diff --git a/include/linux/bpf.h b/include/linux/bpf.h index 3496977203a3..263598619f90 100644 --- a/include/linux/bpf.h +++ b/include/linux/bpf.h @@ -25,6 +25,7 @@ struct bpf_map; /* map is generic key/value storage optionally accesible by eBPF programs */ struct bpf_map_ops { /* funcs callable from userspace (via syscall) */ + int (*map_alloc_check)(union bpf_attr *attr); struct bpf_map *(*map_alloc)(union bpf_attr *attr); void (*map_release)(struct bpf_map *map, struct file *map_file); void (*map_free)(struct bpf_map *map); diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c index 2bac0dc8baba..c0ac03a04880 100644 --- a/kernel/bpf/syscall.c +++ b/kernel/bpf/syscall.c @@ -96,16 +96,25 @@ static int check_uarg_tail_zero(void __user *uaddr, static struct bpf_map *find_and_alloc_map(union bpf_attr *attr) { + const struct bpf_map_ops *ops; struct bpf_map *map; + int err; - if (attr->map_type >= ARRAY_SIZE(bpf_map_types) || - !bpf_map_types[attr->map_type]) + if (attr->map_type >= ARRAY_SIZE(bpf_map_types)) + return ERR_PTR(-EINVAL); + ops = bpf_map_types[attr->map_type]; + if (!ops) return ERR_PTR(-EINVAL); - map = bpf_map_types[attr->map_type]->map_alloc(attr); + if (ops->map_alloc_check) { + err = ops->map_alloc_check(attr); + if (err) + return ERR_PTR(err); + } + map = ops->map_alloc(attr); if (IS_ERR(map)) return map; - map->ops = bpf_map_types[attr->map_type]; + map->ops = ops; map->map_type = attr->map_type; return map; }