Application: plasmashell (5.5.5)

Qt Version: 5.5.1
Operating System: Linux 4.4.0-51-generic x86_64
Distribution: Ubuntu 16.04.1 LTS

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

I locked the machine and another user created a new session and logged in to her account, then she later locked the machine and I switched back to my session, and unlocked it to a black screen and a crash reporting assistant.

-- 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 0x7fef751b88c0 (LWP 31774))]

Thread 8 (Thread 0x7feeb3015700 (LWP 31785)):
[KCrash Handler]
#6  0x00007fef6f89450d in __strstr_sse2_unaligned () at ../sysdeps/x86_64/multiarch/strstr-sse2-unaligned.S:40
#7  0x00007fef73257aca in QSGRenderContext::initialize(QOpenGLContext*) () at /usr/lib/x86_64-linux-gnu/libQt5Quick.so.5
#8  0x00007fef7327b409 in  () at /usr/lib/x86_64-linux-gnu/libQt5Quick.so.5
#9  0x00007fef6ffdb7be in QThreadPrivate::start(void*) (arg=0x1219b00) at thread/qthread_unix.cpp:331
#10 0x00007fef6f0c870a in start_thread (arg=0x7feeb3015700) at pthread_create.c:333
#11 0x00007fef6f8f182d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

Thread 7 (Thread 0x7fef3ce22700 (LWP 31784)):
#0  0x00007fef6f8e5b5d in poll () at ../sysdeps/unix/syscall-template.S:84
#1  0x00007fef6c67c39c in g_main_context_iterate (priority=2147483647, n_fds=1, fds=0x7feeb4002e20, timeout=<optimized out>, context=0x7feeb4000990) at /build/glib2.0-7IO_Yw/glib2.0-2.48.1/./glib/gmain.c:4135
#2  0x00007fef6c67c39c in g_main_context_iterate (context=context@entry=0x7feeb4000990, block=block@entry=1, dispatch=dispatch@entry=1, self=<optimized out>) at /build/glib2.0-7IO_Yw/glib2.0-2.48.1/./glib/gmain.c:3835
#3  0x00007fef6c67c4ac in g_main_context_iteration (context=0x7feeb4000990, may_block=may_block@entry=1) at /build/glib2.0-7IO_Yw/glib2.0-2.48.1/./glib/gmain.c:3901
#4  0x00007fef702127eb in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) (this=0x7feeb40008c0, flags=...) at kernel/qeventdispatcher_glib.cpp:420
#5  0x00007fef701b9b4a in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) (this=this@entry=0x7fef3ce21c90, flags=..., flags@entry=...) at kernel/qeventloop.cpp:204
#6  0x00007fef6ffd6834 in QThread::exec() (this=<optimized out>) at thread/qthread.cpp:503
#7  0x00007fef73204ed6 in  () at /usr/lib/x86_64-linux-gnu/libQt5Quick.so.5
#8  0x00007fef6ffdb7be in QThreadPrivate::start(void*) (arg=0x12f2090) at thread/qthread_unix.cpp:331
#9  0x00007fef6f0c870a in start_thread (arg=0x7fef3ce22700) at pthread_create.c:333
#10 0x00007fef6f8f182d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

Thread 6 (Thread 0x7fef3f7bc700 (LWP 31782)):
#0  0x00007fef6f0ce3b0 in pthread_cond_wait@@GLIBC_2.3.2 () at ../sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S:185
#1  0x00007fef74c23bd4 in  () at /usr/lib/x86_64-linux-gnu/libQt5Script.so.5
#2  0x00007fef74c23c19 in  () at /usr/lib/x86_64-linux-gnu/libQt5Script.so.5
#3  0x00007fef6f0c870a in start_thread (arg=0x7fef3f7bc700) at pthread_create.c:333
#4  0x00007fef6f8f182d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

