[Qemu-devel] audio segfault in qemu-kvm-0.11.0

[Qemu-devel] audio segfault in qemu-kvm-0.11.0

[Mark McLoughlin]

Hi,

Any ideas on this segfault a Fedora 12 user (Gene, cc-ed) is seeing?

Thread 1 (Thread 2849):
#0  0x00007f25fcd10f70 in memset () from /lib64/libc.so.6
No symbol table info available.
#1  0x00000000004babc6 in audio_capture_mix_and_clear (samples=-1099358712, 
    rpos=<value optimized out>, hw=<value optimized out>) at audio/audio.c:1290
        n = -1099358712
#2  audio_run_out (samples=-1099358712, rpos=<value optimized out>, 
    hw=<value optimized out>) at audio/audio.c:1354
        live = <value optimized out>
        free = <value optimized out>
        nb_live = 1
---Type <return> to continue, or q <return> to quit---
        cleanup_required = <value optimized out>
        played = <value optimized out>
        hw = <value optimized out>
        sw = <value optimized out>
#3  audio_timer (samples=-1099358712, rpos=<value optimized out>, 
    hw=<value optimized out>) at audio/audio.c:1482
        s = 0xbb6a20
#4  0x000000000040a82a in qemu_run_timers (current_time=<value optimized out>, 
    ptimer_head=0x8322b8) at /usr/src/debug/qemu-kvm-0.11.0/vl.c:1036
        ts = <value optimized out>

Full details here:

  https://bugzilla.redhat.com/528754

and backtrace here:

  https://bugzilla.redhat.com/attachment.cgi?id=365541

Thanks,
Mark.

[Qemu-devel] Re: audio segfault in qemu-kvm-0.11.0

[malc]

On Fri, 23 Oct 2009, Mark McLoughlin wrote:

> Hi,
> 
> Any ideas on this segfault a Fedora 12 user (Gene, cc-ed) is seeing?
> 
> Thread 1 (Thread 2849):
> #0  0x00007f25fcd10f70 in memset () from /lib64/libc.so.6
> No symbol table info available.
> #1  0x00000000004babc6 in audio_capture_mix_and_clear (samples=-1099358712, 
>     rpos=<value optimized out>, hw=<value optimized out>) at audio/audio.c:1290
>         n = -1099358712
> #2  audio_run_out (samples=-1099358712, rpos=<value optimized out>, 
>     hw=<value optimized out>) at audio/audio.c:1354

I don't even know what this is, there's no audio_run_out at 1354
furthermore signature is completely different..

In any case, this backtrace is useless, everything is optimized out.

>         live = <value optimized out>
>         free = <value optimized out>
>         nb_live = 1
> ---Type <return> to continue, or q <return> to quit---
>         cleanup_required = <value optimized out>
>         played = <value optimized out>
>         hw = <value optimized out>
>         sw = <value optimized out>
> #3  audio_timer (samples=-1099358712, rpos=<value optimized out>, 
>     hw=<value optimized out>) at audio/audio.c:1482
>         s = 0xbb6a20
> #4  0x000000000040a82a in qemu_run_timers (current_time=<value optimized out>, 
>     ptimer_head=0x8322b8) at /usr/src/debug/qemu-kvm-0.11.0/vl.c:1036
>         ts = <value optimized out>
> 
> Full details here:
> 
>   https://bugzilla.redhat.com/528754
> 
> and backtrace here:
> 
>   https://bugzilla.redhat.com/attachment.cgi?id=365541

Summary: No idea.

-- 
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Re: [Qemu-devel] Re: audio segfault in qemu-kvm-0.11.0

[malc]

On Fri, 23 Oct 2009, malc wrote:

> On Fri, 23 Oct 2009, Mark McLoughlin wrote:
> 
> > Hi,
> > 
> > Any ideas on this segfault a Fedora 12 user (Gene, cc-ed) is seeing?

[..snip..]

> 
> Summary: No idea.
> 

FWIW, there's no information whatosever about what audio hardware was
built and enabled, what sound system was used on the host/guest the
report is devoid of any useful information (given the state of the
backtrace)

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Re: [Qemu-devel] Re: audio segfault in qemu-kvm-0.11.0

[Mark McLoughlin]

On Fri, 2009-10-23 at 17:41 +0400, malc wrote:
> On Fri, 23 Oct 2009, malc wrote:
> 
> > On Fri, 23 Oct 2009, Mark McLoughlin wrote:
> > 
> > > Hi,
> > > 
> > > Any ideas on this segfault a Fedora 12 user (Gene, cc-ed) is seeing?
> 
> [..snip..]
> 
> > 
> > Summary: No idea.
> > 
> 
> FWIW, there's no information whatosever about what audio hardware was
> built and enabled, what sound system was used on the host/guest the
> report is devoid of any useful information (given the state of the
> backtrace)

That's fine, we'd only be delighted to provide some more info.

