Application: kwin_x11 (5.12.6)

Qt Version: 5.9.5
Frameworks Version: 5.44.0
Operating System: Linux 4.15.0-39-generic x86_64
Distribution: Ubuntu 18.04.1 LTS

-- Information about the crash:
- What I was doing when the application crashed:
Switching application focus using "Present Windows > Window Class" (im assuming) via Latte Dock
I was on virtual desktop 1 which would have switched to virtual desktop 2 after using the mouse to click the window I wanted.

- Unusual behavior I noticed:
Desktop crashed (but recovered on its own) and some windows shifted upwards vertically but not out of bounds.
Overall everything seemed to recover gracefully

- Custom settings of the application:
Application I was switching to has "force desktop" enabled via "application settings/window rules"

The crash can be reproduced sometimes.

-- 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 0x7f43f6a14040 (LWP 1480))]

Thread 29 (Thread 0x7f42ebfff700 (LWP 6450)):
#0  0x00007f43f5c359f3 in futex_wait_cancelable (private=<optimized out>, expected=0, futex_word=0x55f6fe8a8394) at ../sysdeps/unix/sysv/linux/futex-internal.h:88
#1  0x00007f43f5c359f3 in __pthread_cond_wait_common (abstime=0x0, mutex=0x55f6fe8a8340, cond=0x55f6fe8a8368) at pthread_cond_wait.c:502
#2  0x00007f43f5c359f3 in __pthread_cond_wait (cond=0x55f6fe8a8368, mutex=0x55f6fe8a8340) at pthread_cond_wait.c:655
#3  0x00007f43bf46d46b in  () at /usr/lib/x86_64-linux-gnu/dri/radeonsi_dri.so
#4  0x00007f43bf46d197 in  () at /usr/lib/x86_64-linux-gnu/dri/radeonsi_dri.so
#5  0x00007f43f5c2f6db in start_thread (arg=0x7f42ebfff700) at pthread_create.c:463
#6  0x00007f43f616c88f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 28 (Thread 0x7f42cd3aa700 (LWP 5740)):
#0  0x00007f43f5c359f3 in futex_wait_cancelable (private=<optimized out>, expected=0, futex_word=0x55f6fcc78390) at ../sysdeps/unix/sysv/linux/futex-internal.h:88
#1  0x00007f43f5c359f3 in __pthread_cond_wait_common (abstime=0x0, mutex=0x55f6fcc78340, cond=0x55f6fcc78368) at pthread_cond_wait.c:502
#2  0x00007f43f5c359f3 in __pthread_cond_wait (cond=0x55f6fcc78368, mutex=0x55f6fcc78340) at pthread_cond_wait.c:655
#3  0x00007f43bf46d46b in  () at /usr/lib/x86_64-linux-gnu/dri/radeonsi_dri.so
#4  0x00007f43bf46d197 in  () at /usr/lib/x86_64-linux-gnu/dri/radeonsi_dri.so
#5  0x00007f43f5c2f6db in start_thread (arg=0x7f42cd3aa700) at pthread_create.c:463
#6  0x00007f43f616c88f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 27 (Thread 0x7f42cdbab700 (LWP 5738)):
#0  0x00007f43f5c359f3 in futex_wait_cancelable (private=<optimized out>, expected=0, futex_word=0x55f6fdcef070) at ../sysdeps/unix/sysv/linux/futex-internal.h:88
#1  0x00007f43f5c359f3 in __pthread_cond_wait_common (abstime=0x0, mutex=0x55f6fdcef020, cond=0x55f6fdcef048) at pthread_cond_wait.c:502
#2  0x00007f43f5c359f3 in __pthread_cond_wait (cond=0x55f6fdcef048, mutex=0x55f6fdcef020) at pthread_cond_wait.c:655
#3  0x00007f43bf46d46b in  () at /usr/lib/x86_64-linux-gnu/dri/radeonsi_dri.so
#4  0x00007f43bf46d197 in  () at /usr/lib/x86_64-linux-gnu/dri/radeonsi_dri.so
