Application: plasmashell (5.5.5)

Qt Version: 5.5.1
Operating System: Linux 4.5.0-ck1 x86_64
Distribution: Ubuntu 16.04 LTS

-- Information about the crash:
- What I was doing when the application crashed:

As per bug 362742 https://bugs.kde.org/show_bug.cgi?id=362742 I reproduced exactly the same crash but unfortunately the crash assistant failed to recognise that the crash was the same and the bug in the crash reporting assistant preventing me from attaching a new crash to an existing bug means I have to submit a duplicate report. Nonetheless this is happening quite often now, if the session has been locked for many hours (usually a day).

The crash can be reproduced sometimes.

-- Backtrace:
Application: Plasma (plasmashell), signal: Segmentation fault
Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".
pthread_cond_wait@@GLIBC_2.3.2 () at ../sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S:185
[Current thread is 1 (Thread 0x7f809db98900 (LWP 13223))]

Thread 8 (Thread 0x7f8088528700 (LWP 13239)):
#0  0x00007f80982a7e8d in poll () at ../sysdeps/unix/syscall-template.S:84
#1  0x00007f809c36cc62 in _xcb_conn_wait (__timeout=-1, __nfds=1, __fds=0x7f8088527bc0) at /usr/include/x86_64-linux-gnu/bits/poll2.h:46
#2  0x00007f809c36cc62 in _xcb_conn_wait (c=c@entry=0x1486730, cond=cond@entry=0x1486770, vector=vector@entry=0x0, count=count@entry=0x0) at ../../src/xcb_conn.c:459
#3  0x00007f809c36e8d7 in xcb_wait_for_event (c=0x1486730) at ../../src/xcb_in.c:693
#4  0x00007f808aca8629 in QXcbEventReader::run() (this=0x1494890) at qxcbconnection.cpp:1253
#5  0x00007f809899d84e in QThreadPrivate::start(void*) (arg=0x1494890) at thread/qthread_unix.cpp:331
#6  0x00007f8097a8a6fa in start_thread (arg=0x7f8088528700) at pthread_create.c:333
#7  0x00007f80982b3b5d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

Thread 7 (Thread 0x7f80854ca700 (LWP 13241)):
#0  0x00007f80982a39cd in read () at ../sysdeps/unix/syscall-template.S:84
#1  0x00007f8090e54073 in  () at /usr/lib/x86_64-linux-gnu/tls/libnvidia-tls.so.361.28
#2  0x00007f80950806c0 in g_wakeup_acknowledge (__nbytes=16, __buf=0x7f80854c9aa0, __fd=<optimized out>) at /usr/include/x86_64-linux-gnu/bits/unistd.h:44
#3  0x00007f80950806c0 in g_wakeup_acknowledge (wakeup=0x7f80800015b0) at /build/glib2.0-t9oPgV/glib2.0-2.48.0/./glib/gwakeup.c:210
#4  0x00007f809503ce04 in g_main_context_check (context=context@entry=0x7f8078000990, max_priority=2147483647, fds=fds@entry=0x7f8078003070, n_fds=n_fds@entry=1) at /build/glib2.0-t9oPgV/glib2.0-2.48.0/./glib/gmain.c:3632
#5  0x00007f809503d2c0 in g_main_context_iterate (context=context@entry=0x7f8078000990, block=block@entry=1, dispatch=dispatch@entry=1, self=<optimized out>) at /build/glib2.0-t9oPgV/glib2.0-2.48.0/./glib/gmain.c:3837
#6  0x00007f809503d42c in g_main_context_iteration (context=0x7f8078000990, may_block=may_block@entry=1) at /build/glib2.0-t9oPgV/glib2.0-2.48.0/./glib/gmain.c:3901
#7  0x00007f8098bd4a9b in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) (this=0x7f80780008c0, flags=...) at kernel/qeventdispatcher_glib.cpp:420
#8  0x00007f8098b7bdea in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) (this=this@entry=0x7f80854c9ca0, flags=..., flags@entry=...) at kernel/qeventloop.cpp:204
#9  0x00007f80989988a4 in QThread::exec() (this=<optimized out>) at thread/qthread.cpp:503
#10 0x00007f809b2403c5 in  () at /usr/lib/x86_64-linux-gnu/libQt5Qml.so.5
#11 0x00007f809899d84e in QThreadPrivate::start(void*) (arg=0x158c470) at thread/qthread_unix.cpp:331
#12 0x00007f8097a8a6fa in start_thread (arg=0x7f80854ca700) at pthread_create.c:333
#13 0x00007f80982b3b5d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

