From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751345AbcGMUAz (ORCPT ); Wed, 13 Jul 2016 16:00:55 -0400 Received: from mout.kundenserver.de ([212.227.17.10]:52857 "EHLO mout.kundenserver.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751009AbcGMUAr (ORCPT ); Wed, 13 Jul 2016 16:00:47 -0400 From: Arnd Bergmann To: Thiago Jung Bauermann Cc: Mark Rutland , linuxppc-dev@lists.ozlabs.org, Dave Young , linux-arm-kernel@lists.infradead.org, bhe@redhat.com, kexec@lists.infradead.org, linux-kernel@vger.kernel.org, AKASHI Takahiro , "Eric W. Biederman" , Vivek Goyal Subject: Re: [RFC 0/3] extend kexec_file_load system call Date: Wed, 13 Jul 2016 21:59:18 +0200 Message-ID: <5108278.va6WuahHro@wuerfel> User-Agent: KMail/5.1.3 (Linux/4.4.0-28-generic; KDE/5.18.0; x86_64; ; ) In-Reply-To: <2222184.ZN0KkkXgPC@hactar> References: <20160712014201.11456-1-takahiro.akashi@linaro.org> <7352796.seiSnHrYPy@wuerfel> <2222184.ZN0KkkXgPC@hactar> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="us-ascii" X-Provags-ID: V03:K0:YmSdnRJQqgAInaypEuIznFprwENnXgRH3BJmdh9bzhY8TAASKkN LSXiJ1CHva1GLpMXLJkppIRMlyXFC1K16lXQ/8vNQ2fMDEGvnXvQjOIGvZAT78FklH4Dyqu 8ERag1F3iRk4VJSLXI0pqCWResctMDTzXTsUV0evilZ2HRm5UcYKe4xJ1QiaJ7nQOJm7jO/ v89NQtAQhaW9ooO0v39eQ== X-UI-Out-Filterresults: notjunk:1;V01:K0:QGoTNxFGjro=:2LRqpHbY/QZYjqSNgOJvSj QAaNQOcroykCJWrHMLyZs1mJ/fcsmj8swg2qI063Hu+3eJcBefBtwPH08qWsKu9rN8jLyyEnG NF5vUtEWx+tECHuUdHfqdxEz0DuWBZJlMfzXl/1xvUHAYiaCNG4Hmy/UEqDuMDYRC3g6omCf4 3a6VMPIbpIwI4IQp25ysPbe0ugnCIdgl7zYg99t7nhAWbIAe2Waj/sOlQ/0w/H+1EMlq+phwu pfFwpXsId/wckqK5OlFIp6ujK2a1GVSkvCIWcCHhzejap750UBaV4oK2ouHmz/JWIgHmBsP/8 Y4i4TkLGzFeMuEJDLlxmymRSx8xAlQP8hNLIfRyI3oUiN3l1rznB0r6+JXwbG1QMTeri/wSaw NtOOZQQgmmm0fc2LOS46WYu1S/N63tMpubvXEcNKajSP01fWqet9GZZySu9d8rBefb+AGOD3v o0dELPiM8lGQiSceGMv17jyNij68hrGAzc0eGfd8N7r7WHEgjNwRE5DbsyvAY3t2p6NDYC9Fn TikhZCmQuUUSOfbZGcFjGjPZD+Gem2HO5k1DGXNqSs6SwsI4Hqbg1ehTHS7gGjZ48DXRIZnDf E+PAUEugfq8XRPCvMkGya8d7/YDAwWLaik5sCY3NCpjf14q3+e1Lbuhdnrb8O51AVnuuZsUaY UNHiODYLsCFgpFXQt9L4g4OWJguVPory5Etq4xHP3PHc8JH/FxWvydMeAyls75+QXt7goKm39 uSyypGppv/7a50Ja Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wednesday, July 13, 2016 3:45:41 PM CEST Thiago Jung Bauermann wrote: > Am Mittwoch, 13 Juli 2016, 15:13:42 schrieb Arnd Bergmann: > > On Wednesday, July 13, 2016 10:41:28 AM CEST Mark Rutland wrote: > > > On Wed, Jul 13, 2016 at 10:01:33AM +0200, Arnd Bergmann wrote: > > > > - kboot/petitboot with all of the user space being part of the trusted > > > > boot> > > > > > chain: it would be good to allow these to modify the dtb as needed > > > > without breaking the trust chain, just like we allow grub or u-boot > > > > to modify the dtb before passing it to the kernel. > > > > > > It depends on *what* we need to modify here. We can modify the bootargs > > > and initrd properties as part of the kexec_file_load syscall, so what > > > else would we want to alter? > > > > I guess petitboot can also just use kexec_load() instead of > > kexec_file_load(), as long as the initramfs containing petitboot is > > trusted by the kernel. > > For secure boot, Petitboot needs to use kexec_file_load, because of the > following two features which the system call enables: > > 1. only allow loading of signed kernels. > 2. "measure" (i.e., record the hashes of) the kernel, initrd, kernel > command line and other boot inputs for the Integrity Measurement > Architecture subsystem. > > Those can't be done with kexec_load. Can't petitboot do both of these in user space? Arnd