From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1422953AbaGRTRS (ORCPT ); Fri, 18 Jul 2014 15:17:18 -0400 Received: from terminus.zytor.com ([198.137.202.10]:43008 "EHLO mail.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755373AbaGRTRR (ORCPT ); Fri, 18 Jul 2014 15:17:17 -0400 Message-ID: <53C97287.5020509@zytor.com> Date: Fri, 18 Jul 2014 12:16:23 -0700 From: "H. Peter Anvin" User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Thunderbird/24.6.0 MIME-Version: 1.0 To: Stephen Rothwell , Thomas Gleixner , Ingo Molnar , Peter Zijlstra CC: linux-next@vger.kernel.org, linux-kernel@vger.kernel.org, Andy Lutomirski , Linus Torvalds Subject: Re: linux-next: build warning after merge of the tip tree References: <20140718150005.73db8eb9@canb.auug.org.au> In-Reply-To: <20140718150005.73db8eb9@canb.auug.org.au> X-Enigmail-Version: 1.6 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 07/17/2014 10:00 PM, Stephen Rothwell wrote: > Hi all, > > After merging the tip tree, today's linux-next build (x86_64 > allmodconfig) produced these warnings: > > In file included from arch/x86/vdso/vdso2c.c:161:0: > arch/x86/vdso/vdso2c.c: In function 'main': > arch/x86/vdso/vdso2c.h:118:6: warning: assuming signed overflow > does not occur when assuming that (X + c) < X is always false > [-Wstrict-overflow] In file included from > arch/x86/vdso/vdso2c.c:165:0: arch/x86/vdso/vdso2c.h:118:6: > warning: assuming signed overflow does not occur when assuming that > (X + c) < X is always false [-Wstrict-overflow] > > Probably introduced by commit e6577a7ce99a ("x86, vdso: Move the > vvar area before the vdso text"). > This seems toxic. I always wonder if we shouldn't use -fwrapv for the kernel... -hpa