[PATCH net-next v1 1/2] bpf: Move check_uarg_tail_zero() upward

From: MickaÃl SalaÃn
Date: Mon Aug 07 2017 - 12:37:07 EST


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: MickaÃl SalaÃn <mic@xxxxxxxxxxx>
Cc: Alexei Starovoitov <ast@xxxxxxxxxx>
Cc: Daniel Borkmann <daniel@xxxxxxxxxxxxx>
Cc: David S. Miller <davem@xxxxxxxxxxxxx>
Cc: Kees Cook <keescook@xxxxxxxxxxxx>
Cc: Martin KaFai Lau <kafai@xxxxxx>
---

This is needed for the Landlock patch series. :)
---
kernel/bpf/syscall.c | 52 ++++++++++++++++++++++++++--------------------------
1 file changed, 26 insertions(+), 26 deletions(-)

diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index 6c772adabad2..c653ee0bd162 100644
--- 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)
--
2.13.3