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 | 0x8000;
  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 | 0x8000;
  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 | 0x8000;
 112         return 0;
 113 }
 114
 115 static __init int strchr_selftest(void)
 116 {
 117         const char *test_string = "abcdefghijkl";
 118         const char *empty_string = "";
 119         char *result;
 120         int i;
 121
 122         for (i = 0; i < strlen(test_string) + 1; i++) {
 123                 result = strchr(test_string, test_string[i]);
 124                 if (result - test_string != i)
 125                         return i + 'a';
 126         }
 127
 128         result = strchr(empty_string, '\0');
 129         if (result != empty_string)
 130                 return 0x101;
 131
 132         result = strchr(empty_string, 'a');
 133         if (result)
 134                 return 0x102;
 135
 136         result = strchr(test_string, 'z');
 137         if (result)
 138                 return 0x103;
 139
 140         return 0;
 141 }
 142
 143 static __init int strnchr_selftest(void)
 144 {
 145         const char *test_string = "abcdefghijkl";
 146         const char *empty_string = "";
 147         char *result;
 148         int i, j;
 149
 150         for (i = 0; i < strlen(test_string) + 1; i++) {
 151                 for (j = 0; j < strlen(test_string) + 2; j++) {
 152                         result = strnchr(test_string, j, test_string[i]);
 153                         if (j <= i) {
 154                                 if (!result)
 155                                         continue;
 156                                 return ((i + 'a') << 8) | j;
 157                         }
 158                         if (result - test_string != i)
 159                                 return ((i + 'a') << 8) | j;
 160                 }
 161         }
 162
 163         result = strnchr(empty_string, 0, '\0');
 164         if (result)
 165                 return 0x10001;
 166
 167         result = strnchr(empty_string, 1, '\0');
 168         if (result != empty_string)
 169                 return 0x10002;
 170
 171         result = strnchr(empty_string, 1, 'a');
 172         if (result)
 173                 return 0x10003;
 174
 175         result = strnchr(NULL, 0, '\0');
 176         if (result)
 177                 return 0x10004;
 178
 179         return 0;
 180 }
 181
 182 static __exit void string_selftest_remove(void)
 183 {
 184 }
 185
 186 static __init int string_selftest_init(void)
 187 {
 188         int test, subtest;
 189
 190         test = 1;
 191         subtest = memset16_selftest();
 192         if (subtest)
 193                 goto fail;
 194
 195         test = 2;
 196         subtest = memset32_selftest();
 197         if (subtest)
 198                 goto fail;
 199
 200         test = 3;
 201         subtest = memset64_selftest();
 202         if (subtest)
 203                 goto fail;
 204
 205         test = 4;
 206         subtest = strchr_selftest();
 207         if (subtest)
 208                 goto fail;
 209
 210         test = 5;
 211         subtest = strnchr_selftest();
 212         if (subtest)
 213                 goto fail;
 214
 215         pr_info("String selftests succeeded\n");
 216         return 0;
 217 fail:
 218         pr_crit("String selftest failure %d.%08x\n", test, subtest);
 219         return 0;
 220 }
 221
 222 module_init(string_selftest_init);
 223 module_exit(string_selftest_remove);
 224 MODULE_LICENSE("GPL v2");