unity-panel-service crashed with SIGSEGV in g_type_check_instance_cast() - with a11y enabled

[Jean-Baptiste Lallement]

TEST CASE:
1. enable accessibility
2. reboot
3. login

Result:
The whole desktop freeze after using it for few minutes and this crash occurs together with atspi2 and dbus.
On a dual core, orca uses 1 CPU and DBus uses the other.

Related at-spi2 report: bug 829370

ProblemType: Crash
DistroRelease: Ubuntu 11.10
Package: unity-services 4.8.0-0ubuntu3
ProcVersionSignature: Ubuntu 3.0.0-8.11-generic 3.0.1
Uname: Linux 3.0.0-8-generic i686
Architecture: i386
CompizPlugins: [core,bailer,detection,composite,opengl,decor,move,mousepoll,resize,gnomecompat,snap,regex,grid,animation,compiztoolbox,imgpng,vpswitch,wall,place,expo,unitymtgrabhandles,session,workarounds,ezoom,staticswitcher,fade,scale,unityshell]
CrashCounter: 1
Date: Fri Aug 19 14:10:18 2011
ExecutablePath: /usr/lib/unity/unity-panel-service
InstallationMedia: Ubuntu 11.04 "Natty Narwhal" - Release i386 (20110427.1)
ProcCmdline: /usr/lib/unity/unity-panel-service
ProcEnviron:
 SHELL=/bin/bash
 PATH=(custom, no user)
 LANG=fr_FR.UTF-8
SegvAnalysis:
 Segfault happened at: 0x9505d8 <g_type_check_instance_cast+56>: mov (%eax),%ebp
 PC (0x009505d8) ok
 source "(%eax)" (0x00000008) not located in a known VMA region (needed readable region)!
 destination "%ebp" ok
SegvReason: reading NULL VMA
Signal: 11
SourcePackage: unity
StacktraceTop:
 g_type_check_instance_cast (type_instance=0xb6b20620, iface_type=135088432) at /build/buildd/glib2.0-2.29.16/./gobject/gtype.c:3985
 ?? () from /usr/lib/libgtk-3.so.0
 g_cclosure_marshal_VOID__PARAM (closure=0x8213150, return_value=0x0, n_param_values=2, param_values=0x821af90, invocation_hint=0xbf92e7b0, marshal_data=0x0) at /build/buildd/glib2.0-2.29.16/./gobject/gmarshal.c:539
 g_closure_invoke (closure=0x8213150, return_value=0x0, n_param_values=2, param_values=0x821af90, invocation_hint=0xbf92e7b0) at /build/buildd/glib2.0-2.29.16/./gobject/gclosure.c:773
 signal_emit_unlocked_R (node=0x80c23d8, detail=96, instance=0x81832a8, emission_return=0x0, instance_and_params=0x821af90) at /build/buildd/glib2.0-2.29.16/./gobject/gsignal.c:3271
Title: unity-panel-service crashed with SIGSEGV in g_type_check_instance_cast()
UpgradeStatus: Upgraded to oneiric on 2011-08-17 (2 days ago)
UserGroups: adm admin cdrom dialout lpadmin plugdev sambashare

[C de-Avillez (hggdh2)]

easily repeateble; new install of Oneiric.

[Guy Schlosser (guyster104)]

I am experiencing the same problem with the Unity Panel service and atspi2. When I login, I experience a load of crashes, among are atspi2 and Unity Panel service. The problem is even more enhanced by not being able to read anything on the desktop. I can get to the launcher panel, but when I launch something such as firefox, nothing but the window title and menu bar are read.

[Apport retracing service (apport)]

StacktraceTop:
 g_type_check_instance_cast (type_instance=0xb6b20620, iface_type=135088432) at /build/buildd/glib2.0-2.29.16/./gobject/gtype.c:3985
 notify_cb (obj=0x81832a8, pspec=0x80cc600) at /build/buildd/gtk+3.0-3.1.12/./gtk/a11y/gtkwidgetaccessible.c:62
 g_cclosure_marshal_VOID__PARAM (closure=0x8213150, return_value=0x0, n_param_values=2, param_values=0x821af90, invocation_hint=0xbf92e7b0, marshal_data=0x0) at /build/buildd/glib2.0-2.29.16/./gobject/gmarshal.c:539
 g_closure_invoke (closure=0x8213150, return_value=0x0, n_param_values=2, param_values=0x821af90, invocation_hint=0xbf92e7b0) at /build/buildd/glib2.0-2.29.16/./gobject/gclosure.c:773
 signal_emit_unlocked_R (node=0x80c23d8, detail=96, instance=0x81832a8, emission_return=0x0, instance_and_params=0x821af90) at /build/buildd/glib2.0-2.29.16/./gobject/gsignal.c:3271

[David Barth (dbarth)]

unity-2d is still the recommended environment for a11y

[Didier Roche-Tolomelli (didrocks)]

@David Barth, this is still critical, unity-panel-service is used in the unity-2d session…

[David Barth (dbarth)]

@jibel: is that still crashing? the atspi2 bug was fixed since this issue was reported

[Jean-Baptiste Lallement (jibel)]

I'm closing this report because it is no more an issue with latest Oneiric (20111003)