Application: kwin (4.11.2)
KDE Platform Version: 4.11.2
Qt Version: 4.8.5
Operating System: Linux 3.11.6-200.fc19.x86_64 x86_64
Distribution (Platform): Fedora RPMs

-- Information about the crash:
- What I was doing when the application crashed:
This is a fairly new system, fedora 19, from less than a week ago. System had been fully updated a day ago. Only applications running were under non-root login, consisting of two konsoles (each on a separate monitor of a two-monitor setup). Both konsoles were "su -" root, but owned by the non-root login (likely unrelated to the crash, but being su root on the konsoles might change things)

 Failure occured when alt-tabbing between the two konsoles, and neither konsole was running any application.

I believe that the traces will not be enough to track this by itself, but it seems likely there is a thread issue which will randomly and quite rarely cause crashes in the future for other users, and will require a number of reports before any useful information is produced. The issue is non-fatal for other apps.

The crash does not seem to be reproducible.

-- Backtrace:
Application: KWin (kwin), signal: Segmentation fault
Using host libthread_db library "/lib64/libthread_db.so.1".
40	  int result = INLINE_SYSCALL (wait4, 4, pid, stat_loc, options, NULL);
[Current thread is 1 (Thread 0x7fd6097b7900 (LWP 1408))]

Thread 2 (Thread 0x7fd5f5a2a700 (LWP 1421)):
#0  pthread_cond_wait@@GLIBC_2.3.2 () at ../nptl/sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S:185
#1  0x00000031b93860bb in QTWTF::TCMalloc_PageHeap::scavengerThread (this=0x31b9683f00 <QTWTF::pageheap_memory>) at ../3rdparty/javascriptcore/JavaScriptCore/wtf/FastMalloc.cpp:2359
#2  0x00000031b93860f9 in QTWTF::TCMalloc_PageHeap::runScavengerThread (context=<optimized out>) at ../3rdparty/javascriptcore/JavaScriptCore/wtf/FastMalloc.cpp:1464
#3  0x0000003197c07c53 in start_thread (arg=0x7fd5f5a2a700) at pthread_create.c:308
#4  0x00000031974f5e1d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:113

Thread 1 (Thread 0x7fd6097b7900 (LWP 1408)):
[KCrash Handler]
#5  0x00000034a2ceac24 in KWin::effectWindow (w=0x7fd5f00012b0) at /usr/src/debug/kde-workspace-4.11.2/kwin/effects.cpp:1778
#6  0x00000034a2cc9114 in KWin::Scene::paintScreen (this=this@entry=0x1e37530, mask=mask@entry=0x7fffa04ef89c, region=region@entry=0x7fffa04ef950) at /usr/src/debug/kde-workspace-4.11.2/kwin/scene.cpp:143
#7  0x00000034a2cdb877 in KWin::SceneOpenGL::paint (this=0x1e37530, damage=..., toplevels=...) at /usr/src/debug/kde-workspace-4.11.2/kwin/scene_opengl.cpp:360
#8  0x00000034a2cc1093 in KWin::Compositor::performCompositing (this=0x2061da0) at /usr/src/debug/kde-workspace-4.11.2/kwin/composite.cpp:618
#9  0x00000031a2992141 in QObject::event (this=0x2061da0, e=<optimized out>) at kernel/qobject.cpp:1156
#10 0x00000031a5dc84dc in QApplicationPrivate::notify_helper (this=this@entry=0x1e8a1d0, receiver=receiver@entry=0x2061da0, e=e@entry=0x7fffa04efd40) at kernel/qapplication.cpp:4562
#11 0x00000031a5dceaa0 in QApplication::notify (this=this@entry=0x7fffa04f0210, receiver=receiver@entry=0x2061da0, e=e@entry=0x7fffa04efd40) at kernel/qapplication.cpp:4348
#12 0x000000349d63fe9a in KApplication::notify (this=0x7fffa04f0210, receiver=0x2061da0, event=0x7fffa04efd40) at /usr/src/debug/kdelibs-4.11.2/kdeui/kernel/kapplication.cpp:311
#13 0x00000031a297a26d in QCoreApplication::notifyInternal (this=0x7fffa04f0210, receiver=0x2061da0, event=0x7fffa04efd40) at kernel/qcoreapplication.cpp:949
#14 0x00000031a29a9c13 in sendEvent (event=<optimized out>, receiver=<optimized out>) at kernel/qcoreapplication.h:231
#15 QTimerInfoList::activateTimers (this=0x1e8abc8) at kernel/qeventdispatcher_unix.cpp:621
#16 0x00000031a29a9c90 in QEventDispatcherUNIX::activateTimers (this=this@entry=0x1de5c80) at kernel/qeventdispatcher_unix.cpp:878
#17 0x00000031a29aa600 in QEventDispatcherUNIX::processEvents (this=this@entry=0x1de5c80, flags=...) at kernel/qeventdispatcher_unix.cpp:940
#18 0x00000031a5e658e6 in QEventDispatcherX11::processEvents (this=0x1de5c80, flags=...) at kernel/qeventdispatcher_x11.cpp:152
#19 0x00000031a2978ecf in QEventLoop::processEvents (this=this@entry=0x7fffa04f0080, flags=...) at kernel/qeventloop.cpp:149
#20 0x00000031a29791c5 in QEventLoop::exec (this=this@entry=0x7fffa04f0080, flags=...) at kernel/qeventloop.cpp:204
#21 0x00000031a297e45b in QCoreApplication::exec () at kernel/qcoreapplication.cpp:1221
#22 0x00000031a5dc6c9c in QApplication::exec () at kernel/qapplication.cpp:3823
#23 0x00000034a2c7b806 in kdemain (argc=3, argv=0x7fffa04f0358) at /usr/src/debug/kde-workspace-4.11.2/kwin/main.cpp:597
#24 0x0000003197421b75 in __libc_start_main (main=0x4009d0 <main(int, char**)>, argc=3, ubp_av=0x7fffa04f0358, init=<optimized out>, fini=<optimized out>, rtld_fini=<optimized out>, stack_end=0x7fffa04f0348) at libc-start.c:274
#25 0x0000000000400a01 in _start ()

Possible duplicates by query: bug 326574, bug 325569, bug 323133, bug 321774, bug 321125.

Reported using DrKonqi