fubyte(9) [freebsd man page]

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

NAME

     fetch, fubyte, fuswintr, fuword, fuword16, fuword32, fuword64, fueword, fueword32, fueword64 -- fetch data from user-space

SYNOPSIS

     #include <sys/types.h>
     #include <sys/systm.h>

     int
     fubyte(volatile const void *base);

     long
     fuword(volatile const void *base);

     int
     fuword16(volatile const void *base);

     int32_t
     fuword32(volatile const void *base);

     int64_t
     fuword64(volatile const void *base);

     long
     fueword(volatile const void *base, long *val);

     int32_t
     fueword32(volatile const void *base, int32_t *val);

     int64_t
     fueword64(volatile const void *base, int64_t *val);

     #include <sys/resourcevar.h>

     int
     fuswintr(void *base);

DESCRIPTION

     The fetch functions are designed to copy small amounts of data from user-space of the current process.  If read is successful, it is per-
     formed atomically.  The data read must be naturally aligned.

     The fetch routines provide the following functionality:

     fubyte()	  Fetches a byte of data from the user-space address base.  The byte read is zero-extended into the results variable.

     fuword()	  Fetches a word of data (long) from the user-space address base.

     fuword16()   Fetches 16 bits of data from the user-space address base.  The half-word read is zero-extended into the results variable.

     fuword32()   Fetches 32 bits of data from the user-space address base.

     fuword64()   Fetches 64 bits of data from the user-space address base.

     fuswintr()   Fetches a short word of data from the user-space address base.  This function is safe to call during an interrupt context.

     fueword()	  Fetches a word of data (long) from the user-space address base and stores the result in the variable pointed by val.

     fueword32()  Fetches 32 bits of data from the user-space address base and stores the result in the variable pointed by val.

     fueword64()  Fetches 64 bits of data from the user-space address base and stores the result in the variable pointed by val.

     The callers of fuword(), fuword32() and fuword64() functions cannot distinguish between -1 read from userspace and function failure.

RETURN VALUES

     The fubyte(), fuword(), fuword16(), fuword32(), fuword64(), and fuswintr() functions return the data fetched or -1 on failure.  The
     fueword(), fueword32() and fueword64() functions return 0 on success and -1 on failure.

SEE ALSO

     copy(9), store(9)

BSD
								 October 29, 2014							       BSD

Check Out this Related Man Page

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

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 num-
                   ber 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.

SEE ALSO

     fetch(9), store(9)

BSD                                                               January 7, 1996                                                              BSD

Linux and UNIX Man Pages

fubyte(9) [freebsd man page]

Check Out this Related Man Page