From patchwork Tue Nov 4 15:10:30 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Krzysztof Kozlowski X-Patchwork-Id: 5228681 Return-Path: X-Original-To: patchwork-linux-arm@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork2.web.kernel.org (Postfix) with ESMTP id 3E202C11AC for ; Tue, 4 Nov 2014 15:14:01 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 41D7E20166 for ; Tue, 4 Nov 2014 15:14:00 +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 5998B2012B for ; Tue, 4 Nov 2014 15:13:59 +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 1XlflQ-0006cz-Fu; Tue, 04 Nov 2014 15:11:20 +0000 Received: from mailout2.w1.samsung.com ([210.118.77.12]) by bombadil.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1XlflF-0006SG-2z for linux-arm-kernel@lists.infradead.org; Tue, 04 Nov 2014 15:11:09 +0000 Received: from eucpsbgm1.samsung.com (unknown [203.254.199.244]) by mailout2.w1.samsung.com (Oracle Communications Messaging Server 7u4-24.01(7.0.4.24.0) 64bit (built Nov 17 2011)) with ESMTP id <0NEI00F8TSYMS720@mailout2.w1.samsung.com> for linux-arm-kernel@lists.infradead.org; Tue, 04 Nov 2014 15:13:34 +0000 (GMT) X-AuditID: cbfec7f4-b7f6c6d00000120b-8d-5458ec761ffb Received: from eusync1.samsung.com ( [203.254.199.211]) by eucpsbgm1.samsung.com (EUCPMTA) with SMTP id 0E.E6.04619.67CE8545; Tue, 04 Nov 2014 15:10:46 +0000 (GMT) Received: from AMDC1943.digital.local ([106.116.151.171]) by eusync1.samsung.com (Oracle Communications Messaging Server 7u4-23.01(7.0.4.23.0) 64bit (built Aug 10 2011)) with ESMTPA id <0NEI00A4OSTTFF40@eusync1.samsung.com>; Tue, 04 Nov 2014 15:10:46 +0000 (GMT) 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 , 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 RESEND v2 1/7] power_supply: Add power_supply_put for decrementing device reference counter Date: Tue, 04 Nov 2014 16:10:30 +0100 Message-id: <1415113836-26098-2-git-send-email-k.kozlowski@samsung.com> X-Mailer: git-send-email 1.9.1 In-reply-to: <1415113836-26098-1-git-send-email-k.kozlowski@samsung.com> References: <1415113836-26098-1-git-send-email-k.kozlowski@samsung.com> X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFvrKLMWRmVeSWpSXmKPExsVy+t/xy7plbyJCDGZMkLM4uFXTYuOM9awW S5oyLCY9ec9sMXHlZGaLaRvFLV6/MLRYtvgpo8XZpjfsFve/HmW0mPJnOZPFpsfXWC0u75rD ZvG59wijxcelG1gt1h65y25x6cACJou7p46yWTxe8Zbd4nQ3q8Xp3SUWmzdNZbb4seExq4O4 x4T+T4weO2fdZfdYsKnUY/MKLY/Fe14yeWxa1cnmcefaHjaPd+fOsXvMOxnosXlJvcfHp7dY PN7vu8rm0bdlFaPHitXf2T0+b5LzONHyhTVAIIrLJiU1J7MstUjfLoEr49njO+wFLXIVC/9u YGtgnC3ZxcjJISFgItF46SorhC0mceHeerYuRi4OIYGljBJP3z9ggXD6mCSeTp3GCFLFJmAs sXn5ErAqEYFGVolzW98wgTjMAh1MErdbdoLNEhbIlWiYto4JxGYRUJU4/uwzG4jNK+AucXv9 PEaIfXISJ49NBqvnFPCQ2Nnynx3EFgKqebNxO+sERt4FjAyrGEVTS5MLipPScw31ihNzi0vz 0vWS83M3MUKi6ssOxsXHrA4xCnAwKvHwZqhHhAixJpYVV+YeYpTgYFYS4VV/DBTiTUmsrEot yo8vKs1JLT7EyMTBKdXAGPX4U6Nje6/D6Vc/S7jK5j+67MLyyOVV60n51vy0k3dfMnVItPXv Mp9zYMmZC9lpN86WPjn/4LjWT7EGy30/FC/LqdU+XlAlo3rhUXjAt5OF+z4lSq6zzfj+LnKB 6zLFPr57n/dsKTRL3/c0POGsLNu8+x22aRFtOxYvXpp1aU7Y1ozLyrqPPimxFGckGmoxFxUn AgCplyWBiAIAAA== X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20141104_071109_385804_04F6F923 X-CRM114-Status: GOOD ( 11.81 ) X-Spam-Score: -5.6 (-----) Cc: Krzysztof Kozlowski , Bartlomiej Zolnierkiewicz , Anton Vorontsov , Kyungmin Park , 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=-2.5 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_NONE, 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 at least once power_supply_get_by_*() 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 Acked-by: Pavel Machek --- drivers/power/power_supply_core.c | 38 ++++++++++++++++++++++++++++++++++++++ include/linux/power_supply.h | 1 + 2 files changed, 39 insertions(+) diff --git a/drivers/power/power_supply_core.c b/drivers/power/power_supply_core.c index bd8f5be0d976..cf860d2fd8c9 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 +351,39 @@ 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(); + + 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 0ef515301aaf..9abb2aef55eb 100644 --- a/include/linux/power_supply.h +++ b/include/linux/power_supply.h @@ -262,6 +262,7 @@ 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);