From patchwork Thu Mar 12 07:44:12 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Krzysztof Kozlowski X-Patchwork-Id: 5991401 Return-Path: X-Original-To: patchwork-linux-input@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork1.web.kernel.org (Postfix) with ESMTP id 640459F2A9 for ; Thu, 12 Mar 2015 07:46:16 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 7BB9D2034B for ; Thu, 12 Mar 2015 07:46:15 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8579820383 for ; Thu, 12 Mar 2015 07:46:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753230AbbCLHp7 (ORCPT ); Thu, 12 Mar 2015 03:45:59 -0400 Received: from mailout2.w1.samsung.com ([210.118.77.12]:64795 "EHLO mailout2.w1.samsung.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753305AbbCLHpN (ORCPT ); Thu, 12 Mar 2015 03:45:13 -0400 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 <0NL300EF29PPCU50@mailout2.w1.samsung.com>; Thu, 12 Mar 2015 07:49:01 +0000 (GMT) X-AuditID: cbfec7f4-b7f126d000001e9a-84-5501436bb963 Received: from eusync2.samsung.com ( [203.254.199.212]) by eucpsbgm1.samsung.com (EUCPMTA) with SMTP id C8.FA.07834.B6341055; Thu, 12 Mar 2015 07:42:35 +0000 (GMT) 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 <0NL300KWS9IOZC60@eusync2.samsung.com>; Thu, 12 Mar 2015 07:45:01 +0000 (GMT) From: Krzysztof Kozlowski To: Jiri Kosina , Henrik Rydberg , linux-input@vger.kernel.org, linux-kernel@vger.kernel.org, Sebastian Reichel , Dmitry Eremin-Solenikov , David Woodhouse , linux-pm@vger.kernel.org Cc: Krzysztof Kozlowski Subject: [RESEND PATCH v6 14/22] power_supply: Add power_supply_put for decrementing device reference counter Date: Thu, 12 Mar 2015 08:44:12 +0100 Message-id: <1426146260-30081-15-git-send-email-k.kozlowski@samsung.com> X-Mailer: git-send-email 1.9.1 In-reply-to: <1426146260-30081-1-git-send-email-k.kozlowski@samsung.com> References: <1426146260-30081-1-git-send-email-k.kozlowski@samsung.com> X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFmpnluLIzCtJLcpLzFFi42I5/e/4Fd1sZ8ZQg3lzrCwmPXnPbDFx5WRm i91zFrNYvH5haHHz0zdWi8u75rBZfO49wmhx4ts0JovTu0scOD0+r3rF6rFz1l12j80rtDw2 repk8+jbsorR48yCI+wenzfJBbBHcdmkpOZklqUW6dslcGVMXL+SveC/XMWbpXvZGxh7pLoY OTkkBEwkvnxrYYKwxSQu3FvP1sXIxSEksJRR4sXWOVBOH5PEtmt9jCBVbALGEpuXLwFLiAjM Z5LoX3WCFSTBLGAo8fPdH3YQW1ggX+LkiuUsIDaLgKpE3/8mZhCbV8BD4tGTv6wQ6+QkTh6b DGRzcHACxV8v4gEJCwm4S8xc9ol9AiPvAkaGVYyiqaXJBcVJ6bmGesWJucWleel6yfm5mxgh gfdlB+PiY1aHGAU4GJV4eCP6GEKFWBPLiitzDzFKcDArifByWDGGCvGmJFZWpRblxxeV5qQW H2Jk4uCUamBUNI10zYn/K8kSO2m+Ol/gn2sfV785v9z05jSX1hWdnVf/lnVmme6XP5XY8pHh 7Ze0+ztt6jyrrOvW+PxNrPk7u6w3qWWmwM+7Se3PXVuvc7TM/LWHd2P8991MT58lXK2oLddK 2+ovxr3H6uu5Nx0Km0LW/zaI6/tW8ZOBb//KUMW2bL7SK3OVWIozEg21mIuKEwGdBf5WGgIA AA== Sender: linux-input-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-input@vger.kernel.org X-Spam-Status: No, score=-6.9 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, 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 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 Reviewed-by: Bartlomiej Zolnierkiewicz Reviewed-by: Sebastian Reichel --- 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 e51405b176c8..b4ec14683b7f 100644 --- a/drivers/power/power_supply_core.c +++ b/drivers/power/power_supply_core.c @@ -336,6 +336,17 @@ static int power_supply_match_device_by_name(struct device *dev, const void *dat return strcmp(psy->desc->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, @@ -345,12 +356,39 @@ 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 ea15eb68f609..75a1dd8dc56e 100644 --- a/include/linux/power_supply.h +++ b/include/linux/power_supply.h @@ -282,6 +282,7 @@ 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);