Bug 413185

Summary: Plasma 5.17 reports crash after login into wayland session
Product: [Plasma] plasmashell Reporter: joern477
Component: generalAssignee: David Edmundson <kde>
Status: RESOLVED FIXED    
Severity: crash CC: fabian, mitchell, plasma-bugs, w.pelser
Priority: NOR Keywords: drkonqi
Version: 5.17.0   
Target Milestone: 1.0   
Platform: Neon   
OS: Linux   
Latest Commit: Version Fixed In:
Attachments: New crash information added by DrKonqi

Description joern477 2019-10-19 11:41:00 UTC 
Application: plasmashell (5.17.0)

Qt Version: 5.13.1
Frameworks Version: 5.63.0
Operating System: Linux 4.15.0-65-generic x86_64
Distribution: KDE neon User Edition 5.17

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

Simply logged in into a wayland session.
Crash symbol is shown in taskbar.  Everything else works fine.

Maybe it is important to note that I have two monitors connected.

The crash can be reproduced every time.

-- Backtrace:
Application: Plasma (plasmashell), signal: Segmentation fault
Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".
[Current thread is 1 (Thread 0x7f54bd2cc800 (LWP 2483))]

Thread 9 (Thread 0x7f5470f4f700 (LWP 2653)):
#0  0x00007f54b40399f3 in futex_wait_cancelable (private=<optimized out>, expected=0, futex_word=0x5616d46f13c0) at ../sysdeps/unix/sysv/linux/futex-internal.h:88
#1  __pthread_cond_wait_common (abstime=0x0, mutex=0x5616d46f1370, cond=0x5616d46f1398) at pthread_cond_wait.c:502
#2  __pthread_cond_wait (cond=0x5616d46f1398, mutex=0x5616d46f1370) at pthread_cond_wait.c:655
#3  0x00007f54b7108b0b in QWaitConditionPrivate::wait (deadline=..., this=0x5616d46f1370) at thread/qwaitcondition_unix.cpp:146
#4  QWaitCondition::wait (this=<optimized out>, mutex=0x5616d465e1f0, deadline=...) at thread/qwaitcondition_unix.cpp:225
#5  0x00007f54b7108e19 in QWaitCondition::wait (this=this@entry=0x5616d465e1f8, mutex=mutex@entry=0x5616d465e1f0, time=time@entry=18446744073709551615) at thread/qwaitcondition_unix.cpp:208
#6  0x00007f54bb127ec8 in QSGRenderThreadEventQueue::takeEvent (wait=true, this=0x5616d465e1e8) at scenegraph/qsgthreadedrenderloop.cpp:245
#7  QSGRenderThread::processEventsAndWaitForMore (this=this@entry=0x5616d465e170) at scenegraph/qsgthreadedrenderloop.cpp:710
#8  0x00007f54bb1282fa in QSGRenderThread::run (this=0x5616d465e170) at scenegraph/qsgthreadedrenderloop.cpp:739
#9  0x00007f54b7101b72 in QThreadPrivate::start (arg=0x5616d465e170) at thread/qthread_unix.cpp:360
#10 0x00007f54b40336db in start_thread (arg=0x7f5470f4f700) at pthread_create.c:463
#11 0x00007f54b69fe88f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 8 (Thread 0x7f5472fff700 (LWP 2652)):
#0  0x00007f54b69ed0b4 in __GI___libc_read (fd=27, buf=0x7f5472ffeb20, nbytes=16) at ../sysdeps/unix/sysv/linux/read.c:27
#1  0x00007f54b09702d0 in ?? () from /usr/lib/x86_64-linux-gnu/libglib-2.0.so.0
#2  0x00007f54b092b0b7 in g_main_context_check () from /usr/lib/x86_64-linux-gnu/libglib-2.0.so.0
