Bug 395706

Summary: Dual monitor + wayland crash
Product: [Plasma] plasmashell Reporter: Tom Magowan <tom.magowan>
Component: generalAssignee: David Edmundson <kde>
Status: RESOLVED BACKTRACE    
Severity: crash CC: notmart, plasma-bugs-null
Priority: NOR Keywords: drkonqi
Version First Reported In: 5.13.1   
Target Milestone: 1.0   
Platform: Neon   
OS: Linux   
Latest Commit: Version Fixed/Implemented In:
Sentry Crash Report:
Attachments: unstable config from ~/.local/share/kscreen

Description Tom Magowan 2018-06-21 21:30:37 UTC 
Application: plasmashell (5.13.1)

Qt Version: 5.11.0
Frameworks Version: 5.47.0
Operating System: Linux 4.13.0-45-generic x86_64
Distribution: KDE neon User Edition 5.13

-- Information about the crash:
System: Dell XPS laptop with connected external monitor.

- What I was doing when the application crashed:
Log in to kde using plasma wayland session.
After a few seconds the laptop display freezes, but the external monitor loads the kde desktop.
The System Compositor dialog is launched.
Crash report icon displayed in system tray (used to generate this bug report).
The system display dialog reports the laptop monitor as disabled, the external monitor as enabled.

This crash also happens on another Dell XPS laptop of mine. I first noticed the issue with the release of plasma 5.12 LTS, and it continues to be an issue in 5.13.1

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 0x7f264a983940 (LWP 24118))]

Thread 6 (Thread 0x7f258bfff700 (LWP 24190)):
#0  0x00007f2643b2474d in poll () at ../sysdeps/unix/syscall-template.S:84
#1  0x00007f263df3c38c in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#2  0x00007f263df3c49c in g_main_context_iteration () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#3  0x00007f264443bbeb in QEventDispatcherGlib::processEvents (this=0x7f25840008c0, flags=...) at kernel/qeventdispatcher_glib.cpp:425
#4  0x00007f26443e31ca in QEventLoop::exec (this=this@entry=0x7f258bffec00, flags=..., flags@entry=...) at kernel/qeventloop.cpp:214
#5  0x00007f26442185e4 in QThread::exec (this=<optimized out>) at thread/qthread.cpp:522
#6  0x00007f26481dce66 in ?? () from /usr/lib/x86_64-linux-gnu/libQt5Quick.so.5
#7  0x00007f2644223727 in QThreadPrivate::start (arg=0x1bfe140) at thread/qthread_unix.cpp:367
#8  0x00007f26430c86ba in start_thread (arg=0x7f258bfff700) at pthread_create.c:333
#9  0x00007f2643b3041d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

Thread 5 (Thread 0x7f259a2a3700 (LWP 24188)):
#0  pthread_cond_wait@@GLIBC_2.3.2 () at ../sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S:185
#1  0x00007f26442245cb in QWaitConditionPrivate::wait (time=18446744073709551615, this=0x19d71e0) at thread/qwaitcondition_unix.cpp:143
#2  QWaitCondition::wait (this=<optimized out>, mutex=0x19d5440, time=18446744073709551615) at thread/qwaitcondition_unix.cpp:215
#3  0x00007f264825cafd in ?? () from /usr/lib/x86_64-linux-gnu/libQt5Quick.so.5
#4  0x00007f264825cf81 in ?? () from /usr/lib/x86_64-linux-gnu/libQt5Quick.so.5
#5  0x00007f2644223727 in QThreadPrivate::start (arg=0x19d53c0) at thread/qthread_unix.cpp:367
#6  0x00007f26430c86ba in start_thread (arg=0x7f259a2a3700) at pthread_create.c:333
#7  0x00007f2643b3041d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

Thread 4 (Thread 0x7f262b7cf700 (LWP 24178)):
#0  pthread_cond_wait@@GLIBC_2.3.2 () at ../sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S:185
#1  0x00007f264a0f0e04 in ?? () from /usr/lib/x86_64-linux-gnu/libQt5Script.so.5
#2  0x00007f264a0f0e49 in ?? () from /usr/lib/x86_64-linux-gnu/libQt5Script.so.5
#3  0x00007f26430c86ba in start_thread (arg=0x7f262b7cf700) at pthread_create.c:333
#4  0x00007f2643b3041d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

