COPY(9) BSD Kernel Developer's Manual COPY(9)NAME
copy, copyin, copyinstr, copyout, copystr — kernel copy functions
SYNOPSIS
#include <sys/types.h>
#include <sys/systm.h>
int
copyin(const void *uaddr, void *kaddr, size_t len);
int
copyinstr(const void *uaddr, void *kaddr, size_t len, size_t *done);
int
copyout(const void *kaddr, void *uaddr, size_t len);
int
copystr(const void *kfaddr, void *kdaddr, 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 copy routines provide the following functionality:
copyin() Copies len bytes of data from the user-space address uaddr
to the kernel-space address kaddr.
copyinstr() 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.
copyout() Copies len bytes of data from the kernel-space address
kaddr to the user-space address uaddr.
copystr() 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.
RETURN VALUES
The copy functions return 0 on success or the following error on failure:
[EFAULT] If a bad address is encountered. When this error is
returned, the contents of the destination buffer (
*kaddr for copyin(), copyinstr(), and copystr();
*uaddr for copyout()) are undefined. For copyinstr()
and copystr(), the contents of the *done parameter are
also undefined on a return of EFAULT.
In addition to EFAULT, copystr() and copyinstr() on failure will return:
[ENAMETOLONG] When the string is longer than len bytes. On this
error return, the destination buffer is not null-ter‐
minated, but the *done parameter is maintained.
SEE ALSOfetch(9), store(9)BSD October 2, 2008 BSD