string/test-strcmp.c

   1 /* Test and measure strcmp and wcscmp functions.
   2    Copyright (C) 1999-2023 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, see
  17    <https://www.gnu.org/licenses/>.  */
  18
  19 #define TEST_LEN (getpagesize () * 3)
  20 #define MIN_PAGE_SIZE (TEST_LEN + 2 * getpagesize ())
  21
  22 #define TEST_MAIN
  23 #ifdef WIDE
  24 # define TEST_NAME "wcscmp"
  25 #else
  26 # define TEST_NAME "strcmp"
  27 #endif
  28 #include "test-string.h"
  29 #include <support/test-driver.h>
  30
  31 #ifdef WIDE
  32 # include <wchar.h>
  33
  34 # define L(str) L##str
  35 # define STRCMP wcscmp
  36 # define STRCPY wcscpy
  37 # define STRLEN wcslen
  38 # define MEMCPY wmemcpy
  39 # define SIMPLE_STRCMP simple_wcscmp
  40 # define CHAR wchar_t
  41 # define UCHAR wchar_t
  42 # define CHARBYTES 4
  43 # define CHARBYTESLOG 2
  44 # define CHARALIGN __alignof__ (CHAR)
  45 # define MIDCHAR 0x7fffffff
  46 # define LARGECHAR 0xfffffffe
  47 # define CHAR__MAX WCHAR_MAX
  48 # define CHAR__MIN WCHAR_MIN
  49
  50 /* Wcscmp uses signed semantics for comparison, not unsigned */
  51 /* Avoid using subtraction since possible overflow */
  52
  53 int
  54 simple_wcscmp (const wchar_t *s1, const wchar_t *s2)
  55 {
  56   wchar_t c1, c2;
  57   do
  58     {
  59       c1 = *s1++;
  60       c2 = *s2++;
  61       if (c2 == L'\0')
  62       return c1 - c2;
  63     }
  64   while (c1 == c2);
  65
  66   return c1 < c2 ? -1 : 1;
  67 }
  68
  69 #else
  70 # include <limits.h>
  71
  72 # define L(str) str
  73 # define STRCMP strcmp
  74 # define STRCPY strcpy
  75 # define STRLEN strlen
  76 # define MEMCPY memcpy
  77 # define SIMPLE_STRCMP simple_strcmp
  78 # define CHAR char
  79 # define UCHAR unsigned char
  80 # define CHARBYTES 1
  81 # define CHARBYTESLOG 0
  82 # define CHARALIGN 1
  83 # define MIDCHAR 0x7f
  84 # define LARGECHAR 0xfe
  85 # define CHAR__MAX CHAR_MAX
  86 # define CHAR__MIN CHAR_MIN
  87
  88 /* Strcmp uses unsigned semantics for comparison. */
  89 int
  90 simple_strcmp (const char *s1, const char *s2)
  91 {
  92   int ret;
  93
  94   while ((ret = *(unsigned char *) s1 - *(unsigned char*) s2++) == 0 && *s1++);
  95   return ret;
  96 }
  97
  98 #endif
  99
 100 typedef int (*proto_t) (const CHAR *, const CHAR *);
 101
 102 IMPL (STRCMP, 1)
 103
 104 /* Also check the default implementation.  */
 105 #undef STRCMP
 106 #undef libc_hidden_builtin_def
 107 #define libc_hidden_builtin_def(a)
 108 #undef libc_hidden_def
 109 #define libc_hidden_def(a)
 110 #undef weak_alias
 111 #define weak_alias(a, b)
 112 #undef attribute_hidden
 113 #define attribute_hidden
 114 #ifndef WIDE
 115 # define STRCMP __strcmp_default
 116 # include "string/strcmp.c"
 117 # define STRCMP_DEFAULT STRCMP
 118 #else
 119 # define WCSCMP __wcscmp_default
 120 # include "wcsmbs/wcscmp.c"
 121 # define STRCMP_DEFAULT WCSCMP
 122 #endif
 123 IMPL (STRCMP_DEFAULT, 1)
 124
 125
 126 static int
 127 check_result (impl_t *impl,
 128              const CHAR *s1, const CHAR *s2,
 129              int exp_result)
 130 {
 131   int result = CALL (impl, s1, s2);
 132   if ((exp_result == 0 && result != 0)
 133       || (exp_result < 0 && result >= 0)
 134       || (exp_result > 0 && result <= 0))
 135     {
 136       error (0, 0, "Wrong result in function %s %d %d", impl->name,
 137              result, exp_result);
 138       ret = 1;
 139       return -1;
 140     }
 141
 142   return 0;
 143 }
 144
 145 static void
 146 do_one_test (impl_t *impl,
 147              const CHAR *s1, const CHAR *s2,
 148              int exp_result)
 149 {
 150   if (check_result (impl, s1, s2, exp_result) < 0)
 151     return;
 152 }
 153
 154 static void
 155 do_test (size_t align1, size_t align2, size_t len, int max_char,
 156          int exp_result)
 157 {
 158   size_t i;
