Received: by 2002:a25:8b12:0:0:0:0:0 with SMTP id i18csp1024736ybl; Wed, 14 Aug 2019 09:32:21 -0700 (PDT) X-Google-Smtp-Source: APXvYqxGVOavSU8d7ACDhBceaEYniQNsOcrTt1+/XXheBhoaGcbOCiLnvBc2vXwco09I6qg52yoy X-Received: by 2002:a17:90a:d795:: with SMTP id z21mr566129pju.43.1565800341703; Wed, 14 Aug 2019 09:32:21 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1565800341; cv=none; d=google.com; s=arc-20160816; b=ox1CKSJIp+k9SZoRw9G+r8dFFLYFkHAIO1hXEcpukUY3AxcNV5BRJNGmN+J/7vepg3 klE7WZpkER17qg6/9rVsLXQHCIP6IrK+7GGoYTe6UudKIHGHReDpYBQLJh7+tUbRrhQA IlLq949Mz6RhwrFKxBMTRWOKzQv2DKZLDjADBklxweiNlhHRjMxKjBAXJxen3JFogGAI VIwd1Cp548vrys2mvrnnWXxG0DqAbDl84MOD5fx+aHxQVm+5F9KCVpqiQ1azLNVODcne ZBQqiVG0ty3xzQEEzZNqsEdlZ9Go0X6her75kErU4ciymzsTtPnfDDIvPBq6vLQPjkas wtoQ== 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:to:from:subject:message-id; bh=6Rf746ZC4aQhJKCW2P8equSR3k/jaFFts6zqWzoIGjo=; b=okMgQPuCmkG2oJ5aJ//Yz3Mvi54+8AX1HjKEuB0iKRSuheOP3qvW1CXt0oyjg37fZx ApHwd17hVArkuvk/GjCVJ1mK6hokp9nLE5+URsD7Xpk91hDAJnaTeYo4iobI+jp97aYk lCTr+yKDJWdgecZWnr8lTNd9K6X0SXSPDD/wMcDEY07lJ9Ycg82kyTir/rygqVRREghG 67HLt94yPx/Hvh624DU3go5AZHdrcYNTT9ahgOyRrsJYYuWbj84Ikf63RT1kkJoqSVUQ CJI8OaFnKFSlcjfv2S08VV/zLgiEznZsanMxXEHdKiU7Q4v06MkdYy0yfvLOF0jz8PRY 6lWw== 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 em12si139885pjb.25.2019.08.14.09.32.04; Wed, 14 Aug 2019 09:32:21 -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 S1727937AbfHNQaB (ORCPT + 99 others); Wed, 14 Aug 2019 12:30:01 -0400 Received: from mga05.intel.com ([192.55.52.43]:19771 "EHLO mga05.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726047AbfHNQaB (ORCPT ); Wed, 14 Aug 2019 12:30:01 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga007.fm.intel.com ([10.253.24.52]) by fmsmga105.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 14 Aug 2019 09:30:00 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.64,385,1559545200"; d="scan'208";a="178211198" Received: from yyu32-desk1.sc.intel.com ([10.144.153.205]) by fmsmga007.fm.intel.com with ESMTP; 14 Aug 2019 09:30:00 -0700 Message-ID: <699fe0a2c2331af0d45a3516d9422d5ed5b59a99.camel@intel.com> Subject: Re: [PATCH v8 09/27] mm/mmap: Prevent Shadow Stack VMA merges From: Yu-cheng Yu To: Dave Hansen , 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 Date: Wed, 14 Aug 2019 09:20:21 -0700 In-Reply-To: <5ba3d1b3-5587-e7dd-b9de-9a954172d31f@intel.com> References: <20190813205225.12032-1-yu-cheng.yu@intel.com> <20190813205225.12032-10-yu-cheng.yu@intel.com> <5ba3d1b3-5587-e7dd-b9de-9a954172d31f@intel.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 Tue, 2019-08-13 at 15:34 -0700, Dave Hansen wrote: > On 8/13/19 1:52 PM, Yu-cheng Yu wrote: > > To prevent function call/return spills into the next shadow stack > > area, do not merge shadow stack areas. > > How does this prevent call/return spills? It does not. I will fix the description. Yu-cheng