From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757440AbdADMoO (ORCPT ); Wed, 4 Jan 2017 07:44:14 -0500 Received: from mga04.intel.com ([192.55.52.120]:42665 "EHLO mga04.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751221AbdADMoA (ORCPT ); Wed, 4 Jan 2017 07:44:00 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.33,459,1477983600"; d="scan'208";a="1089781679" Date: Wed, 4 Jan 2017 14:43:54 +0200 From: Jarkko Sakkinen To: Jason Gunthorpe Cc: tpmdd-devel@lists.sourceforge.net, linux-security-module@vger.kernel.org, Peter Huewe , Marcel Selhorst , open list Subject: Re: [PATCH RFC 4/4] tpm: add the infrastructure for TPM space for TPM 2.0 Message-ID: <20170104124354.wga6lngg4gkpeefv@intel.com> References: <20170102132213.22880-1-jarkko.sakkinen@linux.intel.com> <20170102132213.22880-5-jarkko.sakkinen@linux.intel.com> <20170102210953.GB5544@obsidianresearch.com> <20170103003730.he32vl55kkta2q64@intel.com> <20170103184627.GA26706@obsidianresearch.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20170103184627.GA26706@obsidianresearch.com> Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo User-Agent: Mutt/1.6.2-neo (2016-08-21) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Jan 03, 2017 at 11:46:27AM -0700, Jason Gunthorpe wrote: > On Tue, Jan 03, 2017 at 02:37:30AM +0200, Jarkko Sakkinen wrote: > > On Mon, Jan 02, 2017 at 02:09:53PM -0700, Jason Gunthorpe wrote: > > > On Mon, Jan 02, 2017 at 03:22:10PM +0200, Jarkko Sakkinen wrote: > > > > Added a ioctl for creating a TPM space. The space is isolated from the > > > > other users of the TPM. Only a process holding the file with the handle > > > > can access the objects and only objects that are created through that > > > > file handle can be accessed. > > > > > > I don't understand this comment. /dev/tpmX is forced to be > > > single-process-open, so how can there ever be more than 1 FD for it? > > > > > > Since the space is tied to that single fd these patches just create a > > > way for the single user-space process to auto-cleanup if it crashes? > > > > > > Is that the entire intent of this design? I guess it is OK as a > > > stepping point.. > > > > is_open is cleared in tpm_ioc_new_space. > > That is no good, it is racy if the intention is to use multiple > clients, and any single client that doesn't support the new API blocks > all access. Luckily this will be implicitly fixed with a separate device file in the non-RFC patch set :-) > Jason /Jarkko