vm-crash3.c

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

#if defined(__mips__)
#define INSN_TYPE unsigned int
#define INVAL_INSN  0x0000003f
#else
#error "Please fix this"
#endif

void write_to_code(void);
void read_data(void);
void write_data(void);

void
write_to_code(void)
{
  extern int func_150();
  /* picking a code page that should no longer be in the TLB */
        INSN_TYPE *x = (INSN_TYPE *) func_150;
        *x = INVAL_INSN;

        printf("IF THIS PRINTS THE TEST FAILED\n");
}

extern void     call_all(void);

#define PAGE_SIZE (4096)
#define PAGES     (128)
#define SIZE      (PAGE_SIZE * PAGES / sizeof(int))
#define NUM_REFS  (2)

unsigned int array[SIZE];

void
write_data(void)
{
        unsigned int refs = 0;
        unsigned int i = 0;

        for (refs = 0; refs < NUM_REFS-1; refs++) {
                for (i=0; i<SIZE; i+= PAGE_SIZE) {
                        array[i] = i;
                }
        }
}

void
read_data(void)
{
        unsigned int i = 0;

        for (i=0; i<SIZE; i+= PAGE_SIZE) {
                if (array[i] != i) {
                        printf("FAILED array[%d] = %u != %d\n", i, array[i], i);
                        exit(1);
                }
        }
}


int
main()
{
        unsigned int i = 0;

        for (i=0; i<5; i++) {
          call_all();
          write_data();
          call_all();
          read_data();
        }

        /* This won't hopefully return becasue it crashes */
        write_to_code();
        exit(0);
}