MINHERIT(2) BSD System Calls Manual MINHERIT(2)
NAME
minherit -- control the inheritance of pages
LIBRARY
Standard C Library (libc, -lc)
SYNOPSIS
#include <sys/mman.h>
int
minherit(void *addr, size_t len, int inherit);
DESCRIPTION
The minherit() system call changes the specified range of virtual addresses to have the specified fork-time inheritance characteristic
inherit, which can be set to MAP_INHERIT_NONE, MAP_INHERIT_COPY, or MAP_INHERIT_SHARE. Also possible is MAP_INHERIT_DEFAULT, which defaults
to MAP_INHERIT_COPY. Not all implementations will guarantee that the inheritance characteristic can be set on a page basis; the granularity
of changes may be as large as an entire region.
Normally, the entire address space is marked MAP_INHERIT_COPY; when the process calls fork(), the child receives a (virtual) copy of the
entire address space. Pages or regions marked MAP_INHERIT_SHARE are shared between the address spaces, while pages or regions marked
MAP_INHERIT_NONE will be unmapped in the child.
RETURN VALUES
The minherit() function returns the value 0 if successful; otherwise the value -1 is returned and the global variable errno is set to indi-
cate the error.
ERRORS
minherit() will fail if:
[EINVAL] An invalid region or invalid parameters were specified.
SEE ALSO
fork(2), madvise(2), mincore(2), mprotect(2), msync(2), munmap(2)
HISTORY
The minherit() function first appeared in OpenBSD.
BUGS
If a particular port does not support page-granularity inheritance, there's no way to figure out how large a region is actually affected by
minherit().
BSD
October 7, 2006 BSD