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=-5.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_SANE_1 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 6BCA7CA9EA1 for ; Fri, 18 Oct 2019 09:57:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 498C0222BD for ; Fri, 18 Oct 2019 09:57:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2405013AbfJRJ5R (ORCPT ); Fri, 18 Oct 2019 05:57:17 -0400 Received: from mga07.intel.com ([134.134.136.100]:38647 "EHLO mga07.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2389081AbfJRJ5Q (ORCPT ); Fri, 18 Oct 2019 05:57:16 -0400 X-Amp-Result: UNKNOWN X-Amp-Original-Verdict: FILE UNKNOWN X-Amp-File-Uploaded: False Received: from fmsmga007.fm.intel.com ([10.253.24.52]) by orsmga105.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 18 Oct 2019 02:57:15 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.67,311,1566889200"; d="scan'208";a="196164138" Received: from glas-mobl.ger.corp.intel.com (HELO localhost) ([10.252.17.198]) by fmsmga007.fm.intel.com with ESMTP; 18 Oct 2019 02:57:14 -0700 Date: Fri, 18 Oct 2019 12:57:13 +0300 From: Jarkko Sakkinen To: Sean Christopherson Cc: linux-sgx@vger.kernel.org Subject: Re: [PATCH for_v23 v3 01/12] x86/sgx: Pass EADD the kernel's virtual address for the source page Message-ID: <20191018095713.GA4835@linux.intel.com> References: <20191016183745.8226-1-sean.j.christopherson@intel.com> <20191016183745.8226-2-sean.j.christopherson@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20191016183745.8226-2-sean.j.christopherson@intel.com> Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-sgx-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-sgx@vger.kernel.org On Wed, Oct 16, 2019 at 11:37:34AM -0700, Sean Christopherson wrote: > Use the kernel's virtual address to reference the source page when > EADDing a page to the enclave. gup() "does not guarantee that the page > exists in the user mappings", i.e. EADD can still fault and deadlock > due to mmap_sem contention if it consumes the userspace address. > > Signed-off-by: Sean Christopherson > + kunmap_atomic((void *)pginfo.contents); Remark: if not casted first to unsigned long, it will give a warning on 32-bit build. /Jarkko