xref: /freebsd/share/man/man9/vm_map_submap.9 (revision d37ea99837e6ad50837fd9fe1771ddf1c3ba6002)
1.\"
2.\" Copyright (c) 2003 Bruce M Simpson <bms@spc.org>
3.\" All rights reserved.
4.\"
5.\" Redistribution and use in source and binary forms, with or without
6.\" modification, are permitted provided that the following conditions
7.\" are met:
8.\" 1. Redistributions of source code must retain the above copyright
9.\"    notice, this list of conditions and the following disclaimer.
10.\" 2. Redistributions in binary form must reproduce the above copyright
11.\"    notice, this list of conditions and the following disclaimer in the
12.\"    documentation and/or other materials provided with the distribution.
13.\"
14.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17.\" ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24.\" SUCH DAMAGE.
25.\"
26.\" $FreeBSD$
27.\"
28.Dd July 19, 2003
29.Dt vm_map_submap 9
30.Sh NAME
31.Nm vm_map_submap
32.Nd create a subordinate map
33.Sh SYNOPSIS
34.In sys/param.h
35.In vm/vm.h
36.In vm/vm_map.h
37.Ft int
38.Fn vm_map_submap "vm_map_t map" "vm_offset_t start" "vm_offset_t end" "vm_map_t submap"
39.Sh DESCRIPTION
40The
41.Fn vm_map_submap
42function marks the range bounded by
43.Fa start
44and
45.Fa end
46within the map
47.Fa map
48as being handled by a subordinate map
49.Fa sub_map .
50.Pp
51It is generally called by the kernel memory allocator.
52.Sh IMPLEMENTATION NOTES
53This function is for internal use only.
54.Pp
55Both maps must exist.
56The range must have been created with
57.Xr vm_map_find 9
58previously.
59.Pp
60No other operations may have been performed on this range
61before calling this function.
62Only the
63.Fn vm_fault
64operation may be performed within this range after calling
65this function.
66.Pp
67To remove a submapping, one must first remove the range from
68the parent
69.Fa map ,
70and then destroy the
71.Fa sub_map .
72This procedure is not recommended.
73.Sh RETURN VALUES
74The
75.Fn vm_map_submap
76function returns
77.Dv KERN_SUCCESS
78if successful.
79.Pp
80Otherwise, it returns
81.Dv KERN_INVALID_ARGUMENT
82if the caller requested copy-on-write flags,
83or if the range specified for the sub-map was out of range for the parent map,
84or if a NULL backing object was specified.
85.Sh SEE ALSO
86.Xr vm_map 9 ,
87.Xr vm_map_find 9
88.Sh AUTHORS
89This man page was written by
90.An Bruce M Simpson Aq bms@spc.org .
91