copyout

COPY(9)                  BSD Kernel Developer's Manual                 COPY(9)

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.  All but copystr() return EFAULT
     if a bad address is encountered.  The copyin_nofault() and
     copyout_nofault() functions return EFAULT if a page fault occurs.  The
     copystr() and copyinstr() functions return ENAMETOOLONG if the string is
     longer than len bytes.

SEE ALSO
     fetch(9), store(9)

BSD                              June 15, 2017                             BSD