Application: kwin (4.6.4 (4.6.4))
KDE Platform Version: 4.6.4 (4.6.4)
Qt Version: 4.7.2
Operating System: Linux 2.6.38-8-generic i686
Distribution: Ubuntu 11.04

-- Information about the crash:
- Unusual behavior I noticed:
I had activated the screensaver with the option for the screen to go blank after about 5 mins of inactivity.  After this feature had been unabled, I noticed that whenever I press on the mousepad and/or keyboard for the screen to reappear, the sreen-prompt for password displays incomplete. Immediately  after that, a dialogue window appears informing me that KWin has crashed.

The crash can be reproduced some of the time.

-- Backtrace:
Application: KWin (kwin), signal: Segmentation fault
[Current thread is 1 (Thread 0xb784c720 (LWP 2490))]

Thread 3 (Thread 0xb29eeb70 (LWP 2494)):
#0  0x00e22d41 in clock_gettime () from /lib/i386-linux-gnu/librt.so.1
#1  0x05ba0dd8 in do_gettime () at tools/qelapsedtimer_unix.cpp:123
#2  qt_gettime () at tools/qelapsedtimer_unix.cpp:140
#3  0x05c6d4f2 in updateCurrentTime (this=0x956c230, tm=...) at kernel/qeventdispatcher_unix.cpp:339
#4  QTimerInfoList::timerWait (this=0x956c230, tm=...) at kernel/qeventdispatcher_unix.cpp:442
#5  0x05c6f3a3 in QEventDispatcherUNIX::processEvents (this=0x9653450, flags=...) at kernel/qeventdispatcher_unix.cpp:906
#6  0x05c3e289 in QEventLoop::processEvents (this=0xb29ee280, flags=...) at kernel/qeventloop.cpp:149
#7  0x05c3e522 in QEventLoop::exec (this=0xb29ee280, flags=...) at kernel/qeventloop.cpp:201
#8  0x05b482a0 in QThread::exec (this=0x9591630) at thread/qthread.cpp:492
#9  0x05c1ffdb in QInotifyFileSystemWatcherEngine::run (this=0x9591630) at io/qfilesystemwatcher_inotify.cpp:248
#10 0x05b4ada2 in QThreadPrivate::start (arg=0x9591630) at thread/qthread_unix.cpp:320
#11 0x00dd8e99 in start_thread () from /lib/i386-linux-gnu/libpthread.so.0
#12 0x0048373e in clone () from /lib/i386-linux-gnu/libc.so.6

Thread 2 (Thread 0xb21edb70 (LWP 2497)):
#0  0x00e0d416 in __kernel_vsyscall ()
#1  0x00ddd48c in pthread_cond_wait@@GLIBC_2.3.2 () from /lib/i386-linux-gnu/libpthread.so.0
#2  0x004913fd in pthread_cond_wait () from /lib/i386-linux-gnu/libc.so.6
#3  0x010cb817 in QTWTF::TCMalloc_PageHeap::scavengerThread (this=0x11df1c0) at ../3rdparty/javascriptcore/JavaScriptCore/wtf/FastMalloc.cpp:2359
#4  0x010cb851 in QTWTF::TCMalloc_PageHeap::runScavengerThread (context=0x11df1c0) at ../3rdparty/javascriptcore/JavaScriptCore/wtf/FastMalloc.cpp:1464
#5  0x00dd8e99 in start_thread () from /lib/i386-linux-gnu/libpthread.so.0
#6  0x0048373e in clone () from /lib/i386-linux-gnu/libc.so.6

