1.\" Copyright (c) 1991, 1993 2.\" The Regents of the University of California. All rights reserved. 3.\" 4.\" Redistribution and use in source and binary forms, with or without 5.\" modification, are permitted provided that the following conditions 6.\" are met: 7.\" 1. Redistributions of source code must retain the above copyright 8.\" notice, this list of conditions and the following disclaimer. 9.\" 2. Redistributions in binary form must reproduce the above copyright 10.\" notice, this list of conditions and the following disclaimer in the 11.\" documentation and/or other materials provided with the distribution. 12.\" 3. Neither the name of the University nor the names of its contributors 13.\" may be used to endorse or promote products derived from this software 14.\" without specific prior written permission. 15.\" 16.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 17.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 20.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26.\" SUCH DAMAGE. 27.\" 28.\" @(#)munmap.2 8.3 (Berkeley) 5/27/94 29.\" $FreeBSD$ 30.\" 31.Dd June 22, 2017 32.Dt MUNMAP 2 33.Os 34.Sh NAME 35.Nm munmap 36.Nd remove a mapping 37.Sh LIBRARY 38.Lb libc 39.Sh SYNOPSIS 40.In sys/mman.h 41.Ft int 42.Fn munmap "void *addr" "size_t len" 43.Sh DESCRIPTION 44The 45.Fn munmap 46system call 47deletes the mappings and guards for the specified address range, 48and causes further references to addresses within the range 49to generate invalid memory references. 50.Sh RETURN VALUES 51.Rv -std munmap 52.Sh ERRORS 53The 54.Fn munmap 55system call 56will fail if: 57.Bl -tag -width Er 58.It Bq Er EINVAL 59The 60.Fa addr 61argument was not page aligned, the 62.Fa len 63argument was zero or negative, or 64some part of the region being unmapped is outside the 65valid address range for a process. 66.El 67.Sh "SEE ALSO" 68.Xr madvise 2 , 69.Xr mincore 2 , 70.Xr mmap 2 , 71.Xr mprotect 2 , 72.Xr msync 2 , 73.Xr getpagesize 3 74.Sh HISTORY 75The 76.Fn munmap 77system call first appeared in 78.Bx 4.4 . 79