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?
