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From: John Snow <jsnow@redhat.com>
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Date: Tue, 8 Sep 2015 10:46:27 -0400
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Subject: Re: [Qemu-devel] SLIRP segfault?
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To: Samuel Thibault <samuel.thibault@gnu.org>
Cc: Jan Kiszka <jan.kiszka@siemens.com>, qemu-devel <qemu-devel@nongnu.org>



On 09/06/2015 06:44 PM, Samuel Thibault wrote:
> Hello,
>=20
> John Snow, le Wed 02 Sep 2015 14:01:07 -0400, a =E9crit :
>> There was a downstream bug filed against qemu-kvm-2.3.1-1.fc22.x86_64
>> that appeared to segfault in the AHCI code when trying to install OSX
>> Yosemite.
>>
>> The debug output looked a little strange, so I asked for a new
>> stack-trace on an upstream build using --enable-debug to disable
>> optimizations.
>>
>> This trace came back as segfaulting in SLIRP.
>=20
> This looks even stranger.
>=20
> gdb) bt full
> #0  0x00007ffff5ff4a2f in send () from /lib64/libpthread.so.0
> No symbol table info available.
> #1  0x000055555589e06d in slirp_send (so=3D0x7fffe42cc3c0, buf=3D0x7ffe=
d85747f0, len=3D0, flags=3D0) at slirp/slirp.c:900
> No locals.
>=20
> So the segfault would be in a send call with len=3D0 ??
>=20
> I'd rather think that the segfault is actually happening in another
> thread, and
>=20
> thread apply all bt full
>=20
> should be used to get all traces.
>=20
> Samuel
>=20

Ah, of course. makes sense. relayed the info and hopefully I'll get some
nicer traces to try and make sense of.

Thanks for taking a peek.

--js