1.\" $NetBSD: access.9,v 1.1 1996/06/16 10:38:35 pk Exp $ 2.\" 3.\" Copyright (c) 1996 The NetBSD Foundation, Inc. 4.\" All rights reserved. 5.\" 6.\" This code is derived from software contributed to The NetBSD Foundation 7.\" by Paul Kranenburg. 8.\" 9.\" Redistribution and use in source and binary forms, with or without 10.\" modification, are permitted provided that the following conditions 11.\" are met: 12.\" 1. Redistributions of source code must retain the above copyright 13.\" notice, this list of conditions and the following disclaimer. 14.\" 2. Redistributions in binary form must reproduce the above copyright 15.\" notice, this list of conditions and the following disclaimer in the 16.\" documentation and/or other materials provided with the distribution. 17.\" 18.\" THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 19.\" ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 20.\" TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 21.\" PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE 22.\" LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 23.\" CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 24.\" SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 25.\" INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 26.\" CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 27.\" ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 28.\" POSSIBILITY OF SUCH DAMAGE. 29.\" 30.\" $FreeBSD$ 31.\" 32.Dd June 16, 1996 33.Dt KERNACC 9 34.Os 35.Sh NAME 36.Nm kernacc , 37.Nm useracc 38.Nd check memory regions for accessibility 39.Sh SYNOPSIS 40.In sys/param.h 41.In sys/proc.h 42.In vm/vm.h 43.In vm/vm_extern.h 44.Ft int 45.Fn kernacc "void *addr" "int len" "int rw" 46.Ft int 47.Fn useracc "void *addr" "int len" "int rw" 48.Sh DESCRIPTION 49The 50.Fn kernacc 51and 52.Fn useracc 53functions check whether operations of the type specified in 54.Fa rw 55are permitted in the range of virtual addresses given by 56.Fa addr 57and 58.Fa len . 59The possible values of 60.Fa rw 61are any bitwise combination of 62.Dv VM_PROT_READ , 63.Dv VM_PROT_WRITE 64and 65.Dv VM_PROT_EXECUTE . 66.Fn kernacc 67checks addresses in the kernel address space, while 68.Fn useracc 69considers 70.Fa addr 71to represent an user space address. 72The process context to use for this 73operation is taken from the global variable 74.Va curproc . 75.Sh RETURN VALUES 76Both functions return boolean true if the type of access specified 77by 78.Fa rw 79is permitted. 80Otherwise boolean false is returned. 81.Sh BUGS 82The process pointer should be passed in as an argument to 83.Fn useracc . 84