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 len argument was zero, or some part of the region being unmapped is outside the valid address range for a process.

SEE ALSO

madvise(2), mincore(2), mmap(2), mprotect(2), msync(2), getpagesize(3)

STANDARDS

The munmap() system call conforms to IEEE Std 1003.1-2024 (“POSIX.1”). Portable programs should ensure that addr is a multiple of the page size as returned by sysconf(3).

HISTORY

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