Our tree is at http://repo.or.cz/w/qemu-kvm/fedora.git

It's based off the stable-0.11 branch

Code is:

        if (played) {
            hw->ts_helper += played;
            audio_capture_mix_and_clear (hw, prev_rpos, played);
        }

If it would help you, I could ask Gene to reproduce with a -O0 build

Built with --audio-drv-list=pa,sdl,alsa,oss

Command line was:

  QEMU_AUDIO_DRV=none qemu-kvm ... -soundhw es1370

Not a lot of info on exactly what the guest is doing with sound, only
that they are Fedora 11 or Fedora 12 guests

Thanks,
Mark.

Re: [Qemu-devel] Re: audio segfault in qemu-kvm-0.11.0

[malc]

On Fri, 23 Oct 2009, Mark McLoughlin wrote:

> On Fri, 2009-10-23 at 17:41 +0400, malc wrote:
> > On Fri, 23 Oct 2009, malc wrote:
> > 
> > > On Fri, 23 Oct 2009, Mark McLoughlin wrote:
> > > 
> > > > Hi,
> > > > 
> > > > Any ideas on this segfault a Fedora 12 user (Gene, cc-ed) is seeing?
> > 
> > [..snip..]
> > 
> > > 
> > > Summary: No idea.
> > > 
> > 
> > FWIW, there's no information whatosever about what audio hardware was
> > built and enabled, what sound system was used on the host/guest the
> > report is devoid of any useful information (given the state of the
> > backtrace)
> 
> That's fine, we'd only be delighted to provide some more info.
> 
> Our tree is at http://repo.or.cz/w/qemu-kvm/fedora.git
>
> 
> It's based off the stable-0.11 branch
> 
> Code is:
> 
>         if (played) {
>             hw->ts_helper += played;
>             audio_capture_mix_and_clear (hw, prev_rpos, played);
>         }
> 
> If it would help you, I could ask Gene to reproduce with a -O0 build

Yes, that'd be nice.
 
> Built with --audio-drv-list=pa,sdl,alsa,oss
> 
> Command line was:
> 
>   QEMU_AUDIO_DRV=none qemu-kvm ... -soundhw es1370
> 
> Not a lot of info on exactly what the guest is doing with sound, only
> that they are Fedora 11 or Fedora 12 guests

Can Gene try to reproduce it with plain QEMU?

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Re: [Qemu-devel] Re: audio segfault in qemu-kvm-0.11.0

[Gene Czarcinski]

On Friday 23 October 2009 10:29:44 malc wrote:
> On Fri, 23 Oct 2009, Mark McLoughlin wrote:
> > On Fri, 2009-10-23 at 17:41 +0400, malc wrote:
> > > On Fri, 23 Oct 2009, malc wrote:
> > > > On Fri, 23 Oct 2009, Mark McLoughlin wrote:
> > > > > Hi,
> > > > >
> > > > > Any ideas on this segfault a Fedora 12 user (Gene, cc-ed) is
> > > > > seeing?
> > >
> > > [..snip..]
> > >
> > > > Summary: No idea.
> > >
> > > FWIW, there's no information whatosever about what audio hardware was
> > > built and enabled, what sound system was used on the host/guest the
> > > report is devoid of any useful information (given the state of the
> > > backtrace)
> >
> > That's fine, we'd only be delighted to provide some more info.
> >
> > Our tree is at http://repo.or.cz/w/qemu-kvm/fedora.git
> >
> >
> > It's based off the stable-0.11 branch
> >
> > Code is:
> >
> >         if (played) {
> >             hw->ts_helper += played;
> >             audio_capture_mix_and_clear (hw, prev_rpos, played);
> >         }
> >
> > If it would help you, I could ask Gene to reproduce with a -O0 build
> 
> Yes, that'd be nice.
> 
> > Built with --audio-drv-list=pa,sdl,alsa,oss
> >
> > Command line was:
> >
> >   QEMU_AUDIO_DRV=none qemu-kvm ... -soundhw es1370
> >
> > Not a lot of info on exactly what the guest is doing with sound, only
> > that they are Fedora 11 or Fedora 12 guests
> 
> Can Gene try to reproduce it with plain QEMU?
> 

The real sound hardware should not be relevant since qemu-kvm current does not 
support sound and "has it disabled" even if, by default, there is an ES1370 
virtual device defined.

