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 
14 __wsum csum_and_copy_from_user(const void __user *src, void *dst,
15 			       int len)
16 {
17 	__wsum csum;
18 
19 	might_sleep();
20 
21 	if (unlikely(!access_ok(src, len)))
22 		return 0;
23 
24 	allow_read_from_user(src, len);
25 
26 	csum = csum_partial_copy_generic((void __force *)src, dst, len);
27 
28 	prevent_read_from_user(src, len);
29 	return csum;
30 }
31 EXPORT_SYMBOL(csum_and_copy_from_user);
32 
33 __wsum csum_and_copy_to_user(const void *src, void __user *dst, int len)
34 {
35 	__wsum csum;
36 
37 	might_sleep();
38 	if (unlikely(!access_ok(dst, len)))
39 		return 0;
40 
41 	allow_write_to_user(dst, len);
42 
43 	csum = csum_partial_copy_generic(src, (void __force *)dst, len);
44 
45 	prevent_write_to_user(dst, len);
46 	return csum;
47 }
48 EXPORT_SYMBOL(csum_and_copy_to_user);
49