---
name: "munmap"
section: "2freebsd"
platform: "linux"
package: "freebsd-manpages"
version: "12.2-2"
release: "Debian 13 (Trixie)"
platforms: ["linux"]
url: "https://new.carta.tech/munmap/2freebsd"
---

# munmap(2freebsd)

remove a mapping

## NAME

**munmap** – remove a mapping

## LIBRARY

Standard C Library (libc, -lc)

## SYNOPSIS

**#include \<sys/mman.h\>**

*int*\

**munmap**(*void \*addr*, *size\_t len*);

## DESCRIPTION

The **munmap**() system call deletes the mappings and guards for the specified address range, and causes further references to addresses within the range to generate invalid memory references.

## RETURN VALUES

The **munmap()** function returns the value 0 if successful; otherwise the value -1 is returned and the global variable errno is set to indicate the error.

## ERRORS

The **munmap**() system call will fail if:

- \[EINVAL\]

  The *addr* argument was not page aligned, the *len* argument was zero or negative, or some part of the region being unmapped is outside the valid address range for a process.

## SEE ALSO

[madvise(2)](/madvise/2.md), [mincore(2)](/mincore/2.md), [mmap(2)](/mmap/2.md), [mprotect(2)](/mprotect/2.md), [msync(2)](/msync/2.md), [getpagesize(3)](/getpagesize/3.md)

## HISTORY

The **munmap**() system call first appeared in 4.4BSD.