#5  0x00007f43f5c2f6db in start_thread (arg=0x7f42cdbab700) at pthread_create.c:463
#6  0x00007f43f616c88f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 26 (Thread 0x7f42ea7fd700 (LWP 5732)):
#0  0x00007f43f5c359f3 in futex_wait_cancelable (private=<optimized out>, expected=0, futex_word=0x55f6fe679490) at ../sysdeps/unix/sysv/linux/futex-internal.h:88
#1  0x00007f43f5c359f3 in __pthread_cond_wait_common (abstime=0x0, mutex=0x55f6fe679440, cond=0x55f6fe679468) at pthread_cond_wait.c:502
#2  0x00007f43f5c359f3 in __pthread_cond_wait (cond=0x55f6fe679468, mutex=0x55f6fe679440) at pthread_cond_wait.c:655
#3  0x00007f43bf46d46b in  () at /usr/lib/x86_64-linux-gnu/dri/radeonsi_dri.so
#4  0x00007f43bf46d197 in  () at /usr/lib/x86_64-linux-gnu/dri/radeonsi_dri.so
#5  0x00007f43f5c2f6db in start_thread (arg=0x7f42ea7fd700) at pthread_create.c:463
#6  0x00007f43f616c88f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 25 (Thread 0x7f42eaffe700 (LWP 5640)):
#0  0x00007f43f5c359f3 in futex_wait_cancelable (private=<optimized out>, expected=0, futex_word=0x55f6fe89d840) at ../sysdeps/unix/sysv/linux/futex-internal.h:88
#1  0x00007f43f5c359f3 in __pthread_cond_wait_common (abstime=0x0, mutex=0x55f6fe89d7f0, cond=0x55f6fe89d818) at pthread_cond_wait.c:502
#2  0x00007f43f5c359f3 in __pthread_cond_wait (cond=0x55f6fe89d818, mutex=0x55f6fe89d7f0) at pthread_cond_wait.c:655
#3  0x00007f43bf46d46b in  () at /usr/lib/x86_64-linux-gnu/dri/radeonsi_dri.so
#4  0x00007f43bf46d197 in  () at /usr/lib/x86_64-linux-gnu/dri/radeonsi_dri.so
#5  0x00007f43f5c2f6db in start_thread (arg=0x7f42eaffe700) at pthread_create.c:463
#6  0x00007f43f616c88f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 24 (Thread 0x7f42daac7700 (LWP 5453)):
#0  0x00007f43f5c359f3 in futex_wait_cancelable (private=<optimized out>, expected=0, futex_word=0x55f6fdd4b8d0) at ../sysdeps/unix/sysv/linux/futex-internal.h:88
#1  0x00007f43f5c359f3 in __pthread_cond_wait_common (abstime=0x0, mutex=0x55f6fdd4b880, cond=0x55f6fdd4b8a8) at pthread_cond_wait.c:502
#2  0x00007f43f5c359f3 in __pthread_cond_wait (cond=0x55f6fdd4b8a8, mutex=0x55f6fdd4b880) at pthread_cond_wait.c:655
#3  0x00007f43bf46d46b in  () at /usr/lib/x86_64-linux-gnu/dri/radeonsi_dri.so
#4  0x00007f43bf46d197 in  () at /usr/lib/x86_64-linux-gnu/dri/radeonsi_dri.so
#5  0x00007f43f5c2f6db in start_thread (arg=0x7f42daac7700) at pthread_create.c:463
#6  0x00007f43f616c88f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 23 (Thread 0x7f42fd005700 (LWP 4926)):
#0  0x00007f43f5c359f3 in futex_wait_cancelable (private=<optimized out>, expected=0, futex_word=0x55f6fcbbabe0) at ../sysdeps/unix/sysv/linux/futex-internal.h:88
#1  0x00007f43f5c359f3 in __pthread_cond_wait_common (abstime=0x0, mutex=0x55f6fcbbab90, cond=0x55f6fcbbabb8) at pthread_cond_wait.c:502
#2  0x00007f43f5c359f3 in __pthread_cond_wait (cond=0x55f6fcbbabb8, mutex=0x55f6fcbbab90) at pthread_cond_wait.c:655
#3  0x00007f43bf46d46b in  () at /usr/lib/x86_64-linux-gnu/dri/radeonsi_dri.so
#4  0x00007f43bf46d197 in  () at /usr/lib/x86_64-linux-gnu/dri/radeonsi_dri.so
#5  0x00007f43f5c2f6db in start_thread (arg=0x7f42fd005700) at pthread_create.c:463
