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=-2.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_MUTT autolearn=unavailable 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 99D13C28CC6 for ; Wed, 5 Jun 2019 14:08:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6A5D3206C3 for ; Wed, 5 Jun 2019 14:08:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728353AbfFEOIQ (ORCPT ); Wed, 5 Jun 2019 10:08:16 -0400 Received: from mga12.intel.com ([192.55.52.136]:38356 "EHLO mga12.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726442AbfFEOIQ (ORCPT ); Wed, 5 Jun 2019 10:08:16 -0400 X-Amp-Result: UNKNOWN X-Amp-Original-Verdict: FILE UNKNOWN X-Amp-File-Uploaded: False Received: from orsmga007.jf.intel.com ([10.7.209.58]) by fmsmga106.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 05 Jun 2019 07:08:15 -0700 X-ExtLoop1: 1 Received: from sjchrist-coffee.jf.intel.com (HELO linux.intel.com) ([10.54.74.36]) by orsmga007.jf.intel.com with ESMTP; 05 Jun 2019 07:08:15 -0700 Date: Wed, 5 Jun 2019 07:08:15 -0700 From: Sean Christopherson To: "Xing, Cedric" Cc: Andy Lutomirski , Jarkko Sakkinen , Stephen Smalley , James Morris , "Serge E . Hallyn" , LSM List , Paul Moore , Eric Paris , "selinux@vger.kernel.org" , Jethro Beekman , "Hansen, Dave" , Thomas Gleixner , Linus Torvalds , LKML , X86 ML , "linux-sgx@vger.kernel.org" , Andrew Morton , "nhorman@redhat.com" , "npmccallum@redhat.com" , "Ayoun, Serge" , "Katz-zamir, Shay" , "Huang, Haitao" , Andy Shevchenko , "Svahn, Kai" , Borislav Petkov , Josh Triplett , "Huang, Kai" , David Rientjes , "Roberts, William C" , "Tricca, Philip B" Subject: Re: [RFC PATCH 2/9] x86/sgx: Do not naturally align MAP_FIXED address Message-ID: <20190605140815.GA26328@linux.intel.com> References: <20190531233159.30992-1-sean.j.christopherson@intel.com> <20190531233159.30992-3-sean.j.christopherson@intel.com> <20190604114951.GC30594@linux.intel.com> <960B34DE67B9E140824F1DCDEC400C0F654EDBDE@ORSMSX116.amr.corp.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <960B34DE67B9E140824F1DCDEC400C0F654EDBDE@ORSMSX116.amr.corp.intel.com> User-Agent: Mutt/1.5.24 (2015-08-30) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Jun 04, 2019 at 03:10:22PM -0700, Xing, Cedric wrote: > A bit off topic here. This mmap()/mprotect() discussion reminds me a question > (guess for Jarkko): Now that vma->vm_file->private_data keeps a pointer to > the enclave, why do we store it again in vma->vm_private? It isn't a big deal > but non-NULL vm_private does prevent mprotect() from merging adjacent VMAs. vma->vm_ops->close also prevents merging, and we need that to refcount the enclave and mm. We also rely on nullifying vma->vm_private_data in the unlikely event that adding a new mm to the enclave fails on kzalloc().