NAME
copy, copyin, copyout, 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
copyout(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 copy routines provide the following functionality:
- copyin()
-
Copies len bytes of data from the user-space address uaddr to the kernel-space address kaddr.
- 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 (if done is non-NULL).
- 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 (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 copystr(), and copyinstr() functions return ENAMETOOLONG if the string is longer than len bytes.