Application: kwin_x11 (5.8.7)

Qt Version: 5.9.1
Frameworks Version: 5.41.0
Operating System: Linux 4.14.8-mc2-easy x86_64

-- Information about the crash:
- What I was doing when the application crashed:

Note: All my Plasma/KWin settings are the default ones from KDE upstream.  I haven't changed any effects or settings other than focus follows mouse, and using plastiK Aurorae theme.

There's another crash in KWin that I am trying to debug involving ffplay.  While attempting to debug that crash, I used Alt+Tab to cycle through windows to reach Firefox.  KWin had already crashed one time.  I noticed that on the thumbnail bar (left third of screen), the Firefox window that was at the bottom of the list had no thumbnail.  When I reached it, and it became highlighted, KWin immediately crashed.  Upon relaunching, the Firefox window still had no thumbnail, and using Alt+Tab again caused the same crash with the same backtrace.  Repeated once again, and now thumbnails are no longer showing up because compositing was disabled.  Re-enabling compositing now causes Alt+Tab to always crash.



Version
=======
KWin version: 5.8.7
Qt Version: 5.9.1
Qt compile version: 5.9.1
XCB compile version: 1.12

Operation Mode: X11 only

Build Options
=============
KWIN_BUILD_DECORATIONS: yes
KWIN_BUILD_TABBOX: yes
KWIN_BUILD_ACTIVITIES: yes
HAVE_INPUT: yes
HAVE_DRM: yes
HAVE_GBM: yes
HAVE_X11_XCB: yes
HAVE_EPOXY_GLX: yes
HAVE_WAYLAND_EGL: yes

X11
===
Vendor: The X.Org Foundation
Vendor Release: 11903000
Protocol Version/Revision: 11/0
SHAPE: yes; Version: 0x11
RANDR: yes; Version: 0x14
DAMAGE: yes; Version: 0x11
Composite: yes; Version: 0x4
RENDER: yes; Version: 0xb
XFIXES: yes; Version: 0x50
SYNC: yes; Version: 0x31
GLX: yes; Version: 0x0

Decoration
==========
Plugin: org.kde.kwin.aurorae
Theme: kwin4_decoration_qml_plastik
Blur: 1
onAllDesktopsAvailable: false
alphaChannelSupported: true
closeOnDoubleClickOnMenu: false
decorationButtonsLeft: 5, 4, 3, 7, 0
decorationButtonsRight: 6
borderSize: 2
gridUnit: 10
font: Noto Sans,10,-1,0,50,0,0,0,0,0
smallSpacing: 2
largeSpacing: 10

Options
=======
focusPolicy: 1
nextFocusPrefersMouse: false
clickRaise: true
autoRaise: false
autoRaiseInterval: 750
delayFocusInterval: 300
shadeHover: false
shadeHoverInterval: 250
separateScreenFocus: false
placement: 4
focusPolicyIsReasonable: true
borderSnapZone: 10
windowSnapZone: 10
centerSnapZone: 0
snapOnlyWhenOverlapping: false
rollOverDesktops: true
focusStealingPreventionLevel: 1
legacyFullscreenSupport: false
operationTitlebarDblClick: 5000
operationMaxButtonLeftClick: 5000
operationMaxButtonMiddleClick: 5015
operationMaxButtonRightClick: 5014
commandActiveTitlebar1: 0
commandActiveTitlebar2: 30
commandActiveTitlebar3: 2
commandInactiveTitlebar1: 4
commandInactiveTitlebar2: 30
commandInactiveTitlebar3: 2
commandWindow1: 7
commandWindow2: 8
commandWindow3: 8
commandWindowWheel: 31
commandAll1: 10
commandAll2: 3
commandAll3: 14
keyCmdAllModKey: 16777251
showGeometryTip: false
condensedTitle: false
electricBorderMaximize: true
electricBorderTiling: true
electricBorderCornerRatio: 0.25
borderlessMaximizedWindows: false
killPingTimeout: 5000
hideUtilityWindowsForInactive: true
inactiveTabsSkipTaskbar: false
autogroupSimilarWindows: false
autogroupInForeground: true
compositingMode: 1
useCompositing: true
compositingInitialized: true
hiddenPreviews: 1
glSmoothScale: 2
colorCorrected: false
xrenderSmoothScale: false
maxFpsInterval: 16666666
refreshRate: 0
vBlankTime: 6000000
glStrictBinding: true
glStrictBindingFollowsDriver: true
glCoreProfile: false
glPreferBufferSwap: 101
glPlatformInterface: 1
windowsBlockCompositing: true

