On Sun, Apr 07, 2013 at 04:58:07AM +0000, Zhanghaoyu (A) wrote:
> >> I start a kvm VM with vnc(using the zrle protocol) connect, sometimes qemu program crashed during starting period, received signal SIGABRT.
> >> Trying about 20 times, this crash may be reproduced.
> >> I guess the cause memory corruption or double free.
> >
> > Which version of QEMU are you running?
> >
> > Please try qemu.git/master.
> >
> > Stefan
>
> I used the QEMU download from qemu.git (http://git.qemu.org/git/qemu.git).
Great, thanks! Can you please post a backtrace?
The easiest way is:
$ ulimit -c unlimited
$ qemu-system-x86_64 -enable-kvm -m 1024 ...
...crash...
$ gdb -c qemu-system-x86_64.core
(gdb) bt
Depending on how your system is configured the core file might have a
different filename but there should be a file name *core* the current
working directory after the crash.
The backtrace will make it possible to find out where the crash
occurred.
Thanks,
Stefan
On Sun, Apr 07, 2013 at 04:58:07AM +0000, Zhanghaoyu (A) wrote:
> >>> I start a kvm VM with vnc(using the zrle protocol) connect, sometimes qemu program crashed during starting period, received signal SIGABRT.
> >>> Trying about 20 times, this crash may be reproduced.
> >>> I guess the cause memory corruption or double free.
> >>
> >> Which version of QEMU are you running?
> >>
> >> Please try qemu.git/master.
> >>
> >> Stefan
> >
> >I used the QEMU download from qemu.git (http://git.qemu.org/git/qemu.git).
>
> Great, thanks! Can you please post a backtrace?
>
> The easiest way is:
>
> $ ulimit -c unlimited
> $ qemu-system-x86_64 -enable-kvm -m 1024 ...
> ...crash...
> $ gdb -c qemu-system-x86_64.core
> (gdb) bt
>
> Depending on how your system is configured the core file might have a different filename but there should be a file name *core* the current working directory
after the crash.
>
> The backtrace will make it possible to find out where the crash occurred.
>
> Thanks,
> Stefan
backtrace from core file is shown as below:
Program received signal SIGABRT, Aborted.
0x00007f32eda3dd95 in raise () from /lib64/libc.so.6
(gdb) bt
#0 0x00007f32eda3dd95 in raise () from /lib64/libc.so.6
#1 0x00007f32eda3f2ab in abort () from /lib64/libc.so.6
#2 0x00007f32eda77ece in __libc_message () from /lib64/libc.so.6
#3 0x00007f32eda7dc06 in malloc_printerr () from /lib64/libc.so.6
#4 0x00007f32eda7ecda in _int_free () from /lib64/libc.so.6
#5 0x00007f32efd3452c in free_and_trace (mem=0x7f3290000cd0) at vl.c:2880
#6 0x00007f32efd251a1 in buffer_free (buffer=0x7f32f0c82890) at ui/vnc.c:505
#7 0x00007f32efd20c56 in vnc_zrle_clear (vs=0x7f32f0c762d0)
at ui/vnc-enc-zrle.c:364
#8 0x00007f32efd26d07 in vnc_disconnect_finish (vs=0x7f32f0c762d0)
at ui/vnc.c:1050
#9 0x00007f32efd275c5 in vnc_client_read (opaque=0x7f32f0c762d0)
at ui/vnc.c:1349
#10 0x00007f32efcb397c in qemu_iohandler_poll (readfds=0x7f32f074d020,
writefds=0x7f32f074d0a0, xfds=0x7f32f074d120, ret=1) at iohandler.c:124
#11 0x00007f32efcb46e8 in main_loop_wait (nonblocking=0) at main-loop.c:417
#12 0x00007f32efd31159 in main_loop () at vl.c:2133
#13 0x00007f32efd38070 in main (argc=46, argv=0x7fff7f5df178,
envp=0x7fff7f5df2f0) at vl.c:4481
Zhang Haoyu
On Mon, Apr 08, 2013 at 12:27:06PM +0000, Zhanghaoyu (A) wrote:
> On Sun, Apr 07, 2013 at 04:58:07AM +0000, Zhanghaoyu (A) wrote:
> > >>> I start a kvm VM with vnc(using the zrle protocol) connect, sometimes qemu program crashed during starting period, received signal SIGABRT.
> > >>> Trying about 20 times, this crash may be reproduced.
> > >>> I guess the cause memory corruption or double free.
> > >>
> > >> Which version of QEMU are you running?
> > >>
> > >> Please try qemu.git/master.
> > >>
> > >> Stefan
> > >
> > >I used the QEMU download from qemu.git (http://git.qemu.org/git/qemu.git).
> >
> > Great, thanks! Can you please post a backtrace?
> >
> > The easiest way is:
> >
> > $ ulimit -c unlimited
> > $ qemu-system-x86_64 -enable-kvm -m 1024 ...
> > ...crash...
> > $ gdb -c qemu-system-x86_64.core
> > (gdb) bt
> >
> > Depending on how your system is configured the core file might have a different filename but there should be a file name *core* the current working directory
> after the crash.
> >
> > The backtrace will make it possible to find out where the crash occurred.
> >
> > Thanks,
> > Stefan
>
> backtrace from core file is shown as below:
>
> Program received signal SIGABRT, Aborted.
