From patchwork Fri May 21 22:15:29 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Yu-cheng Yu X-Patchwork-Id: 12273947 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=-16.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT 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 0EA15C4707E for ; Fri, 21 May 2021 22:16:47 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id B4E51613E3 for ; Fri, 21 May 2021 22:16:46 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org B4E51613E3 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=intel.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 761DB8E006F; Fri, 21 May 2021 18:16:35 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 649408E0074; Fri, 21 May 2021 18:16:35 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 363CD8E0072; Fri, 21 May 2021 18:16:35 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0185.hostedemail.com [216.40.44.185]) by kanga.kvack.org (Postfix) with ESMTP id D226D8E0072 for ; Fri, 21 May 2021 18:16:34 -0400 (EDT) Received: from smtpin02.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with ESMTP id 70B55824999B for ; Fri, 21 May 2021 22:16:34 +0000 (UTC) X-FDA: 78166648308.02.C0ADE0C Received: from mga11.intel.com (mga11.intel.com [192.55.52.93]) by imf23.hostedemail.com (Postfix) with ESMTP id 89883A0001C1 for ; Fri, 21 May 2021 22:16:30 +0000 (UTC) IronPort-SDR: snsMhGdDX0XELX9QDpKSGuUTEPhaVhm2/lXnAFGQVkZmmT5iXq27th4mKWWwloaIsUmBQf4EGu PNeKUED0t+iQ== X-IronPort-AV: E=McAfee;i="6200,9189,9991"; a="198500987" X-IronPort-AV: E=Sophos;i="5.82,319,1613462400"; d="scan'208";a="198500987" Received: from fmsmga008.fm.intel.com ([10.253.24.58]) by fmsmga102.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 21 May 2021 15:16:30 -0700 IronPort-SDR: x6ExHnwI+3hUto9HSvZGb6Gq/IO8/NiRup+pQksgpGux8t8CuBK432UCz09lC0A94rPySD80S8 i6Dc1Nlso6gw== X-IronPort-AV: E=Sophos;i="5.82,319,1613462400"; d="scan'208";a="441269459" Received: from yyu32-desk.sc.intel.com ([143.183.136.146]) by fmsmga008-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 21 May 2021 15:16:30 -0700 From: Yu-cheng Yu To: x86@kernel.org, "H. Peter Anvin" , Thomas Gleixner , Ingo Molnar , linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org, linux-mm@kvack.org, linux-arch@vger.kernel.org, linux-api@vger.kernel.org, Arnd Bergmann , Andy Lutomirski , Balbir Singh , Borislav Petkov , Cyrill Gorcunov , Dave Hansen , Eugene Syromiatnikov , Florian Weimer , "H.J. Lu" , Jann Horn , Jonathan Corbet , Kees Cook , Mike Kravetz , Nadav Amit , Oleg Nesterov , Pavel Machek , Peter Zijlstra , Randy Dunlap , "Ravi V. Shankar" , Vedvyas Shanbhogue , Dave Martin , Weijiang Yang , Pengfei Xu , Haitao Huang Cc: Yu-cheng Yu , Jarkko Sakkinen Subject: [PATCH v27 08/10] x86/vdso: Introduce ENDBR macro Date: Fri, 21 May 2021 15:15:29 -0700 Message-Id: <20210521221531.30168-9-yu-cheng.yu@intel.com> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20210521221531.30168-1-yu-cheng.yu@intel.com> References: <20210521221531.30168-1-yu-cheng.yu@intel.com> MIME-Version: 1.0 Authentication-Results: imf23.hostedemail.com; dkim=none; dmarc=fail reason="No valid SPF, No valid DKIM" header.from=intel.com (policy=none); spf=none (imf23.hostedemail.com: domain of yu-cheng.yu@intel.com has no SPF policy when checking 192.55.52.93) smtp.mailfrom=yu-cheng.yu@intel.com X-Rspamd-Server: rspam05 X-Rspamd-Queue-Id: 89883A0001C1 X-Stat-Signature: 8zcyb7xcpyg1cfbonqx9bebz6ffaew5m X-HE-Tag: 1621635390-611982 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: ENDBR is a special new instruction for the Indirect Branch Tracking (IBT) component of CET. IBT prevents attacks by ensuring that (most) indirect branches and function calls may only land at ENDBR instructions. Branches that don't follow the rules will result in control flow (#CF) exceptions. ENDBR is a noop when IBT is unsupported or disabled. Most ENDBR instructions are inserted automatically by the compiler, but branch targets written in assembly must have ENDBR added manually. Introduce ENDBR64/ENDBR32 macros. Signed-off-by: Yu-cheng Yu Reviewed-by: Kees Cook Cc: Andy Lutomirski Cc: Borislav Petkov Cc: Dave Hansen Cc: Jarkko Sakkinen Cc: Peter Zijlstra --- arch/x86/include/asm/vdso.h | 20 +++++++++++++++++++- 1 file changed, 19 insertions(+), 1 deletion(-) diff --git a/arch/x86/include/asm/vdso.h b/arch/x86/include/asm/vdso.h index 98aa103eb4ab..97358246e4c7 100644 --- a/arch/x86/include/asm/vdso.h +++ b/arch/x86/include/asm/vdso.h @@ -52,6 +52,24 @@ extern int map_vdso_once(const struct vdso_image *image, unsigned long addr); extern bool fixup_vdso_exception(struct pt_regs *regs, int trapnr, unsigned long error_code, unsigned long fault_addr); -#endif /* __ASSEMBLER__ */ +#else /* __ASSEMBLER__ */ + +/* + * ENDBR is an instruction for the Indirect Branch Tracking (IBT) component + * of CET. IBT prevents attacks by ensuring that (most) indirect branches + * function calls may only land at ENDBR instructions. Branches that don't + * follow the rules will result in control flow (#CF) exceptions. + * ENDBR is a noop when IBT is unsupported or disabled. Most ENDBR + * instructions are inserted automatically by the compiler, but branch + * targets written in assembly must have ENDBR added manually. + */ +#ifdef CONFIG_X86_IBT +#define ENDBR64 endbr64 +#define ENDBR32 endbr32 +#else +#define ENDBR64 +#define ENDBR32 +#endif +#endif /* __ASSEMBLER__ */ #endif /* _ASM_X86_VDSO_H */