valloc.c

#include <string.h>
#include <stdio.h>
#include <errno.h>

#include <sys/mman.h>

int main()
{
#if 0
	const size_t addr = 0x00000100f0000000;
	const size_t sz = 1024 * 1024 * 1024;
	printf("hint: 0x%lx, size: %ld\n", addr, sz);
	void *p = mmap( (void *)addr, // addr
			sz, // size
			PROT_READ | PROT_WRITE, //
			MAP_ANONYMOUS | MAP_PRIVATE, 
			-1, // fd
			0 // fseek
	);
	printf("auto: %p: %s\n", p, strerror(errno));
	munmap(p, sz);

	p = mmap( (void *)addr, // addr
			sz, // size
			PROT_READ | PROT_WRITE, //
			MAP_ANONYMOUS | MAP_FIXED, 
			-1, // fd
			0 // fseek
	);
	printf("fix : %p: %s\n", p, strerror(errno));
	munmap(p, sz);
	return 0;
#endif
	void *p =
	mmap( (void *) 0x80c0000000, 1048576, PROT_READ | PROT_WRITE, MAP_ANONYMOUS | MAP_PRIVATE, -1, 0);
	printf("auto: %p: %s\n", p, strerror(errno));
	p =
	mmap( (void *) 0x80c0000000, 1048576, PROT_READ | PROT_WRITE, MAP_ANONYMOUS | MAP_PRIVATE, -1, 0);
	printf("auto: %p: %s\n", p, strerror(errno));
	p =
	mmap( (void *) 0x80c0100000, 1048576, PROT_READ | PROT_WRITE, MAP_ANONYMOUS | MAP_PRIVATE, -1, 0);
	printf("auto: %p: %s\n", p, strerror(errno));

}