lib/test_string.c

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