From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,USER_AGENT_MUTT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id B02D0C282C2 for ; Mon, 11 Feb 2019 01:33:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 84D942146F for ; Mon, 11 Feb 2019 01:33:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726366AbfBKBdg (ORCPT ); Sun, 10 Feb 2019 20:33:36 -0500 Received: from mail.cn.fujitsu.com ([183.91.158.132]:26517 "EHLO heian.cn.fujitsu.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726032AbfBKBdf (ORCPT ); Sun, 10 Feb 2019 20:33:35 -0500 X-IronPort-AV: E=Sophos;i="5.58,357,1544457600"; d="scan'208";a="54006975" Received: from unknown (HELO cn.fujitsu.com) ([10.167.33.5]) by heian.cn.fujitsu.com with ESMTP; 11 Feb 2019 09:33:34 +0800 Received: from G08CNEXCHPEKD01.g08.fujitsu.local (unknown [10.167.33.80]) by cn.fujitsu.com (Postfix) with ESMTP id 9F5FC4BAD925; Mon, 11 Feb 2019 09:33:31 +0800 (CST) Received: from localhost.localdomain (10.167.225.56) by G08CNEXCHPEKD01.g08.fujitsu.local (10.167.33.89) with Microsoft SMTP Server (TLS) id 14.3.408.0; Mon, 11 Feb 2019 09:33:34 +0800 Date: Mon, 11 Feb 2019 09:33:23 +0800 From: Chao Fan To: Borislav Petkov CC: Guenter Roeck , , , , , , , , , , , , , , Ard Biesheuvel , Matt Fleming Subject: Re: [tip:x86/boot] x86/boot: Early parse RSDP and save it in boot_params Message-ID: <20190211013323.GB1544@localhost.localdomain> References: <20190123110850.12433-6-fanc.fnst@cn.fujitsu.com> <20190208190248.GA10854@roeck-us.net> <20190208191024.GL674@zn.tnic> <20190208204451.GA14024@roeck-us.net> <20190208215322.GO674@zn.tnic> <20190211002220.GD14948@zn.tnic> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Disposition: inline In-Reply-To: <20190211002220.GD14948@zn.tnic> User-Agent: Mutt/1.10.1 (2018-07-13) X-Originating-IP: [10.167.225.56] X-yoursite-MailScanner-ID: 9F5FC4BAD925.AEE04 X-yoursite-MailScanner: Found to be clean X-yoursite-MailScanner-From: fanc.fnst@cn.fujitsu.com Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Feb 11, 2019 at 01:22:20AM +0100, Borislav Petkov wrote: >On Fri, Feb 08, 2019 at 10:53:22PM +0100, Borislav Petkov wrote: >> On Fri, Feb 08, 2019 at 12:44:51PM -0800, Guenter Roeck wrote: >> > Yes, the kernel boots if I comment out that function and have it return 0. >> >> Thanks, this localizes the issue significantly. > >Some observations: > > } else { > efi_config_table_32_t *tmp_table; > > tmp_table = config_tables; > guid = tmp_table->guid; <--- * > table = tmp_table->table; > } > >It blows up at that tmp_table->guid deref above. Singlestepping through >it with gdb shows: > ># arch/x86/boot/compressed/acpi.c:114: guid = tmp_table->guid; > movq (%rdi), %rax # MEM[(struct efi_config_table_32_t *)config_tables_37].guid, guid > movq 8(%rdi), %rsi # MEM[(struct efi_config_table_32_t *)config_tables_37].guid, guid ># arch/x86/boot/compressed/acpi.c:115: table = tmp_table->table; > movl 16(%rdi), %r10d # MEM[(struct efi_config_table_32_t *)config_tables_37].table, table > jmp .L30 # > >and %rdi has: > > rdi 0x630646870 > >which is an address above 4G but we're using a 32-bit EFI BIOS. > >Which begs the question whether EFI system tables can even be mapped at >something above 4G with a 32-bit EFI and whether that could work ok. >Hmm. Thanks for your help. As you said, I am not wure whether 32-bit EFI can map table address above 4G. If the map method has problem, I think adding a check here can work. Thanks, Chao Fan > >Lemme add Ard and mfleming for insight here. > >Thx. > >-- >Regards/Gruss, > Boris. > >Good mailing practices for 400: avoid top-posting and trim the reply. > >