#6  0x00007f43f616c88f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 22 (Thread 0x7f42e9503700 (LWP 32282)):
#0  0x00007f43f5c359f3 in futex_wait_cancelable (private=<optimized out>, expected=0, futex_word=0x55f6fdedc994) at ../sysdeps/unix/sysv/linux/futex-internal.h:88
#1  0x00007f43f5c359f3 in __pthread_cond_wait_common (abstime=0x0, mutex=0x55f6fdedc940, cond=0x55f6fdedc968) at pthread_cond_wait.c:502
#2  0x00007f43f5c359f3 in __pthread_cond_wait (cond=0x55f6fdedc968, mutex=0x55f6fdedc940) at pthread_cond_wait.c:655
#3  0x00007f43bf46d46b in  () at /usr/lib/x86_64-linux-gnu/dri/radeonsi_dri.so
#4  0x00007f43bf46d197 in  () at /usr/lib/x86_64-linux-gnu/dri/radeonsi_dri.so
#5  0x00007f43f5c2f6db in start_thread (arg=0x7f42e9503700) at pthread_create.c:463
#6  0x00007f43f616c88f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 21 (Thread 0x7f42e8d02700 (LWP 29028)):
#0  0x00007f43f5c359f3 in futex_wait_cancelable (private=<optimized out>, expected=0, futex_word=0x55f6fe6da5d0) at ../sysdeps/unix/sysv/linux/futex-internal.h:88
#1  0x00007f43f5c359f3 in __pthread_cond_wait_common (abstime=0x0, mutex=0x55f6fe6da580, cond=0x55f6fe6da5a8) at pthread_cond_wait.c:502
#2  0x00007f43f5c359f3 in __pthread_cond_wait (cond=0x55f6fe6da5a8, mutex=0x55f6fe6da580) at pthread_cond_wait.c:655
#3  0x00007f43bf46d46b in  () at /usr/lib/x86_64-linux-gnu/dri/radeonsi_dri.so
#4  0x00007f43bf46d197 in  () at /usr/lib/x86_64-linux-gnu/dri/radeonsi_dri.so
#5  0x00007f43f5c2f6db in start_thread (arg=0x7f42e8d02700) at pthread_create.c:463
#6  0x00007f43f616c88f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 20 (Thread 0x7f42fffff700 (LWP 4154)):
#0  0x00007f43f615fcf6 in __GI_ppoll (fds=0x7f42ec046558, nfds=1, timeout=<optimized out>, sigmask=0x0) at ../sysdeps/unix/sysv/linux/ppoll.c:39
#1  0x00007f43f313e5c1 in qt_safe_poll(pollfd*, unsigned long, timespec const*) () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#2  0x00007f43f313fcde in QEventDispatcherUNIX::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#3  0x00007f43f30e79ea in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#4  0x00007f43f2f0622a in QThread::exec() () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#5  0x00007f43edaae6f5 in  () at /usr/lib/x86_64-linux-gnu/libQt5Qml.so.5
#6  0x00007f43f2f0b16d in  () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#7  0x00007f43f5c2f6db in start_thread (arg=0x7f42fffff700) at pthread_create.c:463
#8  0x00007f43f616c88f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 19 (Thread 0x7f42feffd700 (LWP 2913)):
#0  0x00007f43f5c359f3 in futex_wait_cancelable (private=<optimized out>, expected=0, futex_word=0x55f6fd1a54f4) at ../sysdeps/unix/sysv/linux/futex-internal.h:88
#1  0x00007f43f5c359f3 in __pthread_cond_wait_common (abstime=0x0, mutex=0x55f6fd1a54a0, cond=0x55f6fd1a54c8) at pthread_cond_wait.c:502
#2  0x00007f43f5c359f3 in __pthread_cond_wait (cond=0x55f6fd1a54c8, mutex=0x55f6fd1a54a0) at pthread_cond_wait.c:655
#3  0x00007f43bf46d46b in  () at /usr/lib/x86_64-linux-gnu/dri/radeonsi_dri.so
