1.\" $OpenBSD: munmap.2,v 1.10 2003/06/02 20:18:39 millert Exp $ 2.\" $NetBSD: munmap.2,v 1.5 1995/02/27 12:35:03 cgd Exp $ 3.\" 4.\" Copyright (c) 1991, 1993 5.\" The Regents of the University of California. All rights reserved. 6.\" 7.\" Redistribution and use in source and binary forms, with or without 8.\" modification, are permitted provided that the following conditions 9.\" are met: 10.\" 1. Redistributions of source code must retain the above copyright 11.\" notice, this list of conditions and the following disclaimer. 12.\" 2. Redistributions in binary form must reproduce the above copyright 13.\" notice, this list of conditions and the following disclaimer in the 14.\" documentation and/or other materials provided with the distribution. 15.\" 3. Neither the name of the University nor the names of its contributors 16.\" may be used to endorse or promote products derived from this software 17.\" without specific prior written permission. 18.\" 19.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 20.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 23.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29.\" SUCH DAMAGE. 30.\" 31.\" @(#)munmap.2 8.2 (Berkeley) 4/15/94 32.\" 33.Dd April 15, 1994 34.Dt MUNMAP 2 35.Os 36.Sh NAME 37.Nm munmap 38.Nd remove a mapping 39.Sh SYNOPSIS 40.Fd #include <sys/types.h> 41.Fd #include <sys/mman.h> 42.Ft int 43.Fn munmap "void *addr" "size_t len" 44.Sh DESCRIPTION 45The 46.Fn munmap 47system call 48deletes the mappings for the specified address range, 49and causes further references to addresses within the range 50to generate invalid memory references. 51.Sh RETURN VALUES 52Upon successful completion, 53.Nm munmap 54returns zero. 55Otherwise, a value of \-1 is returned and 56.Va errno 57is set to indicate the error. 58.Sh ERRORS 59.Fn munmap 60will fail if: 61.Bl -tag -width Er 62.It Bq Er EINVAL 63The 64.Fa addr 65parameter was not page aligned, the 66.Fa len 67parameter was negative, or 68some part of the region being unmapped is not part of the currently 69valid address space. 70.El 71.Sh SEE ALSO 72.Xr madvise 2 , 73.Xr mincore 2 , 74.Xr mprotect 2 , 75.Xr msync 2 , 76.Xr getpagesize 3 77.Sh HISTORY 78The 79.Fn munmap 80function first appeared in 81.Bx 4.4 . 82