Bug 362979

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:

I switched away from a second session for over a day and when I switched back the screensaver had crashed. What may be relevant is that I had a different resolution set on the second session and the monitor that's connected is a 4k monitor using MST>

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 0x7f30ab447900 (LWP 9814))]

Thread 8 (Thread 0x7f3095dd6700 (LWP 9864)):
#0  0x00007f30a5b56e8d in poll () at ../sysdeps/unix/syscall-template.S:84
#1  0x00007f30a9c1bc62 in _xcb_conn_wait (__timeout=-1, __nfds=1, __fds=0x7f3095dd5bc0) at /usr/include/x86_64-linux-gnu/bits/poll2.h:46
#2  0x00007f30a9c1bc62 in _xcb_conn_wait (c=c@entry=0x1699730, cond=cond@entry=0x1699770, vector=vector@entry=0x0, count=count@entry=0x0) at ../../src/xcb_conn.c:459
#3  0x00007f30a9c1d8d7 in xcb_wait_for_event (c=0x1699730) at ../../src/xcb_in.c:693
#4  0x00007f3098556629 in QXcbEventReader::run() (this=0x16a7890) at qxcbconnection.cpp:1253
#5  0x00007f30a624c84e in QThreadPrivate::start(void*) (arg=0x16a7890) at thread/qthread_unix.cpp:331
#6  0x00007f30a53396fa in start_thread (arg=0x7f3095dd6700) at pthread_create.c:333
#7  0x00007f30a5b62b5d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

Thread 7 (Thread 0x7f308ed50700 (LWP 9866)):
#0  0x00007f30a2930a49 in g_mutex_lock (mutex=mutex@entry=0x7f3088000990) at /build/glib2.0-t9oPgV/glib2.0-2.48.0/./glib/gthread-posix.c:1338
#1  0x00007f30a28ebad1 in g_main_context_query (context=context@entry=0x7f3088000990, max_priority=2147483647, timeout=timeout@entry=0x7f308ed4fb74, fds=fds@entry=0x7f3088003070, n_fds=n_fds@entry=1) at /build/glib2.0-t9oPgV/glib2.0-2.48.0/./glib/gmain.c:3544
#2  0x00007f30a28ec297 in g_main_context_iterate (context=context@entry=0x7f3088000990, block=block@entry=1, dispatch=dispatch@entry=1, self=<optimized out>) at /build/glib2.0-t9oPgV/glib2.0-2.48.0/./glib/gmain.c:3822
#3  0x00007f30a28ec42c in g_main_context_iteration (context=0x7f3088000990, may_block=may_block@entry=1) at /build/glib2.0-t9oPgV/glib2.0-2.48.0/./glib/gmain.c:3901
#4  0x00007f30a6483a9b in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) (this=0x7f30880008c0, flags=...) at kernel/qeventdispatcher_glib.cpp:420
#5  0x00007f30a642adea in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) (this=this@entry=0x7f308ed4fca0, flags=..., flags@entry=...) at kernel/qeventloop.cpp:204
#6  0x00007f30a62478a4 in QThread::exec() (this=<optimized out>) at thread/qthread.cpp:503
#7  0x00007f30a8aef3c5 in  () at /usr/lib/x86_64-linux-gnu/libQt5Qml.so.5
#8  0x00007f30a624c84e in QThreadPrivate::start(void*) (arg=0x1798470) at thread/qthread_unix.cpp:331
#9  0x00007f30a53396fa in start_thread (arg=0x7f308ed50700) at pthread_create.c:333
#10 0x00007f30a5b62b5d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

Thread 6 (Thread 0x7f308458e700 (LWP 9867)):
#0  0x00007f30a5b56e8d in poll () at ../sysdeps/unix/syscall-template.S:84
#1  0x00007f30a28ec31c in g_main_context_iterate (priority=2147483647, n_fds=1, fds=0x7f307c002e70, timeout=<optimized out>, context=0x7f307c000990) at /build/glib2.0-t9oPgV/glib2.0-2.48.0/./glib/gmain.c:4135
#2  0x00007f30a28ec31c in g_main_context_iterate (context=context@entry=0x7f307c000990, 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  0x00007f30a28ec42c in g_main_context_iteration (context=0x7f307c000990, may_block=may_block@entry=1) at /build/glib2.0-t9oPgV/glib2.0-2.48.0/./glib/gmain.c:3901
#4  0x00007f30a6483a9b in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) (this=0x7f307c0008c0, flags=...) at kernel/qeventdispatcher_glib.cpp:420
#5  0x00007f30a642adea in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) (this=this@entry=0x7f308458dca0, flags=..., flags@entry=...) at kernel/qeventloop.cpp:204
#6  0x00007f30a62478a4 in QThread::exec() (this=<optimized out>) at thread/qthread.cpp:503
#7  0x00007f30a8aef3c5 in  () at /usr/lib/x86_64-linux-gnu/libQt5Qml.so.5
#8  0x00007f30a624c84e in QThreadPrivate::start(void*) (arg=0x18e3cf0) at thread/qthread_unix.cpp:331
#9  0x00007f30a53396fa in start_thread (arg=0x7f308458e700) at pthread_create.c:333
#10 0x00007f30a5b62b5d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

