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#ifndef __LINUX_UIO_H
#define __LINUX_UIO_H
#include <linux/compiler.h>
#include <linux/types.h>
/*
* Berkeley style UIO structures - Alan Cox 1994.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*/
/* A word of warning: Our uio structure will clash with the C library one (which is now obsolete). Remove the C
library one from sys/uio.h if you have a very old library set */
struct iovec
{
void __user *iov_base; /* BSD uses caddr_t (1003.1g requires void *) */
__kernel_size_t iov_len; /* Must be size_t (1003.1g) */
};
#ifdef __KERNEL__
struct kvec {
void *iov_base; /* and that should *never* hold a userland pointer */
size_t iov_len;
};
#endif
/*
* UIO_MAXIOV shall be at least 16 1003.1g (5.4.1.1)
*/
#define UIO_FASTIOV 8
#define UIO_MAXIOV 1024
#if 0
#define UIO_MAXIOV 16 /* Maximum iovec's in one operation
16 matches BSD */
/* Beg pardon: BSD has 1024 --ANK */
#endif
/*
* Total number of bytes covered by an iovec.
*
* NOTE that it is not safe to use this function until all the iovec's
* segment lengths have been validated. Because the individual lengths can
* overflow a size_t when added together.
*/
static inline size_t iov_length(const struct iovec *iov, unsigned long nr_segs)
{
unsigned long seg;
size_t ret = 0;
for (seg = 0; seg < nr_segs; seg++)
ret += iov[seg].iov_len;
return ret;
}
unsigned long iov_shorten(struct iovec *iov, unsigned long nr_segs, size_t to);
#endif
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