Thread 5 (Thread 0x7fef4515d700 (LWP 31781)):
#0  0x00007fef6f8e169d in read () at ../sysdeps/unix/syscall-template.S:84
#1  0x00007fef6c6bf740 in g_wakeup_acknowledge (__nbytes=16, __buf=0x7fef4515cae0, __fd=<optimized out>) at /usr/include/x86_64-linux-gnu/bits/unistd.h:44
#2  0x00007fef6c6bf740 in g_wakeup_acknowledge (wakeup=0x7fef40002720) at /build/glib2.0-7IO_Yw/glib2.0-2.48.1/./glib/gwakeup.c:210
#3  0x00007fef6c67be84 in g_main_context_check (context=context@entry=0x7fef38000990, max_priority=2147483647, fds=fds@entry=0x7fef38002e70, n_fds=n_fds@entry=1) at /build/glib2.0-7IO_Yw/glib2.0-2.48.1/./glib/gmain.c:3632
#4  0x00007fef6c67c340 in g_main_context_iterate (context=context@entry=0x7fef38000990, block=block@entry=1, dispatch=dispatch@entry=1, self=<optimized out>) at /build/glib2.0-7IO_Yw/glib2.0-2.48.1/./glib/gmain.c:3837
#5  0x00007fef6c67c4ac in g_main_context_iteration (context=0x7fef38000990, may_block=may_block@entry=1) at /build/glib2.0-7IO_Yw/glib2.0-2.48.1/./glib/gmain.c:3901
#6  0x00007fef702127eb in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) (this=0x7fef380008c0, flags=...) at kernel/qeventdispatcher_glib.cpp:420
#7  0x00007fef701b9b4a in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) (this=this@entry=0x7fef4515cce0, flags=..., flags@entry=...) at kernel/qeventloop.cpp:204
#8  0x00007fef6ffd6834 in QThread::exec() (this=<optimized out>) at thread/qthread.cpp:503
#9  0x00007fef7287e3c5 in  () at /usr/lib/x86_64-linux-gnu/libQt5Qml.so.5
#10 0x00007fef6ffdb7be in QThreadPrivate::start(void*) (arg=0xfab660) at thread/qthread_unix.cpp:331
#11 0x00007fef6f0c870a in start_thread (arg=0x7fef4515d700) at pthread_create.c:333
#12 0x00007fef6f8f182d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

Thread 4 (Thread 0x7fef46fed700 (LWP 31780)):
#0  0x00007fef6c6c0ac9 in g_mutex_lock (mutex=mutex@entry=0x7fef40000990) at /build/glib2.0-7IO_Yw/glib2.0-2.48.1/./glib/gthread-posix.c:1335
#1  0x00007fef6c67bb51 in g_main_context_query (context=context@entry=0x7fef40000990, max_priority=2147483647, timeout=timeout@entry=0x7fef46fecbb4, fds=fds@entry=0x7fef40003270, n_fds=n_fds@entry=1) at /build/glib2.0-7IO_Yw/glib2.0-2.48.1/./glib/gmain.c:3544
#2  0x00007fef6c67c317 in g_main_context_iterate (context=context@entry=0x7fef40000990, block=block@entry=1, dispatch=dispatch@entry=1, self=<optimized out>) at /build/glib2.0-7IO_Yw/glib2.0-2.48.1/./glib/gmain.c:3822
#3  0x00007fef6c67c4ac in g_main_context_iteration (context=0x7fef40000990, may_block=may_block@entry=1) at /build/glib2.0-7IO_Yw/glib2.0-2.48.1/./glib/gmain.c:3901
#4  0x00007fef702127eb in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) (this=0x7fef400008c0, flags=...) at kernel/qeventdispatcher_glib.cpp:420
#5  0x00007fef701b9b4a in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) (this=this@entry=0x7fef46fecce0, flags=..., flags@entry=...) at kernel/qeventloop.cpp:204
#6  0x00007fef6ffd6834 in QThread::exec() (this=<optimized out>) at thread/qthread.cpp:503
#7  0x00007fef7287e3c5 in  () at /usr/lib/x86_64-linux-gnu/libQt5Qml.so.5
#8  0x00007fef6ffdb7be in QThreadPrivate::start(void*) (arg=0xed9100) at thread/qthread_unix.cpp:331
#9  0x00007fef6f0c870a in start_thread (arg=0x7fef46fed700) at pthread_create.c:333
#10 0x00007fef6f8f182d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

