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Date: Tue, 6 Apr 2010 12:03:15 -0700
From: Andrew Morton <akpm@linux-foundation.org>
To: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Rik van Riel <riel@redhat.com>, Minchan Kim <minchan.kim@gmail.com>,
       KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>,
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       Nick Piggin <npiggin@suse.de>, Andrea Arcangeli <aarcange@redhat.com>,
       Hugh Dickins <hugh.dickins@tiscali.co.uk>, sgunderson@bigfoot.com
Subject: Re: Ugly rmap NULL ptr deref oopsie on hibernate (was Linux
 2.6.34-rc3)
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On Tue, 6 Apr 2010 11:28:52 -0700 (PDT)
Linus Torvalds <torvalds@linux-foundation.org> wrote:

> For example, maybe some list corruption causes us to do that 
> "anon_vma_chain_link()" _twice_ on the same avc entry. So we do that 
> "list_add_tail(&avc->same_anon_vma, &anon_vma->head);" on an entry that 
> already had "same_anon_vma" on one list.

The lib/list_debug.c stuff might detect such things.  I wonder if
either Borislav or Steinar had CONFIG_DEBUG_LIST enabled?