#4  0x00007f43bf46d197 in  () at /usr/lib/x86_64-linux-gnu/dri/radeonsi_dri.so
#5  0x00007f43f5c2f6db in start_thread (arg=0x7f42feffd700) at pthread_create.c:463
#6  0x00007f43f616c88f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 18 (Thread 0x7f42ff7fe700 (LWP 2682)):
#0  0x00007f43f5c359f3 in futex_wait_cancelable (private=<optimized out>, expected=0, futex_word=0x55f6fcf423f4) at ../sysdeps/unix/sysv/linux/futex-internal.h:88
#1  0x00007f43f5c359f3 in __pthread_cond_wait_common (abstime=0x0, mutex=0x55f6fcf423a0, cond=0x55f6fcf423c8) at pthread_cond_wait.c:502
#2  0x00007f43f5c359f3 in __pthread_cond_wait (cond=0x55f6fcf423c8, mutex=0x55f6fcf423a0) at pthread_cond_wait.c:655
#3  0x00007f43bf46d46b in  () at /usr/lib/x86_64-linux-gnu/dri/radeonsi_dri.so
#4  0x00007f43bf46d197 in  () at /usr/lib/x86_64-linux-gnu/dri/radeonsi_dri.so
#5  0x00007f43f5c2f6db in start_thread (arg=0x7f42ff7fe700) at pthread_create.c:463
#6  0x00007f43f616c88f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 17 (Thread 0x7f4306ca0700 (LWP 2364)):
#0  0x00007f43f5c359f3 in futex_wait_cancelable (private=<optimized out>, expected=0, futex_word=0x55f6fc9feb44) at ../sysdeps/unix/sysv/linux/futex-internal.h:88
#1  0x00007f43f5c359f3 in __pthread_cond_wait_common (abstime=0x0, mutex=0x55f6fc9feaf0, cond=0x55f6fc9feb18) at pthread_cond_wait.c:502
#2  0x00007f43f5c359f3 in __pthread_cond_wait (cond=0x55f6fc9feb18, mutex=0x55f6fc9feaf0) at pthread_cond_wait.c:655
#3  0x00007f43bf46d46b in  () at /usr/lib/x86_64-linux-gnu/dri/radeonsi_dri.so
#4  0x00007f43bf46d197 in  () at /usr/lib/x86_64-linux-gnu/dri/radeonsi_dri.so
#5  0x00007f43f5c2f6db in start_thread (arg=0x7f4306ca0700) at pthread_create.c:463
#6  0x00007f43f616c88f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 16 (Thread 0x7f4307840700 (LWP 2336)):
#0  0x00007f43f5c359f3 in futex_wait_cancelable (private=<optimized out>, expected=0, futex_word=0x55f6fc89df24) at ../sysdeps/unix/sysv/linux/futex-internal.h:88
#1  0x00007f43f5c359f3 in __pthread_cond_wait_common (abstime=0x0, mutex=0x55f6fc89ded0, cond=0x55f6fc89def8) at pthread_cond_wait.c:502
#2  0x00007f43f5c359f3 in __pthread_cond_wait (cond=0x55f6fc89def8, mutex=0x55f6fc89ded0) at pthread_cond_wait.c:655
#3  0x00007f43bf46d46b in  () at /usr/lib/x86_64-linux-gnu/dri/radeonsi_dri.so
#4  0x00007f43bf46d197 in  () at /usr/lib/x86_64-linux-gnu/dri/radeonsi_dri.so
#5  0x00007f43f5c2f6db in start_thread (arg=0x7f4307840700) at pthread_create.c:463
#6  0x00007f43f616c88f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 15 (Thread 0x7f430877e700 (LWP 2075)):
#0  0x00007f43f5c359f3 in futex_wait_cancelable (private=<optimized out>, expected=0, futex_word=0x55f6fc628320) at ../sysdeps/unix/sysv/linux/futex-internal.h:88
#1  0x00007f43f5c359f3 in __pthread_cond_wait_common (abstime=0x0, mutex=0x55f6fc6282d0, cond=0x55f6fc6282f8) at pthread_cond_wait.c:502
#2  0x00007f43f5c359f3 in __pthread_cond_wait (cond=0x55f6fc6282f8, mutex=0x55f6fc6282d0) at pthread_cond_wait.c:655
#3  0x00007f43bf46d46b in  () at /usr/lib/x86_64-linux-gnu/dri/radeonsi_dri.so
#4  0x00007f43bf46d197 in  () at /usr/lib/x86_64-linux-gnu/dri/radeonsi_dri.so
