Bug 365069

Summary:	Plasma crash when unplugging or plugging screen
Product:	[Plasma] KScreen	Reporter:	Philipp A. <flying-sheep>
Component:	common	Assignee:	Sebastian Kügler <sebas>
Status:	RESOLVED FIXED
Severity:	crash
Priority:	NOR
Version First Reported In:	5.6.5
Target Milestone:	---
Platform:	Arch Linux
OS:	Linux
Latest Commit:		Version Fixed/Implemented In:
Sentry Crash Report:

Description Philipp A. 2016-07-04 11:13:38 UTC

when umplugging my external screen, the laptop screen goes black instead of staying like it is (but switching to TTYs still works)

either un unplugging or plugging, plasma dies, and only restarts once i re-plug the screen

since i’m on arch and nobody bothers to package the debug symbols there, here my mutilated backtrace:

Application: Plasma (plasmashell), signal: Segmentation fault
Using host libthread_db library "/usr/lib/libthread_db.so.1".
[Current thread is 1 (Thread 0x7f230259e800 (LWP 10263))]

Thread 9 (Thread 0x7f22356b0700 (LWP 10275)):
#0  0x00007f22fba5b72d in read () from /usr/lib/libc.so.6
#1  0x00007f22f6b5cc80 in ?? () from /usr/lib/libglib-2.0.so.0
#2  0x00007f22f6b19ab4 in g_main_context_check () from /usr/lib/libglib-2.0.so.0
#3  0x00007f22f6b19f74 in ?? () from /usr/lib/libglib-2.0.so.0
#4  0x00007f22f6b1a0ec in g_main_context_iteration () from /usr/lib/libglib-2.0.so.0
#5  0x00007f22fc38459b in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/libQt5Core.so.5
#6  0x00007f22fc32e0da in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/libQt5Core.so.5
#7  0x00007f22fc1510f3 in QThread::exec() () from /usr/lib/libQt5Core.so.5
#8  0x00007f2237bb80d7 in KCupsConnection::run() () from /usr/lib/libkcupslib.so
#9  0x00007f22fc155d78 in ?? () from /usr/lib/libQt5Core.so.5
#10 0x00007f22fb263484 in start_thread () from /usr/lib/libpthread.so.0
#11 0x00007f22fba686dd in clone () from /usr/lib/libc.so.6

Thread 8 (Thread 0x7f2243fff700 (LWP 10270)):
#0  0x00007f22f6b5e029 in g_mutex_lock () from /usr/lib/libglib-2.0.so.0
#1  0x00007f22f6b19ed0 in ?? () from /usr/lib/libglib-2.0.so.0
#2  0x00007f22f6b1a0ec in g_main_context_iteration () from /usr/lib/libglib-2.0.so.0
#3  0x00007f22fc38459b in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/libQt5Core.so.5
#4  0x00007f22fc32e0da in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/libQt5Core.so.5
#5  0x00007f22fc1510f3 in QThread::exec() () from /usr/lib/libQt5Core.so.5
#6  0x00007f230004f8a6 in ?? () from /usr/lib/libQt5Quick.so.5
#7  0x00007f22fc155d78 in ?? () from /usr/lib/libQt5Core.so.5
#8  0x00007f22fb263484 in start_thread () from /usr/lib/libpthread.so.0
#9  0x00007f22fba686dd in clone () from /usr/lib/libc.so.6

Thread 7 (Thread 0x7f22cafba700 (LWP 10269)):
#0  0x00007f22fb2690af in pthread_cond_wait@@GLIBC_2.3.2 () from /usr/lib/libpthread.so.0
#1  0x00007f2301d2cac4 in ?? () from /usr/lib/libQt5Script.so.5
#2  0x00007f2301d2cb09 in ?? () from /usr/lib/libQt5Script.so.5
#3  0x00007f22fb263484 in start_thread () from /usr/lib/libpthread.so.0
#4  0x00007f22fba686dd in clone () from /usr/lib/libc.so.6

