On Mon, Jun 5, 2023 at 1:05 PM David Vernet <void@xxxxxxxxxxxxx> wrote: > > + > +static __u64 set_invoked(struct bpf_map *map, __u64 *key, __u64 *val, struct callback_ctx *ctx) > +{ > + struct bpf_map *inner_map; > + > + ctx->invoked = true; > + inner_map = bpf_map_lookup_elem(map, key); > + if (!inner_map) { > + ctx->failed = true; > + return 1; > + } This doesn't look right. 'val' is not 'u64 *'. It probably should be 'struct bpf_map *', so lookup shouldn't be necessary. map_set_for_each_callback_args() just sets it to PTR_TO_MAP_VALUE. It probably should be CONST_PTR_TO_MAP. Also for normal hash map for_each_elem 'val' is writeable. It shouldn't be in this case. So to cleanly support iterating hash_of_maps patch 1 needs more work.