Thread 5 (Thread 0x7f3082402700 (LWP 9868)):
#0  0x00007f30a5b56e8d in poll () at ../sysdeps/unix/syscall-template.S:84
#1  0x00007f30a28ec31c in g_main_context_iterate (priority=2147483647, n_fds=1, fds=0x7f3074003070, timeout=<optimized out>, context=0x7f3074000990) at /build/glib2.0-t9oPgV/glib2.0-2.48.0/./glib/gmain.c:4135
#2  0x00007f30a28ec31c in g_main_context_iterate (context=context@entry=0x7f3074000990, 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  0x00007f30a28ec42c in g_main_context_iteration (context=0x7f3074000990, may_block=may_block@entry=1) at /build/glib2.0-t9oPgV/glib2.0-2.48.0/./glib/gmain.c:3901
#4  0x00007f30a6483a9b in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) (this=0x7f30740008c0, flags=...) at kernel/qeventdispatcher_glib.cpp:420
#5  0x00007f30a642adea in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) (this=this@entry=0x7f3082401ca0, flags=..., flags@entry=...) at kernel/qeventloop.cpp:204
#6  0x00007f30a62478a4 in QThread::exec() (this=<optimized out>) at thread/qthread.cpp:503
#7  0x00007f30a8aef3c5 in  () at /usr/lib/x86_64-linux-gnu/libQt5Qml.so.5
#8  0x00007f30a624c84e in QThreadPrivate::start(void*) (arg=0x1c54f90) at thread/qthread_unix.cpp:331
#9  0x00007f30a53396fa in start_thread (arg=0x7f3082402700) at pthread_create.c:333
#10 0x00007f30a5b62b5d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

Thread 4 (Thread 0x7f3080a91700 (LWP 9869)):
#0  0x00007f30a533f3a0 in pthread_cond_wait@@GLIBC_2.3.2 () at ../sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S:185
#1  0x00007f30aae94bd4 in  () at /usr/lib/x86_64-linux-gnu/libQt5Script.so.5
#2  0x00007f30aae94c19 in  () at /usr/lib/x86_64-linux-gnu/libQt5Script.so.5
#3  0x00007f30a53396fa in start_thread (arg=0x7f3080a91700) at pthread_create.c:333
#4  0x00007f30a5b62b5d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

Thread 3 (Thread 0x7f3079fb4700 (LWP 9870)):
#0  0x00007f30a5b56e8d in poll () at ../sysdeps/unix/syscall-template.S:84
#1  0x00007f30a28ec31c in g_main_context_iterate (priority=2147483647, n_fds=1, fds=0x7f2ff0003120, timeout=<optimized out>, context=0x7f2ff0000990) at /build/glib2.0-t9oPgV/glib2.0-2.48.0/./glib/gmain.c:4135
#2  0x00007f30a28ec31c in g_main_context_iterate (context=context@entry=0x7f2ff0000990, 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  0x00007f30a28ec42c in g_main_context_iteration (context=0x7f2ff0000990, may_block=may_block@entry=1) at /build/glib2.0-t9oPgV/glib2.0-2.48.0/./glib/gmain.c:3901
#4  0x00007f30a6483a9b in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) (this=0x7f2ff00008c0, flags=...) at kernel/qeventdispatcher_glib.cpp:420
#5  0x00007f30a642adea in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) (this=this@entry=0x7f3079fb3c50, flags=..., flags@entry=...) at kernel/qeventloop.cpp:204
#6  0x00007f30a62478a4 in QThread::exec() (this=<optimized out>) at thread/qthread.cpp:503
#7  0x00007f30a9475ed6 in  () at /usr/lib/x86_64-linux-gnu/libQt5Quick.so.5
#8  0x00007f30a624c84e in QThreadPrivate::start(void*) (arg=0x1f25050) at thread/qthread_unix.cpp:331
#9  0x00007f30a53396fa in start_thread (arg=0x7f3079fb4700) at pthread_create.c:333
#10 0x00007f30a5b62b5d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

Thread 2 (Thread 0x7f307905f700 (LWP 9871)):
[KCrash Handler]
#6  0x00007f30a5b0568d in __strstr_sse2_unaligned () at ../sysdeps/x86_64/multiarch/strstr-sse2-unaligned.S:40
#7  0x00007f30a94c8aca in QSGRenderContext::initialize(QOpenGLContext*) () at /usr/lib/x86_64-linux-gnu/libQt5Quick.so.5
#8  0x00007f30a94ec409 in  () at /usr/lib/x86_64-linux-gnu/libQt5Quick.so.5
#9  0x00007f30a624c84e in QThreadPrivate::start(void*) (arg=0x1f2b360) at thread/qthread_unix.cpp:331
#10 0x00007f30a53396fa in start_thread (arg=0x7f307905f700) at pthread_create.c:333
#11 0x00007f30a5b62b5d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

