LXR linux/lib/iovec.c

   1#include <linux/uaccess.h>
   2#include <linux/export.h>
   3#include <linux/uio.h>
   4
   5/*
   6 *      Copy iovec to kernel. Returns -EFAULT on error.
   7 *
   8 *      Note: this modifies the original iovec.
   9 */
  10
  11int memcpy_fromiovec(unsigned char *kdata, struct iovec *iov, int len)
  12{
  13        while (len > 0) {
  14                if (iov->iov_len) {
  15                        int copy = min_t(unsigned int, len, iov->iov_len);
  16                        if (copy_from_user(kdata, iov->iov_base, copy))
  17                                return -EFAULT;
  18                        len -= copy;
  19                        kdata += copy;
  20                        iov->iov_base += copy;
  21                        iov->iov_len -= copy;
  22                }
  23                iov++;
  24        }
  25
  26        return 0;
  27}
  28EXPORT_SYMBOL(memcpy_fromiovec);
  29
  30/*
  31 *      Copy kernel to iovec. Returns -EFAULT on error.
  32 *
  33 *      Note: this modifies the original iovec.
  34 */
  35
  36int memcpy_toiovec(struct iovec *iov, unsigned char *kdata, int len)
  37{
  38        while (len > 0) {
  39                if (iov->iov_len) {
  40                        int copy = min_t(unsigned int, iov->iov_len, len);
  41                        if (copy_to_user(iov->iov_base, kdata, copy))
  42                                return -EFAULT;
  43                        kdata += copy;
  44                        len -= copy;
  45                        iov->iov_len -= copy;
  46                        iov->iov_base += copy;
  47                }
  48                iov++;
  49        }
  50
  51        return 0;
  52}
  53EXPORT_SYMBOL(memcpy_toiovec);
  54