/* Reproduce a GNU malloc bug.  */

#include <malloc.h>

#include <stdio.h>

#include <string.h>

#define size_t unsigned int

/* Defined as global variables to avoid warnings about unused variables.  */

char *dummy0;

char *dummy1;

char *fill_info_table1;

int

main (int argc, char *argv[])

{

  char *over_top;

  size_t over_top_size = 0x3000;

  char *over_top_dup;

  size_t over_top_dup_size = 0x7000;

  char *x;

  size_t i;

  /* Here's what memory is supposed to look like (hex):

        size  contents

        3000  original_info_table, later fill_info_table1

      3fa000  dummy0

      3fa000  dummy1

        6000  info_table_2

        3000  over_top

   */

  /* mem: original_info_table */

  dummy0 = malloc (0x3fa000);

  /* mem: original_info_table, dummy0 */

  dummy1 = malloc (0x3fa000);

  /* mem: free, dummy0, dummy1, info_table_2 */

  fill_info_table1 = malloc (0x3000);

  /* mem: fill_info_table1, dummy0, dummy1, info_table_2 */

  x = malloc (0x1000);

  free (x);

  /* mem: fill_info_table1, dummy0, dummy1, info_table_2, freexx */

  /* This is what loses; info_table_2 and freexx get combined unbeknownst

     to mmalloc, and mmalloc puts over_top in a section of memory which

     is on the free list as part of another block (where info_table_2 had

     been).  */

  over_top = malloc (over_top_size);

  over_top_dup = malloc (over_top_dup_size);

  memset (over_top, 0, over_top_size);

  memset (over_top_dup, 1, over_top_dup_size);

  for (i = 0; i < over_top_size; ++i)

    if (over_top[i] != 0)

      {

        printf ("FAIL: malloc expands info table\n");

        return 0;

      }

  for (i = 0; i < over_top_dup_size; ++i)

    if (over_top_dup[i] != 1)

      {

        printf ("FAIL: malloc expands info table\n");

        return 0;

      }

  printf ("PASS: malloc expands info table\n");

  return 0;

}