[PATCH AUTOSEL 5.4 034/134] leds: trigger: netdev: fix handling on interface rename

Sasha Levin
2019-12-11T16:07:29Z

From: Martin Schiller <ms@dev.tdt.de>

[ Upstream commit 5f820ed52371b4f5d8c43c93f03408d0dbc01e5b ]

The NETDEV_CHANGENAME code is not "unneeded" like it is stated in commit
4cb6560514fa ("leds: trigger: netdev: fix refcnt leak on interface
rename").

The event was accidentally misinterpreted equivalent to
NETDEV_UNREGISTER, but should be equivalent to NETDEV_REGISTER.

This was the case in the original code from the openwrt project.

Otherwise, you are unable to set netdev led triggers for (non-existent)
netdevices, which has to be renamed. This is the case, for example, for
ppp interfaces in openwrt.

Fixes: 06f502f57d0d ("leds: trigger: Introduce a NETDEV trigger")
Fixes: 4cb6560514fa ("leds: trigger: netdev: fix refcnt leak on interface rename")
Signed-off-by: Martin Schiller <ms@dev.tdt.de>
Signed-off-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/leds/trigger/ledtrig-netdev.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/leds/trigger/ledtrig-netdev.c b/drivers/leds/trigger/ledtrig-netdev.c
index 136f86a1627d1..d5e774d830215 100644
--- a/drivers/leds/trigger/ledtrig-netdev.c
+++ b/drivers/leds/trigger/ledtrig-netdev.c
@@ -302,10 +302,12 @@ static int netdev_trig_notify(struct notifier_block *nb,
container_of(nb, struct led_netdev_data, notifier);

if (evt != NETDEV_UP && evt != NETDEV_DOWN && evt != NETDEV_CHANGE
- && evt != NETDEV_REGISTER && evt != NETDEV_UNREGISTER)
+ && evt != NETDEV_REGISTER && evt != NETDEV_UNREGISTER
+ && evt != NETDEV_CHANGENAME)
return NOTIFY_DONE;

if (!(dev == trigger_data->net_dev ||
+ (evt == NETDEV_CHANGENAME && !strcmp(dev->name, trigger_data->device_name)) ||
(evt == NETDEV_REGISTER && !strcmp(dev->name, trigger_data->device_name))))
return NOTIFY_DONE;

@@ -315,6 +317,7 @@ static int netdev_trig_notify(struct notifier_block *nb,

clear_bit(NETDEV_LED_MODE_LINKUP, &trigger_data->mode);
switch (evt) {
+ case NETDEV_CHANGENAME:
case NETDEV_REGISTER:
if (trigger_data->net_dev)
dev_put(trigger_data->net_dev);
--
2.20.1