Bug 419759

Summary: Set multi-monitor mode to "Unify outputs", disconnect external monitor, turn it off and reconnect it: kwin_wayland crashes.
Product: [Plasma] kwin Reporter: Patrick Silva <bugseforuns>
Component: wayland-genericAssignee: KWin default assignee <kwin-bugs-null>
Status: RESOLVED WORKSFORME    
Severity: crash CC: herzenschein, kode54
Priority: NOR    
Version First Reported In: git master   
Target Milestone: ---   
Platform: Neon   
OS: Linux   
Latest Commit: Version Fixed/Implemented In:
Sentry Crash Report:

Description Patrick Silva 2020-04-06 19:56:16 UTC 
STEPS TO REPRODUCE
1. start Wayland session
2. connect an external monitor to hdmi port and turn it on
3. set multi-monitor mode to "Unify outputs"
4. disconnect the hdmi cable from hdmi port
5. turn off the external monitor by pressing its physical on/off button
6. reconnect the external monitor to hdmi port

OBSERVED RESULT
kwin_wayland crashes

EXPECTED RESULT
no crash

SOFTWARE/OS VERSIONS
Operating System: KDE neon Unstable Edition
KDE Plasma Version: 5.18.80
KDE Frameworks Version: 5.69.0
Qt Version: 5.14.1
Comment 1 Patrick Silva 2020-04-06 19:56:46 UTC 
Thread 11 (Thread 1092.1147):
#0  0x00007f60c3d8b9f3 in futex_wait_cancelable (private=<optimized out>, expected=0, futex_word=0x7f60c1953fb8 <QTWTF::pageheap_memory+57592>)
    at ../sysdeps/unix/sysv/linux/futex-internal.h:88
#1  __pthread_cond_wait_common (abstime=0x0, mutex=0x7f60c1953f68 <QTWTF::pageheap_memory+57512>, cond=0x7f60c1953f90 <QTWTF::pageheap_memory+57552>)
    at pthread_cond_wait.c:502
#2  __pthread_cond_wait (cond=cond@entry=0x7f60c1953f90 <QTWTF::pageheap_memory+57552>, mutex=mutex@entry=0x7f60c1953f68 <QTWTF::pageheap_memory+57512>)
    at pthread_cond_wait.c:655
#3  0x00007f60c165e944 in QTWTF::TCMalloc_PageHeap::scavengerThread (this=0x7f60c1945ec0 <QTWTF::pageheap_memory>)
    at ../3rdparty/javascriptcore/JavaScriptCore/wtf/FastMalloc.cpp:2359
#4  0x00007f60c165e989 in QTWTF::TCMalloc_PageHeap::runScavengerThread (context=<optimized out>) at ../3rdparty/javascriptcore/JavaScriptCore/wtf/FastMalloc.cpp:1464
#5  0x00007f60c3d856db in start_thread (arg=0x7f60767fc700) at pthread_create.c:463
#6  0x00007f60c1d9588f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 10 (Thread 1092.1146):
#0  syscall () at ../sysdeps/unix/sysv/linux/x86_64/syscall.S:38
#1  0x00007f60c26cad44 in QtLinuxFutex::_q_futex (val3=0, addr2=0x0, val2=0, val=<optimized out>, op=0, addr=<optimized out>) at thread/qfutex_p.h:116
#2  QtLinuxFutex::futexWait<QBasicAtomicInteger<unsigned int> > (expectedValue=<optimized out>, futex=...) at thread/qfutex_p.h:135
#3  futexSemaphoreTryAcquire_loop<false> (timeout=-1, nn=8589934593, curValue=<optimized out>, u=...) at thread/qsemaphore.cpp:219
#4  futexSemaphoreTryAcquire<false> (timeout=-1, n=n@entry=1, u=...) at thread/qsemaphore.cpp:262
#5  QSemaphore::acquire (this=this@entry=0x555d001b6050, n=n@entry=1) at thread/qsemaphore.cpp:326
#6  0x00007f60abf22d7a in QtVirtualKeyboard::HunspellWorker::run (this=0x555d001b6030) at hunspellworker.cpp:744
#7  0x00007f60c26c87ec in QThreadPrivate::start (arg=0x555d001b6030) at thread/qthread_unix.cpp:342
#8  0x00007f60c3d856db in start_thread (arg=0x7f6076ffd700) at pthread_create.c:463
#9  0x00007f60c1d9588f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 9 (Thread 1092.1144):
