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=-2.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,PDS_BAD_THREAD_QP_64, 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 35327C43462 for ; Wed, 28 Apr 2021 14:48:41 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id ADD3A61433 for ; Wed, 28 Apr 2021 14:48:40 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org ADD3A61433 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=ACULAB.COM Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 1F4886B0070; Wed, 28 Apr 2021 10:48:40 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 1CC446B0071; Wed, 28 Apr 2021 10:48:40 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 06D676B0072; Wed, 28 Apr 2021 10:48:40 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0059.hostedemail.com [216.40.44.59]) by kanga.kvack.org (Postfix) with ESMTP id E0D736B0070 for ; Wed, 28 Apr 2021 10:48:39 -0400 (EDT) Received: from smtpin32.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with ESMTP id 9A1B6181AF5C2 for ; Wed, 28 Apr 2021 14:48:39 +0000 (UTC) X-FDA: 78082057158.32.4C0DE22 Received: from eu-smtp-delivery-151.mimecast.com (eu-smtp-delivery-151.mimecast.com [185.58.86.151]) by imf19.hostedemail.com (Postfix) with ESMTP id 07F4590009F1 for ; Wed, 28 Apr 2021 14:48:08 +0000 (UTC) Received: from AcuMS.aculab.com (156.67.243.121 [156.67.243.121]) (Using TLS) by relay.mimecast.com with ESMTP id uk-mta-213-Q40LSYhmNgio6b75f9Ipug-1; Wed, 28 Apr 2021 15:48:34 +0100 X-MC-Unique: Q40LSYhmNgio6b75f9Ipug-1 Received: from AcuMS.Aculab.com (fd9f:af1c:a25b:0:994c:f5c2:35d6:9b65) by AcuMS.aculab.com (fd9f:af1c:a25b:0:994c:f5c2:35d6:9b65) with Microsoft SMTP Server (TLS) id 15.0.1497.2; Wed, 28 Apr 2021 15:48:32 +0100 Received: from AcuMS.Aculab.com ([fe80::994c:f5c2:35d6:9b65]) by AcuMS.aculab.com ([fe80::994c:f5c2:35d6:9b65%12]) with mapi id 15.00.1497.015; Wed, 28 Apr 2021 15:48:32 +0100 From: David Laight To: '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" Subject: RE: [PATCH v26 0/9] Control-flow Enforcement: Indirect Branch Tracking Thread-Topic: [PATCH v26 0/9] Control-flow Enforcement: Indirect Branch Tracking Thread-Index: AQHXO6ae1Nsozyj+DkCGokhshY0p/arKAkvw Date: Wed, 28 Apr 2021 14:48:32 +0000 Message-ID: <0e03c50ea05440209d620971b9db4f29@AcuMS.aculab.com> References: <20210427204720.25007-1-yu-cheng.yu@intel.com> In-Reply-To: <20210427204720.25007-1-yu-cheng.yu@intel.com> Accept-Language: en-GB, en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-ms-exchange-transport-fromentityheader: Hosted x-originating-ip: [10.202.205.107] MIME-Version: 1.0 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=C51A453 smtp.mailfrom=david.laight@aculab.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: aculab.com Content-Language: en-US Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable X-Rspamd-Server: rspam05 X-Rspamd-Queue-Id: 07F4590009F1 X-Stat-Signature: 7ronm43fpaj1hmagbuq9iwn4j69cmzzr Received-SPF: none (aculab.com>: No applicable sender policy available) receiver=imf19; identity=mailfrom; envelope-from=""; helo=eu-smtp-delivery-151.mimecast.com; client-ip=185.58.86.151 X-HE-DKIM-Result: none/none X-HE-Tag: 1619621288-482674 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: From: Yu-cheng Yu > Sent: 27 April 2021 21:47 >=20 > Control-flow Enforcement (CET) is a new Intel processor feature that bloc= ks > 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? =09David - Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1= PT, UK Registration No: 1397386 (Wales)