Bug 437457

Application: kwin_x11 (5.18.5)

Qt Version: 5.12.8
Frameworks Version: 5.68.0
Operating System: Linux 5.8.0-53-lowlatency x86_64
Windowing system: X11
Distribution: Ubuntu 20.04.2 LTS

-- Information about the crash:
- What I was doing when the application crashed:
I moved the mouse cursor to the top-left screen edge to show the overview with the windows. I moved it several times, hiding and unhiding the windows. Then the screen (it might have just been the active application window, or just the taskbar, don't remember) flickered black once and the crash reporter appeared.

-- Backtrace:
Application: KWin (kwin_x11), signal: Segmentation fault
Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".
[Current thread is 1 (Thread 0x7f9ba65c8800 (LWP 227891))]

Thread 9 (Thread 0x7f9b9f5ef700 (LWP 232642)):
#0  0x00007f9bad382bf6 in __ppoll (fds=fds@entry=0x7f9b9400ce08, nfds=nfds@entry=1, timeout=<optimized out>, timeout@entry=0x0, sigmask=sigmask@entry=0x0) at ../sysdeps/unix/sysv/linux/ppoll.c:44
#1  0x00007f9babd7e4a9 in ppoll (__ss=<optimized out>, __timeout=<optimized out>, __nfds=<optimized out>, __fds=<optimized out>) at /usr/include/x86_64-linux-gnu/bits/poll2.h:77
#2  qt_ppoll (timeout_ts=0x0, nfds=1, fds=0x7f9b9400ce08) at kernel/qcore_unix.cpp:132
#3  qt_ppoll (timeout_ts=0x0, nfds=1, fds=0x7f9b9400ce08) at kernel/qcore_unix.cpp:129
#4  qt_safe_poll (fds=0x7f9b9400ce08, nfds=1, timeout_ts=timeout_ts@entry=0x0) at kernel/qcore_unix.cpp:153
#5  0x00007f9babd7fa14 in QEventDispatcherUNIX::processEvents (this=<optimized out>, flags=...) at ../../include/QtCore/../../src/corelib/tools/qarraydata.h:211
#6  0x00007f9babd294db in QEventLoop::exec (this=this@entry=0x7f9b9f5eed80, flags=..., flags@entry=...) at ../../include/QtCore/../../src/corelib/global/qflags.h:140
#7  0x00007f9babb61785 in QThread::exec (this=<optimized out>) at ../../include/QtCore/../../src/corelib/global/qflags.h:120
#8  0x00007f9baa8931a9 in ?? () from /lib/x86_64-linux-gnu/libQt5Qml.so.5
#9  0x00007f9babb629d2 in QThreadPrivate::start (arg=0x561a2662b010) at thread/qthread_unix.cpp:361
#10 0x00007f9bab120609 in start_thread (arg=<optimized out>) at pthread_create.c:477
#11 0x00007f9bad38f293 in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 8 (Thread 0x7f9b03fbb700 (LWP 228076)):
#0  futex_wait_cancelable (private=<optimized out>, expected=0, futex_word=0x561a25af5e38) at ../sysdeps/nptl/futex-internal.h:183
#1  __pthread_cond_wait_common (abstime=0x0, clockid=0, mutex=0x561a25af5de8, cond=0x561a25af5e10) at pthread_cond_wait.c:508
#2  __pthread_cond_wait (cond=0x561a25af5e10, mutex=0x561a25af5de8) at pthread_cond_wait.c:647
#3  0x00007f9b0ad5eb5b in ?? () from /usr/lib/x86_64-linux-gnu/dri/iris_dri.so
#4  0x00007f9b0ad5e75b in ?? () from /usr/lib/x86_64-linux-gnu/dri/iris_dri.so
#5  0x00007f9bab120609 in start_thread (arg=<optimized out>) at pthread_create.c:477
#6  0x00007f9bad38f293 in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 7 (Thread 0x7f9b047bc700 (LWP 228075)):
#0  futex_wait_cancelable (private=<optimized out>, expected=0, futex_word=0x561a25af5e38) at ../sysdeps/nptl/futex-internal.h:183
#1  __pthread_cond_wait_common (abstime=0x0, clockid=0, mutex=0x561a25af5de8, cond=0x561a25af5e10) at pthread_cond_wait.c:508
#2  __pthread_cond_wait (cond=0x561a25af5e10, mutex=0x561a25af5de8) at pthread_cond_wait.c:647
#3  0x00007f9b0ad5eb5b in ?? () from /usr/lib/x86_64-linux-gnu/dri/iris_dri.so
#4  0x00007f9b0ad5e75b in ?? () from /usr/lib/x86_64-linux-gnu/dri/iris_dri.so
