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=-1.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS 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 EFCDCC04EB8 for ; Tue, 4 Dec 2018 05:49:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id BD90F208A3 for ; Tue, 4 Dec 2018 05:49:49 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org BD90F208A3 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=zytor.com 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 S1726074AbeLDFts (ORCPT ); Tue, 4 Dec 2018 00:49:48 -0500 Received: from terminus.zytor.com ([198.137.202.136]:47031 "EHLO mail.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725971AbeLDFts (ORCPT ); Tue, 4 Dec 2018 00:49:48 -0500 Received: from carbon-x1.hos.anvin.org (c-24-5-245-234.hsd1.ca.comcast.net [24.5.245.234] (may be forged)) (authenticated bits=0) by mail.zytor.com (8.15.2/8.15.2) with ESMTPSA id wB45nRiu745337 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128 verify=NO); Mon, 3 Dec 2018 21:49:27 -0800 Subject: Re: [PATCH] x86/boot: clear rsdp address in boot_params for broken loaders To: Juergen Gross , linux-kernel@vger.kernel.org, x86@kernel.org Cc: sstabellini@kernel.org, tglx@linutronix.de, mingo@redhat.com, bp@alien8.de References: <20181203103811.17056-1-jgross@suse.com> <2489CC78-0410-4F0D-9D79-7905868B51BC@zytor.com> <082a6607-09f2-72d3-84f7-794c68412c66@suse.com> From: "H. Peter Anvin" Message-ID: <0917d755-3311-92a9-8fb4-c0f408633f5c@zytor.com> Date: Mon, 3 Dec 2018 21:49:22 -0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.3.1 MIME-Version: 1.0 In-Reply-To: <082a6607-09f2-72d3-84f7-794c68412c66@suse.com> 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 12/3/18 9:32 PM, Juergen Gross wrote: > > I'd like to send a followup patch doing that. And I'd like to not only > test sentinel for being non-zero, but all padding fields as well. This > should be 4.21 material, though. > No, you can't do that. That breaks backwards compatibility. -hpa