Application: kwin_x11 (5.3.2) Qt Version: 5.4.2 Operating System: Linux 4.1.4-200.fc22.x86_64 x86_64 Distribution (Platform): Fedora RPMs -- Information about the crash: - What I was doing when the application crashed: On Lenovo T450s connected to external monitor, both 1920x1080, after logging in from a screen lock KWin always segfaults, panel disappears, etc. Applications (firefox, etc.) cntinue to work. Restarting from the popup window that inform of the crash is usually possible. The crash can be reproduced every time. -- Backtrace: Application: KWin (kwin_x11), signal: Segmentation fault Using host libthread_db library "/lib64/libthread_db.so.1". [Current thread is 1 (Thread 0x7f1a90cfe900 (LWP 7153))] Thread 4 (Thread 0x7f1a6615e700 (LWP 7173)): #0 0x00007f1a85b5a063 in select () from /lib64/libc.so.6 #1 0x00007f1a8709e1ff in qt_safe_select(int, fd_set*, fd_set*, fd_set*, timespec const*) () from /lib64/libQt5Core.so.5 #2 0x00007f1a8709fcfe in QEventDispatcherUNIXPrivate::doSelect(QFlags<QEventLoop::ProcessEventsFlag>, timespec*) () from /lib64/libQt5Core.so.5 #3 0x00007f1a870a022e in QEventDispatcherUNIX::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /lib64/libQt5Core.so.5 #4 0x00007f1a87048eba in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () from /lib64/libQt5Core.so.5 #5 0x00007f1a86e66f54 in QThread::exec() () from /lib64/libQt5Core.so.5 #6 0x00007f1a8e8e3955 in QQmlThreadPrivate::run() () from /lib64/libQt5Qml.so.5 #7 0x00007f1a86e6be3e in QThreadPrivate::start(void*) () from /lib64/libQt5Core.so.5 #8 0x00007f1a8a131555 in start_thread () from /lib64/libpthread.so.0 #9 0x00007f1a85b63b9d in clone () from /lib64/libc.so.6 Thread 3 (Thread 0x7f1a5de5f700 (LWP 7213)): #0 0x00007f1a8a136540 in pthread_cond_wait@@GLIBC_2.3.2 () from /lib64/libpthread.so.0 #1 0x00007f1a8faa3474 in QTWTF::TCMalloc_PageHeap::scavengerThread() () from /lib64/libQt5Script.so.5 #2 0x00007f1a8faa34b9 in QTWTF::TCMalloc_PageHeap::runScavengerThread(void*) () from /lib64/libQt5Script.so.5 #3 0x00007f1a8a131555 in start_thread () from /lib64/libpthread.so.0 #4 0x00007f1a85b63b9d in clone () from /lib64/libc.so.6 Thread 2 (Thread 0x7f1a5e660700 (LWP 7645)): #0 0x00007f1a85b5a063 in select () from /lib64/libc.so.6 #1 0x00007f1a8709e1ff in qt_safe_select(int, fd_set*, fd_set*, fd_set*, timespec const*) () from /lib64/libQt5Core.so.5 #2 0x00007f1a8709fcfe in QEventDispatcherUNIXPrivate::doSelect(QFlags<QEventLoop::ProcessEventsFlag>, timespec*) () from /lib64/libQt5Core.so.5 #3 0x00007f1a870a022e in QEventDispatcherUNIX::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /lib64/libQt5Core.so.5 #4 0x00007f1a87048eba in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () from /lib64/libQt5Core.so.5 #5 0x00007f1a86e66f54 in QThread::exec() () from /lib64/libQt5Core.so.5 #6 0x00007f1a8e8e3955 in QQmlThreadPrivate::run() () from /lib64/libQt5Qml.so.5 #7 0x00007f1a86e6be3e in QThreadPrivate::start(void*) () from /lib64/libQt5Core.so.5 #8 0x00007f1a8a131555 in start_thread () from /lib64/libpthread.so.0 #9 0x00007f1a85b63b9d in clone () from /lib64/libc.so.6 Thread 1 (Thread 0x7f1a90cfe900 (LWP 7153)): [KCrash Handler] #5 0x00007f1a87590b04 in QScreen::devicePixelRatio() const () from /lib64/libQt5Gui.so.5 #6 0x00007f1a8ed7e31e in QSGTextMaskMaterial::init(QFontEngine::GlyphFormat) () from /lib64/libQt5Quick.so.5 #7 0x00007f1a8ed7ef7e in QSGStyledTextMaterial::QSGStyledTextMaterial(QRawFont const&) () from /lib64/libQt5Quick.so.5 #8 0x00007f1a8ed7d08d in QSGDefaultGlyphNode::update() () from /lib64/libQt5Quick.so.5 #9 0x00007f1a8ee096e7 in QQuickTextNode::addGlyphs(QPointF const&, QGlyphRun const&, QColor const&, QQuickText::TextStyle, QColor const&, QSGNode*) () from /lib64/libQt5Quick.so.5 #10 0x00007f1a8ee0cd93 in QQuickTextNodeEngine::addToSceneGraph(QQuickTextNode*, QQuickText::TextStyle, QColor const&) () from /lib64/libQt5Quick.so.5 #11 0x00007f1a8ee0a5a7 in QQuickTextNode::addTextLayout(QPointF const&, QTextLayout*, QColor const&, QQuickText::TextStyle, QColor const&, QColor const&, QColor const&, QColor