nepomukservicestub crashed with SIGSEGV in select()

[Max]

when I bootup
this is crash

ProblemType: Crash
DistroRelease: Ubuntu 12.04
Package: kde-runtime 4:4.7.95-0ubuntu1
ProcVersionSignature: Ubuntu 3.2.0-7.13-generic-pae 3.2.0-rc7
Uname: Linux 3.2.0-7-generic-pae i686
ApportVersion: 1.90-0ubuntu1
Architecture: i386
Date: Wed Jan 4 23:56:53 2012
Disassembly: => 0x0: Cannot access memory at address 0x0
ExecutablePath: /usr/bin/nepomukservicestub
InstallationMedia: Kubuntu 12.04 LTS "Precise Pangolin" - Alpha i386 (20120104)
ProcCmdline: /usr/bin/nepomukservicestub nepomukstorage
SegvAnalysis:
 Segfault happened at: 0x0: Cannot access memory at address 0x0
 PC (0x00000000) not located in a known VMA region (needed executable region)!
SegvReason: executing NULL VMA
Signal: 11
SourcePackage: kde-runtime
StacktraceTop:
 ?? ()
 QObject::~QObject() () from /usr/lib/i386-linux-gnu/libQtCore.so.4
 QObject::~QObject() () from /usr/lib/i386-linux-gnu/libQtCore.so.4
 _start ()
Title: nepomukservicestub crashed with SIGSEGV in QObject::~QObject()
UpgradeStatus: No upgrade log present (probably fresh install)
UserGroups: adm cdrom dip lpadmin plugdev sambashare sudo vboxusers

[Apport retracing service (apport)]

StacktraceTop:
 select () at ../sysdeps/unix/syscall-template.S:82
 qt_safe_select (nfds=22, fdread=0xbf8dfb4c, fdwrite=0xbf8dfbcc, fdexcept=0x0, orig_timeout=0xbf8dfaf8) at kernel/qcore_unix.cpp:92
 select_msecs (nfds=22, fdread=0xbf8dfb4c, fdwrite=0xbf8dfbcc, timeout=29983) at io/qprocess_unix.cpp:888
 QProcessPrivate::waitForFinished (this=0x8c9f428, msecs=30000) at io/qprocess_unix.cpp:1104
 QProcess::waitForFinished (this=0x8c9efb0, msecs=30000) at io/qprocess.cpp:1742

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[Ddfrazier82 (ddfrazier82)]

Application: nepomukservicestub (0.2)
KDE Platform Version: 4.7.2 (4.7.2) "release 5"
Qt Version: 4.7.4
Operating System: Linux 3.1.9-1.4-desktop x86_64
Distribution: "openSUSE 12.1 (x86_64)"

-- Information about the crash:
- What I was doing when the application crashed:
Restarting my computer. It happens every time I do so. It only worked for the first few days I installed KDE.

The crash can be reproduced every time.

-- Backtrace:
Application: Nepomuk Service Stub (nepomukservicestub), signal: Segmentation fault
[Current thread is 1 (Thread 0x7f6598b8f760 (LWP 9699))]

Thread 13 (Thread 0x7f657ffff700 (LWP 9748)):
#0 0x00007f6595ff8523 in poll () from /lib64/libc.so.6
#1 0x00007f659544ea98 in ?? () from /usr/lib64/libglib-2.0.so.0
#2 0x00007f659544ef59 in g_main_context_iteration () from /usr/lib64/libglib-2.0.so.0
#3 0x00007f65986a6586 in QEventDispatcherGlib::processEvents (this=0x7f65740008c0, flags=<optimized out>) at kernel/qeventdispatcher_glib.cpp:424
#4 0x00007f659867aa32 in QEventLoop::processEvents (this=<optimized out>, flags=...) at kernel/qeventloop.cpp:149
#5 0x00007f659867ac2f in QEventLoop::exec (this=0x7f657fffedf0, flags=...) at kernel/qeventloop.cpp:201
#6 0x00007f65985925df in QThread::exec (this=<optimized out>) at thread/qthread.cpp:498
#7 0x00007f659865daff in QInotifyFileSystemWatcherEngine::run (this=0x8958f0) at io/qfilesystemwatcher_inotify.cpp:248
#8 0x00007f6598595025 in QThreadPrivate::start (arg=0x8958f0) at thread/qthread_unix.cpp:331
#9 0x00007f6598304f05 in start_thread () from /lib64/libpthread.so.0
#10 0x00007f659600163d in clone () from /lib64/libc.so.6