#0  0x00007f60c3d8b9f3 in futex_wait_cancelable (private=<optimized out>, expected=0, futex_word=0x555cffefcb20) at ../sysdeps/unix/sysv/linux/futex-internal.h:88
#1  __pthread_cond_wait_common (abstime=0x0, mutex=0x555cffefcad0, cond=0x555cffefcaf8) at pthread_cond_wait.c:502
#2  __pthread_cond_wait (cond=cond@entry=0x555cffefcaf8, mutex=mutex@entry=0x555cffefcad0) at pthread_cond_wait.c:655
#3  0x00007f60c26ced9b in QWaitConditionPrivate::wait (deadline=..., this=0x555cffefcad0) at thread/qwaitcondition_unix.cpp:146
#4  QWaitCondition::wait (this=<optimized out>, mutex=0x555cffefc938, deadline=...) at thread/qwaitcondition_unix.cpp:225
#5  0x00007f60c26cef19 in QWaitCondition::wait (this=this@entry=0x555cffefc940, mutex=mutex@entry=0x555cffefc938, time=time@entry=18446744073709551615)
    at thread/qwaitcondition_unix.cpp:208
#6  0x00007f607d6de8eb in FileInfoThread::run (this=0x555cffefc928) at fileinfothread.cpp:231
#7  0x00007f60c26c87ec in QThreadPrivate::start (arg=0x555cffefc928) at thread/qthread_unix.cpp:342
#8  0x00007f60c3d856db in start_thread (arg=0x7f6077fff700) at pthread_create.c:463
#9  0x00007f60c1d9588f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 8 (Thread 1092.1143):
#0  syscall () at ../sysdeps/unix/sysv/linux/x86_64/syscall.S:38
#1  0x00007f60c26cad44 in QtLinuxFutex::_q_futex (val3=0, addr2=0x0, val2=0, val=<optimized out>, op=0, addr=<optimized out>) at thread/qfutex_p.h:116
#2  QtLinuxFutex::futexWait<QBasicAtomicInteger<unsigned int> > (expectedValue=<optimized out>, futex=...) at thread/qfutex_p.h:135
#3  futexSemaphoreTryAcquire_loop<false> (timeout=-1, nn=8589934593, curValue=<optimized out>, u=...) at thread/qsemaphore.cpp:219
#4  futexSemaphoreTryAcquire<false> (timeout=-1, n=n@entry=1, u=...) at thread/qsemaphore.cpp:262
#5  QSemaphore::acquire (this=this@entry=0x555d005e9fc0, n=n@entry=1) at thread/qsemaphore.cpp:326
#6  0x00007f60abf22d7a in QtVirtualKeyboard::HunspellWorker::run (this=0x555d005e9fa0) at hunspellworker.cpp:744
#7  0x00007f60c26c87ec in QThreadPrivate::start (arg=0x555d005e9fa0) at thread/qthread_unix.cpp:342
#8  0x00007f60c3d856db in start_thread (arg=0x7f607cab6700) at pthread_create.c:463
#9  0x00007f60c1d9588f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 7 (Thread 1092.1142):
#0  0x00007f60c1d88bf9 in __GI___poll (fds=0x7f60800029e0, nfds=1, timeout=-1) at ../sysdeps/unix/sysv/linux/poll.c:29
#1  0x00007f60b916a5c9 in ?? () from target:/usr/lib/x86_64-linux-gnu/libglib-2.0.so.0
#2  0x00007f60b916a6dc in g_main_context_iteration () from target:/usr/lib/x86_64-linux-gnu/libglib-2.0.so.0
#3  0x00007f60c29170bc in QEventDispatcherGlib::processEvents (this=0x7f6080000b20, flags=...) at kernel/qeventdispatcher_glib.cpp:423
#4  0x00007f60c28b663a in QEventLoop::exec (this=this@entry=0x7f6088f8bd80, flags=..., flags@entry=...) at kernel/qeventloop.cpp:225
#5  0x00007f60c26c7317 in QThread::exec (this=this@entry=0x555d0005b510) at thread/qthread.cpp:536
#6  0x00007f60bdabc605 in QQmlThreadPrivate::run (this=0x555d0005b510) at qml/ftw/qqmlthread.cpp:155
#7  0x00007f60c26c87ec in QThreadPrivate::start (arg=0x555d0005b510) at thread/qthread_unix.cpp:342
#8  0x00007f60c3d856db in start_thread (arg=0x7f6088f8c700) at pthread_create.c:463
#9  0x00007f60c1d9588f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 6 (Thread 1092.1136):
#0  0x00007f60c1d88bf9 in __GI___poll (fds=0x7f6084002de0, nfds=1, timeout=-1) at ../sysdeps/unix/sysv/linux/poll.c:29
