From patchwork Mon Nov 9 15:04:15 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Zhang Qilong X-Patchwork-Id: 323420 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=-12.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham 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 81A6FC61DD8 for ; Mon, 9 Nov 2020 15:00:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 422F72083B for ; Mon, 9 Nov 2020 15:00:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729905AbgKIPAp (ORCPT ); Mon, 9 Nov 2020 10:00:45 -0500 Received: from szxga05-in.huawei.com ([45.249.212.191]:7506 "EHLO szxga05-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729940AbgKIPAp (ORCPT ); Mon, 9 Nov 2020 10:00:45 -0500 Received: from DGGEMS402-HUB.china.huawei.com (unknown [172.30.72.59]) by szxga05-in.huawei.com (SkyGuard) with ESMTP id 4CVDgr5GkxzhfKR; Mon, 9 Nov 2020 23:00:24 +0800 (CST) Received: from huawei.com (10.175.127.227) by DGGEMS402-HUB.china.huawei.com (10.3.19.202) with Microsoft SMTP Server id 14.3.487.0; Mon, 9 Nov 2020 23:00:27 +0800 From: Zhang Qilong To: , , , CC: , Subject: [PATCH v2 1/2] PM: runtime: Add a general runtime get sync operation to deal with usage counter Date: Mon, 9 Nov 2020 23:04:15 +0800 Message-ID: <20201109150416.1877878-2-zhangqilong3@huawei.com> X-Mailer: git-send-email 2.25.4 In-Reply-To: <20201109150416.1877878-1-zhangqilong3@huawei.com> References: <20201109150416.1877878-1-zhangqilong3@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.175.127.227] X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org In many case, we need to check return value of pm_runtime_get_sync, but it brings a trouble to the usage counter processing. Many callers forget to decrease the usage counter when it failed. It has been discussed a lot[0][1]. So we add a function to deal with the usage counter for better coding. [0]https://lkml.org/lkml/2020/6/14/88 [1]https://patchwork.ozlabs.org/project/linux-tegra/patch/20200520095148.10995-1-dinghao.liu@zju.edu.cn/ Signed-off-by: Zhang Qilong --- include/linux/pm_runtime.h | 30 ++++++++++++++++++++++++++++++ 1 file changed, 30 insertions(+) diff --git a/include/linux/pm_runtime.h b/include/linux/pm_runtime.h index 4b708f4e8eed..6549ce764400 100644 --- a/include/linux/pm_runtime.h +++ b/include/linux/pm_runtime.h @@ -386,6 +386,36 @@ static inline int pm_runtime_get_sync(struct device *dev) return __pm_runtime_resume(dev, RPM_GET_PUT); } +/** + * pm_runtime_general_get - Bump up usage counter of a device and resume it. + * @dev: Target device. + * + * Increase runtime PM usage counter of @dev first, and carry out runtime-resume + * of it synchronously. If __pm_runtime_resume return negative value(device is in + * error state), we to need decrease the usage counter before it return. If + * __pm_runtime_resume return positive value, it means the runtime of device has + * already been in active state, and we let the new wrapper return zero instead. + * + * The possible return values of this function is zero or negative value. + * zero: + * - it means resume succeeed or runtime of device has already been active, the + * runtime PM usage counter of @dev remains incremented. + * negative: + * - it means failure and the runtime PM usage counter of @dev has been balanced. + */ +static inline int pm_runtime_general_get(struct device *dev) +{ + int ret = 0; + + ret = __pm_runtime_resume(dev, RPM_GET_PUT); + if (ret < 0) { + pm_runtime_put_noidle(dev); + return ret; + } + + return 0; +} + /** * pm_runtime_put - Drop device usage counter and queue up "idle check" if 0. * @dev: Target device. From patchwork Mon Nov 9 15:04:16 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Zhang Qilong X-Patchwork-Id: 323421 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=-12.