1998-12-03 Jason Molenda (jsm@bugshack.cygnus.com)

        * monitor.c (monitor_read_memory): Zero out pattern buffers
        before calling re_search.
        (parse_register_dump): Ditto.

PR 18049.  This bug had existed erratically since I upgraded to
the new gnu-regex.c this last summer.  The problem is mostly in
parse_register_dump; the allocated structure has some random values
in it and there is a flag set in the register_pattern structure by the
gnu-regex library which indicates that the values in the re_registers
should be trusted.

If those arbitrary contents aren't zero, gnu-regex tries to run realloc
on them and we get a core dump on some hosts for some targets when the
moon is just right.

1 files changed, 3 insertions, 0 deletions

diff --git a/gdb/monitor.c b/gdb/monitor.c
index 60cfc143e71..ddd24c25a94 100644
--- a/gdb/monitor.c
+++ b/gdb/monitor.c
@@ -847,6 +847,8 @@ parse_register_dump (buf, len)
 	 points to the start of the register value.  */
       struct re_registers register_strings;
 
+      memset (&register_strings, 0, sizeof (struct re_registers));
+
       if (re_search (&register_pattern, buf, len, 0, len,
 		     &register_strings) == -1)
 	break;
@@ -1759,6 +1761,7 @@ monitor_read_memory (memaddr, myaddr, len)
       struct re_registers resp_strings;
       RDEBUG(("MON getmem.resp_delim %s\n",current_monitor->getmem.resp_delim)) ;
 
+      memset (&resp_strings, 0, sizeof (struct re_registers));
       tmp = strlen (p);
       retval = re_search (&getmem_resp_delim_pattern, p, tmp, 0, tmp,
 			  &resp_strings);