From 39bf5645d861cb5dc7913b183fecfc6fad033b4e Mon Sep 17 00:00:00 2001 From: Xishi Qiu Date: Fri, 1 Apr 2016 14:31:20 -0700 Subject: [PATCH] mm: fix invalid node in alloc_migrate_target() [ Upstream commit 6f25a14a7053b69917e2ebea0d31dd444cd31fd5 ] It is incorrect to use next_node to find a target node, it will return MAX_NUMNODES or invalid node. This will lead to crash in buddy system allocation. Fixes: c8721bbbdd36 ("mm: memory-hotplug: enable memory hotplug to handle hugepage") Signed-off-by: Xishi Qiu Acked-by: Vlastimil Babka Acked-by: Naoya Horiguchi Cc: Joonsoo Kim Cc: David Rientjes Cc: "Laura Abbott" Cc: Hui Zhu Cc: Wang Xiaoqiang Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Sasha Levin --- mm/page_isolation.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/mm/page_isolation.c b/mm/page_isolation.c index 303c908..4b640c2 100644 --- a/mm/page_isolation.c +++ b/mm/page_isolation.c @@ -300,11 +300,11 @@ struct page *alloc_migrate_target(struct page *page, unsigned long private, * now as a simple work-around, we use the next node for destination. */ if (PageHuge(page)) { - nodemask_t src = nodemask_of_node(page_to_nid(page)); - nodemask_t dst; - nodes_complement(dst, src); + int node = next_online_node(page_to_nid(page)); + if (node == MAX_NUMNODES) + node = first_online_node; return alloc_huge_page_node(page_hstate(compound_head(page)), - next_node(page_to_nid(page), dst)); + node); } if (PageHighMem(page)) -- 2.7.4