src/splat/splat-random.c

   1 #include <sys/zfs_context.h>
   2 #include <sys/splat-ctl.h>
   3
   4 #define KZT_SUBSYSTEM_KRNG              0x0300
   5 #define KZT_KRNG_NAME                   "krng"
   6 #define KZT_KRNG_DESC                   "Kernel Random Number Generator Tests"
   7
   8 #define KZT_KRNG_TEST1_ID               0x0301
   9 #define KZT_KRNG_TEST1_NAME             "freq"
  10 #define KZT_KRNG_TEST1_DESC             "Frequency Test"
  11
  12 #define KRNG_NUM_BITS                   1048576
  13 #define KRNG_NUM_BYTES                  (KRNG_NUM_BITS >> 3)
  14 #define KRNG_NUM_BITS_DIV2              (KRNG_NUM_BITS >> 1)
  15 #define KRNG_ERROR_RANGE                2097
  16
  17 /* Random Number Generator Tests
  18    There can be meny more tests on quality of the
  19    random number generator.  For now we are only
  20    testing the frequency of particular bits.
  21    We could also test consecutive sequences,
  22    randomness within a particular block, etc.
  23    but is probably not necessary for our purposes */
  24
  25 static int
  26 kzt_krng_test1(struct file *file, void *arg)
  27 {
  28         uint8_t *buf;
  29         int i, j, diff, num = 0, rc = 0;
  30
  31         buf = kmalloc(sizeof(*buf) * KRNG_NUM_BYTES, GFP_KERNEL);
  32         if (buf == NULL) {
  33                 rc = -ENOMEM;
  34                 goto out;
  35         }
  36
  37         memset(buf, 0, sizeof(*buf) * KRNG_NUM_BYTES);
  38
  39         /* Always succeeds */
  40         random_get_pseudo_bytes(buf, sizeof(uint8_t) * KRNG_NUM_BYTES);
  41
  42         for (i = 0; i < KRNG_NUM_BYTES; i++) {
  43                 uint8_t tmp = buf[i];
  44                 for (j = 0; j < 8; j++) {
  45                         uint8_t tmp2 = ((tmp >> j) & 0x01);
  46                         if (tmp2 == 1) {
  47                                 num++;
  48                         }
  49                 }
  50         }
  51
  52         kfree(buf);
  53
  54         diff = KRNG_NUM_BITS_DIV2 - num;
  55         if (diff < 0)
  56                 diff *= -1;
  57
  58         kzt_print(file, "Test 1 Number of ones: %d\n", num);
  59         kzt_print(file, "Test 1 Difference from expected: %d Allowed: %d\n",
  60                   diff, KRNG_ERROR_RANGE);
  61
  62         if (diff > KRNG_ERROR_RANGE)
  63                 rc = -ERANGE;
  64 out:
  65         return rc;
  66 }
  67
  68 kzt_subsystem_t *
  69 kzt_krng_init(void)
  70 {
  71         kzt_subsystem_t *sub;
  72
  73         sub = kmalloc(sizeof(*sub), GFP_KERNEL);
  74         if (sub == NULL)
  75                 return NULL;
  76
  77         memset(sub, 0, sizeof(*sub));
  78         strncpy(sub->desc.name, KZT_KRNG_NAME, KZT_NAME_SIZE);
  79         strncpy(sub->desc.desc, KZT_KRNG_DESC, KZT_DESC_SIZE);
  80         INIT_LIST_HEAD(&sub->subsystem_list);
  81         INIT_LIST_HEAD(&sub->test_list);
  82         spin_lock_init(&sub->test_lock);
  83         sub->desc.id = KZT_SUBSYSTEM_KRNG;
  84
  85         KZT_TEST_INIT(sub, KZT_KRNG_TEST1_NAME, KZT_KRNG_TEST1_DESC,
  86                       KZT_KRNG_TEST1_ID, kzt_krng_test1);
  87
  88         return sub;
  89 }
  90
  91 void
  92 kzt_krng_fini(kzt_subsystem_t *sub)
  93 {
  94         ASSERT(sub);
  95
  96         KZT_TEST_FINI(sub, KZT_KRNG_TEST1_ID);
  97
  98         kfree(sub);
  99 }
 100
 101 int
 102 kzt_krng_id(void) {
 103         return KZT_SUBSYSTEM_KRNG;
 104 }