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=-5.5 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE, SPF_PASS,USER_AGENT_SANE_1 autolearn=no 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 92FDFC433E1 for ; Thu, 13 Aug 2020 13:14:03 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 583E4207DA for ; Thu, 13 Aug 2020 13:14:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726761AbgHMNOB (ORCPT ); Thu, 13 Aug 2020 09:14:01 -0400 Received: from foss.arm.com ([217.140.110.172]:54510 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726100AbgHMNN5 (ORCPT ); Thu, 13 Aug 2020 09:13:57 -0400 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 3B62F1063; Thu, 13 Aug 2020 06:13:57 -0700 (PDT) Received: from [10.0.2.15] (unknown [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 4AAAB3F6CF; Thu, 13 Aug 2020 06:13:55 -0700 (PDT) Subject: Re: [PATCH v5 06/17] sched/debug: Output SD flag names rather than their values To: Luc Van Oostenryck Cc: kernel test robot , linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, kbuild-all@lists.01.org, mingo@kernel.org, peterz@infradead.org, vincent.guittot@linaro.org, dietmar.eggemann@arm.com, morten.rasmussen@arm.com, Quentin Perret References: <20200812125300.11889-7-valentin.schneider@arm.com> <202008130025.XjiXqp1O%lkp@intel.com> <20200813120249.vdadn3nutkx3mq7y@ltop.local> From: Valentin Schneider Message-ID: <2507c6d6-eb66-504e-aba6-1333ce064da8@arm.com> Date: Thu, 13 Aug 2020 14:13:10 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.10.0 MIME-Version: 1.0 In-Reply-To: <20200813120249.vdadn3nutkx3mq7y@ltop.local> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 13/08/2020 13:02, Luc Van Oostenryck wrote: > On Wed, Aug 12, 2020 at 07:51:08PM +0100, Valentin Schneider wrote: >> On 12/08/20 17:35, kernel test robot wrote: >> >>> config: i386-randconfig-s001-20200811 (attached as .config) >>> reproduce: >>> # sparse version: v0.6.2-168-g9554805c-dirty >>> make W=1 C=1 CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__' ARCH=i386 >>> >>>>> kernel/sched/debug.c:279:17: sparse: sparse: non size-preserving pointer to integer cast >>>>> kernel/sched/debug.c:279:17: sparse: sparse: non size-preserving integer to pointer cast >>> >>> > 279 tmp += *ppos; >> >> I pretty much copied kernel/sysctl.c::_proc_do_string() and I think that's >> exactly the same types here: char* buffer incremented by loff_t offset. It >> does look fine to me, but I can't really parse that warning. > > The warnings mean that there is a cast from a pointer to an integer with > a size other than the size of a pointer and the other way around. > > I's indeed the case here, on i386, where pointers are 32-bit and loff_t > is 64-bit. But yes, I agree: > 1) these messages are far from clear > 2) these casts are internal and are probably not appropriate here. > > I'll look later what can be done at sparse level. > Thanks! > Regards, > -- Luc >