Screen Edges
============
desktopSwitching: false
desktopSwitchingMovingClients: false
cursorPushBackDistance: 1x1
timeThreshold: 150
reActivateThreshold: 350
actionTopLeft: 0
actionTop: 0
actionTopRight: 0
actionRight: 0
actionBottomRight: 0
actionBottom: 0
actionBottomLeft: 0
actionLeft: 0

Screens
=======
Multi-Head: no
Active screen follows mouse:  yes
Number of Screens: 1

Screen 0:
---------
Name: DVI-0
Geometry: 0,0,1920x1080
Refresh Rate: 60


Compositing
===========
Compositing is active
Compositing Type: OpenGL
OpenGL vendor string: X.Org
OpenGL renderer string: AMD CAICOS (DRM 2.50.0 / 4.14.8-mc2-easy, LLVM 4.0.0)
OpenGL version string: 3.0 Mesa 17.3.1
OpenGL platform interface: GLX
OpenGL shading language version string: 1.30
Driver: Unknown
GPU class: Unknown
OpenGL version: 3.0
GLSL version: 1.30
Mesa version: 17.3.1
X server version: 1.19.3
Linux kernel version: 4.14.8
Direct rendering: Requires strict binding: yes
GLSL shaders:  yes
Texture NPOT support:  yes
Virtual Machine:  no
OpenGL 2 Shaders are used
Painting blocks for vertical retrace:  no

Loaded Effects:
---------------
zoom
kwin4_effect_login
kwin4_effect_translucency
kwin4_effect_fade
kwin4_effect_windowaperture
kwin4_effect_dialogparent
kwin4_effect_maximize
kwin4_effect_morphingpopups
slidingpopups
slide
screenshot
minimizeanimation
desktopgrid
presentwindows
highlightwindow
blur
contrast
startupfeedback
screenedge
kscreen

Currently Active Effects:
-------------------------
blur
contrast

Effect Settings:
----------------
zoom:
zoomFactor: 1.2
mousePointer: 0
mouseTracking: 0
enableFocusTracking: false
followFocus: true
focusDelay: 350
moveFactor: 20
targetZoom: 1

kwin4_effect_login:

kwin4_effect_translucency:

kwin4_effect_fade:

kwin4_effect_windowaperture:

kwin4_effect_dialogparent:

kwin4_effect_maximize:

kwin4_effect_morphingpopups:

slidingpopups:
fadeInTime: 150
fadeOutTime: 250

slide:

screenshot:

minimizeanimation:

desktopgrid:
zoomDuration: 300
border: 10
desktopNameAlignment: 0
layoutMode: 0
customLayoutRows: 2
usePresentWindows: true

presentwindows:
layoutMode: 0
showCaptions: true
showIcons: true
doNotCloseWindows: false
ignoreMinimized: false
accuracy: 20
fillGaps: true
fadeDuration: 150
showPanel: false
leftButtonWindow: 1
rightButtonWindow: 2
middleButtonWindow: 0
leftButtonDesktop: 2
middleButtonDesktop: 0
rightButtonDesktop: 0

highlightwindow:

blur:
blurRadius: 12
cacheTexture: true

contrast:

startupfeedback:
type: 1

screenedge:

kscreen:

The crash can be reproduced every time.

