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=-11.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=unavailable 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 98F77C2D0A8 for ; Mon, 28 Sep 2020 18:04:41 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 4A82A20BED for ; Mon, 28 Sep 2020 18:04:41 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 4A82A20BED Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=intel.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 90CC86B005D; Mon, 28 Sep 2020 14:04:40 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 8BCC66B0068; Mon, 28 Sep 2020 14:04:40 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 7DEB0900002; Mon, 28 Sep 2020 14:04:40 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0151.hostedemail.com [216.40.44.151]) by kanga.kvack.org (Postfix) with ESMTP id 6417B6B005D for ; Mon, 28 Sep 2020 14:04:40 -0400 (EDT) Received: from smtpin30.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay04.hostedemail.com (Postfix) with ESMTP id 271DD37F1 for ; Mon, 28 Sep 2020 18:04:40 +0000 (UTC) X-FDA: 77313245520.30.hat84_4a0cecf27183 Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin30.hostedemail.com (Postfix) with ESMTP id DD1EB180B3C94 for ; Mon, 28 Sep 2020 18:04:38 +0000 (UTC) X-HE-Tag: hat84_4a0cecf27183 X-Filterd-Recvd-Size: 2766 Received: from mga01.intel.com (mga01.intel.com [192.55.52.88]) by imf47.hostedemail.com (Postfix) with ESMTP for ; Mon, 28 Sep 2020 18:04:37 +0000 (UTC) IronPort-SDR: 6EedXow1gYlvUxfUOLwaTXoFW+2FGLdJ129r9K8sZiiEMt7ywoxj/q3GaoykY9vsHGMcfjtfyx sH6embIMirzg== X-IronPort-AV: E=McAfee;i="6000,8403,9758"; a="180196314" X-IronPort-AV: E=Sophos;i="5.77,313,1596524400"; d="scan'208";a="180196314" X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga004.jf.intel.com ([10.7.209.38]) by fmsmga101.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 28 Sep 2020 11:04:35 -0700 IronPort-SDR: tPGu1sWjNahQoAI85wJKtVMgkG/nWazOLlj63NYMTNCGfhPJYBQHsA4D26sML3CMv60sKTLiE7 rlk2KgWYB8uA== X-IronPort-AV: E=Sophos;i="5.77,313,1596524400"; d="scan'208";a="456935981" Received: from iweiny-desk2.sc.intel.com (HELO localhost) ([10.3.52.147]) by orsmga004-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 28 Sep 2020 11:04:35 -0700 Date: Mon, 28 Sep 2020 11:04:34 -0700 From: Ira Weiny To: Hui Su Cc: akpm@linux-foundation.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] mm/vmalloc.c: check the addr first Message-ID: <20200928180434.GD458519@iweiny-DESK2.sc.intel.com> References: <20200927163337.GA5472@rlk> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200927163337.GA5472@rlk> User-Agent: Mutt/1.11.1 (2018-12-01) 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 Mon, Sep 28, 2020 at 12:33:37AM +0800, Hui Su wrote: > As the comments said, if @addr is NULL, no operation > is performed, check the addr first in vfree() and > vfree_atomic() maybe a better choice. I don't see how this change helps anything. kmemleak_free() checks addr so no danger there. Also kmemleak_free() contains a pr_debug() which some might find useful. Ira > > Signed-off-by: Hui Su > --- > mm/vmalloc.c | 11 ++++++----- > 1 file changed, 6 insertions(+), 5 deletions(-) > > diff --git a/mm/vmalloc.c b/mm/vmalloc.c > index be4724b916b3..1cf50749a209 100644 > --- a/mm/vmalloc.c > +++ b/mm/vmalloc.c > @@ -2305,10 +2305,11 @@ void vfree_atomic(const void *addr) > { > BUG_ON(in_nmi()); > > - kmemleak_free(addr); > - > if (!addr) > return; > + > + kmemleak_free(addr); > + > __vfree_deferred(addr); > } > > @@ -2340,13 +2341,13 @@ void vfree(const void *addr) > { > BUG_ON(in_nmi()); > > + if (!addr) > + return; > + > kmemleak_free(addr); > > might_sleep_if(!in_interrupt()); > > - if (!addr) > - return; > - > __vfree(addr); > } > EXPORT_SYMBOL(vfree); > -- > 2.25.1 > > >