mm: bugfix: set current->reclaim_state to NULL while returning from kswapd()
authorTakamori Yamaguchi <takamori.yamaguchi@jp.sony.com>
Thu, 8 Nov 2012 23:53:39 +0000 (15:53 -0800)
committerLinus Torvalds <torvalds@linux-foundation.org>
Fri, 9 Nov 2012 05:41:47 +0000 (06:41 +0100)
commitb0a8cc58e6b9aaae3045752059e5e6260c0b94bc
tree9c699b9a9bdeeb940b2e96b4cd5325061dd28b02
parent848561d368751a1c0f679b9f045a02944506a801
mm: bugfix: set current->reclaim_state to NULL while returning from kswapd()

In kswapd(), set current->reclaim_state to NULL before returning, as
current->reclaim_state holds reference to variable on kswapd()'s stack.

In rare cases, while returning from kswapd() during memory offlining,
__free_slab() and freepages() can access the dangling pointer of
current->reclaim_state.

Signed-off-by: Takamori Yamaguchi <takamori.yamaguchi@jp.sony.com>
Signed-off-by: Aaditya Kumar <aaditya.kumar@ap.sony.com>
Acked-by: David Rientjes <rientjes@google.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
mm/vmscan.c