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=-3.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 1A2E2C433DF for ; Thu, 21 May 2020 21:34:50 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id C7AFB204EA for ; Thu, 21 May 2020 21:34:49 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org C7AFB204EA Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linutronix.de Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 56B7080009; Thu, 21 May 2020 17:34:49 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 4F45B80007; Thu, 21 May 2020 17:34:49 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 3E34680009; Thu, 21 May 2020 17:34:49 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0205.hostedemail.com [216.40.44.205]) by kanga.kvack.org (Postfix) with ESMTP id 226F480007 for ; Thu, 21 May 2020 17:34:49 -0400 (EDT) Received: from smtpin19.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with ESMTP id DB09C3AB7 for ; Thu, 21 May 2020 21:34:48 +0000 (UTC) X-FDA: 76842031056.19.sheet52_8149028cb2229 X-HE-Tag: sheet52_8149028cb2229 X-Filterd-Recvd-Size: 2732 Received: from Galois.linutronix.de (Galois.linutronix.de [193.142.43.55]) by imf18.hostedemail.com (Postfix) with ESMTP for ; Thu, 21 May 2020 21:34:48 +0000 (UTC) Received: from p5de0bf0b.dip0.t-ipconnect.de ([93.224.191.11] helo=nanos.tec.linutronix.de) by Galois.linutronix.de with esmtpsa (TLS1.2:DHE_RSA_AES_256_CBC_SHA256:256) (Exim 4.80) (envelope-from ) id 1jbspg-0002Dw-US; Thu, 21 May 2020 23:34:29 +0200 Received: by nanos.tec.linutronix.de (Postfix, from userid 1000) id DE9AA100C2D; Thu, 21 May 2020 23:34:27 +0200 (CEST) From: Thomas Gleixner To: Yu-cheng Yu , x86@kernel.org, "H. Peter Anvin" , 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 Cc: Yu-cheng Yu Subject: Re: [RFC PATCH 4/5] selftest/x86: Fix sysret_rip with ENDBR In-Reply-To: <20200521211720.20236-5-yu-cheng.yu@intel.com> References: <20200521211720.20236-1-yu-cheng.yu@intel.com> <20200521211720.20236-5-yu-cheng.yu@intel.com> Date: Thu, 21 May 2020 23:34:27 +0200 Message-ID: <878shlt1jw.fsf@nanos.tec.linutronix.de> MIME-Version: 1.0 Content-Type: text/plain X-Linutronix-Spam-Score: -1.0 X-Linutronix-Spam-Level: - X-Linutronix-Spam-Status: No , -1.0 points, 5.0 required, ALL_TRUSTED=-1,SHORTCIRCUIT=-0.0001 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: Yu-cheng Yu writes: > Insert endbr64 to assembly code of sysret_rip. This changelog explains what the patch does, but not the WHY. It also lacks any information why this is harmless for !CET enabled systems. > Signed-off-by: Yu-cheng Yu > --- Please consult Dave Hansen about the void between your Signed-off-by and the '---' line. Thanks, tglx