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 0F1A0C433E0 for ; Tue, 16 Mar 2021 15:18:24 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D98F7650DC for ; Tue, 16 Mar 2021 15:18:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236360AbhCPPSN (ORCPT ); Tue, 16 Mar 2021 11:18:13 -0400 Received: from mga05.intel.com ([192.55.52.43]:18965 "EHLO mga05.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235850AbhCPPRe (ORCPT ); Tue, 16 Mar 2021 11:17:34 -0400 IronPort-SDR: M0ny2MnNf7VmJiGEqXm3GLFZ27ifWX5FgtamEZKiBKLR/qXS8QYSkcI3419DMmasYftkTZeT98 eGmcEjyjOVfQ== X-IronPort-AV: E=McAfee;i="6000,8403,9924"; a="274320172" X-IronPort-AV: E=Sophos;i="5.81,251,1610438400"; d="scan'208";a="274320172" Received: from orsmga001.jf.intel.com ([10.7.209.18]) by fmsmga105.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 16 Mar 2021 08:13:31 -0700 IronPort-SDR: XMUGFtokid+XPAH9VQHcrNL+ZV5UltfjoavGNjyXATpoL0I04trswapBg305eszfrbRqEB0FEF hjkTLoWaawWw== X-IronPort-AV: E=Sophos;i="5.81,251,1610438400"; d="scan'208";a="449749007" Received: from yyu32-desk.sc.intel.com ([143.183.136.146]) by orsmga001-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 16 Mar 2021 08:13:30 -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 Subject: [PATCH v23 7/9] x86/vdso/32: Add ENDBR to __kernel_vsyscall entry point Date: Tue, 16 Mar 2021 08:13:17 -0700 Message-Id: <20210316151320.6123-8-yu-cheng.yu@intel.com> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20210316151320.6123-1-yu-cheng.yu@intel.com> References: <20210316151320.6123-1-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..adbe948c1a81 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 "../../calling.h" .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