const&, int, int, int, int) () from /lib64/libQt5Quick.so.5 #12 0x00007f1a8ee08d48 in QQuickText::updatePaintNode(QSGNode*, QQuickItem::UpdatePaintNodeData*) () from /lib64/libQt5Quick.so.5 #13 0x00007f1a8edc1647 in QQuickWindowPrivate::updateDirtyNode(QQuickItem*) () from /lib64/libQt5Quick.so.5 #14 0x00007f1a8edc20eb in QQuickWindowPrivate::updateDirtyNodes() () from /lib64/libQt5Quick.so.5 #15 0x00007f1a8edc275e in QQuickWindowPrivate::syncSceneGraph() () from /lib64/libQt5Quick.so.5 #16 0x00007f1a8eea2fca in QQuickRenderControl::sync() () from /lib64/libQt5Quick.so.5 #17 0x00007f1a6617bbd9 in QtPrivate::QFunctorSlotObject<Aurorae::Decoration::init()::{lambda()#8}, 0, QtPrivate::List<>, void>::impl(int, QtPrivate::QSlotObjectBase*, QObject*, void**, bool*) () from /usr/lib64/qt5/plugins/org.kde.kdecoration2/kwin5_aurorae.so #18 0x00007f1a8707bf07 in QMetaObject::activate(QObject*, int, int, void**) () from /lib64/libQt5Core.so.5 #19 0x00007f1a87088a68 in QTimer::timerEvent(QTimerEvent*) () from /lib64/libQt5Core.so.5 #20 0x00007f1a8707cef3 in QObject::event(QEvent*) () from /lib64/libQt5Core.so.5 #21 0x00007f1a87d0d7ec in QApplicationPrivate::notify_helper(QObject*, QEvent*) () from /lib64/libQt5Widgets.so.5 #22 0x00007f1a87d12e90 in QApplication::notify(QObject*, QEvent*) () from /lib64/libQt5Widgets.so.5 #23 0x00007f1a8704b67b in QCoreApplication::notifyInternal(QObject*, QEvent*) () from /lib64/libQt5Core.so.5 #24 0x00007f1a870a198d in QTimerInfoList::activateTimers() () from /lib64/libQt5Core.so.5 #25 0x00007f1a870a01a6 in QEventDispatcherUNIX::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /lib64/libQt5Core.so.5 #26 0x00007f1a702ca3dd in QUnixEventDispatcherQPA::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib64/qt5/plugins/platforms/libqxcb.so #27 0x00007f1a87048eba in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () from /lib64/libQt5Core.so.5 #28 0x00007f1a87050a2c in QCoreApplication::exec() () from /lib64/libQt5Core.so.5 #29 0x00007f1a9098ab07 in kdemain () from /lib64/libkdeinit5_kwin_x11.so #30 0x00007f1a85a81700 in __libc_start_main () from /lib64/libc.so.6 #31 0x0000000000400c89 in _start () Reported using DrKonqi
Restarting from the popup is not 100% reliable and, by the way, the popup disappeared once I finished the bug report. I have to log out and start a new session if I want my panel back. I do not know if it is related to the segfault problem or a general feature of the crash popup.
I have just upgraded the system to kernel 4.1.5-200.fc22 qt5 5.5.0-15.fc22 and the problem persists. abrt reports specifically that "kscreenlocker_greet killed by SIGSEGV" from plasma-workspace-5.3.2-2.fc22.x86_64
can you please provide the output of: qdbus org.kde.KWin /KWin supportInformation
Created attachment 94148 [details] qdbus org.kde.KWin /KWin supportInformation Attaching requested informaion.
Thanks. To workaround I recommend changing to the breeze window decoration. Are screens being unplugged while the system is locked?
Thanks, I will try switching to breeze (didn't like it much....). It does sound strange that window decoration scheme may cause a segfault in screenlocker though. The external monitor was not unplugged but turned off after locking the screen. I suppose it is equivalent. I do expect everything to work after turning it on again. The laptop's lid is normally closed, but the power management is set to "do nothing" when the lid is closed, in case it matters.
Re Comment 5: I switched to breeze window decorations and found the following: * I locked and unlocked the screen several times (precise sequence: lock screen - switch off the external monitor - wait a bit - switch on the external monitor - unlock screen); * I got seemingly the same crash once (not the first time) * I did not get the crash pop-up at other times, but the panel disappeared (the main visible effect of the crash besides the reporting pop-up); * the panel appears (and works) if I open the laptop's lid and disappears again if I close it. I suspect this effect is related in some way. If it matters, the panel is set to auto-hide.
