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¶
The
copy
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.
SEE ALSO¶
fetch(9),
store(9)