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git.proxmox.com Git - mirror_ubuntu-zesty-kernel.git/blob - include/linux/uio.h
4 #include <linux/compiler.h>
5 #include <linux/types.h>
8 * Berkeley style UIO structures - Alan Cox 1994.
10 * This program is free software; you can redistribute it and/or
11 * modify it under the terms of the GNU General Public License
12 * as published by the Free Software Foundation; either version
13 * 2 of the License, or (at your option) any later version.
17 /* A word of warning: Our uio structure will clash with the C library one (which is now obsolete). Remove the C
18 library one from sys/uio.h if you have a very old library set */
22 void __user
*iov_base
; /* BSD uses caddr_t (1003.1g requires void *) */
23 __kernel_size_t iov_len
; /* Must be size_t (1003.1g) */
29 void *iov_base
; /* and that should *never* hold a userland pointer */
36 * UIO_MAXIOV shall be at least 16 1003.1g (5.4.1.1)
40 #define UIO_MAXIOV 1024
42 #define UIO_MAXIOV 16 /* Maximum iovec's in one operation
44 /* Beg pardon: BSD has 1024 --ANK */
48 * Total number of bytes covered by an iovec.
50 * NOTE that it is not safe to use this function until all the iovec's
51 * segment lengths have been validated. Because the individual lengths can
52 * overflow a size_t when added together.
54 static inline size_t iov_length(const struct iovec
*iov
, unsigned long nr_segs
)
59 for (seg
= 0; seg
< nr_segs
; seg
++)
60 ret
+= iov
[seg
].iov_len
;
64 unsigned long iov_shorten(struct iovec
*iov
, unsigned long nr_segs
, size_t to
);