From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752227AbeCJLVY (ORCPT ); Sat, 10 Mar 2018 06:21:24 -0500 Received: from mga09.intel.com ([134.134.136.24]:41379 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751974AbeCJLVU (ORCPT ); Sat, 10 Mar 2018 06:21:20 -0500 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.47,451,1515484800"; d="scan'208";a="37593919" Message-ID: Subject: Re: [PATCH 3/5 V2] tpm2: add longer timeouts for creation commands. From: Jarkko Sakkinen To: "Winkler, Tomas" , Jason Gunthorpe Cc: "Usyskin, Alexander" , "linux-integrity@vger.kernel.org" , "linux-security-module@vger.kernel.org" , "linux-kernel@vger.kernel.org" Date: Sat, 10 Mar 2018 13:21:16 +0200 In-Reply-To: <5B8DA87D05A7694D9FA63FD143655C1B9422F4C1@hasmsx108.ger.corp.intel.com> References: <20180306092503.11568-1-tomas.winkler@intel.com> <20180306092503.11568-4-tomas.winkler@intel.com> <1520339005.3779.3.camel@linux.intel.com> <5B8DA87D05A7694D9FA63FD143655C1B9422F4C1@hasmsx108.ger.corp.intel.com> Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.27.90-1 Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 2018-03-06 at 15:19 +0000, Winkler, Tomas wrote: > > On Tue, 2018-03-06 at 11:25 +0200, Tomas Winkler wrote: > > > TPM2_CC_Create(0x153) and TPM2_CC_CreatePrimary (0x131) involve > > > generation of crypto keys which can be a computationally intensive task. > > > The timeout is set to 3min. > > > Rather than increasing default timeout a new constant is added, to not > > > stall for too long on regular commands failures. > > > > > > Signed-off-by: Tomas Winkler > > > > Why are you radically chaging the default timeout? The commit message > > does not tell anything about that change. > > > > Let me, recheck but it should be same value just converted to msecs. > > > Why couldn't we just have two timeouts: one default and one long that > > would be at least as long as the longest timeout defined in the spec? > > I've tried to explain it in the commit message but apparently has failed. > > We have a default or undefined which should be the same as it was unless I did > some silly mistake in conversion to msecs (will check), ass all others are in > msecs. > It was 2 min = 2 * 60 * HZ (in jiffies) which would be msecs_to_jiffies(2 * 60 > * 1000 = 120000) > TPM2_DURATION_DEFAULT = 120000 Aah, of course :-) The problem was that I had somehow a blid spot with seeing the msec_to_jiffies() conversion. TPM_NUM_DURATIONS would a better name than TPM_DURATION_MAX because TPM_DURATION_MAX is easy to confuse with TPM_DURATION_* constants. /Jarkko