bpf: Move check_uarg_tail_zero() upward

The function check_uarg_tail_zero() may be useful for other part of the
code in the syscall.c file. Move this function at the beginning of the
file.

Signed-off-by: Mickaël Salaün <mic@digikod.net>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: David S. Miller <davem@davemloft.net>
Cc: Kees Cook <keescook@chromium.org>
Cc: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index 6c772ad..c653ee0 100644 (file)
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c
@@ -48,6 +48,32 @@ static const struct bpf_map_ops * const bpf_map_types[] = {
 #undef BPF_MAP_TYPE
 };
 
+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 struct bpf_map *find_and_alloc_map(union bpf_attr *attr)
 {
        struct bpf_map *map;
@@ -1246,32 +1272,6 @@ 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)