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=-6.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY,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 D0040C433E1 for ; Tue, 18 Aug 2020 16:20:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B236020866 for ; Tue, 18 Aug 2020 16:20:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727072AbgHRQUF (ORCPT ); Tue, 18 Aug 2020 12:20:05 -0400 Received: from mga11.intel.com ([192.55.52.93]:39629 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726934AbgHRQT6 (ORCPT ); Tue, 18 Aug 2020 12:19:58 -0400 IronPort-SDR: 9k/8ZpUFtjRyXQcNGXQU/AIaPusIxqU1ZWLzb85RTZVofp3Y4/M4k9paklKOAzVYsgl6mtY1Bh iZWMjvslLO9g== X-IronPort-AV: E=McAfee;i="6000,8403,9716"; a="152571180" X-IronPort-AV: E=Sophos;i="5.76,328,1592895600"; d="scan'208";a="152571180" X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga003.fm.intel.com ([10.253.24.29]) by fmsmga102.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 18 Aug 2020 09:19:57 -0700 IronPort-SDR: 16LsjAxapJmvf6CHam0ZL48+HlbamZHLkVbCa/bbXHIUJI1J7myn2lN7VQ++WYg8T6ApdRDfOr TTW8yYEk0V0A== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.76,328,1592895600"; d="scan'208";a="334412523" Received: from ribnhajh-mobl.ger.corp.intel.com (HELO localhost) ([10.249.47.113]) by FMSMGA003.fm.intel.com with ESMTP; 18 Aug 2020 09:19:56 -0700 Date: Tue, 18 Aug 2020 19:19:55 +0300 From: Jarkko Sakkinen To: James Bottomley Cc: linux-integrity@vger.kernel.org, Mimi Zohar Subject: Re: [PATCH v4 1/1] tpm: add sysfs exports for all banks of PCR registers Message-ID: <20200818161955.GD137138@linux.intel.com> References: <20200817213506.4474-1-James.Bottomley@HansenPartnership.com> <20200817213506.4474-2-James.Bottomley@HansenPartnership.com> <20200818161207.GC137138@linux.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200818161207.GC137138@linux.intel.com> Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo Sender: linux-integrity-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-integrity@vger.kernel.org On Tue, Aug 18, 2020 at 07:12:09PM +0300, Jarkko Sakkinen wrote: > On Mon, Aug 17, 2020 at 02:35:06PM -0700, James Bottomley wrote: > > Create sysfs per hash groups with 24 PCR files in them one group, > > named pcr-, for each agile hash of the TPM. The files are > > plugged in to a PCR read function which is TPM version agnostic, so > > this works also for TPM 1.2 but the hash is only sha1 in that case. > > > > Note: the macros used to create the hashes emit spurious checkpatch > > warnings. Do not try to "fix" them as checkpatch recommends, otherwise > > they'll break. > > > > Signed-off-by: James Bottomley > > Reviewed-by: Jerry Snitselaar > > Tested-by: Thiago Jung Bauermann > > I have hard time understanding why this is required. > > You can grab the information through /dev/tpm0 just fine. I just think it is principally wrong to add sysfs files if they don't have any measurable value other than perhaps some convenience. It is trival to write only a libc dependent program that outputs PCRs. I think this is essentially an user space problem that is getting sorted out with kernel code. /Jarkko