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=-2.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,USER_AGENT_MUTT 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 DD80AC43144 for ; Sat, 23 Jun 2018 19:48:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6395624CC0 for ; Sat, 23 Jun 2018 19:48:06 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 6395624CC0 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=kernel.crashing.org 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 S1751854AbeFWTsE (ORCPT ); Sat, 23 Jun 2018 15:48:04 -0400 Received: from gate.crashing.org ([63.228.1.57]:49567 "EHLO gate.crashing.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751744AbeFWTsD (ORCPT ); Sat, 23 Jun 2018 15:48:03 -0400 Received: from gate.crashing.org (localhost.localdomain [127.0.0.1]) by gate.crashing.org (8.14.1/8.14.1) with ESMTP id w5NJlJnn007635; Sat, 23 Jun 2018 14:47:19 -0500 Received: (from segher@localhost) by gate.crashing.org (8.14.1/8.14.1/Submit) id w5NJlHFu007628; Sat, 23 Jun 2018 14:47:17 -0500 Date: Sat, 23 Jun 2018 14:47:16 -0500 From: Segher Boessenkool To: christophe leroy Cc: Mathieu Malaterre , Michael Ellerman , Yisheng Xie , Vaibhav Jain , Nicholas Piggin , linux-kernel@vger.kernel.org, Paul Mackerras , Breno Leitao , linuxppc-dev@lists.ozlabs.org Subject: Re: [PATCH] powerpc/xmon: =?utf-8?Q?avoid_?= =?utf-8?Q?warnings_about_variables_that_might_be_clobbered_by_=E2=80=98lo?= =?utf-8?B?bmdqbXDigJk=?= Message-ID: <20180623194716.GY16221@gate.crashing.org> References: <20180622192718.24242-1-malat@debian.org> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: User-Agent: Mutt/1.4.2.3i Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat, Jun 23, 2018 at 06:59:27PM +0200, christophe leroy wrote: > > > Le 22/06/2018 à 21:27, Mathieu Malaterre a écrit : > >Move initialization of variables after data definitions. This silence > >warnings treated as error with W=1: > > > > arch/powerpc/xmon/xmon.c:3389:14: error: variable ‘name’ might be > > clobbered by ‘longjmp’ or ‘vfork’ [-Werror=clobbered] > > arch/powerpc/xmon/xmon.c:3100:22: error: variable ‘tsk’ might be > > clobbered by ‘longjmp’ or ‘vfork’ [-Werror=clobbered] > > Is that an invalid warning ? No, both are correct warnings. GCC can not see which functions it only has a declaration of can call longjmp. > Otherwise, I'd expect one to fix the warning, not just cheat on GCC. Yes, the patch seems to change the code in such a way that some versions of GCC will no longer warn. Which does not make to code any more correct. Either restructure the code, or make the var non-automatic, or make it volatile. Segher