net: allow sleeping when modifying store_rps_map

Commit 10e4ea7 ("net: Fix race condition in store_rps_map") has moved the
manipulation of the rps_needed jump label under a spinlock. Since changing
the state of a jump label may sleep this is incorrect and causes warnings
during runtime.

Make rps_map_lock a mutex to allow sleeping under it.

Fixes: 10e4ea7 ("net: Fix race condition in store_rps_map")
Signed-off-by: Sasha Levin <[email protected]>
Acked-by: Tom Herbert <[email protected]>
Signed-off-by: David S. Miller <[email protected]>

Author: sashalevin

net/core/net-sysfs.c

@@ -689,7 +689,7 @@ static ssize_t store_rps_map(struct netdev_rx_queue *queue,
 	struct rps_map *old_map, *map;
 	cpumask_var_t mask;
 	int err, cpu, i;
-	static DEFINE_SPINLOCK(rps_map_lock);
+	static DEFINE_MUTEX(rps_map_mutex);
 
 	if (!capable(CAP_NET_ADMIN))
 		return -EPERM;
@@ -722,17 +722,17 @@ static ssize_t store_rps_map(struct netdev_rx_queue *queue,
 		map = NULL;
 	}
 
-	spin_lock(&rps_map_lock);
+	mutex_lock(&rps_map_mutex);
 	old_map = rcu_dereference_protected(queue->rps_map,
-					    lockdep_is_held(&rps_map_lock));
+					    mutex_is_locked(&rps_map_mutex));
 	rcu_assign_pointer(queue->rps_map, map);
 
 	if (map)
 		static_key_slow_inc(&rps_needed);
 	if (old_map)
 		static_key_slow_dec(&rps_needed);
 
-	spin_unlock(&rps_map_lock);
+	mutex_unlock(&rps_map_mutex);
 
 	if (old_map)
 		kfree_rcu(old_map, rcu);