#5  0x00007f43f5c2f6db in start_thread (arg=0x7f430877e700) at pthread_create.c:463
#6  0x00007f43f616c88f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 14 (Thread 0x7f43c67c9700 (LWP 2060)):
#0  0x00007f43f615fcf6 in __GI_ppoll (fds=0x7f43c0000d68, nfds=1, timeout=<optimized out>, sigmask=0x0) at ../sysdeps/unix/sysv/linux/ppoll.c:39
#1  0x00007f43f313e5c1 in qt_safe_poll(pollfd*, unsigned long, timespec const*) () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#2  0x00007f43f313fcde in QEventDispatcherUNIX::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#3  0x00007f43f30e79ea in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#4  0x00007f43f2f0622a in QThread::exec() () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#5  0x00007f43edaae6f5 in  () at /usr/lib/x86_64-linux-gnu/libQt5Qml.so.5
#6  0x00007f43f2f0b16d in  () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#7  0x00007f43f5c2f6db in start_thread (arg=0x7f43c67c9700) at pthread_create.c:463
#8  0x00007f43f616c88f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 13 (Thread 0x7f439a7fc700 (LWP 1630)):
#0  0x00007f43f5c359f3 in futex_wait_cancelable (private=<optimized out>, expected=0, futex_word=0x7f43f2340fb8) at ../sysdeps/unix/sysv/linux/futex-internal.h:88
#1  0x00007f43f5c359f3 in __pthread_cond_wait_common (abstime=0x0, mutex=0x7f43f2340f68, cond=0x7f43f2340f90) at pthread_cond_wait.c:502
#2  0x00007f43f5c359f3 in __pthread_cond_wait (cond=0x7f43f2340f90, mutex=0x7f43f2340f68) at pthread_cond_wait.c:655
#3  0x00007f43f204a5f4 in  () at /usr/lib/x86_64-linux-gnu/libQt5Script.so.5
#4  0x00007f43f204a639 in  () at /usr/lib/x86_64-linux-gnu/libQt5Script.so.5
#5  0x00007f43f5c2f6db in start_thread (arg=0x7f439a7fc700) at pthread_create.c:463
#6  0x00007f43f616c88f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 12 (Thread 0x7f439b7fe700 (LWP 1628)):
#0  0x00007f43f5c359f3 in futex_wait_cancelable (private=<optimized out>, expected=0, futex_word=0x55f6fc1fa074) at ../sysdeps/unix/sysv/linux/futex-internal.h:88
#1  0x00007f43f5c359f3 in __pthread_cond_wait_common (abstime=0x0, mutex=0x55f6fc1fa020, cond=0x55f6fc1fa048) at pthread_cond_wait.c:502
#2  0x00007f43f5c359f3 in __pthread_cond_wait (cond=0x55f6fc1fa048, mutex=0x55f6fc1fa020) at pthread_cond_wait.c:655
#3  0x00007f43bf46d46b in  () at /usr/lib/x86_64-linux-gnu/dri/radeonsi_dri.so
#4  0x00007f43bf46d197 in  () at /usr/lib/x86_64-linux-gnu/dri/radeonsi_dri.so
#5  0x00007f43f5c2f6db in start_thread (arg=0x7f439b7fe700) at pthread_create.c:463
#6  0x00007f43f616c88f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 11 (Thread 0x7f439bfff700 (LWP 1625)):
#0  0x00007f43f5c359f3 in futex_wait_cancelable (private=<optimized out>, expected=0, futex_word=0x55f6fc12c54c) at ../sysdeps/unix/sysv/linux/futex-internal.h:88
#1  0x00007f43f5c359f3 in __pthread_cond_wait_common (abstime=0x0, mutex=0x55f6fc12c4f8, cond=0x55f6fc12c520) at pthread_cond_wait.c:502
#2  0x00007f43f5c359f3 in __pthread_cond_wait (cond=0x55f6fc12c520, mutex=0x55f6fc12c4f8) at pthread_cond_wait.c:655
