Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2993491AbXEBQ3m (ORCPT ); Wed, 2 May 2007 12:29:42 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S2993492AbXEBQ3m (ORCPT ); Wed, 2 May 2007 12:29:42 -0400 Received: from gw.goop.org ([64.81.55.164]:43388 "EHLO mail.goop.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2993491AbXEBQ3l (ORCPT ); Wed, 2 May 2007 12:29:41 -0400 Message-ID: <4638BC3E.9080708@goop.org> Date: Wed, 02 May 2007 09:28:46 -0700 From: Jeremy Fitzhardinge User-Agent: Thunderbird 1.5.0.10 (X11/20070302) MIME-Version: 1.0 To: Bill Irwin , Andrew Morton , Dan Kruchinin , linux-kernel@vger.kernel.org, Jeremy Fitzhardinge , Andi Kleen , Ingo Molnar , "Eric W. Biederman" Subject: Re: [RFC BUG?] dereference PAGE_OFFSET address (rc7-mm2) References: <20070502005140.b94500ff.akpm@linux-foundation.org> <20070502084617.GY26598@holomorphy.com> <20070502100600.GZ26598@holomorphy.com> In-Reply-To: <20070502100600.GZ26598@holomorphy.com> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 972 Lines: 22 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. > 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. J - 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/