Bug 353681

Application: plasmashell (5.4.1)

Qt Version: 5.5.0
Operating System: Linux 4.1.3-201.fc22.x86_64 x86_64
Distribution: "Fedora release 22 (Twenty Two)"

-- Information about the crash:
System information:
This is a dual-monitor setup with LVDS (driven by intel) and an external monitor (driven by nouveau). The external monitor is my primary display.

What I was doing when the application crashed:
I logged out from KDE and back into it.  The KDE desktop (panel etc.) first started appearing on the LVDS, then I briefly saw an "oops" popup (hardly readable) on the LVDS.  At that time, either xorg or KDE decided that the KDE desktop (panel etc.)  should actually be shown on the external monitor -- after some delay, this happened, and then the Crash Reporting Assistant appeared pointing to the plasmashell segfault.

Unusual behavior I noticed:
Since I upgraded (on 7. Oct. 2015) to
  xorg-x11-server-Xorg.x86_64 1.17.2-2.fc22.2
  xorg-x11-server-Xwayland.x86_64 1.17.2-2.fc22.2    
  xorg-x11-server-common.x86_64 1.17.2-2.fc22.2    
  xorg-x11-drv-libinput.x86_64 0.14.0-1.fc22

KDE often comes up (after boot / first login) without any widgets on the external monitor (primary display), just showing the KDE menu, and with the LVDS having a black background (but otherwise working).  I found that a logout/login cycle often fixes this problem (which is what I did here).

Also, KDE with the new xorg has more difficulty to decide where the primary display is located -- and during KDE startup, the primary display (KDE panel etc.) is being visibly moved from LVDS to ext. monitor.

This was not the case with the previous xorg-x11 version
  xorg-x11-server-Xorg.x86_64 1.17.1-11.fc22
  xorg-x11-server-Xwayland.x86_64 1.17.1-11.fc22     
  xorg-x11-server-common.x86_64 1.17.1-11.fc22     
  xorg-x11-drv-libinput.x86_64 0.9.0-1.fc22

This is the first time I'm able to provide crash information on Fedora 22, thanks to this bugfix from Rex Dieter (applied today):
https://bugzilla.redhat.com/show_bug.cgi?id=1264486
Drop hard dependency on drkonqi, to allow removal and workaround apparent
 runtime conflicts with kf5's drkonqi.

The crash can be reproduced sometimes.

-- Backtrace:
Application: Plasma (plasmashell), signal: Segmentation fault
Using host libthread_db library "/lib64/libthread_db.so.1".
81	T_PSEUDO (SYSCALL_SYMBOL, SYSCALL_NAME, SYSCALL_NARGS)
[Current thread is 1 (Thread 0x7ff1bfb51900 (LWP 19681))]

Thread 8 (Thread 0x7ff1b832c700 (LWP 19687)):
#0  0x0000003f4e0f72fd in poll () at ../sysdeps/unix/syscall-template.S:81
#1  0x0000003f5200a182 in _xcb_conn_wait (__timeout=-1, __nfds=1, __fds=0x7ff1b832bbc0) at /usr/include/bits/poll2.h:46
#2  0x0000003f5200a182 in _xcb_conn_wait (c=c@entry=0xe89430, cond=cond@entry=0xe89470, vector=vector@entry=0x0, count=count@entry=0x0) at xcb_conn.c:459
#3  0x0000003f5200bc77 in xcb_wait_for_event (c=0xe89430) at xcb_in.c:648
#4  0x00007ff1b8fe5999 in QXcbEventReader::run() (this=0xe93b00) at qxcbconnection.cpp:1198
#5  0x0000003f62ca254e in QThreadPrivate::start(void*) (arg=0xe93b00) at thread/qthread_unix.cpp:331
#6  0x0000003f4e807555 in start_thread (arg=0x7ff1b832c700) at pthread_create.c:333
#7  0x0000003f4e102b9d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

