[PATCH/7.6] Fix wrong release (maybe crash GDB) in build_target_command_list

Hui Zhu
2013-04-24T13:30:12Z

Hi,

I found this bug when I try to fix 15180.
In function build_target_command_list:
When it try to release the loc->cmd_bytecode in the first loop, it try
to release loc->cond_bytecode:
/* If anything failed, then we're not doing target-side commands,
and so clean up. */
if (null_command_or_parse_error)
{
ALL_BP_LOCATIONS_AT_ADDR (loc2p, locp, bl->address)
{
loc = (*loc2p);
if (is_breakpoint (loc->owner)
&& loc->pspace->num == bl->pspace->num)
{
/* Only go as far as the first NULL bytecode is
located. */
if (!loc->cond_bytecode)
return;

free_agent_expr (loc->cond_bytecode);
loc->cond_bytecode = NULL;
}
}
}

I think it will crash GDB something. So I suggest fix it before 7.6 release.

Thanks,
Hui

2013-04-24 Hui Zhu <hui@codesourcery.com>

* breakpoint.c (build_target_command_list): Change loc->cond_bytecode
to loc->cmd_bytecode.

--- a/gdb/breakpoint.c
+++ b/gdb/breakpoint.c
@@ -2343,11 +2343,11 @@ build_target_command_list (struct bp_loc
{
/* Only go as far as the first NULL bytecode is
located. */
- if (!loc->cond_bytecode)
+ if (!loc->cmd_bytecode)
return;

- free_agent_expr (loc->cond_bytecode);
- loc->cond_bytecode = NULL;
+ free_agent_expr (loc->cmd_bytecode);
+ loc->cmd_bytecode = NULL;
}
}
}