Thread 6 (Thread 0x7f8076b7c700 (LWP 13242)):
#0  0x00007f8095081a49 in g_mutex_lock (mutex=mutex@entry=0x7f8070000990) at /build/glib2.0-t9oPgV/glib2.0-2.48.0/./glib/gthread-posix.c:1338
#1  0x00007f809503d302 in g_main_context_iterate (priority=2147483647, n_fds=1, fds=0x7f8070002e70, timeout=<optimized out>, context=0x7f8070000990) at /build/glib2.0-t9oPgV/glib2.0-2.48.0/./glib/gmain.c:4130
#2  0x00007f809503d302 in g_main_context_iterate (context=context@entry=0x7f8070000990, block=block@entry=1, dispatch=dispatch@entry=1, self=<optimized out>) at /build/glib2.0-t9oPgV/glib2.0-2.48.0/./glib/gmain.c:3835
#3  0x00007f809503d42c in g_main_context_iteration (context=0x7f8070000990, may_block=may_block@entry=1) at /build/glib2.0-t9oPgV/glib2.0-2.48.0/./glib/gmain.c:3901
#4  0x00007f8098bd4a9b in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) (this=0x7f80700008c0, flags=...) at kernel/qeventdispatcher_glib.cpp:420
#5  0x00007f8098b7bdea in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) (this=this@entry=0x7f8076b7bca0, flags=..., flags@entry=...) at kernel/qeventloop.cpp:204
#6  0x00007f80989988a4 in QThread::exec() (this=<optimized out>) at thread/qthread.cpp:503
#7  0x00007f809b2403c5 in  () at /usr/lib/x86_64-linux-gnu/libQt5Qml.so.5
#8  0x00007f809899d84e in QThreadPrivate::start(void*) (arg=0x16ca4f0) at thread/qthread_unix.cpp:331
#9  0x00007f8097a8a6fa in start_thread (arg=0x7f8076b7c700) at pthread_create.c:333
#10 0x00007f80982b3b5d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

Thread 5 (Thread 0x7f8074aed700 (LWP 13243)):
#0  0x00007f80982a7e8d in poll () at ../sysdeps/unix/syscall-template.S:84
#1  0x00007f809503d31c in g_main_context_iterate (priority=2147483647, n_fds=1, fds=0x7f8068003070, timeout=<optimized out>, context=0x7f8068000990) at /build/glib2.0-t9oPgV/glib2.0-2.48.0/./glib/gmain.c:4135
#2  0x00007f809503d31c in g_main_context_iterate (context=context@entry=0x7f8068000990, block=block@entry=1, dispatch=dispatch@entry=1, self=<optimized out>) at /build/glib2.0-t9oPgV/glib2.0-2.48.0/./glib/gmain.c:3835
#3  0x00007f809503d42c in g_main_context_iteration (context=0x7f8068000990, may_block=may_block@entry=1) at /build/glib2.0-t9oPgV/glib2.0-2.48.0/./glib/gmain.c:3901
#4  0x00007f8098bd4a9b in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) (this=0x7f80680008c0, flags=...) at kernel/qeventdispatcher_glib.cpp:420
#5  0x00007f8098b7bdea in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) (this=this@entry=0x7f8074aecca0, flags=..., flags@entry=...) at kernel/qeventloop.cpp:204
#6  0x00007f80989988a4 in QThread::exec() (this=<optimized out>) at thread/qthread.cpp:503
#7  0x00007f809b2403c5 in  () at /usr/lib/x86_64-linux-gnu/libQt5Qml.so.5
#8  0x00007f809899d84e in QThreadPrivate::start(void*) (arg=0x1a41720) at thread/qthread_unix.cpp:331
#9  0x00007f8097a8a6fa in start_thread (arg=0x7f8074aed700) at pthread_create.c:333
#10 0x00007f80982b3b5d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

