** Description changed:

+ [Impact]
+ Users running the nouveau X driver with the egl_dri2 mesa driver may 
experience a windowing system crash (kwin_gles, etc.) in the 
nv50_screen_fence_update() routine.
+ 
+ [Development Fix]
+ The problem was fixed upstream in mesa 8.0 which we are shipping in Precise.  
The patch switches from using a context object for flushing purposes, to a 
screen object; the context object can go NULL sometimes which leads to the 
crash.
+ 
+ [Stable Fix]
+ Upstream also created a backport of the mesa 8.0 patch to 7.11, although at 
time of writing this was not yet released in a 7.11.x point release.  The patch 
applies cleanly to the oneiric mesa and is what we're using for this SRU.
+ 
+ [Text Case]
+ 1. install nouveau video driver
+ 2. call /usr/bin/es2_info from mesa-utils-extra
+ Broken Behavior: application crashes
+ Fixed Behavior: egl information is printed out
+ 
+ [Regression Potential]
+ The scope of this patch is limited to nouveau (and specifically to newer 
NVIDIA cards).  Indeed it probably has no effect on non-egl window systems 
(like Unity/Compiz), so the scope is probably quite small.
+ 
+ Since the patch is included upstream as part of the mesa 8.0 tree, and
+ is selected for the 7.11 stable series, the patch is likely quite safe.
+ If there were any regressions caused by this, I would expect symptoms
+ similar to the original bug (i.e. crashes).
+ 
+ [Original Report]
  called /usr/bin/es2_info from mesa-utils-extra
  
  ProblemType: Crash
  DistroRelease: Ubuntu 11.10
  Package: mesa-utils-extra 8.0.1+git20110129+d8f7d6b-0ubuntu2
  ProcVersionSignature: Ubuntu 3.0.0-15.26-generic 3.0.13
  Uname: Linux 3.0.0-15-generic x86_64
  ApportVersion: 1.23-0ubuntu4
  Architecture: amd64
  Date: Sat Feb  4 23:52:38 2012
  ExecutablePath: /usr/bin/es2_info
  InstallationMedia: Ubuntu 11.10 "Oneiric Ocelot" - Release amd64 (20111012)
  ProcCmdline: es2_info
  SegvAnalysis:
-  Segfault happened at: 0x7fcea9943fa7:        mov    (%rax),%eax
-  PC (0x7fcea9943fa7) ok
-  source "(%rax)" (0x7fceacc81000) not located in a known VMA region (needed 
readable region)!
-  destination "%eax" ok
+  Segfault happened at: 0x7fcea9943fa7:        mov    (%rax),%eax
+  PC (0x7fcea9943fa7) ok
+  source "(%rax)" (0x7fceacc81000) not located in a known VMA region (needed 
readable region)!
+  destination "%eax" ok
  SegvReason: reading unknown VMA
  Signal: 11
  SourcePackage: mesa-demos
  StacktraceTop:
-  ?? () from /usr/lib/x86_64-linux-gnu/egl/egl_gallium.so
-  nouveau_fence_update () from /usr/lib/x86_64-linux-gnu/egl/egl_gallium.so
-  nv50_default_flush_notify () from 
/usr/lib/x86_64-linux-gnu/egl/egl_gallium.so
-  nouveau_pushbuf_flush () from /usr/lib/x86_64-linux-gnu/libdrm_nouveau.so.1
-  nouveau_grobj_free () from /usr/lib/x86_64-linux-gnu/libdrm_nouveau.so.1
+  ?? () from /usr/lib/x86_64-linux-gnu/egl/egl_gallium.so
+  nouveau_fence_update () from /usr/lib/x86_64-linux-gnu/egl/egl_gallium.so
+  nv50_default_flush_notify () from 
/usr/lib/x86_64-linux-gnu/egl/egl_gallium.so
+  nouveau_pushbuf_flush () from /usr/lib/x86_64-linux-gnu/libdrm_nouveau.so.1
+  nouveau_grobj_free () from /usr/lib/x86_64-linux-gnu/libdrm_nouveau.so.1
  Title: es2_info crashed with SIGSEGV in nouveau_fence_update()
  UpgradeStatus: No upgrade log present (probably fresh install)
  UserGroups: adm admin cdrom dialout lpadmin plugdev sambashare users

-- 
You received this bug notification because you are a member of Ubuntu
Bugs, which is subscribed to Ubuntu.
https://bugs.launchpad.net/bugs/926918

Title:
  es2_info crashed with SIGSEGV in nv50_screen_fence_update()

To manage notifications about this bug go to:
https://bugs.launchpad.net/mesa/+bug/926918/+subscriptions

-- 
ubuntu-bugs mailing list
[email protected]
https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs

Reply via email to