Bug 355874

Application: kwin_x11 (5.3.2)

Qt Version: 5.4.1
Operating System: Linux 3.19.0-30-lowlatency x86_64
Distribution: Ubuntu 15.04

-- Information about the crash:
- What I was doing when the application crashed:
I killed existing correupted kwin_x11 with SIGHUP. Then I run  "DISPLAY=:0.0 kwin_x11 --replace" from virtual console. I witnessed there was a crash when I activated virtual console running my X server. I do not know if the crash is related to switching of virtual console, or to the fact that there was no active kwin_x11 to replace... After automatically restarting kwin was working okay (except for the  configuration of  window title bar configuration).

P.S. I am wondering what is the correct method to reclaim my KDE session that is unusable because of apparent kwin corruption. The method of running "kwin_x11" manually (here used option --replace that I saw in the process listing prior to sending SIGHUP) works okay except for the fact that the GUI configuration is not fully applied (window bar font sizes much bigger than my configuration - could not change that with system settings since it just crashed :-).

- Unusual behavior I noticed:

By corrupted kwin_x11 above, I mean that keyboard or mouse events show portions of window contents in seemingly random places. Clicking anything or switching windows/desktops by keyboard hot keys is impossible.

-- 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 0x7f6144991800 (LWP 14044))]

Thread 2 (Thread 0x7f610f702700 (LWP 14114)):
#0  0x00007f6144494743 in select () at ../sysdeps/unix/syscall-template.S:81
#1  0x00007f6142a82101 in qt_safe_select (nfds=19, fdread=fdread@entry=0x7f6108000a78, fdwrite=fdwrite@entry=0x7f6108000d08, fdexcept=fdexcept@entry=0x7f6108000f98, orig_timeout=orig_timeout@entry=0x0) at kernel/qcore_unix.cpp:75
#2  0x00007f6142a83cd2 in select (timeout=0x0, exceptfds=0x7f6108000f98, writefds=0x7f6108000d08, readfds=0x7f6108000a78, nfds=<optimized out>, this=0x7f61080008c0) at kernel/qeventdispatcher_unix.cpp:320
#3  QEventDispatcherUNIXPrivate::doSelect (this=this@entry=0x7f61080008e0, flags=..., flags@entry=..., timeout=timeout@entry=0x0) at kernel/qeventdispatcher_unix.cpp:196
#4  0x00007f6142a84275 in QEventDispatcherUNIX::processEvents (this=0x7f61080008c0, flags=...) at kernel/qeventdispatcher_unix.cpp:607
#5  0x00007f6142a2b3e2 in QEventLoop::exec (this=this@entry=0x7f610f701da0, flags=..., flags@entry=...) at kernel/qeventloop.cpp:204
#6  0x00007f61427eab44 in QThread::exec (this=<optimized out>) at thread/qthread.cpp:503
#7  0x00007f613c643f65 in ?? () from /usr/lib/x86_64-linux-gnu/libQt5Qml.so.5
#8  0x00007f61427efb0e in QThreadPrivate::start (arg=0x2107790) at thread/qthread_unix.cpp:337
#9  0x00007f6143d0f6aa in start_thread (arg=0x7f610f702700) at pthread_create.c:333
#10 0x00007f614449deed in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

Thread 1 (Thread 0x7f6144991800 (LWP 14044)):
[KCrash Handler]
#6  0x00007f613c5d8dd4 in ?? () from /usr/lib/x86_64-linux-gnu/libQt5Qml.so.5
#7  0x00007f613c5d6804 in QQmlMetaType::qmlSingletonTypes() () from /usr/lib/x86_64-linux-gnu/libQt5Qml.so.5
#8  0x00007f613c5a92e8 in QQmlEngine::~QQmlEngine() () from /usr/lib/x86_64-linux-gnu/libQt5Qml.so.5
#9  0x00007f613c5a9499 in QQmlEngine::~QQmlEngine() () from /usr/lib/x86_64-linux-gnu/libQt5Qml.so.5
#10 0x00007f61443d0d32 in __run_exit_handlers (status=1, listp=0x7f614475b698 <__exit_funcs>, run_list_atexit=run_list_atexit@entry=true) at exit.c:82
#11 0x00007f61443d0d85 in __GI_exit (status=<optimized out>) at exit.c:104
#12 0x00007f612e6e97ce in QXcbConnection::processXcbEvents (this=0xc11c70) at qxcbconnection.cpp:1246
#13 0x00007f6142a5f73a in QObject::event (this=0xc11c70, e=<optimized out>) at kernel/qobject.cpp:1245
#14 0x00007f6143337b2c in QApplicationPrivate::notify_helper (this=0xc0aa00, receiver=0xc11c70, e=0x7f61280012f0) at kernel/qapplication.cpp:3720
#15 0x00007f614333d000 in QApplication::notify (this=0x7fff8f3fd380, receiver=0xc11c70, e=0x7f61280012f0) at kernel/qapplication.cpp:3503
#16 0x00007f6142a2dc2b in QCoreApplication::notifyInternal (this=0x7fff8f3fd380, receiver=0xc11c70, event=event@entry=0x7f61280012f0) at kernel/qcoreapplication.cpp:935
#17 0x00007f6142a2fc9b in sendEvent (event=0x7f61280012f0, receiver=<optimized out>) at ../../include/QtCore/../../src/corelib/kernel/qcoreapplication.h:228
#18 QCoreApplicationPrivate::sendPostedEvents (receiver=receiver@entry=0x0, event_type=event_type@entry=0, data=0xbfb2f0) at kernel/qcoreapplication.cpp:1552
#19 0x00007f6142a84112 in QEventDispatcherUNIX::processEvents (this=0xc39800, flags=flags@entry=...) at kernel/qeventdispatcher_unix.cpp:579
#20 0x00007f612e73f96d in QUnixEventDispatcherQPA::processEvents (this=<optimized out>, flags=...) at eventdispatchers/qunixeventdispatcher.cpp:62
#21 0x00007f6142a2b3e2 in QEventLoop::exec (this=this@entry=0x7fff8f3fd2a0, flags=..., flags@entry=...) at kernel/qeventloop.cpp:204
#22 0x00007f6142a3302c in QCoreApplication::exec () at kernel/qcoreapplication.cpp:1188
#23 0x00007f6142d7231c in QGuiApplication::exec () at kernel/qguiapplication.cpp:1510
#24 0x00007f61433337a5 in QApplication::exec () at kernel/qapplication.cpp:2956
#25 0x00007f6144766320 in kdemain (argc=3, argv=0x7fff8f3fd4e8) at ../main_x11.cpp:300
#26 0x00007f61443b7a40 in __libc_start_main (main=0x4007a0 <main(int, char**)>, argc=3, argv=0x7fff8f3fd4e8, init=<optimized out>, fini=<optimized out>, rtld_fini=<optimized out>, stack_end=0x7fff8f3fd4d8) at libc-start.c:289
#27 0x00000000004007d9 in _start ()

Possible duplicates by query: bug 353624, bug 352548, bug 342130, bug 342129.

Reported using DrKonqi