Thread 7 (Thread 0x7ff1b5bc4700 (LWP 20055)):
#0  0x0000003f4e0f72fd in poll () at ../sysdeps/unix/syscall-template.S:81
#1  0x0000003f50449dbc in g_main_context_iterate (priority=2147483647, n_fds=1, fds=0x7ff1a8003070, timeout=<optimized out>, context=0x7ff1a8000990) at gmain.c:4103
#2  0x0000003f50449dbc in g_main_context_iterate (context=context@entry=0x7ff1a8000990, block=block@entry=1, dispatch=dispatch@entry=1, self=<optimized out>) at gmain.c:3803
#3  0x0000003f50449ecc in g_main_context_iteration (context=0x7ff1a8000990, may_block=may_block@entry=1) at gmain.c:3869
#4  0x0000003f62ed9dab in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) (this=0x7ff1a80008c0, flags=...) at kernel/qeventdispatcher_glib.cpp:420
#5  0x0000003f62e80daa in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) (this=this@entry=0x7ff1b5bc3ca0, flags=..., flags@entry=...) at kernel/qeventloop.cpp:204
#6  0x0000003f62c9d5a4 in QThread::exec() (this=this@entry=0xf68170) at thread/qthread.cpp:503
#7  0x0000003f77cd9245 in QQmlThreadPrivate::run() (this=0xf68170) at /usr/src/debug/qtdeclarative-opensource-src-5.5.0/src/qml/qml/ftw/qqmlthread.cpp:141
#8  0x0000003f62ca254e in QThreadPrivate::start(void*) (arg=0xf68170) at thread/qthread_unix.cpp:331
#9  0x0000003f4e807555 in start_thread (arg=0x7ff1b5bc4700) at pthread_create.c:333
#10 0x0000003f4e102b9d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

Thread 6 (Thread 0x7ff1ad2db700 (LWP 20118)):
#0  0x0000003f4e0f72fd in poll () at ../sysdeps/unix/syscall-template.S:81
#1  0x0000003f50449dbc in g_main_context_iterate (priority=2147483647, n_fds=1, fds=0x7ff1a4002e70, timeout=<optimized out>, context=0x7ff1a4000990) at gmain.c:4103
#2  0x0000003f50449dbc in g_main_context_iterate (context=context@entry=0x7ff1a4000990, block=block@entry=1, dispatch=dispatch@entry=1, self=<optimized out>) at gmain.c:3803
#3  0x0000003f50449ecc in g_main_context_iteration (context=0x7ff1a4000990, may_block=may_block@entry=1) at gmain.c:3869
#4  0x0000003f62ed9dab in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) (this=0x7ff1a40008c0, flags=...) at kernel/qeventdispatcher_glib.cpp:420
#5  0x0000003f62e80daa in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) (this=this@entry=0x7ff1ad2daca0, flags=..., flags@entry=...) at kernel/qeventloop.cpp:204
#6  0x0000003f62c9d5a4 in QThread::exec() (this=this@entry=0x1acaf30) at thread/qthread.cpp:503
#7  0x0000003f77cd9245 in QQmlThreadPrivate::run() (this=0x1acaf30) at /usr/src/debug/qtdeclarative-opensource-src-5.5.0/src/qml/qml/ftw/qqmlthread.cpp:141
#8  0x0000003f62ca254e in QThreadPrivate::start(void*) (arg=0x1acaf30) at thread/qthread_unix.cpp:331
#9  0x0000003f4e807555 in start_thread (arg=0x7ff1ad2db700) at pthread_create.c:333
#10 0x0000003f4e102b9d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