 159
 160   CHAR *s1, *s2;
 161
 162   if (len == 0)
 163     return;
 164
 165   align1 &= ~(CHARBYTES - 1);
 166   align2 &= ~(CHARBYTES - 1);
 167
 168   align1 &= getpagesize () - 1;
 169   if (align1 + (len + 1) * CHARBYTES >= page_size)
 170     return;
 171
 172   align2 &= getpagesize () - 1;
 173   if (align2 + (len + 1) * CHARBYTES >= page_size)
 174     return;
 175
 176   /* Put them close to the end of page.  */
 177   i = align1 + CHARBYTES * (len + 2);
 178   s1 = (CHAR *)(buf1 + ((page_size - i) / 16 * 16) + align1);
 179   i = align2 + CHARBYTES * (len + 2);
 180   s2 = (CHAR *)(buf2 + ((page_size - i) / 16 * 16) + align2);
 181
 182   for (i = 0; i < len; i++)
 183     s1[i] = s2[i] = 1 + (23 << ((CHARBYTES - 1) * 8)) * i % max_char;
 184
 185   s1[len] = s2[len] = 0;
 186   s1[len + 1] = 23;
 187   s2[len + 1] = 24 + exp_result;
 188   s2[len - 1] -= exp_result;
 189
 190   FOR_EACH_IMPL (impl, 0)
 191   do_one_test (impl, s1, s2, exp_result);
 192 }
 193
 194
 195 static void
 196 do_random_tests (void)
 197 {
 198         UCHAR *p1 = (UCHAR *) (buf1 + page_size - 512 * CHARBYTES);
 199         UCHAR *p2 = (UCHAR *) (buf2 + page_size - 512 * CHARBYTES);
 200
 201         for (size_t n = 0; n < ITERATIONS; n++)
 202           {
 203             /* for wcscmp case align1 and align2 mean here alignment
 204                in wchar_t symbols, it equal 4*k alignment in bytes, we
 205                don't check other alignments like for example
 206                p1 = (wchar_t *)(buf1 + 1)
 207                because it's wrong using of wchar_t type.  */
 208             size_t align1 = random () & 31;
 209             size_t align2;
 210             if (random () & 1)
 211               align2 = random () & 31;
 212             else
 213               align2 = align1 + (random () & 24);
 214             size_t pos = random () & 511;
 215             size_t j = align1 > align2 ? align1 : align2;
 216             if (pos + j >= 511)
 217               pos = 510 - j - (random () & 7);
 218             size_t len1 = random () & 511;
 219             if (pos >= len1 && (random () & 1))
 220               len1 = pos + (random () & 7);
 221             if (len1 + j >= 512)
 222               len1 = 511 - j - (random () & 7);
 223             size_t len2;
 224             if (pos >= len1)
 225               len2 = len1;
 226             else
 227               len2 = len1 + (len1 != 511 - j ? random () % (511 - j - len1) : 0);
 228             j = (pos > len2 ? pos : len2) + align1 + 64;
 229             if (j > 512)
 230               j = 512;
 231             for (size_t i = 0; i < j; ++i)
 232               {
 233                 p1[i] = random () & 255;
 234                 if (i < len1 + align1 && !p1[i])
 235                   {
 236                     p1[i] = random () & 255;
 237                     if (!p1[i])
 238                       p1[i] = 1 + (random () & 127);
 239                   }
 240               }
 241             for (size_t i = 0; i < j; ++i)
 242               {
 243                 p2[i] = random () & 255;
 244                 if (i < len2 + align2 && !p2[i])
 245                   {
 246                     p2[i] = random () & 255;
 247                     if (!p2[i])
 248                       p2[i] = 1 + (random () & 127);
 249                   }
 250               }
 251
 252             int result = 0;
 253             MEMCPY (p2 + align2, p1 + align1, pos);
 254             if (pos < len1)
 255               {
 256                 if (p2[align2 + pos] == p1[align1 + pos])
 257                   {
 258                     p2[align2 + pos] = random () & 255;
 259                     if (p2[align2 + pos] == p1[align1 + pos])
 260                       p2[align2 + pos] = p1[align1 + pos] + 3 + (random () & 127);
 261                   }
 262
