Received: by 2002:a25:8b12:0:0:0:0:0 with SMTP id i18csp997689ybl; Wed, 14 Aug 2019 09:08:13 -0700 (PDT) X-Google-Smtp-Source: APXvYqy9iDNV5YcVYR+i7cxithFG6e5+XNZA0sFICX67tuNDD0wO6SrBbgwZHwu4RspCrexrnwfz X-Received: by 2002:a17:90a:4485:: with SMTP id t5mr444825pjg.65.1565798893280; Wed, 14 Aug 2019 09:08:13 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1565798893; cv=none; d=google.com; s=arc-20160816; b=WCN34TFRc29CKgef6lGhCEs1s3Dss0S/2C6qGI8io3+6AdXb3Z2GiR8RcliGn2aJvj kbCJFtodD6DzyC/H0jSsScREHupNYvgAvcxk8ffqJAW0WbNXQi+oRb0e6Gnxm+/plg4M 933NK1OSgQB6iZg8s/dww1V7EpeWJT2igGN4IEVi7lGqg3auKtr2cC6GDKCqMx+3BBtN gfwpdU4hDqo+pYr/rWq9/6gbPyvCrw/kQQEYz9ncTwpCcrjzOBr8vj3YbYis5nZoI0Ic Q2XCk6WUKghH6E86PmWn1Q++j9GxN6QxS0R0wtMHLWvRmHnyOc2BLkzId1Ikg14EnBdI hPcw== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:sender:content-transfer-encoding:mime-version :references:in-reply-to:date:cc:to:from:subject:message-id; bh=MhHBQfLnZCZ+zzNiXYIIa/ai9IsbuRzu0CMeU2zx9kM=; b=ua5KH2SMCduciXC8a6UpFgPeKpGJzZwvUI+xGdxoH4x3/4GYLwNgFdY10V8+Np9LRm 6tInUx9XOxrYsm2JxsnrFiWBQIFxBOz7fvKlUOgemnFfnXBdpBj8e5J/Do+xYeFjLFIU OA01UiMUwGt1gXZhYHLomvGstttGajyyDT6PPY/+glaKuA4eqw7fwckLeFoBgHSqlOGS k2PsgjGepIdbP7PwD3a/eDA2ObRq0S4gvuZcQWd/Bm8LwdNsESmJ8DNskmHHU0BmJr4H AEaHCIhsoH1AmAtV0M4guYqfCVnt5aGbs6dRZfLM69VaLHjrRjUJmj3UWNZvhs5807iu IpRA== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=fail (p=NONE sp=NONE dis=NONE) header.from=intel.com Return-Path: Received: from vger.kernel.org (vger.kernel.org. [209.132.180.67]) by mx.google.com with ESMTP id 72si12310562pfx.268.2019.08.14.09.07.57; Wed, 14 Aug 2019 09:08:13 -0700 (PDT) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=fail (p=NONE sp=NONE dis=NONE) header.from=intel.com Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728286AbfHNQG7 (ORCPT + 99 others); Wed, 14 Aug 2019 12:06:59 -0400 Received: from mga17.intel.com ([192.55.52.151]:38992 "EHLO mga17.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726047AbfHNQG7 (ORCPT ); Wed, 14 Aug 2019 12:06:59 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga003.fm.intel.com ([10.253.24.29]) by fmsmga107.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 14 Aug 2019 09:06:58 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.64,385,1559545200"; d="scan'208";a="184358026" Received: from yyu32-desk1.sc.intel.com ([10.144.153.205]) by FMSMGA003.fm.intel.com with ESMTP; 14 Aug 2019 09:06:58 -0700 Message-ID: <84fc1b3bb2dbcf52ca79cb1141a431e087f082b5.camel@intel.com> Subject: Re: [PATCH v8 01/27] Documentation/x86: Add CET description From: Yu-cheng Yu To: Florian Weimer 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 , Borislav Petkov , Cyrill Gorcunov , Dave Hansen , Eugene Syromiatnikov , "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 Date: Wed, 14 Aug 2019 08:57:19 -0700 In-Reply-To: <87tvakgofi.fsf@oldenburg2.str.redhat.com> References: <20190813205225.12032-1-yu-cheng.yu@intel.com> <20190813205225.12032-2-yu-cheng.yu@intel.com> <87tvakgofi.fsf@oldenburg2.str.redhat.com> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.28.1-2 Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 2019-08-14 at 10:07 +0200, Florian Weimer wrote: > * Yu-cheng Yu: > > > +ENDBR > > + The compiler inserts an ENDBR at all valid branch targets. Any > > + CALL/JMP to a target without an ENDBR triggers a control > > + protection fault. > > Is this really correct? I think ENDBR is needed only for indirect > branch targets where the jump/call does not have a NOTRACK prefix. You are right. I will fix the wording. Yu-cheng