[PATCH v2 3/3] staging: rtl8192u: fix rmmod warn when wlan0 is renamed

Tong Zhang
2022-07-19T05:52:38Z

This driver creates 4 debug files under [devname] folder. The devname
could be wlan0 initially, however it could be renamed later to e.g.
enx00e04c00000. This will cause problem during debug file teardown since
it uses netdev->name which is no longer wlan0. To solve this problem,
add a notifier to handle device renaming.

Reported-by: Zheyu Ma <zheyuma97@gmail.com>
Tested-by: Zheyu Ma <zheyuma97@gmail.com>
Signed-off-by: Tong Zhang <ztong0001@gmail.com>
---
drivers/staging/rtl8192u/r8192U.h | 1 +
drivers/staging/rtl8192u/r8192U_core.c | 35 ++++++++++++++++++++++-
drivers/staging/rtl8192u/r8192U_debugfs.c | 13 +++++++++
3 files changed, 48 insertions(+), 1 deletion(-)

diff --git a/drivers/staging/rtl8192u/r8192U.h b/drivers/staging/rtl8192u/r8192U.h
index e8860bb2b607..ccce37b7e2ae 100644
--- a/drivers/staging/rtl8192u/r8192U.h
+++ b/drivers/staging/rtl8192u/r8192U.h
@@ -1122,4 +1122,5 @@ void setKey(struct net_device *dev, u8 EntryNo, u8 KeyIndex, u16 KeyType,

void rtl8192_debugfs_init(struct net_device *dev);
void rtl8192_debugfs_exit(struct net_device *dev);
+void rtl8192_debugfs_rename(struct net_device *dev);
#endif
diff --git a/drivers/staging/rtl8192u/r8192U_core.c b/drivers/staging/rtl8192u/r8192U_core.c
index ac3716550505..5cc78c5bd706 100644
--- a/drivers/staging/rtl8192u/r8192U_core.c
+++ b/drivers/staging/rtl8192u/r8192U_core.c
@@ -4606,6 +4606,30 @@ static void rtl8192_usb_disconnect(struct usb_interface *intf)
RT_TRACE(COMP_DOWN, "wlan driver removed\n");
}

+static int rtl8192_usb_netdev_event(struct notifier_block *nb, unsigned long event,
+ void *data)
+{
+ struct net_device *netdev = netdev_notifier_info_to_dev(data);
+
+ if (netdev->netdev_ops != &rtl8192_netdev_ops)
+ goto out;
+
+ switch (event) {
+ case NETDEV_CHANGENAME:
+ rtl8192_debugfs_rename(netdev);
+ break;
+ default:
+ break;
+ }
+
+out:
+ return NOTIFY_DONE;
+}
+
+static struct notifier_block rtl8192_usb_netdev_notifier = {
+ .notifier_call = rtl8192_usb_netdev_event,
+};
+
static int __init rtl8192_usb_module_init(void)
{
int ret;
@@ -4615,10 +4639,16 @@ static int __init rtl8192_usb_module_init(void)
RT_TRACE(COMP_INIT, "Initializing module");
RT_TRACE(COMP_INIT, "Wireless extensions version %d", WIRELESS_EXT);

+ ret = register_netdevice_notifier(&rtl8192_usb_netdev_notifier);
+ if (ret) {
+ pr_err("register_netdevice_notifier failed %d\n", ret);
+ return ret;
+ }
+
ret = ieee80211_debug_init();
if (ret) {
pr_err("ieee80211_debug_init() failed %d\n", ret);
- return ret;
+ goto unregister_notifier;
}

ret = ieee80211_crypto_init();
@@ -4660,6 +4690,8 @@ static int __init rtl8192_usb_module_init(void)
ieee80211_crypto_deinit();
debug_exit:
ieee80211_debug_exit();
+unregister_notifier:
+ unregister_netdevice_notifier(&rtl8192_usb_netdev_notifier);
return ret;
}

@@ -4671,6 +4703,7 @@ static void __exit rtl8192_usb_module_exit(void)
ieee80211_crypto_tkip_exit();
ieee80211_crypto_deinit();
ieee80211_debug_exit();
+ unregister_netdevice_notifier(&rtl8192_usb_netdev_notifier);
RT_TRACE(COMP_DOWN, "Exiting");
}

diff --git a/drivers/staging/rtl8192u/r8192U_debugfs.c b/drivers/staging/rtl8192u/r8192U_debugfs.c
index 5c9376e50889..c94f5dfac96b 100644
--- a/drivers/staging/rtl8192u/r8192U_debugfs.c
+++ b/drivers/staging/rtl8192u/r8192U_debugfs.c
@@ -173,3 +173,16 @@ void rtl8192_debugfs_exit(struct net_device *dev)
priv->debugfs_dir = NULL;
}

+void rtl8192_debugfs_rename(struct net_device *dev)
+{
+ struct r8192_priv *priv = (struct r8192_priv *)ieee80211_priv(dev);
+
+ if (!priv->debugfs_dir)
+ return;
+
+ if (!strcmp(priv->debugfs_dir->d_name.name, dev->name))
+ return;
+
+ debugfs_rename(priv->debugfs_dir->d_parent, priv->debugfs_dir,
+ priv->debugfs_dir->d_parent, dev->name);
+}
--
2.25.1