#3  0x00007f54b092b570 in ?? () from /usr/lib/x86_64-linux-gnu/libglib-2.0.so.0
#4  0x00007f54b092b6dc in g_main_context_iteration () from /usr/lib/x86_64-linux-gnu/libglib-2.0.so.0
#5  0x00007f54b73449db in QEventDispatcherGlib::processEvents (this=0x7f546c000b20, flags=...) at kernel/qeventdispatcher_glib.cpp:425
#6  0x00007f54b72e4eaa in QEventLoop::exec (this=this@entry=0x7f5472ffed30, flags=..., flags@entry=...) at kernel/qeventloop.cpp:225
#7  0x00007f54b71003ca in QThread::exec (this=this@entry=0x5616d4dfc3d0) at thread/qthread.cpp:531
#8  0x00007f54bb0a1ac6 in QQuickPixmapReader::run (this=0x5616d4dfc3d0) at util/qquickpixmapcache.cpp:962
#9  0x00007f54b7101b72 in QThreadPrivate::start (arg=0x5616d4dfc3d0) at thread/qthread_unix.cpp:360
#10 0x00007f54b40336db in start_thread (arg=0x7f5472fff700) at pthread_create.c:463
#11 0x00007f54b69fe88f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 7 (Thread 0x7f5478e75700 (LWP 2651)):
#0  0x00007f54b40399f3 in futex_wait_cancelable (private=<optimized out>, expected=0, futex_word=0x5616d47e1d14) at ../sysdeps/unix/sysv/linux/futex-internal.h:88
#1  __pthread_cond_wait_common (abstime=0x0, mutex=0x5616d47e1cc0, cond=0x5616d47e1ce8) at pthread_cond_wait.c:502
#2  __pthread_cond_wait (cond=0x5616d47e1ce8, mutex=0x5616d47e1cc0) at pthread_cond_wait.c:655
#3  0x00007f54b7108b0b in QWaitConditionPrivate::wait (deadline=..., this=0x5616d47e1cc0) at thread/qwaitcondition_unix.cpp:146
#4  QWaitCondition::wait (this=<optimized out>, mutex=0x5616d4bde970, deadline=...) at thread/qwaitcondition_unix.cpp:225
#5  0x00007f54b7108e19 in QWaitCondition::wait (this=this@entry=0x5616d4bde978, mutex=mutex@entry=0x5616d4bde970, time=time@entry=18446744073709551615) at thread/qwaitcondition_unix.cpp:208
#6  0x00007f54bb127ec8 in QSGRenderThreadEventQueue::takeEvent (wait=true, this=0x5616d4bde968) at scenegraph/qsgthreadedrenderloop.cpp:245
#7  QSGRenderThread::processEventsAndWaitForMore (this=this@entry=0x5616d4bde8f0) at scenegraph/qsgthreadedrenderloop.cpp:710
#8  0x00007f54bb1282fa in QSGRenderThread::run (this=0x5616d4bde8f0) at scenegraph/qsgthreadedrenderloop.cpp:739
#9  0x00007f54b7101b72 in QThreadPrivate::start (arg=0x5616d4bde8f0) at thread/qthread_unix.cpp:360
#10 0x00007f54b40336db in start_thread (arg=0x7f5478e75700) at pthread_create.c:463
#11 0x00007f54b69fe88f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 6 (Thread 0x7f548127f700 (LWP 2650)):
#0  0x00007f54b40399f3 in futex_wait_cancelable (private=<optimized out>, expected=0, futex_word=0x5616d47e12a4) at ../sysdeps/unix/sysv/linux/futex-internal.h:88
#1  __pthread_cond_wait_common (abstime=0x0, mutex=0x5616d47e1250, cond=0x5616d47e1278) at pthread_cond_wait.c:502
#2  __pthread_cond_wait (cond=0x5616d47e1278, mutex=0x5616d47e1250) at pthread_cond_wait.c:655
#3  0x00007f54b7108b0b in QWaitConditionPrivate::wait (deadline=..., this=0x5616d47e1250) at thread/qwaitcondition_unix.cpp:146
