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 A93F7C433ED for ; Wed, 28 Apr 2021 14:52:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6FB5C61008 for ; Wed, 28 Apr 2021 14:52:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240268AbhD1OxT (ORCPT ); Wed, 28 Apr 2021 10:53:19 -0400 Received: from mail.kernel.org ([198.145.29.99]:34952 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S240259AbhD1OxS (ORCPT ); Wed, 28 Apr 2021 10:53:18 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 3322161440 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-f47.google.com with SMTP id g14so14898577edy.6 for ; Wed, 28 Apr 2021 07:52:33 -0700 (PDT) X-Gm-Message-State: AOAM532mM5v3J1cXkTmpI+rrUwajL1E4liSa438EGicM1/pMIhhp1+Eu TlX5Ufv109aEr7B40nzq9GZQDAF36GyHxvqlCwaGBA== 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" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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