compiz crashed with SIGSEGV in nux::GraphicsDisplay::GetGpuDevice()

[Helge Jung]

Out of nowhere the desktop froze and after the current song Banshee also stopped playing. Switching on a text console htop revealed a high system load. I killed opera and as that didn't help I issued a "unity --replace" - after a couple of seconds, the system came back.

ProblemType: Crash
DistroRelease: Ubuntu 11.10
Package: libnux-1.0-0 1.14.0-0ubuntu1
ProcVersionSignature: Ubuntu 3.0.0-12.19-generic 3.0.4
Uname: Linux 3.0.0-12-generic x86_64
ApportVersion: 1.23-0ubuntu2
Architecture: amd64
CrashCounter: 1
Date: Sun Oct 2 18:19:14 2011
ExecutablePath: /usr/bin/compiz
InstallationMedia: Ubuntu 11.10 "Oneiric Ocelot" - Beta amd64 (20110901)
ProcCmdline: compiz
SegvAnalysis:
 Segfault happened at: 0x7fd55b0ca190 <_ZNK3nux15GraphicsDisplay12GetGpuDeviceEv>: mov 0x358(%rdi),%rax
 PC (0x7fd55b0ca190) ok
 source "0x358(%rdi)" (0x00000358) not located in a known VMA region (needed readable region)!
 destination "%rax" ok
SegvReason: reading NULL VMA
Signal: 11
SourcePackage: nux
StacktraceTop:
 nux::GraphicsDisplay::GetGpuDevice() const () from /usr/lib/libnux-graphics-1.0.so.0
 nux::StaticCairoText::UpdateTexture() () from /usr/lib/compiz/libunityshell.so
 nux::StaticCairoText::OnFontChanged(_GObject*, _GParamSpec*, void*) () from /usr/lib/compiz/libunityshell.so
 g_closure_invoke () from /usr/lib/x86_64-linux-gnu/libgobject-2.0.so.0
 ?? () from /usr/lib/x86_64-linux-gnu/libgobject-2.0.so.0
Title: compiz crashed with SIGSEGV in nux::GraphicsDisplay::GetGpuDevice()
UpgradeStatus: Upgraded to oneiric on 2011-09-14 (18 days ago)
UserGroups: adm admin cdrom dialout lpadmin plugdev sambashare vboxusers

[Apport retracing service (apport)]

StacktraceTop:
 nux::GraphicsDisplay::GetGpuDevice (this=0x0) at ./GraphicsDisplayX11.cpp:676
 texture_from_cairo_graphics (cg=<optimized out>) at /build/buildd/unity-4.20.0/plugins/unityshell/src/CairoTexture.h:41
 nux::StaticCairoText::UpdateTexture (this=0x329aa60) at /build/buildd/unity-4.20.0/plugins/unityshell/src/StaticCairoText.cpp:490
 nux::StaticCairoText::OnFontChanged (gobject=<optimized out>, pspec=<optimized out>, data=<optimized out>) at /build/buildd/unity-4.20.0/plugins/unityshell/src/StaticCairoText.cpp:505
 g_closure_invoke (closure=0x3867420, return_value=0x0, n_param_values=2, param_values=0x3fccad0, invocation_hint=<optimized out>) at /build/buildd/glib2.0-2.30.0/./gobject/gclosure.c:774

[Helge Jung (youngage)]

One addition: I was able to move the mouse the whole time - just that no mouse clicks and/or keyboard events etc. were recognized/handled.

[Jay Taoko (jaytaoko)]

According to the stack trace, we have nux::GetGraphicsDisplay() returning NULL in texture_from_cairo_graphics. This would happen if we are calling it from any thread other than the main thread.

[Andrea Azzarone (azzar1)]

Likely it has already been fixed. Please open a new bug if you are still affected.