From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757672AbYJETMA (ORCPT ); Sun, 5 Oct 2008 15:12:00 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1757434AbYJETLa (ORCPT ); Sun, 5 Oct 2008 15:11:30 -0400 Received: from earthlight.etchedpixels.co.uk ([81.2.110.250]:40050 "EHLO lxorguk.ukuu.org.uk" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1757130AbYJETL3 (ORCPT ); Sun, 5 Oct 2008 15:11:29 -0400 Date: Sun, 5 Oct 2008 20:10:56 +0100 From: Alan Cox To: "Vegard Nossum" Cc: "Ingo Molnar" , "Pekka Enberg" , linux-kernel@vger.kernel.org Subject: Re: [PATCH -tip] kmemcheck: fix crash in PnP BIOS calls Message-ID: <20081005201056.5b9b2f53@lxorguk.ukuu.org.uk> In-Reply-To: <19f34abd0810051204u241659b4j6a9ef2ab3616d3fc@mail.gmail.com> References: <20081005172504.GB24825@localhost.localdomain> <20081005191555.5715da29@lxorguk.ukuu.org.uk> <19f34abd0810051204u241659b4j6a9ef2ab3616d3fc@mail.gmail.com> X-Mailer: Claws Mail 3.5.0 (GTK+ 2.12.12; x86_64-redhat-linux-gnu) Organization: Red Hat UK Cyf., Amberley Place, 107-111 Peascod Street, Windsor, Berkshire, SL4 1TE, Y Deyrnas Gyfunol. Cofrestrwyd yng Nghymru a Lloegr o'r rhif cofrestru 3798903 Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > catch those reads/writes just fine. I'm not sure if the BIOS code can > change segments (it would need to switch LDT/GDTs, I think), and even It can do so if it wants as far as I can tell > if it did, I find it unlikely that it would directly access kernel > memory using these new segment registers. Do you happen to know of any > such cases? No. The code either seems to be very simple or just be an SMM trap in the BIOSes I've seen