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}
31EXPORT_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}
48EXPORT_SYMBOL(csum_and_copy_to_user);
49