 263                 if (p1[align1 + pos] < p2[align2 + pos])
 264                   result = -1;
 265                 else
 266                   result = 1;
 267               }
 268             p1[len1 + align1] = 0;
 269             p2[len2 + align2] = 0;
 270
 271             FOR_EACH_IMPL (impl, 1)
 272               {
 273                 int r = CALL (impl, (CHAR *) (p1 + align1), (CHAR *) (p2 + align2));
 274                 /* Test whether on 64-bit architectures where ABI requires
 275                    callee to promote has the promotion been done.  */
 276                 asm ("" : "=g" (r) : "0" (r));
 277                 if ((r == 0 && result)
 278                     || (r < 0 && result >= 0)
 279                     || (r > 0 && result <= 0))
 280                   {
 281                     error (0, 0, "Iteration %zd - wrong result in function %s (align in bytes: %zd, align in bytes: %zd, len1:  %zd, len2: %zd, pos: %zd) %d != %d, p1 %p p2 %p",
 282                            n, impl->name, (size_t) (p1 + align1) & 63, (size_t) (p1 + align2) & 63, len1, len2, pos, r, result, p1, p2);
 283                     ret = 1;
 284                   }
 285               }
 286      }
 287 }
 288
 289 static void
 290 check (void)
 291 {
 292   CHAR *s1 = (CHAR *) (buf1 + 0xb2c);
 293   CHAR *s2 = (CHAR *) (buf1 + 0xfd8);
 294
 295   STRCPY(s1, L("abcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrs"));
 296   STRCPY(s2, L("abcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyzabcdefghijkLMNOPQRSTUV"));
 297
 298   /* Check correct working for negatives values */
 299
 300   s1[0] = 1;
 301   s2[0] = 1;
 302   s1[1] = 1;
 303   s2[1] = 1;
 304   s1[2] = -1;
 305   s2[2] = 3;
 306   s1[3] = 0;
 307   s2[3] = -1;
 308
 309   /* Check possible overflow bug, actual more for wcscmp */
 310
 311   s1[7] = CHAR__MIN;
 312   s2[7] = CHAR__MAX;
 313
 314   size_t l1 = STRLEN (s1);
 315   size_t l2 = STRLEN (s2);
 316
 317   for (size_t i1 = 0; i1 < l1; i1++)
 318     for (size_t i2 = 0; i2 < l2; i2++)
 319       {
 320                 int exp_result = SIMPLE_STRCMP (s1 + i1, s2 + i2);
 321                 FOR_EACH_IMPL (impl, 0)
 322                 check_result (impl, s1 + i1, s2 + i2, exp_result);
 323       }
 324
 325   /* Test cases where there are multiple zero bytes after the first.  */
 326
 327   for (size_t i = 0; i < 16 + 1; i++)
 328     {
 329       s1[i] = 0x00;
 330       s2[i] = 0x00;
 331     }
 332
 333   for (size_t i = 0; i < 16; i++)
 334     {
 335       int exp_result;
 336
 337       for (int val = 0x01; val < 0x100; val++)
 338         {
 339           for (size_t j = 0; j < i; j++)
 340             {
 341               s1[j] = val;
 342               s2[j] = val;
 343             }
 344
 345           s2[i] = val;
 346
 347           exp_result = SIMPLE_STRCMP (s1, s2);
 348           FOR_EACH_IMPL (impl, 0)
 349             check_result (impl, s1, s2, exp_result);
 350         }
 351     }
 352 }
 353
 354 static void
 355 check2 (void)
 356 {
 357   /* To trigger bug 25933, we need a size that is equal to the vector
 358      length times 4. In the case of AVX2 for Intel, we need 32 * 4.  We
 359      make this test generic and run it for all architectures as additional
 360      boundary testing for such related algorithms.  */
 361   size_t size = 32 * 4;
 362   CHAR *s1 = (CHAR *) (buf1 + (BUF1PAGES - 1) * page_size);
 363   CHAR *s2 = (CHAR *) (buf2 + (BUF1PAGES - 1) * page_size);
 364   int exp_result;
 365
 366   memset (s1, 'a', page_size);
 367   memset (s2, 'a', page_size);
 368   s1[(page_size / CHARBYTES) - 1] = (CHAR) 0;
 369   s2[(page_size / CHARBYTES) - 1] = (CHAR) 0;
 370
 371   /* Iterate over a size that is just below where we expect the bug to
 372      trigger up to the size we expect will trigger the bug e.g. [99-128].
