useracc (9)

Leading comments

	$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.

 Redistribution and use in source and binary forms, with or without
 modification, are permitted provided that the following conditions
 are met:
 1. Redistributions of source code must retain the above copyright
    notice, this list of conditions and the following disclaime...

(The comments found at the beginning of the groff file "man9/useracc.9freebsd".)

NAME

kernacc useracc - check memory regions for accessibility

SYNOPSIS

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

DESCRIPTION

The Fn kernacc and Fn useracc functions check whether operations of the type specified in Fa rw are permitted in the range of virtual addresses given by Fa addr and Fa len . The possible values of Fa rw are any bitwise combination of VM_PROT_READ VM_PROT_WRITE and VM_PROT_EXECUTE Fn kernacc checks addresses in the kernel address space, while Fn useracc considers Fa addr to represent an user space address. The process context to use for this operation is taken from the global variable curproc

RETURN VALUES

Both functions return boolean true if the type of access specified by Fa rw is permitted. Otherwise boolean false is returned.

BUGS

The process pointer should be passed in as an argument to Fn useracc .