From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753746Ab2JDUHw (ORCPT ); Thu, 4 Oct 2012 16:07:52 -0400 Received: from g5t0009.atlanta.hp.com ([15.192.0.46]:19800 "EHLO g5t0009.atlanta.hp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751650Ab2JDUHu (ORCPT ); Thu, 4 Oct 2012 16:07:50 -0400 Message-ID: <506DEC95.8050806@hp.com> Date: Thu, 04 Oct 2012 14:07:49 -0600 From: Randy Wright Organization: Hewlett-Packard Company User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:10.0.7) Gecko/20120824 Thunderbird/10.0.7 MIME-Version: 1.0 To: Matthew Garrett CC: linux-kernel@vger.kernel.org, tmac@hp.com, hpa@zytor.com, rwright@hp.com Subject: Re: [PATCH] Fix devmem_is_allowed for below 1MB accesses for an efi machine References: In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 10/02/2012 11:20 PM, Matthew Garrett wrote: > Oh, right, got you. In that case I think we potentially need a > finer-grained check on EFI platforms - the EFI memory map is kind enough > to tell us the difference between unusable regions and io regions, and > we could avoid access to the unusable ones. I wanted to mention in this context a patch RFC I posted yesterday as a distinct thread which is visible as https://lkml.org/lkml/2012/10/3/589 with the subject: [PATCH RFC] function probe_roms accessing improper addresses on UEFI systems. While the mechanism is different from Tmac's patch (because probe_roms runs early in boot, prior to resource structure initialization) the intent of the change is the same: to prevent a machine check resulting from access to inappropriate physical addresses. I will monitor both this thread as well as my own recent RFC posting since the underlying issues are common. -- Randy Wright +1-970-898-0998