Thread 3 (Thread 0x7fef54213700 (LWP 31779)):
#0  0x00007fef6f8e5b5d in poll () at ../sysdeps/unix/syscall-template.S:84
#1  0x00007fef6c67c39c in g_main_context_iterate (priority=2147483647, n_fds=1, fds=0x7fef4c003270, timeout=<optimized out>, context=0x7fef4c000990) at /build/glib2.0-7IO_Yw/glib2.0-2.48.1/./glib/gmain.c:4135
#2  0x00007fef6c67c39c in g_main_context_iterate (context=context@entry=0x7fef4c000990, block=block@entry=1, dispatch=dispatch@entry=1, self=<optimized out>) at /build/glib2.0-7IO_Yw/glib2.0-2.48.1/./glib/gmain.c:3835
#3  0x00007fef6c67c4ac in g_main_context_iteration (context=0x7fef4c000990, may_block=may_block@entry=1) at /build/glib2.0-7IO_Yw/glib2.0-2.48.1/./glib/gmain.c:3901
#4  0x00007fef702127eb in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) (this=0x7fef4c0008c0, flags=...) at kernel/qeventdispatcher_glib.cpp:420
#5  0x00007fef701b9b4a in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) (this=this@entry=0x7fef54212ce0, flags=..., flags@entry=...) at kernel/qeventloop.cpp:204
#6  0x00007fef6ffd6834 in QThread::exec() (this=<optimized out>) at thread/qthread.cpp:503
#7  0x00007fef7287e3c5 in  () at /usr/lib/x86_64-linux-gnu/libQt5Qml.so.5
#8  0x00007fef6ffdb7be in QThreadPrivate::start(void*) (arg=0xb989e0) at thread/qthread_unix.cpp:331
#9  0x00007fef6f0c870a in start_thread (arg=0x7fef54213700) at pthread_create.c:333
#10 0x00007fef6f8f182d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

Thread 2 (Thread 0x7fef61410700 (LWP 31777)):
#0  0x00007fef6f8e5b5d in poll () at ../sysdeps/unix/syscall-template.S:84
#1  0x00007fef739aac62 in  () at /usr/lib/x86_64-linux-gnu/libxcb.so.1
#2  0x00007fef739ac8d7 in xcb_wait_for_event () at /usr/lib/x86_64-linux-gnu/libxcb.so.1
#3  0x00007fef63b90629 in QXcbEventReader::run() (this=0x9c7630) at qxcbconnection.cpp:1253
#4  0x00007fef6ffdb7be in QThreadPrivate::start(void*) (arg=0x9c7630) at thread/qthread_unix.cpp:331
#5  0x00007fef6f0c870a in start_thread (arg=0x7fef61410700) at pthread_create.c:333
#6  0x00007fef6f8f182d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

