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=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 38799C2D0F2 for ; Wed, 1 Apr 2020 08:18:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 0E8DA2078B for ; Wed, 1 Apr 2020 08:18:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728236AbgDAISE (ORCPT ); Wed, 1 Apr 2020 04:18:04 -0400 Received: from mga07.intel.com ([134.134.136.100]:55050 "EHLO mga07.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727723AbgDAISE (ORCPT ); Wed, 1 Apr 2020 04:18:04 -0400 IronPort-SDR: mEk/JsUuTEg14Ss2mQgEBvBjGTX1SeQvW4d0cQLV+5F1rIJmIdLRvijOuyxEKHlXaysoQQjisU 64WTd5xwaGsA== X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga008.fm.intel.com ([10.253.24.58]) by orsmga105.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 01 Apr 2020 01:18:04 -0700 IronPort-SDR: Y+4ES8H4NZXxdy5wjQ+3KCt6qD+Cs27VGamnuqhhNZUp5Nl9eUIHB7yPNGe0jW8QhPsA6+IRl1 oTVnQCBOGAOg== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.72,331,1580803200"; d="scan'208";a="242160533" Received: from vikasjox-mobl.amr.corp.intel.com (HELO localhost) ([10.249.39.53]) by fmsmga008.fm.intel.com with ESMTP; 01 Apr 2020 01:18:00 -0700 Date: Wed, 1 Apr 2020 11:17:56 +0300 From: Jarkko Sakkinen To: Nathaniel McCallum Cc: Sean Christopherson , Cedric Xing , Jethro Beekman , Andy Lutomirski , linux-sgx@vger.kernel.org Subject: Re: [PATCH for_v29 v2 0/5] x86/sgx: Make vDSO callable from C Message-ID: <20200401081756.GA17325@linux.intel.com> References: <20200330180811.31381-1-sean.j.christopherson@intel.com> <20200330204839.GH1384380@linux.intel.com> <20200331115822.GD8295@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 Sender: linux-sgx-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-sgx@vger.kernel.org On Tue, Mar 31, 2020 at 09:40:24AM -0400, Nathaniel McCallum wrote: > On Tue, Mar 31, 2020 at 7:58 AM Jarkko Sakkinen > wrote: > > > > On Mon, Mar 30, 2020 at 05:42:29PM -0400, Nathaniel McCallum wrote: > > > On Mon, Mar 30, 2020 at 4:48 PM Jarkko Sakkinen > > > wrote: > > > > > > > > On Mon, Mar 30, 2020 at 11:08:06AM -0700, Sean Christopherson wrote: > > > > > Nathaniel pointed out that __vdso_sgx_enter_enclave() is tantalizingly > > > > > close to being callable from C (with caveats and a cooperative enclave). > > > > > The missing pieces are preserving %rbx and taking @leaf as a standard > > > > > parameter. > > > > > > > > > > v2: > > > > > - Rebase to Jarkko's latest master, commit 402fb35a477a, "docs: ...") > > > > > - Add CFI directive for RBX. [Cedric] > > > > > > > > I'm sorry for throwing stick's constantly but I think having a real > > > > ELF loader is for better. > > This statement seems like you are juxtaposing having > __vdso_sgx_enter_enclave() be potentially C-compatible with having an > ELF-loader. These are not incompabile. __vdso_sgx_enter_enclave() can > be C-callable *and* you can have an ELF loader. I'm not honestly sure what this is about but my comment was about heavy rebasing of the GIT tree as I rewrote the selftest last week. /Jarkko