Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758482Ab1FAPpb (ORCPT ); Wed, 1 Jun 2011 11:45:31 -0400 Received: from terminus.zytor.com ([198.137.202.10]:51614 "EHLO mail.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752696Ab1FAPp3 (ORCPT ); Wed, 1 Jun 2011 11:45:29 -0400 Message-ID: <4DE65E70.50302@zytor.com> Date: Wed, 01 Jun 2011 08:44:48 -0700 From: "H. Peter Anvin" User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.2.17) Gecko/20110428 Fedora/3.1.10-1.fc15 Thunderbird/3.1.10 MIME-Version: 1.0 To: Ingo Molnar CC: Dan Rosenberg , Matthew Garrett , Tony Luck , linux-kernel@vger.kernel.org, kees.cook@canonical.com, davej@redhat.com, torvalds@linux-foundation.org, adobriyan@gmail.com, eranian@google.com, penberg@kernel.org, davem@davemloft.net, Arjan van de Ven , Valdis.Kletnieks@vt.edu, Andrew Morton , pageexec@freemail.hu, Vivek Goyal Subject: Re: [RFC][PATCH] Randomize kernel base address on boot References: <1306269105.21443.20.camel@dan> <1306442367.2279.25.camel@dan> <20110531165252.GB8971@srcf.ucam.org> <4DE5360D.5070809@zytor.com> <20110531185122.GA11998@srcf.ucam.org> <1306868609.6317.25.camel@dan> <20110531195551.GC26970@elte.hu> <4DE54C66.10106@zytor.com> <20110531202712.GB28731@elte.hu> <4DE54FFF.4010500@zytor.com> <20110601061843.GA27671@elte.hu> In-Reply-To: <20110601061843.GA27671@elte.hu> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1460 Lines: 41 On 05/31/2011 11:18 PM, Ingo Molnar wrote: >> >> Older boot loaders did not know how big the kernel image was, >> therefore had no way to avoid memory space collision. That is >> fixed in boot protocol 2.10. > > But i loaded really large kernel images way back 10 years ago on > various systems and never had any problems until the default > allyesconfig hit a ~40 MB kernel image size limit ;-) > > (which limit was in the kernel, not in the bootloader) But it would have depended on the target hardware! That's the problem. > > So yes, a large kernel image "can" be an issue with old bootloaders > in some situations on weird machines but we don't really "break" them > via randomization, they were broken and fragile in some situations to > begin with. > Well, yes; and I don't think the randomization. is a signifiant problem. > It's fixed in any distro that cares and which would use our (not even > released) kernel that might one day have randomization. > > Is that a fair summary of the bootloader situation? No, because I don't think Grub is fixed in any of its flavors. -hpa -- H. Peter Anvin, Intel Open Source Technology Center I work for Intel. I don't speak on their behalf. -- 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/