#define TRIES 3

/* ugly. copied from 'bits/mman.h' */
#define PROT_READ	0x1
#define PROT_WRITE	0x2
#define MAP_PRIVATE	0x02
#define MAP_FIXED	0x10
#define MAP_ANONYMOUS	0x20

void *mmap(void *addr, size_t length, int prot, int flags, int fd, off_t offset);

long try0(long);
long try1(long);
long try2(long);

/* try these adresses until one is free */
long *tries[TRIES] = {
	(long *)0x00100000,
	(long *)0x01000000,
	(long *)0xA0000000
};

int   t    = 0;
long *addr = NULL;

for (t = 0; t < TRIES; t++) {
	addr = mmap(tries[t], 4096, PROT_READ | PROT_WRITE,
	            MAP_PRIVATE | MAP_ANONYMOUS | MAP_FIXED, -1, 0);

	if (tries[t] == addr)
		break;
}

if ((void *)-1 == addr) {
	puts("unable to map memory");
	RET(1); /* keep the statistic clean */
}

addr[2] = 1337;

printf("try %d\n", t);

switch (t) {
case 0:	RET(try0(0xcafebabe) == 1337);
case 1:	RET(try1(0xcafebabe) == 1337);
case 2:	RET(try2(0xcafebabe) == 1337);
}