Bug 951109

Summary: kwin crashes when KDE desktop gets maximized in VNC
Product: [Fedora] Fedora Reporter: Karsten Hopp <karsten>
Component: qtAssignee: Daniel Vrátil <dvratil>
Status: CLOSED CURRENTRELEASE QA Contact: Fedora Extras Quality Assurance <extras-qa>
Severity: high Docs Contact:
Priority: medium    
Version: 19CC: dvratil, itamar, jeischma, jgrulich, jreznik, kevin, ltinkl, mbriza, rdieter, rnovacek, smparrish, than
Target Milestone: ---   
Target Release: ---   
Hardware: ppc64   
OS: Linux   
Whiteboard:
Fixed In Version: Doc Type: Bug Fix
Doc Text:
Story Points: ---
Clone Of: Environment:
Last Closed: 2013-06-20 13:35:54 UTC Type: Bug
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Embargoed:
Bug Depends On:    
Bug Blocks: 920769    
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Description Flags
kcrash file none

Description Karsten Hopp 2013-04-11 13:44:54 UTC
Created attachment 734209 [details]
kcrash file

Description of problem:
I was running KDE on a PPC64 machine in a vncserver. When I maximized the vncviewer window on my local machine, kwin crashed with the attached backtrace

Version-Release number of selected component (if applicable):
kde-workspace-4.10.1-2.fc19

Comment 1 Rex Dieter 2013-04-11 14:05:06 UTC
Hrm, after looking at bug #951103 , I see that these both died in the same lll_futex_wait function.  Here,

Application: KWin (kwin), signal: Segmentation fault
Using host libthread_db library "/lib64/libthread_db.so.1".
155	      lll_futex_wait (&cond->__data.__futex, futex_val, pshared);
[Current thread is 1 (Thread 0x3fff8cd3c290 (LWP 8166))]

Comment 2 Kevin Kofler 2013-04-11 15:25:46 UTC
When looking at a crash of a multithreaded program, the first thing to do is to identify the active thread, usually the only relevant one. Any thread stuck in something like lll_futex_wait, __lll_lock_wait etc. is NOT active. (Sadly, the wrong thread is current in GDB for some reason.)

This one is crashing in QCoreApplicationPrivate::sendPostedEvents, maybe a Qt bug?

Comment 3 Than Ngo 2013-05-22 16:25:58 UTC
it's crashed in libkscreen.so, Dan you can ask karsten to get account on ppc.

Comment 4 Daniel Vrátil 2013-05-24 16:59:05 UTC
Assigning back to kde-workspace. This is definitely not a KScreen crash :-) 
Anyway, can you please try to reproduce the crash with this Qt build?

http://ppc.koji.fedoraproject.org/scratch/dvratil/task_1128748/

It has a patch [0] that should solve crashes when using DBus from multiple threads.


[0] https://codereview.qt-project.org/#change,55874

Comment 5 Than Ngo 2013-05-28 15:35:13 UTC
Karsten cannot reproduce the crash aynmore with new qt update. reassign to correct qt component. I'm building new qt and will add it to f19 update today

Dan, good catch! thanks

Comment 6 Fedora Update System 2013-05-28 15:38:05 UTC
qt-4.8.4-18.fc19 has been submitted as an update for Fedora 19.
https://admin.fedoraproject.org/updates/qt-4.8.4-18.fc19

Comment 7 Fedora Update System 2013-05-29 17:43:51 UTC
Package qt-4.8.4-18.fc19:
* should fix your issue,
* was pushed to the Fedora 19 testing repository,
* should be available at your local mirror within two days.
Update it with:
# su -c 'yum update --enablerepo=updates-testing qt-4.8.4-18.fc19'
as soon as you are able to.
Please go to the following url:
https://admin.fedoraproject.org/updates/FEDORA-2013-9546/qt-4.8.4-18.fc19
then log in and leave karma (feedback).

Comment 8 Fedora Update System 2013-05-30 20:03:48 UTC
qt-4.8.4-19.fc19 has been submitted as an update for Fedora 19.
https://admin.fedoraproject.org/updates/qt-4.8.4-19.fc19

Comment 9 Than Ngo 2013-06-20 13:35:54 UTC
it doesn't crash after update to latest version