/* * Copyright 2017, Anshuman Khandual, IBM Corp. * Licensed under GPLv2. * * Works on architectures which support 128TB virtual * address range and beyond. */#include <stdio.h>#include <stdlib.h>#include <string.h>#include <unistd.h>#include <errno.h>#include <sys/mman.h>#include <sys/time.h> /* * Maximum address range mapped with a single mmap() * call is little bit more than 16GB. Hence 16GB is * chosen as the single chunk size for address space * mapping. */#define MAP_CHUNK_SIZE   17179869184UL /* 16GB */ /* * Address space till 128TB is mapped without any hint * and is enabled by default. Address space beyond 128TB * till 512TB is obtained by passing hint address as the * first argument into mmap() system call. * * The process heap address space is divided into two * different areas one below 128TB and one above 128TB * till it reaches 512TB. One with size 128TB and the * other being 384TB. * * On Arm64 the address space is 256TB and no high mappings * are supported so far. */ #define NR_CHUNKS_128TB   8192UL /* Number of 16GB chunks for 128TB */#define NR_CHUNKS_256TB   (NR_CHUNKS_128TB * 2UL)#define NR_CHUNKS_384TB   (NR_CHUNKS_128TB * 3UL) #define ADDR_MARK_128TB  (1UL << 47) /* First address beyond 128TB */#define ADDR_MARK_256TB  (1UL << 48) /* First address beyond 256TB */ #ifdef __aarch64__#define HIGH_ADDR_MARK  ADDR_MARK_256TB#define HIGH_ADDR_SHIFT 49#define NR_CHUNKS_LOW   NR_CHUNKS_256TB#define NR_CHUNKS_HIGH  0#else#define HIGH_ADDR_MARK  ADDR_MARK_128TB#define HIGH_ADDR_SHIFT 48#define NR_CHUNKS_LOW   NR_CHUNKS_128TB#define NR_CHUNKS_HIGH  NR_CHUNKS_384TB#endif static char *hind_addr(void){	int bits = HIGH_ADDR_SHIFT + rand() % (63 - HIGH_ADDR_SHIFT); 	return (char *) (1UL << bits);} static int validate_addr(char *ptr, int high_addr){	unsigned long addr = (unsigned long) ptr; 	if (high_addr) {		if (addr < HIGH_ADDR_MARK) {			printf("Bad address %lx\n", addr);			return 1;		}		return 0;	} 	if (addr > HIGH_ADDR_MARK) {		printf("Bad address %lx\n", addr);		return 1;	}	return 0;} static int validate_lower_address_hint(void){	char *ptr; 	ptr = mmap((void *) (1UL << 45), MAP_CHUNK_SIZE, PROT_READ |			PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0); 	if (ptr == MAP_FAILED)		return 0; 	return 1;} int main(int argc, char *argv[]){	char *ptr[NR_CHUNKS_LOW];	char *hptr[NR_CHUNKS_HIGH];	char *hint;	unsigned long i, lchunks, hchunks; 	for (i = 0; i < NR_CHUNKS_LOW; i++) {		ptr[i] = mmap(NULL, MAP_CHUNK_SIZE, PROT_READ | PROT_WRITE,					MAP_PRIVATE | MAP_ANONYMOUS, -1, 0); 		if (ptr[i] == MAP_FAILED) {			if (validate_lower_address_hint())				return 1;			break;		} 		if (validate_addr(ptr[i], 0))			return 1;	}	lchunks = i; 	for (i = 0; i < NR_CHUNKS_HIGH; i++) {		hint = hind_addr();		hptr[i] = mmap(hint, MAP_CHUNK_SIZE, PROT_READ | PROT_WRITE,					MAP_PRIVATE | MAP_ANONYMOUS, -1, 0); 		if (hptr[i] == MAP_FAILED)			break; 		if (validate_addr(hptr[i], 1))			return 1;	}	hchunks = i; 	for (i = 0; i < lchunks; i++)		munmap(ptr[i], MAP_CHUNK_SIZE); 	for (i = 0; i < hchunks; i++)		munmap(hptr[i], MAP_CHUNK_SIZE); 	return 0;}