 373      Likewise iterate the start of two strings between 30 and 31 bytes
 374      away from the boundary to simulate alignment changes.  */
 375   for (size_t s = 99; s <= size; s++)
 376     for (size_t s1a = 30; s1a < 32; s1a++)
 377       for (size_t s2a = 30; s2a < 32; s2a++)
 378         {
 379           CHAR *s1p = s1 + (page_size / CHARBYTES - s) - s1a;
 380           CHAR *s2p = s2 + (page_size / CHARBYTES - s) - s2a;
 381           exp_result = SIMPLE_STRCMP (s1p, s2p);
 382           FOR_EACH_IMPL (impl, 0)
 383             check_result (impl, s1p, s2p, exp_result);
 384         }
 385 }
 386
 387 static void
 388 check3 (void)
 389 {
 390   size_t size = 0xd000 + 0x4000;
 391   CHAR *s1, *s2;
 392   CHAR *buffer1 = mmap (NULL, size, PROT_READ | PROT_WRITE,
 393                         MAP_PRIVATE | MAP_ANON, -1, 0);
 394   CHAR *buffer2 = mmap (NULL, size, PROT_READ | PROT_WRITE,
 395                         MAP_PRIVATE | MAP_ANON, -1, 0);
 396   if (buffer1 == MAP_FAILED || buffer1 == MAP_FAILED)
 397     error (EXIT_UNSUPPORTED, errno, "mmap failed");
 398
 399   s1 = (CHAR *) (buffer1 + 0x8f8 / sizeof (CHAR));
 400   s2 = (CHAR *) (buffer2 + 0xcff3 / sizeof (CHAR));
 401
 402   STRCPY(s1, L("/export/redhat/rpms/BUILD/java-1.8.0-openjdk-1.8.0.312.b07-2.fc35.x86_64/openjdk/langtools/src/share/classes/com/sun/tools/doclets/internal/toolkit/util/PathDocFileFactory.java"));
 403   STRCPY(s2, L("/export/redhat/rpms/BUILD/java-1.8.0-openjdk-1.8.0.312.b07-2.fc35.x86_64/openjdk/langtools/src/share/classes/com/sun/tools/doclets/internal/toolkit/taglets/ThrowsTaglet.java"));
 404
 405   int exp_result = SIMPLE_STRCMP (s1, s2);
 406   FOR_EACH_IMPL (impl, 0)
 407     check_result (impl, s1, s2, exp_result);
 408
 409   munmap ((void *) buffer1, size);
 410   munmap ((void *) buffer2, size);
 411 }
 412
 413 int
 414 test_main (void)
 415 {
 416   size_t i, j, k;
 417   const size_t test_len = MIN(TEST_LEN, 3 * 4096);
 418   test_init ();
 419   check();
 420   check2 ();
 421   check3 ();
 422
 423   printf ("%23s", "");
 424   FOR_EACH_IMPL (impl, 0)
 425     printf ("\t%s", impl->name);
 426   putchar ('\n');
 427
 428   for (i = 1; i < 32; ++i)
 429     {
 430       do_test (CHARBYTES * i, CHARBYTES * i, i, MIDCHAR, 0);
 431       do_test (CHARBYTES * i, CHARBYTES * i, i, MIDCHAR, 1);
 432       do_test (CHARBYTES * i, CHARBYTES * i, i, MIDCHAR, -1);
 433     }
 434
 435   for (i = 1; i < 10 + CHARBYTESLOG; ++i)
 436     {
 437       do_test (0, 0, 2 << i, MIDCHAR, 0);
 438       do_test (0, 0, 2 << i, LARGECHAR, 0);
 439       do_test (0, 0, 2 << i, MIDCHAR, 1);
 440       do_test (0, 0, 2 << i, LARGECHAR, 1);
 441       do_test (0, 0, 2 << i, MIDCHAR, -1);
 442       do_test (0, 0, 2 << i, LARGECHAR, -1);
 443       do_test (0, CHARBYTES * i, 2 << i, MIDCHAR, 1);
 444       do_test (CHARBYTES * i, CHARBYTES * (i + 1), 2 << i, LARGECHAR, 1);
