NetBSD/lib/libc/sys/minherit.2

.\"	$NetBSD: minherit.2,v 1.9 2001/09/16 01:39:01 wiz Exp $
.\"
.\" Copyright (c) 1991, 1993
.\"	The Regents of the University of California.  All rights reserved.
.\"
.\" 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 disclaimer.
.\" 2. Redistributions in binary form must reproduce the above copyright
.\"    notice, this list of conditions and the following disclaimer in the
.\"    documentation and/or other materials provided with the distribution.
.\" 3. All advertising materials mentioning features or use of this software
.\"    must display the following acknowledgement:
.\"	This product includes software developed by the University of
.\"	California, Berkeley and its contributors.
.\" 4. Neither the name of the University nor the names of its contributors
.\"    may be used to endorse or promote products derived from this software
.\"    without specific prior written permission.
.\"
.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
.\" ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
.\" SUCH DAMAGE.
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.\"	@(#)minherit.2	8.1 (Berkeley) 6/9/93
.\"
.Dd June 9, 1993
.Dt MINHERIT 2
.Os
.Sh NAME
.Nm minherit
.Nd control the inheritance of pages
.Sh LIBRARY
.Lb libc
.Sh SYNOPSIS
.Fd #include <sys/mman.h>
.Ft int
.Fn minherit "void *addr" "size_t len" "int inherit"
.Sh DESCRIPTION
The
.Fn minherit
system call
changes the specified range of virtual addresses to have the specified
fork-time inheritance characteristic
.Fa inherit ,
which can be set to
.Dv MAP_INHERIT_NONE ,
.Dv MAP_INHERIT_COPY ,
or
.Dv MAP_INHERIT_SHARE .
Also possible is
.Dv MAP_INHERIT_DEFAULT ,
which defaults to
.Dv MAP_INHERIT_COPY .
Not all implementations will guarantee that the inheritance characteristic
can be set on a page basis;
the granularity of changes may be as large as an entire region.
.Pp
Normally, the entire address space is marked
.Dv MAP_INHERIT_COPY ;
when the process calls
.Fn fork ,
the child receives a (virtual) copy of the entire address space.
Pages or regions marked
.Dv MAP_INHERIT_SHARE
are shared between the address spaces, while pages or regions marked
.Dv MAP_INHERIT_NONE
will be unmapped in the child.
.Sh BUGS
If the a particular port does not support page-granularity
inheritance, there's no way to figure out how large a region is
actually affected by
.Fn minherit .
.Sh SEE ALSO
.Xr fork 2 ,
.Xr madvise 2 ,
.Xr mincore 2 ,
.Xr mprotect 2 ,
.Xr msync 2 ,
.Xr munmap 2
.Sh HISTORY
The
.Fn minherit
function first appeared in
.Bx Open .
Boring whitespace fixes. 2001-09-16 05:38:59 +04:00			`.\" $NetBSD: minherit.2,v 1.9 2001/09/16 01:39:01 wiz Exp $`
import minherit from OpenBSD 1997-09-08 22:42:43 +04:00			`.\"`
			`.\" Copyright (c) 1991, 1993`
			`.\" The Regents of the University of California. All rights reserved.`
			`.\"`
			`.\" 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 disclaimer.`
			`.\" 2. Redistributions in binary form must reproduce the above copyright`
			`.\" notice, this list of conditions and the following disclaimer in the`
			`.\" documentation and/or other materials provided with the distribution.`
			`.\" 3. All advertising materials mentioning features or use of this software`
			`.\" must display the following acknowledgement:`
			`.\" This product includes software developed by the University of`
			`.\" California, Berkeley and its contributors.`
			`.\" 4. Neither the name of the University nor the names of its contributors`
			`.\" may be used to endorse or promote products derived from this software`
			`.\" without specific prior written permission.`
			`.\"`
			.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
			`.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE`
			`.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE`
			`.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE`
			`.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL`
			`.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS`
			`.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)`
			`.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT`
