From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751188AbdJBVo2 (ORCPT ); Mon, 2 Oct 2017 17:44:28 -0400 Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:59056 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750770AbdJBVo1 (ORCPT ); Mon, 2 Oct 2017 17:44:27 -0400 From: Reza Arbab To: Andrew Morton , =?UTF-8?q?J=C3=A9r=C3=B4me=20Glisse?= Cc: Balbir Singh , Naoya Horiguchi , Minchan Kim , Johannes Weiner , "Kirill A. Shutemov" , linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: [PATCH] mm/migrate: Fix early increment of migrate->npages Date: Mon, 2 Oct 2017 16:44:02 -0500 X-Mailer: git-send-email 1.8.3.1 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-TM-AS-GCONF: 00 x-cbid: 17100221-0004-0000-0000-0000130184C3 X-IBM-SpamModules-Scores: X-IBM-SpamModules-Versions: BY=3.00007831; HX=3.00000241; KW=3.00000007; PH=3.00000004; SC=3.00000233; SDB=6.00925592; UDB=6.00465527; IPR=6.00705791; BA=6.00005616; NDR=6.00000001; ZLA=6.00000005; ZF=6.00000009; ZB=6.00000000; ZP=6.00000000; ZH=6.00000000; ZU=6.00000002; MB=3.00017368; XFM=3.00000015; UTC=2017-10-02 21:44:06 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 17100221-0005-0000-0000-000084525958 Message-Id: <1506980642-16541-1-git-send-email-arbab@linux.vnet.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:,, definitions=2017-10-02_07:,, signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 spamscore=0 suspectscore=0 malwarescore=0 phishscore=0 adultscore=0 bulkscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1707230000 definitions=main-1710020315 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The intention here is to set the same array element in src and dst. Switch the order of these lines so that migrate->npages is only incremented after we've used it. Fixes: 8315ada7f095 ("mm/migrate: allow migrate_vma() to alloc new page on empty entry") Cc: Jérôme Glisse Signed-off-by: Reza Arbab --- mm/migrate.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/mm/migrate.c b/mm/migrate.c index dea0ceb..c4546cc 100644 --- a/mm/migrate.c +++ b/mm/migrate.c @@ -2146,8 +2146,8 @@ static int migrate_vma_collect_hole(unsigned long start, unsigned long addr; for (addr = start & PAGE_MASK; addr < end; addr += PAGE_SIZE) { - migrate->src[migrate->npages++] = MIGRATE_PFN_MIGRATE; migrate->dst[migrate->npages] = 0; + migrate->src[migrate->npages++] = MIGRATE_PFN_MIGRATE; migrate->cpages++; } -- 1.8.3.1