(In reply to Oleg Goldshmidt from comment #7) > * I got seemingly the same crash once (not the first time) Conserved the backtrace? Please do so on further crashes (notably w/o the aurorae decoration) to allow for comparism (this may very well be just the Qt5 bug on empty screens and then random things are gonna crash randomly - depending on when they accidentally and implicitly look at something screen related)
I was more interested in verifying repeatability - the first time there was no obvious crash, the second time there was, so I tried to repeat several times. Anyway, here is another backtrace. I didn't try to decypher what happened - I assume you can do it much more efficiently. Thanks. By the way, this time the laptop's lid was open, and the panel did not disappear. Application: Plasma (plasmashell), signal: Segmentation fault Using host libthread_db library "/lib64/libthread_db.so.1". [Current thread is 1 (Thread 0x7f4cdbec6900 (LWP 2750))] Thread 23 (Thread 0x7f4cbc14b700 (LWP 2752)): #0 0x00007f4cd3d352fd in poll () from /lib64/libc.so.6 #1 0x00007f4cda17a182 in _xcb_conn_wait () from /lib64/libxcb.so.1 #2 0x00007f4cda17bc77 in xcb_wait_for_event () from /lib64/libxcb.so.1 #3 0x00007f4cbe2d9999 in QXcbEventReader::run() () from /lib64/libQt5XcbQpa.so.5 #4 0x00007f4cd494154e in QThreadPrivate::start(void*) () from /lib64/libQt5Core.so.5 #5 0x00007f4cd27d3555 in start_thread () from /lib64/libpthread.so.0 #6 0x00007f4cd3d40b9d in clone () from /lib64/libc.so.6 Thread 22 (Thread 0x7f4cb34cf700 (LWP 2754)): #0 0x00007f4cceee4e43 in g_source_iter_next () from /lib64/libglib-2.0.so.0 #1 0x00007f4cceee72fb in g_main_context_prepare () from /lib64/libglib-2.0.so.0 #2 0x00007f4cceee7ceb in g_main_context_iterate.isra () from /lib64/libglib-2.0.so.0 #3 0x00007f4cceee7ecc in g_main_context_iteration () from /lib64/libglib-2.0.so.0 #4 0x00007f4cd4b78dab in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /lib64/libQt5Core.so.5 #5 0x00007f4cd4b1fdaa in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () from /lib64/libQt5Core.so.5 #6 0x00007f4cd493c5a4 in QThread::exec() () from /lib64/libQt5Core.so.5 #7 0x00007f4cd8c10245 in QQmlThreadPrivate::run() () from /lib64/libQt5Qml.so.5 #8 0x00007f4cd494154e in QThreadPrivate::start(void*) () from /lib64/libQt5Core.so.5 #9 0x00007f4cd27d3555 in start_thread () from /lib64/libpthread.so.0 #10 0x00007f4cd3d40b9d in clone () from /lib64/libc.so.6 Thread 21 (Thread 0x7f4caab86700 (LWP 2755)): #0 0x00007f4cd3d352fd in poll () from /lib64/libc.so.6 #1 0x00007f4cceee7dbc in g_main_context_iterate.isra () from /lib64/libglib-2.0.so.0 #2 0x00007f4cceee7ecc in g_main_context_iteration () from /lib64/libglib-2.0.so.0 #3 0x00007f4cd4b78dab in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /lib64/libQt5Core.so.5 #4 0x00007f4cd4b1fdaa in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () from /lib64/libQt5Core.so.5 #5 0x00007f4cd493c5a4 in QThread::exec() () from /lib64/libQt5Core.so.5 #6 0x00007f4cd8c10245 in QQmlThreadPrivate::run() () from /lib64/libQt5Qml.so.5 #7 0x00007f4cd494154e in QThreadPrivate::start(void*) () from /lib64/libQt5Core.so.5 #8 0x00007f4cd27d3555 in start_thread () from /lib64/libpthread.so.0 #9 0x00007f4cd3d40b9d in clone () from /lib64/libc.so.6 Thread 20 (Thread 0x7f4ca9081700 (LWP 2758)): #0 0x00007f4cd4b78100 in timerSourcePrepare(_GSource*, int*) () from /lib64/libQt5Core.so.5 #1 0x00007f4cceee735d in g_main_context_prepare () from /lib64/libglib-2.0.so.0 #2 0x00007f4cceee7ceb in g_main_context_iterate.isra () from /lib64/libglib-2.0.so.0 #3 0x00007f4cceee7ecc in g_main_context_iteration () from /lib64/libglib-2.0.so.0 #4 0x00007f4cd4b78dab in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /lib64/libQt5Core.so.5 #5 0x00007f4cd4b1fdaa in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () from /lib64/libQt5Core.so.5 #6 0x00007f4cd493c5a4 in QThread::exec() () from /lib64/libQt5Core.so.5 #7 0x00007f4cd8c10245 in QQmlThreadPrivate::run() () from /lib64/libQt5Qml.so.5 #8 0x00007f4cd494154e in QThreadPrivate::start(void*) () from /lib64/libQt5Core.so.5 #9 0x00007f4cd27d3555 in start_thread () from /lib64/libpthread.so.0 #10 0x00007f4cd3d40b9d in clone () from /lib64/libc.so.6 Thread 19 (Thread 0x7f4ca3f9f700 (LWP 2759)): #0 0x00007f4ccef2cec9 in g_mutex_lock () from /lib64/libglib-2.0.so.0 #1 0x00007f4cceee7369 in g_main_context_prepare () from /lib64/libglib-2.0.so.0 #2 0x00007f4cceee7ceb in g_main_context_iterate.isra () from /lib64/libglib-2.0.so.0 #3 0x00007f4cceee7ecc in g_main_context_iteration () from /lib64/libglib-2.0.so.0 #4 0x00007f4cd4b78dab in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /lib64/libQt5Core.so.5 #5 0x00007f4cd4b1fdaa in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () from /lib64/libQt5Core.so.5 #6 0x00007f4cd493c5a4 in QThread::exec() () from /lib64/libQt5Core.so.5 #7 0x00007f4cd8c10245 