1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 *
4 * Copyright (C) IBM Corporation, 2010
5 *
6 * Author: Anton Blanchard <anton@au.ibm.com>
7 */
8 #include <linux/export.h>
9 #include <linux/compiler.h>
10 #include <linux/types.h>
11 #include <asm/checksum.h>
12 #include <linux/uaccess.h>
13
csum_and_copy_from_user(const void __user * src,void * dst,int len)14 __wsum csum_and_copy_from_user(const void __user *src, void *dst,
15 int len)
16 {
17 __wsum csum;
18
19 if (unlikely(!user_read_access_begin(src, len)))
20 return 0;
21
22 csum = csum_partial_copy_generic((void __force *)src, dst, len);
23
24 user_read_access_end();
25 return csum;
26 }
27 EXPORT_SYMBOL(csum_and_copy_from_user);
28
csum_and_copy_to_user(const void * src,void __user * dst,int len)29 __wsum csum_and_copy_to_user(const void *src, void __user *dst, int len)
30 {
31 __wsum csum;
32
33 if (unlikely(!user_write_access_begin(dst, len)))
34 return 0;
35
36 csum = csum_partial_copy_generic(src, (void __force *)dst, len);
37
38 user_write_access_end();
39 return csum;
40 }
41 EXPORT_SYMBOL(csum_and_copy_to_user);
42