Bug 401590

Summary: Kwin crashed when triggering Corner event (Present Windows/Desktop grid)
Product: [Plasma] kwin Reporter: flyos
Component: generalAssignee: KWin default assignee <kwin-bugs-null>
Status: RESOLVED DUPLICATE    
Severity: crash CC: paulo76.algarve
Priority: NOR Keywords: drkonqi
Version First Reported In: 5.14.4   
Target Milestone: ---   
Platform: openSUSE   
OS: Linux   
Latest Commit: Version Fixed/Implemented In:
Sentry Crash Report:

Description flyos 2018-11-30 20:34:56 UTC 
Application: kwin_x11 (5.14.4)

Qt Version: 5.11.2
Frameworks Version: 5.52.0
Operating System: Linux 4.12.14-lp150.12.25-default x86_64
Distribution: "openSUSE Leap 15.0"

-- Information about the crash:
- What I was doing when the application crashed:
Aiming for a notification to close it and reached the corner of the Desktop which should have triggered either Present Windows or Desktop Grid. Kwin crashed at the exact time the blue shadow for the corner event appeared.

- Unusual behavior I noticed:
My KWin is subject to numerous freezes which I never was able to pinpoint the origin of (triggered more often when CPU is used). It might be totally unrelated, but it is a unusual behaviour worth reporting here I guess...

-- Backtrace:
Application: KWin (kwin_x11), signal: Segmentation fault
Using host libthread_db library "/lib64/libthread_db.so.1".
[Current thread is 1 (Thread 0x7f6545563940 (LWP 20673))]

Thread 5 (Thread 0x7f6523baa700 (LWP 21278)):
#0  0x00007f65424b3a60 in QTimerInfoList::repairTimersIfNeeded() () at /usr/lib64/libQt5Core.so.5
#1  0x00007f65424b3af3 in QTimerInfoList::timerWait(timespec&) () at /usr/lib64/libQt5Core.so.5
#2  0x00007f65424b2ae4 in QEventDispatcherUNIX::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib64/libQt5Core.so.5
#3  0x00007f654245970a in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib64/libQt5Core.so.5
#4  0x00007f6542284aaa in QThread::exec() () at /usr/lib64/libQt5Core.so.5
#5  0x00007f653c957015 in  () at /usr/lib64/libQt5Qml.so.5
#6  0x00007f654228f9cb in  () at /usr/lib64/libQt5Core.so.5
#7  0x00007f653dec9559 in start_thread () at /lib64/libpthread.so.0
#8  0x00007f6544ee881f in clone () at /lib64/libc.so.6

Thread 4 (Thread 0x7f6506739700 (LWP 20680)):
#0  0x00007f653decf89d in pthread_cond_wait@@GLIBC_2.3.2 () at /lib64/libpthread.so.0
#1  0x00007f654118e6f4 in  () at /usr/lib64/libQt5Script.so.5
#2  0x00007f654118e739 in  () at /usr/lib64/libQt5Script.so.5
#3  0x00007f653dec9559 in start_thread () at /lib64/libpthread.so.0
#4  0x00007f6544ee881f in clone () at /lib64/libc.so.6

Thread 3 (Thread 0x7f652187e700 (LWP 20677)):
#0  0x00007f6544ede176 in ppoll () at /lib64/libc.so.6
#1  0x00007f65424b10d1 in qt_safe_poll(pollfd*, unsigned long, timespec const*) () at /usr/lib64/libQt5Core.so.5
#2  0x00007f65424b27de in QEventDispatcherUNIX::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib64/libQt5Core.so.5
#3  0x00007f654245970a in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib64/libQt5Core.so.5
#4  0x00007f6542284aaa in QThread::exec() () at /usr/lib64/libQt5Core.so.5
#5  0x00007f653c957015 in  () at /usr/lib64/libQt5Qml.so.5
#6  0x00007f654228f9cb in  () at /usr/lib64/libQt5Core.so.5
#7  0x00007f653dec9559 in start_thread () at /lib64/libpthread.so.0
#8  0x00007f6544ee881f in clone () at /lib64/libc.so.6

Thread 2 (Thread 0x7f6528843700 (LWP 20675)):
#0  0x00007f6544ede176 in ppoll () at /lib64/libc.so.6
#1  0x00007f65424b10d1 in qt_safe_poll(pollfd*, unsigned long, timespec const*) () at /usr/lib64/libQt5Core.so.5
#2  0x00007f65424b27de in QEventDispatcherUNIX::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib64/libQt5Core.so.5
#3  0x00007f654245970a in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib64/libQt5Core.so.5
#4  0x00007f6542284aaa in QThread::exec() () at /usr/lib64/libQt5Core.so.5
#5  0x00007f653b82cb75 in  () at /usr/lib64/libQt5DBus.so.5
#6  0x00007f654228f9cb in  () at /usr/lib64/libQt5Core.so.5
#7  0x00007f653dec9559 in start_thread () at /lib64/libpthread.so.0
#8  0x00007f6544ee881f in clone () at /lib64/libc.so.6