#5  0x00007f9bab120609 in start_thread (arg=<optimized out>) at pthread_create.c:477
#6  0x00007f9bad38f293 in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 6 (Thread 0x7f9b04fbd700 (LWP 228074)):
#0  futex_wait_cancelable (private=<optimized out>, expected=0, futex_word=0x561a25af5e38) at ../sysdeps/nptl/futex-internal.h:183
#1  __pthread_cond_wait_common (abstime=0x0, clockid=0, mutex=0x561a25af5de8, cond=0x561a25af5e10) at pthread_cond_wait.c:508
#2  __pthread_cond_wait (cond=0x561a25af5e10, mutex=0x561a25af5de8) at pthread_cond_wait.c:647
#3  0x00007f9b0ad5eb5b in ?? () from /usr/lib/x86_64-linux-gnu/dri/iris_dri.so
#4  0x00007f9b0ad5e75b in ?? () from /usr/lib/x86_64-linux-gnu/dri/iris_dri.so
#5  0x00007f9bab120609 in start_thread (arg=<optimized out>) at pthread_create.c:477
#6  0x00007f9bad38f293 in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 5 (Thread 0x7f9b057be700 (LWP 228073)):
#0  futex_wait_cancelable (private=<optimized out>, expected=0, futex_word=0x561a25af5e38) at ../sysdeps/nptl/futex-internal.h:183
#1  __pthread_cond_wait_common (abstime=0x0, clockid=0, mutex=0x561a25af5de8, cond=0x561a25af5e10) at pthread_cond_wait.c:508
#2  __pthread_cond_wait (cond=0x561a25af5e10, mutex=0x561a25af5de8) at pthread_cond_wait.c:647
#3  0x00007f9b0ad5eb5b in ?? () from /usr/lib/x86_64-linux-gnu/dri/iris_dri.so
#4  0x00007f9b0ad5e75b in ?? () from /usr/lib/x86_64-linux-gnu/dri/iris_dri.so
#5  0x00007f9bab120609 in start_thread (arg=<optimized out>) at pthread_create.c:477
#6  0x00007f9bad38f293 in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 4 (Thread 0x7f9b9dae3700 (LWP 228071)):
#0  futex_wait_cancelable (private=<optimized out>, expected=0, futex_word=0x7f9bab76bfb8) at ../sysdeps/nptl/futex-internal.h:183
#1  __pthread_cond_wait_common (abstime=0x0, clockid=0, mutex=0x7f9bab76bf68, cond=0x7f9bab76bf90) at pthread_cond_wait.c:508
#2  __pthread_cond_wait (cond=0x7f9bab76bf90, mutex=0x7f9bab76bf68) at pthread_cond_wait.c:647
#3  0x00007f9bab66e5fa in ?? () from /lib/x86_64-linux-gnu/libQt5Script.so.5
#4  0x00007f9bab66e61f in ?? () from /lib/x86_64-linux-gnu/libQt5Script.so.5
#5  0x00007f9bab120609 in start_thread (arg=<optimized out>) at pthread_create.c:477
#6  0x00007f9bad38f293 in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 3 (Thread 0x7f9b9ed2c700 (LWP 228050)):
#0  0x00007f9bad382bf6 in __ppoll (fds=fds@entry=0x7f9b8c000d68, nfds=nfds@entry=1, timeout=<optimized out>, timeout@entry=0x0, sigmask=sigmask@entry=0x0) at ../sysdeps/unix/sysv/linux/ppoll.c:44
#1  0x00007f9babd7e4a9 in ppoll (__ss=<optimized out>, __timeout=<optimized out>, __nfds=<optimized out>, __fds=<optimized out>) at /usr/include/x86_64-linux-gnu/bits/poll2.h:77
#2  qt_ppoll (timeout_ts=0x0, nfds=1, fds=0x7f9b8c000d68) at kernel/qcore_unix.cpp:132
#3  qt_ppoll (timeout_ts=0x0, nfds=1, fds=0x7f9b8c000d68) at kernel/qcore_unix.cpp:129
#4  qt_safe_poll (fds=0x7f9b8c000d68, nfds=1, timeout_ts=timeout_ts@entry=0x0) at kernel/qcore_unix.cpp:153
#5  0x00007f9babd7fa14 in QEventDispatcherUNIX::processEvents (this=<optimized out>, flags=...) at ../../include/QtCore/../../src/corelib/tools/qarraydata.h:211
#6  0x00007f9babd294db in QEventLoop::exec (this=this@entry=0x7f9b9ed2bd80, flags=..., flags@entry=...) at ../../include/QtCore/../../src/corelib/global/qflags.h:140
#7  0x00007f9babb61785 in QThread::exec (this=<optimized out>) at ../../include/QtCore/../../src/corelib/global/qflags.h:120
#8  0x00007f9baa8931a9 in ?? () from /lib/x86_64-linux-gnu/libQt5Qml.so.5
#9  0x00007f9babb629d2 in QThreadPrivate::start (arg=0x561a25b88e60) at thread/qthread_unix.cpp:361
