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=-15.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_SANE_1 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 18C55C433DB for ; Tue, 16 Mar 2021 19:27:28 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id A10DC64EB3 for ; Tue, 16 Mar 2021 19:27:27 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org A10DC64EB3 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 24D986B0036; Tue, 16 Mar 2021 15:27:27 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 1FF606B006C; Tue, 16 Mar 2021 15:27:27 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 0C7A56B006E; Tue, 16 Mar 2021 15:27:27 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0099.hostedemail.com [216.40.44.99]) by kanga.kvack.org (Postfix) with ESMTP id E10EE6B0036 for ; Tue, 16 Mar 2021 15:27:26 -0400 (EDT) Received: from smtpin18.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with ESMTP id 9729C181AF5CA for ; Tue, 16 Mar 2021 19:27:26 +0000 (UTC) X-FDA: 77926721292.18.ACAA6C6 Received: from mga01.intel.com (mga01.intel.com [192.55.52.88]) by imf26.hostedemail.com (Postfix) with ESMTP id 81233407F8DF for ; Tue, 16 Mar 2021 19:27:25 +0000 (UTC) IronPort-SDR: WCqwgL2Br6dGJV40AK8d4h7Q72sDMTgn6FPyI1b1tmvnKA6qlrk6YE4X45QQaF+ZRUYTqIyt1j Q26IryybSROg== X-IronPort-AV: E=McAfee;i="6000,8403,9925"; a="209267522" X-IronPort-AV: E=Sophos;i="5.81,254,1610438400"; d="scan'208";a="209267522" Received: from orsmga003.jf.intel.com ([10.7.209.27]) by fmsmga101.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 16 Mar 2021 12:27:21 -0700 IronPort-SDR: uFgLa216tNsrzWIgcRCdtwQiM9p8zrA76JWNP1+VGm7SvOsa4P1fAsWowUhRqqtgPdRlhqiz7V CgKQgK3Q/nHA== X-IronPort-AV: E=Sophos;i="5.81,254,1610438400"; d="scan'208";a="372079895" Received: from yyu32-mobl1.amr.corp.intel.com (HELO [10.212.191.248]) ([10.212.191.248]) by orsmga003-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 16 Mar 2021 12:27:18 -0700 Subject: Re: [PATCH v23 9/9] x86/vdso: Add ENDBR to __vdso_sgx_enter_enclave To: Jarkko Sakkinen Cc: 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 References: <20210316151320.6123-1-yu-cheng.yu@intel.com> <20210316151320.6123-10-yu-cheng.yu@intel.com> From: "Yu, Yu-cheng" Message-ID: Date: Tue, 16 Mar 2021 12:27:19 -0700 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:78.0) Gecko/20100101 Thunderbird/78.8.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit X-Rspamd-Server: rspam04 X-Rspamd-Queue-Id: 81233407F8DF X-Stat-Signature: 8iz9ah9qkkwptjf557tcpx3pffxakwzw Received-SPF: none (intel.com>: No applicable sender policy available) receiver=imf26; identity=mailfrom; envelope-from=""; helo=mga01.intel.com; client-ip=192.55.52.88 X-HE-DKIM-Result: none/none X-HE-Tag: 1615922845-117321 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: On 3/16/2021 12:22 PM, Jarkko Sakkinen wrote: > On Tue, Mar 16, 2021 at 08:13:19AM -0700, Yu-cheng Yu wrote: >> 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 ENDBR to __vdso_sgx_enter_enclave() branch targets. >> >> Signed-off-by: Yu-cheng Yu >> Cc: Andy Lutomirski >> Cc: Borislav Petkov >> Cc: Dave Hansen >> Cc: Jarkko Sakkinen >> Cc: Peter Zijlstra >> --- >> arch/x86/entry/vdso/vsgx.S | 4 ++++ >> 1 file changed, 4 insertions(+) >> >> diff --git a/arch/x86/entry/vdso/vsgx.S b/arch/x86/entry/vdso/vsgx.S >> index 86a0e94f68df..1baa9b49053e 100644 >> --- a/arch/x86/entry/vdso/vsgx.S >> +++ b/arch/x86/entry/vdso/vsgx.S >> @@ -6,6 +6,7 @@ >> #include >> >> #include "extable.h" >> +#include "../calling.h" >> >> /* Relative to %rbp. */ >> #define SGX_ENCLAVE_OFFSET_OF_RUN 16 >> @@ -27,6 +28,7 @@ >> SYM_FUNC_START(__vdso_sgx_enter_enclave) >> /* Prolog */ >> .cfi_startproc >> + ENDBR >> push %rbp >> .cfi_adjust_cfa_offset 8 >> .cfi_rel_offset %rbp, 0 >> @@ -62,6 +64,7 @@ SYM_FUNC_START(__vdso_sgx_enter_enclave) >> .Lasync_exit_pointer: >> .Lenclu_eenter_eresume: >> enclu >> + ENDBR >> >> /* EEXIT jumps here unless the enclave is doing something fancy. */ >> mov SGX_ENCLAVE_OFFSET_OF_RUN(%rbp), %rbx >> @@ -91,6 +94,7 @@ SYM_FUNC_START(__vdso_sgx_enter_enclave) >> jmp .Lout >> >> .Lhandle_exception: >> + ENDBR >> mov SGX_ENCLAVE_OFFSET_OF_RUN(%rbp), %rbx >> >> /* Set the exception info. */ >> -- >> 2.21.0 >> >> > > Looks good to me. > > Reviewed-by: Jarkko Sakkinen Thanks for reviewing. In response to Dave's and Boris' comments, I will replace ENDBR macro with _CET_ENDBR that comes from the compiler. Can I still keep the Reviewed-by? > > /Jarkko >