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.\" 30.Dd June 22, 2017 31.Dt MUNMAP 2 32.Os 33.Sh NAME 34.Nm munmap 35.Nd remove a mapping 36.Sh LIBRARY 37.Lb libc 38.Sh SYNOPSIS 39.In sys/mman.h 40.Ft int 41.Fn munmap "void *addr" "size_t len" 42.Sh DESCRIPTION 43The 44.Fn munmap 45system call 46deletes the mappings and guards for the specified address range, 47and causes further references to addresses within the range 48to generate invalid memory references. 49.Sh RETURN VALUES 50.Rv -std munmap 51.Sh ERRORS 52The 53.Fn munmap 54system call 55will fail if: 56.Bl -tag -width Er 57.It Bq Er EINVAL 58The 59.Fa addr 60argument was not page aligned, the 61.Fa len 62argument was zero or negative, or 63some part of the region being unmapped is outside the 64valid address range for a process. 65.El 66.Sh "SEE ALSO" 67.Xr madvise 2 , 68.Xr mincore 2 , 69.Xr mmap 2 , 70.Xr mprotect 2 , 71.Xr msync 2 , 72.Xr getpagesize 3 73.Sh HISTORY 74The 75.Fn munmap 76system call first appeared in 77.Bx 4.4 . 78