Thread 3 (Thread 0x7f2631e71700 (LWP 24160)):
#0  0x00007f2643b2474d in poll () at ../sysdeps/unix/syscall-template.S:84
#1  0x00007f263df3c38c in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#2  0x00007f263df3c49c in g_main_context_iteration () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#3  0x00007f264443bbeb in QEventDispatcherGlib::processEvents (this=0x7f26240008c0, flags=...) at kernel/qeventdispatcher_glib.cpp:425
#4  0x00007f26443e31ca in QEventLoop::exec (this=this@entry=0x7f2631e70c50, flags=..., flags@entry=...) at kernel/qeventloop.cpp:214
#5  0x00007f26442185e4 in QThread::exec (this=<optimized out>) at thread/qthread.cpp:522
#6  0x00007f2647d52cf5 in ?? () from /usr/lib/x86_64-linux-gnu/libQt5Qml.so.5
#7  0x00007f2644223727 in QThreadPrivate::start (arg=0x102e5d0) at thread/qthread_unix.cpp:367
#8  0x00007f26430c86ba in start_thread (arg=0x7f2631e71700) at pthread_create.c:333
#9  0x00007f2643b3041d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

Thread 2 (Thread 0x7f26338a7700 (LWP 24147)):
#0  0x00007f2643b2474d in poll () at ../sysdeps/unix/syscall-template.S:84
#1  0x00007f263df3c38c in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#2  0x00007f263df3c49c in g_main_context_iteration () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#3  0x00007f264443bbeb in QEventDispatcherGlib::processEvents (this=0x7f262c0008c0, flags=...) at kernel/qeventdispatcher_glib.cpp:425
#4  0x00007f26443e31ca in QEventLoop::exec (this=this@entry=0x7f26338a6c40, flags=..., flags@entry=...) at kernel/qeventloop.cpp:214
#5  0x00007f26442185e4 in QThread::exec (this=<optimized out>) at thread/qthread.cpp:522
#6  0x00007f2646783f35 in ?? () from /usr/lib/x86_64-linux-gnu/libQt5DBus.so.5
#7  0x00007f2644223727 in QThreadPrivate::start (arg=0x7f26469fcd60) at thread/qthread_unix.cpp:367
#8  0x00007f26430c86ba in start_thread (arg=0x7f26338a7700) at pthread_create.c:333
#9  0x00007f2643b3041d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

Thread 1 (Thread 0x7f264a983940 (LWP 24118)):
[KCrash Handler]
#6  0x0000000000000080 in ?? ()
#7  0x00007f26449aa5f1 in QGuiApplicationPrivate::processActivatedEvent (e=0x17c0890) at kernel/qguiapplication.cpp:2260
#8  0x00007f26449aaa8d in QGuiApplicationPrivate::processWindowSystemEvent (e=e@entry=0x17c0890) at kernel/qguiapplication.cpp:1827
#9  0x00007f2644982dfb in QWindowSystemInterface::sendWindowSystemEvents (flags=...) at kernel/qwindowsysteminterface.cpp:1028
#10 0x00007f2635e7ce6b in QPAEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/x86_64-linux-gnu/libQt5WaylandClient.so.5
#11 0x00007f26443e31ca in QEventLoop::exec (this=this@entry=0x7ffeeced93e0, flags=..., flags@entry=...) at kernel/qeventloop.cpp:214
#12 0x00007f26443ec2d4 in QCoreApplication::exec () at kernel/qcoreapplication.cpp:1336
#13 0x000000000041da25 in main (argc=1, argv=<optimized out>) at /workspace/build/shell/main.cpp:212

Possible duplicates by query: bug 395570, bug 385440, bug 384226, bug 383468.

Reported using DrKonqi
Comment 1 Marco Martin 2018-06-22 11:39:07 UTC 
not very useful bt, can this be reproduced with full debug symbols?
Comment 2 Tom Magowan 2018-06-25 18:13:03 UTC 
Created attachment 113563 [details]
unstable config from ~/.local/share/kscreen
Comment 3 Tom Magowan 2018-06-25 18:21:04 UTC 
Apologies for the lack of debug symbols, DrKonqi implied they had been installed.

Unfortunately I cannot reproduce the exact same crash (the problem manifests itself slightly differently every time I log in). However I did manage to find the root cause of the issue, which I believe to be a problematic kscreen configuration. If I delete the directory ~/.local/share/kscreen I can log in fine, and the plasma wayland session is created successfully.

I've attached the unstable kscreen config to this bug report, just in case it helps.