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 24E94C433FF for ; Sat, 10 Aug 2019 11:22:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id F12062166E for ; Sat, 10 Aug 2019 11:22:24 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725888AbfHJLWY (ORCPT ); Sat, 10 Aug 2019 07:22:24 -0400 Received: from mga09.intel.com ([134.134.136.24]:21051 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725862AbfHJLWY (ORCPT ); Sat, 10 Aug 2019 07:22:24 -0400 X-Amp-Result: UNSCANNABLE X-Amp-File-Uploaded: False Received: from orsmga007.jf.intel.com ([10.7.209.58]) by orsmga102.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 10 Aug 2019 04:22:23 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.64,369,1559545200"; d="scan'208";a="166243962" Received: from agudipat-mobl.ger.corp.intel.com (HELO localhost) ([10.249.36.164]) by orsmga007.jf.intel.com with ESMTP; 10 Aug 2019 04:22:21 -0700 Date: Sat, 10 Aug 2019 14:22:16 +0300 From: Jarkko Sakkinen To: Sean Christopherson Cc: linux-sgx@vger.kernel.org Subject: Re: [PATCH for_v22] selftests/x86/sgx: Ensure SECS base (ELRANGE) is naturally aligned Message-ID: <20190810112216.u2dolvtkv62dyeno@linux.intel.com> References: <20190810003051.15712-1-sean.j.christopherson@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190810003051.15712-1-sean.j.christopherson@intel.com> Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo User-Agent: NeoMutt/20180716 Sender: linux-sgx-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-sgx@vger.kernel.org On Fri, Aug 09, 2019 at 05:30:51PM -0700, Sean Christopherson wrote: > Manually align ELRANGE now that the kernel doesn't automatically do so > for SGX mappings. To guarantee mmap() returns a region that can be > naturally aligned, temporarily map 2x the enclave size and do fancy > arithmetic to naturally align the base. > > Signed-off-by: Sean Christopherson Thank you. I fine-tuned the calculations a bit: area = mmap(NULL, secs->size * 2, PROT_NONE, MAP_SHARED, dev_fd, 0); if (area == MAP_FAILED) { perror("mmap"); return false; } secs->base = ((uint64_t)area + secs->size - 1) & ~(secs->size - 1); munmap(area, secs->base - (uint64_t)area); munmap((void *)(secs->base + secs->size), (uint64_t)area + secs->size - secs->base); /Jarkko