bpf: Eliminate rlimit-based memory accounting for sockmap and sockhash maps

Do not use rlimit-based memory accounting for sockmap and sockhash maps.
It has been replaced with the memcg-based memory accounting.
Signed-off-by: Roman Gushchin <guro@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20201201215900.3569844-29-guro@fb.com

net/core/sock_map.c

@@ -27,8 +27,6 @@ struct bpf_stab {
 static struct bpf_map *sock_map_alloc(union bpf_attr *attr)
 {
 	struct bpf_stab *stab;
-	u64 cost;
-	int err;
 
 	if (!capable(CAP_NET_ADMIN))
 		return ERR_PTR(-EPERM);
@@ -46,22 +44,15 @@ static struct bpf_map *sock_map_alloc(union bpf_attr *attr)
 	bpf_map_init_from_attr(&stab->map, attr);
 	raw_spin_lock_init(&stab->lock);
 
-	/* Make sure page count doesn't overflow. */
-	cost = (u64) stab->map.max_entries * sizeof(struct sock *);
-	err = bpf_map_charge_init(&stab->map.memory, cost);
-	if (err)
-		goto free_stab;
-
 	stab->sks = bpf_map_area_alloc(stab->map.max_entries *
 				       sizeof(struct sock *),
 				       stab->map.numa_node);
-	if (stab->sks)
-		return &stab->map;
-	err = -ENOMEM;
-	bpf_map_charge_finish(&stab->map.memory);
-free_stab:
+	if (!stab->sks) {
 		kfree(stab);
-	return ERR_PTR(err);
+		return ERR_PTR(-ENOMEM);
+	}
+
+	return &stab->map;
 }
 
 int sock_map_get_from_fd(const union bpf_attr *attr, struct bpf_prog *prog)
@@ -1104,7 +1095,6 @@ static struct bpf_map *sock_hash_alloc(union bpf_attr *attr)
 {
 	struct bpf_shtab *htab;
 	int i, err;
-	u64 cost;
 
 	if (!capable(CAP_NET_ADMIN))
 		return ERR_PTR(-EPERM);
@@ -1132,21 +1122,10 @@ static struct bpf_map *sock_hash_alloc(union bpf_attr *attr)
 		goto free_htab;
 	}
 
-	cost = (u64) htab->buckets_num * sizeof(struct bpf_shtab_bucket) +
-	       (u64) htab->elem_size * htab->map.max_entries;
-	if (cost >= U32_MAX - PAGE_SIZE) {
-		err = -EINVAL;
-		goto free_htab;
-	}
-	err = bpf_map_charge_init(&htab->map.memory, cost);
-	if (err)
-		goto free_htab;
-
 	htab->buckets = bpf_map_area_alloc(htab->buckets_num *
 					   sizeof(struct bpf_shtab_bucket),
 					   htab->map.numa_node);
 	if (!htab->buckets) {
-		bpf_map_charge_finish(&htab->map.memory);
 		err = -ENOMEM;
 		goto free_htab;
 	}