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=-13.0 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable 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 B5AE4C433E1 for ; Fri, 17 Jul 2020 17:01:24 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9609E208C7 for ; Fri, 17 Jul 2020 17:01:24 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728108AbgGQRAy (ORCPT ); Fri, 17 Jul 2020 13:00:54 -0400 Received: from mga18.intel.com ([134.134.136.126]:1883 "EHLO mga18.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726938AbgGQRAx (ORCPT ); Fri, 17 Jul 2020 13:00:53 -0400 IronPort-SDR: bTi94862T7nBQMCgUaPxkf7WAddi+kzWSTVh3cEvI2APVZGkqIRmqRoHLYShKdllJBdAE2pOJd 1kTHRsvVkkvw== X-IronPort-AV: E=McAfee;i="6000,8403,9685"; a="137102881" X-IronPort-AV: E=Sophos;i="5.75,362,1589266800"; d="scan'208";a="137102881" X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga008.fm.intel.com ([10.253.24.58]) by orsmga106.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 17 Jul 2020 10:00:50 -0700 IronPort-SDR: /V6RtfUS+C686duNWWoKoKTY1Px7zJvGYSGnXaZmHpZxO+uuOWVeof5/iYHkrPO+i1HAgzStE+ upAd5+rglRDw== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.75,362,1589266800"; d="scan'208";a="270862091" Received: from kcaccard-mobl.amr.corp.intel.com (HELO kcaccard-mobl1.jf.intel.com) ([10.212.33.149]) by fmsmga008.fm.intel.com with ESMTP; 17 Jul 2020 10:00:43 -0700 From: Kristen Carlson Accardi To: keescook@chromium.org, tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, x86@kernel.org, "H. Peter Anvin" , Arnd Bergmann Cc: arjan@linux.intel.com, linux-kernel@vger.kernel.org, kernel-hardening@lists.openwall.com, rick.p.edgecombe@intel.com, Kristen Carlson Accardi , Tony Luck , linux-arch@vger.kernel.org Subject: [PATCH v4 05/10] x86: Make sure _etext includes function sections Date: Fri, 17 Jul 2020 10:00:02 -0700 Message-Id: <20200717170008.5949-6-kristen@linux.intel.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20200717170008.5949-1-kristen@linux.intel.com> References: <20200717170008.5949-1-kristen@linux.intel.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org When using -ffunction-sections to place each function in it's own text section so it can be randomized at load time, the linker considers these .text.* sections "orphaned sections", and will place them after the first similar section (.text). In order to accurately represent the end of the text section and the orphaned sections, _etext must be moved so that it is after both .text and .text.* The text size must also be calculated to include .text AND .text.* Signed-off-by: Kristen Carlson Accardi Reviewed-by: Tony Luck Tested-by: Tony Luck Reviewed-by: Kees Cook --- arch/x86/kernel/vmlinux.lds.S | 17 +++++++++++++++-- include/asm-generic/vmlinux.lds.h | 2 +- 2 files changed, 16 insertions(+), 3 deletions(-) diff --git a/arch/x86/kernel/vmlinux.lds.S b/arch/x86/kernel/vmlinux.lds.S index 3bfc8dd8a43d..e8da7eeb4d8d 100644 --- a/arch/x86/kernel/vmlinux.lds.S +++ b/arch/x86/kernel/vmlinux.lds.S @@ -146,9 +146,22 @@ SECTIONS #endif } :text =0xcccc - /* End of text section, which should occupy whole number of pages */ - _etext = .; + /* + * -ffunction-sections creates .text.* sections, which are considered + * "orphan sections" and added after the first similar section (.text). + * Placing this ALIGN statement before _etext causes the address of + * _etext to be below that of all the .text.* orphaned sections + */ . = ALIGN(PAGE_SIZE); + _etext = .; + + /* + * the size of the .text section is used to calculate the address + * range for orc lookups. If we just use SIZEOF(.text), we will + * miss all the .text.* sections. Calculate the size using _etext + * and _stext and save the value for later. + */ + text_size = _etext - _stext; X86_ALIGN_RODATA_BEGIN RO_DATA(PAGE_SIZE) diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h index a5552cf28d5d..34eab6513fdc 100644 --- a/include/asm-generic/vmlinux.lds.h +++ b/include/asm-generic/vmlinux.lds.h @@ -835,7 +835,7 @@ . = ALIGN(4); \ .orc_lookup : AT(ADDR(.orc_lookup) - LOAD_OFFSET) { \ orc_lookup = .; \ - . += (((SIZEOF(.text) + LOOKUP_BLOCK_SIZE - 1) / \ + . += (((text_size + LOOKUP_BLOCK_SIZE - 1) / \ LOOKUP_BLOCK_SIZE) + 1) * 4; \ orc_lookup_end = .; \ } -- 2.20.1