Thread 4 (Thread 0x7f806f1d0700 (LWP 13244)):
#0  0x00007f8097a903a0 in pthread_cond_wait@@GLIBC_2.3.2 () at ../sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S:185
#1  0x00007f809d5e5bd4 in  () at /usr/lib/x86_64-linux-gnu/libQt5Script.so.5
#2  0x00007f809d5e5c19 in  () at /usr/lib/x86_64-linux-gnu/libQt5Script.so.5
#3  0x00007f8097a8a6fa in start_thread (arg=0x7f806f1d0700) at pthread_create.c:333
#4  0x00007f80982b3b5d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

Thread 3 (Thread 0x7f7fe7fff700 (LWP 13245)):
#0  0x00007f8095081a49 in g_mutex_lock (mutex=mutex@entry=0x7f7fe0000990) at /build/glib2.0-t9oPgV/glib2.0-2.48.0/./glib/gthread-posix.c:1338
#1  0x00007f809503c3f4 in g_main_context_release (context=0x7f7fe0000990) at /build/glib2.0-t9oPgV/glib2.0-2.48.0/./glib/gmain.c:3248
#2  0x00007f809503d2d6 in g_main_context_iterate (context=context@entry=0x7f7fe0000990, block=block@entry=1, dispatch=dispatch@entry=1, self=<optimized out>) at /build/glib2.0-t9oPgV/glib2.0-2.48.0/./glib/gmain.c:3842
#3  0x00007f809503d42c in g_main_context_iteration (context=0x7f7fe0000990, may_block=may_block@entry=1) at /build/glib2.0-t9oPgV/glib2.0-2.48.0/./glib/gmain.c:3901
#4  0x00007f8098bd4a9b in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) (this=0x7f7fe00008c0, flags=...) at kernel/qeventdispatcher_glib.cpp:420
#5  0x00007f8098b7bdea in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) (this=this@entry=0x7f7fe7ffec50, flags=..., flags@entry=...) at kernel/qeventloop.cpp:204
#6  0x00007f80989988a4 in QThread::exec() (this=<optimized out>) at thread/qthread.cpp:503
#7  0x00007f809bbc6ed6 in  () at /usr/lib/x86_64-linux-gnu/libQt5Quick.so.5
#8  0x00007f809899d84e in QThreadPrivate::start(void*) (arg=0x1d10630) at thread/qthread_unix.cpp:331
#9  0x00007f8097a8a6fa in start_thread (arg=0x7f7fe7fff700) at pthread_create.c:333
#10 0x00007f80982b3b5d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

Thread 2 (Thread 0x7f7fe77fe700 (LWP 13246)):
[KCrash Handler]
#6  0x00007f809825668d in __strstr_sse2_unaligned () at ../sysdeps/x86_64/multiarch/strstr-sse2-unaligned.S:40
#7  0x00007f809bc19aca in QSGRenderContext::initialize(QOpenGLContext*) () at /usr/lib/x86_64-linux-gnu/libQt5Quick.so.5
#8  0x00007f809bc3d409 in  () at /usr/lib/x86_64-linux-gnu/libQt5Quick.so.5
#9  0x00007f809899d84e in QThreadPrivate::start(void*) (arg=0x1bae4b0) at thread/qthread_unix.cpp:331
#10 0x00007f8097a8a6fa in start_thread (arg=0x7f7fe77fe700) at pthread_create.c:333
#11 0x00007f80982b3b5d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

