From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S266531AbUG1X4S (ORCPT ); Wed, 28 Jul 2004 19:56:18 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S267327AbUG1X4S (ORCPT ); Wed, 28 Jul 2004 19:56:18 -0400 Received: from the-village.bc.nu ([81.2.110.252]:37531 "EHLO localhost.localdomain") by vger.kernel.org with ESMTP id S266531AbUG1X4N (ORCPT ); Wed, 28 Jul 2004 19:56:13 -0400 Subject: Re: [Fastboot] Re: Announce: dumpfs v0.01 - common RAS output API From: Alan Cox To: "Eric W. Biederman" Cc: Andrew Morton , suparna@in.ibm.com, fastboot@osdl.org, Jesse Barnes , Linux Kernel Mailing List , mbligh@aracnet.com In-Reply-To: References: <16734.1090513167@ocs3.ocs.com.au> <200407280903.37860.jbarnes@engr.sgi.com> <200407281106.17626.jbarnes@engr.sgi.com> <20040728124405.1a934bec.akpm@osdl.org> Content-Type: text/plain Content-Transfer-Encoding: 7bit Message-Id: <1091055192.31923.1.camel@localhost.localdomain> Mime-Version: 1.0 X-Mailer: Ximian Evolution 1.4.6 (1.4.6-2) Date: Wed, 28 Jul 2004 23:53:13 +0100 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Iau, 2004-07-29 at 00:11, Eric W. Biederman wrote: > If we can ensure the addresses where the new kernel will run will never > have DMA pointed at them I actually don't think so. This is why last > year I recommended building a kernel that runs at a non-default address > and finding a way to simply preload it there. We DMA into arbitary allocated pages anywhere in the memory space, so you never know where is safe other than areas preallocated during the old kernel run. Since you can just clear the master bit on each PCI device it isnt a big deal to protect against. (except a couple of devices that forget to honour it)