> 0x00007f32eda3dd95 in raise () from /lib64/libc.so.6
> (gdb) bt
> #0 0x00007f32eda3dd95 in raise () from /lib64/libc.so.6
> #1 0x00007f32eda3f2ab in abort () from /lib64/libc.so.6
> #2 0x00007f32eda77ece in __libc_message () from /lib64/libc.so.6
> #3 0x00007f32eda7dc06 in malloc_printerr () from /lib64/libc.so.6
> #4 0x00007f32eda7ecda in _int_free () from /lib64/libc.so.6
> #5 0x00007f32efd3452c in free_and_trace (mem=0x7f3290000cd0) at vl.c:2880
> #6 0x00007f32efd251a1 in buffer_free (buffer=0x7f32f0c82890) at ui/vnc.c:505
> #7 0x00007f32efd20c56 in vnc_zrle_clear (vs=0x7f32f0c762d0)
> at ui/vnc-enc-zrle.c:364
> #8 0x00007f32efd26d07 in vnc_disconnect_finish (vs=0x7f32f0c762d0)
> at ui/vnc.c:1050
> #9 0x00007f32efd275c5 in vnc_client_read (opaque=0x7f32f0c762d0)
> at ui/vnc.c:1349
> #10 0x00007f32efcb397c in qemu_iohandler_poll (readfds=0x7f32f074d020,
> writefds=0x7f32f074d0a0, xfds=0x7f32f074d120, ret=1) at iohandler.c:124
> #11 0x00007f32efcb46e8 in main_loop_wait (nonblocking=0) at main-loop.c:417
> #12 0x00007f32efd31159 in main_loop () at vl.c:2133
> #13 0x00007f32efd38070 in main (argc=46, argv=0x7fff7f5df178,
> envp=0x7fff7f5df2f0) at vl.c:4481
CCing Corentin and Gerd who are more familiar with the VNC code than me.
Stefan
On 04/11/13 11:29, Stefan Hajnoczi wrote:
> On Mon, Apr 08, 2013 at 12:27:06PM +0000, Zhanghaoyu (A) wrote:
>> On Sun, Apr 07, 2013 at 04:58:07AM +0000, Zhanghaoyu (A) wrote:
>>>>>> I start a kvm VM with vnc(using the zrle protocol) connect, sometimes qemu program crashed during starting period, received signal SIGABRT.
>>>>>> Trying about 20 times, this crash may be reproduced.
>>>>>> I guess the cause memory corruption or double free.
>>>>>
>>>>> Which version of QEMU are you running?
>>>>>
>>>>> Please try qemu.git/master.
Please try again with latest master, might be fixed meanwhile.
If it still happens pleas provide full qemu and vnc client command lines.
>> backtrace from core file is shown as below:
>>
>> Program received signal SIGABRT, Aborted.
>> #8 0x00007f32efd26d07 in vnc_disconnect_finish (vs=0x7f32f0c762d0)
>> at ui/vnc.c:1050
Do you have a vnc client connected? Do you close it?
Any errors reported by the vnc client (maybe it disconnects due to an
error in the data stream)?
cheers,
Gerd
> > On Mon, Apr 08, 2013 at 12:27:06PM +0000, Zhanghaoyu (A) wrote:
> >> On Sun, Apr 07, 2013 at 04:58:07AM +0000, Zhanghaoyu (A) wrote:
> >>>>>> I start a kvm VM with vnc(using the zrle protocol) connect, sometimes qemu program crashed during starting period, received signal SIGABRT.
> >>>>>> Trying about 20 times, this crash may be reproduced.
> >>>>>> I guess the cause memory corruption or double free.
> >>>>>
> >>>>> Which version of QEMU are you running?
> >>>>>
> >>>>> Please try qemu.git/master.
>
> Please try again with latest master, might be fixed meanwhile.
>
> If it still happens pleas provide full qemu and vnc client command lines.
>
> >> backtrace from core file is shown as below:
> >>
> >> Program received signal SIGABRT, Aborted.
>
> >> #8 0x00007f32efd26d07 in vnc_disconnect_finish (vs=0x7f32f0c762d0)
> >> at ui/vnc.c:1050
>
> Do you have a vnc client connected? Do you close it?
>
I have a vnc client connected, it was auto closed while qemu crashed.
> Any errors reported by the vnc client (maybe it disconnects due to an error in the data stream)?
>
No errors reported by the vnc client, just popup a reconnect window.
And, I have tried to fix this bug, not reproduce this crash after tried about 100 times, patch is shown as below,
--- a/ui/vnc-jobs.c 2013-04-18 20:10:07.000000000 +0800
+++ b/ui/vnc-jobs.c 2013-04-18 20:14:06.000000000 +0800
@@ -234,7 +234,6 @@ static int vnc_worker_thread_loop(VncJob
vnc_unlock_output(job->vs);
goto disconnected;
}
- vnc_unlock_output(job->vs);
/* Make a local copy of vs and switch output buffers */
vnc_async_encoding_start(job->vs, &vs);
@@ -252,6 +251,8 @@ static int vnc_worker_thread_loop(VncJob
if (job->vs->csock == -1) {
vnc_unlock_display(job->vs->vd);
+ vnc_async_encoding_end(job->vs, &vs);
+ vnc_unlock_output(job->vs);
goto disconnected;
}
@@ -269,7 +270,6 @@ static int vnc_worker_thread_loop(VncJob
vs.output.buffer[saved_offset] = (n_rectangles >> 8) & 0xFF;
vs.output.buffer[saved_offset + 1] = n_rectangles & 0xFF;
- vnc_lock_output(job->vs);
if (job->vs->csock != -1) {
buffer_reserve(&job->vs->jobs_buffer, vs.output.offset);
buffer_append(&job->vs->jobs_buffer, vs.output.buffer,
@@ -278,6 +278,8 @@ static int vnc_worker_thread_loop(VncJob
vnc_async_encoding_end(job->vs, &vs);
qemu_bh_schedule(job->vs->bh);
+ } else {
+ vnc_async_encoding_end(job->vs, &vs);
}
vnc_unlock_output(job->vs);
Thanks,
Zhang Haoyu