From patchwork Tue Oct 14 12:35:11 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Krzysztof Kozlowski X-Patchwork-Id: 5080151 Return-Path: X-Original-To: patchwork-linux-arm@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork1.web.kernel.org (Postfix) with ESMTP id 9664F9F295 for ; Tue, 14 Oct 2014 12:40:50 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 6E9BD20127 for ; Tue, 14 Oct 2014 12:40:49 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.9]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id CA80D20179 for ; Tue, 14 Oct 2014 12:40:47 +0000 (UTC) Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1Xe1M0-0005Cy-Um; Tue, 14 Oct 2014 12:37:28 +0000 Received: from mailout1.w1.samsung.com ([210.118.77.11]) by bombadil.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1Xe1Lk-00052N-Rp for linux-arm-kernel@lists.infradead.org; Tue, 14 Oct 2014 12:37:14 +0000 Received: from eucpsbgm1.samsung.com (unknown [203.254.199.244]) by mailout1.w1.samsung.com (Oracle Communications Messaging Server 7u4-24.01(7.0.4.24.0) 64bit (built Nov 17 2011)) with ESMTP id <0NDF005IMPU8ELC0@mailout1.w1.samsung.com> for linux-arm-kernel@lists.infradead.org; Tue, 14 Oct 2014 13:39:44 +0100 (BST) X-AuditID: cbfec7f4-b7f156d0000063c7-97-543d18e29d43 Received: from eusync2.samsung.com ( [203.254.199.212]) by eucpsbgm1.samsung.com (EUCPMTA) with SMTP id 73.7C.25543.2E81D345; Tue, 14 Oct 2014 13:36:50 +0100 (BST) Received: from AMDC1943.digital.local ([106.116.151.171]) by eusync2.samsung.com (Oracle Communications Messaging Server 7u4-23.01(7.0.4.23.0) 64bit (built Aug 10 2011)) with ESMTPA id <0NDF005XWPP45P40@eusync2.samsung.com>; Tue, 14 Oct 2014 13:36:49 +0100 (BST) From: Krzysztof Kozlowski To: Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" , x86@kernel.org, Linus Walleij , Samuel Ortiz , Lee Jones , Sebastian Reichel , Dmitry Eremin-Solenikov , David Woodhouse , Krzysztof Kozlowski , Konrad Rzeszutek Wilk , "Rafael J. Wysocki" , Lv Zheng , Bjorn Helgaas , linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-pm@vger.kernel.org Subject: [PATCH 1/7] power_supply: Add power_supply_put for decrementing device reference counter Date: Tue, 14 Oct 2014 14:35:11 +0200 Message-id: <1413290117-13082-2-git-send-email-k.kozlowski@samsung.com> X-Mailer: git-send-email 1.9.1 In-reply-to: <1413290117-13082-1-git-send-email-k.kozlowski@samsung.com> References: <1413290117-13082-1-git-send-email-k.kozlowski@samsung.com> X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFvrMLMWRmVeSWpSXmKPExsVy+t/xK7qPJGxDDFZPYbE4uFXTYuOM9awW S5oyLCY9ec9sMXHlZGaLaRvFLV6/MLRYtvgpo8XZpjfsFve/HmW0mPJnOZPFpsfXWC0u75rD ZvG59wijxcelG1gt1h65y25x6cACJou7p46yWTxe8Zbd4nQ3q8Xp3SUWmzdNZbb4seExq4O4 x4T+T4weO2fdZfdYsKnUY/MKLY/Fe14yeWxa1cnmcefaHjaPd+fOsXvMOxnosXlJvcfHp7dY PN7vu8rm0bdlFaPHitXf2T0+b5LzONHyhTVAIIrLJiU1J7MstUjfLoErY/rtRpaCD7IVf25+ Y21gbJbsYuTkkBAwkbi5cR0LhC0mceHeerYuRi4OIYGljBK3Dy+AcvqYJA70djKCVLEJGEts Xr4ELCEisIlVYtuKBUwgDrPAdUaJ1Vdvs4NUCQskSzxavpIJxGYRUJX41X2LFcTmFXCXWNqx A2qfnMTJY5OB4hwcnAIeEhN3qYGYQkAls57JTmDkXcDIsIpRNLU0uaA4KT3XUK84Mbe4NC9d Lzk/dxMjJKK+7GBcfMzqEKMAB6MSD29BpE2IEGtiWXFl7iFGCQ5mJRFeBQ7bECHelMTKqtSi /Pii0pzU4kOMTBycUg2MPa0ttx751ThMZVvIJVX5l8VmHqNuem8qT8l23Z2KO9zusTZlvecJ 2v13t+KMAMWmvYZaOufn3tcTE76r8efJ+xXPfYvv1J98JiHsb1Vb+GXd3ad7X8YZ2JRxvDk3 a/8u1r7ynPjOviaGpy2Tp/YlahoprLl+ce/Fjekn3lqEa+TsLWBKabmhxFKckWioxVxUnAgA 7cDoaIYCAAA= X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20141014_053713_098548_730CD9C0 X-CRM114-Status: GOOD ( 12.28 ) X-Spam-Score: -5.0 (-----) Cc: Bartlomiej Zolnierkiewicz , Kyungmin Park , Anton Vorontsov , Pavel Machek , Marek Szyprowski X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.18-1 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Spam-Status: