Messages in this thread | | | Date | Fri, 24 Feb 2012 19:01:15 +0100 (CET) | From | Jiri Kosina <> | Subject | Re: Linux 3.3-rc4 |
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On Fri, 24 Feb 2012, Linus Torvalds wrote:
> > The machine has gone through several suspend-resume cycles before this > > happened, so it might well also be some memory corruption caused by a > > random driver. > > I almost think it is, because "file->dentry" should never be NULL in a > mapping afaik. Especially as your "mapping" certainly isn't NULL (it's > in %r12, so you can see it in your register dump). > > This isn't some unusual code sequence either, so I don't see it as > some random latent bug that is just very unlikely and hard to trigger > in that code itself. > > I'll think about it, but my first reaction is "memory corruption". Do > you think you could try to run with a kernel that has SLAB debugging > and poisoning on? If it's a stale pointer dereference that has cleared > that dentry, that _might_ show it closer to the actual bug (rather > than a long time later when the NULL dereference happens).
Running DEBUG_SLAB kernel since I have first hit the bug, but nothing popped up yet. Seems undebuggable so far.
On the other hand I wouldn't blame HW for a bit-flip, as it was a clear NULL pointer (plus 0x30 offset), not a random garbage.
-- Jiri Kosina SUSE Labs
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