lib/test_string.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 #include <linux/module.h>
   3 #include <linux/printk.h>
   4 #include <linux/slab.h>
   5 #include <linux/string.h>
   6
   7 static __init int memset16_selftest(void)
   8 {
   9         unsigned i, j, k;
  10         u16 v, *p;
  11
  12         p = kmalloc(256 * 2 * 2, GFP_KERNEL);
  13         if (!p)
  14                 return -1;
  15
  16         for (i = 0; i < 256; i++) {
  17                 for (j = 0; j < 256; j++) {
  18                         memset(p, 0xa1, 256 * 2 * sizeof(v));
  19                         memset16(p + i, 0xb1b2, j);
  20                         for (k = 0; k < 512; k++) {
  21                                 v = p[k];
  22                                 if (k < i) {
  23                                         if (v != 0xa1a1)
  24                                                 goto fail;
  25                                 } else if (k < i + j) {
  26                                         if (v != 0xb1b2)
  27                                                 goto fail;
  28                                 } else {
  29                                         if (v != 0xa1a1)
  30                                                 goto fail;
  31                                 }
  32                         }
  33                 }
  34         }
  35
  36 fail:
  37         kfree(p);
  38         if (i < 256)
  39                 return (i << 24) | (j << 16) | k;
  40         return 0;
  41 }
  42
  43 static __init int memset32_selftest(void)
  44 {
  45         unsigned i, j, k;
  46         u32 v, *p;
  47
  48         p = kmalloc(256 * 2 * 4, GFP_KERNEL);
  49         if (!p)
  50                 return -1;
  51
  52         for (i = 0; i < 256; i++) {
  53                 for (j = 0; j < 256; j++) {
  54                         memset(p, 0xa1, 256 * 2 * sizeof(v));
  55                         memset32(p + i, 0xb1b2b3b4, j);
  56                         for (k = 0; k < 512; k++) {
  57                                 v = p[k];
  58                                 if (k < i) {
  59                                         if (v != 0xa1a1a1a1)
  60                                                 goto fail;
  61                                 } else if (k < i + j) {
  62                                         if (v != 0xb1b2b3b4)
  63                                                 goto fail;
  64                                 } else {
  65                                         if (v != 0xa1a1a1a1)
  66                                                 goto fail;
  67                                 }
  68                         }
  69                 }
  70         }
  71
  72 fail:
  73         kfree(p);
  74         if (i < 256)
  75                 return (i << 24) | (j << 16) | k;
  76         return 0;
  77 }
  78
  79 static __init int memset64_selftest(void)
  80 {
  81         unsigned i, j, k;
  82         u64 v, *p;
  83
  84         p = kmalloc(256 * 2 * 8, GFP_KERNEL);
  85         if (!p)
  86                 return -1;
  87
  88         for (i = 0; i < 256; i++) {
  89                 for (j = 0; j < 256; j++) {
  90                         memset(p, 0xa1, 256 * 2 * sizeof(v));
  91                         memset64(p + i, 0xb1b2b3b4b5b6b7b8ULL, j);
  92                         for (k = 0; k < 512; k++) {
  93                                 v = p[k];
  94                                 if (k < i) {
  95                                         if (v != 0xa1a1a1a1a1a1a1a1ULL)
  96                                                 goto fail;
  97                                 } else if (k < i + j) {
  98                                         if (v != 0xb1b2b3b4b5b6b7b8ULL)
  99                                                 goto fail;
 100                                 } else {
 101                                         if (v != 0xa1a1a1a1a1a1a1a1ULL)
 102                                                 goto fail;
 103                                 }
 104                         }
 105                 }
 106         }
 107
 108 fail:
 109         kfree(p);
 110         if (i < 256)
 111                 return (i << 24) | (j << 16) | k;
 112         return 0;
 113 }
 114
 115 static __init int string_selftest_init(void)
 116 {
 117         int test, subtest;
 118
 119         test = 1;
 120         subtest = memset16_selftest();
 121         if (subtest)
 122                 goto fail;
 123
 124         test = 2;
 125         subtest = memset32_selftest();
 126         if (subtest)
 127                 goto fail;
 128
 129         test = 3;
 130         subtest = memset64_selftest();
 131         if (subtest)
 132                 goto fail;
 133
 134         pr_info("String selftests succeeded\n");
 135         return 0;
 136 fail:
 137         pr_crit("String selftest failure %d.%08x\n", test, subtest);
 138         return 0;
 139 }
 140
 141 module_init(string_selftest_init);
 142 MODULE_LICENSE("GPL v2");