Bug 40767

Could you attach the backtrace where the crash occurs?

Created attachment 51051 [details]
WoW crash dump file (text)

This is WoW's own crash file, and so probably contains far more information than you need. But it does also contain a stack trace mentioning vbo_exec_DrawRangeElements().

The backtrace doesn't show the exact line where it crashes. Can you make an apitrace record?

Created attachment 51052 [details] [review]
possible fix

Can you try this patch?

Ignore that patch, it breaks everything.

(In reply to comment #3)
> The backtrace doesn't show the exact line where it crashes. Can you make an
> apitrace record?

Dunno, what's an "apitrace record" :-)? It's probably easier to add fprintf() statements to _mesa_update_state_locked() and examine the carnage...

Apitrace can record and replay OpenGL commands. You can get it here:
https://github.com/apitrace/apitrace

There is more info in this blogpost:
http://zrusin.blogspot.com/2011/04/apitrace.html

(In reply to comment #6)
> It's probably easier to add fprintf() statements to
> _mesa_update_state_locked() and examine the carnage...

My crude debugging has revealed that the following line in update_program_enables() is reading invalid memory:

   ctx->FragmentProgram._Enabled = ctx->FragmentProgram.Enabled
      && ctx->FragmentProgram.Current->Base.Instructions;

It looks like ctx->FragmentProgram.Current is pointing to somewhere strange.

(In reply to comment #7)
> Apitrace can record and replay OpenGL commands. You can get it here:
> https://github.com/apitrace/apitrace
> 
> There is more info in this blogpost:
> http://zrusin.blogspot.com/2011/04/apitrace.html

Hmm, got any hints for how to apitrace a 32 bit executable running on a 64 bit machine under Wine, please? I've already guessed that I need a 32 bit glxtrace.so, but it's still crashing as it tries to trace wine-preloader.

Created attachment 51066 [details] [review]
possible fix 2

Can you try this patch?

(In reply to comment #10)
> Can you try this patch?

Yes, that patch seems to work. I've tried printing out the values of pc->MaxParameters, MAX_PROGRAM_LOCAL_PARAMS and MAX_PROGRAM_ENV_PARAMS, and I'm seeing lines like these:

pc->MaxParameters=4096, MAX_LOCAL=4096, MAX_ENV=256
pc->MaxParameters=96, MAX_LOCAL=4096, MAX_ENV=256

I'm guessing the first example is likely to be causing problems.

I pushed the patch. Closing.