#4  QWaitCondition::wait (this=<optimized out>, mutex=0x5616d47e45c0, deadline=...) at thread/qwaitcondition_unix.cpp:225
#5  0x00007f54b7108e19 in QWaitCondition::wait (this=this@entry=0x5616d47e45c8, mutex=mutex@entry=0x5616d47e45c0, time=time@entry=18446744073709551615) at thread/qwaitcondition_unix.cpp:208
#6  0x00007f54bb127ec8 in QSGRenderThreadEventQueue::takeEvent (wait=true, this=0x5616d47e45b8) at scenegraph/qsgthreadedrenderloop.cpp:245
#7  QSGRenderThread::processEventsAndWaitForMore (this=this@entry=0x5616d47e4540) at scenegraph/qsgthreadedrenderloop.cpp:710
#8  0x00007f54bb1282fa in QSGRenderThread::run (this=0x5616d47e4540) at scenegraph/qsgthreadedrenderloop.cpp:739
#9  0x00007f54b7101b72 in QThreadPrivate::start (arg=0x5616d47e4540) at thread/qthread_unix.cpp:360
#10 0x00007f54b40336db in start_thread (arg=0x7f548127f700) at pthread_create.c:463
#11 0x00007f54b69fe88f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 5 (Thread 0x7f548aa1a700 (LWP 2649)):
#0  0x00007f54b69f1bf9 in __GI___poll (fds=0x7f5484004a10, nfds=1, timeout=8782) at ../sysdeps/unix/sysv/linux/poll.c:29
#1  0x00007f54b092b5c9 in ?? () from /usr/lib/x86_64-linux-gnu/libglib-2.0.so.0
#2  0x00007f54b092b6dc in g_main_context_iteration () from /usr/lib/x86_64-linux-gnu/libglib-2.0.so.0
#3  0x00007f54b73449db in QEventDispatcherGlib::processEvents (this=0x7f5484000b20, flags=...) at kernel/qeventdispatcher_glib.cpp:425
#4  0x00007f54b72e4eaa in QEventLoop::exec (this=this@entry=0x7f548aa19da0, flags=..., flags@entry=...) at kernel/qeventloop.cpp:225
#5  0x00007f54b71003ca in QThread::exec (this=<optimized out>) at thread/qthread.cpp:531
#6  0x00007f54b7101b72 in QThreadPrivate::start (arg=0x5616d44875e0) at thread/qthread_unix.cpp:360
#7  0x00007f54b40336db in start_thread (arg=0x7f548aa1a700) at pthread_create.c:463
#8  0x00007f54b69fe88f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 4 (Thread 0x7f5497fff700 (LWP 2642)):
#0  0x00007f54b40399f3 in futex_wait_cancelable (private=<optimized out>, expected=0, futex_word=0x5616d3effa88) at ../sysdeps/unix/sysv/linux/futex-internal.h:88
#1  __pthread_cond_wait_common (abstime=0x0, mutex=0x5616d3effa38, cond=0x5616d3effa60) at pthread_cond_wait.c:502
#2  __pthread_cond_wait (cond=0x5616d3effa60, mutex=0x5616d3effa38) at pthread_cond_wait.c:655
#3  0x00007f549d6b12cb in ?? () from /usr/lib/x86_64-linux-gnu/dri/i965_dri.so
#4  0x00007f549d6b0ff7 in ?? () from /usr/lib/x86_64-linux-gnu/dri/i965_dri.so
#5  0x00007f54b40336db in start_thread (arg=0x7f5497fff700) at pthread_create.c:463
#6  0x00007f54b69fe88f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 3 (Thread 0x7f54a669b700 (LWP 2612)):
#0  0x00007f54b69f1bf9 in __GI___poll (fds=0x7f5498004e00, nfds=1, timeout=-1) at ../sysdeps/unix/sysv/linux/poll.c:29
#1  0x00007f54b092b5c9 in ?? () from /usr/lib/x86_64-linux-gnu/libglib-2.0.so.0
#2  0x00007f54b092b6dc in g_main_context_iteration () from /usr/lib/x86_64-linux-gnu/libglib-2.0.so.0
