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.\" 3. All advertising materials mentioning features or use of this software 18.\" must display the following acknowledgement: 19.\" This product includes software developed by the NetBSD 20.\" Foundation, Inc. and its contributors. 21.\" 4. Neither the name of The NetBSD Foundation nor the names of its 22.\" contributors may be used to endorse or promote products derived 23.\" from this software without specific prior written permission. 24.\" 25.\" THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 26.\" ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 27.\" TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 28.\" PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE 29.\" LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 30.\" CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 31.\" SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 32.\" INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 33.\" CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 34.\" ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 35.\" POSSIBILITY OF SUCH DAMAGE. 36.\" 37.Dd June 16, 1996 38.Dt KERNACC 9 39.Os FreeBSD 40.Sh NAME 41.Nm kernacc , 42.Nm useracc 43.Nd check memory regions for accessibility 44.Sh SYNOPSIS 45.Fd #include <sys/types.h> 46.Fd #include <vm/vm.h> 47.Fd #include <vm/vm_extern.h> 48.Ft int 49.Fn kernacc "caddr_t addr" "int len" "int rw" 50.Ft int 51.Fn useracc "caddr_t addr" "int len" "int rw" 52.Sh DESCRIPTION 53The 54.Fn kernacc 55and 56.Fn useracc 57functions check whether operations of the type specified in 58.Fa rw 59are permitted in the range of virtual addresses given by 60.Fa addr 61and 62.Fa len . 63The possible values of 64.Fa rw 65are 66.Dv B_READ 67and 68.Dv B_WRITE . 69.Fn kernacc 70checks addresses in the kernel address space, while 71.Fn useracc 72considers 73.Fa addr 74to represent an user space address. The process context to use for this 75operation is taken from the global variable 76.Va curproc . 77.Pp 78.Sh RETURN VALUES 79Both functions return 1 if the type of access specified by 80.Fa rw 81is permitted. Otherwise 0 is returned. 82.Pp 83.Sh BUGS 84The process pointer should be passed in as an argument. 85