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=-2.6 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,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 80430C43381 for ; Tue, 26 Feb 2019 11:38:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4C8D02173C for ; Tue, 26 Feb 2019 11:38:25 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=alien8.de header.i=@alien8.de header.b="E7UQjXtu" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726528AbfBZLiX (ORCPT ); Tue, 26 Feb 2019 06:38:23 -0500 Received: from mail.skyhub.de ([5.9.137.197]:39452 "EHLO mail.skyhub.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726004AbfBZLiX (ORCPT ); Tue, 26 Feb 2019 06:38:23 -0500 Received: from zn.tnic (p200300EC2BCDB2001DA4ECEFA9208567.dip0.t-ipconnect.de [IPv6:2003:ec:2bcd:b200:1da4:ecef:a920:8567]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.skyhub.de (SuperMail on ZX Spectrum 128k) with ESMTPSA id 3990A1EC023E; Tue, 26 Feb 2019 12:38:21 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=alien8.de; s=dkim; t=1551181101; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:in-reply-to:in-reply-to: references:references; bh=SgzHwqbqQa6892+kC8DluEMNyaRZPOf77dEZGKPYUD0=; b=E7UQjXtu/H2Du4oouFSLoTtdDDNI4126VZVJnGw1wrcv0jHom29Pe2VNHaohFZr4QmKGhh 7Mc2yjHCS4wD4EEtNfo0EieP31DQlcKlMffswWCv4EkeGI2p9JQutcTJxXvbs/5fZLdJSA i8OMWOBYTBoeQQROcAmu8FonRWkB1gQ= Date: Tue, 26 Feb 2019 12:38:13 +0100 From: Borislav Petkov To: Peter Zijlstra Cc: "Paul E. McKenney" , Andrea Parri , linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org, Alan Stern , Will Deacon , Boqun Feng , Nicholas Piggin , David Howells , Jade Alglave , Luc Maranget , Akira Yokosawa , Daniel Lustig Subject: Re: [RFC PATCH] tools/memory-model: Remove (dep ; rfi) from ppo Message-ID: <20190226113813.GA14753@zn.tnic> References: <20190220131456.GA3215@andrea> <20190220132714.GI32494@hirez.programming.kicks-ass.net> <20190222112128.GA7213@andrea> <20190222130014.GY32494@hirez.programming.kicks-ass.net> <20190225175517.GK4072@linux.ibm.com> <20190226093009.GS32477@hirez.programming.kicks-ass.net> <20190226104551.GF32534@hirez.programming.kicks-ass.net> <20190226112133.GG32534@hirez.programming.kicks-ass.net> <20190226112521.GH32534@hirez.programming.kicks-ass.net> <20190226113008.GI32534@hirez.programming.kicks-ass.net> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20190226113008.GI32534@hirez.programming.kicks-ass.net> 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 Tue, Feb 26, 2019 at 12:30:08PM +0100, Peter Zijlstra wrote: > When I used the argc variant, gcc-8 'works', but with s/argc/1/ it is > still broken. As requested on IRC: $ gcc --version gcc (SUSE Linux) 4.8.5 Copyright (C) 2015 Free Software Foundation, Inc. This is free software; see the source for copying conditions. There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. $ cat ptr.c #include #include int y = 2, x = 1; int main (int argc, char **argv) { int *p = &x + 1; int *q = &y; printf("p=%p q=%p\n", p, q); if (!memcmp(&p, &q, sizeof(p))) { *p = 11; printf("x=%d y=%d *p=%d *q=%d\n", x, y, *p, *q); $ gcc -O2 -fno-strict-aliasing -o ptr ptr.c ; ./ptr p=0x601044 q=0x601044 x=1 y=2 *p=11 *q=2 -- Regards/Gruss, Boris. Good mailing practices for 400: avoid top-posting and trim the reply.