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.Dd June 22, 2017 29.Dt MUNMAP 2 30.Os 31.Sh NAME 32.Nm munmap 33.Nd remove a mapping 34.Sh LIBRARY 35.Lb libc 36.Sh SYNOPSIS 37.In sys/mman.h 38.Ft int 39.Fn munmap "void *addr" "size_t len" 40.Sh DESCRIPTION 41The 42.Fn munmap 43system call 44deletes the mappings and guards for the specified address range, 45and causes further references to addresses within the range 46to generate invalid memory references. 47.Sh RETURN VALUES 48.Rv -std munmap 49.Sh ERRORS 50The 51.Fn munmap 52system call 53will fail if: 54.Bl -tag -width Er 55.It Bq Er EINVAL 56The 57.Fa addr 58argument was not page aligned, the 59.Fa len 60argument was zero or negative, or 61some part of the region being unmapped is outside the 62valid address range for a process. 63.El 64.Sh "SEE ALSO" 65.Xr madvise 2 , 66.Xr mincore 2 , 67.Xr mmap 2 , 68.Xr mprotect 2 , 69.Xr msync 2 , 70.Xr getpagesize 3 71.Sh HISTORY 72The 73.Fn munmap 74system call first appeared in 75.Bx 4.4 . 76