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/*
* 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;
}
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