DragonFly On-Line Manual Pages


COPY(9) 	      DragonFly 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 des- tination 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) DragonFly 4.1 July 9, 2011 DragonFly 4.1