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=-9.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,USER_AGENT_SANE_1,USER_IN_DEF_DKIM_WL 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 244A9C2D0C9 for ; Fri, 13 Dec 2019 01:59:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id DDBD52253D for ; Fri, 13 Dec 2019 01:59:16 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=linux.microsoft.com header.i=@linux.microsoft.com header.b="CNuTiTMq" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731903AbfLMB7Q (ORCPT ); Thu, 12 Dec 2019 20:59:16 -0500 Received: from linux.microsoft.com ([13.77.154.182]:48632 "EHLO linux.microsoft.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727778AbfLMB7Q (ORCPT ); Thu, 12 Dec 2019 20:59:16 -0500 Received: from [10.137.112.108] (unknown [131.107.174.108]) by linux.microsoft.com (Postfix) with ESMTPSA id 61D2F20B7187; Thu, 12 Dec 2019 17:59:15 -0800 (PST) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com 61D2F20B7187 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1576202355; bh=YxXTmKallgLBW7/eDWy6Lx19SJtawJZqEYTFJolyfhY=; h=Subject:To:Cc:References:From:Date:In-Reply-To:From; b=CNuTiTMqkeQ2MswdQVXysPfvcdmZ2cNrJnYYqac+2rU02Wh60moR8u+XAW6oERWIe v2fUa6G0XMEN6ITGO38tGW8Vl6yhrvEshMCKRT4PYPb6zoMhiQ3eEZbGWXgU6IIiQk dXAYW0MEXYLtWnF6XiHmz0Dw4ImpveaIdcZU597w= Subject: Re: [PATCH v3 1/2] IMA: Define workqueue for early boot "key" measurements To: Mimi Zohar , 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 References: <20191213004250.21132-1-nramas@linux.microsoft.com> <20191213004250.21132-2-nramas@linux.microsoft.com> <1576202134.4579.189.camel@linux.ibm.com> From: Lakshmi Ramasubramanian Message-ID: <6e0dad33-66f9-4807-d08d-ff30396cec5e@linux.microsoft.com> Date: Thu, 12 Dec 2019 17:59:11 -0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.2.2 MIME-Version: 1.0 In-Reply-To: <1576202134.4579.189.camel@linux.ibm.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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(). +void ima_process_queued_keys(void) +{ + struct ima_key_entry *entry, *tmp; + LIST_HEAD(temp_ima_keys); + + if (ima_process_keys) + return; thanks, -lakshmi