Thread 6 (Thread 0x7f22d09bb700 (LWP 10268)):
#0  0x00007f22fba5f6cd in poll () from /usr/lib/libc.so.6
#1  0x00007f22f6b19fd6 in ?? () from /usr/lib/libglib-2.0.so.0
#2  0x00007f22f6b1a0ec in g_main_context_iteration () from /usr/lib/libglib-2.0.so.0
#3  0x00007f22fc38459b in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/libQt5Core.so.5
#4  0x00007f22fc32e0da in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/libQt5Core.so.5
#5  0x00007f22fc1510f3 in QThread::exec() () from /usr/lib/libQt5Core.so.5
#6  0x00007f22ff4b1445 in ?? () from /usr/lib/libQt5Qml.so.5
#7  0x00007f22fc155d78 in ?? () from /usr/lib/libQt5Core.so.5
#8  0x00007f22fb263484 in start_thread () from /usr/lib/libpthread.so.0
#9  0x00007f22fba686dd in clone () from /usr/lib/libc.so.6

Thread 5 (Thread 0x7f22d2560700 (LWP 10267)):
#0  0x00007f22fc14cf49 in QMutex::lock() () from /usr/lib/libQt5Core.so.5
#1  0x00007f22fc383d0f in ?? () from /usr/lib/libQt5Core.so.5
#2  0x00007f22f6b1950d in g_main_context_prepare () from /usr/lib/libglib-2.0.so.0
#3  0x00007f22f6b19efb in ?? () from /usr/lib/libglib-2.0.so.0
#4  0x00007f22f6b1a0ec in g_main_context_iteration () from /usr/lib/libglib-2.0.so.0
#5  0x00007f22fc38459b in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/libQt5Core.so.5
#6  0x00007f22fc32e0da in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/libQt5Core.so.5
#7  0x00007f22fc1510f3 in QThread::exec() () from /usr/lib/libQt5Core.so.5
#8  0x00007f22ff4b1445 in ?? () from /usr/lib/libQt5Qml.so.5
#9  0x00007f22fc155d78 in ?? () from /usr/lib/libQt5Core.so.5
#10 0x00007f22fb263484 in start_thread () from /usr/lib/libpthread.so.0
#11 0x00007f22fba686dd in clone () from /usr/lib/libc.so.6

Thread 4 (Thread 0x7f22e3bd9700 (LWP 10266)):
#0  0x00007f22fc382807 in QTimerInfoList::timerWait(timespec&) () from /usr/lib/libQt5Core.so.5
#1  0x00007f22fc383b6e in ?? () from /usr/lib/libQt5Core.so.5
#2  0x00007f22f6b1950d in g_main_context_prepare () from /usr/lib/libglib-2.0.so.0
#3  0x00007f22f6b19efb in ?? () from /usr/lib/libglib-2.0.so.0
#4  0x00007f22f6b1a0ec in g_main_context_iteration () from /usr/lib/libglib-2.0.so.0
#5  0x00007f22fc38459b in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/libQt5Core.so.5
#6  0x00007f22fc32e0da in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/libQt5Core.so.5
#7  0x00007f22fc1510f3 in QThread::exec() () from /usr/lib/libQt5Core.so.5
#8  0x00007f22ff4b1445 in ?? () from /usr/lib/libQt5Qml.so.5
#9  0x00007f22fc155d78 in ?? () from /usr/lib/libQt5Core.so.5
#10 0x00007f22fb263484 in start_thread () from /usr/lib/libpthread.so.0
#11 0x00007f22fba686dd in clone () from /usr/lib/libc.so.6

Thread 3 (Thread 0x7f22e95bd700 (LWP 10265)):
#0  0x00007f22fba5b72d in read () from /usr/lib/libc.so.6
#1  0x00007f22f6b5cc80 in ?? () from /usr/lib/libglib-2.0.so.0
#2  0x00007f22f6b19ab4 in g_main_context_check () from /usr/lib/libglib-2.0.so.0
#3  0x00007f22f6b19f74 in ?? () from /usr/lib/libglib-2.0.so.0
#4  0x00007f22f6b1a0ec in g_main_context_iteration () from /usr/lib/libglib-2.0.so.0
#5  0x00007f22fc38459b in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/libQt5Core.so.5
#6  0x00007f22fc32e0da in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/libQt5Core.so.5
#7  0x00007f22fc1510f3 in QThread::exec() () from /usr/lib/libQt5Core.so.5
#8  0x00007f22fd0d6e75 in ?? () from /usr/lib/libQt5DBus.so.5
#9  0x00007f22fc155d78 in ?? () from /usr/lib/libQt5Core.so.5
#10 0x00007f22fb263484 in start_thread () from /usr/lib/libpthread.so.0
#11 0x00007f22fba686dd in clone () from /usr/lib/libc.so.6

