NAME
copy, copyin,
copyin_nofault, copyout,
copyout_nofault, copystr,
copyinstr —
kernel copy functions
SYNOPSIS
#include
<sys/types.h>
#include <sys/systm.h>
int
copyin(const
void *uaddr, void
*kaddr, size_t
len);
int
copyin_nofault(const
void *uaddr, void
*kaddr, size_t
len);
int
copyout(const
void *kaddr, void
*uaddr, size_t
len);
int
copyout_nofault(const
void *kaddr, void
*uaddr, size_t
len);
int
copystr(const
void *kfaddr, void
*kdaddr, size_t
len, size_t
*done);
int
copyinstr(const
void *uaddr, void
*kaddr, size_t len,
size_t *done);
DESCRIPTION
Thecopy functions are designed to copy contiguous data
from one address to another. All but
copystr()
copy data from user-space to kernel-space or vice-versa.
The
copyin() and
copyin_nofault() functions copy
len bytes of data from the user-space address
uaddr to the kernel-space address
kaddr.
The
copyout()
and
copyout_nofault()
functions copy len bytes of data from the kernel-space
address kaddr to the user-space address
uaddr.
The
copyin_nofault()
and
copyout_nofault()
functions require that the kernel-space and user-space data be accessible
without incurring a page fault. The source and destination addresses must be
physically mapped for read and write access, respectively, and neither the
source nor destination addresses may be pageable.
The
copystr()
function copies a NUL-terminated string, at most len
bytes long, from kernel-space address kfaddr to
kernel-space address kdaddr. The number of bytes
actually copied, including the terminating NUL, is returned in
*done (if done is
non-NULL).
The
copyinstr()
function copies a NUL-terminated string, at most len
bytes long, from user-space address uaddr to
kernel-space address kaddr. The number of bytes
actually copied, including the terminating NUL, is returned in
*done (if done is
non-NULL).
RETURN VALUES
The copy functions return 0 on success or
EFAULT if a bad address is encountered. In addition,
the copyin_nofault() and
copyout_nofault() functions return
EFAULT if a page fault occurs, and the
copystr() and copyinstr()
functions return ENAMETOOLONG if the string is
longer than len bytes.