just another top chunk move

nope.c

#include <stdio.h>
#include <stdlib.h>

long buf[] = {0, 0, (long)buf, (long)buf};

int size = 200; // non-fastbin size

int main() {
    setvbuf(stdin, 0, 2, 0);
    setvbuf(stdout, 0, 2, 0);
    setvbuf(stderr, 0, 2, 0);
    long *a = malloc(size);
    a[-1] &= ~1;
    a[-2] = (char *)(a - 2) - (char *)buf;
    free(a);
    printf("top is %p! and buf is %p.\n", malloc(1), buf);
}