Thread 1 (Thread 0xb784c720 (LWP 2490)):
[KCrash Handler]
#7  intel_region_buffer (intel=0x903fbf8, region=0x0, flag=2) at intel_regions.c:514
#8  0x03bbbce2 in intelClearWithBlit (ctx=0x903fbf8, mask=2) at intel_blit.c:262
#9  0x03bbe4c0 in intelClear (ctx=0x903fbf8, mask=2) at intel_clear.c:177
#10 0x03c84512 in _mesa_Clear (mask=<value optimized out>) at main/clear.c:241
#11 0x00ef977b in KWin::SceneOpenGL::paintBackground (this=0x903b618, region=...) at ../../kwin/scene_opengl.cpp:921
#12 0x00ef0492 in KWin::Scene::paintGenericScreen (this=0x903b618, orig_mask=32) at ../../kwin/scene.cpp:188
#13 0x00ef9961 in KWin::SceneOpenGL::paintGenericScreen (this=0x903b618, mask=32, data=...) at ../../kwin/scene_opengl.cpp:909
#14 0x00eed6f0 in KWin::Scene::finalPaintScreen (this=0x903b618, mask=32, region=..., data=...) at ../../kwin/scene.cpp:178
#15 0x00f0f02c in KWin::EffectsHandlerImpl::paintScreen (this=0x936eb70, mask=32, region=..., data=...) at ../../kwin/effects.cpp:173
#16 0x04096159 in KWin::StartupFeedbackEffect::paintScreen (this=0x94f92f8, mask=32, region=..., data=...) at ../../../kwin/effects/startupfeedback/startupfeedback.cpp:166
#17 0x00f0f0a2 in KWin::EffectsHandlerImpl::paintScreen (this=0x936eb70, mask=32, region=..., data=...) at ../../kwin/effects.cpp:169
#18 0x00647256 in KWin::Effect::paintScreen (this=0x939cbd8, mask=32, region=..., data=...) at ../../../kwin/lib/kwineffects.cpp:227
#19 0x00f0f0a2 in KWin::EffectsHandlerImpl::paintScreen (this=0x936eb70, mask=32, region=..., data=...) at ../../kwin/effects.cpp:169
#20 0x040380af in KWin::LogoutEffect::paintScreen (this=0x948b298, mask=32, region=..., data=...) at ../../../kwin/effects/logout/logout.cpp:207
#21 0x00f0f0a2 in KWin::EffectsHandlerImpl::paintScreen (this=0x936eb70, mask=32, region=..., data=...) at ../../kwin/effects.cpp:169
#22 0x04053b40 in KWin::ShadowEffect::paintScreen (this=0x955ba48, mask=32, region=..., data=...) at ../../../kwin/effects/shadow/shadow.cpp:189
#23 0x00f0f0a2 in KWin::EffectsHandlerImpl::paintScreen (this=0x936eb70, mask=32, region=..., data=...) at ../../kwin/effects.cpp:169
#24 0x04068043 in KWin::BlurEffect::paintScreen (this=0x93bb138, mask=32, region=..., data=...) at ../../../kwin/effects/blur/blur.cpp:230
#25 0x00f0f0a2 in KWin::EffectsHandlerImpl::paintScreen (this=0x936eb70, mask=0, region=..., data=...) at ../../kwin/effects.cpp:169
#26 0x0403ce9f in KWin::PresentWindowsEffect::paintScreen (this=0x93beab8, mask=0, region=..., data=...) at ../../../kwin/effects/presentwindows/presentwindows.cpp:205
#27 0x00f0f0a2 in KWin::EffectsHandlerImpl::paintScreen (this=0x936eb70, mask=0, region=..., data=...) at ../../kwin/effects.cpp:169
#28 0x00647256 in KWin::Effect::paintScreen (this=0x94f9290, mask=0, region=..., data=...) at ../../../kwin/lib/kwineffects.cpp:227
#29 0x00f0f0a2 in KWin::EffectsHandlerImpl::paintScreen (this=0x936eb70, mask=0, region=..., data=...) at ../../kwin/effects.cpp:169
