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bpf: grab rcu read lock for bpf_percpu_hash_update
authorSasha Levin <sasha.levin@oracle.com>
Fri, 19 Feb 2016 18:53:10 +0000 (13:53 -0500)
committerDavid S. Miller <davem@davemloft.net>
Fri, 19 Feb 2016 19:37:43 +0000 (14:37 -0500)
bpf_percpu_hash_update() expects rcu lock to be held and warns if it's not,
which pointed out a missing rcu read lock.

Fixes: 15a07b338 ("bpf: add lookup/update support for per-cpu hash and array maps")
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
kernel/bpf/hashtab.c

index fd5db8f..a68e951 100644 (file)
@@ -619,7 +619,13 @@ out:
 int bpf_percpu_hash_update(struct bpf_map *map, void *key, void *value,
                           u64 map_flags)
 {
-       return __htab_percpu_map_update_elem(map, key, value, map_flags, true);
+       int ret;
+
+       rcu_read_lock();
+       ret = __htab_percpu_map_update_elem(map, key, value, map_flags, true);
+       rcu_read_unlock();
+
+       return ret;
 }
 
 static const struct bpf_map_ops htab_percpu_ops = {