Thread 5 (Thread 0x7ff1a365b700 (LWP 20147)):
#0  0x0000003f4e0f72fd in poll () at ../sysdeps/unix/syscall-template.S:81
#1  0x0000003f50449dbc in g_main_context_iterate (priority=2147483647, n_fds=1, fds=0x7ff19c003070, timeout=<optimized out>, context=0x7ff19c000990) at gmain.c:4103
#2  0x0000003f50449dbc in g_main_context_iterate (context=context@entry=0x7ff19c000990, block=block@entry=1, dispatch=dispatch@entry=1, self=<optimized out>) at gmain.c:3803
#3  0x0000003f50449ecc in g_main_context_iteration (context=0x7ff19c000990, may_block=may_block@entry=1) at gmain.c:3869
#4  0x0000003f62ed9dab in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) (this=0x7ff19c0008c0, flags=...) at kernel/qeventdispatcher_glib.cpp:420
#5  0x0000003f62e80daa in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) (this=this@entry=0x7ff1a365aca0, flags=..., flags@entry=...) at kernel/qeventloop.cpp:204
#6  0x0000003f62c9d5a4 in QThread::exec() (this=this@entry=0x1bb88d0) at thread/qthread.cpp:503
#7  0x0000003f77cd9245 in QQmlThreadPrivate::run() (this=0x1bb88d0) at /usr/src/debug/qtdeclarative-opensource-src-5.5.0/src/qml/qml/ftw/qqmlthread.cpp:141
#8  0x0000003f62ca254e in QThreadPrivate::start(void*) (arg=0x1bb88d0) at thread/qthread_unix.cpp:331
#9  0x0000003f4e807555 in start_thread (arg=0x7ff1a365b700) at pthread_create.c:333
#10 0x0000003f4e102b9d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

Thread 4 (Thread 0x7ff1a1d53700 (LWP 20171)):
#0  0x0000003f4e80c540 in pthread_cond_wait@@GLIBC_2.3.2 () at ../sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S:185
#1  0x0000003f7a785494 in QTWTF::TCMalloc_PageHeap::scavengerThread() (this=0x3f7aa6de80) at /usr/src/debug/qtscript-opensource-src-5.5.0/src/3rdparty/javascriptcore/JavaScriptCore/wtf/FastMalloc.cpp:2359
#2  0x0000003f7a7854d9 in QTWTF::TCMalloc_PageHeap::runScavengerThread(void*) (context=<optimized out>) at /usr/src/debug/qtscript-opensource-src-5.5.0/src/3rdparty/javascriptcore/JavaScriptCore/wtf/FastMalloc.cpp:1464
#3  0x0000003f4e807555 in start_thread (arg=0x7ff1a1d53700) at pthread_create.c:333
#4  0x0000003f4e102b9d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

Thread 3 (Thread 0x7ff11864d700 (LWP 20220)):
#0  0x0000003f4e0f2fad in read () at ../sysdeps/unix/syscall-template.S:81
#1  0x0000003f5048db00 in g_wakeup_acknowledge (__nbytes=16, __buf=0x7ff11864ca50, __fd=<optimized out>) at /usr/include/bits/unistd.h:44
#2  0x0000003f5048db00 in g_wakeup_acknowledge (wakeup=0x7ff19c002780) at gwakeup.c:210
#3  0x0000003f504498b4 in g_main_context_check (context=context@entry=0x7ff110000990, max_priority=2147483647, fds=fds@entry=0x7ff110003120, n_fds=n_fds@entry=1) at gmain.c:3600
#4  0x0000003f50449d60 in g_main_context_iterate (context=context@entry=0x7ff110000990, block=block@entry=1, dispatch=dispatch@entry=1, self=<optimized out>) at gmain.c:3805
#5  0x0000003f50449ecc in g_main_context_iteration (context=0x7ff110000990, may_block=may_block@entry=1) at gmain.c:3869
#6  0x0000003f62ed9dab in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) (this=0x7ff1100008c0, flags=...) at kernel/qeventdispatcher_glib.cpp:420
#7  0x0000003f62e80daa in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) (this=this@entry=0x7ff11864cc50, flags=..., flags@entry=...) at kernel/qeventloop.cpp:204
#8  0x0000003f62c9d5a4 in QThread::exec() (this=this@entry=0x2601230) at thread/qthread.cpp:503
#9  0x0000003f788f6616 in QQuickPixmapReader::run() (this=0x2601230) at /usr/src/debug/qtdeclarative-opensource-src-5.5.0/src/quick/util/qquickpixmapcache.cpp:754
#10 0x0000003f62ca254e in QThreadPrivate::start(void*) (arg=0x2601230) at thread/qthread_unix.cpp:331
#11 0x0000003f4e807555 in start_thread (arg=0x7ff11864d700) at pthread_create.c:333
#12 0x0000003f4e102b9d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

