From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S272676AbTHKPXH (ORCPT ); Mon, 11 Aug 2003 11:23:07 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S272686AbTHKPXH (ORCPT ); Mon, 11 Aug 2003 11:23:07 -0400 Received: from dbl.q-ag.de ([80.146.160.66]:43968 "EHLO dbl.q-ag.de") by vger.kernel.org with ESMTP id S272676AbTHKPXF (ORCPT ); Mon, 11 Aug 2003 11:23:05 -0400 Message-ID: <3F37B4B7.9010108@colorfullife.com> Date: Mon, 11 Aug 2003 17:22:31 +0200 From: Manfred Spraul User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.4) Gecko/20030701 X-Accept-Language: en-us, en MIME-Version: 1.0 To: Ingo Molnar CC: linux-kernel@vger.kernel.org, Andrew Morton , Alexander Viro Subject: Re: 4GB+DEBUG_PAGEALLOC oopses with 2.6.0-test3-mm1 References: <3F361F5E.10106@colorfullife.com> In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Ingo Molnar wrote: >(in theory it's possible that kernel-internal mounts pass in a pointer >where pointer + PAGE_SIZE is not a valid kernel address - if this happens >then we'd get a hard crash.) > > Exactly that happens. I'm running with CONFIG_PAGE_DEBUG, i.e. unallocated pages are marked as non-present in the linear mapping. Regarding the i386 trap handler: show_registers tries to hexdump the current instructions. It did a __get_user, to avoid causing a fault when %eip is invalid. Now it contains: > if ((user_mode(regs) && get_user(c, eip)) || > (!user_mode(regs) && __direct_get_user(c, eip))) { > printk(" Bad EIP value."); > break; > } I.e. it's already fixed. -- Manfred