Thread 2 (Thread 0x7f22eb1eb700 (LWP 10264)):
#0  0x00007f22fba5f6cd in poll () from /usr/lib/libc.so.6
#1  0x00007f2300a298e0 in ?? () from /usr/lib/libxcb.so.1
#2  0x00007f2300a2b679 in xcb_wait_for_event () from /usr/lib/libxcb.so.1
#3  0x00007f22ecb10469 in ?? () from /usr/lib/libQt5XcbQpa.so.5
#4  0x00007f22fc155d78 in ?? () from /usr/lib/libQt5Core.so.5
#5  0x00007f22fb263484 in start_thread () from /usr/lib/libpthread.so.0
#6  0x00007f22fba686dd in clone () from /usr/lib/libc.so.6

Thread 1 (Thread 0x7f230259e800 (LWP 10263)):
[KCrash Handler]
#5  0x00007f230077d770 in Plasma::Applet::actions() const () from /usr/lib/libKF5Plasma.so.5
#6  0x00000000004461c3 in ?? ()
#7  0x000000000044633f in ?? ()
#8  0x00007f22fc35b85e in QMetaObject::activate(QObject*, int, int, void**) () from /usr/lib/libQt5Core.so.5
#9  0x00007f230145f003 in KScreen::Output::apply(QSharedPointer<KScreen::Output> const&) () from /usr/lib/libKF5Screen.so.7
#10 0x00007f2301440354 in KScreen::Config::apply(QSharedPointer<KScreen::Config> const&) () from /usr/lib/libKF5Screen.so.7
#11 0x00007f230144c826 in KScreen::ConfigMonitor::Private::updateConfigs(QSharedPointer<KScreen::Config> const&) () from /usr/lib/libKF5Screen.so.7
#12 0x00007f230144e9a9 in KScreen::ConfigMonitor::Private::edidReady(QDBusPendingCallWatcher*) () from /usr/lib/libKF5Screen.so.7
#13 0x00007f22fc35b85e in QMetaObject::activate(QObject*, int, int, void**) () from /usr/lib/libQt5Core.so.5
#14 0x00007f22fd12e6df in QDBusPendingCallWatcher::finished(QDBusPendingCallWatcher*) () from /usr/lib/libQt5DBus.so.5
#15 0x00007f22fd12e7d8 in ?? () from /usr/lib/libQt5DBus.so.5
#16 0x00007f22fc35c349 in QObject::event(QEvent*) () from /usr/lib/libQt5Core.so.5
#17 0x00007f22fd49fe3c in QApplicationPrivate::notify_helper(QObject*, QEvent*) () from /usr/lib/libQt5Widgets.so.5
#18 0x00007f22fd4a75b1 in QApplication::notify(QObject*, QEvent*) () from /usr/lib/libQt5Widgets.so.5
#19 0x00007f22fc32fc80 in QCoreApplication::notifyInternal2(QObject*, QEvent*) () from /usr/lib/libQt5Core.so.5
#20 0x00007f22fc3323fd in QCoreApplicationPrivate::sendPostedEvents(QObject*, int, QThreadData*) () from /usr/lib/libQt5Core.so.5
#21 0x00007f22fc384173 in ?? () from /usr/lib/libQt5Core.so.5
#22 0x00007f22f6b19dd7 in g_main_context_dispatch () from /usr/lib/libglib-2.0.so.0
#23 0x00007f22f6b1a040 in ?? () from /usr/lib/libglib-2.0.so.0
#24 0x00007f22f6b1a0ec in g_main_context_iteration () from /usr/lib/libglib-2.0.so.0
#25 0x00007f22fc38457f in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/libQt5Core.so.5
#26 0x00007f22fc32e0da in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/libQt5Core.so.5
#27 0x00007f22fc3365cc in QCoreApplication::exec() () from /usr/lib/libQt5Core.so.5
#28 0x000000000041c17c in ?? ()
#29 0x00007f22fb9a1741 in __libc_start_main () from /usr/lib/libc.so.6
#30 0x000000000041c2e9 in _start ()


Reproducible: Always

Comment 1 Sebastian Kügler 2016-07-04 11:21:53 UTC

Hi Phil,

Thanks for the bugreport!

In Plasma 5.7, kscreen isn't used in plasmashell anymore. Please test with 5.7 and see if that improves the situation.

I'm closing this bug since the backtrace is useless and will definitely look different with 5.7. If problems persist, please open a new report.