Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2993460AbXEBQeQ (ORCPT ); Wed, 2 May 2007 12:34:16 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S2993468AbXEBQeQ (ORCPT ); Wed, 2 May 2007 12:34:16 -0400 Received: from agminet01.oracle.com ([141.146.126.228]:60023 "EHLO agminet01.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2993460AbXEBQeP (ORCPT ); Wed, 2 May 2007 12:34:15 -0400 Date: Wed, 2 May 2007 09:32:44 -0700 From: Bill Irwin To: Jeremy Fitzhardinge Cc: Bill Irwin , Andrew Morton , Dan Kruchinin , linux-kernel@vger.kernel.org, Jeremy Fitzhardinge , Andi Kleen , Ingo Molnar , "Eric W. Biederman" , wli@holomorphy.com Subject: Re: [RFC BUG?] dereference PAGE_OFFSET address (rc7-mm2) Message-ID: <20070502163244.GA26598@holomorphy.com> Mail-Followup-To: Bill Irwin , Jeremy Fitzhardinge , Andrew Morton , Dan Kruchinin , linux-kernel@vger.kernel.org, Jeremy Fitzhardinge , Andi Kleen , Ingo Molnar , "Eric W. Biederman" References: <20070502005140.b94500ff.akpm@linux-foundation.org> <20070502084617.GY26598@holomorphy.com> <20070502100600.GZ26598@holomorphy.com> <4638BC3E.9080708@goop.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4638BC3E.9080708@goop.org> User-Agent: Mutt/1.5.11 X-Brightmail-Tracker: AAAAAQAAAAI= X-Brightmail-Tracker: AAAAAQAAAAI= X-Whitelist: TRUE X-Whitelist: TRUE Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1109 Lines: 24 Bill Irwin wrote: >> Brain dump before crashing for the night: >> The patch refuses to clobber already-present pagetable entries of >> whatever origin. There are pagetables prior to this setup covering the >> address range just above PAGE_OFFSET. If this theory is correct, you >> should only be able to go a few MB above PAGE_OFFSET before encountering >> unreadable kernel memory. IIRC those pagetables are a statically >> allocated array in assembly; altering that array to set supervisor bits >> may resolve it, though it may also be freed as initmem. On Wed, May 02, 2007 at 09:28:46AM -0700, Jeremy Fitzhardinge wrote: > I think this should be fixed now. Eric made all those writes > unconditional (to fix a problem with PSE superpages not being created). > The patch is in Andi's queue. It needs verification with the testcase from this thread. -- wli - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/