From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from terminus.zytor.com ([2001:1868:205::10] helo=mail.zytor.com) by merlin.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1VJWoR-0004Vl-69 for kexec@lists.infradead.org; Tue, 10 Sep 2013 22:53:35 +0000 Message-ID: <522FA2A8.8080703@zytor.com> Date: Tue, 10 Sep 2013 15:52:24 -0700 From: "H. Peter Anvin" MIME-Version: 1.0 Subject: Re: [PATCH 15/16] bootparam: Pass acpi_rsdp pointer in bootparam References: <1378849471-10521-1-git-send-email-vgoyal@redhat.com> <1378849471-10521-16-git-send-email-vgoyal@redhat.com> In-Reply-To: <1378849471-10521-16-git-send-email-vgoyal@redhat.com> List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "kexec" Errors-To: kexec-bounces+dwmw2=twosheds.infradead.org@lists.infradead.org To: Vivek Goyal Cc: matthew.garrett@nebula.com, d.kasatkin@samsung.com, kexec@lists.infradead.org, linux-kernel@vger.kernel.org, linux-security-module@vger.kernel.org, Borislav Petkov , ebiederm@xmission.com, akpm@linux-foundation.org, zohar@linux.vnet.ibm.com On 09/10/2013 02:44 PM, Vivek Goyal wrote: > Currently kexec does not enables EFI and its tables in second kernel. Hence > acpi rsdp root pointer is passed on command line. But secureboot does not trust > acpi_rsdp on command line as kernel can execute some of the code as retrieved > by following acpi_rsdp and root can modify command line. So in secureboot > mode we ignore acpi_rsdp on command line. > > Start passing it in bootparams for the time being. kexec-tools will prepare > the bootparams and put acpi_rsdp pointer there. > > Peter Jones suggested that scan all ACPI memory for acpi_rsdp if EFI is > not enabled. This probably is a better fix and most likely this patch will > change and adopt that approach down the line. > > In fact if we figure out how to make UEFI run time calls in second kernel, > we will not need acpi_rsdp at all. > Borislav Petkov has been working on a fixed mapping of UEFI memory, which should allow UEFI runtime calls across kexec. -hpa _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752239Ab3IJWxr (ORCPT ); Tue, 10 Sep 2013 18:53:47 -0400 Received: from terminus.zytor.com ([198.137.202.10]:45388 "EHLO mail.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751230Ab3IJWxo (ORCPT ); Tue, 10 Sep 2013 18:53:44 -0400 Message-ID: <522FA2A8.8080703@zytor.com> Date: Tue, 10 Sep 2013 15:52:24 -0700 From: "H. Peter Anvin" User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130805 Thunderbird/17.0.8 MIME-Version: 1.0 To: Vivek Goyal CC: linux-kernel@vger.kernel.org, linux-security-module@vger.kernel.org, kexec@lists.infradead.org, akpm@linux-foundation.org, zohar@linux.vnet.ibm.com, d.kasatkin@samsung.com, ebiederm@xmission.com, matthew.garrett@nebula.com, Borislav Petkov Subject: Re: [PATCH 15/16] bootparam: Pass acpi_rsdp pointer in bootparam References: <1378849471-10521-1-git-send-email-vgoyal@redhat.com> <1378849471-10521-16-git-send-email-vgoyal@redhat.com> In-Reply-To: <1378849471-10521-16-git-send-email-vgoyal@redhat.com> 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 On 09/10/2013 02:44 PM, Vivek Goyal wrote: > Currently kexec does not enables EFI and its tables in second kernel. Hence > acpi rsdp root pointer is passed on command line. But secureboot does not trust > acpi_rsdp on command line as kernel can execute some of the code as retrieved > by following acpi_rsdp and root can modify command line. So in secureboot > mode we ignore acpi_rsdp on command line. > > Start passing it in bootparams for the time being. kexec-tools will prepare > the bootparams and put acpi_rsdp pointer there. > > Peter Jones suggested that scan all ACPI memory for acpi_rsdp if EFI is > not enabled. This probably is a better fix and most likely this patch will > change and adopt that approach down the line. > > In fact if we figure out how to make UEFI run time calls in second kernel, > we will not need acpi_rsdp at all. > Borislav Petkov has been working on a fixed mapping of UEFI memory, which should allow UEFI runtime calls across kexec. -hpa