Thread 2 (Thread 0x7ff10c873700 (LWP 20247)):
#0  0x0000003f50446ec4 in g_source_iter_clear (iter=iter@entry=0x7ff10c872ad0) at gmain.c:939
#1  0x0000003f504493d8 in g_main_context_prepare (context=context@entry=0x7ff108000990, priority=priority@entry=0x7ff10c872b50) at gmain.c:3473
#2  0x0000003f50449ceb in g_main_context_iterate (context=context@entry=0x7ff108000990, block=block@entry=1, dispatch=dispatch@entry=1, self=<optimized out>) at gmain.c:3788
#3  0x0000003f50449ecc in g_main_context_iteration (context=0x7ff108000990, may_block=may_block@entry=1) at gmain.c:3869
#4  0x0000003f62ed9dab in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) (this=0x7ff1080008c0, flags=...) at kernel/qeventdispatcher_glib.cpp:420
#5  0x0000003f62e80daa in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) (this=this@entry=0x7ff10c872c80, flags=..., flags@entry=...) at kernel/qeventloop.cpp:204
#6  0x0000003f62c9d5a4 in QThread::exec() (this=this@entry=0x4a46320) at thread/qthread.cpp:503
#7  0x00007ff10e4c2397 in KCupsConnection::run() (this=0x4a46320) at ../../libkcups/KCupsConnection.cpp:303
#8  0x0000003f62ca254e in QThreadPrivate::start(void*) (arg=0x4a46320) at thread/qthread_unix.cpp:331
#9  0x0000003f4e807555 in start_thread (arg=0x7ff10c873700) at pthread_create.c:333
#10 0x0000003f4e102b9d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