#3  0x00007f43bf46d46b in  () at /usr/lib/x86_64-linux-gnu/dri/radeonsi_dri.so
#4  0x00007f43bf46d197 in  () at /usr/lib/x86_64-linux-gnu/dri/radeonsi_dri.so
#5  0x00007f43f5c2f6db in start_thread (arg=0x7f439bfff700) at pthread_create.c:463
#6  0x00007f43f616c88f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 10 (Thread 0x7f43b8b20700 (LWP 1624)):
#0  0x00007f43f5c359f3 in futex_wait_cancelable (private=<optimized out>, expected=0, futex_word=0x55f6fc12c54c) at ../sysdeps/unix/sysv/linux/futex-internal.h:88
#1  0x00007f43f5c359f3 in __pthread_cond_wait_common (abstime=0x0, mutex=0x55f6fc12c4f8, cond=0x55f6fc12c520) at pthread_cond_wait.c:502
#2  0x00007f43f5c359f3 in __pthread_cond_wait (cond=0x55f6fc12c520, mutex=0x55f6fc12c4f8) at pthread_cond_wait.c:655
#3  0x00007f43bf46d46b in  () at /usr/lib/x86_64-linux-gnu/dri/radeonsi_dri.so
#4  0x00007f43bf46d197 in  () at /usr/lib/x86_64-linux-gnu/dri/radeonsi_dri.so
#5  0x00007f43f5c2f6db in start_thread (arg=0x7f43b8b20700) at pthread_create.c:463
#6  0x00007f43f616c88f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 9 (Thread 0x7f43b9321700 (LWP 1623)):
#0  0x00007f43f5c359f3 in futex_wait_cancelable (private=<optimized out>, expected=0, futex_word=0x55f6fc12c438) at ../sysdeps/unix/sysv/linux/futex-internal.h:88
#1  0x00007f43f5c359f3 in __pthread_cond_wait_common (abstime=0x0, mutex=0x55f6fc12c3e8, cond=0x55f6fc12c410) at pthread_cond_wait.c:502
#2  0x00007f43f5c359f3 in __pthread_cond_wait (cond=0x55f6fc12c410, mutex=0x55f6fc12c3e8) at pthread_cond_wait.c:655
#3  0x00007f43bf46d46b in  () at /usr/lib/x86_64-linux-gnu/dri/radeonsi_dri.so
#4  0x00007f43bf46d197 in  () at /usr/lib/x86_64-linux-gnu/dri/radeonsi_dri.so
#5  0x00007f43f5c2f6db in start_thread (arg=0x7f43b9321700) at pthread_create.c:463
#6  0x00007f43f616c88f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 8 (Thread 0x7f43b9b22700 (LWP 1622)):
#0  0x00007f43f5c359f3 in futex_wait_cancelable (private=<optimized out>, expected=0, futex_word=0x55f6fc12c43c) at ../sysdeps/unix/sysv/linux/futex-internal.h:88
#1  0x00007f43f5c359f3 in __pthread_cond_wait_common (abstime=0x0, mutex=0x55f6fc12c3e8, cond=0x55f6fc12c410) at pthread_cond_wait.c:502
#2  0x00007f43f5c359f3 in __pthread_cond_wait (cond=0x55f6fc12c410, mutex=0x55f6fc12c3e8) at pthread_cond_wait.c:655
#3  0x00007f43bf46d46b in  () at /usr/lib/x86_64-linux-gnu/dri/radeonsi_dri.so
#4  0x00007f43bf46d197 in  () at /usr/lib/x86_64-linux-gnu/dri/radeonsi_dri.so
#5  0x00007f43f5c2f6db in start_thread (arg=0x7f43b9b22700) at pthread_create.c:463
#6  0x00007f43f616c88f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 7 (Thread 0x7f43ba323700 (LWP 1621)):
#0  0x00007f43f5c359f3 in futex_wait_cancelable (private=<optimized out>, expected=0, futex_word=0x55f6fc12c43c) at ../sysdeps/unix/sysv/linux/futex-internal.h:88
#1  0x00007f43f5c359f3 in __pthread_cond_wait_common (abstime=0x0, mutex=0x55f6fc12c3e8, cond=0x55f6fc12c410) at pthread_cond_wait.c:502
#2  0x00007f43f5c359f3 in __pthread_cond_wait (cond=0x55f6fc12c410, mutex=0x55f6fc12c3e8) at pthread_cond_wait.c:655
#3  0x00007f43bf46d46b in  () at /usr/lib/x86_64-linux-gnu/dri/radeonsi_dri.so
