Re: [RFA] Resubmit reverse debugging [5/5]

[Michael Snyder <msnyder@vmware.com>]

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Thiago Jung Bauermann wrote:
> El mar, 07-10-2008 a las 19:20 -0700, Michael Snyder escribió:
>> +static void
>> +exec_reverse_once (char *cmd, char *args, int from_tty)
>> +{
>> +  /* String buffer for command consing.  */
>> +  char reverse_command[512];
> <snip>
>> +  sprintf (reverse_command, "%s %s", cmd, args ? args : "");
>> +
>> +  execution_direction = EXEC_REVERSE;
>> +  execute_command (reverse_command, from_tty);
>> +  do_cleanups (old_chain);
> 
> That fixed-length buffer being written with sprintf doesn't look good...
> What do you think about using xstrprintf instead? That will remove the
> possibility of buffer overflow, and also remove an arbitrary limit.

How about this?  (the function pointer idea I leave for a future 
enhancement):


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Index: reverse.c
===================================================================
RCS file: /cvs/src/src/gdb/Attic/reverse.c,v
retrieving revision 1.1.10.6
diff -u -p -r1.1.10.6 reverse.c
--- reverse.c	8 Oct 2008 00:26:28 -0000	1.1.10.6
+++ reverse.c	8 Oct 2008 21:03:59 -0000
@@ -44,8 +44,7 @@ static void exec_direction_default (void
 static void
 exec_reverse_once (char *cmd, char *args, int from_tty)
 {
-  /* String buffer for command consing.  */
-  char reverse_command[512];
+  char *reverse_command;
   enum exec_direction_kind dir = execution_direction;
   struct cleanup *old_chain;
 
@@ -59,9 +58,9 @@ exec_reverse_once (char *cmd, char *args
   if (!target_can_execute_reverse)
     error (_("Target %s does not support this command."), target_shortname);
 
+  reverse_command = xstrprintf ("%s %s", cmd, args ? args : "");
   old_chain = make_cleanup (exec_direction_default, NULL);
-  sprintf (reverse_command, "%s %s", cmd, args ? args : "");
-
+  make_cleanup (xfree, reverse_command);
   execution_direction = EXEC_REVERSE;
   execute_command (reverse_command, from_tty);
   do_cleanups (old_chain);