lib/test_printf.c

   1 /*
   2  * Test cases for printf facility.
   3  */
   4
   5 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
   6
   7 #include <linux/init.h>
   8 #include <linux/kernel.h>
   9 #include <linux/module.h>
  10 #include <linux/printk.h>
  11 #include <linux/random.h>
  12 #include <linux/slab.h>
  13 #include <linux/string.h>
  14
  15 #include <linux/bitmap.h>
  16 #include <linux/dcache.h>
  17 #include <linux/socket.h>
  18 #include <linux/in.h>
  19
  20 #include <linux/gfp.h>
  21 #include <linux/mm.h>
  22
  23 #define BUF_SIZE 256
  24 #define PAD_SIZE 16
  25 #define FILL_CHAR '$'
  26
  27 static unsigned total_tests __initdata;
  28 static unsigned failed_tests __initdata;
  29 static char *test_buffer __initdata;
  30 static char *alloced_buffer __initdata;
  31
  32 static int __printf(4, 0) __init
  33 do_test(int bufsize, const char *expect, int elen,
  34         const char *fmt, va_list ap)
  35 {
  36         va_list aq;
  37         int ret, written;
  38
  39         total_tests++;
  40
  41         memset(alloced_buffer, FILL_CHAR, BUF_SIZE + 2*PAD_SIZE);
  42         va_copy(aq, ap);
  43         ret = vsnprintf(test_buffer, bufsize, fmt, aq);
  44         va_end(aq);
  45
  46         if (ret != elen) {
  47                 pr_warn("vsnprintf(buf, %d, \"%s\", ...) returned %d, expected %d\n",
  48                         bufsize, fmt, ret, elen);
  49                 return 1;
  50         }
  51
  52         if (memchr_inv(alloced_buffer, FILL_CHAR, PAD_SIZE)) {
  53                 pr_warn("vsnprintf(buf, %d, \"%s\", ...) wrote before buffer\n", bufsize, fmt);
  54                 return 1;
  55         }
  56
  57         if (!bufsize) {
  58                 if (memchr_inv(test_buffer, FILL_CHAR, BUF_SIZE + PAD_SIZE)) {
  59                         pr_warn("vsnprintf(buf, 0, \"%s\", ...) wrote to buffer\n",
  60                                 fmt);
  61                         return 1;
  62                 }
  63                 return 0;
  64         }
  65
  66         written = min(bufsize-1, elen);
  67         if (test_buffer[written]) {
  68                 pr_warn("vsnprintf(buf, %d, \"%s\", ...) did not nul-terminate buffer\n",
  69                         bufsize, fmt);
  70                 return 1;
  71         }
  72
  73         if (memchr_inv(test_buffer + written + 1, FILL_CHAR, BUF_SIZE + PAD_SIZE - (written + 1))) {
  74                 pr_warn("vsnprintf(buf, %d, \"%s\", ...) wrote beyond the nul-terminator\n",
  75                         bufsize, fmt);
  76                 return 1;
  77         }
  78
  79         if (memcmp(test_buffer, expect, written)) {
  80                 pr_warn("vsnprintf(buf, %d, \"%s\", ...) wrote '%s', expected '%.*s'\n",
  81                         bufsize, fmt, test_buffer, written, expect);
  82                 return 1;
  83         }
  84         return 0;
  85 }
  86
  87 static void __printf(3, 4) __init
  88 __test(const char *expect, int elen, const char *fmt, ...)
  89 {
  90         va_list ap;
  91         int rand;
  92         char *p;
  93
  94         if (elen >= BUF_SIZE) {
  95                 pr_err("error in test suite: expected output length %d too long. Format was '%s'.\n",
  96                        elen, fmt);
  97                 failed_tests++;
  98                 return;
  99         }
 100
 101         va_start(ap, fmt);
 102
 103         /*
 104          * Every fmt+args is subjected to four tests: Three where we
 105          * tell vsnprintf varying buffer sizes (plenty, not quite
 106          * enough and 0), and then we also test that kvasprintf would
 107          * be able to print it as expected.
