From: Eric Dumazet <eric.dumazet@gmail.com>
Date: Wed, 27 Oct 2010 17:33:43 +0000 (+0200)
Subject: numa: fix slab_node(MPOL_BIND)
X-Git-Tag: v2.6.35.10~153
X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=6b4100ddcb000aab7cbb86a66361989d1e87a1c3;p=karo-tx-linux.git

numa: fix slab_node(MPOL_BIND)

commit 800416f799e0723635ac2d720ad4449917a1481c upstream.

When a node contains only HighMem memory, slab_node(MPOL_BIND)
dereferences a NULL pointer.

[ This code seems to go back all the way to commit 19770b32609b: "mm:
  filter based on a nodemask as well as a gfp_mask".  Which was back in
  April 2008, and it got merged into 2.6.26.  - Linus ]

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Christoph Lameter <cl@linux.com>
Cc: Lee Schermerhorn <lee.schermerhorn@hp.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Andi Kleen <ak@linux.intel.com>
---

diff --git a/mm/mempolicy.c b/mm/mempolicy.c
index 5bc0a96beb51..407cda2d753f 100644
--- a/mm/mempolicy.c
+++ b/mm/mempolicy.c
@@ -1576,7 +1576,7 @@ unsigned slab_node(struct mempolicy *policy)
 		(void)first_zones_zonelist(zonelist, highest_zoneidx,
 							&policy->v.nodes,
 							&zone);
-		return zone->node;
+		return zone ? zone->node : numa_node_id();
 	}
 
 	default: