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=-6.9 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED 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 AC2DFC65BAE for ; Thu, 13 Dec 2018 14:14:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 7A64C2086D for ; Thu, 13 Dec 2018 14:14:21 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 7A64C2086D Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728603AbeLMOOU (ORCPT ); Thu, 13 Dec 2018 09:14:20 -0500 Received: from mx1.redhat.com ([209.132.183.28]:57192 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727707AbeLMOOT (ORCPT ); Thu, 13 Dec 2018 09:14:19 -0500 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 83AFCC04BE30; Thu, 13 Dec 2018 14:14:19 +0000 (UTC) Received: from jlaw-desktop.bos.csb (dhcp-17-208.bos.redhat.com [10.18.17.208]) by smtp.corp.redhat.com (Postfix) with ESMTP id A9B3D600C5; Thu, 13 Dec 2018 14:14:18 +0000 (UTC) Subject: Re: [PATCH 2/2 V2] livepatch: handle kzalloc failure properly To: Nicholas Mc Guire , Josh Poimboeuf Cc: Jessica Yu , Jiri Kosina , Miroslav Benes , Petr Mladek , live-patching@vger.kernel.org, linux-kernel@vger.kernel.org References: <1544709956-16701-1-git-send-email-hofrat@osadl.org> <1544709956-16701-2-git-send-email-hofrat@osadl.org> From: Joe Lawrence Organization: Red Hat Message-ID: Date: Thu, 13 Dec 2018 09:14:18 -0500 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.2.0 MIME-Version: 1.0 In-Reply-To: <1544709956-16701-2-git-send-email-hofrat@osadl.org> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.31]); Thu, 13 Dec 2018 14:14:19 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 12/13/2018 09:05 AM, Nicholas Mc Guire wrote: > kzalloc() return should be checked. On dummy_alloc() failing > in kzalloc() NULL should be returned. > > Signed-off-by: Nicholas Mc Guire > --- > > Problem was located with an experimental coccinelle script > > V2: returning NULL is ok but not without cleanup - thanks to > Petr Mladek for catching this. > > Patch was compile tested with: x86_64_defconfig + FTRACE=y > FUNCTION_TRACER=y, EXPERT=y, LATENCYTOP=y, SAMPLES=y, SAMPLE_LIVEPATCH=y > (with a number of unrelated sparse warnings on symbols not being static) > > Patch is against 4.20-rc6 (localversion-next is next-20181213) > > samples/livepatch/livepatch-shadow-mod.c | 4 ++++ > 1 file changed, 4 insertions(+) > > diff --git a/samples/livepatch/livepatch-shadow-mod.c b/samples/livepatch/livepatch-shadow-mod.c > index 4c54b25..4aa8a88 100644 > --- a/samples/livepatch/livepatch-shadow-mod.c > +++ b/samples/livepatch/livepatch-shadow-mod.c > @@ -118,6 +118,10 @@ noinline struct dummy *dummy_alloc(void) > > /* Oops, forgot to save leak! */ > leak = kzalloc(sizeof(int), GFP_KERNEL); > + if (!leak) { > + kfree(d); > + return NULL; > + } > > pr_info("%s: dummy @ %p, expires @ %lx\n", > __func__, d, d->jiffies_expire); > Hi Nicholas, Thanks for finding and fixing these up... can we either squash these two patches into a single commit or give them unique subject lines? Code looks good (including Petr's suggested fix) otherwise. -- Joe