module/splat/splat-random.c

   1 /*****************************************************************************\
   2  *  Copyright (C) 2007-2010 Lawrence Livermore National Security, LLC.
   3  *  Copyright (C) 2007 The Regents of the University of California.
   4  *  Produced at Lawrence Livermore National Laboratory (cf, DISCLAIMER).
   5  *  Written by Brian Behlendorf <behlendorf1@llnl.gov>.
   6  *  UCRL-CODE-235197
   7  *
   8  *  This file is part of the SPL, Solaris Porting Layer.
   9  *  For details, see <http://zfsonlinux.org/>.
  10  *
  11  *  The SPL is free software; you can redistribute it and/or modify it
  12  *  under the terms of the GNU General Public License as published by the
  13  *  Free Software Foundation; either version 2 of the License, or (at your
  14  *  option) any later version.
  15  *
  16  *  The SPL is distributed in the hope that it will be useful, but WITHOUT
  17  *  ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  18  *  FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  19  *  for more details.
  20  *
  21  *  You should have received a copy of the GNU General Public License along
  22  *  with the SPL.  If not, see <http://www.gnu.org/licenses/>.
  23  *****************************************************************************
  24  *  Solaris Porting LAyer Tests (SPLAT) Random Number Generator Tests.
  25 \*****************************************************************************/
  26
  27 #include <sys/random.h>
  28 #include <sys/kmem.h>
  29 #include "splat-internal.h"
  30
  31 #define SPLAT_KRNG_NAME                 "krng"
  32 #define SPLAT_KRNG_DESC                 "Kernel Random Number Generator Tests"
  33
  34 #define SPLAT_KRNG_TEST1_ID             0x0301
  35 #define SPLAT_KRNG_TEST1_NAME           "freq"
  36 #define SPLAT_KRNG_TEST1_DESC           "Frequency Test"
  37
  38 #define KRNG_NUM_BITS                   1048576
  39 #define KRNG_NUM_BYTES                  (KRNG_NUM_BITS >> 3)
  40 #define KRNG_NUM_BITS_DIV2              (KRNG_NUM_BITS >> 1)
  41 #define KRNG_ERROR_RANGE                2097
  42
  43 /* Random Number Generator Tests
  44    There can be meny more tests on quality of the
  45    random number generator.  For now we are only
  46    testing the frequency of particular bits.
  47    We could also test consecutive sequences,
  48    randomness within a particular block, etc.
  49    but is probably not necessary for our purposes */
  50
  51 static int
  52 splat_krng_test1(struct file *file, void *arg)
  53 {
  54         uint8_t *buf;
  55         int i, j, diff, num = 0, rc = 0;
  56
  57         buf = kmalloc(sizeof(*buf) * KRNG_NUM_BYTES, GFP_KERNEL);
  58         if (buf == NULL) {
  59                 rc = -ENOMEM;
  60                 goto out;
  61         }
  62
  63         memset(buf, 0, sizeof(*buf) * KRNG_NUM_BYTES);
  64
  65         /* Always succeeds */
  66         random_get_pseudo_bytes(buf, sizeof(uint8_t) * KRNG_NUM_BYTES);
  67
  68         for (i = 0; i < KRNG_NUM_BYTES; i++) {
  69                 uint8_t tmp = buf[i];
  70                 for (j = 0; j < 8; j++) {
  71                         uint8_t tmp2 = ((tmp >> j) & 0x01);
  72                         if (tmp2 == 1) {
  73                                 num++;
  74                         }
  75                 }
  76         }
  77
  78         kfree(buf);
  79
  80         diff = KRNG_NUM_BITS_DIV2 - num;
  81         if (diff < 0)
  82                 diff *= -1;
  83
  84         splat_print(file, "Test 1 Number of ones: %d\n", num);
  85         splat_print(file, "Test 1 Difference from expected: %d Allowed: %d\n",
  86                   diff, KRNG_ERROR_RANGE);
  87
  88         if (diff > KRNG_ERROR_RANGE)
  89                 rc = -ERANGE;
  90 out:
  91         return rc;
  92 }
  93
  94 splat_subsystem_t *
  95 splat_krng_init(void)
  96 {
  97         splat_subsystem_t *sub;
  98
  99         sub = kmalloc(sizeof(*sub), GFP_KERNEL);
 100         if (sub == NULL)
 101                 return NULL;
 102
 103         memset(sub, 0, sizeof(*sub));
 104         strncpy(sub->desc.name, SPLAT_KRNG_NAME, SPLAT_NAME_SIZE);
 105         strncpy(sub->desc.desc, SPLAT_KRNG_DESC, SPLAT_DESC_SIZE);
 106         INIT_LIST_HEAD(&sub->subsystem_list);
 107         INIT_LIST_HEAD(&sub->test_list);
 108         spin_lock_init(&sub->test_lock);
 109         sub->desc.id = SPLAT_SUBSYSTEM_KRNG;
 110
 111         splat_test_init(sub, SPLAT_KRNG_TEST1_NAME, SPLAT_KRNG_TEST1_DESC,
 112                       SPLAT_KRNG_TEST1_ID, splat_krng_test1);
 113
 114         return sub;
 115 }
 116
 117 void
 118 splat_krng_fini(splat_subsystem_t *sub)
 119 {
 120         ASSERT(sub);
 121
 122         splat_test_fini(sub, SPLAT_KRNG_TEST1_ID);
 123
 124         kfree(sub);
 125 }
 126
 127 int
 128 splat_krng_id(void) {
 129         return SPLAT_SUBSYSTEM_KRNG;
 130 }