.\"	$NetBSD: ufetch.9,v 1.1 2019/04/06 03:06:24 thorpej Exp $
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.\" by Jason R. Thorpe.
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.Dd March 18, 2019
.Dt UFETCH 9
.Os
.Sh NAME
.Nm ufetch ,
.Nm ufetch_8 ,
.Nm ufetch_16 ,
.Nm ufetch_32 ,
.Nm ufetch_64 ,
.Nm ufetch_char ,
.Nm ufetch_short ,
.Nm ufetch_int ,
.Nm ufetch_long ,
.Nm ufetch_ptr
.Nd fetch data from user-space
.Sh SYNOPSIS
.In sys/systm.h
.Ft int
.Fn ufetch_8 "const uint8_t *uaddr" "uint8_t *valp"
.Ft int
.Fn ufetch_16 "const uint16_t *uaddr" "uint16_t *valp"
.Ft int
.Fn ufetch_32 "const uint32_t *uaddr" "uint32_t *valp"
.Ft int
.Fn ufetch_64 "const uint64_t *uaddr" "uint64_t *valp"
.Ft int
.Fn ufetch_char "const unsigned char *uaddr" "unsigned char *valp"
.Ft int
.Fn ufetch_short "const unsigned short *uaddr" "unsigned short *valp"
.Ft int
.Fn ufetch_int "const unsigned int *uaddr" "unsigned int *valp"
.Ft int
.Fn ufetch_long "const unsigned long *uaddr" "unsigned long *valp"
.Ft int
.Fn ufetch_ptr "const void **uaddr" "void **valp"
.Sh DESCRIPTION
The
.Nm
functions provide a way to fetch the values of single memory cells from
user-space.
In each case, the value referenced by the user-space address
.Ar uaddr
is retrieved and stored at the kernel memory location referenced by
.Ar valp .
.Pp
The
.Nm ufetch_64
function is only available on systems employing the
.Sq LP64
memory model, which can be determined by testing for the presence of the
.Dv _LP64
C preprocessor macro.
.Sh RETURN VALUES
The
.Nm
functions return 0 on success and an error number on failure.
.Sh SEE ALSO
.Xr copy 9 ,
.Xr ustore 9