#1  0x00007f60b916a5c9 in ?? () from target:/usr/lib/x86_64-linux-gnu/libglib-2.0.so.0
#2  0x00007f60b916a6dc in g_main_context_iteration () from target:/usr/lib/x86_64-linux-gnu/libglib-2.0.so.0
#3  0x00007f60c29170bc in QEventDispatcherGlib::processEvents (this=0x7f6084000b20, flags=...) at kernel/qeventdispatcher_glib.cpp:423
#4  0x00007f60c28b663a in QEventLoop::exec (this=this@entry=0x7f6092f39d80, flags=..., flags@entry=...) at kernel/qeventloop.cpp:225
#5  0x00007f60c26c7317 in QThread::exec (this=this@entry=0x555cffab2510) at thread/qthread.cpp:536
#6  0x00007f60bdabc605 in QQmlThreadPrivate::run (this=0x555cffab2510) at qml/ftw/qqmlthread.cpp:155
#7  0x00007f60c26c87ec in QThreadPrivate::start (arg=0x555cffab2510) at thread/qthread_unix.cpp:342
#8  0x00007f60c3d856db in start_thread (arg=0x7f6092f3a700) at pthread_create.c:463
#9  0x00007f60c1d9588f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 5 (Thread 1092.1113):
#0  0x00007f60c3d8b9f3 in futex_wait_cancelable (private=<optimized out>, expected=0, futex_word=0x555cffa81d48) at ../sysdeps/unix/sysv/linux/futex-internal.h:88
#1  __pthread_cond_wait_common (abstime=0x0, mutex=0x555cffa81cf8, cond=0x555cffa81d20) at pthread_cond_wait.c:502
#2  __pthread_cond_wait (cond=0x555cffa81d20, mutex=0x555cffa81cf8) at pthread_cond_wait.c:655
#3  0x00007f609ae2fecb in ?? () from target:/usr/lib/x86_64-linux-gnu/dri/i965_dri.so
#4  0x00007f609ae2fac7 in ?? () from target:/usr/lib/x86_64-linux-gnu/dri/i965_dri.so
#5  0x00007f60c3d856db in start_thread (arg=0x7f6099792700) at pthread_create.c:463
#6  0x00007f60c1d9588f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 4 (Thread 1092.1112):
#0  0x00007f60c1d88bf9 in __GI___poll (fds=0x7f60a00029e0, nfds=2, timeout=-1) at ../sysdeps/unix/sysv/linux/poll.c:29
#1  0x00007f60b916a5c9 in ?? () from target:/usr/lib/x86_64-linux-gnu/libglib-2.0.so.0
#2  0x00007f60b916a6dc in g_main_context_iteration () from target:/usr/lib/x86_64-linux-gnu/libglib-2.0.so.0
#3  0x00007f60c29170bc in QEventDispatcherGlib::processEvents (this=0x7f60a0000b20, flags=...) at kernel/qeventdispatcher_glib.cpp:423
#4  0x00007f60c28b663a in QEventLoop::exec (this=this@entry=0x7f60a9d96da0, flags=..., flags@entry=...) at kernel/qeventloop.cpp:225
#5  0x00007f60c26c7317 in QThread::exec (this=<optimized out>) at thread/qthread.cpp:536
#6  0x00007f60c26c87ec in QThreadPrivate::start (arg=0x555cff9e86b0) at thread/qthread_unix.cpp:342
#7  0x00007f60c3d856db in start_thread (arg=0x7f60a9d97700) at pthread_create.c:463
#8  0x00007f60c1d9588f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 3 (Thread 1092.1111):
#0  0x00007f60c1d88bf9 in __GI___poll (fds=0x7f609c002de0, nfds=2, timeout=-1) at ../sysdeps/unix/sysv/linux/poll.c:29
#1  0x00007f60b916a5c9 in ?? () from target:/usr/lib/x86_64-linux-gnu/libglib-2.0.so.0
#2  0x00007f60b916a6dc in g_main_context_iteration () from target:/usr/lib/x86_64-linux-gnu/libglib-2.0.so.0
#3  0x00007f60c29170bc in QEventDispatcherGlib::processEvents (this=0x7f609c000b20, flags=...) at kernel/qeventdispatcher_glib.cpp:423
#4  0x00007f60c28b663a in QEventLoop::exec (this=this@entry=0x7f60aa597da0, flags=..., flags@entry=...) at kernel/qeventloop.cpp:225
#5  0x00007f60c26c7317 in QThread::exec (this=<optimized out>) at thread/qthread.cpp:536
#6  0x00007f60c26c87ec in QThreadPrivate::start (arg=0x555cff9e76e0) at thread/qthread_unix.cpp:342
