Re: [Bug #13941] x86 Geode issue

[Martin-Ãric Racine]

2009/8/16 Ingo Molnar <mingo@xxxxxxx>:
>
> * Martin-Ãric Racine <q-funk@xxxxxx> wrote:
>
>> On Thu, Aug 13, 2009 at 9:34 PM, Rafael J. Wysocki<rjw@xxxxxxx> wrote:
>> > On Thursday 13 August 2009, Martin-Ãric Racine wrote:
>> >> On Thu, Aug 13, 2009 at 5:54 PM, Rafael J. Wysocki<rjw@xxxxxxx> wrote:
>> >> > On Thursday 13 August 2009, Martin-Ãric Racine wrote:
>> >> >> 2009/8/13 Martin-Ãric Racine <q-funk@xxxxxx>:
>> >> >> > On Thu, Aug 13, 2009 at 12:07 PM, Ingo Molnar<mingo@xxxxxxx> wrote:
>> >> >> >> * Martin-Ãric Racine <q-funk@xxxxxx> wrote:
>> >> >> >>> Yes, this bug is still valid.
>> >> >> >>>
>> >> >> >>> Ubuntu kernel team member Leann Ogasawara and I are slowly
>> >> >> >>> bisecting our way through the changes that took place since 2.6.30
>> >> >> >>> to find the commit that introduced this regression. Please stay
>> >> >> >>> tuned.
>> >> >> >>
>> >> >> >> hm, the only outright Geode related commit was:
>> >> >> >>
>> >> >> >> Âd6c585a: x86: geode: Mark mfgpt irq IRQF_TIMER to prevent resume failure
>> >> >> >>
>> >> >> >> the jpg at:
>> >> >> >>
>> >> >> >> Âhttp://launchpadlibrarian.net/28892781/00002.jpg
>> >> >> >>
>> >> >> >> is very out of focus - but what i could decypher suggests a
>> >> >> >> pagefault crash in the VFS code, in generic_delete_inode().
>> >> >>
>> >> >> This one might be a bit better:
>> >> >>
>> >> >> http://launchpadlibrarian.net/30267494/2.6.31-5.24.jpg
>> >
>> > Hmm. ÂThis looks like a sysfs oops to my untrained eye.
>>
>> The bisect I did with Leann Ogasawara has narrowed the kernel panic
>> down to the following:
>>
>> commit f19d4a8fa6f9b6ccf54df0971c97ffcaa390b7b0
>> Author: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
>> Date: Mon Jun 8 19:50:45 2009 -0400
>>
>> Â Â add caching of ACLs in struct inode
>>
>> Â Â No helpers, no conversions yet.
>>
>> Â Â Signed-off-by: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
>
> Weird. If the functions do what their name suggests, i.e. if
> inode_init_always() is an always called constructor and if
> destroy_inode() is an unconditional destructor then this patch
> should have no functional effect on the VFS side.
>
> It increases the size of struct inode, so if you have some old
> module (built to an older version of fs.h) still around it might
> corrupt your inode data structure.
>
> Or the size change might trigger some dormant bug. It might move a
> critical inode right into the path of a pre-existing (but not
> visibly crash-triggering) data corruption.
>
> The possibilities on the 'weird bug' front are endless - the
> crash/oops itself should be turned into text, posted here and
> analyzed.

If you mean something else than the large-size snapshot of the whole
panic output that was linked earlier in this thread, I'd appreciate
instructions on how to turn that crash into text.

Martin-Ãric
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