From patchwork Sat Oct 17 02:11:51 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Shijie Luo X-Patchwork-Id: 11842505 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 6A36E16BC for ; Sat, 17 Oct 2020 02:12:25 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 8985F2072D for ; Sat, 17 Oct 2020 02:12:23 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 8985F2072D Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=huawei.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 7C0056B005D; Fri, 16 Oct 2020 22:12:22 -0400 (EDT) Delivered-To: linux-mm-outgoing@kvack.org Received: by kanga.kvack.org (Postfix, from userid 40) id 74A016B0062; Fri, 16 Oct 2020 22:12:22 -0400 (EDT) X-Original-To: int-list-linux-mm@kvack.org X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 5C3356B0068; Fri, 16 Oct 2020 22:12:22 -0400 (EDT) X-Original-To: linux-mm@kvack.org X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0215.hostedemail.com [216.40.44.215]) by kanga.kvack.org (Postfix) with ESMTP id 1E9DC6B005D for ; Fri, 16 Oct 2020 22:12:22 -0400 (EDT) Received: from smtpin02.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with ESMTP id A89BD181AEF1E for ; Sat, 17 Oct 2020 02:12:21 +0000 (UTC) X-FDA: 77379792882.02.debt50_2102f0427222 Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin02.hostedemail.com (Postfix) with ESMTP id 832D41026097E for ; Sat, 17 Oct 2020 02:12:21 +0000 (UTC) X-Spam-Summary: 1,0,0,,d41d8cd98f00b204,luoshijie1@huawei.com,,RULES_HIT:30012:30054:30070,0,RBL:45.249.212.190:@huawei.com:.lbl8.mailshell.net-62.18.2.100 64.95.201.95;04ygy61q159946h9abqqx7j3mq75mypwmgr3ckb35dh7sfy7mw8ohuabo8w3e7g.3p38d15sbpndecrsu5nbyg49zu65xxxfwrx167kfpg19ur1wzpa8yekci77ez8j.1-lbl8.mailshell.net-223.238.255.100,CacheIP:none,Bayesian:0.5,0.5,0.5,Netcheck:none,DomainCache:0,MSF:not bulk,SPF:fp,MSBL:0,DNSBL:neutral,Custom_rules:0:0:0,LFtime:24,LUA_SUMMARY:none X-HE-Tag: debt50_2102f0427222 X-Filterd-Recvd-Size: 2504 Received: from huawei.com (szxga04-in.huawei.com [45.249.212.190]) by imf21.hostedemail.com (Postfix) with ESMTP for ; Sat, 17 Oct 2020 02:12:20 +0000 (UTC) Received: from DGGEMS404-HUB.china.huawei.com (unknown [172.30.72.58]) by Forcepoint Email with ESMTP id 28753F2EBE1BB435542E; Sat, 17 Oct 2020 10:12:16 +0800 (CST) Received: from huawei.com (10.175.104.175) by DGGEMS404-HUB.china.huawei.com (10.3.19.204) with Microsoft SMTP Server id 14.3.487.0; Sat, 17 Oct 2020 10:12:07 +0800 From: Shijie Luo To: CC: , , , , , , Subject: [PATCH V2] mm: fix potential pte_unmap_unlock pte error Date: Fri, 16 Oct 2020 22:11:51 -0400 Message-ID: <20201017021151.28104-1-luoshijie1@huawei.com> X-Mailer: git-send-email 2.19.1 MIME-Version: 1.0 X-Originating-IP: [10.175.104.175] X-CFilter-Loop: Reflected X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: When flags don't have MPOL_MF_MOVE or MPOL_MF_MOVE_ALL bits, code breaks and passing origin pte - 1 to pte_unmap_unlock seems like not a good idea. Signed-off-by: Shijie Luo Signed-off-by: Michal Hocko Signed-off-by: Miaohe Lin --- mm/mempolicy.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/mm/mempolicy.c b/mm/mempolicy.c index 3fde772ef5ef..3ca4898f3f24 100644 --- a/mm/mempolicy.c +++ b/mm/mempolicy.c @@ -525,7 +525,7 @@ static int queue_pages_pte_range(pmd_t *pmd, unsigned long addr, unsigned long flags = qp->flags; int ret; bool has_unmovable = false; - pte_t *pte; + pte_t *pte, *mapped_pte; spinlock_t *ptl; ptl = pmd_trans_huge_lock(pmd, vma); @@ -539,7 +539,7 @@ static int queue_pages_pte_range(pmd_t *pmd, unsigned long addr, if (pmd_trans_unstable(pmd)) return 0; - pte = pte_offset_map_lock(walk->mm, pmd, addr, &ptl); + mapped_pte = pte = pte_offset_map_lock(walk->mm, pmd, addr, &ptl); for (; addr != end; pte++, addr += PAGE_SIZE) { if (!pte_present(*pte)) continue; @@ -571,7 +571,7 @@ static int queue_pages_pte_range(pmd_t *pmd, unsigned long addr, } else break; } - pte_unmap_unlock(pte - 1, ptl); + pte_unmap_unlock(mapped_pte, ptl); cond_resched(); if (has_unmovable)