#3  0x00007f54b73449db in QEventDispatcherGlib::processEvents (this=0x7f5498000b20, flags=...) at kernel/qeventdispatcher_glib.cpp:425
#4  0x00007f54b72e4eaa in QEventLoop::exec (this=this@entry=0x7f54a669ad80, flags=..., flags@entry=...) at kernel/qeventloop.cpp:225
#5  0x00007f54b71003ca in QThread::exec (this=this@entry=0x5616d3c44aa0) at thread/qthread.cpp:531
#6  0x00007f54babcecb5 in QQmlThreadPrivate::run (this=0x5616d3c44aa0) at qml/ftw/qqmlthread.cpp:152
#7  0x00007f54b7101b72 in QThreadPrivate::start (arg=0x5616d3c44aa0) at thread/qthread_unix.cpp:360
#8  0x00007f54b40336db in start_thread (arg=0x7f54a669b700) at pthread_create.c:463
#9  0x00007f54b69fe88f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 2 (Thread 0x7f54a8513700 (LWP 2496)):
#0  0x00007f54b69f1bf9 in __GI___poll (fds=0x7f54a0003ce0, nfds=1, timeout=-1) at ../sysdeps/unix/sysv/linux/poll.c:29
#1  0x00007f54b092b5c9 in ?? () from /usr/lib/x86_64-linux-gnu/libglib-2.0.so.0
#2  0x00007f54b092b6dc in g_main_context_iteration () from /usr/lib/x86_64-linux-gnu/libglib-2.0.so.0
#3  0x00007f54b73449db in QEventDispatcherGlib::processEvents (this=0x7f54a0000b20, flags=...) at kernel/qeventdispatcher_glib.cpp:425
#4  0x00007f54b72e4eaa in QEventLoop::exec (this=this@entry=0x7f54a8512d70, flags=..., flags@entry=...) at kernel/qeventloop.cpp:225
#5  0x00007f54b71003ca in QThread::exec (this=<optimized out>) at thread/qthread.cpp:531
#6  0x00007f54b83f80e5 in ?? () from /usr/lib/x86_64-linux-gnu/libQt5DBus.so.5
#7  0x00007f54b7101b72 in QThreadPrivate::start (arg=0x7f54b866fd80) at thread/qthread_unix.cpp:360
#8  0x00007f54b40336db in start_thread (arg=0x7f54a8513700) at pthread_create.c:463
#9  0x00007f54b69fe88f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 1 (Thread 0x7f54bd2cc800 (LWP 2483)):
[KCrash Handler]
#6  QExplicitlySharedDataPointer<KConfigGroupPrivate>::operator bool (this=0x18) at /usr/include/x86_64-linux-gnu/qt5/QtCore/qshareddata.h:174
#7  KConfigGroup::parent (this=this@entry=0x7ffd320e4bb0) at ./src/core/kconfiggroup.cpp:558
#8  0x00005616d1e88b9d in PanelView::restore (this=this@entry=0x5616d53e0c80) at ./shell/panelview.cpp:574
#9  0x00005616d1e88fa4 in PanelView::containmentChanged (this=0x5616d53e0c80) at ./shell/panelview.cpp:1177
#10 0x00005616d1e89545 in PanelView::qt_static_metacall (_o=0x5616d53e0c80, _c=<optimized out>, _id=<optimized out>, _a=0x7ffd320e4db0) at ./obj-x86_64-linux-gnu/shell/plasmashell_autogen/include/moc_panelview.cpp:258
#11 0x00007f54b7317715 in QMetaObject::activate (sender=0x5616d53e0c80, signalOffset=<optimized out>, local_signal_index=local_signal_index@entry=2, argv=<optimized out>, argv@entry=0x0) at kernel/qobject.cpp:3809
#12 0x00007f54b7317dd7 in QMetaObject::activate (sender=<optimized out>, m=m@entry=0x7f54bd0fba40 <PlasmaQuick::ContainmentView::staticMetaObject>, local_signal_index=local_signal_index@entry=2, argv=argv@entry=0x0) at kernel/qobject.cpp:3660
