munmap(2)                                                         munmap(2)

NAME
     munmap - terminate mapping of memory pages

SYNOPSIS
     #include <sys/mman.h>

     int munmap(void *addr, sizet len);

DESCRIPTION
     The munmap() function removes the mappings for pages in the range
     [addr, addr + len) and in the process rounds up the len argument to
     the next multiple of the page length, as returned by sysconf(). The
     resulting behavior is indeterminate if addr is not the address of a
     mapping created by a previous mmap() call. When munmap() has been
     called successfully and before any remaining unmapped pages are
     mapped, further references to these pages results in a SIGBUS or
     SIGSEGV signal being output to the process.

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

ERRORS
     The following error code descriptions are function-specific. You will
     find a general description in introprm2(2) or in errno(5).

     Under the following conditions, the function munmap() fails and sets
     errno to:

     EINVAL    if addr is not a multiple of the page size as returned by
               sysconf().

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

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

RESULT
     Upon successful completion, the function munmap() returns a value of
     0; otherwise, it returns a value of -1 and sets errno to indicate an
     error.

SEE ALSO
     mmap(2), sysconf(3C), mman(5).













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