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=-11.7 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 09168C34047 for ; Wed, 19 Feb 2020 16:55:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id DD8F924671 for ; Wed, 19 Feb 2020 16:55:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726768AbgBSQzY (ORCPT ); Wed, 19 Feb 2020 11:55:24 -0500 Received: from Galois.linutronix.de ([193.142.43.55]:38822 "EHLO Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726551AbgBSQzV (ORCPT ); Wed, 19 Feb 2020 11:55:21 -0500 Received: from [5.158.153.53] (helo=tip-bot2.lab.linutronix.de) by Galois.linutronix.de with esmtpsa (TLS1.2:DHE_RSA_AES_256_CBC_SHA256:256) (Exim 4.80) (envelope-from ) id 1j4Sd2-0000GR-Kk; Wed, 19 Feb 2020 17:55:16 +0100 Received: from [127.0.1.1] (localhost [IPv6:::1]) by tip-bot2.lab.linutronix.de (Postfix) with ESMTP id 488A41C20C7; Wed, 19 Feb 2020 17:55:16 +0100 (CET) Date: Wed, 19 Feb 2020 16:55:16 -0000 From: "tip-bot2 for Arvind Sankar" Reply-to: linux-kernel@vger.kernel.org To: linux-tip-commits@vger.kernel.org Subject: [tip: x86/boot] x86/boot/compressed/64: Remove .bss/.pgtable from bzImage Cc: Arvind Sankar , Borislav Petkov , Kees Cook , x86 , LKML In-Reply-To: <20200109150218.16544-1-nivedita@alum.mit.edu> References: <20200109150218.16544-1-nivedita@alum.mit.edu> MIME-Version: 1.0 Message-ID: <158213131602.13786.16571739495363216175.tip-bot2@tip-bot2> X-Mailer: tip-git-log-daemon Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit X-Linutronix-Spam-Score: -1.0 X-Linutronix-Spam-Level: - X-Linutronix-Spam-Status: No , -1.0 points, 5.0 required, ALL_TRUSTED=-1,SHORTCIRCUIT=-0.0001 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The following commit has been merged into the x86/boot branch of tip: Commit-ID: 3ee372ccce4d4e7c610748d0583979d3ed3a0cf4 Gitweb: https://git.kernel.org/tip/3ee372ccce4d4e7c610748d0583979d3ed3a0cf4 Author: Arvind Sankar AuthorDate: Thu, 09 Jan 2020 10:02:17 -05:00 Committer: Borislav Petkov CommitterDate: Wed, 19 Feb 2020 17:28:57 +01:00 x86/boot/compressed/64: Remove .bss/.pgtable from bzImage Commit 5b11f1cee579 ("x86, boot: straighten out ranges to copy/zero in compressed/head*.S") introduced a separate .pgtable section, splitting it out from the rest of .bss. This section was added without the writeable flag, marking it as read-only. This results in the linker putting the .rela.dyn section (containing bogus dynamic relocations from head_64.o) after the .bss and .pgtable sections. When objcopy is used to convert compressed/vmlinux into a binary for the bzImage: $ objcopy -O binary -R .note -R .comment -S arch/x86/boot/compressed/vmlinux \ arch/x86/boot/vmlinux.bin the .bss and .pgtable sections get materialized as ~176KiB of zero bytes in the binary in order to place .rela.dyn at the correct location. Fix this by marking .pgtable as writeable. This moves the .rela.dyn section up in the ELF image layout so that .bss and .pgtable are the last allocated sections and so don't appear in bzImage. [ bp: Massage commit message. ] Signed-off-by: Arvind Sankar Signed-off-by: Borislav Petkov Acked-by: Kees Cook Link: https://lkml.kernel.org/r/20200109150218.16544-1-nivedita@alum.mit.edu --- arch/x86/boot/compressed/head_64.S | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/x86/boot/compressed/head_64.S b/arch/x86/boot/compressed/head_64.S index 68f31c4..c8ee6ef 100644 --- a/arch/x86/boot/compressed/head_64.S +++ b/arch/x86/boot/compressed/head_64.S @@ -645,7 +645,7 @@ SYM_DATA_END_LABEL(boot_stack, SYM_L_LOCAL, boot_stack_end) /* * Space for page tables (not in .bss so not zeroed) */ - .section ".pgtable","a",@nobits + .section ".pgtable","aw",@nobits .balign 4096 SYM_DATA_LOCAL(pgtable, .fill BOOT_PGT_SIZE, 1, 0)