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 2C32DC43441 for ; Sat, 10 Nov 2018 00:38:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E40742081C for ; Sat, 10 Nov 2018 00:38:42 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org E40742081C 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 S1728502AbeKJKVp (ORCPT ); Sat, 10 Nov 2018 05:21:45 -0500 Received: from terminus.zytor.com ([198.137.202.136]:52767 "EHLO mail.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728082AbeKJKVo (ORCPT ); Sat, 10 Nov 2018 05:21:44 -0500 Received: from hanvin-mobl2.amr.corp.intel.com ([192.55.54.40]) (authenticated bits=0) by mail.zytor.com (8.15.2/8.15.2) with ESMTPSA id wAA0cJnf2580330 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128 verify=NO); Fri, 9 Nov 2018 16:38:21 -0800 Subject: Re: PLEASE REVERT URGENTLY: Re: [PATCH v5 2/3] x86/boot: add acpi rsdp address to setup_header From: "H. Peter Anvin" To: Juergen Gross , linux-kernel@vger.kernel.org, xen-devel@lists.xenproject.org, x86@kernel.org, linux-doc@vger.kernel.org Cc: tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, corbet@lwn.net, boris.ostrovsky@oracle.com References: <20181010061456.22238-1-jgross@suse.com> <20181010061456.22238-3-jgross@suse.com> Message-ID: <7cede814-a441-05b6-10aa-5713da8ad843@zytor.com> Date: Fri, 9 Nov 2018 16:38:15 -0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.3.0 MIME-Version: 1.0 In-Reply-To: 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 One more aspect on this patchset: when CONFIG_ACPI_TABLE_UPGRADE was inroduced, it was seen as a security problem and disabled by default (unlike for device tree, where feeding entries from the boot loader is standard operating procedure.) Thus functionally makes that possible to bypass that prohibition. Are we giving up that battle, or should this also be conditionalized and default to off (presumably with Xen requiring it)? -hpa