Martin KaFai Lau [off-list ref] writes:

On Tue, Jun 15, 2021 at 04:54:42PM +0200, Toke Høiland-Jørgensen wrote:
[ ... ]

quoted

 static void *__dev_map_hash_lookup_elem(struct bpf_map *map, u32 key)
 {
 	struct bpf_dtab *dtab = container_of(map, struct bpf_dtab, map);

@@ -266,7 +270,8 @@ static void *__dev_map_hash_lookup_elem(struct bpf_map *map, u32 key)
 	struct bpf_dtab_netdev *dev;
 
 	hlist_for_each_entry_rcu(dev, head, index_hlist,
-				 lockdep_is_held(&dtab->index_lock))
+				 (lockdep_is_held(&dtab->index_lock) ||
+				  rcu_read_lock_bh_held()))

This change is not needed also.

Ah yes, of course - my bad for forgetting to remove that as well. Will
send a v3!

-Toke