1.\" $OpenBSD: munmap.2,v 1.9 1999/06/29 14:10:10 aaron 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. All advertising materials mentioning features or use of this software 16.\" must display the following acknowledgement: 17.\" This product includes software developed by the University of 18.\" California, Berkeley and its contributors. 19.\" 4. Neither the name of the University nor the names of its contributors 20.\" may be used to endorse or promote products derived from this software 21.\" without specific prior written permission. 22.\" 23.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 24.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 25.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 26.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 27.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 28.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 29.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 30.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 31.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 32.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 33.\" SUCH DAMAGE. 34.\" 35.\" @(#)munmap.2 8.2 (Berkeley) 4/15/94 36.\" 37.Dd April 15, 1994 38.Dt MUNMAP 2 39.Os 40.Sh NAME 41.Nm munmap 42.Nd remove a mapping 43.Sh SYNOPSIS 44.Fd #include <sys/types.h> 45.Fd #include <sys/mman.h> 46.Ft int 47.Fn munmap "void *addr" "size_t len" 48.Sh DESCRIPTION 49The 50.Fn munmap 51system call 52deletes the mappings for the specified address range, 53and causes further references to addresses within the range 54to generate invalid memory references. 55.Sh RETURN VALUES 56Upon successful completion, 57.Nm munmap 58returns zero. 59Otherwise, a value of \-1 is returned and 60.Va errno 61is set to indicate the error. 62.Sh ERRORS 63.Fn munmap 64will fail if: 65.Bl -tag -width Er 66.It Bq Er EINVAL 67The 68.Fa addr 69parameter was not page aligned, the 70.Fa len 71parameter was negative, or 72some part of the region being unmapped is not part of the currently 73valid address space. 74.El 75.Sh SEE ALSO 76.Xr madvise 2 , 77.Xr mincore 2 , 78.Xr mprotect 2 , 79.Xr msync 2 , 80.Xr getpagesize 3 81.Sh HISTORY 82The 83.Fn munmap 84function first appeared in 85.Bx 4.4 . 86