From 76f05d88623e559eb9fc41db9fb911e67fab0e7a Mon Sep 17 00:00:00 2001 From: M Chetan Kumar Date: Mon, 14 Feb 2022 12:46:52 +0530 Subject: net: wwan: debugfs obtained dev reference not dropped WWAN driver call's wwan_get_debugfs_dir() to obtain WWAN debugfs dir entry. As part of this procedure it returns a reference to a found device. Since there is no debugfs interface available at WWAN subsystem, it is not possible to drop dev reference post debugfs use. This leads to side effects like post wwan driver load and reload the wwan instance gets increment from wwanX to wwanX+1. A new debugfs interface is added in wwan subsystem so that wwan driver can drop the obtained dev reference post debugfs use. void wwan_put_debugfs_dir(struct dentry *dir) Signed-off-by: M Chetan Kumar Signed-off-by: David S. Miller --- drivers/net/wwan/wwan_core.c | 36 ++++++++++++++++++++++++++++++++++++ include/linux/wwan.h | 2 ++ 2 files changed, 38 insertions(+) diff --git a/drivers/net/wwan/wwan_core.c b/drivers/net/wwan/wwan_core.c index 1508dc2a497b..b8c7843730ed 100644 --- a/drivers/net/wwan/wwan_core.c +++ b/drivers/net/wwan/wwan_core.c @@ -160,6 +160,42 @@ struct dentry *wwan_get_debugfs_dir(struct device *parent) return wwandev->debugfs_dir; } EXPORT_SYMBOL_GPL(wwan_get_debugfs_dir); + +static int wwan_dev_debugfs_match(struct device *dev, const void *dir) +{ + struct wwan_device *wwandev; + + if (dev->type != &wwan_dev_type) + return 0; + + wwandev = to_wwan_dev(dev); + + return wwandev->debugfs_dir == dir; +} + +static struct wwan_device *wwan_dev_get_by_debugfs(struct dentry *dir) +{ + struct device *dev; + + dev = class_find_device(wwan_class, NULL, dir, wwan_dev_debugfs_match); + if (!dev) + return ERR_PTR(-ENODEV); + + return to_wwan_dev(dev); +} + +void wwan_put_debugfs_dir(struct dentry *dir) +{ + struct wwan_device *wwandev = wwan_dev_get_by_debugfs(dir); + + if (WARN_ON(IS_ERR(wwandev))) + return; + + /* wwan_dev_get_by_debugfs() also got a reference */ + put_device(&wwandev->dev); + put_device(&wwandev->dev); +} +EXPORT_SYMBOL_GPL(wwan_put_debugfs_dir); #endif /* This function allocates and registers a new WWAN device OR if a WWAN device diff --git a/include/linux/wwan.h b/include/linux/wwan.h index afb3334ec8c5..5ce2acf444fb 100644 --- a/include/linux/wwan.h +++ b/include/linux/wwan.h @@ -174,11 +174,13 @@ void wwan_unregister_ops(struct device *parent); #ifdef CONFIG_WWAN_DEBUGFS struct dentry *wwan_get_debugfs_dir(struct device *parent); +void wwan_put_debugfs_dir(struct dentry *dir); #else static inline struct dentry *wwan_get_debugfs_dir(struct device *parent) { return ERR_PTR(-ENODEV); } +static inline void wwan_put_debugfs_dir(struct dentry *dir) {} #endif #endif /* __WWAN_H */ -- cgit v1.2.3 From 163f69ae22e5244ba69af7ed7b024f59f96d5437 Mon Sep 17 00:00:00 2001 From: M Chetan Kumar Date: Mon, 14 Feb 2022 12:46:53 +0530 Subject: net: wwan: iosm: drop debugfs dev reference Post debugfs use call wwan_put_debugfs_dir()to drop debugfs dev reference. Signed-off-by: M Chetan Kumar Signed-off-by: David S. Miller --- drivers/net/wwan/iosm/iosm_ipc_debugfs.c | 5 +++-- drivers/net/wwan/iosm/iosm_ipc_imem.h | 2 ++ 2 files changed, 5 insertions(+), 2 deletions(-) diff --git a/drivers/net/wwan/iosm/iosm_ipc_debugfs.c b/drivers/net/wwan/iosm/iosm_ipc_debugfs.c index f2f57751a7d2..e916139b8cd4 100644 --- a/drivers/net/wwan/iosm/iosm_ipc_debugfs.c +++ b/drivers/net/wwan/iosm/iosm_ipc_debugfs.c @@ -12,10 +12,10 @@ void ipc_debugfs_init(struct iosm_imem *ipc_imem) { - struct dentry *debugfs_pdev = wwan_get_debugfs_dir(ipc_imem->dev); + ipc_imem->debugfs_wwan_dir = wwan_get_debugfs_dir(ipc_imem->dev); ipc_imem->debugfs_dir = debugfs_create_dir(KBUILD_MODNAME, - debugfs_pdev); + ipc_imem->debugfs_wwan_dir); ipc_imem->trace = ipc_trace_init(ipc_imem); if (!ipc_imem->trace) @@ -26,4 +26,5 @@ void ipc_debugfs_deinit(struct iosm_imem *ipc_imem) { ipc_trace_deinit(ipc_imem->trace); debugfs_remove_recursive(ipc_imem->debugfs_dir); + wwan_put_debugfs_dir(ipc_imem->debugfs_wwan_dir); } diff --git a/drivers/net/wwan/iosm/iosm_ipc_imem.h b/drivers/net/wwan/iosm/iosm_ipc_imem.h index 5682e8d6be7b..e700dc8bfe0a 100644 --- a/drivers/net/wwan/iosm/iosm_ipc_imem.h +++ b/drivers/net/wwan/iosm/iosm_ipc_imem.h @@ -341,6 +341,7 @@ enum ipc_phase { * @ev_mux_net_transmit_pending:0 means inform the IPC tasklet to pass * @reset_det_n: Reset detect flag * @pcie_wake_n: Pcie wake flag + * @debugfs_wwan_dir: WWAN Debug FS directory entry * @debugfs_dir: Debug FS directory for driver-specific entries */ struct iosm_imem { @@ -384,6 +385,7 @@ struct iosm_imem { reset_det_n:1, pcie_wake_n:1; #ifdef CONFIG_WWAN_DEBUGFS + struct dentry *debugfs_wwan_dir; struct dentry *debugfs_dir; #endif }; -- cgit v1.2.3