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#include <linux/uaccess.h>
#include <linux/export.h>
#include <linux/fs.h>
#include <linux/mm.h>
#include <linux/uio.h>
/*
* Copy iovec to kernel. Returns -EFAULT on error.
*
* Note: this modifies the original iovec.
*/
int memcpy_fromiovec(unsigned char *kdata, struct iovec *iov, int len)
{
while (len > 0) {
if (iov->iov_len) {
int copy = min_t(unsigned int, len, iov->iov_len);
if (copy_from_user(kdata, iov->iov_base, copy))
return -EFAULT;
len -= copy;
kdata += copy;
iov->iov_base += copy;
iov->iov_len -= copy;
}
iov++;
}
return 0;
}
EXPORT_SYMBOL(memcpy_fromiovec);
/*
* Copy kernel to iovec. Returns -EFAULT on error.
*
* Note: this modifies the original iovec.
*/
int memcpy_toiovec(struct iovec *iov, unsigned char *kdata, int len)
{
while (len > 0) {
if (iov->iov_len) {
int copy = min_t(unsigned int, iov->iov_len, len);
if (copy_to_user(iov->iov_base, kdata, copy))
return -EFAULT;
kdata += copy;
len -= copy;
iov->iov_len -= copy;
iov->iov_base += copy;
}
iov++;
}
return 0;
}
EXPORT_SYMBOL(memcpy_toiovec);
int iov_count_pages(const struct iov_iter *iter, unsigned align)
{
struct iov_iter i = *iter;
int nr_pages = 0;
while (iov_iter_count(&i)) {
unsigned long uaddr = (unsigned long) i.iov->iov_base +
i.iov_offset;
unsigned long len = i.iov->iov_len - i.iov_offset;
if ((uaddr & align) || (len & align))
return -EINVAL;
/*
* Overflow, abort
*/
if (uaddr + len < uaddr)
return -EINVAL;
nr_pages += DIV_ROUND_UP(len + offset_in_page(uaddr),
PAGE_SIZE);
iov_iter_advance(&i, len);
}
return nr_pages;
}
EXPORT_SYMBOL(iov_count_pages);
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