in QQmlThreadPrivate::run() () from /lib64/libQt5Qml.so.5 #8 0x00007f4cd494154e in QThreadPrivate::start(void*) () from /lib64/libQt5Core.so.5 #9 0x00007f4cd27d3555 in start_thread () from /lib64/libpthread.so.0 #10 0x00007f4cd3d40b9d in clone () from /lib64/libc.so.6 Thread 18 (Thread 0x7f4ca2e9e700 (LWP 2760)): #0 0x00007f4cd493a8df in QMutex::unlock() () from /lib64/libQt5Core.so.5 #1 0x00007f4cd4b78615 in postEventSourceCheck(_GSource*) () from /lib64/libQt5Core.so.5 #2 0x00007f4cceee7801 in g_main_context_check () from /lib64/libglib-2.0.so.0 #3 0x00007f4cceee7d60 in g_main_context_iterate.isra () from /lib64/libglib-2.0.so.0 #4 0x00007f4cceee7ecc in g_main_context_iteration () from /lib64/libglib-2.0.so.0 #5 0x00007f4cd4b78dab in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /lib64/libQt5Core.so.5 #6 0x00007f4cd4b1fdaa in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () from /lib64/libQt5Core.so.5 #7 0x00007f4cd493c5a4 in QThread::exec() () from /lib64/libQt5Core.so.5 #8 0x00007f4cd8c10245 in QQmlThreadPrivate::run() () from /lib64/libQt5Qml.so.5 #9 0x00007f4cd494154e in QThreadPrivate::start(void*) () from /lib64/libQt5Core.so.5 #10 0x00007f4cd27d3555 in start_thread () from /lib64/libpthread.so.0 #11 0x00007f4cd3d40b9d in clone () from /lib64/libc.so.6 Thread 17 (Thread 0x7f4ca1d9d700 (LWP 2761)): #0 0x00007f4cd3d4e64f in __libc_enable_asynccancel () from /lib64/libc.so.6 #1 0x00007f4cd3d352f2 in poll () from /lib64/libc.so.6 #2 0x00007f4cceee7dbc in g_main_context_iterate.isra () from /lib64/libglib-2.0.so.0 #3 0x00007f4cceee7ecc in g_main_context_iteration () from /lib64/libglib-2.0.so.0 #4 0x00007f4cd4b78dab in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /lib64/libQt5Core.so.5 #5 0x00007f4cd4b1fdaa in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () from /lib64/libQt5Core.so.5 #6 0x00007f4cd493c5a4 in QThread::exec() () from /lib64/libQt5Core.so.5 #7 0x00007f4cd8c10245 in QQmlThreadPrivate::run() () from /lib64/libQt5Qml.so.5 #8 0x00007f4cd494154e in QThreadPrivate::start(void*) () from /lib64/libQt5Core.so.5 #9 0x00007f4cd27d3555 in start_thread () from /lib64/libpthread.so.0 #10 0x00007f4cd3d40b9d in clone () from /lib64/libc.so.6 Thread 16 (Thread 0x7f4c8ffff700 (LWP 2762)): #0 0x00007f4ccef2cec9 in g_mutex_lock () from /lib64/libglib-2.0.so.0 #1 0x00007f4cceee7369 in g_main_context_prepare () from /lib64/libglib-2.0.so.0 #2 0x00007f4cceee7ceb in g_main_context_iterate.isra () from /lib64/libglib-2.0.so.0 #3 0x00007f4cceee7ecc in g_main_context_iteration () from /lib64/libglib-2.0.so.0 #4 0x00007f4cd4b78dab in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /lib64/libQt5Core.so.5 #5 0x00007f4cd4b1fdaa in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () from /lib64/libQt5Core.so.5 #6 0x00007f4cd493c5a4 in QThread::exec() () from /lib64/libQt5Core.so.5 #7 0x00007f4cd8c10245 in QQmlThreadPrivate::run() () from /lib64/libQt5Qml.so.5 #8 0x00007f4cd494154e in QThreadPrivate::start(void*) () from /lib64/libQt5Core.so.5 #9 0x00007f4cd27d3555 in start_thread () from /lib64/libpthread.so.0 #10 0x00007f4cd3d40b9d in clone () from /lib64/libc.so.6 Thread 15 (Thread 0x7f4c8effe700 (LWP 2763)): #0 0x00007f4cd3d352fd in poll () from /lib64/libc.so.6 #1 0x00007f4cceee7dbc in g_main_context_iterate.isra () from /lib64/libglib-2.0.so.0 #2 0x00007f4cceee7ecc in g_main_context_iteration () from /lib64/libglib-2.0.so.0 #3 0x00007f4cd4b78dab in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /lib64/libQt5Core.so.5 #4 0x00007f4cd4b1fdaa in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () from /lib64/libQt5Core.so.5 #5 0x00007f4cd493c5a4 in QThread::exec() () from /lib64/libQt5Core.so.5 #6 0x00007f4cd8c10245 in QQmlThreadPrivate::run() () from /lib64/libQt5Qml.so.5 #7 0x00007f4cd494154e in QThreadPrivate::start(void*) () from /lib64/libQt5Core.so.5 #8 0x00007f4cd27d3555 in start_thread () from /lib64/libpthread.so.0 #9 0x00007f4cd3d40b9d in clone () from /lib64/libc.so.6 Thread 14 (Thread 0x7f4c8dffd700 (LWP 2764)): #0 0x00007f4cd27d8540 in pthread_cond_wait@@GLIBC_2.3.2 () from /lib64/libpthread.so.0 #1 0x00007f4cdb5e0494 in QTWTF::TCMalloc_PageHeap::scavengerThread() () from /lib64/libQt5Script.so.5 #2 0x00007f4cdb5e04d9 in QTWTF::TCMalloc_PageHeap::runScavengerThread(void*) () from /lib64/libQt5Script.so.5 #3 0x00007f4cd27d3555 in start_thread () from /lib64/libpthread.so.0 #4 0x00007f4cd3d40b9d in clone () from /lib64/libc.so.6 Thread 13 (Thread 0x7f4bfe3c2700 (LWP 2766)): #0 0x00007f4cd3d352fd in poll () from /lib64/libc.so.6 #1 0x00007f4cceee7dbc in g_main_context_iterate.isra () from /lib64/libglib-2.0.so.0 #2 0x00007f4cceee7ecc in g_main_context_iteration () from /lib64/libglib-2.0.so.0 #3 0x00007f4cd4b78dab in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /lib64/libQt5Core.so.5 #4 0x00007f4cd4b1fdaa in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () from /lib64/libQt5Core.so.5 #5 0x00007f4cd493c5a4 in QThread::exec() () from /lib64/libQt5Core.so.5 #6 0x00007f4cd9283616 in QQuickPixmapReader::run() () from /lib64/libQt5Quick.so.5 #7 0x00007f4cd494154e in QThreadPrivate::start(void*) () from /lib64/libQt5Core.so.5 #8 0x00007f4cd27d3555 in start_thread () from /lib64/libpthread.so.0 #9 0x00007f4cd3d40b9d in clone () from /lib64/libc.so.6 Thread 12 (Thread 0x7f4bea56c700 (LWP 2769)): #0 0x00007f4ccef2cec9 in g_mutex_lock () from /lib64/libglib-2.0.so.0 #1 0x00007f4cceee6ea4 in g_main_context_release () from /lib64/libglib-2.0.so.0 #2 0x00007f4cceee7d76 in g_main_context_iterate.isra () from /lib64/libglib-2.0.so.0 #3 0x00007f4cceee7ecc in g_main_context_iteration () from /lib64/libglib-2.0.so.0 #4 0x00007f4cd4b78dab in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /lib64/libQt5Core.so.5 #5 0x00007f4cd4b1fdaa in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () from /lib64/libQt5Core.so.5 #6 0x00007f4cd493c5a4 in QThread::exec() () from /lib64/libQt5Core.so.5 #7 0x00007f4cd8c10245 in QQmlThreadPrivate::run() () from /lib64/libQt5Qml.so.5 #8 0x00007f4cd494154e in QThreadPrivate::start(void*) () from /lib64/libQt5Core.so.5 #9 0x00007f4cd27d3555 in start_thread () from /lib64/libpthread.so.0 #10 0x00007f4cd3d40b9d in clone () from /lib64/libc.so.6 Thread 11 (Thread 0x7f4be94eb700 (LWP 2770)): #0 0x00007f4cd3d30fad in read () from /lib64/libc.so.6 #1 0x00007f4ccef2bb00 in g_wakeup_acknowledge () from /lib64/libglib-2.0.so.0 #2 0x00007f4cceee78b4 in g_main_context_check () from /lib64/libglib-2.0.so.0 #3 0x00007f4cceee7d60 in g_main_context_iterate.isra () from /lib64/libglib-2.0.so.0 #4 0x00007f4cceee7ecc in g_main_context_iteration () from /lib64/libglib-2.0.so.0 #5 0x00007f4cd4b78dab in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /lib64/libQt5Core.so.5 #6 0x00007f4cd4b1fdaa in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () from /lib64/libQt5Core.so.5 #7 0x00007f4cd493c5a4 in QThread::exec() () from /lib64/libQt5Core.so.5 #8 0x00007f4cd8c10245 in QQmlThreadPrivate::run() () from /lib64/libQt5Qml.so.5 #9 0x00007f4cd494154e in QThreadPrivate::start(void*) () from /lib64/libQt5Core.so.5 #10 0x00007f4cd27d3555 in start_thread () from /lib64/libpthread.so.0 #11 0x00007f4cd3d40b9d in clone () from /lib64/libc.so.6 Thread 10 (Thread 0x7f4be0dec700 (LWP 2771)): #0 0x00007f4ccef2cec9 in g_mutex_lock () from /lib64/libglib-2.0.so.0 #1 0x00007f4cceee7369 in g_main_context_prepare () from /lib64/libglib-2.0.so.0 #2 0x00007f4cceee7ceb in g_main_context_iterate.isra () from /lib64/libglib-2.0.so.0 #3 0x00007f4cceee7ecc in g_main_context_iteration () from /lib64/libglib-2.0.so.0 #4 0x00007f4cd4b78dab in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /lib64/libQt5Core.so.5 #5 0x00007f4cd4b1fdaa in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () from /lib64/libQt5Core.so.5 #6 0x00007f4cd493c5a4 in QThread::exec() () from /lib64/libQt5Core.so.5 #7 0x00007f4be2a3b397 in KCupsConnection::run() () from /lib64/libkcupslib.so #8 0x00007f4cd494154e in QThreadPrivate::start(void*) () from /lib64/libQt5Core.so.5 #9 0x00007f4cd27d3555 in start_thread () from /lib64/libpthread.so.0 #10 0x00007f4cd3d40b9d in clone () from /lib64/libc.so.6 Thread 9 (Thread 0x7f4bd7f0f700 (LWP 2772)): #0 0x00007f4ccef2cec9 in g_mutex_lock () from /lib64/libglib-2.0.so.0 #1 0x00007f4cceee7eb8 in g_main_context_iteration () from /lib64/libglib-2.0.so.0 #2 0x00007f4cd4b78dab in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /lib64/libQt5Core.so.5 #3 0x00007f4cd4b1fdaa in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () from /lib64/libQt5Core.so.5 #4 0x00007f4cd493c5a4 in QThread::exec() () from /lib64/libQt5Core.so.5 #5 0x00007f4cd8c10245 in QQmlThreadPrivate::run() () from /lib64/libQt5Qml.so.5 #6 0x00007f4cd494154e in QThreadPrivate::start(void*) () from /lib64/libQt5Core.so.5 #7 0x00007f4cd27d3555 in start_thread () from /lib64/libpthread.so.0 #8 0x00007f4cd3d40b9d in clone () from /lib64/libc.so.6 Thread 8 (Thread 0x7f4bd6e0c700 (LWP 2773)): #0 0x00007f4ccef2cec9 in g_mutex_lock () from /lib64/libglib-2.0.so.0 #1 0x00007f4cceee780c in g_main_context_check () from /lib64/libglib-2.0.so.0 #2 0x00007f4cceee7d60 in g_main_context_iterate.isra () from /lib64/libglib-2.0.so.0 #3 0x00007f4cceee7ecc in g_main_context_iteration () from /lib64/libglib-2.0.so.0 #4 0x00007f4cd4b78dab in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /lib64/libQt5Core.so.5 #5 0x00007f4cd4b1fdaa in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () from /lib64/libQt5Core.so.5 #6 0x00007f4cd493c5a4 in QThread::exec() () from /lib64/libQt5Core.so.5 #7 0x00007f4cd8c10245 in QQmlThreadPrivate::run() () from /lib64/libQt5Qml.so.5 #8 0x00007f4cd494154e in QThreadPrivate::start(void*) () from /lib64/libQt5Core.so.5 #9 0x00007f4cd27d3555 in start_thread () from /lib64/libpthread.so.0 #10 0x00007f4cd3d40b9d in clone () from /lib64/libc.so.6 Thread 7 (Thread 0x7f4bd5ada700 (LWP 2774)): #0 0x00007f4ccef2cee4 in g_mutex_unlock () from /lib64/libglib-2.0.so.0 #1 0x00007f4cceee7639 in g_main_context_query () from /lib64/libglib-2.0.so.0 #2 0x00007f4cceee7d37 in g_main_context_iterate.isra () from /lib64/libglib-2.0.so.0 #3 0x00007f4cceee7ecc in g_main_context_iteration () from /lib64/libglib-2.0.so.0 #4 0x00007f4cd4b78dab in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /lib64/libQt5Core.so.5 #5 0x00007f4cd4b1fdaa in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () from /lib64/libQt5Core.so.5 #6 0x00007f4cd493c5a4 in QThread::exec() () from /lib64/libQt5Core.so.5 #7 0x00007f4cd8c10245 in QQmlThreadPrivate::run() () from /lib64/libQt5Qml.so.5 #8 0x00007f4cd494154e in QThreadPrivate::start(void*) () from /lib64/libQt5Core.so.5 #9 0x00007f4cd27d3555 in start_thread () from /lib64/libpthread.so.0 #10 0x00007f4cd3d40b9d in clone () from /lib64/libc.so.6 Thread 6 (Thread 0x7f4bd49f9700 (LWP 2775)): #0 0x00007f4cceee7250 in g_main_context_prepare () from /lib64/libglib-2.0.so.0 #1 0x00007f4cceee7ceb in g_main_context_iterate.isra () from /lib64/libglib-2.0.so.0 #2 0x00007f4cceee7ecc in g_main_context_iteration () from /lib64/libglib-2.0.so.0 #3 0x00007f4cd4b78dab in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /lib64/libQt5Core.so.5 #4 0x00007f4cd4b1fdaa in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () from /lib64/libQt5Core.so.5 #5 0x00007f4cd493c5a4 in QThread::exec() () from /lib64/libQt5Core.so.5 #6 0x00007f4cd8c10245 in QQmlThreadPrivate::run() () from /lib64/libQt5Qml.so.5 #7 0x00007f4cd494154e in QThreadPrivate::start(void*) () from /lib64/libQt5Core.so.5 #8 0x00007f4cd27d3555 in start_thread () from /lib64/libpthread.so.0 #9 0x00007f4cd3d40b9d in clone () from /lib64/libc.so.6 Thread 5 (Thread 0x7f4c8d7fc700 (LWP 3069)): #0 0x00007f4cd3d352fd in poll () from /lib64/libc.so.6 #1 0x00007f4cceee7dbc in g_main_context_iterate.isra () from /lib64/libglib-2.0.so.0 #2 0x00007f4cceee7ecc in g_main_context_iteration () from /lib64/libglib-2.0.so.0 #3 0x00007f4cd4b78dab in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /lib64/libQt5Core.so.5 #4 0x00007f4cd4b1fdaa in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () from /lib64/libQt5Core.so.5 #5 0x00007f4cd493c5a4 in QThread::exec() () from /lib64/libQt5Core.so.5 #6 0x00007f4cd8c10245 in QQmlThreadPrivate::run() () from /lib64/libQt5Qml.so.5 #7 0x00007f4cd494154e in QThreadPrivate::start(void*) () from /lib64/libQt5Core.so.5 #8 0x00007f4cd27d3555 in start_thread () from /lib64/libpthread.so.0 #9 0x00007f4cd3d40b9d in clone () from /lib64/libc.so.6 Thread 4 (Thread 0x7f4bf67ff700 (LWP 3219)): #0 0x00007f4ccef2cee4 in g_mutex_unlock () from /lib64/libglib-2.0.so.0 #1 0x00007f4cceee77f9 in g_main_context_check () from /lib64/libglib-2.0.so.0 #2 0x00007f4cceee7d60 in g_main_context_iterate.isra () from /lib64/libglib-2.0.so.0 #3 0x00007f4cceee7ecc in g_main_context_iteration () from /lib64/libglib-2.0.so.0 #4 0x00007f4cd4b78dab in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /lib64/libQt5Core.so.5 #5 0x00007f4cd4b1fdaa in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () from /lib64/libQt5Core.so.5 #6 0x00007f4cd493c5a4 in QThread::exec() () from /lib64/libQt5Core.so.5 #7 0x00007f4cd8c10245 in QQmlThreadPrivate::run() () from /lib64/libQt5Qml.so.5 #8 0x00007f4cd494154e in QThreadPrivate::start(void*) () from /lib64/libQt5Core.so.5 #9 0x00007f4cd27d3555 in start_thread () from /lib64/libpthread.so.0 #10 0x00007f4cd3d40b9d in clone () from /lib64/libc.so.6 Thread 3 (Thread 0x7f4bfdbc1700 (LWP 3221)): #0 0x00007f4ccef2cee4 in g_mutex_unlock () from /lib64/libglib-2.0.so.0 #1 0x00007f4cceee7350 in g_main_context_prepare () from /lib64/libglib-2.0.so.0 #2 0x00007f4cceee7ceb in g_main_context_iterate.isra () from /lib64/libglib-2.0.so.0 #3 0x00007f4cceee7ecc in g_main_context_iteration () from /lib64/libglib-2.0.so.0 #4 0x00007f4cd4b78dab in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /lib64/libQt5Core.so.5 #5 0x00007f4cd4b1fdaa in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () from /lib64/libQt5Core.so.5 #6 0x00007f4cd493c5a4 in QThread::exec() () from /lib64/libQt5Core.so.5 #7 0x00007f4cd8c10245 in QQmlThreadPrivate::run() () from /lib64/libQt5Qml.so.5 #8 0x00007f4cd494154e in QThreadPrivate::start(void*) () from /lib64/libQt5Core.so.5 #9 0x00007f4cd27d3555 in start_thread () from /lib64/libpthread.so.0 #10 0x00007f4cd3d40b9d in clone () from /lib64/libc.so.6 Thread 2 (Thread 0x7f4bbf425700 (LWP 4083)): #0 0x00007f4cd4b76d97 in QTimerInfoList::timerWait(timespec&) () from /lib64/libQt5Core.so.5 #1 0x00007f4cd4b7818e in timerSourcePrepare(_GSource*, int*) () from /lib64/libQt5Core.so.5 #2 0x00007f4cceee735d in g_main_context_prepare () from /lib64/libglib-2.0.so.0 #3 0x00007f4cceee7ceb in g_main_context_iterate.isra () from /lib64/libglib-2.0.so.0 #4 0x00007f4cceee7ecc in g_main_context_iteration () from /lib64/libglib-2.0.so.0 #5 0x00007f4cd4b78dab in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /lib64/libQt5Core.so.5 #6 0x00007f4cd4b1fdaa in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () from /lib64/libQt5Core.so.5 #7 0x00007f4cd493c5a4 in QThread::exec() () from /lib64/libQt5Core.so.5 #8 0x00007f4cd8c10245 in QQmlThreadPrivate::run() () from /lib64/libQt5Qml.so.5 #9 0x00007f4cd494154e in QThreadPrivate::start(void*) () from /lib64/libQt5Core.so.5 #10 0x00007f4cd27d3555 in start_thread () from /lib64/libpthread.so.0 #11 0x00007f4cd3d40b9d in clone () from /lib64/libc.so.6 Thread 1 (Thread 0x7f4cdbec6900 (LWP 2750)): [KCrash Handler] #5 0x00007f4cd9ee1320 in Plasma::Applet::actions() const () from /lib64/libKF5Plasma.so.5 #6 0x00000000004520f9 in ShellCorona::addOutput(QSharedPointer<KScreen::Output> const&) () #7 0x000000000045227f in ShellCorona::outputEnabledChanged() () #8 0x00007f4cd4b50fe7 in QMetaObject::activate(QObject*, int, int, void**) () from /lib64/libQt5Core.so.5 #9 0x00007f4cdad34977 in KScreen::Output::apply(QSharedPointer<KScreen::Output> const&) () from /lib64/libKF5Screen.so.6 #10 0x00007f4cdad1fc8e in KScreen::Config::apply(QSharedPointer<KScreen::Config> const&) () from /lib64/libKF5Screen.so.6 #11 0x00007f4cdad26fb9 in KScreen::ConfigMonitor::Private::updateConfigs(QSharedPointer<KScreen::Config> const&) () from /lib64/libKF5Screen.so.6 #12 0x00007f4cdad29309 in KScreen::ConfigMonitor::Private::edidReady(QDBusPendingCallWatcher*) () from /lib64/libKF5Screen.so.6 #13 0x00007f4cd4b50fe7 in QMetaObject::activate(QObject*, int, int, void**) () from /lib64/libQt5Core.so.5 #14 0x00007f4cd591c74f in QDBusPendingCallWatcher::finished(QDBusPendingCallWatcher*) () from /lib64/libQt5DBus.so.5 #15 0x00007f4cd591de25 in QDBusPendingCallWatcher::qt_static_metacall(QObject*, QMetaObject::Call, int, void**) () from /lib64/libQt5DBus.so.5 #16 0x00007f4cd4b52021 in QObject::event(QEvent*) () from /lib64/libQt5Core.so.5 #17 0x00007f4cd60d84ac in QApplicationPrivate::notify_helper(QObject*, QEvent*) () from /lib64/libQt5Widgets.so.5 #18 0x00007f4cd60dd976 in QApplication::notify(QObject*, QEvent*) () from /lib64/libQt5Widgets.so.5 #19 0x00007f4cd4b2261b in QCoreApplication::notifyInternal(QObject*, QEvent*) () from /lib64/libQt5Core.so.5 #20 0x00007f4cd4b24a16 in QCoreApplicationPrivate::sendPostedEvents(QObject*, int, QThreadData*) () from /lib64/libQt5Core.so.5 #21 0x00007f4cd4b78983 in postEventSourceDispatch(_GSource*, int (*)(void*), void*) () from /lib64/libQt5Core.so.5 #22 0x00007f4cceee7a8a in g_main_context_dispatch () from /lib64/libglib-2.0.so.0 #23 0x00007f4cceee7e20 in g_main_context_iterate.isra () from /lib64/libglib-2.0.so.0 #24 0x00007f4cceee7ecc in g_main_context_iteration () from /lib64/libglib-2.0.so.0 #25 0x00007f4cd4b78d8f in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /lib64/libQt5Core.so.5 #26 0x00007f4cd4b1fdaa in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () from /lib64/libQt5Core.so.5 #27 0x00007f4cd4b27e6c in QCoreApplication::exec() () from /lib64/libQt5Core.so.5 #28 0x000000000042ef16 in main ()
That's actually a crash of plasmashell (desktop process) not kwin_x11 (window manager process) However, while I'm not experienced in plasmashell backtraces, this: > #5 0x00007f4cd9ee1320 in Plasma::Applet::actions() const () from /lib64/libKF5Plasma.so.5 > #6 0x00000000004520f9 in ShellCorona::addOutput(QSharedPointer<KScreen::Output> const&) () > #7 0x000000000045227f in ShellCorona::outputEnabledChanged() () > #8 0x00007f4cd4b50fe7 in QMetaObject::activate(QObject*, int, int, void**) () from /lib64/libQt5Core.so.5 > #9 0x00007f4cdad34977 in KScreen::Output::apply(QSharedPointer<KScreen::Output> const&) () from /lib64/libKF5Screen.so.6 Looks a hell lot like the QScreen nullprt bug. Bottom line: this is *very* likely bug #351007 and both are "just" bug #341497 and that is actually https://bugreports.qt.io/browse/QTBUG-32973
(In reply to Thomas Lübking from comment #10) > That's actually a crash of plasmashell (desktop process) not kwin_x11 > (window manager process) I noticed, but I cannot decide how related or unrelated it is. > Bottom line: > this is *very* likely bug #351007 and both are "just" bug #341497 and that > is actually https://bugreports.qt.io/browse/QTBUG-32973 I'll obviously defer to you, but allow me to make the following 2 comments: * https://bugs.kde.org/show_bug.cgi?id=341497#c6 says "it should be fixed in QT 5.5" and I am on qt5 5.5 now (cf. Comment 2 above). I'd rather check if it is not similar to https://bugs.kde.org/show_bug.cgi?id=341497#c21 * QTBUG-32973 is about applications crashing and windows disappearing. In my case all the windows remain intact. Thanks a lot.
