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=-2.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_2 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 64AA4C43603 for ; Fri, 13 Dec 2019 02:33:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4028A21655 for ; Fri, 13 Dec 2019 02:33:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731720AbfLMCdH (ORCPT ); Thu, 12 Dec 2019 21:33:07 -0500 Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:52956 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731311AbfLMCdG (ORCPT ); Thu, 12 Dec 2019 21:33:06 -0500 Received: from pps.filterd (m0098393.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.42/8.16.0.42) with SMTP id xBD2WPQZ076880 for ; Thu, 12 Dec 2019 21:33:05 -0500 Received: from e06smtp05.uk.ibm.com (e06smtp05.uk.ibm.com [195.75.94.101]) by mx0a-001b2d01.pphosted.com with ESMTP id 2wuq3wv2kc-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Thu, 12 Dec 2019 21:33:05 -0500 Received: from localhost by e06smtp05.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Fri, 13 Dec 2019 02:33:03 -0000 Received: from b06cxnps4075.portsmouth.uk.ibm.com (9.149.109.197) by e06smtp05.uk.ibm.com (192.168.101.135) with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted; (version=TLSv1/SSLv3 cipher=AES256-GCM-SHA384 bits=256/256) Fri, 13 Dec 2019 02:33:00 -0000 Received: from d06av22.portsmouth.uk.ibm.com (d06av22.portsmouth.uk.ibm.com [9.149.105.58]) by b06cxnps4075.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id xBD2Wxjf50528344 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Fri, 13 Dec 2019 02:32:59 GMT Received: from d06av22.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 248064C044; Fri, 13 Dec 2019 02:32:59 +0000 (GMT) Received: from d06av22.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id F04E34C040; Fri, 13 Dec 2019 02:32:57 +0000 (GMT) Received: from localhost.localdomain (unknown [9.80.206.100]) by d06av22.portsmouth.uk.ibm.com (Postfix) with ESMTP; Fri, 13 Dec 2019 02:32:57 +0000 (GMT) Subject: Re: [PATCH v3 1/2] IMA: Define workqueue for early boot "key" measurements From: Mimi Zohar To: Lakshmi Ramasubramanian , linux-integrity@vger.kernel.org Cc: eric.snowberg@oracle.com, dhowells@redhat.com, mathew.j.martineau@linux.intel.com, matthewgarrett@google.com, sashal@kernel.org, jamorris@linux.microsoft.com, linux-kernel@vger.kernel.org, keyrings@vger.kernel.org Date: Thu, 12 Dec 2019 21:32:57 -0500 In-Reply-To: <6e0dad33-66f9-4807-d08d-ff30396cec5e@linux.microsoft.com> References: <20191213004250.21132-1-nramas@linux.microsoft.com> <20191213004250.21132-2-nramas@linux.microsoft.com> <1576202134.4579.189.camel@linux.ibm.com> <6e0dad33-66f9-4807-d08d-ff30396cec5e@linux.microsoft.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: 19121302-0020-0000-0000-00000397A111 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 19121302-0021-0000-0000-000021EEACE1 Message-Id: <1576204377.4579.206.camel@linux.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.95,18.0.572 definitions=2019-12-12_08:2019-12-12,2019-12-12 signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 mlxscore=0 clxscore=1015 mlxlogscore=999 impostorscore=0 suspectscore=0 bulkscore=0 adultscore=0 lowpriorityscore=0 spamscore=0 priorityscore=1501 malwarescore=0 phishscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-1910280000 definitions=main-1912130020 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 2019-12-12 at 17:59 -0800, Lakshmi Ramasubramanian wrote: > On 12/12/19 5:55 PM, Mimi Zohar wrote: > >> +/* > >> + * ima_process_queued_keys() - process keys queued for measurement > >> + * > >> + * This function sets ima_process_keys to true and processes queued keys. > >> + * From here on keys will be processed right away (not queued). > >> + */ > >> +void ima_process_queued_keys(void) > >> +{ > >> + struct ima_key_entry *entry, *tmp; > >> + LIST_HEAD(temp_ima_keys); > >> + > >> + if (ima_process_keys) > >> + return; > >> + > >> + /* > >> + * To avoid holding the mutex when processing queued keys, > >> + * transfer the queued keys with the mutex held to a temp list, > >> + * release the mutex, and then process the queued keys from > >> + * the temp list. > >> + * > >> + * Since ima_process_keys is set to true, any new key will be > >> + * processed immediately and not be queued. > >> + */ > >> + INIT_LIST_HEAD(&temp_ima_keys); > >> + > >> + mutex_lock(&ima_keys_mutex); > > > > Don't you need a test here, before setting ima_process_keys? > > > > if (ima_process_keys) > > return; > > > > Mimi > > That check is done before the comment - at the start of > ima_process_queued_keys(). The first test prevents taking the mutex unnecessarily. Mimi > +void ima_process_queued_keys(void) > +{ > + struct ima_key_entry *entry, *tmp; > + LIST_HEAD(temp_ima_keys); > + > + if (ima_process_keys) > + return; > > thanks, > -lakshmi