 108          */
 109         failed_tests += do_test(BUF_SIZE, expect, elen, fmt, ap);
 110         rand = 1 + prandom_u32_max(elen+1);
 111         /* Since elen < BUF_SIZE, we have 1 <= rand <= BUF_SIZE. */
 112         failed_tests += do_test(rand, expect, elen, fmt, ap);
 113         failed_tests += do_test(0, expect, elen, fmt, ap);
 114
 115         p = kvasprintf(GFP_KERNEL, fmt, ap);
 116         if (p) {
 117                 total_tests++;
 118                 if (memcmp(p, expect, elen+1)) {
 119                         pr_warn("kvasprintf(..., \"%s\", ...) returned '%s', expected '%s'\n",
 120                                 fmt, p, expect);
 121                         failed_tests++;
 122                 }
 123                 kfree(p);
 124         }
 125         va_end(ap);
 126 }
 127
 128 #define test(expect, fmt, ...)                                  \
 129         __test(expect, strlen(expect), fmt, ##__VA_ARGS__)
 130
 131 static void __init
 132 test_basic(void)
 133 {
 134         /* Work around annoying "warning: zero-length gnu_printf format string". */
 135         char nul = '\0';
 136
 137         test("", &nul);
 138         test("100%", "100%%");
 139         test("xxx%yyy", "xxx%cyyy", '%');
 140         __test("xxx\0yyy", 7, "xxx%cyyy", '\0');
 141 }
 142
 143 static void __init
 144 test_number(void)
 145 {
 146         test("0x1234abcd  ", "%#-12x", 0x1234abcd);
 147         test("  0x1234abcd", "%#12x", 0x1234abcd);
 148         test("0|001| 12|+123| 1234|-123|-1234", "%d|%03d|%3d|%+d|% d|%+d|% d", 0, 1, 12, 123, 1234, -123, -1234);
 149         test("0|1|1|128|255", "%hhu|%hhu|%hhu|%hhu|%hhu", 0, 1, 257, 128, -1);
 150         test("0|1|1|-128|-1", "%hhd|%hhd|%hhd|%hhd|%hhd", 0, 1, 257, 128, -1);
 151         test("2015122420151225", "%ho%ho%#ho", 1037, 5282, -11627);
 152         /*
 153          * POSIX/C99: »The result of converting zero with an explicit
 154          * precision of zero shall be no characters.« Hence the output
 155          * from the below test should really be "00|0||| ". However,
 156          * the kernel's printf also produces a single 0 in that
 157          * case. This test case simply documents the current
 158          * behaviour.
 159          */
 160         test("00|0|0|0|0", "%.2d|%.1d|%.0d|%.*d|%1.0d", 0, 0, 0, 0, 0, 0);
 161 #ifndef __CHAR_UNSIGNED__
 162         {
 163                 /*
 164                  * Passing a 'char' to a %02x specifier doesn't do
 165                  * what was presumably the intention when char is
 166                  * signed and the value is negative. One must either &
 167                  * with 0xff or cast to u8.
 168                  */
 169                 char val = -16;
 170                 test("0xfffffff0|0xf0|0xf0", "%#02x|%#02x|%#02x", val, val & 0xff, (u8)val);
 171         }
 172 #endif
 173 }
 174
 175 static void __init
 176 test_string(void)
 177 {
 178         test("", "%s%.0s", "", "123");
 179         test("ABCD|abc|123", "%s|%.3s|%.*s", "ABCD", "abcdef", 3, "123456");
 180         test("1  |  2|3  |  4|5  ", "%-3s|%3s|%-*s|%*s|%*s", "1", "2", 3, "3", 3, "4", -3, "5");
 181         test("1234      ", "%-10.4s", "123456");
 182         test("      1234", "%10.4s", "123456");
 183         /*
 184          * POSIX and C99 say that a negative precision (which is only
 185          * possible to pass via a * argument) should be treated as if
 186          * the precision wasn't present, and that if the precision is
 187          * omitted (as in %.s), the precision should be taken to be
 188          * 0. However, the kernel's printf behave exactly opposite,
 189          * treating a negative precision as 0 and treating an omitted
 190          * precision specifier as if no precision was given.
 191          *
 192          * These test cases document the current behaviour; should
 193          * anyone ever feel the need to follow the standards more
 194          * closely, this can be revisited.