Thread 1 (Thread 0x7fef751b88c0 (LWP 31774)):
#0  0x00007fef6f0ce3b0 in pthread_cond_wait@@GLIBC_2.3.2 () at ../sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S:185
#1  0x00007fef6ffdca5b in QWaitCondition::wait(QMutex*, unsigned long) (time=18446744073709551615, this=0x11c0df0) at thread/qwaitcondition_unix.cpp:136
#2  0x00007fef6ffdca5b in QWaitCondition::wait(QMutex*, unsigned long) (this=<optimized out>, mutex=0x1219b40, time=18446744073709551615) at thread/qwaitcondition_unix.cpp:208
#3  0x00007fef73277bc6 in  () at /usr/lib/x86_64-linux-gnu/libQt5Quick.so.5
#4  0x00007fef7327a09c in  () at /usr/lib/x86_64-linux-gnu/libQt5Quick.so.5
#5  0x00007fef7327a733 in  () at /usr/lib/x86_64-linux-gnu/libQt5Quick.so.5
#6  0x00007fef705072b5 in QWindow::event(QEvent*) (this=0x11be9e0, ev=<optimized out>) at kernel/qwindow.cpp:2060
#7  0x00007fef732ad871 in QQuickWindow::event(QEvent*) () at /usr/lib/x86_64-linux-gnu/libQt5Quick.so.5
#8  0x000000000043f206 in DesktopView::event(QEvent*) (this=0x11be9e0, e=0x7fffaed6bf70) at /build/plasma-workspace-kxRFE_/plasma-workspace-5.5.5.2/shell/desktopview.cpp:205
#9  0x00007fef70cbf05c in QApplicationPrivate::notify_helper(QObject*, QEvent*) (this=this@entry=0x9aa3a0, receiver=receiver@entry=0x11be9e0, e=e@entry=0x7fffaed6bf70) at kernel/qapplication.cpp:3716
#10 0x00007fef70cc4516 in QApplication::notify(QObject*, QEvent*) (this=0x7fffaed6c390, receiver=0x11be9e0, e=0x7fffaed6bf70) at kernel/qapplication.cpp:3499
#11 0x00007fef701bc38b in QCoreApplication::notifyInternal(QObject*, QEvent*) (this=0x7fffaed6c390, receiver=receiver@entry=0x11be9e0, event=event@entry=0x7fffaed6bf70) at kernel/qcoreapplication.cpp:965
#12 0x00007fef704ff4ac in QGuiApplicationPrivate::processExposeEvent(QWindowSystemInterfacePrivate::ExposeEvent*) (event=0x7fffaed6bf70, receiver=0x11be9e0) at ../../include/QtCore/../../src/corelib/kernel/qcoreapplication.h:227
#13 0x00007fef704ff4ac in QGuiApplicationPrivate::processExposeEvent(QWindowSystemInterfacePrivate::ExposeEvent*) (e=0x11a0a30) at kernel/qguiapplication.cpp:2663
#14 0x00007fef7050021d in QGuiApplicationPrivate::processWindowSystemEvent(QWindowSystemInterfacePrivate::WindowSystemEvent*) (e=e@entry=0x11a0a30) at kernel/qguiapplication.cpp:1658
#15 0x00007fef704e3f08 in QWindowSystemInterface::sendWindowSystemEvents(QFlags<QEventLoop::ProcessEventsFlag>) (flags=...) at kernel/qwindowsysteminterface.cpp:625
#16 0x00007fef63bc2060 in userEventSourceDispatch(GSource*, GSourceFunc, gpointer) (source=<optimized out>) at eventdispatchers/qeventdispatcher_glib.cpp:70
#17 0x00007fef6c67c1a7 in g_main_context_dispatch (context=0x7fef5c0016f0) at /build/glib2.0-7IO_Yw/glib2.0-2.48.1/./glib/gmain.c:3154
#18 0x00007fef6c67c1a7 in g_main_context_dispatch (context=context@entry=0x7fef5c0016f0) at /build/glib2.0-7IO_Yw/glib2.0-2.48.1/./glib/gmain.c:3769
#19 0x00007fef6c67c400 in g_main_context_iterate (context=context@entry=0x7fef5c0016f0, block=block@entry=1, dispatch=dispatch@entry=1, self=<optimized out>) at /build/glib2.0-7IO_Yw/glib2.0-2.48.1/./glib/gmain.c:3840
#20 0x00007fef6c67c4ac in g_main_context_iteration (context=0x7fef5c0016f0, may_block=may_block@entry=1) at /build/glib2.0-7IO_Yw/glib2.0-2.48.1/./glib/gmain.c:3901
#21 0x00007fef702127cf in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) (this=0xa9eda0, flags=...) at kernel/qeventdispatcher_glib.cpp:418
#22 0x00007fef701b9b4a in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) (this=this@entry=0x7fffaed6c230, flags=..., flags@entry=...) at kernel/qeventloop.cpp:204
#23 0x00007fef701c1bec in QCoreApplication::exec() () at kernel/qcoreapplication.cpp:1229
#24 0x00007fef704f5bfc in QGuiApplication::exec() () at kernel/qguiapplication.cpp:1542
#25 0x00007fef70cbb495 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