Thread 12 (Thread 0x7f657f7fe700 (LWP 9791)):
#0 0x00007fff877b88de in ?? ()
#1 0x00007f6595702e91 in clock_gettime () from /lib64/librt.so.1
#2 0x00007f65985e5114 in do_gettime (frac=0x7f657f7fdb58, sec=0x7f657f7fdb50) at tools/qelapsedtimer_unix.cpp:123
#3 qt_gettime () at tools/qelapsedtimer_unix.cpp:140
#4 0x00007f65986a6d2d in QTimerInfoList::updateCurrentTime (this=0x7f6578001ed0) at kernel/qeventdispatcher_unix.cpp:339
#5 0x00007f65986a7063 in QTimerInfoList::timerWait (this=0x7f6578001ed0, tm=...) at kernel/qeventdispatcher_unix.cpp:442
#6 0x00007f65986a5acc in timerSourcePrepareHelper (src=<optimized out>, timeout=0x7f657f7fdc3c) at kernel/qeventdispatcher_glib.cpp:136
#7 0x00007f65986a5b75 in timerSourcePrepare (source=<optimized out>, timeout=<optimized out>) at kernel/qeventdispatcher_glib.cpp:169
#8 0x00007f659544db22 in g_main_context_prepare () from /usr/lib64/libglib-2.0.so.0
#9 0x00007f659544e92d in ?? () from /usr/lib64/libglib-2.0.so.0
#10 0x00007f659544ef59 in g_main_context_iteration () from /usr/lib64/libglib-2.0.so.0
#11 0x00007f65986a6586 in QEventDispatcherGlib::processEvents (this=0x7f6578006240, flags=<optimized out>) at kernel/qeventdispatcher_glib.cpp:424
#12 0x00007f659867aa32 in QEventLoop::processEvents (this=<optimized out>, flags=...) at kernel/qeventloop.cpp:149
#13 0x00007f659867ac2f in QEventLoop::exec (this=0x7f657f7fddd0, flags=...) at kernel/qeventloop.cpp:201
#14 0x00007f65985925df in QThread::exec (this=<optimized out>) at thread/qthread.cpp:498
#15 0x00007f658a006078 in Soprano::Server::DB...

[adaptee (adaptee)]

*** Bug 292356 has been marked as a duplicate of this bug. ***

[Me-ngeefk4xayt3t4u9watah405ve (me-ngeefk4xayt3t4u9watah405ve)]

It seems that one of Soprano::FilterModels does not have a parent, and is asserting cause of that. That is weird cause all the models always have parents, and their parents never ever change.

I'm not sure what to do of this bug report.

[Me-ngeefk4xayt3t4u9watah405ve (me-ngeefk4xayt3t4u9watah405ve)]

Confirmed.

Crash virtuoso when some operations are going on in the storage service. The main repository's parent will be set as 0, and then reset to the new virtuoso model. In the middle the other threads can access it and they assert cause the parent of the model = 0.

This can probably be fixed with a mutex. I'm not sure exactly how to go about it.

[Me-ngeefk4xayt3t4u9watah405ve (me-ngeefk4xayt3t4u9watah405ve)]

Git commit d93cb74cb99936ed1edd4a10f6d6b05fa6678c7c by Vishesh Handa.
Committed on 11/03/2013 at 19:45.
Pushed by vhanda into branch 'KDE/4.10'.

Repository: Never set the parent to 0

Use a dummy model instead. Setting the parent to 0 can cause a crash
when some other threads are using the model.
FIXED-IN: 4.10.2

M +3 -1 services/storage/repository.cpp
M +3 -0 services/storage/repository.h

http://commits.kde.org/nepomuk-core/d93cb74cb99936ed1edd4a10f6d6b05fa6678c7c