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED, USER_AGENT_GIT autolearn=unavailable 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 2E3E6C2D0A3 for ; Mon, 9 Nov 2020 15:00:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D261920853 for ; Mon, 9 Nov 2020 15:00:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730449AbgKIPAg (ORCPT ); Mon, 9 Nov 2020 10:00:36 -0500 Received: from szxga05-in.huawei.com ([45.249.212.191]:7505 "EHLO szxga05-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729899AbgKIPAf (ORCPT ); Mon, 9 Nov 2020 10:00:35 -0500 Received: from DGGEMS402-HUB.china.huawei.com (unknown [172.30.72.59]) by szxga05-in.huawei.com (SkyGuard) with ESMTP id 4CVDgr53Fkzhf9l; Mon, 9 Nov 2020 23:00:24 +0800 (CST) Received: from huawei.com (10.175.127.227) by DGGEMS402-HUB.china.huawei.com (10.3.19.202) with Microsoft SMTP Server id 14.3.487.0; Mon, 9 Nov 2020 23:00:28 +0800 From: Zhang Qilong To: , , , CC: , Subject: [PATCH v2 2/2] net: fec: Fix reference count leak in fec series ops Date: Mon, 9 Nov 2020 23:04:16 +0800 Message-ID: <20201109150416.1877878-3-zhangqilong3@huawei.com> X-Mailer: git-send-email 2.25.4 In-Reply-To: <20201109150416.1877878-1-zhangqilong3@huawei.com> References: <20201109150416.1877878-1-zhangqilong3@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.175.127.227] X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org pm_runtime_get_sync() will increment pm usage at first and it will resume the device later. If runtime of the device has error or device is in inaccessible state(or other error state), resume operation will fail. If we do not call put operation to decrease the reference, it will result in reference count leak. Moreover, this device cannot enter the idle state and always stay busy or other non-idle state later. So we fixed it by replacing it with pm_runtime_general_get. Fixes: 8fff755e9f8d0 ("net: fec: Ensure clocks are enabled while using mdio bus") Signed-off-by: Zhang Qilong --- drivers/net/ethernet/freescale/fec_main.c | 12 +++++------- 1 file changed, 5 insertions(+), 7 deletions(-) diff --git a/drivers/net/ethernet/freescale/fec_main.c b/drivers/net/ethernet/freescale/fec_main.c index d7919555250d..695720f8263f 100644 --- a/drivers/net/ethernet/freescale/fec_main.c +++ b/drivers/net/ethernet/freescale/fec_main.c @@ -1808,7 +1808,7 @@ static int fec_enet_mdio_read(struct mii_bus *bus, int mii_id, int regnum) int ret = 0, frame_start, frame_addr, frame_op; bool is_c45 = !!(regnum & MII_ADDR_C45); - ret = pm_runtime_get_sync(dev); + ret = pm_runtime_general_get(dev); if (ret < 0) return ret; @@ -1867,11 +1867,9 @@ static int fec_enet_mdio_write(struct mii_bus *bus, int mii_id, int regnum, int ret, frame_start, frame_addr; bool is_c45 = !!(regnum & MII_ADDR_C45); - ret = pm_runtime_get_sync(dev); + ret = pm_runtime_general_get(dev); if (ret < 0) return ret; - else - ret = 0; if (is_c45) { frame_start = FEC_MMFR_ST_C45; @@ -2275,7 +2273,7 @@ static void fec_enet_get_regs(struct net_device *ndev, u32 i, off; int ret; - ret = pm_runtime_get_sync(dev); + ret = pm_runtime_general_get(dev); if (ret < 0) return; @@ -2976,7 +2974,7 @@ fec_enet_open(struct net_device *ndev) int ret; bool reset_again; - ret = pm_runtime_get_sync(&fep->pdev->dev); + ret = pm_runtime_general_get(&fep->pdev->dev); if (ret < 0) return ret; @@ -3770,7 +3768,7 @@ fec_drv_remove(struct platform_device *pdev) struct device_node *np = pdev->dev.of_node; int ret; - ret = pm_runtime_get_sync(&pdev->dev); + ret = pm_runtime_general_get(&pdev->dev); if (ret < 0) return ret;