#10 0x00007f9bab120609 in start_thread (arg=<optimized out>) at pthread_create.c:477
#11 0x00007f9bad38f293 in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 2 (Thread 0x7f9ba4c17700 (LWP 227947)):
#0  0x00007f9bad382bf6 in __ppoll (fds=fds@entry=0x7f9b9800b7c8, nfds=nfds@entry=1, timeout=<optimized out>, timeout@entry=0x0, sigmask=sigmask@entry=0x0) at ../sysdeps/unix/sysv/linux/ppoll.c:44
#1  0x00007f9babd7e4a9 in ppoll (__ss=<optimized out>, __timeout=<optimized out>, __nfds=<optimized out>, __fds=<optimized out>) at /usr/include/x86_64-linux-gnu/bits/poll2.h:77
#2  qt_ppoll (timeout_ts=0x0, nfds=1, fds=0x7f9b9800b7c8) at kernel/qcore_unix.cpp:132
#3  qt_ppoll (timeout_ts=0x0, nfds=1, fds=0x7f9b9800b7c8) at kernel/qcore_unix.cpp:129
#4  qt_safe_poll (fds=0x7f9b9800b7c8, nfds=1, timeout_ts=timeout_ts@entry=0x0) at kernel/qcore_unix.cpp:153
#5  0x00007f9babd7fa14 in QEventDispatcherUNIX::processEvents (this=<optimized out>, flags=...) at ../../include/QtCore/../../src/corelib/tools/qarraydata.h:211
#6  0x00007f9babd294db in QEventLoop::exec (this=this@entry=0x7f9ba4c16d70, flags=..., flags@entry=...) at ../../include/QtCore/../../src/corelib/global/qflags.h:140
#7  0x00007f9babb61785 in QThread::exec (this=this@entry=0x7f9bace16d80 <(anonymous namespace)::Q_QGS__q_manager::innerFunction()::holder>) at ../../include/QtCore/../../src/corelib/global/qflags.h:120
#8  0x00007f9bacd93efa in QDBusConnectionManager::run (this=0x7f9bace16d80 <(anonymous namespace)::Q_QGS__q_manager::innerFunction()::holder>) at qdbusconnection.cpp:178
#9  0x00007f9babb629d2 in QThreadPrivate::start (arg=0x7f9bace16d80 <(anonymous namespace)::Q_QGS__q_manager::innerFunction()::holder>) at thread/qthread_unix.cpp:361
#10 0x00007f9bab120609 in start_thread (arg=<optimized out>) at pthread_create.c:477
#11 0x00007f9bad38f293 in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 1 (Thread 0x7f9ba65c8800 (LWP 227891)):
[KCrash Handler]
#6  0x0000561a265951a0 in ?? ()
#7  0x00007f9bad063e66 in KWin::Workspace::workspaceEvent (this=0x561a259d28f0, e=0x7f9ba000fd60) at ./x11eventfilter.h:51
#8  0x00007f9babd27d8f in QAbstractEventDispatcher::filterNativeEvent (this=<optimized out>, eventType=..., message=message@entry=0x7f9ba000fd60, result=result@entry=0x7ffec19c6698) at kernel/qabstracteventdispatcher.cpp:484
#9  0x00007f9ba5c747b5 in QXcbConnection::handleXcbEvent (this=this@entry=0x561a2590b920, event=event@entry=0x7f9ba000fd60) at qxcbnativeinterface.h:101
#10 0x00007f9ba5c7578a in QXcbConnection::processXcbEvents (this=0x561a2590b920, flags=...) at qxcbconnection.cpp:1027
#11 0x00007f9ba5ca06f0 in QXcbUnixEventDispatcher::processEvents (this=0x561a2595ef00, flags=...) at qxcbeventdispatcher.cpp:61
#12 0x00007f9babd294db in QEventLoop::exec (this=this@entry=0x7ffec19c6820, flags=..., flags@entry=...) at ../../include/QtCore/../../src/corelib/global/qflags.h:140
#13 0x00007f9babd31246 in QCoreApplication::exec () at ../../include/QtCore/../../src/corelib/global/qflags.h:120
#14 0x00007f9bad4689ef in kdemain (argc=<optimized out>, argv=0x7ffec19c6ab8) at ./main_x11.cpp:483
#15 0x00007f9bad2940b3 in __libc_start_main (main=0x561a23ef0060 <main>, argc=1, argv=0x7ffec19c6ab8, init=<optimized out>, fini=<optimized out>, rtld_fini=<optimized out>, stack_end=0x7ffec19c6aa8) at ../csu/libc-start.c:308
#16 0x0000561a23ef009e in _start ()
[Inferior 1 (process 227891) detached]

Possible duplicates by query: bug 437352, bug 435174, bug 434865, bug 434372, bug 434368.

Reported using DrKonqi