Re: [PATCH] Fix tracepoint create_tsv_from_upload sprintf crash

[Hui Zhu <teawater at gmail dot com>]

On Wed, Dec 7, 2011 at 00:00, Hui Zhu <teawater@gmail.com> wrote:
> On Tue, Dec 6, 2011 at 23:43, Tom Tromey <tromey@redhat.com> wrote:
>>>>>>> ">" == Hui Zhu <teawater@gmail.com> writes:
>>
>>>> 2011-12-06 ?Hui Zhu ?<teawater@gmail.com>
>>>> ? ? ?* tracepoint.c (create_tsv_from_upload): Change sprintf to snprintf.
>>
>> How about using xstrprintf instead?
>> Then the name can be as long as you like.
>>
>> Tom
>
> Cool! I like it. ?I will make a patch according to your mail later.
>
> Thanks for your help.
>
> Best,
> Hui

Hi Tom,

I make a new patch according to your comments.

Please help me review it.

Thanks,
Hui

2011-12-08  Hui Zhu  <teawater@gmail.com>

	* tracepoint.c (create_tsv_from_upload): Change sprintf to xstrprintf.
---
 tracepoint.c |   16 ++++++++++++----
 1 file changed, 12 insertions(+), 4 deletions(-)

--- a/tracepoint.c
+++ b/tracepoint.c
@@ -3482,31 +3482,39 @@ struct trace_state_variable *
 create_tsv_from_upload (struct uploaded_tsv *utsv)
 {
   const char *namebase;
-  char buf[20];
+  char *buf;
   int try_num = 0;
   struct trace_state_variable *tsv;
+  struct cleanup *old_chain;

   if (utsv->name)
     {
       namebase = utsv->name;
-      sprintf (buf, "%s", namebase);
+      buf = xstrprintf ("%s", namebase);
     }
   else
     {
       namebase = "__tsv";
-      sprintf (buf, "%s_%d", namebase, try_num++);
+      buf = xstrprintf ("%s_%d", namebase, try_num++);
     }

   /* Fish for a name that is not in use.  */
   /* (should check against all internal vars?)  */
   while (find_trace_state_variable (buf))
-    sprintf (buf, "%s_%d", namebase, try_num++);
+    {
+      xfree (buf);
+      buf = xstrprintf ("%s_%d", namebase, try_num++);
+    }
+
+  old_chain = make_cleanup (xfree, buf);

   /* We have an available name, create the variable.  */
   tsv = create_trace_state_variable (buf);
   tsv->initial_value = utsv->initial_value;
   tsv->builtin = utsv->builtin;

+  do_cleanups (old_chain);
+
   return tsv;
 }