Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
tjh.dev
kernel
os
linux
1#include <linux/uaccess.h>
2#include <linux/export.h>
3#include <linux/uio.h>
4
5/*
6 * Copy iovec to kernel. Returns -EFAULT on error.
7 *
8 * Note: this modifies the original iovec.
9 */
10
11int memcpy_fromiovec(unsigned char *kdata, struct iovec *iov, int len)
12{
13 while (len > 0) {
14 if (iov->iov_len) {
15 int copy = min_t(unsigned int, len, iov->iov_len);
16 if (copy_from_user(kdata, iov->iov_base, copy))
17 return -EFAULT;
18 len -= copy;
19 kdata += copy;
20 iov->iov_base += copy;
21 iov->iov_len -= copy;
22 }
23 iov++;
24 }
25
26 return 0;
27}
28EXPORT_SYMBOL(memcpy_fromiovec);
29
30/*
31 * Copy kernel to iovec. Returns -EFAULT on error.
32 *
33 * Note: this modifies the original iovec.
34 */
35
36int memcpy_toiovec(struct iovec *iov, unsigned char *kdata, int len)
37{
38 while (len > 0) {
39 if (iov->iov_len) {
40 int copy = min_t(unsigned int, iov->iov_len, len);
41 if (copy_to_user(iov->iov_base, kdata, copy))
42 return -EFAULT;
43 kdata += copy;
44 len -= copy;
45 iov->iov_len -= copy;
46 iov->iov_base += copy;
47 }
48 iov++;
49 }
50
51 return 0;
52}
53EXPORT_SYMBOL(memcpy_toiovec);
54
55/*
56 * Copy kernel to iovec. Returns -EFAULT on error.
57 */
58
59int memcpy_toiovecend(const struct iovec *iov, unsigned char *kdata,
60 int offset, int len)
61{
62 int copy;
63 for (; len > 0; ++iov) {
64 /* Skip over the finished iovecs */
65 if (unlikely(offset >= iov->iov_len)) {
66 offset -= iov->iov_len;
67 continue;
68 }
69 copy = min_t(unsigned int, iov->iov_len - offset, len);
70 if (copy_to_user(iov->iov_base + offset, kdata, copy))
71 return -EFAULT;
72 offset = 0;
73 kdata += copy;
74 len -= copy;
75 }
76
77 return 0;
78}
79EXPORT_SYMBOL(memcpy_toiovecend);
80
81/*
82 * Copy iovec to kernel. Returns -EFAULT on error.
83 */
84
85int memcpy_fromiovecend(unsigned char *kdata, const struct iovec *iov,
86 int offset, int len)
87{
88 /* No data? Done! */
89 if (len == 0)
90 return 0;
91
92 /* Skip over the finished iovecs */
93 while (offset >= iov->iov_len) {
94 offset -= iov->iov_len;
95 iov++;
96 }
97
98 while (len > 0) {
99 u8 __user *base = iov->iov_base + offset;
100 int copy = min_t(unsigned int, len, iov->iov_len - offset);
101
102 offset = 0;
103 if (copy_from_user(kdata, base, copy))
104 return -EFAULT;
105 len -= copy;
106 kdata += copy;
107 iov++;
108 }
109
110 return 0;
111}
112EXPORT_SYMBOL(memcpy_fromiovecend);