Messages in this thread Patch in this message | | | From | Vlastimil Babka <> | Subject | [RFC 1/4] mm, page_alloc: fix check for NULL preferred_zone | Date | Tue, 17 Jan 2017 23:16:07 +0100 |
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Since commit c33d6c06f60f ("mm, page_alloc: avoid looking up the first zone in a zonelist twice") we have a wrong check for NULL preferred_zone, which can theoretically happen due to concurrent cpuset modification. We check the zoneref pointer which is never NULL and we should check the zone pointer.
Fixes: c33d6c06f60f ("mm, page_alloc: avoid looking up the first zone in a zonelist twice") Signed-off-by: Vlastimil Babka <vbabka@suse.cz> --- mm/page_alloc.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 34ada718ef47..593a11d8bc6b 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -3763,7 +3763,7 @@ __alloc_pages_nodemask(gfp_t gfp_mask, unsigned int order, */ ac.preferred_zoneref = first_zones_zonelist(ac.zonelist, ac.high_zoneidx, ac.nodemask); - if (!ac.preferred_zoneref) { + if (!ac.preferred_zoneref->zone) { page = NULL; goto no_zone; } -- 2.11.0
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