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=-5.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE, SPF_PASS,USER_AGENT_SANE_1 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 BBDA3C433C1 for ; Fri, 19 Mar 2021 15:17:07 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 5B7E761923 for ; Fri, 19 Mar 2021 15:17:07 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 5B7E761923 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 B1E6D6B007D; Fri, 19 Mar 2021 11:17:06 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id AF5126B007E; Fri, 19 Mar 2021 11:17:06 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 9BD0D8D0001; Fri, 19 Mar 2021 11:17:06 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0088.hostedemail.com [216.40.44.88]) by kanga.kvack.org (Postfix) with ESMTP id 832CF6B007D for ; Fri, 19 Mar 2021 11:17:06 -0400 (EDT) Received: from smtpin11.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay04.hostedemail.com (Postfix) with ESMTP id 3442D2492 for ; Fri, 19 Mar 2021 15:17:06 +0000 (UTC) X-FDA: 77936976852.11.80DC264 Received: from mga03.intel.com (mga03.intel.com [134.134.136.65]) by imf19.hostedemail.com (Postfix) with ESMTP id 0274C9001159 for ; Fri, 19 Mar 2021 15:17:00 +0000 (UTC) IronPort-SDR: a4Oi67kDSCtFJWmKT9mO3mByCcslG5wfh3Iw2M3hoUbQsbHoC/HO7kGMkGIdchOFc0RVbgDXED T24hgqJQW/CA== X-IronPort-AV: E=McAfee;i="6000,8403,9928"; a="189946896" X-IronPort-AV: E=Sophos;i="5.81,262,1610438400"; d="scan'208";a="189946896" Received: from orsmga001.jf.intel.com ([10.7.209.18]) by orsmga103.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 19 Mar 2021 08:15:35 -0700 IronPort-SDR: xqCql09qCKZCcyUj9naOiIO6KtbsHf2bUgXg7u6ReJH6uqO28nq/GVC31qrzwCLql1HWkoZgk8 EoNy+lU/ZQMQ== X-IronPort-AV: E=Sophos;i="5.81,262,1610438400"; d="scan'208";a="450895952" Received: from yyu32-mobl1.amr.corp.intel.com (HELO [10.209.156.180]) ([10.209.156.180]) by orsmga001-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 19 Mar 2021 08:15:33 -0700 Subject: Re: [PATCH v23 22/28] x86/cet/shstk: User-mode shadow stack support To: Borislav Petkov 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 , 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 References: <20210316151054.5405-1-yu-cheng.yu@intel.com> <20210316151054.5405-23-yu-cheng.yu@intel.com> <20210318123215.GE19570@zn.tnic> <20210319092806.GB6251@zn.tnic> From: "Yu, Yu-cheng" Message-ID: <3144b030-0f90-717b-b373-2d0b346010c8@intel.com> Date: Fri, 19 Mar 2021 08:15:33 -0700 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:78.0) Gecko/20100101 Thunderbird/78.8.0 MIME-Version: 1.0 In-Reply-To: <20210319092806.GB6251@zn.tnic> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit X-Rspamd-Server: rspam04 X-Rspamd-Queue-Id: 0274C9001159 X-Stat-Signature: jj4j4juh7kwamgc6nb3e3dp3j895xfrx Received-SPF: none (intel.com>: No applicable sender policy available) receiver=imf19; identity=mailfrom; envelope-from=""; helo=mga03.intel.com; client-ip=134.134.136.65 X-HE-DKIM-Result: none/none X-HE-Tag: 1616167020-739261 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 3/19/2021 2:28 AM, Borislav Petkov wrote: > On Thu, Mar 18, 2021 at 12:05:58PM -0700, Yu, Yu-cheng wrote: >> Maybe I would add comments here. > > Yap. > > Also, looking forward in the set, I see prctl_set() and that is also > done on current so should be ok. > > In any case, yes, documenting the assumptions and expectations wrt > current here is a good idea. > >> If vm_munmap() returns -EINTR, mmap_lock is held by something else. That >> lock should not be held forever. For other types of error, the loop stops. > > Ok I guess. The subsequent WARN_ON_ONCE() looks weird too but that > should not fire, right? :) > > Thx. > That should not fire. Yu-cheng