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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id EB380C4167B for ; Tue, 28 Nov 2023 00:09:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233936AbjK1AJS (ORCPT ); Mon, 27 Nov 2023 19:09:18 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52734 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229821AbjK1AJQ (ORCPT ); Mon, 27 Nov 2023 19:09:16 -0500 Received: from mx1.sberdevices.ru (mx1.sberdevices.ru [37.18.73.165]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 23B68137 for ; Mon, 27 Nov 2023 16:09:21 -0800 (PST) Received: from p-infra-ksmg-sc-msk01 (localhost [127.0.0.1]) by mx1.sberdevices.ru (Postfix) with ESMTP id AD7BE100017; Tue, 28 Nov 2023 03:09:19 +0300 (MSK) DKIM-Filter: OpenDKIM Filter v2.11.0 mx1.sberdevices.ru AD7BE100017 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=salutedevices.com; s=mail; t=1701130159; bh=RspzObIsUHICsIUxC0hsMmw1kijkxCac0RSZzLLuBi8=; h=From:To:Subject:Date:Message-ID:MIME-Version:Content-Type:From; b=vcv6HPoQN2WVZ+a3/EPmBjoXtkDeIOhhHZi1eiD1uPPIlc+qy2v8YkG9QDPhPkJn9 nKcVdHObuAKuvmMMzs3gqYNmlpezkihpPfasMmO9jKh1uoOjwmQIFml4YIx0cHdaWe VkbvirCtQduEc6RJ23Loq3IfL48oOEKsVtC8KD5SF9Qct5QKv1aMOKcWMogpV+Yt4d +/DD+RNZJSmg7VQcs20RcUCaeu/UjA55JixEIYAeWeJNUAR3KrsB2aWlQcU3EL4ED/ Q5HmQbHJqeElNn2aTEyvwe/Yr/cxYsE5D20b93/RdPCr+gVZgcYcC3CL2cCfl0IXLx MwzhoL96SHAaw== Received: from p-i-exch-sc-m01.sberdevices.ru (p-i-exch-sc-m01.sberdevices.ru [172.16.192.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mx1.sberdevices.ru (Postfix) with ESMTPS; Tue, 28 Nov 2023 03:09:18 +0300 (MSK) Received: from localhost.localdomain (100.64.160.123) by p-i-exch-sc-m01.sberdevices.ru (172.16.192.107) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1118.40; Tue, 28 Nov 2023 03:09:18 +0300 From: George Stark To: , , , , , , , CC: , Subject: [RFC PATCH 1/1] locking: introduce devm_mutex_init and devm_mutex_destroy Date: Tue, 28 Nov 2023 03:09:10 +0300 Message-ID: <20231128000910.73784-1-gnstark@salutedevices.com> X-Mailer: git-send-email 2.42.0 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain X-Originating-IP: [100.64.160.123] X-ClientProxiedBy: p-i-exch-sc-m01.sberdevices.ru (172.16.192.107) To p-i-exch-sc-m01.sberdevices.ru (172.16.192.107) X-KSMG-Rule-ID: 10 X-KSMG-Message-Action: clean X-KSMG-AntiSpam-Lua-Profiles: 181630 [Nov 27 2023] X-KSMG-AntiSpam-Version: 6.0.0.2 X-KSMG-AntiSpam-Envelope-From: gnstark@salutedevices.com X-KSMG-AntiSpam-Rate: 0 X-KSMG-AntiSpam-Status: not_detected X-KSMG-AntiSpam-Method: none X-KSMG-AntiSpam-Auth: dkim=none X-KSMG-AntiSpam-Info: LuaCore: 5 0.3.5 98d108ddd984cca1d7e65e595eac546a62b0144b, {Tracking_from_domain_doesnt_match_to}, p-i-exch-sc-m01.sberdevices.ru:5.0.1,7.1.1;100.64.160.123:7.1.2;d41d8cd98f00b204e9800998ecf8427e.com:7.1.1;127.0.0.199:7.1.2;salutedevices.com:7.1.1, FromAlignment: s, ApMailHostAddress: 100.64.160.123 X-MS-Exchange-Organization-SCL: -1 X-KSMG-AntiSpam-Interceptor-Info: scan successful X-KSMG-AntiPhishing: Clean X-KSMG-LinksScanning: Clean X-KSMG-AntiVirus: Kaspersky Secure Mail Gateway, version 2.0.1.6960, bases: 2023/11/27 21:09:00 #22555279 X-KSMG-AntiVirus-Status: Clean, skipped Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Using of devm API leads to certain order of releasing resources. So all dependent resources which are not devm-wrapped should be deleted with respect to devm-release order. Mutex is one of such objects that often is bound to other resources and has no own devm wrapping. Since mutex_destroy() actually does nothing in non-debug builds frequently calling mutex_destroy() is just ignored which is safe for now but wrong formally and can lead to a problem if mutex_destroy() will be extended so introduce devm_mutex_init() and devm_mutex_destroy(). Signed-off-by: George Stark --- include/linux/mutex.h | 3 +++ kernel/locking/mutex.c | 37 +++++++++++++++++++++++++++++++++++++ 2 files changed, 40 insertions(+) diff --git a/include/linux/mutex.h b/include/linux/mutex.h index a33aa9eb9fc3..7f60cd842322 100644 --- a/include/linux/mutex.h +++ b/include/linux/mutex.h @@ -119,6 +119,9 @@ do { \ extern void __mutex_init(struct mutex *lock, const char *name, struct lock_class_key *key); +int devm_mutex_init(struct device *dev, struct mutex *lock); +void devm_mutex_destroy(struct device *dev, struct mutex *lock); + /** * mutex_is_locked - is the mutex locked * @lock: the mutex to be queried diff --git a/kernel/locking/mutex.c b/kernel/locking/mutex.c index d973fe6041bf..a73124719dcb 100644 --- a/kernel/locking/mutex.c +++ b/kernel/locking/mutex.c @@ -56,6 +56,43 @@ __mutex_init(struct mutex *lock, const char *name, struct lock_class_key *key) } EXPORT_SYMBOL(__mutex_init); +static void devm_mutex_release(struct device *dev, void *res) +{ + mutex_destroy(*(struct mutex **)res); +} + +static int devm_mutex_match(struct device *dev, void *res, void *data) +{ + struct mutex **r = res; + + if (WARN_ON(!r || !*r)) + return 0; + + return *r == data; +} + +int devm_mutex_init(struct device *dev, struct mutex *lock) +{ + struct mutex **ptr; + + ptr = devres_alloc(devm_mutex_release, sizeof(*ptr), GFP_KERNEL); + if (!ptr) + return -ENOMEM; + + mutex_init(lock); + + *ptr = lock; + devres_add(dev, ptr); + return 0; +} +EXPORT_SYMBOL(devm_mutex_init); + +void devm_mutex_destroy(struct device *dev, struct mutex *lock) +{ + devres_release(dev, devm_mutex_release, devm_mutex_match, lock); +} +EXPORT_SYMBOL(devm_mutex_destroy); + /* * @owner: contains: 'struct task_struct *' to the current lock owner, * NULL means not owned. Since task_struct pointers are aligned at -- 2.38.4