#13 0x00007f54bced5153 in PlasmaQuick::ContainmentView::containmentChanged (this=<optimized out>) at ./obj-x86_64-linux-gnu/src/plasmaquick/KF5PlasmaQuick_autogen/include/moc_containmentview.cpp:267
#14 0x00007f54bced5615 in PlasmaQuick::ContainmentViewPrivate::setContainment (this=0x5616d3c91c50, cont=0x5616d3f7e6f0) at ./src/plasmaquick/containmentview.cpp:93
#15 0x00007f54bced60e9 in PlasmaQuick::ContainmentView::setContainment (this=this@entry=0x5616d53e0c80, cont=<optimized out>) at ./src/plasmaquick/containmentview.cpp:256
#16 0x00005616d1e95f8e in ShellCorona::createWaitingPanels (this=0x5616d3b91b30) at ./shell/shellcorona.cpp:1328
#17 0x00007f54b731782f in QtPrivate::QSlotObjectBase::call (a=0x7ffd320e5150, r=0x5616d3b91b30, this=<optimized out>) at ../../include/QtCore/../../src/corelib/kernel/qobjectdefs_impl.h:394
#18 QMetaObject::activate (sender=sender@entry=0x5616d3b91be8, signalOffset=<optimized out>, local_signal_index=local_signal_index@entry=0, argv=<optimized out>, argv@entry=0x7ffd320e5150) at kernel/qobject.cpp:3789
#19 0x00007f54b7317dd7 in QMetaObject::activate (sender=sender@entry=0x5616d3b91be8, m=m@entry=0x7f54b779cd80 <QTimer::staticMetaObject>, local_signal_index=local_signal_index@entry=0, argv=argv@entry=0x7ffd320e5150) at kernel/qobject.cpp:3660
#20 0x00007f54b7324447 in QTimer::timeout (this=this@entry=0x5616d3b91be8, _t1=...) at .moc/moc_qtimer.cpp:205
#21 0x00007f54b73247a8 in QTimer::timerEvent (this=0x5616d3b91be8, e=<optimized out>) at kernel/qtimer.cpp:255
#22 0x00007f54b731822b in QObject::event (this=0x5616d3b91be8, e=<optimized out>) at kernel/qobject.cpp:1282
#23 0x00007f54b8c4deac in QApplicationPrivate::notify_helper (this=this@entry=0x5616d3b54fb0, receiver=receiver@entry=0x5616d3b91be8, e=e@entry=0x7ffd320e54c0) at kernel/qapplication.cpp:3703
#24 0x00007f54b8c554b0 in QApplication::notify (this=0x7ffd320e5860, receiver=0x5616d3b91be8, e=0x7ffd320e54c0) at kernel/qapplication.cpp:3449
#25 0x00007f54b72e6d48 in QCoreApplication::notifyInternal2 (receiver=0x5616d3b91be8, event=0x7ffd320e54c0) at kernel/qcoreapplication.cpp:1095
#26 0x00007f54b7343e49 in QTimerInfoList::activateTimers (this=0x5616d3b83170) at kernel/qtimerinfo_unix.cpp:643
#27 0x00007f54b7344611 in timerSourceDispatch (source=<optimized out>) at kernel/qeventdispatcher_glib.cpp:183
#28 0x00007f54b092b417 in g_main_context_dispatch () from /usr/lib/x86_64-linux-gnu/libglib-2.0.so.0
#29 0x00007f54b092b650 in ?? () from /usr/lib/x86_64-linux-gnu/libglib-2.0.so.0
#30 0x00007f54b092b6dc in g_main_context_iteration () from /usr/lib/x86_64-linux-gnu/libglib-2.0.so.0
#31 0x00007f54b73449bf in QEventDispatcherGlib::processEvents (this=0x5616d3b752e0, flags=...) at kernel/qeventdispatcher_glib.cpp:423
#32 0x00007f54b72e4eaa in QEventLoop::exec (this=this@entry=0x7ffd320e5710, flags=..., flags@entry=...) at kernel/qeventloop.cpp:225
#33 0x00007f54b72ee220 in QCoreApplication::exec () at kernel/qcoreapplication.cpp:1403
#34 0x00005616d1e76cef in main (argc=<optimized out>, argv=<optimized out>) at ./shell/main.cpp:219

