FETCH(9) | Kernel Developer's Manual | FETCH(9) |
fetch
, fubyte
,
fuibyte
, fusword
,
fuswintr
, fuword
,
fuiword
—
#include <sys/types.h>
#include <sys/systm.h>
int
fubyte
(const
void *base);
int
fusword
(const
void *base);
int
fuswintr
(const
void *base);
long
fuword
(const
void *base);
fetch
functions are designed to copy small amounts
of data from user-space.
The fetch
routines provide the following
functionality:
fubyte
()fusword
()fuswintr
()fuword
()fetch
functions return the data fetched or -1 on
failure. Note that these functions all do "unsigned" access, and
therefore will never sign extend byte or short values. This prevents ambiguity
with the error return value for all functions except
fuword
().
fuword
() has no way to unambiguously signal
an error, because the data it reads might legitimately be the same as the -1
used to indicate an error. The other functions do not have this problem
because the unsigned values returned by those can never match the -1 error
return value.
January 7, 1996 | NetBSD 8.99 |