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.\"	@(#)munmap.2	8.3 (Berkeley) 5/27/94
.\"
.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
Upon successful completion,
.Nm munmap
returns zero.
Otherwise, a value of \-1 is returned and
.Va errno
is set to indicate the error.
.Sh ERRORS
.Fn munmap
will fail if:
.Bl -tag -width Er
.It Bq Er EINVAL
The
.Fa addr
parameter was not page aligned, 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 mlock 2 ,
.Xr mmap 2 ,
.Xr mprotect 2 ,
.Xr msync 2 ,
.Xr getpagesize 3
.Sh STANDARDS
The
.Fn munmap
function conforms to
.St -p1003.1b-93 .
.Sh HISTORY
The
.Fn munmap
function first appeared in
.Bx 4.4 .