#30 0x00647256 in KWin::Effect::paintScreen (this=0x9547a60, mask=0, region=..., data=...) at ../../../kwin/lib/kwineffects.cpp:227
#31 0x00f0f0a2 in KWin::EffectsHandlerImpl::paintScreen (this=0x936eb70, mask=0, region=..., data=...) at ../../kwin/effects.cpp:169
#32 0x00647256 in KWin::Effect::paintScreen (this=0x940fd50, mask=0, region=..., data=...) at ../../../kwin/lib/kwineffects.cpp:227
#33 0x00f0f0a2 in KWin::EffectsHandlerImpl::paintScreen (this=0x936eb70, mask=0, region=..., data=...) at ../../kwin/effects.cpp:169
#34 0x00647256 in KWin::Effect::paintScreen (this=0x9408220, mask=0, region=..., data=...) at ../../../kwin/lib/kwineffects.cpp:227
#35 0x00f0f0a2 in KWin::EffectsHandlerImpl::paintScreen (this=0x936eb70, mask=0, region=..., data=...) at ../../kwin/effects.cpp:169
#36 0x04023809 in KWin::DesktopGridEffect::paintScreen (this=0x93b9538, mask=0, region=..., data=...) at ../../../kwin/effects/desktopgrid/desktopgrid.cpp:156
#37 0x00f0f0a2 in KWin::EffectsHandlerImpl::paintScreen (this=0x936eb70, mask=0, region=..., data=...) at ../../kwin/effects.cpp:169
#38 0x0405ad12 in KWin::SlideEffect::paintScreen (this=0x9418a98, mask=0, region=..., data=...) at ../../../kwin/effects/slide/slide.cpp:86
#39 0x00f0f0a2 in KWin::EffectsHandlerImpl::paintScreen (this=0x936eb70, mask=0, region=..., data=...) at ../../kwin/effects.cpp:169
#40 0x0401c799 in KWin::BoxSwitchEffect::paintScreen (this=0x9499c78, mask=0, region=..., data=...) at ../../../kwin/effects/boxswitch/boxswitch.cpp:143
#41 0x00f0f0a2 in KWin::EffectsHandlerImpl::paintScreen (this=0x936eb70, mask=0, region=..., data=...) at ../../kwin/effects.cpp:169
#42 0x04076c1c in KWin::CubeEffect::paintScreen (this=0x94d1e78, mask=0, region=..., data=...) at ../../../kwin/effects/cube/cube.cpp:698
#43 0x00f0f0a2 in KWin::EffectsHandlerImpl::paintScreen (this=0x936eb70, mask=0, region=..., data=...) at ../../kwin/effects.cpp:169
#44 0x00647256 in KWin::Effect::paintScreen (this=0x94d2910, mask=0, region=..., data=...) at ../../../kwin/lib/kwineffects.cpp:227
#45 0x00f0f0a2 in KWin::EffectsHandlerImpl::paintScreen (this=0x936eb70, mask=0, region=..., data=...) at ../../kwin/effects.cpp:169
#46 0x00647256 in KWin::Effect::paintScreen (this=0x95480b8, mask=0, region=..., data=...) at ../../../kwin/lib/kwineffects.cpp:227
#47 0x00f0f0a2 in KWin::EffectsHandlerImpl::paintScreen (this=0x936eb70, mask=0, region=..., data=...) at ../../kwin/effects.cpp:169
#48 0x00647256 in KWin::Effect::paintScreen (this=0x93be9d0, mask=0, region=..., data=...) at ../../../kwin/lib/kwineffects.cpp:227
#49 0x00f0f0a2 in KWin::EffectsHandlerImpl::paintScreen (this=0x936eb70, mask=0, region=..., data=...) at ../../kwin/effects.cpp:169
#50 0x0406fa5c in KWin::CoverSwitchEffect::paintScreen (this=0x9547cb8, mask=0, region=..., data=...) at ../../../kwin/effects/coverswitch/coverswitch.cpp:126
#51 0x00f0f0a2 in KWin::EffectsHandlerImpl::paintScreen (this=0x936eb70, mask=0, region=..., data=...) at ../../kwin/effects.cpp:169