(In reply to Oleg Goldshmidt from comment #11) > * https://bugs.kde.org/show_bug.cgi?id=341497#c6 says "it should be fixed in > QT 5.5" and I am on qt5 5.5 now (cf. Comment 2 above). I'd rather check if > it is not similar to https://bugs.kde.org/show_bug.cgi?id=341497#c21 "Should" - but I haven't seen a patch that supports that idea and unfortunately we get QScreen 0x0 bugs on Qt5.5. So atm. I tend to say "isn't" (see end of post) The crash occurs in various occasions with one common part: Qt resolves a QScreen from the list wich is 0x0 and then does "something" with that screen. Either there needs to be a dummy screen (so the list never gets empty) or the "no screen" condition caught. > * QTBUG-32973 is about applications crashing and windows disappearing. In my > case all the windows remain intact. The actual bug is https://bugreports.qt.io/browse/QTBUG-38129 but it's been closed as duplicate of https://bugreports.qt.io/browse/QTBUG-32973 Looking at it, QTBUG-32973 was closed by https://codereview.qt-project.org/#/c/87885/ which fixes *one* particular issue on accessing the 0x0 screen (windows being moved to a non existing screen) If that's supposed to be the fix, the bug is there just as much.
There is something else that is suspicious regarding the suggested connection between various bugs. In my case, both the external monitor and the laptop's display have a picture before and after unlocking. The laptop's display is *not* turned off when the screen is locked. This does not look consistent with an empty monitor list, with a 0x0 pointer, etc. I realize that the video signal and cursor and keyboard may be handled by a different layer (X11?) while KWin and/or QT may have a bug. But then it seems to be a logical bug, in the sense that X11 does the right thing and QT does not (and does not ask a lower layer what resources are present? not sure how it is supposed to work...).
The presense of physical screens/displays is completely irrelevant. This happens for "most™" randr events, eg. also when changing your resolution. Please install debug enabled packages, wait for a crash - I bet your right arm there's a QScreen(0x0) in the backtrace.
(In reply to Thomas Lübking from comment #14) > The presense of physical screens/displays is completely irrelevant. This > happens for "most™" randr events, eg. also when changing your resolution. If that is the case, I certainly hope it will be fixed very soon. ;-) > Please install debug enabled packages, wait for a crash While I am willing to help, this is my main personal laptop, so I am reluctant to make sweeping changes. I am on Fedora 22, there usually are additional debuginfo packages. Out of the multitude qt/kde rpms, can you suggest a subset that I can install debuginfo for and then remove? E.g., dnf debuginfo-install kwin attempts to pull in 131 packages (no, I didn't run it), but nothing related to, say, plasma, etc., so I suspect one would need many more. If I manage to reproduce it on less valuable machine, I'll add the backtrace, but this may take time. Do let me know how useful this will be. > I bet your right arm ... and my backups, eh? > there's a QScreen(0x0) in the backtrace. Thanks.
For the original bakctrace, you'll require the QtQuick & QtGui debug packages (no idea how fedora names them, sorry) I'm however pretty convinced to know the result (I wouldn't risk your arm otherwise ;-)
Thomas Lübking <thomas.luebking@gmail.com> writes: > --- Comment #16 from Thomas Lübking <thomas.luebking@gmail.com> --- > > I'm however pretty convinced to know the result (I wouldn't risk your > arm otherwise ;-) I just took it as conclusive proof of KDE's ties with Military Intelligence ("we bet your lives", etc.) Seriously though, I hope it gets fixed soon - it looks pretty serious and annoying. If it is a QT bug, can I assume you guys communicate or would you suggest to open another ticket with QT?
It's actually reported as still open (sorry, took me a while to seek through this messy agile board thing ;-) https://bugreports.qt.io/browse/QTBUG-47385
In addition we have https://bugreports.qt.io/browse/QTBUG-42985 if we want to have that fixed, we should report any more info to that upstream there, its nothing we can work around in our code. There the other issue is linked, too, that I reported to Qt.
*** This bug has been marked as a duplicate of bug 341497 ***