blob: c55ce243cc0985c450786e4cb63f8ed3c8e5c53b [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * Berkeley style UIO structures - Alan Cox 1994.
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public License
6 * as published by the Free Software Foundation; either version
7 * 2 of the License, or (at your option) any later version.
8 */
David Howells607ca462012-10-13 10:46:48 +01009#ifndef __LINUX_UIO_H
10#define __LINUX_UIO_H
Linus Torvalds1da177e2005-04-16 15:20:36 -070011
David Howells607ca462012-10-13 10:46:48 +010012#include <uapi/linux/uio.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070013
Jiri Slaby812ed032009-07-29 15:04:19 -070014
15struct kvec {
16 void *iov_base; /* and that should *never* hold a userland pointer */
17 size_t iov_len;
18};
19
Linus Torvalds1da177e2005-04-16 15:20:36 -070020/*
21 * Total number of bytes covered by an iovec.
22 *
23 * NOTE that it is not safe to use this function until all the iovec's
24 * segment lengths have been validated. Because the individual lengths can
25 * overflow a size_t when added together.
26 */
27static inline size_t iov_length(const struct iovec *iov, unsigned long nr_segs)
28{
29 unsigned long seg;
30 size_t ret = 0;
31
32 for (seg = 0; seg < nr_segs; seg++)
33 ret += iov[seg].iov_len;
34 return ret;
35}
36
37unsigned long iov_shorten(struct iovec *iov, unsigned long nr_segs, size_t to);
Rusty Russelld2f83e92013-05-17 09:05:21 +093038
39int memcpy_fromiovec(unsigned char *kdata, struct iovec *iov, int len);
40int memcpy_toiovec(struct iovec *iov, unsigned char *kdata, int len);
Jiri Slaby812ed032009-07-29 15:04:19 -070041#endif