#52 0x00647256 in KWin::Effect::paintScreen (this=0x93ba628, mask=0, region=..., data=...) at ../../../kwin/lib/kwineffects.cpp:227
#53 0x00f0f0a2 in KWin::EffectsHandlerImpl::paintScreen (this=0x936eb70, mask=0, region=..., data=...) at ../../kwin/effects.cpp:169
#54 0x00647256 in KWin::Effect::paintScreen (this=0x9437e88, mask=0, region=..., data=...) at ../../../kwin/lib/kwineffects.cpp:227
#55 0x00f0f0a2 in KWin::EffectsHandlerImpl::paintScreen (this=0x936eb70, mask=0, region=..., data=...) at ../../kwin/effects.cpp:169
#56 0x040650f1 in KWin::ZoomEffect::paintScreen (this=0x95461d0, mask=0, region=..., data=...) at ../../../kwin/effects/zoom/zoom.cpp:341
#57 0x00f0f0a2 in KWin::EffectsHandlerImpl::paintScreen (this=0x936eb70, mask=0, region=..., data=...) at ../../kwin/effects.cpp:169
#58 0x00eee8bc in KWin::Scene::paintScreen (this=0x903b618, mask=0xbfce3388, region=0xbfce3410) at ../../kwin/scene.cpp:137
#59 0x00f05892 in KWin::SceneOpenGL::paint (this=0x903b618, damage=..., toplevels=...) at ../../kwin/scene_opengl.cpp:772
#60 0x00eea7b6 in KWin::Workspace::performCompositing (this=0xb404c1e8) at ../../kwin/composite.cpp:448
#61 0x05c54214 in QObject::event (this=0xb404c1e8, e=0xbfce393c) at kernel/qobject.cpp:1190
#62 0x06251d24 in QApplicationPrivate::notify_helper (this=0x8f864e8, receiver=0xb404c1e8, e=0xbfce393c) at kernel/qapplication.cpp:4462
#63 0x062568ce in QApplication::notify (this=0xbfce3c54, receiver=0xb404c1e8, e=0xbfce393c) at kernel/qapplication.cpp:3862
#64 0x008b436a in KApplication::notify (this=0xbfce3c54, receiver=0xb404c1e8, event=0xbfce393c) at ../../kdeui/kernel/kapplication.cpp:311
#65 0x00e799ef in KWin::Application::notify (this=0xbfce3c54, o=0xb404c1e8, e=0xbfce393c) at ../../kwin/main.cpp:376
#66 0x05c3f0bb in QCoreApplication::notifyInternal (this=0xbfce3c54, receiver=0xb404c1e8, event=0xbfce393c) at kernel/qcoreapplication.cpp:731
#67 0x05c6f1e4 in sendEvent (this=0x8f88218) at ../../include/QtCore/../../src/corelib/kernel/qcoreapplication.h:215
#68 QTimerInfoList::activateTimers (this=0x8f88218) at kernel/qeventdispatcher_unix.cpp:604
#69 0x05c6f338 in QEventDispatcherUNIX::processEvents (this=0x8f45aa8, flags=...) at kernel/qeventdispatcher_unix.cpp:923
#70 0x063067ea in QEventDispatcherX11::processEvents (this=0x8f45aa8, flags=...) at kernel/qeventdispatcher_x11.cpp:152
#71 0x05c3e289 in QEventLoop::processEvents (this=0xbfce3b94, flags=...) at kernel/qeventloop.cpp:149
#72 0x05c3e522 in QEventLoop::exec (this=0xbfce3b94, flags=...) at kernel/qeventloop.cpp:201
#73 0x05c42ecc in QCoreApplication::exec () at kernel/qcoreapplication.cpp:1008
#74 0x0624f8e7 in QApplication::exec () at kernel/qapplication.cpp:3736
#75 0x00e7c4e2 in kdemain (argc=3, argv=0xbfce3ed4) at ../../kwin/main.cpp:542
#76 0x080485bb in main (argc=3, argv=0xbfce3ed4) at kwin_dummy.cpp:3

This bug may be a duplicate of or related to bug 252817.

Possible duplicates by query: bug 276860, bug 276797, bug 276695, bug 276588, bug 276484.

Reported using DrKonqi