			`.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY`
			`.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF`
			`.\" SUCH DAMAGE.`
			`.\"`
			`.\" @(#)minherit.2 8.1 (Berkeley) 6/9/93`
			`.\"`
			`.Dd June 9, 1993`
			`.Dt MINHERIT 2`
			`.Os`
			`.Sh NAME`
			`.Nm minherit`
			`.Nd control the inheritance of pages`
Add a LIBRARY section to system call manual pages. While it's clear that the libraries contain stubs only (with minor exceptions a la pipe(2)), the purpose of this section is to provide linkage information. 1999-12-03 00:42:35 +03:00			`.Sh LIBRARY`
			`.Lb libc`
import minherit from OpenBSD 1997-09-08 22:42:43 +04:00			`.Sh SYNOPSIS`
			`.Fd #include <sys/mman.h>`
			`.Ft int`
caddr_t -> void * PR/4269: Chris Demetriou: Add MS_* to msync() 1997-10-17 03:21:47 +04:00			`.Fn minherit "void *addr" "size_t len" "int inherit"`
import minherit from OpenBSD 1997-09-08 22:42:43 +04:00			`.Sh DESCRIPTION`
			`The`
Boring whitespace fixes. 2001-09-16 05:38:59 +04:00			`.Fn minherit`
import minherit from OpenBSD 1997-09-08 22:42:43 +04:00			`system call`
Explain what this function actually does 2000-06-25 20:28:41 +04:00			`changes the specified range of virtual addresses to have the specified`
			`fork-time inheritance characteristic`
punctuation fix (. -> ,) 2000-06-26 02:37:30 +04:00			`.Fa inherit ,`
Boring whitespace fixes. 2001-09-16 05:38:59 +04:00			`which can be set to`
Rename VM_INHERIT_* to MAP_INHERIT_* and move them to sys/sys/mman.h as discussed on tech-kern. Retire sys/uvm/uvm_inherit.h, update man page for minherit(2). 2000-08-01 04:53:07 +04:00			`.Dv MAP_INHERIT_NONE ,`
Whitespace fix, noted by John Hawkinson. 2000-08-05 00:03:07 +04:00			`.Dv MAP_INHERIT_COPY ,`
Rename VM_INHERIT_* to MAP_INHERIT_* and move them to sys/sys/mman.h as discussed on tech-kern. Retire sys/uvm/uvm_inherit.h, update man page for minherit(2). 2000-08-01 04:53:07 +04:00			`or`
			`.Dv MAP_INHERIT_SHARE .`
			`Also possible is`
			`.Dv MAP_INHERIT_DEFAULT ,`
			`which defaults to`
			`.Dv MAP_INHERIT_COPY .`
import minherit from OpenBSD 1997-09-08 22:42:43 +04:00			`Not all implementations will guarantee that the inheritance characteristic`
			`can be set on a page basis;`
			`the granularity of changes may be as large as an entire region.`
Explain what this function actually does 2000-06-25 20:28:41 +04:00			`.Pp`
Boring whitespace fixes. 2001-09-16 05:38:59 +04:00			`Normally, the entire address space is marked`
Rename VM_INHERIT_* to MAP_INHERIT_* and move them to sys/sys/mman.h as discussed on tech-kern. Retire sys/uvm/uvm_inherit.h, update man page for minherit(2). 2000-08-01 04:53:07 +04:00			`.Dv MAP_INHERIT_COPY ;`
			`when the process calls`
Explain what this function actually does 2000-06-25 20:28:41 +04:00			`.Fn fork ,`
			`the child receives a (virtual) copy of the entire address space.`
Boring whitespace fixes. 2001-09-16 05:38:59 +04:00			`Pages or regions marked`
Rename VM_INHERIT_* to MAP_INHERIT_* and move them to sys/sys/mman.h as discussed on tech-kern. Retire sys/uvm/uvm_inherit.h, update man page for minherit(2). 2000-08-01 04:53:07 +04:00			`.Dv MAP_INHERIT_SHARE`
			`are shared between the address spaces, while pages or regions marked`
			`.Dv MAP_INHERIT_NONE`
			`will be unmapped in the child.`
Explain what this function actually does 2000-06-25 20:28:41 +04:00			`.Sh BUGS`
			`If the a particular port does not support page-granularity`
			`inheritance, there's no way to figure out how large a region is`
Boring whitespace fixes. 2001-09-16 05:38:59 +04:00			`actually affected by`
Explain what this function actually does 2000-06-25 20:28:41 +04:00			`.Fn minherit .`
import minherit from OpenBSD 1997-09-08 22:42:43 +04:00			`.Sh SEE ALSO`
Explain what this function actually does 2000-06-25 20:28:41 +04:00			`.Xr fork 2 ,`
Boring whitespace fixes. 2001-09-16 05:38:59 +04:00			`.Xr madvise 2 ,`
			`.Xr mincore 2 ,`
			`.Xr mprotect 2 ,`
import minherit from OpenBSD 1997-09-08 22:42:43 +04:00			`.Xr msync 2 ,`
			`.Xr munmap 2`
			`.Sh HISTORY`
			`The`
			`.Fn minherit`
			`function first appeared in`
			`.Bx Open .`