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=-9.1 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, UNWANTED_LANGUAGE_BODY 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 B258CC32751 for ; Wed, 7 Aug 2019 13:28:24 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 7C86321E6B for ; Wed, 7 Aug 2019 13:28:24 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=zytor.com header.i=@zytor.com header.b="YFcefxxu" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388268AbfHGN2X (ORCPT ); Wed, 7 Aug 2019 09:28:23 -0400 Received: from terminus.zytor.com ([198.137.202.136]:56939 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2388172AbfHGN2W (ORCPT ); Wed, 7 Aug 2019 09:28:22 -0400 Received: from terminus.zytor.com (localhost [127.0.0.1]) by terminus.zytor.com (8.15.2/8.15.2) with ESMTPS id x77DSEfm2699315 (version=TLSv1.3 cipher=TLS_AES_256_GCM_SHA384 bits=256 verify=NO); Wed, 7 Aug 2019 06:28:14 -0700 DKIM-Filter: OpenDKIM Filter v2.11.0 terminus.zytor.com x77DSEfm2699315 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=zytor.com; s=2019071901; t=1565184495; bh=V1LLR+ahDFpMwCEKlzp5Zaz0cWKllC31+XDp4QdxRMk=; h=Date:From:Cc:Reply-To:In-Reply-To:References:To:Subject:From; b=YFcefxxuSruRTDrU9BU0TptZbLj+/PefQBff5N5rseyHa1JDQhdcSqUryplYmsCLI S44KKdy1CWSK+nvsOlIL5yh77E063uxDV7mWa84UO4VwgittJLMmAKEEQ8ks/ihStf owl08OC91QBNco7j5UIYTbDfMm+qw/ufLLHH+fKm1uKYSbkBQcHH00UxcGgJmXozeW zb6jkLPjjkxRbDwoXSS5v+JJrn9jPz3PhkB8t+Zom1JOkHd5jPIUwztqb0gb9CZNgG 87bJdqhn8ws62mHfA/OjF9TSE2jo/8XbRBy7PYzQ/TPmi5CoxbYi6O2N8gxcLTy/mz EfZBrVbaZct3Q== Received: (from tipbot@localhost) by terminus.zytor.com (8.15.2/8.15.2/Submit) id x77DSEs72699312; Wed, 7 Aug 2019 06:28:14 -0700 Date: Wed, 7 Aug 2019 06:28:14 -0700 X-Authentication-Warning: terminus.zytor.com: tipbot set sender to tipbot@zytor.com using -f From: tip-bot for John Hubbard Message-ID: Cc: jhubbard@nvidia.com, linux-kernel@vger.kernel.org, hpa@zytor.com, tglx@linutronix.de, mingo@kernel.org Reply-To: jhubbard@nvidia.com, linux-kernel@vger.kernel.org, tglx@linutronix.de, mingo@kernel.org, hpa@zytor.com In-Reply-To: <20190731054627.5627-2-jhubbard@nvidia.com> References: <20190731054627.5627-2-jhubbard@nvidia.com> To: linux-tip-commits@vger.kernel.org Subject: [tip:x86/boot] x86/boot: Save fields explicitly, zero out everything else Git-Commit-ID: a156cadef2fe445ac423670eace517b39a01ccd0 X-Mailer: tip-git-log-daemon Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit-ID: a156cadef2fe445ac423670eace517b39a01ccd0 Gitweb: https://git.kernel.org/tip/a156cadef2fe445ac423670eace517b39a01ccd0 Author: John Hubbard AuthorDate: Tue, 30 Jul 2019 22:46:27 -0700 Committer: Thomas Gleixner CommitDate: Wed, 7 Aug 2019 15:22:53 +0200 x86/boot: Save fields explicitly, zero out everything else Recent gcc compilers (gcc 9.1) generate warnings about an out of bounds memset, if the memset goes accross several fields of a struct. This generated a couple of warnings on x86_64 builds in sanitize_boot_params(). Fix this by explicitly saving