3.0.x HEAD hanging

[Phil Mayers]

On 16/06/14 11:51, Phil Mayers wrote:
> We've got a version of 3.0.x HEAD running on our test server. It's
> sporadically hanging - stopping answering requests.
>
> I've caught a process doing it - backtrace here:
>
> https://gist.github.com/philmayers/5582ca9fb89f373919b5
>
> Looks like it's actually faulted, but the fault handler stuff is stuck
> on a mutex - inside talloc?

Huh, looks like backtrace() is actually calling malloc().

Oh dear:

   https://sourceware.org/bugzilla/show_bug.cgi?id=956

I'd love to say I'm surprised by the tone in the comments of that bug, 
but I've read enough glibc bugs to know that it was a common problem in 
the mid-2000s...

See however the far more reasonable and clueful:

   https://sourceware.org/bugzilla/show_bug.cgi?id=16159

Basically - backtrace() not safe to call from signal handlers by the 
looks of it? Glumness.

Still not clear why the process is SEGVing - vp->length is 3, 
talloc_array should not fail. I guess memory corruption of some sort?