From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751328AbdBAT0U (ORCPT ); Wed, 1 Feb 2017 14:26:20 -0500 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:40386 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751053AbdBAT0S (ORCPT ); Wed, 1 Feb 2017 14:26:18 -0500 Subject: Re: Fwd: Re: [tpmdd-devel] [PATCH v9 2/2] tpm: add securityfs support,for TPM 2.0 firmware event log To: Jarkko Sakkinen References: <588F09A2.4090502@linux.vnet.ibm.com> <20170131174659.b6njebycqzd5ur6f@intel.com> <5890DAFC.9030407@linux.vnet.ibm.com> <20170131205006.fljtxsy4s6lyhkvv@intel.com> <20170201144837.aenzg5cauzl2ofbt@intel.com> <20170201145430.s336rtavopx4k5r2@intel.com> Cc: Kenneth Goldman , "moderated list:TPM DEVICE DRIVER" , open list , linux-security-module@vger.kernel.org From: Nayna Date: Thu, 2 Feb 2017 00:55:41 +0530 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.6.0 MIME-Version: 1.0 In-Reply-To: <20170201145430.s336rtavopx4k5r2@intel.com> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit X-TM-AS-GCONF: 00 X-Content-Scanned: Fidelis XPS MAILER x-cbid: 17020119-0056-0000-0000-000002A4B8A2 X-IBM-SpamModules-Scores: X-IBM-SpamModules-Versions: BY=3.00006538; HX=3.00000240; KW=3.00000007; PH=3.00000004; SC=3.00000201; SDB=6.00815819; UDB=6.00398324; IPR=6.00593260; BA=6.00005108; NDR=6.00000001; ZLA=6.00000005; ZF=6.00000009; ZB=6.00000000; ZP=6.00000000; ZH=6.00000000; ZU=6.00000002; MB=3.00014140; XFM=3.00000011; UTC=2017-02-01 19:26:14 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 17020119-0057-0000-0000-000006D9BC8A Message-Id: <58923635.8060004@linux.vnet.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:,, definitions=2017-02-01_14:,, signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 spamscore=0 suspectscore=0 malwarescore=0 phishscore=0 adultscore=0 bulkscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1612050000 definitions=main-1702010191 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 02/01/2017 08:24 PM, Jarkko Sakkinen wrote: > On Wed, Feb 01, 2017 at 04:48:37PM +0200, Jarkko Sakkinen wrote: >> On Tue, Jan 31, 2017 at 10:50:06PM +0200, Jarkko Sakkinen wrote: >>> On Wed, Feb 01, 2017 at 12:14:12AM +0530, Nayna wrote: >>>>> I already sent my pull request to 4.11 and even today I found something >>>>> fishy. You declared a function local array by using a variable in "tpm: >>>>> enhance TPM 2.0 PCR extend to support multiple banks" (max_active_banks >>>>> or something). And the event log patches have just passed the review. >>>> >>>> Yes. I have checked using clang and it has passed the clang.. and I also >>>> verified there were no complains during build. >>> >>> What we can deduce from that is that they didn't expose the issue in >>> question. >>> >>> I found this by running sparse with make C=2 M=drives/char/tpm >>> >>>> What type of problem do you see ? >>> >>> It is disallowed to do stack allocation in the kernel code even if C >>> standard would allow it. Stack is scarce resource so you need to know >>> its usage at compile time. >>> >>> In this case you actually know the allocation because the value is not >>> changed during the course of the function but it is still bad. Probably >>> compiler will optimize it out. Still it is not a good practice. >>> >>>> Also, to understand, this is related to multi-bank patchset. I mean how does >>>> it affect for event log patchset ? >>> >>> Well in both cases these have landed fairly late but I asked from James >>> whether I'll have to postpone these to 4.12. >>> >>> Usually when I've sent my release pull request I do not want to make any >>> radical changes to the codebase because they always require extra QA and >>> thus take extra time. >> >> rc = tpm_transmit_cmd(chip, buf.data, tpm_buf_length(&buf), 0, 0, >> "attempting extend a PCR value"); >> >> This should be >> >> rc = tpm_transmit_cmd(chip, buf.data, PAGE_SIZE, 0, 0, >> "attempting extend a PCR value"); >> >> The second parameter is the size of the buffer, not length of the input >> data. >> >> /Jarkko > > As a sanity check can you test these commits and see if they still > work for you as I've done now some updates to them? Thanks. Thanks Jarkko, yes I tested for both multi-bank patches and event log. Its working fine. Thanks & Regards, - Nayna > > /Jarkko >