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=-8.4 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED, 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 A7001C67839 for ; Fri, 14 Dec 2018 01:29:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6F3702075B for ; Fri, 14 Dec 2018 01:29:37 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 6F3702075B Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=cn.fujitsu.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728983AbeLNB30 (ORCPT ); Thu, 13 Dec 2018 20:29:26 -0500 Received: from mail.cn.fujitsu.com ([183.91.158.132]:56048 "EHLO heian.cn.fujitsu.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1728433AbeLNB3X (ORCPT ); Thu, 13 Dec 2018 20:29:23 -0500 X-IronPort-AV: E=Sophos;i="5.56,350,1539619200"; d="scan'208";a="49732740" Received: from unknown (HELO cn.fujitsu.com) ([10.167.33.5]) by heian.cn.fujitsu.com with ESMTP; 14 Dec 2018 09:29:19 +0800 Received: from G08CNEXCHPEKD01.g08.fujitsu.local (unknown [10.167.33.80]) by cn.fujitsu.com (Postfix) with ESMTP id 0F8E64B734CC; Fri, 14 Dec 2018 09:29:17 +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; Fri, 14 Dec 2018 09:29:16 +0800 Date: Fri, 14 Dec 2018 09:28:51 +0800 From: Chao Fan To: Borislav Petkov CC: , , , , , , , , , Subject: Re: [PATCH v13 3/6] x86/boot: Introduce efi_get_rsdp_addr() to find RSDP from EFI table Message-ID: <20181214012848.GB24409@localhost.localdomain> References: <20181212031053.1815-1-fanc.fnst@cn.fujitsu.com> <20181212031053.1815-4-fanc.fnst@cn.fujitsu.com> <20181213202304.GG25287@zn.tnic> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Disposition: inline In-Reply-To: <20181213202304.GG25287@zn.tnic> User-Agent: Mutt/1.10.1 (2018-07-13) X-Originating-IP: [10.167.225.56] X-yoursite-MailScanner-ID: 0F8E64B734CC.AE91B 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 Thu, Dec 13, 2018 at 09:23:04PM +0100, Borislav Petkov wrote: >On Wed, Dec 12, 2018 at 11:10:50AM +0800, Chao Fan wrote: >> Memory information in SRAT is necessary to fix the conflict between >> KASLR and memory-hotremove. So RSDP and SRAT should be parsed. >> >> When booting form KEXEC/EFI/BIOS, the methods to compute RSDP >> are different. When booting from EFI, EFI table points to RSDP. >> So parse the EFI table and find the RSDP. >> >> Signed-off-by: Chao Fan >> --- >> arch/x86/boot/compressed/acpi.c | 79 +++++++++++++++++++++++++++++++++ >> 1 file changed, 79 insertions(+) >> >> diff --git a/arch/x86/boot/compressed/acpi.c b/arch/x86/boot/compressed/acpi.c >> index cad15686f82c..c96008712ec9 100644 >> --- a/arch/x86/boot/compressed/acpi.c >> +++ b/arch/x86/boot/compressed/acpi.c >> @@ -28,3 +28,82 @@ static acpi_physical_address get_acpi_rsdp(void) >> return 0; >> #endif >> } >> + >> +/* Search EFI table for RSDP. */ >> +static acpi_physical_address efi_get_rsdp_addr(void) >> +{ >> +#ifdef CONFIG_EFI >> + acpi_physical_address rsdp_addr = 0; >> + efi_system_table_t *systab; >> + struct efi_info *e; >> + bool efi_64; >> + char *sig; >> + int size; >> + int i; >> + >> + e = &boot_params->efi_info; >> + sig = (char *)&e->efi_loader_signature; >> + >> + if (!strncmp(sig, EFI64_LOADER_SIGNATURE, 4)) >> + efi_64 = true; >> + else if (!strncmp(sig, EFI32_LOADER_SIGNATURE, 4)) >> + efi_64 = false; >> + else { >> + debug_putstr("Wrong EFI loader signature.\n"); >> + return 0; >> + } > >Use curly braces for all three branches above. > OK, I will add in the first and second. >> + >> + /* Get systab from boot params. Based on efi_init(). */ >> +#ifdef CONFIG_X86_64 >> + systab = (efi_system_table_t *)(e->efi_systab | ((__u64)e->efi_systab_hi<<32)); >> +#else >> + if (e->efi_systab_hi || e->efi_memmap_hi) { >> + debug_putstr("Error getting RSDP address: EFI system table located above 4GB.\n"); >> + return 0; >> + } >> + systab = (efi_system_table_t *)e->efi_systab; >> +#endif >> + >> + if (!systab) >> + return 0; >> + >> + /* >> + * Get EFI tables from systab. Based on efi_config_init() and >> + * efi_config_parse_tables(). >> + */ >> + size = efi_64 ? sizeof(efi_config_table_64_t) : >> + sizeof(efi_config_table_32_t); >> + >> + for (i = 0; i < systab->nr_tables; i++) { >> + void *config_tables; >> + unsigned long table; >> + efi_guid_t guid; >> + >> + config_tables = (void *)(systab->tables + size * i); >> + if (efi_64) { >> + efi_config_table_64_t *tmp_table; >> + >> + tmp_table = (efi_config_table_64_t *)config_tables; >> + guid = tmp_table->guid; >> + table = tmp_table->table; >> + >> + if (!IS_ENABLED(CONFIG_X86_64) && table >> 32) { >> + debug_putstr("Error getting RSDP address: EFI system table located above 4GB.\n"); > >Do s/system/config/ here so that this error message is different from >the one above. Yes, will change it. > >> + return 0; >> + } >> + } else { >> + efi_config_table_32_t *tmp_table; >> + >> + tmp_table = (efi_config_table_32_t *)config_tables; >> + guid = tmp_table->guid; >> + table = tmp_table->table; >> + } >> + >> + if (!(efi_guidcmp(guid, ACPI_TABLE_GUID))) >> + rsdp_addr = (acpi_physical_address)table; >> + else if (!(efi_guidcmp(guid, ACPI_20_TABLE_GUID))) >> + return (acpi_physical_address)table; >> + } >> + return rsdp_addr; >> +#endif > > } >#endif > return rsdp_addr; >} > >IOW, you have: > >static acpi_physical_address efi_get_rsdp_addr(void) >{ > acpi_physical_address rsdp_addr = 0; >#ifdef CONFIG_EFI > ... >#endif > return rsdp_addr; >} Make sense. Thanks. Thanks, Chao Fan > >-- >Regards/Gruss, > Boris. > >Good mailing practices for 400: avoid top-posting and trim the reply. > >