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Summary:ASTERISK-10137: Asterisk crashed in function ast_dynamic_str_thread_build_va in utils.c
Reporter:Jon Creasy (johann8384)Labels:
Date Opened:2007-08-21 20:42:03Date Closed:2007-08-23 12:05:17
Priority:CriticalRegression?No
Status:Closed/CompleteComponents:Addons/General
Versions:Frequency of
Occurrence
Related
Issues:
Environment:Attachments:( 0) output_better.txt
Description:
johann8384 - reporter
08-21-07 20:28

I know it will be obvious to you when you look at this but I'm trying to learn a little bit as I go along so hopefully I'll be fixing stuff myself before long.

To me the problem looks like it's crashing trying to print to the return value of a vsnprintf to an int res in ast_dynamic_str_thread_build_va.

The message is "Variable 'res' is not available". My C is weak, that is line 1200, line 1194 is "int res;".

3 0x080fbf87 in ast_dynamic_str_thread_build_va (buf=0xb7e7233c, max_len=8192, ts=0x825cd60, append=0,
   fmt=0x281380 "MySQL RealTime: Database Select Failed (%d): %s\n", ap=0xb7e74664 "S%(") at utils.c:1200
       res = Variable "res" is not available.

/*!
* core handler for dynamic strings.
* This is not meant to be called directly, but rather through the
* various wrapper macros
* ast_str_set(...)
* ast_str_append(...)
* ast_str_set_va(...)
* ast_str_append_va(...)
*/
int __ast_str_helper(struct ast_str **buf, size_t max_len,
   int append, const char *fmt, va_list ap)
{
   int res, need;
   int offset = (append && (*buf)->len) ? (*buf)->used : 0;

   if (max_len < 0)
       max_len = (*buf)->len; /* don't exceed the allocated space */
   /*
    * Ask vsnprintf how much space we need. Remember that vsnprintf
    * does not count the final '\0' so we must add 1.
    */
   res = vsnprintf((*buf)->str + offset, (*buf)->len - offset, fmt, ap);

   need = res + offset + 1;
   /*
    * If there is not enough space and we are below the max length,
    * reallocate the buffer and return a message telling to retry.
    */
   if (need > (*buf)->len && (max_len == 0 || (*buf)->len < max_len) ) {
       if (max_len && max_len < need) /* truncate as needed */
           need = max_len;
       else if (max_len == 0) /* if unbounded, give more room for next time */
           need += 16 + need/4;
       if (0) /* debugging */
           ast_verbose("extend from %d to %d\n", (int)(*buf)->len, need);
       if (ast_str_make_space(buf, need)) {
           ast_verbose("failed to extend from %d to %d\n", (int)(*buf)->len, need);
           return AST_DYNSTR_BUILD_FAILED;
       }
       (*buf)->str[offset] = '\0'; /* Truncate the partial write. */

       /* va_end() and va_start() must be done before calling
        * vsnprintf() again. */
       return AST_DYNSTR_BUILD_RETRY;
   }
   /* update space used, keep in mind the truncation */
   (*buf)->used = (res + offset > (*buf)->len) ? (*buf)->len : res + offset;

   return res;
}

****** ADDITIONAL INFORMATION ******

I also mentioned this while trying to debug another problem in 10348 but I don't think this has anything to do with that (I realized later) so I'm posting here in case this is something.
Comments:By: Digium Subversion (svnbot) 2007-08-23 12:03:42

Repository: asterisk-addons
Revision: 428

------------------------------------------------------------------------
r428 | russell | 2007-08-23 12:03:42 -0500 (Thu, 23 Aug 2007) | 4 lines

Fix a format string error that caused a crash.  This debug message tried to
print something as string that was just an int.
(closes issue ASTERISK-10137, reported by johann8384, patch by me)

------------------------------------------------------------------------
By: Digium Subversion (svnbot) 2007-08-23 12:05:17

Repository: asterisk-addons
Revision: 429

------------------------------------------------------------------------
r429 | russell | 2007-08-23 12:05:17 -0500 (Thu, 23 Aug 2007) | 12 lines

Merged revisions 428 via svnmerge from
https://origsvn.digium.com/svn/asterisk-addons/branches/1.4

........
r428 | russell | 2007-08-23 12:21:44 -0500 (Thu, 23 Aug 2007) | 4 lines

Fix a format string error that caused a crash.  This debug message tried to
print something as string that was just an int.
(closes issue ASTERISK-10137, reported by johann8384, patch by me)

........

------------------------------------------------------------------------