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 A280FC43603 for ; Mon, 16 Dec 2019 12:30:28 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 77E5F20726 for ; Mon, 16 Dec 2019 12:30:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727837AbfLPMa1 (ORCPT ); Mon, 16 Dec 2019 07:30:27 -0500 Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:51198 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727542AbfLPMaY (ORCPT ); Mon, 16 Dec 2019 07:30:24 -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 xBGCR02Q015505 for ; Mon, 16 Dec 2019 07:30:22 -0500 Received: from e06smtp04.uk.ibm.com (e06smtp04.uk.ibm.com [195.75.94.100]) by mx0a-001b2d01.pphosted.com with ESMTP id 2wwe361g66-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Mon, 16 Dec 2019 07:30:21 -0500 Received: from localhost by e06smtp04.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) Mon, 16 Dec 2019 12:30:15 -0000 Received: from d06av21.portsmouth.uk.ibm.com (d06av21.portsmouth.uk.ibm.com [9.149.105.232]) by b06avi18878370.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id xBGCUEVb43450644 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Mon, 16 Dec 2019 12:30:14 GMT Received: from d06av21.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id A670B5204E; Mon, 16 Dec 2019 12:30:14 +0000 (GMT) Received: from localhost.localdomain (unknown [9.85.187.190]) by d06av21.portsmouth.uk.ibm.com (Postfix) with ESMTP id 869FE52057; Mon, 16 Dec 2019 12:30:13 +0000 (GMT) Subject: Re: [PATCH v4 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 In-Reply-To: <20191213171827.28657-2-nramas@linux.microsoft.com> References: <20191213171827.28657-1-nramas@linux.microsoft.com> <20191213171827.28657-2-nramas@linux.microsoft.com> Content-Type: text/plain; charset="UTF-8" Date: Mon, 16 Dec 2019 07:30:00 -0500 Mime-Version: 1.0 X-Mailer: Evolution 3.20.5 (3.20.5-1.fc24) Content-Transfer-Encoding: 8bit X-TM-AS-GCONF: 00 x-cbid: 19121612-0016-0000-0000-000002D55DE2 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 19121612-0017-0000-0000-000033379141 Message-Id: <1576499400.4579.305.camel@linux.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.95,18.0.572 definitions=2019-12-16_04:2019-12-16,2019-12-16 signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 bulkscore=0 adultscore=0 lowpriorityscore=0 phishscore=0 spamscore=0 impostorscore=0 clxscore=1015 mlxlogscore=999 malwarescore=0 mlxscore=0 suspectscore=2 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-1910280000 definitions=main-1912160112 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 2019-12-13 at 09:18 -0800, Lakshmi Ramasubramanian 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); > + bool process = false; > + > + 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); > + > + if (!ima_process_keys) { > + ima_process_keys = true; Thank you for moving the initialization here.  The comment is now valid and the following code is now guaranteed to execute just once. > + > + if (!list_empty(&ima_keys)) { > + list_for_each_entry_safe(entry, tmp, &ima_keys, list) > + list_move_tail(&entry->list, &temp_ima_keys); > + process = true; > + } > + } > + > + mutex_unlock(&ima_keys_mutex); > + > + if (!process) > + return; The new changes - checking if the list is empty and this test - are unnecessary, as you implied earlier. Mimi > + > + list_for_each_entry_safe(entry, tmp, &temp_ima_keys, list) { > + process_buffer_measurement(entry->payload, entry->payload_len, > + entry->keyring_name, KEY_CHECK, 0, > + entry->keyring_name); > + list_del(&entry->list); > + ima_free_key_entry(entry); > + } > +} > + > /** > * ima_post_key_create_or_update - measure asymmetric keys > * @keyring: keyring to which the key is linked to