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=-4.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED autolearn=unavailable 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 E5310C10F00 for ; Tue, 12 Mar 2019 16:56:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id BDEDD2083D for ; Tue, 12 Mar 2019 16:56:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726712AbfCLQ46 (ORCPT ); Tue, 12 Mar 2019 12:56:58 -0400 Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:52072 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726272AbfCLQ46 (ORCPT ); Tue, 12 Mar 2019 12:56:58 -0400 Received: from pps.filterd (m0098393.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.27/8.16.0.27) with SMTP id x2CGtI3Y067355 for ; Tue, 12 Mar 2019 12:56:57 -0400 Received: from e06smtp03.uk.ibm.com (e06smtp03.uk.ibm.com [195.75.94.99]) by mx0a-001b2d01.pphosted.com with ESMTP id 2r6f4jed9g-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Tue, 12 Mar 2019 12:56:56 -0400 Received: from localhost by e06smtp03.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! 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Violators will be prosecuted; (version=TLSv1/SSLv3 cipher=AES256-GCM-SHA384 bits=256/256) Tue, 12 Mar 2019 16:56:50 -0000 Received: from d06av22.portsmouth.uk.ibm.com (d06av22.portsmouth.uk.ibm.com [9.149.105.58]) by b06cxnps4076.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id x2CGunP834144466 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Tue, 12 Mar 2019 16:56:49 GMT Received: from d06av22.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 8096D4C04A; Tue, 12 Mar 2019 16:56:49 +0000 (GMT) Received: from d06av22.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 5A7CB4C044; Tue, 12 Mar 2019 16:56:48 +0000 (GMT) Received: from localhost.localdomain (unknown [9.80.93.217]) by d06av22.portsmouth.uk.ibm.com (Postfix) with ESMTP; Tue, 12 Mar 2019 16:56:48 +0000 (GMT) Subject: Re: [PATCH] tpm: Make timeout logic simpler and more robust From: Mimi Zohar To: Jarkko Sakkinen , Calvin Owens Cc: Peter Huewe , Jason Gunthorpe , Arnd Bergmann , Greg Kroah-Hartman , linux-integrity@vger.kernel.org, linux-kernel@vger.kernel.org, kernel-team@fb.com Date: Tue, 12 Mar 2019 12:56:37 -0400 In-Reply-To: <20190312123632.GB9243@linux.intel.com> References: <358e89ed2b766d51b5f57abf31ab7a925ac63379.1552348123.git.calvinowens@fb.com> <20190312123632.GB9243@linux.intel.com> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.20.5 (3.20.5-1.fc24) Mime-Version: 1.0 Content-Transfer-Encoding: 7bit X-TM-AS-GCONF: 00 x-cbid: 19031216-0012-0000-0000-00000301BDE8 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 19031216-0013-0000-0000-00002138E02B Message-Id: <1552409797.24794.65.camel@linux.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:,, definitions=2019-03-12_09:,, signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 malwarescore=0 suspectscore=0 phishscore=0 bulkscore=0 spamscore=0 clxscore=1015 lowpriorityscore=0 mlxscore=0 impostorscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1810050000 definitions=main-1903120116 Sender: linux-integrity-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-integrity@vger.kernel.org On Tue, 2019-03-12 at 14:36 +0200, Jarkko Sakkinen wrote: > On Mon, Mar 11, 2019 at 04:54:04PM -0700, Calvin Owens wrote: > > We're having lots of problems with TPM commands timing out, and we're > > seeing these problems across lots of different hardware (both v1/v2). > > > > I instrumented the driver to collect latency data, but I wasn't able to > > find any specific timeout to fix: it seems like many of them are too > > aggressive. So I tried replacing all the timeout logic with a single > > universal long timeout, and found that makes our TPMs 100% reliable. > > > > Given that this timeout logic is very complex, problematic, and appears > > to serve no real purpose, I propose simply deleting all of it. > > > > Signed-off-by: Calvin Owens > > Have been thinking about this and I do agree. It has been like that > before my times with this subsystem so when I did the original TPM2 > patches I carried this logic albeit even at that point I did not get it. > Now that I've been maintaining for over three years I'm confident that > this the Right Thing to do. Please really consider this impact on IMA, before making this change. Mimi