@@ -66,8 +66,6 @@ struct bpf_prog_aux;
/* BPF program can access up to 512 bytes of stack space. */
#define MAX_BPF_STACK 512
-#define BPF_TAG_SIZE 8
-
/* Helper macros for filter block array initializers. */
/* ALU ops on registers, bpf_add|sub|...: dst_reg += src_reg */
@@ -86,6 +86,7 @@ enum bpf_cmd {
BPF_MAP_GET_NEXT_ID,
BPF_PROG_GET_FD_BY_ID,
BPF_MAP_GET_FD_BY_ID,
+ BPF_OBJ_GET_INFO_BY_FD,
};
enum bpf_map_type {
@@ -222,6 +223,12 @@ union bpf_attr {
};
__u32 next_id;
};
+
+ struct { /* anonymous struct used by BPF_OBJ_GET_INFO_BY_FD */
+ __u32 bpf_fd;
+ __u32 info_len;
+ __aligned_u64 info;
+ } info;
} __attribute__((aligned(8)));
/* BPF helper function descriptions:
@@ -683,4 +690,25 @@ struct xdp_md {
__u32 data_end;
};
+#define BPF_TAG_SIZE 8
+
+struct bpf_prog_info {
+ __u32 type;
+ __u32 id;
+ __u8 tag[BPF_TAG_SIZE];
+ __u32 jited_prog_len;
+ __u32 xlated_prog_len;
+ __aligned_u64 jited_prog_insns;
+ __aligned_u64 xlated_prog_insns;
+} __attribute__((aligned(8)));
+
+struct bpf_map_info {
+ __u32 type;
+ __u32 id;
+ __u32 key_size;
+ __u32 value_size;
+ __u32 max_entries;
+ __u32 map_flags;
+} __attribute__((aligned(8)));
+
#endif /* _UAPI__LINUX_BPF_H__ */
@@ -1237,6 +1237,145 @@ static int bpf_map_get_fd_by_id(const union bpf_attr *attr)
return fd;
}
+static int check_uarg_tail_zero(void __user *uaddr,
+ size_t expected_size,
+ size_t actual_size)
+{
+ unsigned char __user *addr;
+ unsigned char __user *end;
+ unsigned char val;
+ int err;
+
+ if (actual_size <= expected_size)
+ return 0;
+
+ addr = uaddr + expected_size;
+ end = uaddr + actual_size;
+
+ for (; addr < end; addr++) {
+ err = get_user(val, addr);
+ if (err)
+ return err;
+ if (val)
+ return -E2BIG;
+ }
+
+ return 0;
+}
+
+static int bpf_prog_get_info_by_fd(struct bpf_prog *prog,
+ const union bpf_attr *attr,
+ union bpf_attr __user *uattr)
+{
+ struct bpf_prog_info __user *uinfo = u64_to_user_ptr(attr->info.info);
+ struct bpf_prog_info info = {};
+ u32 info_len = attr->info.info_len;
+ char __user *uinsns;
+ u32 ulen;
+ int err;
+
+ err = check_uarg_tail_zero(uinfo, sizeof(info), info_len);
+ if (err)
+ return err;
+ info_len = min_t(u32, sizeof(info), info_len);
+
+ if (copy_from_user(&info, uinfo, info_len))
+ return err;
+
+ info.type = prog->type;
+ info.id = prog->aux->id;
+
+ memcpy(info.tag, prog->tag, sizeof(prog->tag));
+
+ if (!capable(CAP_SYS_ADMIN)) {
+ info.jited_prog_len = 0;
+ info.xlated_prog_len = 0;
+ goto done;
+ }
+
+ ulen = info.jited_prog_len;
+ info.jited_prog_len = prog->jited_len;
+ if (info.jited_prog_len && ulen) {
+ uinsns = u64_to_user_ptr(info.jited_prog_insns);
+ ulen = min_t(u32, info.jited_prog_len, ulen);
+ if (copy_to_user(uinsns, prog->bpf_func, ulen))
+ return -EFAULT;
+ }
+
+ ulen = info.xlated_prog_len;
+ info.xlated_prog_len = bpf_prog_size(prog->len);
+ if (info.xlated_prog_len && ulen) {
