Bug 362009 - Valgrind dumps core on unimplemented functionality before threads are created
Summary: Valgrind dumps core on unimplemented functionality before threads are created
Status: RESOLVED FIXED
Alias: None
Product: valgrind
Classification: Developer tools
Component: general (show other bugs)
Version: 3.12 SVN
Platform: Compiled Sources Solaris
: NOR minor
Target Milestone: ---
Assignee: Ivo Raisr
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2016-04-20 18:05 UTC by Ivo Raisr
Modified: 2016-04-23 19:35 UTC (History)
2 users (show)

See Also:
Latest Commit: 15867
Version Fixed In:
Sentry Crash Report:

Attachments
proposed patch (5.79 KB, patch)
2016-04-20 18:11 UTC, Ivo Raisr 		Details
proposed patch v2 (5.73 KB, patch)
2016-04-21 04:49 UTC, Ivo Raisr 		Details
Show Obsolete (1) View All Add an attachment

Note You need to log in before you can comment on or make changes to this bug.
Description Ivo Raisr 2016-04-20 18:05:24 UTC 
If VG_(unimplemented)() is called early during the main initialization, before the threads are created,
Valgrind dumps core in show_sched_status_wrk().
That's because VG_(threads) is still NULL and it is dereferenced via VG_(threads)[i].os_state...

This happens for example on Solaris when VG_(unimplemented)() is called from VG_(load_ELF)() which is used during client image initialization.

Fix attached, regression testing went fine.
Comment 1 Ivo Raisr 2016-04-20 18:11:15 UTC 
Created attachment 98481 [details]
proposed patch

The patch consists mainly of whitespace changes due to different indentation.
Comment 2 Philippe Waroquiers 2016-04-20 20:10:34 UTC 
If show sched status is called before the threads are implemented, then nothing will be
visible.
Maybe it would be better to do something like:

   if (VG_(threads) == NULL) {
      VG_(printf) ("cannot show sched status : scheduler not yet initialised\");
      return;
  }
  ... here the old code ...
rather than report nothing ?
Comment 3 Ivo Raisr 2016-04-21 04:49:48 UTC 
Created attachment 98489 [details]
proposed patch v2

Addresses Philippe's comment.
Comment 4 Ivo Raisr 2016-04-21 04:50:21 UTC 
You are right, Philippe, that's very good remark.
I have attached new patch.
Comment 5 Ivo Raisr 2016-04-23 19:35:35 UTC 
Fixed in SVN r15867.