoint_jumps_at (CORE_ADDR pc);
|
|
|
|
/* Reinsert fast tracepoint jumps at WHERE (and change their status to
|
|
inserted). */
|
|
|
|
void reinsert_fast_tracepoint_jumps_at (CORE_ADDR where);
|
|
|
|
/* Insert a memory breakpoint. */
|
|
|
|
int insert_memory_breakpoint (struct raw_breakpoint *bp);
|
|
|
|
/* Remove a previously inserted memory breakpoint. */
|
|
|
|
int remove_memory_breakpoint (struct raw_breakpoint *bp);
|
|
|
|
/* Create a new breakpoint list NEW_BKPT_LIST that is a copy of SRC. */
|
|
|
|
void clone_all_breakpoints (struct breakpoint **new_bkpt_list,
|
|
struct raw_breakpoint **new_raw_bkpt_list,
|
|
const struct breakpoint *src);
|
|
|
|
#endif /* MEM_BREAK_H */
|