bpf: Eliminate rlimit-based memory accounting for bpf_struct_ops maps

Do not use rlimit-based memory accounting for bpf_struct_ops 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/20201201215900.3569844-20-guro@fb.com

kernel/bpf/bpf_struct_ops.c

@@ -548,12 +548,10 @@ static int bpf_struct_ops_map_alloc_check(union bpf_attr *attr)
 static struct bpf_map *bpf_struct_ops_map_alloc(union bpf_attr *attr)
 {
 	const struct bpf_struct_ops *st_ops;
-	size_t map_total_size, st_map_size;
+	size_t st_map_size;
 	struct bpf_struct_ops_map *st_map;
 	const struct btf_type *t, *vt;
-	struct bpf_map_memory mem;
 	struct bpf_map *map;
-	int err;
 
 	if (!bpf_capable())
 		return ERR_PTR(-EPERM);
@@ -573,20 +571,11 @@ static struct bpf_map *bpf_struct_ops_map_alloc(union bpf_attr *attr)
 		 * struct bpf_struct_ops_tcp_congestions_ops
 		 */
 		(vt->size - sizeof(struct bpf_struct_ops_value));
-	map_total_size = st_map_size +
-		/* uvalue */
-		sizeof(vt->size) +
-		/* struct bpf_progs **progs */
-		 btf_type_vlen(t) * sizeof(struct bpf_prog *);
-	err = bpf_map_charge_init(&mem, map_total_size);
-	if (err < 0)
-		return ERR_PTR(err);
 
 	st_map = bpf_map_area_alloc(st_map_size, NUMA_NO_NODE);
-	if (!st_map) {
-		bpf_map_charge_finish(&mem);
+	if (!st_map)
 		return ERR_PTR(-ENOMEM);
-	}
+
 	st_map->st_ops = st_ops;
 	map = &st_map->map;
 
@@ -597,14 +586,12 @@ static struct bpf_map *bpf_struct_ops_map_alloc(union bpf_attr *attr)
 	st_map->image = bpf_jit_alloc_exec(PAGE_SIZE);
 	if (!st_map->uvalue || !st_map->progs || !st_map->image) {
 		bpf_struct_ops_map_free(map);
-		bpf_map_charge_finish(&mem);
 		return ERR_PTR(-ENOMEM);
 	}
 
 	mutex_init(&st_map->lock);
 	set_vm_flush_reset_perms(st_map->image);
 	bpf_map_init_from_attr(map, attr);
-	bpf_map_charge_move(&map->memory, &mem);
 
 	return map;
 }