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/* $OpenBSD: minherit.c,v 1.1 2002/01/31 15:53:12 art Exp $ */
/*
* Written by Artur Grabowski <art@openbsd.org> Public Domain.
*/
#include <sys/types.h>
#include <sys/wait.h>
#include <sys/mman.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <err.h>
#define MAGIC "inherited"
int
main()
{
void *map1, *map2;
int page_size;
int status;
page_size = getpagesize();
if ((map1 = mmap(NULL, page_size, PROT_READ|PROT_WRITE, MAP_ANON,
-1, 0)) == MAP_FAILED)
err(1, "mmap");
if ((map2 = mmap(NULL, page_size, PROT_READ|PROT_WRITE, MAP_ANON,
-1, 0)) == MAP_FAILED)
err(1, "mmap");
memset(map1, 0, sizeof(MAGIC));
memcpy(map2, MAGIC, sizeof(MAGIC));
if (minherit(map1, page_size, MAP_INHERIT_SHARE) != 0)
err(1, "minherit");
if (minherit(map2, page_size, MAP_INHERIT_NONE) != 0)
err(1, "minherit");
switch(fork()) {
case -1:
err(1, "fork");
case 0:
memcpy(map1, MAGIC, sizeof(MAGIC));
/* map2 is not mapped and should give us error on munmap */
if (munmap(map2, page_size) == 0)
_exit(1);
_exit(0);
}
if (wait(&status) < 0)
err(1, "wait");
if (!WIFEXITED(status))
err(1, "child error");
if (memcmp(map1, MAGIC, sizeof(MAGIC)) != 0)
return 1;
return WEXITSTATUS(status) != 0;
}
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