[lxc-devel] segfault on shutdown if containers running

[Daniel Lezcano]

Adam Majer wrote:
> Cedric Le Goater wrote:
>> On 06/29/2009 02:47 AM, Adam Majer wrote:
>>> Daniel Lezcano wrote:
>>>>> Is this a known problem? If not, I'll provide the backtrace.
>>>> Yes, please, maybe I am missing something but I was not able to
>>>> reproduce it.
>>> I see to be failing at being able to safe this segfault. The computer
>>> has no serial port so I've been trying to get netconsole to work, and it
>>> does, but the entire OOPS is only visible on local console, not
>>> transmitted. Only part of the oops is transmitted :(
>>>
>>>
>>> [  635.526580] BUG: unable to handle kernel NULL pointer dereference at
>>> 000000000000009c
>>> [  635.526692] IP: [<ffffffff803b26f1>] tty_open+0x1e6/0x411
>>> [  635.526775] PGD 13dd44067 PUD 1379d5067 PMD 0
>>> [  635.526905] Oops: 0000 [#1] SMP
>>> [  635.526999] last sysfs file: /sys/devices/virtual/net/lo/operstate
>>> [  635.527045] CPU 1
>>> [  635.527110] Modules linked in: netconsole configfs veth nvidia(P)
>>> binfmt_misc powernow_k8 cpufreq_powersave cpufreq_conservative
>>> cpufreq_stats cpufreq_userspace tun bridge stp ext2 mbcache it87
>>> hwmon_vid loop firewire_sbp2 snd_hda_codec_analog snd_hda_intel
>>> snd_hda_codec snd_hwdep snd_pcm_oss snd_mixer_oss snd_pcm snd_seq_midi
>>> snd_rawmidi snd_seq_midi_event snd_seq snd_timer snd_seq_device usblp
>>> k8temp i2c_nforce2 pcspkr snd evdev asus_atk0110 i2c_core soundcore
>>> snd_page_alloc button processor xfs exportfs raid1 md_mod
>>>
>>>
>>>
>>> So, I've copied the stacktrace on paper and typing it back,
>>>
>>> Process getty (pid:3940)<<<-- looks like a process in the container?
>>>
>>> chrdev_open + 0x148/0x167
>>> chrdev_open + 0x0/0x167
>>> __dentry_open + 0x148/0x260
>>> do_flip_open + 0x468/0x85a
>>> alloc_fd + ....
>>> do_sys_gen + ...
>>> system_call_fastpath + ....
>>>
>>> RIP tty_open
>> which kernel are you using ? could you run :
>>
>>     $ addr2line -e <vmlinux> ffffffff803b26f1
>>
> 
> This is a stock Debian kernel 2.6.30-1-amd64
> 
>   linux-image-2.6.30-1-amd64
> 
> Unfortunately, there is no vmlinux, only the compressed boot image.
> 
> I have also recompiled the kernel myself and the tty_open  had the same
> base address, but alas, the addr2line just returned,
> 
>   tty_io.c:0
> 
> so not much more helpful than the System.map.
> 
> - Adam
> 
> PS. The Debian kernel is compiled with,
> 
> # CONFIG_DEBUG_INFO is not set
> 
> Would setting this to yes produce a backtrace with line numbers?

Yes and maybe CONFIG_FRAME_POINTER too.

Thanks
   -- Daniel