Thread 1 (Thread 0x7f809db98900 (LWP 13223)):
#0  0x00007f8097a903a0 in pthread_cond_wait@@GLIBC_2.3.2 () at ../sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S:185
#1  0x00007f809899eaeb in QWaitCondition::wait(QMutex*, unsigned long) (time=18446744073709551615, this=0x1c75cd0) at thread/qwaitcondition_unix.cpp:136
#2  0x00007f809899eaeb in QWaitCondition::wait(QMutex*, unsigned long) (this=<optimized out>, mutex=0x1bae4f0, time=18446744073709551615) at thread/qwaitcondition_unix.cpp:208
#3  0x00007f809bc39bc6 in  () at /usr/lib/x86_64-linux-gnu/libQt5Quick.so.5
#4  0x00007f809bc3c09c in  () at /usr/lib/x86_64-linux-gnu/libQt5Quick.so.5
#5  0x00007f809bc3c733 in  () at /usr/lib/x86_64-linux-gnu/libQt5Quick.so.5
#6  0x00007f8098ec92e5 in QWindow::event(QEvent*) (this=0x1c58ae0, ev=<optimized out>) at kernel/qwindow.cpp:2060
#7  0x00007f809bc6f871 in QQuickWindow::event(QEvent*) () at /usr/lib/x86_64-linux-gnu/libQt5Quick.so.5
#8  0x000000000043f206 in DesktopView::event(QEvent*) (this=0x1c58ae0, e=0x7ffe5660b520) at /build/plasma-workspace-kxRFE_/plasma-workspace-5.5.5.2/shell/desktopview.cpp:205
#9  0x00007f809968105c in QApplicationPrivate::notify_helper(QObject*, QEvent*) (this=this@entry=0x1460460, receiver=receiver@entry=0x1c58ae0, e=e@entry=0x7ffe5660b520) at kernel/qapplication.cpp:3716
#10 0x00007f8099686516 in QApplication::notify(QObject*, QEvent*) (this=0x7ffe5660b940, receiver=0x1c58ae0, e=0x7ffe5660b520) at kernel/qapplication.cpp:3499
#11 0x00007f8098b7e62b in QCoreApplication::notifyInternal(QObject*, QEvent*) (this=0x7ffe5660b940, receiver=receiver@entry=0x1c58ae0, event=event@entry=0x7ffe5660b520) at kernel/qcoreapplication.cpp:965
#12 0x00007f8098ec14ec in QGuiApplicationPrivate::processExposeEvent(QWindowSystemInterfacePrivate::ExposeEvent*) (event=0x7ffe5660b520, receiver=0x1c58ae0) at ../../include/QtCore/../../src/corelib/kernel/qcoreapplication.h:227
#13 0x00007f8098ec14ec in QGuiApplicationPrivate::processExposeEvent(QWindowSystemInterfacePrivate::ExposeEvent*) (e=0x1c1d2d0) at kernel/qguiapplication.cpp:2663
#14 0x00007f8098ec225d in QGuiApplicationPrivate::processWindowSystemEvent(QWindowSystemInterfacePrivate::WindowSystemEvent*) (e=e@entry=0x1c1d2d0) at kernel/qguiapplication.cpp:1658
#15 0x00007f8098ea5f38 in QWindowSystemInterface::sendWindowSystemEvents(QFlags<QEventLoop::ProcessEventsFlag>) (flags=...) at kernel/qwindowsysteminterface.cpp:625
#16 0x00007f808acd9f10 in userEventSourceDispatch(GSource*, GSourceFunc, gpointer) (source=<optimized out>) at eventdispatchers/qeventdispatcher_glib.cpp:70
#17 0x00007f809503d127 in g_main_context_dispatch (context=0x7f8080001710) at /build/glib2.0-t9oPgV/glib2.0-2.48.0/./glib/gmain.c:3154
#18 0x00007f809503d127 in g_main_context_dispatch (context=context@entry=0x7f8080001710) at /build/glib2.0-t9oPgV/glib2.0-2.48.0/./glib/gmain.c:3769
#19 0x00007f809503d380 in g_main_context_iterate (context=context@entry=0x7f8080001710, block=block@entry=1, dispatch=dispatch@entry=1, self=<optimized out>) at /build/glib2.0-t9oPgV/glib2.0-2.48.0/./glib/gmain.c:3840
#20 0x00007f809503d42c in g_main_context_iteration (context=0x7f8080001710, may_block=may_block@entry=1) at /build/glib2.0-t9oPgV/glib2.0-2.48.0/./glib/gmain.c:3901
#21 0x00007f8098bd4a7f in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) (this=0x14b8170, flags=...) at kernel/qeventdispatcher_glib.cpp:418
#22 0x00007f8098b7bdea in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) (this=this@entry=0x7ffe5660b7e0, flags=..., flags@entry=...) at kernel/qeventloop.cpp:204
#23 0x00007f8098b83e8c in QCoreApplication::exec() () at kernel/qcoreapplication.cpp:1229
#24 0x00007f8098eb7c3c in QGuiApplication::exec() () at kernel/qguiapplication.cpp:1542
#25 0x00007f809967d495 in QApplication::exec() () at kernel/qapplication.cpp:2976
#26 0x0000000000432d4a in main(int, char**) (argc=4, argv=<optimized out>) at /build/plasma-workspace-kxRFE_/plasma-workspace-5.5.5.2/shell/main.cpp:181

Reported using DrKonqi