From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-11.4 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,NICE_REPLY_A, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id CDE3EC55178 for ; Fri, 23 Oct 2020 11:12:16 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 2377921D43 for ; Fri, 23 Oct 2020 11:12:15 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 2377921D43 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=suse.cz Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 306A56B005D; Fri, 23 Oct 2020 07:12:15 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 2B6676B0062; Fri, 23 Oct 2020 07:12:15 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 1A4A66B0068; Fri, 23 Oct 2020 07:12:15 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0104.hostedemail.com [216.40.44.104]) by kanga.kvack.org (Postfix) with ESMTP id E53E36B005D for ; Fri, 23 Oct 2020 07:12:14 -0400 (EDT) Received: from smtpin10.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay04.hostedemail.com (Postfix) with ESMTP id 6BCE31EE6 for ; Fri, 23 Oct 2020 11:12:14 +0000 (UTC) X-FDA: 77402926188.10.level21_4d0c7e027259 Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin10.hostedemail.com (Postfix) with ESMTP id 3F2BC16A4A9 for ; Fri, 23 Oct 2020 11:12:14 +0000 (UTC) X-HE-Tag: level21_4d0c7e027259 X-Filterd-Recvd-Size: 2052 Received: from mx2.suse.de (mx2.suse.de [195.135.220.15]) by imf17.hostedemail.com (Postfix) with ESMTP for ; Fri, 23 Oct 2020 11:12:13 +0000 (UTC) X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id 7F28CB7EE; Fri, 23 Oct 2020 11:12:12 +0000 (UTC) Subject: Re: [PATCH v2] mm/msync: exit early when the flags is an MS_ASYNC and start < vm_start To: Nikita Ermakov , linux-mm@kvack.org Cc: Andrew Morton References: <94E11FCB-AA03-490B-9F9E-2508DC8A15D1@mail.si-head.nl> <20201020205640.48257-1-sh1r4s3@mail.si-head.nl> From: Vlastimil Babka Message-ID: Date: Fri, 23 Oct 2020 13:12:11 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.3.3 MIME-Version: 1.0 In-Reply-To: <20201020205640.48257-1-sh1r4s3@mail.si-head.nl> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit 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: On 10/20/20 10:56 PM, Nikita Ermakov wrote: > If an unmapped region was found and the flag is MS_ASYNC (without > MS_INVALIDATE) there is nothing to do and the result would be always > -ENOMEM, so return immediately. > > Signed-off-by: Nikita Ermakov > --- > mm/msync.c | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/mm/msync.c b/mm/msync.c > index 69c6d2029531..ed20c3621d4c 100644 > --- a/mm/msync.c > +++ b/mm/msync.c > @@ -69,6 +69,8 @@ SYSCALL_DEFINE3(msync, unsigned long, start, size_t, len, int, flags) > goto out_unlock; > /* Here start < vma->vm_end. */ > if (start < vma->vm_start) { I hoped it would become a code comment. > + if (flags == MS_ASYNC) > + goto out_unlock; > start = vma->vm_start; > if (start >= end) > goto out_unlock; > > base-commit: 6824a8a9b4861d7df7ee132a952bdf6f84a99cb8 >