 195          */
 196         test("    ", "%4.*s", -5, "123456");
 197         test("123456", "%.s", "123456");
 198         test("a||", "%.s|%.0s|%.*s", "a", "b", 0, "c");
 199         test("a  |   |   ", "%-3.s|%-3.0s|%-3.*s", "a", "b", 0, "c");
 200 }
 201
 202 #define PLAIN_BUF_SIZE 64       /* leave some space so we don't oops */
 203
 204 #if BITS_PER_LONG == 64
 205
 206 #define PTR_WIDTH 16
 207 #define PTR ((void *)0xffff0123456789abUL)
 208 #define PTR_STR "ffff0123456789ab"
 209 #define PTR_VAL_NO_CRNG "(____ptrval____)"
 210 #define ZEROS "00000000"        /* hex 32 zero bits */
 211
 212 static int __init
 213 plain_format(void)
 214 {
 215         char buf[PLAIN_BUF_SIZE];
 216         int nchars;
 217
 218         nchars = snprintf(buf, PLAIN_BUF_SIZE, "%p", PTR);
 219
 220         if (nchars != PTR_WIDTH)
 221                 return -1;
 222
 223         if (strncmp(buf, PTR_VAL_NO_CRNG, PTR_WIDTH) == 0) {
 224                 pr_warn("crng possibly not yet initialized. plain 'p' buffer contains \"%s\"",
 225                         PTR_VAL_NO_CRNG);
 226                 return 0;
 227         }
 228
 229         if (strncmp(buf, ZEROS, strlen(ZEROS)) != 0)
 230                 return -1;
 231
 232         return 0;
 233 }
 234
 235 #else
 236
 237 #define PTR_WIDTH 8
 238 #define PTR ((void *)0x456789ab)
 239 #define PTR_STR "456789ab"
 240 #define PTR_VAL_NO_CRNG "(ptrval)"
 241
 242 static int __init
 243 plain_format(void)
 244 {
 245         /* Format is implicitly tested for 32 bit machines by plain_hash() */
 246         return 0;
 247 }
 248
 249 #endif  /* BITS_PER_LONG == 64 */
 250
 251 static int __init
 252 plain_hash(void)
 253 {
 254         char buf[PLAIN_BUF_SIZE];
 255         int nchars;
 256
 257         nchars = snprintf(buf, PLAIN_BUF_SIZE, "%p", PTR);
 258
 259         if (nchars != PTR_WIDTH)
 260                 return -1;
 261
 262         if (strncmp(buf, PTR_VAL_NO_CRNG, PTR_WIDTH) == 0) {
 263                 pr_warn("crng possibly not yet initialized. plain 'p' buffer contains \"%s\"",
 264                         PTR_VAL_NO_CRNG);
 265                 return 0;
 266         }
 267
 268         if (strncmp(buf, PTR_STR, PTR_WIDTH) == 0)
 269                 return -1;
 270
 271         return 0;
 272 }
 273
 274 /*
 275  * We can't use test() to test %p because we don't know what output to expect
 276  * after an address is hashed.
 277  */
 278 static void __init
 279 plain(void)
 280 {
 281         int err;
 282
 283         err = plain_hash();
 284         if (err) {
 285                 pr_warn("plain 'p' does not appear to be hashed\n");
 286                 failed_tests++;
 287                 return;
 288         }
 289
 290         err = plain_format();
 291         if (err) {
 292                 pr_warn("hashing plain 'p' has unexpected format\n");
 293                 failed_tests++;
 294         }
 295 }
 296
 297 static void __init
 298 symbol_ptr(void)
 299 {
 300 }
 301
 302 static void __init
 303 kernel_ptr(void)
 304 {
 305         /* We can't test this without access to kptr_restrict. */
 306 }
 307
 308 static void __init
 309 struct_resource(void)
 310 {
 311 }
 312
 313 static void __init
 314 addr(void)
 315 {
 316 }
 317
 318 static void __init
 319 escaped_str(void)
 320 {
 321 }
 322
 323 static void __init
 324 hex_string(void)
 325 {
 326         const char buf[3] = {0xc0, 0xff, 0xee};
 327
 328         test("c0 ff ee|c0:ff:ee|c0-ff-ee|c0ffee",
 329              "%3ph|%3phC|%3phD|%3phN", buf, buf, buf, buf);
 330         test("c0 ff ee|c0:ff:ee|c0-ff-ee|c0ffee",
