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_SUBSYSTEM_KRNG            0x0300
  30 #define SPLAT_KRNG_NAME                 "krng"
  31 #define SPLAT_KRNG_DESC                 "Kernel Random Number Generator Tests"
  32
  33 #define SPLAT_KRNG_TEST1_ID             0x0301
  34 #define SPLAT_KRNG_TEST1_NAME           "freq"
  35 #define SPLAT_KRNG_TEST1_DESC           "Frequency Test"
  36
  37 #define KRNG_NUM_BITS                   1048576
  38 #define KRNG_NUM_BYTES                  (KRNG_NUM_BITS >> 3)
  39 #define KRNG_NUM_BITS_DIV2              (KRNG_NUM_BITS >> 1)
  40 #define KRNG_ERROR_RANGE                2097
  41
  42 /* Random Number Generator Tests
  43    There can be meny more tests on quality of the
  44    random number generator.  For now we are only
  45    testing the frequency of particular bits.
  46    We could also test consecutive sequences,
  47    randomness within a particular block, etc.
  48    but is probably not necessary for our purposes */
  49
  50 static int
  51 splat_krng_test1(struct file *file, void *arg)
  52 {
  53         uint8_t *buf;
  54         int i, j, diff, num = 0, rc = 0;
  55
  56         buf = kmalloc(sizeof(*buf) * KRNG_NUM_BYTES, GFP_KERNEL);
  57         if (buf == NULL) {
  58                 rc = -ENOMEM;
  59                 goto out;
  60         }
  61
  62         memset(buf, 0, sizeof(*buf) * KRNG_NUM_BYTES);
  63
  64         /* Always succeeds */
  65         random_get_pseudo_bytes(buf, sizeof(uint8_t) * KRNG_NUM_BYTES);
  66
  67         for (i = 0; i < KRNG_NUM_BYTES; i++) {
  68                 uint8_t tmp = buf[i];
  69                 for (j = 0; j < 8; j++) {
  70                         uint8_t tmp2 = ((tmp >> j) & 0x01);
  71                         if (tmp2 == 1) {
  72                                 num++;
  73                         }
  74                 }
  75         }
  76
  77         kfree(buf);
  78
  79         diff = KRNG_NUM_BITS_DIV2 - num;
  80         if (diff < 0)
  81                 diff *= -1;
  82
  83         splat_print(file, "Test 1 Number of ones: %d\n", num);
  84         splat_print(file, "Test 1 Difference from expected: %d Allowed: %d\n",
  85                   diff, KRNG_ERROR_RANGE);
  86
  87         if (diff > KRNG_ERROR_RANGE)
  88                 rc = -ERANGE;
  89 out:
  90         return rc;
  91 }
  92
  93 splat_subsystem_t *
  94 splat_krng_init(void)
  95 {
  96         splat_subsystem_t *sub;
  97
  98         sub = kmalloc(sizeof(*sub), GFP_KERNEL);
  99         if (sub == NULL)
 100                 return NULL;
 101
 102         memset(sub, 0, sizeof(*sub));
 103         strncpy(sub->desc.name, SPLAT_KRNG_NAME, SPLAT_NAME_SIZE);
 104         strncpy(sub->desc.desc, SPLAT_KRNG_DESC, SPLAT_DESC_SIZE);
 105         INIT_LIST_HEAD(&sub->subsystem_list);
 106         INIT_LIST_HEAD(&sub->test_list);
 107         spin_lock_init(&sub->test_lock);
 108         sub->desc.id = SPLAT_SUBSYSTEM_KRNG;
 109
 110         SPLAT_TEST_INIT(sub, SPLAT_KRNG_TEST1_NAME, SPLAT_KRNG_TEST1_DESC,
 111                       SPLAT_KRNG_TEST1_ID, splat_krng_test1);
 112
 113         return sub;
 114 }
 115
 116 void
 117 splat_krng_fini(splat_subsystem_t *sub)
 118 {
 119         ASSERT(sub);
 120
 121         SPLAT_TEST_FINI(sub, SPLAT_KRNG_TEST1_ID);
 122
 123         kfree(sub);
 124 }
 125
 126 int
 127 splat_krng_id(void) {
 128         return SPLAT_SUBSYSTEM_KRNG;
 129 }