#4  0x00007f43bf46d197 in  () at /usr/lib/x86_64-linux-gnu/dri/radeonsi_dri.so
#5  0x00007f43f5c2f6db in start_thread (arg=0x7f43ba323700) at pthread_create.c:463
#6  0x00007f43f616c88f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 6 (Thread 0x7f43bab24700 (LWP 1620)):
#0  0x00007f43f5c359f3 in futex_wait_cancelable (private=<optimized out>, expected=0, futex_word=0x55f6fbf45488) at ../sysdeps/unix/sysv/linux/futex-internal.h:88
#1  0x00007f43f5c359f3 in __pthread_cond_wait_common (abstime=0x0, mutex=0x55f6fbf45438, cond=0x55f6fbf45460) at pthread_cond_wait.c:502
#2  0x00007f43f5c359f3 in __pthread_cond_wait (cond=0x55f6fbf45460, mutex=0x55f6fbf45438) at pthread_cond_wait.c:655
#3  0x00007f43bf46d46b in  () at /usr/lib/x86_64-linux-gnu/dri/radeonsi_dri.so
#4  0x00007f43bf46d197 in  () at /usr/lib/x86_64-linux-gnu/dri/radeonsi_dri.so
#5  0x00007f43f5c2f6db in start_thread (arg=0x7f43bab24700) at pthread_create.c:463
#6  0x00007f43f616c88f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 5 (Thread 0x7f43bb466700 (LWP 1619)):
#0  0x00007f43f5c359f3 in futex_wait_cancelable (private=<optimized out>, expected=0, futex_word=0x55f6fc129330) at ../sysdeps/unix/sysv/linux/futex-internal.h:88
#1  0x00007f43f5c359f3 in __pthread_cond_wait_common (abstime=0x0, mutex=0x55f6fc1292e0, cond=0x55f6fc129308) at pthread_cond_wait.c:502
#2  0x00007f43f5c359f3 in __pthread_cond_wait (cond=0x55f6fc129308, mutex=0x55f6fc1292e0) at pthread_cond_wait.c:655
#3  0x00007f43bf46d46b in  () at /usr/lib/x86_64-linux-gnu/dri/radeonsi_dri.so
#4  0x00007f43bf46d197 in  () at /usr/lib/x86_64-linux-gnu/dri/radeonsi_dri.so
#5  0x00007f43f5c2f6db in start_thread (arg=0x7f43bb466700) at pthread_create.c:463
#6  0x00007f43f616c88f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 4 (Thread 0x7f43d487e700 (LWP 1614)):
#0  0x00007f43f615fcf6 in __GI_ppoll (fds=0x7f43cc000d28, nfds=1, timeout=<optimized out>, sigmask=0x0) at ../sysdeps/unix/sysv/linux/ppoll.c:39
#1  0x00007f43f313e5c1 in qt_safe_poll(pollfd*, unsigned long, timespec const*) () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#2  0x00007f43f313fcde in QEventDispatcherUNIX::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#3  0x00007f43f30e79ea in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#4  0x00007f43f2f0622a in QThread::exec() () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#5  0x00007f43edaae6f5 in  () at /usr/lib/x86_64-linux-gnu/libQt5Qml.so.5
#6  0x00007f43f2f0b16d in  () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#7  0x00007f43f5c2f6db in start_thread (arg=0x7f43d487e700) at pthread_create.c:463
#8  0x00007f43f616c88f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 3 (Thread 0x7f43d67bf700 (LWP 1553)):
#0  0x00007f43f615fcf6 in __GI_ppoll (fds=0x7f43d000eae8, nfds=1, timeout=<optimized out>, sigmask=0x0) at ../sysdeps/unix/sysv/linux/ppoll.c:39
