From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753822AbYKRPHj (ORCPT ); Tue, 18 Nov 2008 10:07:39 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751863AbYKRPHS (ORCPT ); Tue, 18 Nov 2008 10:07:18 -0500 Received: from mx2.mail.elte.hu ([157.181.151.9]:52453 "EHLO mx2.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753383AbYKRPHQ (ORCPT ); Tue, 18 Nov 2008 10:07:16 -0500 Date: Tue, 18 Nov 2008 16:06:59 +0100 From: Ingo Molnar To: Alan Cox Cc: "H. Peter Anvin" , Philipp Kohlbecher , Ingo Molnar , linux-kernel@vger.kernel.org Subject: Re: [PATCH] x86: alternative identifier for Phoenix BIOS Message-ID: <20081118150659.GF30358@elte.hu> References: <491EEDE8.5080508@gmx.de> <491F7D88.7080403@zytor.com> <20081116111447.23fbfe7e@lxorguk.ukuu.org.uk> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20081116111447.23fbfe7e@lxorguk.ukuu.org.uk> User-Agent: Mutt/1.5.18 (2008-05-17) X-ELTE-VirusStatus: clean X-ELTE-SpamScore: -1.5 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=-1.5 required=5.9 tests=BAYES_00,DNS_FROM_SECURITYSAGE autolearn=no SpamAssassin version=3.2.3 -1.5 BAYES_00 BODY: Bayesian spam probability is 0 to 1% [score: 0.0000] 0.0 DNS_FROM_SECURITYSAGE RBL: Envelope sender in blackholes.securitysage.com Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org * Alan Cox wrote: > On Sat, 15 Nov 2008 17:55:20 -0800 > "H. Peter Anvin" wrote: > > > Philipp Kohlbecher wrote: > > > My laptop (a Samsung X20) contains a Phoenix BIOS and would benefit from > > > patch 1e22436eba84edfec9c25e5a25d09062c4f91ca9 (x86: reserve low 64K on > > > AMI and Phoenix BIOS boxen). > > > > > > However, according to /sys/class/dmi/id/bios_vendor, the BIOS identifies > > > its vendor as "Phoenix Technologies LTD" (sans the comma). > > > > Given that AMI and Phoenix combined is something like 80% of the BIOS > > market, if not more, it might simply be easier to make it unconditional, > > or make it a whitelist instead. > > Far more useful would be to make people aware of the problem. If the > BIOS is scribbling in the low 64K of RAM not just BIOS areas, and > doing so outside of ACPI marked areas they need to fix the BIOS > ASAP. If they leave their BIOSes randomly scribbling in operating > system memory areas then as with previous (hardware related) cases > of vendors knowingly shipping corrupting equipment they'll be > building up a huge class action legal liability. > > As such making sure the vendor knows in a way they cannot deny is a > very useful activity. CONFIG_X86_CHECK_BIOS_CORRUPTION=y will do that, it prints: Corrupted low memory at 0x1000 (4096 phys) = 0x1234 Memory corruption detected in low memory < stack trace > if enough distros turn it on (at least in their debug kernels) it creates the right kind of user pressure. This debug feature to catch BIOS-generated low-memory corruption is already upstream. Ingo