.\"	%NetBSD: access.9,v 1.1 1996/06/16 10:38:35 pk Exp %
.\"
.\" Copyright (c) 1996 The NetBSD Foundation, Inc.
.\" All rights reserved.
.\"
.\" This code is derived from software contributed to The NetBSD Foundation
.\" by Paul Kranenburg.
.\"
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.\" 3. All advertising materials mentioning features or use of this software
.\"    must display the following acknowledgement:
.\"        This product includes software developed by the NetBSD
.\"        Foundation, Inc. and its contributors.
.\" 4. Neither the name of The NetBSD Foundation nor the names of its
.\"    contributors may be used to endorse or promote products derived
.\"    from this software without specific prior written permission.
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.\" %FreeBSD: src/share/man/man9/kernacc.9,v 1.13 2003/01/21 11:34:57 alfred Exp %
.\"
.\" $FreeBSD$
.Dd June 16, 1996
.Dt KERNACC 9
.Os
.Sh 名称
.Nm kernacc ,
.Nm useracc
.Nd メモリ領域がアクセス可能か否かの調査
.Sh 書式
.In sys/param.h
.In sys/proc.h
.In vm/vm.h
.In vm/vm_extern.h
.Ft int
.Fn kernacc "void *addr" "int len" "int rw"
.Ft int
.Fn useracc "void *addr" "int len" "int rw"
.Sh 解説
.Fn kernacc
および
.Fn useracc
関数は、
.Fa addr
および
.Fa len
によって与えられる仮想アドレス範囲で、
.Fa rw
で指定された操作のタイプが許可されるかどうかを調査します。
.Fa rw
の指定可能な値は、
.Dv VM_PROT_READ ,
.Dv VM_PROT_WRITE
および
.Dv VM_PROT_EXECUTE
の論理合成値です。
.Fn kernacc
はカーネルアドレス空間の中のアドレスを調べ、一方
.Fn useracc
は
.Fa addr
をユーザ空間のアドレス表現とみなします。
この操作に使用されるプロセスコンテキストは大域変数
.Va curproc
から得られます。
.Sh 戻り値
どちらの関数も、
.Fa rw
によって指定されるタイプのアクセスが許可されている場合には、
ブール値 true を返します。
そうでない場合には、ブール値 false が返されます。
.Sh バグ
.Fn useracc
への引数として、プロセスへのポインタが渡されるべきです。