Possible duplicates by query: bug 413170, bug 413166, bug 413064, bug 413011, bug 412947.

Reported using DrKonqi
Comment 1 mitchell 2019-10-20 03:03:39 UTC 
Created attachment 123347 [details]
New crash information added by DrKonqi

plasmashell (5.17.0) using Qt 5.13.1

- What I was doing when the application crashed:
Login to wayland session
- Custom settings of the application:
Nvidia PC, using Kwin's EGLStreams support.

-- Backtrace (Reduced):
#6  0x00007f10e5e56a52 in  () at /usr/lib/libnvidia-egl-wayland.so.1
#7  0x00007f10ecfd6183 in wl_egl_window_destroy () at /usr/lib/libwayland-egl.so.1
#8  0x00007f10e657188b in  () at /usr/lib/qt/plugins/wayland-graphics-integration-client/libqt-plugin-wayland-egl.so
#9  0x00007f10f2728aac in QWindowPrivate::setVisible(bool) () at /usr/lib/libQt5Gui.so.5
#10 0x00007f10f2727ed9 in QWindowPrivate::destroy() () at /usr/lib/libQt5Gui.so.5
Comment 2 Walther Pelser 2019-10-20 08:28:26 UTC 
Yesterday I reported  a similar bug to openSUSE. https://bugzilla.suse.com/show_bug.cgi?id=1154535, sddm cant start wayland. maybe it is the same problem.
I was asked to report it to bugs.kde.org.
OS: openSUSE-Tumbleweed current
Plasma-Version 5.17
QT-Version 5.13.1

The problems began with the latest updates of plasma on 2019-10-16

This is the text of the description:

Sddm can start only x-session
Blackcreen when sddm tries to start wayland or fullwayland. Reboot necessary.
Systemdjounal shows: kernel	kwin_wayland[6442]: segfault at 10 ip 00007f4adc4c0c30 sp 00007ffe7192ff08 error 4 in libKF5WaylandServer.so.5.63.0[7f4adc49b000+60000]
See attachment systemd backtrace.txt
I tried everything, but could not repair this. There are a lot of customizations maybe there could be a connection.
When I start an x-session and execute in a terminal: env GDK_BACKEND=wayland QT_QPA_PLATFORM=wayland dbus-run-session /usr/bin/startplasma-wayland  wayland is starting.

Attachment in full text:
19.10.19 10:14	systemd-logind	New session 6 of user walther.
19.10.19 10:14	systemd	Started Session 6 of user walther.
19.10.19 10:14	sddm-helper	pam_unix(sddm:session): session opened for user walther(uid=1000) by (uid=0)
19.10.19 10:14	sddm-helper	Starting: "/usr/share/sddm/scripts/wayland-session env GDK_BACKEND=wayland QT_QPA_PLATFORM=wayland-egl dbus-run-session /usr/bin/startplasma-wayland"
19.10.19 10:14	sddm	Session started
19.10.19 10:14	dbus-daemon	[system] Activating via systemd: service name='org.freedesktop.locale1' unit='dbus-org.freedesktop.locale1.service' requested by ':1.135' (uid=1000 pid=6437 comm="/usr/bin/startplasma-wayland ")
19.10.19 10:14	systemd	Starting Locale Service...
19.10.19 10:14	dbus-daemon	[system] Successfully activated service 'org.freedesktop.locale1'
19.10.19 10:14	systemd	Started Locale Service.
19.10.19 10:14	kernel	show_signal_msg: 40 callbacks suppressed
19.10.19 10:14	kernel	kwin_wayland[6442]: segfault at 10 ip 00007f4adc4c0c30 sp 00007ffe7192ff08 error 4 in libKF5WaylandServer.so.5.63.0[7f4adc49b000+60000]
19.10.19 10:14	kernel	Code: 00 00 c3 0f 1f 80 00 00 00 00 48 85 f6 74 0b 48 89 f7 e9 33 a9 fd ff 0f 1f 00 c3 90 66 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 <48> 8b 47 10 c3 90 66 2e 0f 1f 84 00 00 00 00 00 48 83 ec 08 e8 e7
19.10.19 10:14	systemd	Created slice system-systemd\x2dcoredump.slice.
19.10.19 10:14	systemd	Started Process Core Dump (PID 6446/UID 0).
19.10.19 10:14	sddm-helper	[PAM] Closing session
19.10.19 10:14	systemd-logind	Failed to restore VT, ignoring: Input/output error
19.10.19 10:14	sddm-helper	pam_unix(sddm:session): session closed for user walther
19.10.19 10:14	sddm-helper	[PAM] Ended.
19.10.19 10:14	sddm	Auth: sddm-helper exited successfully
19.10.19 10:14	sddm	Greeter stopping...
19.10.19 10:14	sddm	Socket server stopping...
19.10.19 10:14	sddm	Socket server stopped.
19.10.19 10:14	sddm	Display server stopping...
19.10.19 10:14	sddm-greeter	The X11 connection broke: I/O error (code 1)
19.10.19 10:14	sddm-helper	[PAM] Closing session
19.10.19 10:14	systemd-coredump	Process 6442 (kwin_wayland) of user 1000 dumped core.

