linux-stable/include/linux/uio.h

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/*
* 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.
*/
#ifndef __LINUX_UIO_H
#define __LINUX_UIO_H
#include <uapi/linux/uio.h>
struct kvec {
void *iov_base; /* and that should *never* hold a userland pointer */
size_t iov_len;
};
/*
* 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);
int memcpy_fromiovec(unsigned char *kdata, struct iovec *iov, int len);
int memcpy_toiovec(struct iovec *iov, unsigned char *kdata, int len);
#endif