#1  0x00007f43f313e5c1 in qt_safe_poll(pollfd*, unsigned long, timespec const*) () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#2  0x00007f43f313fcde in QEventDispatcherUNIX::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#3  0x00007f43f30e79ea in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#4  0x00007f43f2f0622a in QThread::exec() () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#5  0x00007f43ec987d45 in  () at /usr/lib/x86_64-linux-gnu/libQt5DBus.so.5
#6  0x00007f43f2f0b16d in  () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#7  0x00007f43f5c2f6db in start_thread (arg=0x7f43d67bf700) at pthread_create.c:463
#8  0x00007f43f616c88f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 2 (Thread 0x7f43dce80700 (LWP 1498)):
#0  0x00007f43f615fbf9 in __GI___poll (fds=0x7f43dce7fc68, nfds=1, timeout=-1) at ../sysdeps/unix/sysv/linux/poll.c:29
#1  0x00007f43f4c46747 in  () at /usr/lib/x86_64-linux-gnu/libxcb.so.1
#2  0x00007f43f4c4836a in xcb_wait_for_event () at /usr/lib/x86_64-linux-gnu/libxcb.so.1
#3  0x00007f43ddd5f2a9 in  () at /usr/lib/x86_64-linux-gnu/libQt5XcbQpa.so.5
#4  0x00007f43f2f0b16d in  () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#5  0x00007f43f5c2f6db in start_thread (arg=0x7f43dce80700) at pthread_create.c:463
#6  0x00007f43f616c88f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 1 (Thread 0x7f43f6a14040 (LWP 1480)):
[KCrash Handler]
#6  0x000055f6fcb5c590 in  ()
#7  0x00007f43f58443aa in KWin::Workspace::workspaceEvent(xcb_generic_event_t*) () at /usr/lib/x86_64-linux-gnu/libkwin.so.5
#8  0x00007f43f30e658f in QAbstractEventDispatcher::filterNativeEvent(QByteArray const&, void*, long*) () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#9  0x00007f43ddd60820 in QXcbConnection::handleXcbEvent(xcb_generic_event_t*) () at /usr/lib/x86_64-linux-gnu/libQt5XcbQpa.so.5
#10 0x00007f43ddd614ac in QXcbConnection::processXcbEvents() () at /usr/lib/x86_64-linux-gnu/libQt5XcbQpa.so.5
#11 0x00007f43f3119122 in QObject::event(QEvent*) () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#12 0x00007f43f3e6782c in QApplicationPrivate::notify_helper(QObject*, QEvent*) () at /usr/lib/x86_64-linux-gnu/libQt5Widgets.so.5
#13 0x00007f43f3e6f0f4 in QApplication::notify(QObject*, QEvent*) () at /usr/lib/x86_64-linux-gnu/libQt5Widgets.so.5
#14 0x00007f43f30e99a8 in QCoreApplication::notifyInternal2(QObject*, QEvent*) () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#15 0x00007f43f30ec11d in QCoreApplicationPrivate::sendPostedEvents(QObject*, int, QThreadData*) () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#16 0x00007f43f313faf4 in QEventDispatcherUNIX::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#17 0x00007f43dddc25cd in  () at /usr/lib/x86_64-linux-gnu/libQt5XcbQpa.so.5
#18 0x00007f43f30e79ea in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#19 0x00007f43f30f0a84 in QCoreApplication::exec() () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#20 0x00007f43f6444dbb in kdemain () at /usr/lib/x86_64-linux-gnu/libkdeinit5_kwin_x11.so
#21 0x00007f43f606cb97 in __libc_start_main (main=0x55f6fabc9730, argc=1, argv=0x7ffe2d8ac438, init=<optimized out>, fini=<optimized out>, rtld_fini=<optimized out>, stack_end=0x7ffe2d8ac428) at ../csu/libc-start.c:310
#22 0x000055f6fabc976a in _start ()

Reported using DrKonqi