munmap(2)

NAME

munmap − unmap pages of memory

SYNOPSIS

#include <sys/mman.h>

int munmap(void addr, size_t len);

DESCRIPTION

The munmap() function removes the mappings for pages in the range [addr, addr + len), rounding the len argument up to the next multiple of the page size as returned by sysconf(3C). If addr is not the address of a mapping established by a prior call to mmap(2), the behavior is undefined. After a successful call to munmap() and before any subsequent mapping of the unmapped pages, further references to these pages will result in the delivery of a SIGBUS or SIGSEGV signal to the process.

The mmap(2) function often performs an implicit munmap().

RETURN VALUES

Upon successful completion, munmap() returns 0; otherwise, it returns −1 and sets errno to indicate an error.

ERRORS

The munmap() function will fail if:

EINVAL The addr argument is not a multiple of the page size as returned by sysconf(3C).

EINVAL Addresses in the range [addr, addr + len) are outside the valid range for the address space of a process.

EINVAL The len argument has a value less than or equal to 0.

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