module/splat/splat-random.c

   1 /*
   2  *  This file is part of the SPL: Solaris Porting Layer.
   3  *
   4  *  Copyright (c) 2008 Lawrence Livermore National Security, LLC.
   5  *  Produced at Lawrence Livermore National Laboratory
   6  *  Written by:
   7  *          Brian Behlendorf <behlendorf1@llnl.gov>,
   8  *          Herb Wartens <wartens2@llnl.gov>,
   9  *          Jim Garlick <garlick@llnl.gov>
  10  *  UCRL-CODE-235197
  11  *
  12  *  This is free software; you can redistribute it and/or modify it
  13  *  under the terms of the GNU General Public License as published by
  14  *  the Free Software Foundation; either version 2 of the License, or
  15  *  (at your option) any later version.
  16  *
  17  *  This is distributed in the hope that it will be useful, but WITHOUT
  18  *  ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  19  *  FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  20  *  for more details.
  21  *
  22  *  You should have received a copy of the GNU General Public License along
  23  *  with this program; if not, write to the Free Software Foundation, Inc.,
  24  *  51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA.
  25  */
  26
  27 #include "splat-internal.h"
  28
  29 #define SPLAT_KRNG_NAME                 "krng"
  30 #define SPLAT_KRNG_DESC                 "Kernel Random Number Generator Tests"
  31
  32 #define SPLAT_KRNG_TEST1_ID             0x0301
  33 #define SPLAT_KRNG_TEST1_NAME           "freq"
  34 #define SPLAT_KRNG_TEST1_DESC           "Frequency Test"
  35
  36 #define KRNG_NUM_BITS                   1048576
  37 #define KRNG_NUM_BYTES                  (KRNG_NUM_BITS >> 3)
  38 #define KRNG_NUM_BITS_DIV2              (KRNG_NUM_BITS >> 1)
  39 #define KRNG_ERROR_RANGE                2097
  40
  41 /* Random Number Generator Tests
  42    There can be meny more tests on quality of the
  43    random number generator.  For now we are only
  44    testing the frequency of particular bits.
  45    We could also test consecutive sequences,
  46    randomness within a particular block, etc.
  47    but is probably not necessary for our purposes */
  48
  49 static int
  50 splat_krng_test1(struct file *file, void *arg)
  51 {
  52         uint8_t *buf;
  53         int i, j, diff, num = 0, rc = 0;
  54
  55         buf = kmalloc(sizeof(*buf) * KRNG_NUM_BYTES, GFP_KERNEL);
  56         if (buf == NULL) {
  57                 rc = -ENOMEM;
  58                 goto out;
  59         }
  60
  61         memset(buf, 0, sizeof(*buf) * KRNG_NUM_BYTES);
  62
  63         /* Always succeeds */
  64         random_get_pseudo_bytes(buf, sizeof(uint8_t) * KRNG_NUM_BYTES);
  65
  66         for (i = 0; i < KRNG_NUM_BYTES; i++) {
  67                 uint8_t tmp = buf[i];
  68                 for (j = 0; j < 8; j++) {
  69                         uint8_t tmp2 = ((tmp >> j) & 0x01);
  70                         if (tmp2 == 1) {
  71                                 num++;
  72                         }
  73                 }
  74         }
  75
  76         kfree(buf);
  77
  78         diff = KRNG_NUM_BITS_DIV2 - num;
  79         if (diff < 0)
  80                 diff *= -1;
  81
  82         splat_print(file, "Test 1 Number of ones: %d\n", num);
  83         splat_print(file, "Test 1 Difference from expected: %d Allowed: %d\n",
  84                   diff, KRNG_ERROR_RANGE);
  85
  86         if (diff > KRNG_ERROR_RANGE)
  87                 rc = -ERANGE;
  88 out:
  89         return rc;
  90 }
  91
  92 splat_subsystem_t *
  93 splat_krng_init(void)
  94 {
  95         splat_subsystem_t *sub;
  96
  97         sub = kmalloc(sizeof(*sub), GFP_KERNEL);
  98         if (sub == NULL)
  99                 return NULL;
 100
 101         memset(sub, 0, sizeof(*sub));
 102         strncpy(sub->desc.name, SPLAT_KRNG_NAME, SPLAT_NAME_SIZE);
 103         strncpy(sub->desc.desc, SPLAT_KRNG_DESC, SPLAT_DESC_SIZE);
 104         INIT_LIST_HEAD(&sub->subsystem_list);
 105         INIT_LIST_HEAD(&sub->test_list);
 106         spin_lock_init(&sub->test_lock);
 107         sub->desc.id = SPLAT_SUBSYSTEM_KRNG;
 108
 109         SPLAT_TEST_INIT(sub, SPLAT_KRNG_TEST1_NAME, SPLAT_KRNG_TEST1_DESC,
 110                       SPLAT_KRNG_TEST1_ID, splat_krng_test1);
 111
 112         return sub;
 113 }
 114
 115 void
 116 splat_krng_fini(splat_subsystem_t *sub)
 117 {
 118         ASSERT(sub);
 119
 120         SPLAT_TEST_FINI(sub, SPLAT_KRNG_TEST1_ID);
 121
 122         kfree(sub);
 123 }
 124
 125 int
 126 splat_krng_id(void) {
 127         return SPLAT_SUBSYSTEM_KRNG;
 128 }