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=-6.2 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS 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 CC59FC433B4 for ; Wed, 28 Apr 2021 14:52:36 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 37A8561151 for ; Wed, 28 Apr 2021 14:52:36 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 37A8561151 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 9E0716B0070; Wed, 28 Apr 2021 10:52:35 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 968C06B0071; Wed, 28 Apr 2021 10:52:35 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 7E2986B0072; Wed, 28 Apr 2021 10:52:35 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0062.hostedemail.com [216.40.44.62]) by kanga.kvack.org (Postfix) with ESMTP id 5DE896B0070 for ; Wed, 28 Apr 2021 10:52:35 -0400 (EDT) Received: from smtpin18.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with ESMTP id 187F5824999B for ; Wed, 28 Apr 2021 14:52:35 +0000 (UTC) X-FDA: 78082067070.18.04AC814 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by imf23.hostedemail.com (Postfix) with ESMTP id 3227EA0003A2 for ; Wed, 28 Apr 2021 14:52:30 +0000 (UTC) Received: by mail.kernel.org (Postfix) with ESMTPSA id 4025961441 for ; Wed, 28 Apr 2021 14:52:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1619621553; bh=v9MXjcMFDkwGRxGtKjG0QxDDhk6y4//cm0KjKwV14/0=; h=References:In-Reply-To:From:Date:Subject:To:Cc:From; b=KRG/4bXmqOpbEk2St/DRgo26OHKoEpvaJMcORuhBhJnAKSJO0hf22cyOzkqsqg7XJ NMBdrJ7AZp2Ifo59fj4Vk9u7RorERhLrwUapTwJLqqzV3IGaWJL5G06xIuGiogYHET b532Nv7EFUmxnIklw4vgXoHXRvRp5YuXx5u/MrA917KjaLWZ05kn65qG+o8QD3hwhg x0luXKQvpp1LpHfDmnvy1qm4DrsITXKKm6eRWgnsFuWGt4lA/Uv4+4Igr+o7FGb+Tg fN6BEMDxbs2tA9WFGcVPAO/4Qop+TNJjVaW3vlEdo0PmXfueeKeiWGCaWw9b1sbzHz kmbBpzDOXP1LQ== Received: by mail-ed1-f44.google.com with SMTP id c22so10935409edn.7 for ; Wed, 28 Apr 2021 07:52:33 -0700 (PDT) X-Gm-Message-State: AOAM531409MjVX4TO8lqMq8w0koGroggBJwJLJv7IOYMYOM3Wpw6poTM CfF/dYRXu3rg4I2rwsmGfn3BNKHO8BSEa1pGNjOJog== X-Google-Smtp-Source: ABdhPJz+QIzKaPnT4DT6hm809Ge+488Ygp48T6Uu+3gaGnaUVYy9et+z5f3TMrjkz6M7tyk1lUqB4cQlJnvVlzDNxh4= X-Received: by 2002:a05:6402:cbb:: with SMTP id cn27mr12113500edb.222.1619621551563; Wed, 28 Apr 2021 07:52:31 -0700 (PDT) MIME-Version: 1.0 References: <20210427204720.25007-1-yu-cheng.yu@intel.com> <0e03c50ea05440209d620971b9db4f29@AcuMS.aculab.com> In-Reply-To: <0e03c50ea05440209d620971b9db4f29@AcuMS.aculab.com> From: Andy Lutomirski Date: Wed, 28 Apr 2021 07:52:19 -0700 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [PATCH v26 0/9] Control-flow Enforcement: Indirect Branch Tracking To: David Laight Cc: Yu-cheng Yu , "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 Content-Type: text/plain; charset="UTF-8" X-Rspamd-Server: rspam03 X-Rspamd-Queue-Id: 3227EA0003A2 X-Stat-Signature: hjqtsywojcpx4ocr48md7tujykrex3j6 Received-SPF: none (kernel.org>: No applicable sender policy available) receiver=imf23; identity=mailfrom; envelope-from=""; helo=mail.kernel.org; client-ip=198.145.29.99 X-HE-DKIM-Result: pass/pass X-HE-Tag: 1619621550-663558 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 Wed, Apr 28, 2021 at 7:48 AM David Laight wrote: > > From: Yu-cheng Yu > > Sent: 27 April 2021 21:47 > > > > 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]. > ... > > Does this feature require that 'binary blobs' for out of tree drivers > be compiled by a version of gcc that adds the ENDBRA instructions? > > If enabled for userspace, what happens if an old .so is dynamically > loaded? > Or do all userspace programs and libraries have to have been compiled > with the ENDBRA instructions? If you believe that the userspace tooling for the legacy IBT table actually works, then it should just work. Yu-cheng, etc: how well tested is it? --Andy