[libvirt-users] About debugging of libvirt.

[Daniel P. Berrange]

On Thu, Dec 19, 2013 at 03:09:14PM +0530, cool dharma06 wrote:
> I am newbie to this gdb debugging. now i did the bt in the debugging. In my
> side still it showing the error. Following are the stacktrace which i got.
> Kindly refer the following logs for full information:
> 
> ****
> [New Thread 0x7f8503695700 (LWP 20012)]
> 
> Program received signal SIGSEGV, Segmentation fault.
> 0x0000000000000000 in ?? ()
> (gdb) bt
> #0  0x0000000000000000 in ?? ()
> #1  0x00007f84f671281e in libxl_osevent_occurred_timeout (ctx=<optimized
> out>, for_libxl=0x7f8503bbbc38) at libxl_event.c:1039
> #2  0x00007f84f69439c7 in libxlDomainObjTimerCallback (timer=<optimized
> out>, timer_info=0x7f8503bb5930) at libxl/libxl_domain.c:216
> #3  0x00007f8502ba6f7d in virEventPollDispatchTimeouts () at
> util/vireventpoll.c:451
> #4  virEventPollRunOnce () at util/vireventpoll.c:644
> #5  0x00007f8502ba570b in virEventRunDefaultImpl () at util/virevent.c:274
> #6  0x00007f8502cda065 in virNetServerRun (srv=0x7f8503ba6ba0) at
> rpc/virnetserver.c:1112
> #7  0x00007f85036c251c in main (argc=<optimized out>, argv=<optimized out>)
> at libvirtd.c:1513
> (gdb)

In this case, that stack trace looks like it ought to be sufficient
to identify the problem - a clear NULL pointer reference. In general
though you want to capture a stack trace of all threads in a program

eg instead of 'bt', do 'thread apply all bt' next time.

Regards,
Daniel
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