From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760635Ab0I1Drk (ORCPT ); Mon, 27 Sep 2010 23:47:40 -0400 Received: from terminus.zytor.com ([198.137.202.10]:50295 "EHLO mail.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758059Ab0I1Drj (ORCPT ); Mon, 27 Sep 2010 23:47:39 -0400 Message-ID: <4CA16522.8060107@zytor.com> Date: Mon, 27 Sep 2010 20:46:42 -0700 From: "H. Peter Anvin" User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.2.9) Gecko/20100907 Fedora/3.1.3-1.fc13 Thunderbird/3.1.3 MIME-Version: 1.0 To: Vivek Goyal CC: Yinghai Lu , Ingo Molnar , kexec , caiqian@redhat.com, linux-kernel@vger.kernel.org Subject: Re: kexec load failure introduced by "x86, memblock: Replace e820_/_early string with memblock_" References: <632974489.2046131285586512527.JavaMail.root@zmail06.collab.prod.int.phx2.redhat.com> <4CA11918.7050708@kernel.org> <4CA11FB7.2080101@zytor.com> <4CA126BE.7000609@kernel.org> <4CA1283C.9010105@zytor.com> <4CA12976.5060504@kernel.org> <4CA129EB.5000309@zytor.com> <4CA12BAB.1040308@kernel.org> <20100928005358.GA6456@redhat.com> In-Reply-To: <20100928005358.GA6456@redhat.com> 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 On 09/27/2010 05:53 PM, Vivek Goyal wrote: > > Actually, hardcoding the upper limit to 4G is probably not the best idea. > Kexec loads the the relocatable binary (purgatory) and I remember that > one of the generated relocation type was signed 32 bit and allowed max value > to be 2G only. So IIRC, purgatory code always needed to be loaded below 2G. > > I liked HPA's other idea better of introducing memblock_find_in_range_lowest() > so that we search bottom up and not rely on a specific upper limit. > No, it's just another crappy hack which is broken in the same way. It's better than open-coding, but it's still a hack. The Right Thing[TM] to do is for kexec to communicate the topmost address it wants to this code, so it has both the upper and the lower boundaries available to it instead of just one. -hpa -- H. Peter Anvin, Intel Open Source Technology Center I work for Intel. I don't speak on their behalf.