Thread 1 (Thread 0x7f6545563940 (LWP 20673)):
[KCrash Handler]
#6  0x00007f6544a0ca09 in std::__find_if<int const*, __gnu_cxx::__ops::_Iter_equals_val<int const> >(int const*, int const*, __gnu_cxx::__ops::_Iter_equals_val<int const>, std::random_access_iterator_tag) (__pred=..., __last=0x1561190a68353, __first=0x1561190a67f7f) at /usr/include/c++/7/bits/stl_algo.h:120
#7  0x00007f6544a0ca09 in std::__find_if<int const*, __gnu_cxx::__ops::_Iter_equals_val<int const> >(int const*, int const*, __gnu_cxx::__ops::_Iter_equals_val<int const>) (__pred=..., __last=<optimized out>, __first=<optimized out>) at /usr/include/c++/7/bits/stl_algo.h:162
#8  0x00007f6544a0ca09 in std::find<int const*, int>(int const*, int const*, int const&) (__val=@0x7ffee8dc9c48: 6, __last=<optimized out>, __first=<optimized out>) at /usr/include/c++/7/bits/stl_algo.h:3908
#9  0x00007f6544a0ca09 in QVector<int>::contains(int const&) const (this=this@entry=0x7ffee8dc9c50, t=@0x7ffee8dc9c48: 6) at /usr/include/qt5/QtCore/qvector.h:936
#10 0x00007f6544a0b487 in KWin::Workspace::workspaceEvent(xcb_generic_event_t*) (this=0x56108b52e290, e=0x7f652401f2c0) at /usr/src/debug/kwin5-5.14.4-lp150.270.1.x86_64/events.cpp:240
#11 0x00007f654245829f in QAbstractEventDispatcher::filterNativeEvent(QByteArray const&, void*, long*) () at /usr/lib64/libQt5Core.so.5
#12 0x00007f652c43a720 in QXcbConnection::handleXcbEvent(xcb_generic_event_t*) () at /usr/lib64/libQt5XcbQpa.so.5
#13 0x00007f652c43b37c in QXcbConnection::processXcbEvents() () at /usr/lib64/libQt5XcbQpa.so.5
#14 0x00007f654248af62 in QObject::event(QEvent*) () at /usr/lib64/libQt5Core.so.5
#15 0x00007f6543231f9c in QApplicationPrivate::notify_helper(QObject*, QEvent*) () at /usr/lib64/libQt5Widgets.so.5
#16 0x00007f654323957f in QApplication::notify(QObject*, QEvent*) () at /usr/lib64/libQt5Widgets.so.5
#17 0x00007f654245b3d8 in QCoreApplication::notifyInternal2(QObject*, QEvent*) () at /usr/lib64/libQt5Core.so.5
#18 0x00007f654245df1d in QCoreApplicationPrivate::sendPostedEvents(QObject*, int, QThreadData*) () at /usr/lib64/libQt5Core.so.5
#19 0x00007f65424b25f4 in QEventDispatcherUNIX::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib64/libQt5Core.so.5
#20 0x00007f652c4c68bd in  () at /usr/lib64/libQt5XcbQpa.so.5
#21 0x00007f654245970a in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib64/libQt5Core.so.5
#22 0x00007f65424628c0 in QCoreApplication::exec() () at /usr/lib64/libQt5Core.so.5
#23 0x00007f65451b360b in kdemain(int, char**) (argc=<optimized out>, argv=0x7ffee8dca538) at /usr/src/debug/kwin5-5.14.4-lp150.270.1.x86_64/main_x11.cpp:468
#24 0x00007f6544e10f4a in __libc_start_main () at /lib64/libc.so.6
#25 0x0000561089bcd7fa in _start () at ../sysdeps/x86_64/start.S:120
[Inferior 1 (process 20673) detached]

Possible duplicates by query: bug 398977.

Reported using DrKonqi
Comment 1 Vlad Zahorodnii 2018-12-05 18:13:43 UTC 
How often does this happen?
Comment 2 flyos 2018-12-07 12:27:30 UTC 
It happened a few times, but it's too rare to test how to replicate this, unfortunately. The freezes are more frequent, but not associated to a backtrace unfortunately, so definitely not possible to replicate and possibly unrelated to this crash.
Comment 3 Vlad Zahorodnii 2019-01-07 10:51:11 UTC 
*** Bug 402769 has been marked as a duplicate of this bug. ***
Comment 4 Vlad Zahorodnii 2019-02-15 10:21:19 UTC 
Okay, so the crash happens somewhere here

        foreach (X11EventFilter *filter, m_eventFilters) {
            if (filter->eventTypes().contains(eventType) && filter->event(e)) {
                return true;
            }
        }

I wonder how QVector::contains could crash here.
Comment 5 Vlad Zahorodnii 2019-02-15 10:44:01 UTC 

*** This bug has been marked as a duplicate of bug 398977 ***
Comment 6 Vlad Zahorodnii 2019-02-22 14:11:36 UTC 
What gpu do you have on your machine? Also, could you please share your desktop layout, e.g. where is panel, is it auto-hidden, etc?