-- Backtrace:
Application: KWin (kwin_x11), signal: Segmentation fault
[KCrash Handler]
#8  0x00007f8036f682f5 in r600_draw_vbo (ctx=0x55e38272a7e0, info=0x7fffaa0b4350) at r600_state_common.c:1937
#9  0x00007f8036d2f201 in u_vbuf_draw_vbo (mgr=0x55e38279bbe0, info=<optimized out>) at util/u_vbuf.c:1142
#10 0x00007f8036ae4003 in st_draw_vbo (ctx=<optimized out>, prims=0x7fffaa0b4430, nr_prims=<optimized out>, ib=0x7fffaa0b4410, index_bounds_valid=<optimized out>, min_index=<optimized out>, max_index=<optimized out>, tfb_vertcount=0x0, stream=0, indirect=0x0) at state_tracker/st_draw.c:227
#11 0x00007f8036aa39b9 in vbo_validated_drawrangeelements (ctx=ctx@entry=0x55e3827a1ee0, mode=mode@entry=5, index_bounds_valid=index_bounds_valid@entry=0 '\000', start=start@entry=0, end=end@entry=4294967295, count=count@entry=4, type=5123, indices=0x2, basevertex=0, numInstances=1, baseInstance=0) at vbo/vbo_exec_array.c:925
#12 0x00007f8036aa42c2 in vbo_exec_DrawElements (mode=5, count=4, type=5123, indices=0x2) at vbo/vbo_exec_array.c:1075
#13 0x00007f804bceb037 in QSGBatchRenderer::Renderer::renderMergedBatch(QSGBatchRenderer::Batch const*) () from /usr/lib/libQt5Quick.so.5
#14 0x00007f804bcec3f5 in QSGBatchRenderer::Renderer::renderBatches() () from /usr/lib/libQt5Quick.so.5
#15 0x00007f804bcf1e41 in QSGBatchRenderer::Renderer::render() () from /usr/lib/libQt5Quick.so.5
#16 0x00007f804bce1fe6 in QSGRenderer::renderScene(QSGBindable const&) () from /usr/lib/libQt5Quick.so.5
#17 0x00007f804bce253f in QSGRenderer::renderScene(unsigned int) () from /usr/lib/libQt5Quick.so.5
#18 0x00007f804bd1f0f2 in QSGDefaultRenderContext::renderNextFrame(QSGRenderer*, unsigned int) () from /usr/lib/libQt5Quick.so.5
#19 0x00007f804bd7faad in QQuickWindowPrivate::renderSceneGraph(QSize const&) () from /usr/lib/libQt5Quick.so.5
#20 0x00007f804bd10b42 in ?? () from /usr/lib/libQt5Quick.so.5
#21 0x00007f804bd8a555 in QQuickWindow::event(QEvent*) () from /usr/lib/libQt5Quick.so.5
#22 0x00007f7fa99caea3 in PlasmaQuick::Dialog::event (this=0x55e381ad8d60, event=0x7fffaa0b4f20) at /usr/src/packages/user/plasma-framework/src/plasma-framework-5.41.0/src/plasmaquick/dialog.cpp:1169
#23 0x00007f8051b03fdc in QApplicationPrivate::notify_helper (this=<optimized out>, receiver=0x55e381ad8d60, e=0x7fffaa0b4f20) at kernel/qapplication.cpp:3717
#24 0x00007f8051b0b8d9 in QApplication::notify (this=0x7fffaa0b5650, receiver=0x55e381ad8d60, e=0x7fffaa0b4f20) at kernel/qapplication.cpp:3476
#25 0x00007f8050dc3fc0 in QCoreApplication::notifyInternal2(QObject*, QEvent*) () from /usr/lib/libQt5Core.so.5
#26 0x00007f805135131e in QWindowPrivate::deliverUpdateRequest() () from /usr/lib/libQt5Gui.so.5
#27 0x00007f8051351859 in QWindow::event(QEvent*) () from /usr/lib/libQt5Gui.so.5
#28 0x00007f804bd8a4f5 in QQuickWindow::event(QEvent*) () from /usr/lib/libQt5Quick.so.5
#29 0x00007f7fa99caea3 in PlasmaQuick::Dialog::event (this=0x55e381ad8d60, event=0x7fffaa0b5390) at /usr/src/packages/user/plasma-framework/src/plasma-framework-5.41.0/src/plasmaquick/dialog.cpp:1169
#30 0x00007f8051b03fdc in QApplicationPrivate::notify_helper (this=<optimized out>, receiver=0x55e381ad8d60, e=0x7fffaa0b5390) at kernel/qapplication.cpp:3717
#31 0x00007f8051b0b8d9 in QApplication::notify (this=0x7fffaa0b5650, receiver=0x55e381ad8d60, e=0x7fffaa0b5390) at kernel/qapplication.cpp:3476
#32 0x00007f8050dc3fc0 in QCoreApplication::notifyInternal2(QObject*, QEvent*) () from /usr/lib/libQt5Core.so.5
#33 0x00007f8050e18d5e in QTimerInfoList::activateTimers() () from /usr/lib/libQt5Core.so.5
#34 0x00007f8050e1706a in QEventDispatcherUNIX::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/libQt5Core.so.5
#35 0x00007f803c5a81bf in QUnixEventDispatcherQPA::processEvents (this=<optimized out>, flags=...) at qunixeventdispatcher.cpp:68
#36 0x00007f8050dc1f2a in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/libQt5Core.so.5
#37 0x00007f8050dcaf74 in QCoreApplication::exec() () from /usr/lib/libQt5Core.so.5
#38 0x00007f80536c225c in kdemain (argc=<optimized out>, argv=0x7fffaa0b5748) at /usr/src/packages/user/kwin/src/kwin-5.8.7/main_x11.cpp:466
#39 0x00007f80538e6866 in __libc_start_main (main=0x55e38092c6d0 <main>, argc=3, argv=0x7fffaa0b5748) at src/env/__libc_start_main.c:74
#40 0x000055e38092c718 in _start_c (p=<optimized out>) at crt/crt1.c:17
#41 0x000055e38092c6f0 in _start ()

Possible duplicates by query: bug 322168, bug 320354.

Reported using DrKonqi