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=-5.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE, SPF_PASS,USER_AGENT_SANE_1 autolearn=no 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 A88D4C433C1 for ; Fri, 19 Mar 2021 21:43:18 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 4A95B60232 for ; Fri, 19 Mar 2021 21:43:18 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 4A95B60232 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 D17696B0080; Fri, 19 Mar 2021 17:43:17 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id CC68B6B0081; Fri, 19 Mar 2021 17:43:17 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id B6AB36B0082; Fri, 19 Mar 2021 17:43:17 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0156.hostedemail.com [216.40.44.156]) by kanga.kvack.org (Postfix) with ESMTP id 999C76B0080 for ; Fri, 19 Mar 2021 17:43:17 -0400 (EDT) Received: from smtpin25.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with ESMTP id 6371C9421 for ; Fri, 19 Mar 2021 21:43:17 +0000 (UTC) X-FDA: 77937950034.25.261D3E0 Received: from mga11.intel.com (mga11.intel.com [192.55.52.93]) by imf04.hostedemail.com (Postfix) with ESMTP id 4129E3D0 for ; Fri, 19 Mar 2021 21:43:10 +0000 (UTC) IronPort-SDR: 0SRmHSAReusx+3mJIJpZ3L9+bIkjekfcaOdw/spn+cf5xR5adhdEZysXHuMVooxk9tcgS4xwW+ hAwIGdOK8Gmg== X-IronPort-AV: E=McAfee;i="6000,8403,9928"; a="186632504" X-IronPort-AV: E=Sophos;i="5.81,262,1610438400"; d="scan'208";a="186632504" Received: from fmsmga006.fm.intel.com ([10.253.24.20]) by fmsmga102.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 19 Mar 2021 14:43:06 -0700 IronPort-SDR: iT/r8ByvMuU8XTKNeF3yq/D/QfUHXYpCYZjIvu/4fy4S0PaDOlSkasOytpgZFg7aZUrat2BnHp M2DQvWQ8JZmw== X-IronPort-AV: E=Sophos;i="5.81,262,1610438400"; d="scan'208";a="603266289" Received: from yyu32-mobl1.amr.corp.intel.com (HELO [10.212.100.40]) ([10.212.100.40]) by fmsmga006-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 19 Mar 2021 14:43:05 -0700 Subject: Re: [PATCH v23 00/28] Control-flow Enforcement: Shadow Stack To: Peter Zijlstra , Borislav Petkov 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 , 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 , Randy Dunlap , "Ravi V. Shankar" , Vedvyas Shanbhogue , Dave Martin , Weijiang Yang , Pengfei Xu , Haitao Huang References: <20210316151054.5405-1-yu-cheng.yu@intel.com> <20210316211552.GU4746@worktop.programming.kicks-ass.net> From: "Yu, Yu-cheng" Message-ID: Date: Fri, 19 Mar 2021 14:43:04 -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: <20210316211552.GU4746@worktop.programming.kicks-ass.net> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit X-Stat-Signature: xwjoj7t74kupdq3gm6eptd49ikypm3j3 X-Rspamd-Server: rspam05 X-Rspamd-Queue-Id: 4129E3D0 Received-SPF: none (intel.com>: No applicable sender policy available) receiver=imf04; identity=mailfrom; envelope-from=""; helo=mga11.intel.com; client-ip=192.55.52.93 X-HE-DKIM-Result: none/none X-HE-Tag: 1616190190-528632 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 2:15 PM, Peter Zijlstra wrote: > On Tue, Mar 16, 2021 at 08:10:26AM -0700, Yu-cheng Yu wrote: >> Control-flow Enforcement (CET) is a new Intel processor feature that blocks >> return/jump-oriented programming attacks. Details are in "Intel 64 and >> IA-32 Architectures Software Developer's Manual" [1]. >> >> CET can protect applications and the kernel. This series enables only >> application-level protection, and has three parts: >> >> - Shadow stack [2], >> - Indirect branch tracking [3], and >> - Selftests [4]. > > CET is marketing; afaict SS and IBT are 100% independent and there's no > reason what so ever to have them share any code, let alone a Kconfig > knob. > > In fact, I think all of this would improve is you remove the CET name > from all of this entirely. Put this series under CONFIG_X86_SHSTK (or > _SS) and use CONFIG_X86_IBT for the other one. > > Similarly with the .c file. > > All this CET business is just pure confusion. > What about this, we bring back CONFIG_X86_SHSTK and CONFIG_X86_IBT. For the CET name itself, can we change it to CFE (Control Flow Enforcement), or just CF? In signal handling, ELF header parsing and arch_prctl(), shadow stack and IBT pretty much share the same code. It is better not to split them into two sets of files. Thanks, Yu-cheng