#7  0x00007f60c3d856db in start_thread (arg=0x7f60aa598700) at pthread_create.c:463
#8  0x00007f60c1d9588f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 2 (Thread 1092.1110):
#0  0x00007f60c1d88bf9 in __GI___poll (fds=0x7f60a4017880, nfds=5, timeout=-1) at ../sysdeps/unix/sysv/linux/poll.c:29
#1  0x00007f60b916a5c9 in ?? () from target:/usr/lib/x86_64-linux-gnu/libglib-2.0.so.0
#2  0x00007f60b916a6dc in g_main_context_iteration () from target:/usr/lib/x86_64-linux-gnu/libglib-2.0.so.0
#3  0x00007f60c29170bc in QEventDispatcherGlib::processEvents (this=0x7f60a4000b20, flags=...) at kernel/qeventdispatcher_glib.cpp:423
#4  0x00007f60c28b663a in QEventLoop::exec (this=this@entry=0x7f60ab3fed70, flags=..., flags@entry=...) at kernel/qeventloop.cpp:225
#5  0x00007f60c26c7317 in QThread::exec (this=this@entry=0x7f60c3d7cda0 <(anonymous namespace)::Q_QGS__q_manager::innerFunction()::holder>) at thread/qthread.cpp:536
#6  0x00007f60c3b04555 in QDBusConnectionManager::run (this=0x7f60c3d7cda0 <(anonymous namespace)::Q_QGS__q_manager::innerFunction()::holder>)
    at qdbusconnection.cpp:179
#7  0x00007f60c26c87ec in QThreadPrivate::start (arg=0x7f60c3d7cda0 <(anonymous namespace)::Q_QGS__q_manager::innerFunction()::holder>) at thread/qthread_unix.cpp:342
#8  0x00007f60c3d856db in start_thread (arg=0x7f60ab3ff700) at pthread_create.c:463
#9  0x00007f60c1d9588f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 1 (Thread 1092.1092):
#0  0x00007f60c401a81d in KWayland::Server::OutputInterface::clientResources(KWayland::Server::ClientConnection*) const ()
   from target:/usr/lib/x86_64-linux-gnu/libKF5WaylandServer.so.5
#1  0x00007f60c40489bc in KWayland::Server::SurfaceInterface::setOutputs(QVector<KWayland::Server::OutputInterface*> const&) ()
   from target:/usr/lib/x86_64-linux-gnu/libKF5WaylandServer.so.5
#2  0x00007f60c549fc90 in KWin::XdgShellClient::updateClientOutputs (this=0x555d00540f30) at ./xdgshellclient.cpp:1951
#3  0x00007f60c28f2fe7 in QtPrivate::QSlotObjectBase::call (a=0x7ffef657e870, r=0x555d00540f30, this=<optimized out>)
    at ../../include/QtCore/../../src/corelib/kernel/qobjectdefs_impl.h:394
#4  doActivate<false> (sender=0x555cffae67a0, signal_index=4, argv=0x7ffef657e870) at kernel/qobject.cpp:3870
#5  0x00007f60c28f2fe7 in QtPrivate::QSlotObjectBase::call (a=0x7ffef657e950, r=0x555cffae67a0, this=<optimized out>)
    at ../../include/QtCore/../../src/corelib/kernel/qobjectdefs_impl.h:394
#6  doActivate<false> (sender=0x555cff9db8e0, signal_index=3, argv=0x7ffef657e950) at kernel/qobject.cpp:3870
#7  0x00007f60c28ed8a2 in QMetaObject::activate (sender=sender@entry=0x555cff9db8e0, m=m@entry=0x7f60c57a5240 <KWin::Platform::staticMetaObject>, 
    local_signal_index=local_signal_index@entry=0, argv=argv@entry=0x0) at kernel/qobject.cpp:3930
#8  0x00007f60c54d1510 in KWin::Platform::screensQueried (this=this@entry=0x555cff9db8e0) at ./obj-x86_64-linux-gnu/kwin_autogen/EWIEGA46WW/moc_platform.cpp:313
#9  0x00007f60aa9cf34e in KWin::DrmBackend::updateOutputs (this=0x555cff9db8e0) at ./plugins/platforms/drm/drm_backend.cpp:505
#10 0x00007f60aa9cff8a in KWin::DrmBackend::<lambda()>::operator() (__closure=0x555cffae6570) at ./plugins/platforms/drm/drm_backend.cpp:374
#11 QtPrivate::FunctorCall<QtPrivate::IndexesList<>, QtPrivate::List<>, void, KWin::DrmBackend::openDrm()::<lambda()> >::call (arg=<optimized out>, f=...)
