memcheck/tests/big_blocks_freed_list.c

   1 #include <stdlib.h>
   2 /* To be run with --freelist-vol=1000000 --freelist-big-blocks=50000 */
   3 static void jumped(void)
   4 {
   5    ;
   6 }
   7 int main(int argc, char *argv[])
   8 {
   9    char *semi_big = NULL;
  10    char *big = NULL;
  11    char *small = NULL;
  12    char *other_small = NULL;
  13    int i;
  14    int j;
  15
  16    /* Verify that access via a dangling pointer to a big block bigger than
  17       the free list is found by memcheck (still on the free list). */
  18    semi_big = malloc (900000);
  19    big = malloc (1000015);
  20    free(semi_big);
  21    free(big);
  22    if (big[1000] > 0x0) jumped();
  23    if (semi_big[1000] > 0x0) jumped();
  24
  25    /* Then verify that dangling pointers for small blocks is not hampered
  26       by doing big alloc/free. */
  27    small = malloc (10000);
  28    free(small);
  29
  30    /* We should still have a nice error msg for the semi_big
  31       but not for the big block, which has been removed from the free list
  32       with the malloc of small above. */
  33    if (big[2000] > 0x0) jumped();
  34    if (semi_big[2000] > 0x0) jumped();
  35
  36    big = NULL;
  37
  38    {
  39       big = malloc (1000015);
  40       free(big);
  41       if (small[10] > 0x0) jumped();
  42
  43       /* Do not common up the below in a loop. We
  44          want a different error/stack trace for each of
  45          these. */
  46       if (big[10] > 0x0) jumped();
  47    }
  48
  49
  50    for (i = 0; i < 100; i++) {
  51       other_small = malloc(10000);
  52       for (j = 0; j < 10000; j++)
  53          other_small[j] = 0x1;
  54    }
  55    if (small[10] > 0x0) jumped();
  56    return 0;
  57 }