Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752250AbcCYG5P (ORCPT ); Fri, 25 Mar 2016 02:57:15 -0400 Received: from szxga02-in.huawei.com ([119.145.14.65]:43965 "EHLO szxga02-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751875AbcCYG5O (ORCPT ); Fri, 25 Mar 2016 02:57:14 -0400 Message-ID: <56F4E104.9090505@huawei.com> Date: Fri, 25 Mar 2016 14:56:04 +0800 From: Xishi Qiu User-Agent: Mozilla/5.0 (Windows NT 6.1; rv:12.0) Gecko/20120428 Thunderbird/12.0.1 MIME-Version: 1.0 To: Andrew Morton , Vlastimil Babka , Joonsoo Kim , David Rientjes , Naoya Horiguchi , "Laura Abbott" , , CC: Xishi Qiu , Linux MM , LKML Subject: [PATCH] mm: fix invalid node in alloc_migrate_target() Content-Type: text/plain; charset="ISO-8859-1" Content-Transfer-Encoding: 7bit X-Originating-IP: [10.177.25.179] X-CFilter-Loop: Reflected X-Mirapoint-Virus-RAPID-Raw: score=unknown(0), refid=str=0001.0A020203.56F4E115.014D,ss=1,re=0.000,recu=0.000,reip=0.000,cl=1,cld=1,fgs=0, ip=0.0.0.0, so=2013-06-18 04:22:30, dmn=2013-03-21 17:37:32 X-Mirapoint-Loop-Id: c91782570e5831f8b449cf5c0f666fa3 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1015 Lines: 32 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. Signed-off-by: Xishi Qiu --- 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 92c4c36..31555b6 100644 --- a/mm/page_isolation.c +++ b/mm/page_isolation.c @@ -289,11 +289,11 @@ 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)) -- 1.8.3.1