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=-2.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_2 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 46B3AC433FF for ; Wed, 14 Aug 2019 16:30:06 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 1214220665 for ; Wed, 14 Aug 2019 16:30:05 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 1214220665 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=intel.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id AF98E6B0003; Wed, 14 Aug 2019 12:30:04 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id AA9B96B0005; Wed, 14 Aug 2019 12:30:04 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 997856B000A; Wed, 14 Aug 2019 12:30:04 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0167.hostedemail.com [216.40.44.167]) by kanga.kvack.org (Postfix) with ESMTP id 7B1826B0003 for ; Wed, 14 Aug 2019 12:30:04 -0400 (EDT) Received: from smtpin04.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with SMTP id 265F0181AC9AE for ; Wed, 14 Aug 2019 16:30:04 +0000 (UTC) X-FDA: 75821570328.04.show25_1d7c56ad86a44 X-HE-Tag: show25_1d7c56ad86a44 X-Filterd-Recvd-Size: 2638 Received: from mga12.intel.com (mga12.intel.com [192.55.52.136]) by imf11.hostedemail.com (Postfix) with ESMTP for ; Wed, 14 Aug 2019 16:30:01 +0000 (UTC) X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga007.fm.intel.com ([10.253.24.52]) by fmsmga106.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 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: 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