Martin KaFai Lau <kafai@xxxxxx> writes:
> On Tue, Jun 29, 2021 at 01:00:51AM +0200, Toke Høiland-Jørgensen wrote:
>> There were a couple of READ_ONCE()-invocations left-over by the devmap RCU
>> conversion. Convert these to rcu_dereference() as well to avoid complaints
>> from sparse.
>>
>> Fixes: 782347b6bcad ("xdp: Add proper __rcu annotations to redirect map entries")
>> Reported-by: kernel test robot <lkp@xxxxxxxxx>
>> Signed-off-by: Toke Høiland-Jørgensen <toke@xxxxxxxxxx>
>> ---
>> kernel/bpf/devmap.c | 4 ++--
>> 1 file changed, 2 insertions(+), 2 deletions(-)
>>
>> diff --git a/kernel/bpf/devmap.c b/kernel/bpf/devmap.c
>> index 2f6bd75cd682..7a0c008f751b 100644
>> --- a/kernel/bpf/devmap.c
>> +++ b/kernel/bpf/devmap.c
>> @@ -558,7 +558,7 @@ int dev_map_enqueue_multi(struct xdp_buff *xdp, struct net_device *dev_rx,
>>
>> if (map->map_type == BPF_MAP_TYPE_DEVMAP) {
>> for (i = 0; i < map->max_entries; i++) {
>> - dst = READ_ONCE(dtab->netdev_map[i]);
>> + dst = rcu_dereference(dtab->netdev_map[i]);
> __dev_map_lookup_elem() uses rcu_dereference_check(dtab->netdev_map[key], rcu_read_lock_bh_held()).
> It is not needed here?
Hmm, I somehow managed to convince myself last night that it wasn't, but
looking at it again now I think you're right. Will send a v2.
-Toke
