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=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 0A702C4727E for ; Thu, 24 Sep 2020 21:55:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C934F20575 for ; Thu, 24 Sep 2020 21:55:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726749AbgIXVzd (ORCPT ); Thu, 24 Sep 2020 17:55:33 -0400 Received: from mga06.intel.com ([134.134.136.31]:45791 "EHLO mga06.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726626AbgIXVzd (ORCPT ); Thu, 24 Sep 2020 17:55:33 -0400 IronPort-SDR: mRpLz/4PSfGP47KhV+7PBYgvnoH1Ha4N40sMgvW5p/Lcw/ywWXnxCtr8elh07CXj/xRj5eDwMO uGy2FsM0Xh/g== X-IronPort-AV: E=McAfee;i="6000,8403,9754"; a="222950699" X-IronPort-AV: E=Sophos;i="5.77,299,1596524400"; d="scan'208";a="222950699" X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga006.fm.intel.com ([10.253.24.20]) by orsmga104.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 24 Sep 2020 14:55:31 -0700 IronPort-SDR: AkMp0QQSn+pgSPqyTMQhKVZ58RFR+QW7VRW8sy6EIH3jOoLPmPjl0mdG2T3tc2GcKG00Pi/lDX AOsRGmNSuX8w== X-IronPort-AV: E=Sophos;i="5.77,299,1596524400"; d="scan'208";a="511796388" Received: from yshmidtx-mobl1.ger.corp.intel.com (HELO localhost) ([10.252.63.233]) by fmsmga006-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 24 Sep 2020 14:55:25 -0700 Date: Fri, 25 Sep 2020 00:55:23 +0300 From: Jarkko Sakkinen To: Haitao Huang Cc: Sean Christopherson , Andy Lutomirski , X86 ML , linux-sgx@vger.kernel.org, LKML , Linux-MM , Andrew Morton , Matthew Wilcox , Jethro Beekman , Darren Kenny , Andy Shevchenko , asapek@google.com, Borislav Petkov , "Xing, Cedric" , chenalexchen@google.com, Conrad Parker , cyhanish@google.com, Dave Hansen , "Huang, Haitao" , Josh Triplett , "Huang, Kai" , "Svahn, Kai" , Keith Moyer , Christian Ludloff , Neil Horman , Nathaniel McCallum , Patrick Uiterwijk , David Rientjes , Thomas Gleixner , yaozhangx@google.com Subject: Re: [PATCH v38 10/24] mm: Add vm_ops->mprotect() Message-ID: <20200924215523.GA119995@linux.intel.com> References: <20200918235337.GA21189@sjchrist-ice> <20200921124946.GF6038@linux.intel.com> <20200921165758.GA24156@linux.intel.com> <20200921210736.GB58176@linux.intel.com> <20200921211849.GA25403@linux.intel.com> <20200922052957.GA97272@linux.intel.com> <20200922053515.GA97687@linux.intel.com> <20200922164301.GB30874@linux.intel.com> <20200923135056.GD5160@linux.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Sep 24, 2020 at 02:11:37PM -0500, Haitao Huang wrote: > > For me this has caused months of confusion and misunderstanding of this > > feature. I only recently realized that "oh, right, we invented this". > > > > They are contrived scenarios enough that they should be considered when > > the workloads hit. > > > > Either we fully support noexec or not at all. Any "partial" thing is a > > two edged sword: it can bring some robustness with the price of > > complexity and possible unknown uknown scenarios where they might become > > API issue. > > > > I rather think later on how to extend API in some way to enable such > > contrivid scenarios rather than worrying about how this could be abused. > > > > The whole SGX is complex beast already so lets not add any extra when > > there is no a hard requirement to do so. > > > > I'll categorically deny noexec in the next patch set version. > > > > /Jarkko > > There are use cases supported currently in which enclave binary is received > via IPC/RPC and held in buffers before EADD. Denying noexec altogether would > break those, right? I do not see why data cannot be provided at run-time. AFAIK, it is not different from executables how this works when it comes to noexec. /Jarkko