From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758357Ab2KVWWW (ORCPT ); Thu, 22 Nov 2012 17:22:22 -0500 Received: from terminus.zytor.com ([198.137.202.10]:36842 "EHLO mail.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754411Ab2KVSiP (ORCPT ); Thu, 22 Nov 2012 13:38:15 -0500 Message-ID: <50AE70E7.6060204@zytor.com> Date: Thu, 22 Nov 2012 10:37:27 -0800 From: "H. Peter Anvin" User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:16.0) Gecko/20121029 Thunderbird/16.0.2 MIME-Version: 1.0 To: Yinghai Lu CC: Thomas Gleixner , Ingo Molnar , "Eric W. Biederman" , linux-kernel@vger.kernel.org, Rob Landley , Matt Fleming Subject: Re: [PATCH v3 11/12] x86, boot: add fields to support load bzImage and ramdisk high References: <1353482170-10160-1-git-send-email-yinghai@kernel.org> <1353482170-10160-12-git-send-email-yinghai@kernel.org> <50AD0CA1.8000904@zytor.com> <50AD291A.10600@zytor.com> In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 11/22/2012 10:28 AM, Yinghai Lu wrote: > > has problem with old kexec, it only copy header from bzImage include > setup_header as boot_param. > How old are we talking here? This is a clear and blatant bug, and it would affect a whole bunch of things, not just this. In fact, one really has to wonder how it can work at all. One option I guess would be to have a sentinel field which, if it is not zero, causes the kernel to zero all of struct setup_info outside of setup_header... however, I have a nasty suspicion that this kexec botch might be initializing some fields and leaving others unmodified, which basically means "there is no hope for sanity and it is just working by pure accident." Eric, do you have any insight here? > looks we only can use [0x30,0x3c), [0x1e8, 0x1f0), but in boot_params, they > are apm_bios_info, and alt_mem_k... ... which I suspect get set by said kexec botch. > so looks we still have to use setup_header instead. We need to dig into this and either say "this is unsupportable" or put in some kind of hack. -hpa -- H. Peter Anvin, Intel Open Source Technology Center I work for Intel. I don't speak on their behalf.