No, score=-1.9 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_NONE, T_RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP The power_supply_get_by_phandle() and power_supply_get_by_name() use function class_find_device() for obtaining the reference to power supply. Each use of class_find_device() increases the power supply's device reference counter. However the reference counter was not decreased by users of this API. Thus final device_unregister() call from power_supply_unregister() could not release the device and clean up its resources. This lead to memory leak if one pf power_supply_get_*() was called between registering and unregistering the power supply. Add and document new API power_supply_put() for decrementing the reference counter. Signed-off-by: Krzysztof Kozlowski --- drivers/power/power_supply_core.c | 41 +++++++++++++++++++++++++++++++++++++++ include/linux/power_supply.h | 1 + 2 files changed, 42 insertions(+) diff --git a/drivers/power/power_supply_core.c b/drivers/power/power_supply_core.c index 8e36986a73e1..ca2b6442e0b3 100644 --- a/drivers/power/power_supply_core.c +++ b/drivers/power/power_supply_core.c @@ -331,6 +331,17 @@ static int power_supply_match_device_by_name(struct device *dev, const void *dat return strcmp(psy->name, name) == 0; } +/** + * power_supply_get_by_name() - Search for a power supply and returns its ref + * @name: Power supply name to fetch + * + * If power supply was found, it increases reference count for the + * internal power supply's device. The user should power_supply_put() + * after usage. + * + * Return: On success returns a reference to a power supply with + * matching name equals to @name, a NULL otherwise. + */ struct power_supply *power_supply_get_by_name(const char *name) { struct device *dev = class_find_device(power_supply_class, NULL, name, @@ -340,12 +351,42 @@ struct power_supply *power_supply_get_by_name(const char *name) } EXPORT_SYMBOL_GPL(power_supply_get_by_name); +/** + * power_supply_put() - Drop reference obtained with power_supply_get_by_name + * @psy: Reference to put + * + * The reference to power supply should be put before unregistering + * the power supply. + */ +void power_supply_put(struct power_supply *psy) +{ + might_sleep(); + + if (!psy) + return; + + put_device(psy->dev); +} +EXPORT_SYMBOL_GPL(power_supply_put); + #ifdef CONFIG_OF static int power_supply_match_device_node(struct device *dev, const void *data) { return dev->parent && dev->parent->of_node == data; } +/** + * power_supply_get_by_phandle() - Search for a power supply and returns its ref + * @np: Pointer to device node holding phandle property + * @phandle_name: Name of property holding a power supply name + * + * If power supply was found, it increases reference count for the + * internal power supply's device. The user should power_supply_put() + * after usage. + * + * Return: On success returns a reference to a power supply with + * matching name equals to value under @property, NULL or ERR_PTR otherwise. + */ struct power_supply *power_supply_get_by_phandle(struct device_node *np, const char *property) { diff --git a/include/linux/power_supply.h b/include/linux/power_supply.h index 44e749c65505..1b6db883e090 100644 --- a/include/linux/power_supply.h +++ b/include/linux/power_supply.h @@ -256,6 +256,7 @@ extern struct atomic_notifier_head power_supply_notifier; extern int power_supply_reg_notifier(struct notifier_block *nb); extern void power_supply_unreg_notifier(struct notifier_block *nb); extern struct power_supply *power_supply_get_by_name(const char *name); +extern void power_supply_put(struct power_supply *psy); #ifdef CONFIG_OF extern struct power_supply *power_supply_get_by_phandle(struct device_node *np, const char *property);