From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751799AbdKTXty (ORCPT ); Mon, 20 Nov 2017 18:49:54 -0500 Received: from mga01.intel.com ([192.55.52.88]:38319 "EHLO mga01.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751243AbdKTXtw (ORCPT ); Mon, 20 Nov 2017 18:49:52 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.44,430,1505804400"; d="scan'208";a="175932894" Date: Tue, 21 Nov 2017 01:49:47 +0200 From: Jarkko Sakkinen To: Jason Gunthorpe Cc: Guenter Roeck , Peter Huewe , Andrey Pronin , linux-integrity@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] tpm: Add explicit chip->ops locking for sysfs attributes. Message-ID: <20171120234947.zd5bekvqg5z5rp3i@linux.intel.com> References: <1510867501-9498-1-git-send-email-linux@roeck-us.net> <20171120221323.252ki4nmmrymnty6@linux.intel.com> <20171120224523.GA26294@roeck-us.net> <20171120231728.GR29075@ziepe.ca> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20171120231728.GR29075@ziepe.ca> Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo User-Agent: NeoMutt/20170609 (1.8.3) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Nov 20, 2017 at 04:17:28PM -0700, Jason Gunthorpe wrote: > On Mon, Nov 20, 2017 at 02:45:23PM -0800, Guenter Roeck wrote: > > > "tpm: Enable sysfs support for TPM2 devices > > > > Access to chip->ops on TPM2 devices requires an explicit lock, > > since the pointer is set to NULL in tpm_class_shutdown(). > > Implement that lock for sysfs access functions and enable sysfs > > support for TPM2 devices." > > Wait.. one of the reasons we let it go with no sysfs for so long was > because there was not many sysfs files that were compatible with tpm2? > > For TPM2 we have sort of had an API break of sorts from TPM1 in a > couple places around sysfs, and I would like to not re-introduce any > badly designed sysfs files for TPM2.. > > So.. When you apply this patch, what changes actually happen in the > sysfs directory? > > Jason Oops. I was too quick. This will cause all the TPM 1.x attributes added also for TPM 2.0. That's not a great idea. The tpm_dev_group should be only assigned for TPM 1.x devices. This commit should only enable addition of sysfs attributes for TPM 2.0 devices. /Jarkko