From: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Date: Mon, 8 Oct 2012 23:33:47 +0000 (-0700)
Subject: kpageflags: fix wrong KPF_THP on non-huge compound pages
X-Git-Tag: v3.7-rc1~74^2~19
X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=7a71932d5676b7410ab64d149bad8bde6b0d8632;p=pandora-kernel.git

kpageflags: fix wrong KPF_THP on non-huge compound pages

KPF_THP can be set on non-huge compound pages (like slab pages or pages
allocated by drivers with __GFP_COMP) because PageTransCompound only
checks PG_head and PG_tail.  Obviously this is a bug and breaks user space
applications which look for thp via /proc/kpageflags.

This patch rules out setting KPF_THP wrongly by additionally checking
PageLRU on the head pages.

Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Acked-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Acked-by: David Rientjes <rientjes@google.com>
Reviewed-by: Fengguang Wu <fengguang.wu@intel.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---

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