aboutsummaryrefslogtreecommitdiff
path: root/lib/iovec.c
blob: 454baa88bf27dd18aa896be8930652f75e3ddad9 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
#include <linux/uaccess.h>
#include <linux/export.h>
#include <linux/uio.h>

/*
 *	Copy iovec to kernel. Returns -EFAULT on error.
 *
 *	Note: this modifies the original iovec.
 */

int memcpy_fromiovec(unsigned char *kdata, struct iovec *iov, int len)
{
	while (len > 0) {
		if (iov->iov_len) {
			int copy = min_t(unsigned int, len, iov->iov_len);
			if (copy_from_user(kdata, iov->iov_base, copy))
				return -EFAULT;
			len -= copy;
			kdata += copy;
			iov->iov_base += copy;
			iov->iov_len -= copy;
		}
		iov++;
	}

	return 0;
}
EXPORT_SYMBOL(memcpy_fromiovec);

/*
 *	Copy kernel to iovec. Returns -EFAULT on error.
 *
 *	Note: this modifies the original iovec.
 */

int memcpy_toiovec(struct iovec *iov, unsigned char *kdata, int len)
{
	while (len > 0) {
		if (iov->iov_len) {
			int copy = min_t(unsigned int, iov->iov_len, len);
			if (copy_to_user(iov->iov_base, kdata, copy))
				return -EFAULT;
			kdata += copy;
			len -= copy;
			iov->iov_len -= copy;
			iov->iov_base += copy;
		}
		iov++;
	}

	return 0;
}
EXPORT_SYMBOL(memcpy_toiovec);