 445     }
 446
 447   for (i = 1; i < 8; ++i)
 448     {
 449       do_test (CHARBYTES * i, 2 * CHARBYTES * i, 8 << i, MIDCHAR, 0);
 450       do_test (2 * CHARBYTES * i, CHARBYTES * i, 8 << i, LARGECHAR, 0);
 451       do_test (CHARBYTES * i, 2 * CHARBYTES * i, 8 << i, MIDCHAR, 1);
 452       do_test (2 * CHARBYTES * i, CHARBYTES * i, 8 << i, LARGECHAR, 1);
 453       do_test (CHARBYTES * i, 2 * CHARBYTES * i, 8 << i, MIDCHAR, -1);
 454       do_test (2 * CHARBYTES * i, CHARBYTES * i, 8 << i, LARGECHAR, -1);
 455     }
 456
 457   for (j = 0; j < 160; ++j)
 458     {
 459       for (i = 0; i < test_len;)
 460         {
 461           do_test (getpagesize () - j - 1, 0, i, 127, 0);
 462           do_test (getpagesize () - j - 1, 0, i, 127, 1);
 463           do_test (getpagesize () - j - 1, 0, i, 127, -1);
 464
 465           do_test (getpagesize () - j - 1, j, i, 127, 0);
 466           do_test (getpagesize () - j - 1, j, i, 127, 1);
 467           do_test (getpagesize () - j - 1, j, i, 127, -1);
 468
 469           do_test (0, getpagesize () - j - 1, i, 127, 0);
 470           do_test (0, getpagesize () - j - 1, i, 127, 1);
 471           do_test (0, getpagesize () - j - 1, i, 127, -1);
 472
 473           do_test (j, getpagesize () - j - 1, i, 127, 0);
 474           do_test (j, getpagesize () - j - 1, i, 127, 1);
 475           do_test (j, getpagesize () - j - 1, i, 127, -1);
 476
 477           for (k = 2; k <= 128; k += k)
 478             {
 479               do_test (getpagesize () - k, getpagesize () - j - 1, i, 127, 0);
 480               do_test (getpagesize () - k - 1, getpagesize () - j - 1, i, 127,
 481                        0);
 482               do_test (getpagesize () - k, getpagesize () - j - 1, i, 127, 1);
 483               do_test (getpagesize () - k - 1, getpagesize () - j - 1, i, 127,
 484                        1);
 485               do_test (getpagesize () - k, getpagesize () - j - 1, i, 127, -1);
 486               do_test (getpagesize () - k - 1, getpagesize () - j - 1, i, 127,
 487                        -1);
 488             }
 489
 490           if (i < 32)
 491             {
 492               i += 1;
 493             }
 494           else if (i < 161)
 495             {
 496               i += 7;
 497             }
 498           else if (i + 161 < test_len)
 499             {
 500               i += 31;
 501               i *= 17;
 502               i /= 16;
 503               if (i + 161 > test_len)
 504                 {
 505                   i = test_len - 160;
 506                 }
 507             }
 508           else if (i + 32 < test_len)
 509             {
 510               i += 7;
 511             }
 512           else
 513             {
 514               i += 1;
 515             }
 516         }
 517     }
 518
 519   do_random_tests ();
 520   return ret;
 521 }
 522
 523 #include <support/test-driver.c>