    at /usr/include/x86_64-linux-gnu/qt5/QtCore/qobjectdefs_impl.h:146
#12 QtPrivate::Functor<KWin::DrmBackend::openDrm()::<lambda()>, 0>::call<QtPrivate::List<>, void> (arg=<optimized out>, f=...)
    at /usr/include/x86_64-linux-gnu/qt5/QtCore/qobjectdefs_impl.h:256
#13 QtPrivate::QFunctorSlotObject<KWin::DrmBackend::openDrm()::<lambda()>, 0, QtPrivate::List<>, void>::impl(int, QtPrivate::QSlotObjectBase *, QObject *, void **, bool *) (which=1, this_=0x555cffae6560, r=<optimized out>, a=<optimized out>, ret=<optimized out>) at /usr/include/x86_64-linux-gnu/qt5/QtCore/qobjectdefs_impl.h:439
#14 0x00007f60c28f2fe7 in QtPrivate::QSlotObjectBase::call (a=0x7ffef657ec10, r=0x555cff9db8e0, this=<optimized out>)
    at ../../include/QtCore/../../src/corelib/kernel/qobjectdefs_impl.h:394
#15 doActivate<false> (sender=0x555cffae6580, signal_index=3, argv=0x7ffef657ec10) at kernel/qobject.cpp:3870
#16 0x00007f60c28ed8a2 in QMetaObject::activate (sender=sender@entry=0x555cffae6580, m=m@entry=0x7f60c2d85bc0 <QSocketNotifier::staticMetaObject>, 
    local_signal_index=local_signal_index@entry=0, argv=argv@entry=0x7ffef657ec10) at kernel/qobject.cpp:3930
#17 0x00007f60c28f65c8 in QSocketNotifier::activated (this=this@entry=0x555cffae6580, _t1=<optimized out>, _t2=...) at .moc/moc_qsocketnotifier.cpp:141
#18 0x00007f60c28f6982 in QSocketNotifier::event (this=0x555cffae6580, e=0x7ffef657eee0) at kernel/qsocketnotifier.cpp:266
#19 0x00007f60c2eeb8bc in QApplicationPrivate::notify_helper (this=this@entry=0x555cff990c80, receiver=receiver@entry=0x555cffae6580, e=e@entry=0x7ffef657eee0)
    at kernel/qapplication.cpp:3684
#20 0x00007f60c2ef2ac0 in QApplication::notify (this=0x7ffef657f2f0, receiver=0x555cffae6580, e=0x7ffef657eee0) at kernel/qapplication.cpp:3430
#21 0x00007f60c28b7db8 in QCoreApplication::notifyInternal2 (receiver=0x555cffae6580, event=0x7ffef657eee0) at kernel/qcoreapplication.cpp:1092
#22 0x00007f60c2914283 in QEventDispatcherUNIXPrivate::activateSocketNotifiers (this=this@entry=0x555cff99ff20) at kernel/qeventdispatcher_unix.cpp:304
#23 0x00007f60c291468f in QEventDispatcherUNIX::processEvents (this=<optimized out>, flags=...) at kernel/qeventdispatcher_unix.cpp:509
#24 0x00007f60ae631c2d in QUnixEventDispatcherQPA::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) ()
   from target:/usr/lib/x86_64-linux-gnu/qt5/plugins/platforms/KWinQpaPlugin.so
#25 0x00007f60c28b663a in QEventLoop::exec (this=this@entry=0x7ffef657f090, flags=..., flags@entry=...) at kernel/qeventloop.cpp:225
#26 0x00007f60c28bfdb0 in QCoreApplication::exec () at kernel/qcoreapplication.cpp:1400
#27 0x0000555cfe4190df in main (argc=<optimized out>, argv=<optimized out>) at ./main_wayland.cpp:679
Detaching from program: target:/usr/bin/kwin_wayland, process 1092
Ending remote debugging.
Comment 2 Thiago Sueto 2021-02-20 20:52:10 UTC 
I can't seem to reproduce this issue on current master.
Comment 3 Patrick Silva 2021-02-23 13:14:54 UTC 
Currently Plasma crashes after the provided steps on neon unstable.
Reported as bug 433486