From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755488Ab3JKQrc (ORCPT ); Fri, 11 Oct 2013 12:47:32 -0400 Received: from b.ns.miles-group.at ([95.130.255.144]:1660 "EHLO radon.swed.at" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1755324Ab3JKQra (ORCPT ); Fri, 11 Oct 2013 12:47:30 -0400 Message-ID: <52582B97.2060907@nod.at> Date: Fri, 11 Oct 2013 18:47:19 +0200 From: Richard Weinberger User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130620 Thunderbird/17.0.7 MIME-Version: 1.0 To: Matthew Garrett CC: Richard Weinberger , Vivek Goyal , Daniel Kiper , "Eric W. Biederman" , hbabu@us.ibm.com, "H. Peter Anvin" , Kees Cook , kexec@lists.infradead.org, LKML , david.vrabel@citrix.com, jbeulich@suse.com, keir@xen.org, xen-devel@lists.xen.org Subject: Re: kexec: Clearing registers just before jumping into purgatory References: <20131011092837.GZ3626@debian70-amd64.local.net-space.pl> <877gdkce6s.fsf@tw-ebiederman.twitter.com> <20131011110455.GA3626@debian70-amd64.local.net-space.pl> <20131011125206.GA2772@redhat.com> <20131011153727.GA30181@srcf.ucam.org> <20131011154450.GB2772@redhat.com> <20131011154805.GB30181@srcf.ucam.org> <20131011163933.GA31941@srcf.ucam.org> <20131011164400.GA32133@srcf.ucam.org> In-Reply-To: <20131011164400.GA32133@srcf.ucam.org> X-Enigmail-Version: 1.5.2 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Am 11.10.2013 18:44, schrieb Matthew Garrett: > On Fri, Oct 11, 2013 at 06:42:36PM +0200, Richard Weinberger wrote: >> On Fri, Oct 11, 2013 at 6:39 PM, Matthew Garrett wrote: >>> On Fri, Oct 11, 2013 at 06:33:23PM +0200, Richard Weinberger wrote: >>>> On Fri, Oct 11, 2013 at 5:48 PM, Matthew Garrett wrote: >>>>> On Fri, Oct 11, 2013 at 11:44:50AM -0400, Vivek Goyal wrote: >>>>> >>>>>> Just Curious. How is it useful. IOW, what's your use case of booting a new >>>>>> kernel and then jumping back. >>>>> >>>>> I'm kexecing into a kernel with a modified /dev/mem, modifying the >>>>> original kernel and then jumping back into it. >>>> >>>> How do you update the original kernel? >>> >>> It's still in RAM, so the same way you'd modify any other arbitrary >>> physical address? >> >> So, you have a tool like ksplice which patches the kernel in RAM? > > I have /dev/mem and a list of addresses I want to modify. But you still need a magic tool which create you this list. If you have a tool which takes two kernel images and create such a delta, fine. I'm interested in that tool. :-) Thanks, //richard