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=-8.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, UNPARSEABLE_RELAY,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 7E586C352A4 for ; Thu, 13 Feb 2020 03:14:40 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 0F69C20724 for ; Thu, 13 Feb 2020 03:14:39 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 0F69C20724 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.alibaba.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 919226B0501; Wed, 12 Feb 2020 22:14:39 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 8CA756B0503; Wed, 12 Feb 2020 22:14:39 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 7DE7B6B0504; Wed, 12 Feb 2020 22:14:39 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0080.hostedemail.com [216.40.44.80]) by kanga.kvack.org (Postfix) with ESMTP id 628236B0501 for ; Wed, 12 Feb 2020 22:14:39 -0500 (EST) Received: from smtpin15.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with ESMTP id 25B6C181AEF09 for ; Thu, 13 Feb 2020 03:14:39 +0000 (UTC) X-FDA: 76483636278.15.nerve53_62b0d6d5b6b43 X-HE-Tag: nerve53_62b0d6d5b6b43 X-Filterd-Recvd-Size: 2564 Received: from out30-56.freemail.mail.aliyun.com (out30-56.freemail.mail.aliyun.com [115.124.30.56]) by imf24.hostedemail.com (Postfix) with ESMTP for ; Thu, 13 Feb 2020 03:14:37 +0000 (UTC) X-Alimail-AntiSpam:AC=PASS;BC=-1|-1;BR=01201311R861e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=e01e04407;MF=yang.shi@linux.alibaba.com;NM=1;PH=DS;RN=4;SR=0;TI=SMTPD_---0TprWUQG_1581563668; Received: from US-143344MP.local(mailfrom:yang.shi@linux.alibaba.com fp:SMTPD_---0TprWUQG_1581563668) by smtp.aliyun-inc.com(127.0.0.1); Thu, 13 Feb 2020 11:14:30 +0800 Subject: Re: [PATCH 1/2] mm: vmpressure: don't need call kfree if kstrndup fails To: David Hildenbrand , akpm@linux-foundation.org Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org References: <1581398649-125989-1-git-send-email-yang.shi@linux.alibaba.com> From: Yang Shi Message-ID: <48d53caf-4b89-69c3-cf9b-47b8627db0bd@linux.alibaba.com> Date: Wed, 12 Feb 2020 19:14:27 -0800 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.12; rv:52.0) Gecko/20100101 Thunderbird/52.7.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Content-Language: en-US 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 2/12/20 3:21 AM, David Hildenbrand wrote: > On 11.02.20 06:24, Yang Shi wrote: >> When kstrndup fails (returns NULL) there is no memory is allocated by >> kmalloc, so no need to call kfree(). > "When kstrndup fails, no memory was allocated and we can exit directly." Thanks for correcting the commit log. Andrew, do you prefer I send an updated version or you would just update the patch in -mm tree? > > Reviewed-by: David Hildenbrand > >> Signed-off-by: Yang Shi >> --- >> mm/vmpressure.c | 6 ++---- >> 1 file changed, 2 insertions(+), 4 deletions(-) >> >> diff --git a/mm/vmpressure.c b/mm/vmpressure.c >> index 4bac22f..0590f00 100644 >> --- a/mm/vmpressure.c >> +++ b/mm/vmpressure.c >> @@ -371,10 +371,8 @@ int vmpressure_register_event(struct mem_cgroup *memcg, >> int ret = 0; >> >> spec_orig = spec = kstrndup(args, MAX_VMPRESSURE_ARGS_LEN, GFP_KERNEL); >> - if (!spec) { >> - ret = -ENOMEM; >> - goto out; >> - } >> + if (!spec) >> + return -ENOMEM; >> >> /* Find required level */ >> token = strsep(&spec, ","); >> >