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=1.3 required=3.0 tests=DKIM_SIGNED,FSL_HELO_FAKE, MAILING_LIST_MULTI,SPF_PASS,T_DKIM_INVALID,URIBL_BLOCKED,USER_AGENT_MUTT 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 D6A42ECDFB3 for ; Sun, 15 Jul 2018 22:59:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 84ABF2089D for ; Sun, 15 Jul 2018 22:59:01 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="Zm5hkkrB" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 84ABF2089D Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.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 S1727191AbeGOXXX (ORCPT ); Sun, 15 Jul 2018 19:23:23 -0400 Received: from mail-wm0-f65.google.com ([74.125.82.65]:50256 "EHLO mail-wm0-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727007AbeGOXXW (ORCPT ); Sun, 15 Jul 2018 19:23:22 -0400 Received: by mail-wm0-f65.google.com with SMTP id v25-v6so13351598wmc.0 for ; Sun, 15 Jul 2018 15:58:52 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=sender:date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to:user-agent; bh=R0HTxfQLHIGBhGHQdcDuF2WSlfyWyL5x5araBZcNpdI=; b=Zm5hkkrBdIOw79lSob5l4p5Yi5AgU1vl/ATLexCeDdqCnN63D+JRgfpwvBQxPXaHJA SyorjluQ5D9zsW5E2OEK0RqLFlO5bHD3kdE0oGM5xhcKfDHA1ugi32YLFgm14J58Ntvz 79P9B/NsIg6Q3oMEmUiJzu9Ivtfor0m+bTk69AhUXdc/VTsCm1Rm7zhYnOWkHLjQr062 yR9+pThiYwmIMLLZjRM/prQGIc4wA9nwZmicKCHe/rv2qSxlDJrrqHOGAt6ZC2oxVNw/ yVdfh6ObTdqOP8+P+bsXgV5GmFxvjjBU8CLQqhP5yTLSKcC9B1M/pbHBl//Mqqubog2P DfJA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:sender:date:from:to:cc:subject:message-id :references:mime-version:content-disposition:in-reply-to:user-agent; bh=R0HTxfQLHIGBhGHQdcDuF2WSlfyWyL5x5araBZcNpdI=; b=hmMVv8okHTo8kv5dWSanFyInYr2XwL7Yqx2WAtdkuaLEPSXM6xF/e/mYx8hokxJZBz OuzekXxmPsrnhauLk9t2m4LXilpkdFVOixBzWVLWpBJHSuo8jEAFvSq0jECpSJCNxv+Q Aic2R6K3PDsoHGyAayvjdNmNUdsDAW/LPCzVFLdbNz2BOF73CDzGfJ70+Ge3WZuLzDNo yYcVHWM8ycfBrIffAMbznG1gqnUSF3TEnAYdvnk3J08Q+jxKU8v45xLWohe192nRMriL 08C3Wu5CzCrHcfbisZf0f8dtrXhE68pebajwejcxSFmL0MGVbleN9AW4qmPeZ3jlymNY IHfA== X-Gm-Message-State: AOUpUlGEPrJNxPjcm2EzNMXr/tmykDR8NGQvtD9t9YX7MR/W52ExSyDL D3xtkoZ4pGgZgchLnn4Zdto= X-Google-Smtp-Source: AAOMgpdHs6fqiw4kWcdyWnf8OU4aFtfbOfR3DCfNq2DJXSolnAeN+1Y52eSbEAsRHtjUQ3GlpeEiHQ== X-Received: by 2002:a1c:dc89:: with SMTP id t131-v6mr8916686wmg.50.1531695532003; Sun, 15 Jul 2018 15:58:52 -0700 (PDT) Received: from gmail.com (2E8B0CD5.catv.pool.telekom.hu. [46.139.12.213]) by smtp.gmail.com with ESMTPSA id e12-v6sm25530223wrt.29.2018.07.15.15.58.50 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Sun, 15 Jul 2018 15:58:51 -0700 (PDT) Date: Mon, 16 Jul 2018 00:58:49 +0200 From: Ingo Molnar To: Kees Cook Cc: Ingo Molnar , Dirk Gouders , Masahiro Yamada , Thomas Gleixner , "H. Peter Anvin" , x86@kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] x86/boot: Fix if_changed build flip/flop Message-ID: <20180715225849.GB30102@gmail.com> References: <20180715025626.GA48623@beast> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180715025626.GA48623@beast> User-Agent: Mutt/1.9.4 (2018-02-28) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org * Kees Cook wrote: > The if_changed kbuild function can only be used once per target. If not > it will effectively always trigger, flipping back and forth between the > two commands getting recorded. Instead, merge the two commands into a > single function to get stable build artifacts (i.e. .vmlinux.cmd). > > Reported-by: Dirk Gouders What actual symptoms does this bug have? I.e. it would be nice if the changelog started with such an explanation: Dirk Gouders reported that .... ... and bisected it back to: 98f78525371b ("x86/boot: Refuse to build with data relocations") The root cause of the bug is that the if_changed kbuild function ... Or something like that. Thanks, Ingo