X-Git-Url: http://drtracing.org/?a=blobdiff_plain;f=gdb%2Fmem-break.c;h=095b81f137014d526583704914df1c7e383d9b0c;hb=727605ca75e009d8468bb6378b7d18b774838b2d;hp=e2b7cbc6f35e0ed5953ff925868eda8b8f115bea;hpb=5a168c78efc6a75c33bdd11b9c8def6b3cf77212;p=deliverable%2Fbinutils-gdb.git

diff --git a/gdb/mem-break.c b/gdb/mem-break.c
index e2b7cbc6f3..095b81f137 100644
--- a/gdb/mem-break.c
+++ b/gdb/mem-break.c
@@ -1,7 +1,6 @@
 /* Simulate breakpoints by patching locations in the target system, for GDB.
 
-   Copyright 1990, 1991, 1992, 1993, 1995, 1997, 1998, 1999, 2000,
-   2002 Free Software Foundation, Inc.
+   Copyright (C) 1990-2014 Free Software Foundation, Inc.
 
    Contributed by Cygnus Support.  Written by John Gilmore.
 
@@ -9,7 +8,7 @@
 
    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
+   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,
@@ -18,75 +17,104 @@
    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.  */
+   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.  ADDR is the target
-   location in the target machine.  CONTENTS_CACHE is a pointer to 
-   memory allocated for saving the target contents.  It is guaranteed
-   by the caller to be long enough to save BREAKPOINT_LEN bytes (this
-   is accomplished via BREAKPOINT_MAX).  */
+/* 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.
+   BP_TGT->placed_address is the target location in the target
+   machine.  BP_TGT->shadow_contents is some memory allocated for
+   saving the target contents.  It is guaranteed by the caller to be
+   long enough to save BREAKPOINT_LEN bytes (this is accomplished via
+   BREAKPOINT_MAX).  */
 
 int
-default_memory_insert_breakpoint (CORE_ADDR addr, bfd_byte *contents_cache)
+default_memory_insert_breakpoint (struct gdbarch *gdbarch,
+				  struct bp_target_info *bp_tgt)
 {
   int val;
   const unsigned char *bp;
-  int bplen;
+  gdb_byte *readbuf;
 
   /* Determine appropriate breakpoint contents and size for this address.  */
-  bp = BREAKPOINT_FROM_PC (&addr, &bplen);
+  bp = gdbarch_breakpoint_from_pc
+       (gdbarch, &bp_tgt->placed_address, &bp_tgt->placed_size);
   if (bp == NULL)
     error (_("Software breakpoints not implemented for this target."));
 
-  /* Save the memory contents.  */
-  val = target_read_memory (addr, contents_cache, bplen);
-
-  /* Write the breakpoint.  */
+  /* Save the memory contents in the shadow_contents buffer and then
+     write the breakpoint instruction.  */
+  bp_tgt->shadow_len = bp_tgt->placed_size;
+  readbuf = alloca (bp_tgt->placed_size);
+  val = target_read_memory (bp_tgt->placed_address, readbuf,
+			    bp_tgt->placed_size);
   if (val == 0)
-    val = target_write_memory (addr, (char *) bp, bplen);
+    {
+      memcpy (bp_tgt->shadow_contents, readbuf, bp_tgt->placed_size);
+      val = target_write_raw_memory (bp_tgt->placed_address, bp,
+				     bp_tgt->placed_size);
+    }
 
   return val;
 }
 
 
 int
-default_memory_remove_breakpoint (CORE_ADDR addr, bfd_byte *contents_cache)
+default_memory_remove_breakpoint (struct gdbarch *gdbarch,
+				  struct bp_target_info *bp_tgt)
 {
-  const bfd_byte *bp;
-  int bplen;
+  return target_write_raw_memory (bp_tgt->placed_address, bp_tgt->shadow_contents,
+				  bp_tgt->placed_size);
+}
 
-  /* Determine appropriate breakpoint contents and size for this address.  */
-  bp = BREAKPOINT_FROM_PC (&addr, &bplen);
-  if (bp == NULL)
-    error (_("Software breakpoints not implemented for this target."));
 
-  return target_write_memory (addr, contents_cache, bplen);
+int
+memory_insert_breakpoint (struct target_ops *ops, struct gdbarch *gdbarch,
+			  struct bp_target_info *bp_tgt)
+{
+  return gdbarch_memory_insert_breakpoint (gdbarch, bp_tgt);
 }
 
-
 int
-memory_insert_breakpoint (CORE_ADDR addr, bfd_byte *contents_cache)
+memory_remove_breakpoint (struct target_ops *ops, struct gdbarch *gdbarch,
+			  struct bp_target_info *bp_tgt)
 {
-  return MEMORY_INSERT_BREAKPOINT(addr, contents_cache);
+  return gdbarch_memory_remove_breakpoint (gdbarch, bp_tgt);
 }
 
 int
-memory_remove_breakpoint (CORE_ADDR addr, bfd_byte *contents_cache)
+memory_validate_breakpoint (struct gdbarch *gdbarch,
+			    struct bp_target_info *bp_tgt)
 {
-  return MEMORY_REMOVE_BREAKPOINT(addr, contents_cache);
+  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;
 }