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.Dd June 16, 1996 31.Dt KERNACC 9 32.Os 33.Sh NAME 34.Nm kernacc , 35.Nm useracc 36.Nd check memory regions for accessibility 37.Sh SYNOPSIS 38.In sys/param.h 39.In sys/proc.h 40.In vm/vm.h 41.In vm/vm_extern.h 42.Ft int 43.Fn kernacc "void *addr" "int len" "int rw" 44.Ft int 45.Fn useracc "void *addr" "int len" "int rw" 46.Sh DESCRIPTION 47The 48.Fn kernacc 49and 50.Fn useracc 51functions check whether operations of the type specified in 52.Fa rw 53are permitted in the range of virtual addresses given by 54.Fa addr 55and 56.Fa len . 57The possible values of 58.Fa rw 59are any bitwise combination of 60.Dv VM_PROT_READ , 61.Dv VM_PROT_WRITE 62and 63.Dv VM_PROT_EXECUTE . 64.Fn kernacc 65checks addresses in the kernel address space, while 66.Fn useracc 67considers 68.Fa addr 69to represent an user space address. 70The process context to use for this 71operation is taken from the global variable 72.Va curproc . 73.Sh RETURN VALUES 74Both functions return boolean true if the type of access specified 75by 76.Fa rw 77is permitted. 78Otherwise boolean false is returned. 79.Sh BUGS 80The process pointer should be passed in as an argument to 81.Fn useracc . 82