the fields in struct boot_params that are intended to be preserved, and zeroing all the rest. Suggested-by: Thomas Gleixner Suggested-by: H. Peter Anvin Signed-off-by: John Hubbard Signed-off-by: Thomas Gleixner Link: https://lkml.kernel.org/r/20190731054627.5627-2-jhubbard@nvidia.com --- arch/x86/include/asm/bootparam_utils.h | 63 ++++++++++++++++++++++++++-------- 1 file changed, 48 insertions(+), 15 deletions(-) diff --git a/arch/x86/include/asm/bootparam_utils.h b/arch/x86/include/asm/bootparam_utils.h index 101eb944f13c..f5e90a849bca 100644 --- a/arch/x86/include/asm/bootparam_utils.h +++ b/arch/x86/include/asm/bootparam_utils.h @@ -18,6 +18,20 @@ * Note: efi_info is commonly left uninitialized, but that field has a * private magic, so it is better to leave it unchanged. */ + +#define sizeof_mbr(type, member) ({ sizeof(((type *)0)->member); }) + +#define BOOT_PARAM_PRESERVE(struct_member) \ + { \ + .start = offsetof(struct boot_params, struct_member), \ + .len = sizeof_mbr(struct boot_params, struct_member), \ + } + +struct boot_params_to_save { + unsigned int start; + unsigned int len; +}; + static void sanitize_boot_params(struct boot_params *boot_params) { /* @@ -35,21 +49,40 @@ static void sanitize_boot_params(struct boot_params *boot_params) * problems again. */ if (boot_params->sentinel) { - /* fields in boot_params are left uninitialized, clear them */ - boot_params->acpi_rsdp_addr = 0; - memset(&boot_params->ext_ramdisk_image, 0, - (char *)&boot_params->efi_info - - (char *)&boot_params->ext_ramdisk_image); - memset(&boot_params->kbd_status, 0, - (char *)&boot_params->hdr - - (char *)&boot_params->kbd_status); - memset(&boot_params->_pad7[0], 0, - (char *)&boot_params->edd_mbr_sig_buffer[0] - - (char *)&boot_params->_pad7[0]); - memset(&boot_params->_pad8[0], 0, - (char *)&boot_params->eddbuf[0] - - (char *)&boot_params->_pad8[0]); - memset(&boot_params->_pad9[0], 0, sizeof(boot_params->_pad9)); + static struct boot_params scratch; + char *bp_base = (char *)boot_params; + char *save_base = (char *)&scratch; + int i; + + const struct boot_params_to_save to_save[] = { + BOOT_PARAM_PRESERVE(screen_info), + BOOT_PARAM_PRESERVE(apm_bios_info), + BOOT_PARAM_PRESERVE(tboot_addr), + BOOT_PARAM_PRESERVE(ist_info), + BOOT_PARAM_PRESERVE(acpi_rsdp_addr), + BOOT_PARAM_PRESERVE(hd0_info), + BOOT_PARAM_PRESERVE(hd1_info), + BOOT_PARAM_PRESERVE(sys_desc_table), + BOOT_PARAM_PRESERVE(olpc_ofw_header), + BOOT_PARAM_PRESERVE(efi_info), + BOOT_PARAM_PRESERVE(alt_mem_k), + BOOT_PARAM_PRESERVE(scratch), + BOOT_PARAM_PRESERVE(e820_entries), + BOOT_PARAM_PRESERVE(eddbuf_entries), + BOOT_PARAM_PRESERVE(edd_mbr_sig_buf_entries), + BOOT_PARAM_PRESERVE(edd_mbr_sig_buffer), + BOOT_PARAM_PRESERVE(e820_table), + BOOT_PARAM_PRESERVE(eddbuf), + }; + + memset(&scratch, 0, sizeof(scratch)); + + for (i = 0; i < ARRAY_SIZE(to_save); i++) { + memcpy(save_base + to_save[i].start, + bp_base + to_save[i].start, to_save[i].len); + } + + memcpy(boot_params, save_base, sizeof(*boot_params)); } }