/* Simulate breakpoints by patching locations in the target system, for GDB.
- Copyright (C) 1990, 1991, 1992, 1993, 1995, 1997, 1998, 1999, 2000, 2002,
- 2007, 2008, 2009 Free Software Foundation, Inc.
+ Copyright (C) 1990-2015 Free Software Foundation, Inc.
Contributed by Cygnus Support. Written by John Gilmore.
along with this program. If not, see <http://www.gnu.org/licenses/>. */
#include "defs.h"
-
-/* This file is only useful if BREAKPOINT_FROM_PC is set. If not, we
- punt. */
-
#include "symtab.h"
#include "breakpoint.h"
#include "inferior.h"
#include "target.h"
-
-
/* Insert a breakpoint on targets that don't have any better
breakpoint support. We read the contents of the target location
and stash it, then overwrite it with a breakpoint instruction.
default_memory_insert_breakpoint (struct gdbarch *gdbarch,
struct bp_target_info *bp_tgt)
{
- int val;
+ CORE_ADDR addr = bp_tgt->reqstd_address;
const unsigned char *bp;
+ gdb_byte *readbuf;
int bplen;
+ int val;
/* Determine appropriate breakpoint contents and size for this address. */
- bp = gdbarch_breakpoint_from_pc
- (gdbarch, &bp_tgt->placed_address, &bp_tgt->placed_size);
+ bp = gdbarch_breakpoint_from_pc (gdbarch, &addr, &bplen);
if (bp == NULL)
error (_("Software breakpoints not implemented for this target."));
- /* Save the memory contents. */
- bp_tgt->shadow_len = bp_tgt->placed_size;
- val = target_read_memory (bp_tgt->placed_address, bp_tgt->shadow_contents,
- bp_tgt->placed_size);
+ bp_tgt->placed_address = addr;
+ bp_tgt->placed_size = bplen;
- /* Write the breakpoint. */
+ /* Save the memory contents in the shadow_contents buffer and then
+ write the breakpoint instruction. */
+ readbuf = (gdb_byte *) alloca (bplen);
+ val = target_read_memory (addr, readbuf, bplen);
if (val == 0)
- val = target_write_memory (bp_tgt->placed_address, bp,
- bp_tgt->placed_size);
+ {
+ /* These must be set together, either before or after the shadow
+ read, so that if we're "reinserting" a breakpoint that
+ doesn't have a shadow yet, the breakpoint masking code inside
+ target_read_memory doesn't mask out this breakpoint using an
+ unfilled shadow buffer. The core may be trying to reinsert a
+ permanent breakpoint, for targets that support breakpoint
+ conditions/commands on the target side for some types of
+ breakpoints, such as target remote. */
+ bp_tgt->shadow_len = bplen;
+ memcpy (bp_tgt->shadow_contents, readbuf, bplen);
+
+ val = target_write_raw_memory (addr, bp, bplen);
+ }
return val;
}
default_memory_remove_breakpoint (struct gdbarch *gdbarch,
struct bp_target_info *bp_tgt)
{
- return target_write_memory (bp_tgt->placed_address, bp_tgt->shadow_contents,
- bp_tgt->placed_size);
+ return target_write_raw_memory (bp_tgt->placed_address, bp_tgt->shadow_contents,
+ bp_tgt->placed_size);
}
int
-memory_insert_breakpoint (struct bp_target_info *bp_tgt)
+memory_insert_breakpoint (struct target_ops *ops, struct gdbarch *gdbarch,
+ struct bp_target_info *bp_tgt)
{
- return gdbarch_memory_insert_breakpoint (current_gdbarch, bp_tgt);
+ return gdbarch_memory_insert_breakpoint (gdbarch, bp_tgt);
}
int
-memory_remove_breakpoint (struct bp_target_info *bp_tgt)
+memory_remove_breakpoint (struct target_ops *ops, struct gdbarch *gdbarch,
+ struct bp_target_info *bp_tgt)
{
- return gdbarch_memory_remove_breakpoint (current_gdbarch, bp_tgt);
+ return gdbarch_memory_remove_breakpoint (gdbarch, bp_tgt);
+}
+
+int
+memory_validate_breakpoint (struct gdbarch *gdbarch,
+ struct bp_target_info *bp_tgt)
+{
+ CORE_ADDR addr = bp_tgt->placed_address;
+ const gdb_byte *bp;
+ int val;
+ int bplen;
+ gdb_byte cur_contents[BREAKPOINT_MAX];
+ struct cleanup *cleanup;
+ int ret;
+
+ /* Determine appropriate breakpoint contents and size for this
+ address. */
+ bp = gdbarch_breakpoint_from_pc (gdbarch, &addr, &bplen);
+
+ if (bp == NULL || bp_tgt->placed_size != bplen)
+ return 0;
+
+ /* Make sure we see the memory breakpoints. */
+ cleanup = make_show_memory_breakpoints_cleanup (1);
+ val = target_read_memory (addr, cur_contents, bplen);
+
+ /* If our breakpoint is no longer at the address, this means that
+ the program modified the code on us, so it is wrong to put back
+ the old value. */
+ ret = (val == 0 && memcmp (bp, cur_contents, bplen) == 0);
+
+ do_cleanups (cleanup);
+ return ret;
}