.\" Copyright (c) 1991, 1993 .\" The Regents of the University of California. All rights reserved. .\" .\" Redistribution and use in source and binary forms, with or without .\" modification, are permitted provided that the following conditions .\" are met: .\" 1. Redistributions of source code must retain the above copyright .\" notice, this list of conditions and the following disclaimer. .\" 2. Redistributions in binary form must reproduce the above copyright .\" notice, this list of conditions and the following disclaimer in the .\" documentation and/or other materials provided with the distribution. .\" 4. Neither the name of the University nor the names of its contributors .\" may be used to endorse or promote products derived from this software .\" without specific prior written permission. .\" .\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND .\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE .\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE .\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE .\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL .\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS .\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) .\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT .\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF .\" SUCH DAMAGE. .\" .\" @(#)munmap.2 8.3 (Berkeley) 5/27/94 .\" $FreeBSD$ .\" .Dd May 27, 1994 .Dt MUNMAP 2 .Os .Sh NAME .Nm munmap .Nd remove a mapping .Sh LIBRARY .Lb libc .Sh SYNOPSIS .In sys/mman.h .Ft int .Fn munmap "void *addr" "size_t len" .Sh DESCRIPTION The .Fn munmap system call deletes the mappings for the specified address range, and causes further references to addresses within the range to generate invalid memory references. .Sh RETURN VALUES .Rv -std munmap .Sh ERRORS The .Fn munmap system call will fail if: .Bl -tag -width Er .It Bq Er EINVAL The .Fa addr argument was not page aligned, the .Fa len argument was zero or negative, or some part of the region being unmapped is outside the valid address range for a process. .El .Sh "SEE ALSO" .Xr madvise 2 , .Xr mincore 2 , .Xr mmap 2 , .Xr mprotect 2 , .Xr msync 2 , .Xr getpagesize 3 .Sh HISTORY The .Fn munmap system call first appeared in .Bx 4.4 .