From: Andrea Arcangeli <aarcange@redhat.com>
Date: Thu, 17 Mar 2011 23:16:35 +0000 (+0100)
Subject: mm: PageBuddy and mapcount robustness
X-Git-Tag: v2.6.39-rc1~453
X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=ef2b4b95a63a1d23958dcb99eb2c6898eddc87d0;p=pandora-kernel.git

mm: PageBuddy and mapcount robustness

Change the _mapcount value indicating PageBuddy from -2 to -128 for
more robusteness against page_mapcount() undeflows.

Use reset_page_mapcount instead of __ClearPageBuddy in bad_page to
ignore the previous retval of PageBuddy().

Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Reported-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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