bpf: add memlock precharge check for cgroup_local_storage

ANBZ: torvalds#26

commit ffc8b14 upstream

Cgroup local storage maps lack the memlock precharge check,
which is performed before the memory allocation for
most other bpf map types.

Let's add it in order to unify all map types.

Signed-off-by: Roman Gushchin <guro@fb.com>
Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Qiao Ma <mqaio@linux.alibaba.com>
Acked-by: Tony Lu <tonylu@linux.alibaba.com>

kernel/bpf/local_storage.c

@@ -192,6 +192,8 @@ static struct bpf_map *cgroup_storage_map_alloc(union bpf_attr *attr)
 {
 	int numa_node = bpf_map_attr_numa_node(attr);
 	struct bpf_cgroup_storage_map *map;
+	u32 pages;
+	int ret;
 
 	if (attr->key_size != sizeof(struct bpf_cgroup_storage_key))
 		return ERR_PTR(-EINVAL);
@@ -210,13 +212,18 @@ static struct bpf_map *cgroup_storage_map_alloc(union bpf_attr *attr)
 		/* max_entries is not used and enforced to be 0 */
 		return ERR_PTR(-EINVAL);
 
+	pages = round_up(sizeof(struct bpf_cgroup_storage_map), PAGE_SIZE) >>
+		PAGE_SHIFT;
+	ret = bpf_map_precharge_memlock(pages);
+	if (ret < 0)
+		return ERR_PTR(ret);
+
 	map = kmalloc_node(sizeof(struct bpf_cgroup_storage_map),
 			   __GFP_ZERO | GFP_USER, numa_node);
 	if (!map)
 		return ERR_PTR(-ENOMEM);
 
-	map->map.pages = round_up(sizeof(struct bpf_cgroup_storage_map),
-				  PAGE_SIZE) >> PAGE_SHIFT;
+	map->map.pages = pages;
 
 	/* copy mandatory map attributes */
 	bpf_map_init_from_attr(&map->map, attr);