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=-16.8 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=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 87206C433B4 for ; Thu, 1 Apr 2021 22:14:45 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 47E7C6105A for ; Thu, 1 Apr 2021 22:14:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235928AbhDAWOm (ORCPT ); Thu, 1 Apr 2021 18:14:42 -0400 Received: from mga07.intel.com ([134.134.136.100]:20469 "EHLO mga07.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234548AbhDAWO3 (ORCPT ); Thu, 1 Apr 2021 18:14:29 -0400 IronPort-SDR: IUtbehfkovujpejnmPJ2uHLLyyQTeazSc4GX6EtDVupDPXBJ+J5IMJq9/Ixs6/Sw4h6Cqe511G UCOVl94dFRMw== X-IronPort-AV: E=McAfee;i="6000,8403,9941"; a="256322609" X-IronPort-AV: E=Sophos;i="5.81,296,1610438400"; d="scan'208";a="256322609" Received: from orsmga002.jf.intel.com ([10.7.209.21]) by orsmga105.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 01 Apr 2021 15:14:29 -0700 IronPort-SDR: EfFYxmM0btWvPE7M4m9lxafXNEuJwU60qUB73YgMo04Iq28pYo+nQ4DfKzZEaFz/pdcJYC2O8U ltnfRXVZd3yQ== X-IronPort-AV: E=Sophos;i="5.81,296,1610438400"; d="scan'208";a="394700365" Received: from yyu32-desk.sc.intel.com ([143.183.136.146]) by orsmga002-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 01 Apr 2021 15:14:26 -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 Subject: [PATCH v24 8/9] x86/vdso/32: Add ENDBR to __kernel_vsyscall entry point Date: Thu, 1 Apr 2021 15:14:02 -0700 Message-Id: <20210401221403.32253-9-yu-cheng.yu@intel.com> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20210401221403.32253-1-yu-cheng.yu@intel.com> References: <20210401221403.32253-1-yu-cheng.yu@intel.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: "H.J. Lu" 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. Add that to __kernel_vsyscall entry point. Signed-off-by: H.J. Lu Signed-off-by: Yu-cheng Yu Cc: Andy Lutomirski Cc: Kees Cook --- arch/x86/entry/vdso/vdso32/system_call.S | 2 ++ 1 file changed, 2 insertions(+) diff --git a/arch/x86/entry/vdso/vdso32/system_call.S b/arch/x86/entry/vdso/vdso32/system_call.S index de1fff7188aa..c962e7e4f7e3 100644 --- a/arch/x86/entry/vdso/vdso32/system_call.S +++ b/arch/x86/entry/vdso/vdso32/system_call.S @@ -7,6 +7,7 @@ #include #include #include +#include .text .globl __kernel_vsyscall @@ -14,6 +15,7 @@ ALIGN __kernel_vsyscall: CFI_STARTPROC + ENDBR /* * Reshuffle regs so that all of any of the entry instructions * will preserve enough state. -- 2.21.0