MirBSD manpage: minherit(2)

MINHERIT(2)                BSD Programmer's Manual                 MINHERIT(2)

NAME

     minherit - control the inheritance of pages

SYNOPSIS

     #include <sys/mman.h>

     int
     minherit(void *addr, size_t len, int inherit);

DESCRIPTION

     The minherit() system call changes the specified pages to have the inher-
     itance characteristic inherit. A page's inheritance characteristic con-
     trols how it will be mapped in child processes as created by fork(2).

     The possible inheritance characteristics are:

           MAP_INHERIT_NONE   Pages are not mapped in the child process.
           MAP_INHERIT_COPY   Private copy of pages are mapped in the child
                              process.
           MAP_INHERIT_SHARE  Mapped pages are shared between the parent and
                              child processes.
           MAP_INHERIT_ZERO   New anonymous pages (initialized to all zero
                              bytes) are mapped in the child process.

     Not all implementations will guarantee that the inheritance characteris-
     tic can be set on a page basis; the granularity of changes may be as
     large as an entire region.

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 indicate the
     error.

ERRORS

     The minherit() system call will fail if:

     [EINVAL]      The virtual address range specified by the addr and len ar-
                   guments is not valid.

     [EINVAL]      The inherit argument is invalid.

SEE ALSO

     madvise(2), mincore(2), mprotect(2), msync(2), munmap(2)

HISTORY

     The minherit() function first appeared in OpenBSD 2.0. The
     MAP_INHERIT_ZERO flag first appeared in OpenBSD 5.6.

MirBSD #10-current              July 13, 2014                                1