Nevertheless, the real hardware is (ASUS M4A78 PRO mobo):
00:14.2 Audio device: ATI Technologies Inc SBx00 Azalia (Intel HDA)
	Subsystem: ASUSTeK Computer Inc. Device 8346
	Flags: bus master, slow devsel, latency 64, IRQ 16
	Memory at fbbf4000 (64-bit, non-prefetchable) [size=16K]
	Capabilities: <access denied>
	Kernel driver in use: HDA Intel
	Kernel modules: snd-hda-intel
01:05.1 Audio device: ATI Technologies Inc RS780 Azalia controller
	Subsystem: ASUSTeK Computer Inc. Device 82f1
	Flags: bus master, fast devsel, latency 0, IRQ 19
	Memory at fbdfc000 (32-bit, non-prefetchable) [size=16K]
	Capabilities: <access denied>
	Kernel driver in use: HDA Intel
	Kernel modules: snd-hda-intel

Can I reproduce the problem with qemu only (no kvm) ... If I could reproduce 
the problem at all, then maybe.  I have no idea what causes the problem.

All occurrences of the problem were on a previous install with 
qemu-kvm-0.11.0-6.fc12.x86_64.

I am currently running F12-Beta with qemu-kvm-0.11.0-7.fc12.x86_64 but still 
have the "old" system "just a re-boot away".

At the time I was running (most likely) two guests ... an F11 and an F12 and 
the guest had been running for some time (the crash did not occur immediately 
or soon after guest start).  I was certainly doing nothing with respect to 
sound since, as far as I was concerned, it did not work.

I had five occurrences of qemu-kvm segfault (according to grep'ing 
/var/log/messages* between 6 October and 13 October and an addition occurrence 
on 19 October ... all with qemu-kvm "-6".

As far as I can tell, I only have abrt data from the 19 October occurrence.

If this was a problem which I could cause "on demand", this situation may be 
different ... but I don't.  I have not had this problem occur on my fresh 
install of F12-Beta.

I can bring up q qemu guest and "let it sit" but I am not sure what to do to 
cause the problem.

Comments?

Gene

Re: [Qemu-devel] Re: audio segfault in qemu-kvm-0.11.0

[malc]

On Fri, 23 Oct 2009, Gene Czarcinski wrote:

> 
> The real sound hardware should not be relevant since qemu-kvm current does not 
> support sound and "has it disabled" even if, by default, there is an ES1370 
> virtual device defined.

I don't know anything about qemu-kvm and mysterious ways it walks (by
having audio stuff compiled in and yet somehow disabled)

Nor do i quite frankly understand why -soundhw es1370 was specified on
the command line.

[..snip..]

> 
> Can I reproduce the problem with qemu only (no kvm) ... If I could reproduce 
> the problem at all, then maybe.  I have no idea what causes the problem.
> 
> All occurrences of the problem were on a previous install with 
> qemu-kvm-0.11.0-6.fc12.x86_64.
> 
> I am currently running F12-Beta with qemu-kvm-0.11.0-7.fc12.x86_64 but still 
> have the "old" system "just a re-boot away".
> 
> At the time I was running (most likely) two guests ... an F11 and an F12 and 
> the guest had been running for some time (the crash did not occur immediately 
> or soon after guest start).  I was certainly doing nothing with respect to 
> sound since, as far as I was concerned, it did not work.
> 
> I had five occurrences of qemu-kvm segfault (according to grep'ing 
> /var/log/messages* between 6 October and 13 October and an addition occurrence 
> on 19 October ... all with qemu-kvm "-6".
> 
> As far as I can tell, I only have abrt data from the 19 October occurrence.
> 
> If this was a problem which I could cause "on demand", this situation may be 
> different ... but I don't.  I have not had this problem occur on my fresh 
> install of F12-Beta.
> 
> I can bring up q qemu guest and "let it sit" but I am not sure what to do to 
> cause the problem.
> 
> Comments?

Basically this - i've never seen this problem, nor to the best of my
knowledge anyone else, the only way to understand what's going on is
for you to try to reproduce it capture a backtrace, preferably with
vanilla qemu, and in having optimizations disabled.

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