BPF_MAP_KEY_POISON
bpf_map_key_store(aux, BPF_MAP_KEY_POISON);
bpf_map_key_store(aux, BPF_MAP_KEY_POISON);
return aux->map_key_state & BPF_MAP_KEY_POISON;
return aux->map_key_state & ~(BPF_MAP_KEY_SEEN | BPF_MAP_KEY_POISON);
(poisoned ? BPF_MAP_KEY_POISON : 0ULL);