Thread 1 (Thread 0x7f30ab447900 (LWP 9814)):
#0  0x00007f30a533f3a0 in pthread_cond_wait@@GLIBC_2.3.2 () at ../sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S:185
#1  0x00007f30a624daeb in QWaitCondition::wait(QMutex*, unsigned long) (time=18446744073709551615, this=0x1ea5430) at thread/qwaitcondition_unix.cpp:136
#2  0x00007f30a624daeb in QWaitCondition::wait(QMutex*, unsigned long) (this=<optimized out>, mutex=0x1f2b3a0, time=18446744073709551615) at thread/qwaitcondition_unix.cpp:208
#3  0x00007f30a94e8bc6 in  () at /usr/lib/x86_64-linux-gnu/libQt5Quick.so.5
#4  0x00007f30a94eb09c in  () at /usr/lib/x86_64-linux-gnu/libQt5Quick.so.5
#5  0x00007f30a94eb733 in  () at /usr/lib/x86_64-linux-gnu/libQt5Quick.so.5
#6  0x00007f30a67782e5 in QWindow::event(QEvent*) (this=0x1e5d5b0, ev=<optimized out>) at kernel/qwindow.cpp:2060
#7  0x00007f30a951e871 in QQuickWindow::event(QEvent*) () at /usr/lib/x86_64-linux-gnu/libQt5Quick.so.5
#8  0x000000000043f206 in DesktopView::event(QEvent*) (this=0x1e5d5b0, e=0x7ffd33d4fbd0) at /build/plasma-workspace-kxRFE_/plasma-workspace-5.5.5.2/shell/desktopview.cpp:205
#9  0x00007f30a6f3005c in QApplicationPrivate::notify_helper(QObject*, QEvent*) (this=this@entry=0x1673460, receiver=receiver@entry=0x1e5d5b0, e=e@entry=0x7ffd33d4fbd0) at kernel/qapplication.cpp:3716
#10 0x00007f30a6f35516 in QApplication::notify(QObject*, QEvent*) (this=0x7ffd33d4fff0, receiver=0x1e5d5b0, e=0x7ffd33d4fbd0) at kernel/qapplication.cpp:3499
#11 0x00007f30a642d62b in QCoreApplication::notifyInternal(QObject*, QEvent*) (this=0x7ffd33d4fff0, receiver=receiver@entry=0x1e5d5b0, event=event@entry=0x7ffd33d4fbd0) at kernel/qcoreapplication.cpp:965
#12 0x00007f30a67704ec in QGuiApplicationPrivate::processExposeEvent(QWindowSystemInterfacePrivate::ExposeEvent*) (event=0x7ffd33d4fbd0, receiver=0x1e5d5b0) at ../../include/QtCore/../../src/corelib/kernel/qcoreapplication.h:227
#13 0x00007f30a67704ec in QGuiApplicationPrivate::processExposeEvent(QWindowSystemInterfacePrivate::ExposeEvent*) (e=0x1e762d0) at kernel/qguiapplication.cpp:2663
#14 0x00007f30a677125d in QGuiApplicationPrivate::processWindowSystemEvent(QWindowSystemInterfacePrivate::WindowSystemEvent*) (e=e@entry=0x1e762d0) at kernel/qguiapplication.cpp:1658
#15 0x00007f30a6754f38 in QWindowSystemInterface::sendWindowSystemEvents(QFlags<QEventLoop::ProcessEventsFlag>) (flags=...) at kernel/qwindowsysteminterface.cpp:625
#16 0x00007f3098587f10 in userEventSourceDispatch(GSource*, GSourceFunc, gpointer) (source=<optimized out>) at eventdispatchers/qeventdispatcher_glib.cpp:70
#17 0x00007f30a28ec127 in g_main_context_dispatch (context=0x7f3090001710) at /build/glib2.0-t9oPgV/glib2.0-2.48.0/./glib/gmain.c:3154
#18 0x00007f30a28ec127 in g_main_context_dispatch (context=context@entry=0x7f3090001710) at /build/glib2.0-t9oPgV/glib2.0-2.48.0/./glib/gmain.c:3769
#19 0x00007f30a28ec380 in g_main_context_iterate (context=context@entry=0x7f3090001710, 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 0x00007f30a28ec42c in g_main_context_iteration (context=0x7f3090001710, may_block=may_block@entry=1) at /build/glib2.0-t9oPgV/glib2.0-2.48.0/./glib/gmain.c:3901
#21 0x00007f30a6483a7f in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) (this=0x16cca40, flags=...) at kernel/qeventdispatcher_glib.cpp:418
#22 0x00007f30a642adea in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) (this=this@entry=0x7ffd33d4fe90, flags=..., flags@entry=...) at kernel/qeventloop.cpp:204
#23 0x00007f30a6432e8c in QCoreApplication::exec() () at kernel/qcoreapplication.cpp:1229
#24 0x00007f30a6766c3c in QGuiApplication::exec() () at kernel/qguiapplication.cpp:1542
#25 0x00007f30a6f2c495 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