Re: [Bug #13941] x86 Geode issue

Ingo Molnar
2009-08-16T21:34:07Z

* Martin-Éric Racine <q-funk-X3B1VOXEql0@public.gmane.org> wrote:

> 2009/8/16 Ingo Molnar <mingo-X9Un+BFzKDI@public.gmane.org>:
> >
> > * Martin-Éric Racine <q-funk-X3B1VOXEql0@public.gmane.org> wrote:
> >
> >> On Thu, Aug 13, 2009 at 9:34 PM, Rafael J. Wysocki<rjw-KKrjLPT3xs0@public.gmane.org> wrote:
> >> > On Thursday 13 August 2009, Martin-Éric Racine wrote:
> >> >> On Thu, Aug 13, 2009 at 5:54 PM, Rafael J. Wysocki<rjw-KKrjLPT3xs0@public.gmane.org> wrote:
> >> >> > On Thursday 13 August 2009, Martin-Éric Racine wrote:
> >> >> >> 2009/8/13 Martin-Éric Racine <q-funk-X3B1VOXEql0@public.gmane.org>:
> >> >> >> > On Thu, Aug 13, 2009 at 12:07 PM, Ingo Molnar<mingo@elte.hu> wrote:
> >> >> >> >> * Martin-Éric Racine <q-funk-X3B1VOXEql0@public.gmane.org> 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:
> >> >> >> >>
> >> >> >> >>  d6c585a: x86: geode: Mark mfgpt irq IRQF_TIMER to prevent resume failure
> >> >> >> >>
> >> >> >> >> the jpg at:
> >> >> >> >>
> >> >> >> >>  http://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.  This 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-RmSDqhL/yNMiFSDQTTA3OLVCufUGDwFn@public.gmane.org>
> >> Date: Mon Jun 8 19:50:45 2009 -0400
> >>
> >>     add caching of ACLs in struct inode
> >>
> >>     No helpers, no conversions yet.
> >>
> >>     Signed-off-by: Al Viro <viro-RmSDqhL/yNMiFSDQTTA3OLVCufUGDwFn@public.gmane.org>
> >
> > 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.

it's still a JPG - posting the transcribed oops in email text would
certainly help more folks looking over it.

(painful i know ...)

Ingo