Stack trace of thread 6442:
#0  0x00007f4adc4c0c30 _ZNK8KWayland6Server21OutputDeviceInterface6d_funcEv (libKF5WaylandServer.so.5)
#1  0x00007f4adc4c0c49 _ZNK8KWayland6Server21OutputDeviceInterface9pixelSizeEv (libKF5WaylandServer.so.5)
#2  0x00007f4adc7cd761 _ZNK4KWin21AbstractWaylandOutput9pixelSizeEv (libkwin.so.5)
#3  0x00007f4ad4845991 n/a (KWinWaylandDrmBackend.so)
#4  0x00007f4ad484d451 _ZN4KWin9DrmOutput4initEP17_drmModeConnector (KWinWaylandDrmBackend.so)
#5  0x00007f4ad483efd9 _ZN4KWin10DrmBackend13updateOutputsEv (KWinWaylandDrmBackend.so)
#6  0x00007f4ad484061d _ZN4KWin10DrmBackend7openDrmEv (KWinWaylandDrmBackend.so)
#7  0x00007f4adb93b638 _ZN11QMetaObject8activateEP7QObjectiiPPv (libQt5Core.so.5)
#8  0x00007f4adc7a4052 _ZN4KWin17LogindIntegration24hasSessionControlChangedEb (libkwin.so.5)
#9  0x00007f4adc88b730 n/a (libkwin.so.5)
#10 0x00007f4adb93b638 _ZN11QMetaObject8activateEP7QObjectiiPPv (libQt5Core.so.5)
#11 0x00007f4adc3ee93f _ZN23QDBusPendingCallWatcher8finishedEPS_ (libQt5DBus.so.5)
#12 0x00007f4adc3eea40 n/a (libQt5DBus.so.5)
#13 0x00007f4adb93beea _ZN7QObject5eventEP6QEvent (libQt5Core.so.5)
#14 0x00007f4adbd51c62 _ZN19QApplicationPrivate13notify_helperEP7QObjectP6QEvent (libQt5Widgets.so.5)
#15 0x00007f4adbd5b1e0 _ZN12QApplication6notifyEP7QObjectP6QEvent (libQt5Widgets.so.5)
#16 0x00007f4adb910572 _ZN16QCoreApplication15notifyInternal2EP7QObjectP6QEvent (libQt5Core.so.5)
#17 0x00007f4adb913208 _ZN23QCoreApplicationPrivate16sendPostedEventsEP7QObjectiP11QThreadData (libQt5Core.so.5)
#18 0x00007f4adb963db3 _ZN20QEventDispatcherUNIX13processEventsE6QFlagsIN10QEventLoop17ProcessEventsFlagEE (libQt5Core.so.5)
#19 0x00007f4ad593b6fd n/a (KWinQpaPlugin.so)
#20 0x00007f4adb90f0db _ZN10QEventLoop4execE6QFlagsINS_17ProcessEventsFlagEE (libQt5Core.so.5)
#21 0x00007f4adb916d42 _ZN16QCoreApplication4execEv (libQt5Core.so.5)
#22 0x0000555b77330415 n/a (kwin_wayland)
#23 0x00007f4adb2cbe0b __libc_start_main (libc.so.6)
#24 0x0000555b7733085a _start (kwin_wayland)

