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=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS autolearn=ham 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 52D94C31E49 for ; Wed, 19 Jun 2019 12:56:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 24937208CB for ; Wed, 19 Jun 2019 12:56:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727882AbfFSM4j (ORCPT ); Wed, 19 Jun 2019 08:56:39 -0400 Received: from mga03.intel.com ([134.134.136.65]:1849 "EHLO mga03.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727244AbfFSM4i (ORCPT ); Wed, 19 Jun 2019 08:56:38 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga006.fm.intel.com ([10.253.24.20]) by orsmga103.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 19 Jun 2019 05:56:38 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.63,392,1557212400"; d="scan'208";a="358604522" Received: from stephanf-mobl2.ger.corp.intel.com ([10.252.34.117]) by fmsmga006.fm.intel.com with ESMTP; 19 Jun 2019 05:56:32 -0700 Message-ID: <40eea889978d8376ef8afc8a50634d73bcfa79ae.camel@linux.intel.com> Subject: Re: [RFC PATCH v3 01/12] x86/sgx: Add mm to enclave at mmap() From: Jarkko Sakkinen To: Sean Christopherson Cc: linux-sgx@vger.kernel.org, Dave Hansen , Cedric Xing , Andy Lutomirski , Jethro Beekman , "Dr . Greg Wettstein" , Stephen Smalley Date: Wed, 19 Jun 2019 15:56:28 +0300 In-Reply-To: <20190617222438.2080-2-sean.j.christopherson@intel.com> References: <20190617222438.2080-1-sean.j.christopherson@intel.com> <20190617222438.2080-2-sean.j.christopherson@intel.com> Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo Content-Type: text/plain; charset="UTF-8" User-Agent: Evolution 3.32.1-2 MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-sgx-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-sgx@vger.kernel.org On Mon, 2019-06-17 at 15:24 -0700, Sean Christopherson wrote: > The enclave mm tracking is currently broken: > > - Adding current->mm during ECREATE is wrong as there is no guarantee > that the current process has mmap()'d the enclave, i.e. there may > never be an associated sgx_vma_close() to drop the encl_mm. > > - Adding mm's at sgx_vma_open() is wrong as vm_ops->open is called > only when splitting or duplicating a vma. If userspace performs a > single mmap() on the enclave then SGX will fail to track the mm. > This bug is partially hidden by tracking current->mm at ECREATE. > > Rework the tracking to get/add the mm at mmap(). A side effect of the > bug fix is that sgx_vma_{open,close}() should never encounter a vma with > an associated enclave and no associated encl_mm, i.e. WARN if an encl_mm > cannot be found in either condition. > > Change the WARN() on a non-empty mm_list to a WARN_ONCE(). The warning > will fire over and over (and over) if the mm tracking is broken, which > hampers debug/triage far more than it helps. > > Signed-off-by: Sean Christopherson > --- > arch/x86/kernel/cpu/sgx/driver/ioctl.c | 14 ---------- > arch/x86/kernel/cpu/sgx/driver/main.c | 26 ++++++++++++++++++ > arch/x86/kernel/cpu/sgx/encl.c | 38 +++++--------------------- > arch/x86/kernel/cpu/sgx/encl.h | 4 +-- > 4 files changed, 35 insertions(+), 47 deletions(-) BTW, sgx_encl_mm is a bit confusing name (which I made) to begin with. It clues as it was a some kind of 1:1 association with the process, which it isn't. Could you update the patch and rename it as sgx_encl_mapping? After that I'm happy to merge. /Jarkko