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=-8.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,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 D03CCC432C2 for ; Wed, 25 Sep 2019 13:07:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id AC01620640 for ; Wed, 25 Sep 2019 13:07:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2406058AbfIYNHf (ORCPT ); Wed, 25 Sep 2019 09:07:35 -0400 Received: from mga09.intel.com ([134.134.136.24]:43240 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2405791AbfIYNHf (ORCPT ); Wed, 25 Sep 2019 09:07:35 -0400 X-Amp-Result: UNKNOWN X-Amp-Original-Verdict: FILE UNKNOWN X-Amp-File-Uploaded: False Received: from fmsmga006.fm.intel.com ([10.253.24.20]) by orsmga102.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 25 Sep 2019 06:07:34 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.64,548,1559545200"; d="scan'208";a="390203184" Received: from smile.fi.intel.com (HELO smile) ([10.237.68.40]) by fmsmga006.fm.intel.com with ESMTP; 25 Sep 2019 06:07:32 -0700 Received: from andy by smile with local (Exim 4.92.1) (envelope-from ) id 1iD711-0004jE-Em; Wed, 25 Sep 2019 16:07:31 +0300 Date: Wed, 25 Sep 2019 16:07:31 +0300 From: Andy Shevchenko To: Dan Carpenter Cc: Greg Kroah-Hartman , tglx@linutronix.de, Enrico Weigelt , Kate Stewart , linux-mm@kvack.org, linux-kernel@vger.kernel.org, kernel-janitors@vger.kernel.org Subject: Re: [PATCH] mm, vmpressure: Fix a signedness bug in vmpressure_register_event() Message-ID: <20190925130731.GL5933@smile.fi.intel.com> References: <20190925110449.GO3264@mwanda> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190925110449.GO3264@mwanda> Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Sep 25, 2019 at 02:04:49PM +0300, Dan Carpenter wrote: > The "mode" and "level" variables are enums and in this context GCC will > treat them as unsigned ints so the error handling is never triggered. > > I also removed the bogus initializer because it isn't required any more > and it's sort of confusing. > Indeed, assembly code is different. Thank you for catching this! Reviewed-by: Andy Shevchenko > Fixes: 3cadfa2b9497 ("mm/vmpressure.c: convert to use match_string() helper") > Signed-off-by: Dan Carpenter > --- > mm/vmpressure.c | 6 +++--- > 1 file changed, 3 insertions(+), 3 deletions(-) > > diff --git a/mm/vmpressure.c b/mm/vmpressure.c > index f3b50811497a..fe077500cf20 100644 > --- a/mm/vmpressure.c > +++ b/mm/vmpressure.c > @@ -362,7 +362,7 @@ int vmpressure_register_event(struct mem_cgroup *memcg, > struct vmpressure *vmpr = memcg_to_vmpressure(memcg); > struct vmpressure_event *ev; > enum vmpressure_modes mode = VMPRESSURE_NO_PASSTHROUGH; > - enum vmpressure_levels level = -1; > + enum vmpressure_levels level; > char *spec, *spec_orig; > char *token; > int ret = 0; > @@ -376,7 +376,7 @@ int vmpressure_register_event(struct mem_cgroup *memcg, > /* Find required level */ > token = strsep(&spec, ","); > level = match_string(vmpressure_str_levels, VMPRESSURE_NUM_LEVELS, token); > - if (level < 0) { > + if ((int)level < 0) { > ret = level; > goto out; > } > @@ -385,7 +385,7 @@ int vmpressure_register_event(struct mem_cgroup *memcg, > token = strsep(&spec, ","); > if (token) { > mode = match_string(vmpressure_str_modes, VMPRESSURE_NUM_MODES, token); > - if (mode < 0) { > + if ((int)mode < 0) { > ret = mode; > goto out; > } > -- > 2.20.1 > -- With Best Regards, Andy Shevchenko