Stack trace of thread 6443:
#0  0x00007f4adb399bdf __poll (libc.so.6)
#1  0x00007f4ad8dda3ce n/a (libglib-2.0.so.0)
#2  0x00007f4ad8dda49f g_main_context_iteration (libglib-2.0.so.0)
#3  0x00007f4adb966981 _ZN20QEventDispatcherGlib13processEventsE6QFlagsIN10QEventLoop17ProcessEventsFlagEE (libQt5Core.so.5)
#4  0x00007f4adb90f0db _ZN10QEventLoop4execE6QFlagsINS_17ProcessEventsFlagEE (libQt5Core.so.5)
#5  0x00007f4adb747021 _ZN7QThread4execEv (libQt5Core.so.5)
#6  0x00007f4adc38c4f6 n/a (libQt5DBus.so.5)
#7  0x00007f4adb7481a2 n/a (libQt5Core.so.5)
#8  0x00007f4adc418f2a start_thread (libpthread.so.0)
#9  0x00007f4adb3a44af __clone (libc.so.6)

Stack trace of thread 6445:
#0  0x00007f4adb399bdf __poll (libc.so.6)
#1  0x00007f4ad8dda3ce n/a (libglib-2.0.so.0)
#2  0x00007f4ad8dda49f g_main_context_iteration (libglib-2.0.so.0)
#3  0x00007f4adb966981 _ZN20QEventDispatcherGlib13processEventsE6QFlagsIN10QEventLoop17ProcessEventsFlagEE (libQt5Core.so.5)
#4  0x00007f4adb90f0db _ZN10QEventLoop4execE6QFlagsINS_17ProcessEventsFlagEE (libQt5Core.so.5)
#5  0x00007f4adb747021 _ZN7QThread4execEv (libQt5Core.so.5)
#6  0x00007f4adb7481a2 n/a (libQt5Core.so.5)
#7  0x00007f4adc418f2a start_thread (libpthread.so.0)
#8  0x00007f4adb3a44af __clone (libc.so.6)

Stack trace of thread 6444:
#0  0x00007f4adb399bdf __poll (libc.so.6)
#1  0x00007f4ad8dda3ce n/a (libglib-2.0.so.0)
#2  0x00007f4ad8dda49f g_main_context_iteration (libglib-2.0.so.0)
#3  0x00007f4adb966981 _ZN20QEventDispatcherGlib13processEventsE6QFlagsIN10QEventLoop17ProcessEventsFlagEE (libQt5Core.so.5)
#4  0x00007f4adb90f0db _ZN10QEventLoop4execE6QFlagsINS_17ProcessEventsFlagEE (libQt5Core.so.5)
#5  0x00007f4adb747021 _ZN7QThread4execEv (libQt5Core.so.5)
#6  0x00007f4adb7481a2 n/a (libQt5Core.so.5)
#7  0x00007f4adc418f2a start_thread (libpthread.so.0)
#8  0x00007f4adb3a44af __clone (libc.so.6)
Comment 3 Walther Pelser 2019-10-23 09:30:42 UTC 
It seems, that with Kwin 5.17.1 my problem is solved. Sddm can start wayland again.
Comment 4 joern477 2019-10-23 10:58:59 UTC 
For me it also seems to be solved with Plasma 5.17.1 on KDE Neon user.
Tested several login / logouts without any crash reported.

Since Plasma 5.17 I can finally use wayland session as daily driver with dual Monitor setup :-)
Thank you all for the amazing work!
Comment 5 joern477 2019-11-01 21:55:11 UTC 
fixed with Plasma 5.17.1