+ uinsns = u64_to_user_ptr(info.xlated_prog_insns);
+ ulen = min_t(u32, info.xlated_prog_len, ulen);
+ if (copy_to_user(uinsns, prog->insnsi, ulen))
+ return -EFAULT;
+ }
+
+done:
+ if (copy_to_user(uinfo, &info, info_len) ||
+ put_user(info_len, &uattr->info.info_len))
+ return -EFAULT;
+
+ return 0;
+}
+
+static int bpf_map_get_info_by_fd(struct bpf_map *map,
+ const union bpf_attr *attr,
+ union bpf_attr __user *uattr)
+{
+ struct bpf_map_info __user *uinfo = u64_to_user_ptr(attr->info.info);
+ struct bpf_map_info info = {};
+ u32 info_len = attr->info.info_len;
+ int err;
+
+ err = check_uarg_tail_zero(uinfo, sizeof(info), info_len);
+ if (err)
+ return err;
+ info_len = min_t(u32, sizeof(info), info_len);
+
+ info.type = map->map_type;
+ info.id = map->id;
+ info.key_size = map->key_size;
+ info.value_size = map->value_size;
+ info.max_entries = map->max_entries;
+ info.map_flags = map->map_flags;
+
+ if (copy_to_user(uinfo, &info, info_len) ||
+ put_user(info_len, &uattr->info.info_len))
+ return -EFAULT;
+
+ return 0;
+}
+
+#define BPF_OBJ_GET_INFO_BY_FD_LAST_FIELD info.info
+
+static int bpf_obj_get_info_by_fd(const union bpf_attr *attr,
+ union bpf_attr __user *uattr)
+{
+ int ufd = attr->info.bpf_fd;
+ struct fd f;
+ int err;
+
+ if (CHECK_ATTR(BPF_OBJ_GET_INFO_BY_FD))
+ return -EINVAL;
+
+ f = fdget(ufd);
+ if (!f.file)
+ return -EBADFD;
+
+ if (f.file->f_op == &bpf_prog_fops)
+ err = bpf_prog_get_info_by_fd(f.file->private_data, attr,
+ uattr);
+ else if (f.file->f_op == &bpf_map_fops)
+ err = bpf_map_get_info_by_fd(f.file->private_data, attr,
+ uattr);
+ else
+ err = -EINVAL;
+
+ fdput(f);
+ return err;
+}
+
SYSCALL_DEFINE3(bpf, int, cmd, union bpf_attr __user *, uattr, unsigned int, size)
{
union bpf_attr attr = {};
@@ -1256,23 +1395,10 @@ SYSCALL_DEFINE3(bpf, int, cmd, union bpf_attr __user *, uattr, unsigned int, siz
* user-space does not rely on any kernel feature
* extensions we dont know about yet.
*/
- if (size > sizeof(attr)) {
- unsigned char __user *addr;
- unsigned char __user *end;
- unsigned char val;
-
- addr = (void __user *)uattr + sizeof(attr);
- end = (void __user *)uattr + size;
-
- for (; addr < end; addr++) {
- err = get_user(val, addr);
- if (err)
- return err;
- if (val)
- return -E2BIG;
- }
- size = sizeof(attr);
- }
+ err = check_uarg_tail_zero(uattr, sizeof(attr), size);
+ if (err)
+ return err;
+ size = min_t(u32, size, sizeof(attr));
/* copy attributes from user space, may be less than sizeof(bpf_attr) */
if (copy_from_user(&attr, uattr, size) != 0)
@@ -1328,6 +1454,9 @@ SYSCALL_DEFINE3(bpf, int, cmd, union bpf_attr __user *, uattr, unsigned int, siz
case BPF_MAP_GET_FD_BY_ID:
err = bpf_map_get_fd_by_id(&attr);
break;
+ case BPF_OBJ_GET_INFO_BY_FD:
+ err = bpf_obj_get_info_by_fd(&attr, uattr);
+ break;
default:
err = -EINVAL;
break;