Thread 1 (Thread 0x7ff1bfb51900 (LWP 19681)):
[KCrash Handler]
#6  0x00007ff1af6f371f in brw_workaround_depthstencil_alignment (irb=0x253a150) at brw_misc_state.c:215
#7  0x00007ff1af6f371f in brw_workaround_depthstencil_alignment (brw=brw@entry=0x267a7f8, clear_mask=clear_mask@entry=50) at brw_misc_state.c:231
#8  0x00007ff1af67b883 in brw_clear (ctx=0x267a7f8, mask=50) at brw_clear.c:235
#9  0x0000003f789263fa in QSGBatchRenderer::Renderer::renderBatches() (this=this@entry=0x4cac610) at /usr/src/debug/qtdeclarative-opensource-src-5.5.0/src/quick/scenegraph/coreapi/qsgbatchrenderer.cpp:2471
#10 0x0000003f7892bde2 in QSGBatchRenderer::Renderer::render() (this=<optimized out>) at /usr/src/debug/qtdeclarative-opensource-src-5.5.0/src/quick/scenegraph/coreapi/qsgbatchrenderer.cpp:2674
#11 0x0000003f78937adf in QSGRenderer::renderScene(QSGBindable const&) (this=0x4cac610, bindable=...) at /usr/src/debug/qtdeclarative-opensource-src-5.5.0/src/quick/scenegraph/coreapi/qsgrenderer.cpp:208
#12 0x0000003f7893832b in QSGRenderer::renderScene(unsigned int) (this=<optimized out>, fboId=<optimized out>) at /usr/src/debug/qtdeclarative-opensource-src-5.5.0/src/quick/scenegraph/coreapi/qsgrenderer.cpp:168
#13 0x0000003f7894871e in QSGRenderContext::renderNextFrame(QSGRenderer*, unsigned int) (this=0x1808a80, renderer=0x4cac610, fboId=<optimized out>) at /usr/src/debug/qtdeclarative-opensource-src-5.5.0/src/quick/scenegraph/qsgcontext.cpp:558
#14 0x0000003f7899265b in QQuickWindowPrivate::renderSceneGraph(QSize const&) (this=this@entry=0x3fb2a90, size=...) at /usr/src/debug/qtdeclarative-opensource-src-5.5.0/src/quick/items/qquickwindow.cpp:383
#15 0x0000003f7896301b in QSGGuiThreadRenderLoop::renderWindow(QQuickWindow*) (this=this@entry=0x106be10, window=0x403fd70) at /usr/src/debug/qtdeclarative-opensource-src-5.5.0/src/quick/scenegraph/qsgrenderloop.cpp:375
#16 0x0000003f78964121 in QSGGuiThreadRenderLoop::event(QEvent*) (this=0x106be10, e=<optimized out>) at /usr/src/debug/qtdeclarative-opensource-src-5.5.0/src/quick/scenegraph/qsgrenderloop.cpp:471
#17 0x0000003f669544ac in QApplicationPrivate::notify_helper(QObject*, QEvent*) (this=this@entry=0xe7d480, receiver=receiver@entry=0x106be10, e=e@entry=0x7fff8678c360) at kernel/qapplication.cpp:3717
#18 0x0000003f66959976 in QApplication::notify(QObject*, QEvent*) (this=0x7fff8678c720, receiver=0x106be10, e=0x7fff8678c360) at kernel/qapplication.cpp:3500
#19 0x0000003f62e8361b in QCoreApplication::notifyInternal(QObject*, QEvent*) (this=0x7fff8678c720, receiver=0x106be10, event=event@entry=0x7fff8678c360) at kernel/qcoreapplication.cpp:965
#20 0x0000003f62ed8bad in QTimerInfoList::activateTimers() (event=0x7fff8678c360, receiver=<optimized out>) at ../../src/corelib/kernel/qcoreapplication.h:224
#21 0x0000003f62ed8bad in QTimerInfoList::activateTimers() (this=0xebe910) at kernel/qtimerinfo_unix.cpp:637
#22 0x0000003f62ed90b1 in timerSourceDispatch(GSource*, GSourceFunc, gpointer) (source=<optimized out>) at kernel/qeventdispatcher_glib.cpp:177
#23 0x0000003f50449a8a in g_main_context_dispatch (context=0x7ff1b00016f0) at gmain.c:3122
#24 0x0000003f50449a8a in g_main_context_dispatch (context=context@entry=0x7ff1b00016f0) at gmain.c:3737
#25 0x0000003f50449e20 in g_main_context_iterate (context=context@entry=0x7ff1b00016f0, block=block@entry=1, dispatch=dispatch@entry=1, self=<optimized out>) at gmain.c:3808
#26 0x0000003f50449ecc in g_main_context_iteration (context=0x7ff1b00016f0, may_block=may_block@entry=1) at gmain.c:3869
#27 0x0000003f62ed9d8f in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) (this=0xec0f10, flags=...) at kernel/qeventdispatcher_glib.cpp:418
#28 0x0000003f62e80daa in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) (this=this@entry=0x7fff8678c5a0, flags=..., flags@entry=...) at kernel/qeventloop.cpp:204
#29 0x0000003f62e88e6c in QCoreApplication::exec() () at kernel/qcoreapplication.cpp:1229
#30 0x0000003f634e724c in QGuiApplication::exec() () at kernel/qguiapplication.cpp:1528
#31 0x0000003f669508e5 in QApplication::exec() () at kernel/qapplication.cpp:2977
#32 0x00000000004302c3 in main(int, char**) (argc=2, argv=<optimized out>) at ../../shell/main.cpp:176

Possible duplicates by query: bug 353001, bug 352678, bug 351509, bug 343756.

Reported using DrKonqi