[PATCH] net: wan: lapbether.c: Use built-in RCU list checking

From: madhuparnabhowmik04
Date: Wed Jan 15 2020 - 06:41:19 EST


From: Madhuparna Bhowmik <madhuparnabhowmik04@xxxxxxxxx>

The only callers of the function lapbeth_get_x25_dev()
are lapbeth_rcv() and lapbeth_device_event().

lapbeth_rcv() uses rcu_read_lock() whereas lapbeth_device_event()
is called with RTNL held (As mentioned in the comments).

Therefore, pass lockdep_rtnl_is_held() as cond argument in
list_for_each_entry_rcu();

Signed-off-by: Madhuparna Bhowmik <madhuparnabhowmik04@xxxxxxxxx>
---
drivers/net/wan/lapbether.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/wan/lapbether.c b/drivers/net/wan/lapbether.c
index 0f1217b506ad..e30d91a38cfb 100644
--- a/drivers/net/wan/lapbether.c
+++ b/drivers/net/wan/lapbether.c
@@ -64,7 +64,7 @@ static struct lapbethdev *lapbeth_get_x25_dev(struct net_device *dev)
{
struct lapbethdev *lapbeth;

- list_for_each_entry_rcu(lapbeth, &lapbeth_devices, node) {
+ list_for_each_entry_rcu(lapbeth, &lapbeth_devices, node, lockdep_rtnl_is_held()) {
if (lapbeth->ethdev == dev)
return lapbeth;
}
--
2.17.1