/* -*- linux-c -*-
 * 
 * Try to trigger DRAM disturbance errors, as described in
 *
 * https://www.ece.cmu.edu/~safari/pubs/kim-isca14.pdf
 *
 * Copyright 2014 Pavel Machek <pavel@ucw.cz>, GPLv2+.
 */

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

void disturb(char *where)
{
	unsigned int i;
	for (i=0; i<0x1000000; i++) {
		__asm__ __volatile__(
			"movl 0(%0), %%eax 		\n"	\
			"movl 64(%0), %%eax		\n"	\
			"clflush 0(%0)			\n"	\
			"clflush 64(%0)			\n"	\
			"mfence"
			:: "r" (where)
			: "eax"
			);
	}
}

int main(int argc, char *argv[])
{
	long size = 1*1024*1024;
	long i;
	unsigned char *mem;
	
	mem = malloc(size);
	memset(mem, 0xff, size);

	for (i=0; i<128; i+=4)
		disturb(mem+i);

	for (i=0; i<size; i++)
		if (mem[i] != 0xff)
			printf("At %lx, got %x\n", i, mem[i]);
}