X-Git-Url: http://git.efficios.com/?a=blobdiff_plain;f=gdb%2Fmem-break.c;h=a251aa4337251c45687cba366b06fbc42b4082b5;hb=f4ec508eaed65ad7555858498c1cbbf420bce90a;hp=60a41e8db5db7f12f9e8fcd5caec52a35204fe1d;hpb=a9762ec78a53fbe9209fe1654db42df0cd328d50;p=deliverable%2Fbinutils-gdb.git

diff --git a/gdb/mem-break.c b/gdb/mem-break.c
index 60a41e8db5..a251aa4337 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 (C) 1990, 1991, 1992, 1993, 1995, 1997, 1998, 1999, 2000, 2002,
-   2007 Free Software Foundation, Inc.
+   Copyright (C) 1990-2020 Free Software Foundation, Inc.
 
    Contributed by Cygnus Support.  Written by John Gilmore.
 
@@ -21,15 +20,11 @@
    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"
-
+#include "gdbarch.h"
 
 /* Insert a breakpoint on targets that don't have any better
    breakpoint support.  We read the contents of the target location
@@ -41,48 +36,94 @@
    BREAKPOINT_MAX).  */
 
 int
-default_memory_insert_breakpoint (struct bp_target_info *bp_tgt)
+default_memory_insert_breakpoint (struct gdbarch *gdbarch,
+				  struct bp_target_info *bp_tgt)
 {
-  int val;
+  CORE_ADDR addr = bp_tgt->placed_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
-       (current_gdbarch, &bp_tgt->placed_address, &bp_tgt->placed_size);
-  if (bp == NULL)
-    error (_("Software breakpoints not implemented for this target."));
+  bp = gdbarch_sw_breakpoint_from_kind (gdbarch, bp_tgt->kind, &bplen);
 
-  /* 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);
-
-  /* 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;
 }
 
 
 int
-default_memory_remove_breakpoint (struct bp_target_info *bp_tgt)
+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);
+  int bplen;
+
+  gdbarch_sw_breakpoint_from_kind (gdbarch, bp_tgt->kind, &bplen);
+
+  return target_write_raw_memory (bp_tgt->placed_address, bp_tgt->shadow_contents,
+				  bplen);
 }
 
 
 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,
+			  enum remove_bp_reason reason)
 {
-  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];
+
+  /* Determine appropriate breakpoint contents and size for this
+     address.  */
+  bp = gdbarch_breakpoint_from_pc (gdbarch, &addr, &bplen);
+
+  if (bp == NULL)
+    return 0;
+
+  /* Make sure we see the memory breakpoints.  */
+  scoped_restore restore_memory
+    = make_scoped_restore_show_memory_breakpoints (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.  */
+  return (val == 0 && memcmp (bp, cur_contents, bplen) == 0);
 }