 331              "%*ph|%*phC|%*phD|%*phN", 3, buf, 3, buf, 3, buf, 3, buf);
 332 }
 333
 334 static void __init
 335 mac(void)
 336 {
 337         const u8 addr[6] = {0x2d, 0x48, 0xd6, 0xfc, 0x7a, 0x05};
 338
 339         test("2d:48:d6:fc:7a:05", "%pM", addr);
 340         test("05:7a:fc:d6:48:2d", "%pMR", addr);
 341         test("2d-48-d6-fc-7a-05", "%pMF", addr);
 342         test("2d48d6fc7a05", "%pm", addr);
 343         test("057afcd6482d", "%pmR", addr);
 344 }
 345
 346 static void __init
 347 ip4(void)
 348 {
 349         struct sockaddr_in sa;
 350
 351         sa.sin_family = AF_INET;
 352         sa.sin_port = cpu_to_be16(12345);
 353         sa.sin_addr.s_addr = cpu_to_be32(0x7f000001);
 354
 355         test("127.000.000.001|127.0.0.1", "%pi4|%pI4", &sa.sin_addr, &sa.sin_addr);
 356         test("127.000.000.001|127.0.0.1", "%piS|%pIS", &sa, &sa);
 357         sa.sin_addr.s_addr = cpu_to_be32(0x01020304);
 358         test("001.002.003.004:12345|1.2.3.4:12345", "%piSp|%pISp", &sa, &sa);
 359 }
 360
 361 static void __init
 362 ip6(void)
 363 {
 364 }
 365
 366 static void __init
 367 ip(void)
 368 {
 369         ip4();
 370         ip6();
 371 }
 372
 373 static void __init
 374 uuid(void)
 375 {
 376         const char uuid[16] = {0x0, 0x1, 0x2, 0x3, 0x4, 0x5, 0x6, 0x7,
 377                                0x8, 0x9, 0xa, 0xb, 0xc, 0xd, 0xe, 0xf};
 378
 379         test("00010203-0405-0607-0809-0a0b0c0d0e0f", "%pUb", uuid);
 380         test("00010203-0405-0607-0809-0A0B0C0D0E0F", "%pUB", uuid);
 381         test("03020100-0504-0706-0809-0a0b0c0d0e0f", "%pUl", uuid);
 382         test("03020100-0504-0706-0809-0A0B0C0D0E0F", "%pUL", uuid);
 383 }
 384
 385 static struct dentry test_dentry[4] __initdata = {
 386         { .d_parent = &test_dentry[0],
 387           .d_name = QSTR_INIT(test_dentry[0].d_iname, 3),
 388           .d_iname = "foo" },
 389         { .d_parent = &test_dentry[0],
 390           .d_name = QSTR_INIT(test_dentry[1].d_iname, 5),
 391           .d_iname = "bravo" },
 392         { .d_parent = &test_dentry[1],
 393           .d_name = QSTR_INIT(test_dentry[2].d_iname, 4),
 394           .d_iname = "alfa" },
 395         { .d_parent = &test_dentry[2],
 396           .d_name = QSTR_INIT(test_dentry[3].d_iname, 5),
 397           .d_iname = "romeo" },
 398 };
 399
 400 static void __init
 401 dentry(void)
 402 {
 403         test("foo", "%pd", &test_dentry[0]);
 404         test("foo", "%pd2", &test_dentry[0]);
 405
 406         test("romeo", "%pd", &test_dentry[3]);
 407         test("alfa/romeo", "%pd2", &test_dentry[3]);
 408         test("bravo/alfa/romeo", "%pd3", &test_dentry[3]);
 409         test("/bravo/alfa/romeo", "%pd4", &test_dentry[3]);
 410         test("/bravo/alfa", "%pd4", &test_dentry[2]);
 411
 412         test("bravo/alfa  |bravo/alfa  ", "%-12pd2|%*pd2", &test_dentry[2], -12, &test_dentry[2]);
 413         test("  bravo/alfa|  bravo/alfa", "%12pd2|%*pd2", &test_dentry[2], 12, &test_dentry[2]);
 414 }
 415
 416 static void __init
 417 struct_va_format(void)
 418 {
 419 }
 420
 421 static void __init
 422 struct_clk(void)
 423 {
 424 }
 425
 426 static void __init
 427 large_bitmap(void)
 428 {
 429         const int nbits = 1 << 16;
 430         unsigned long *bits = kcalloc(BITS_TO_LONGS(nbits), sizeof(long), GFP_KERNEL);
 431         if (!bits)
 432                 return;
 433
 434         bitmap_set(bits, 1, 20);
 435         bitmap_set(bits, 60000, 15);
 436         test("1-20,60000-60014", "%*pbl", nbits, bits);
 437         kfree(bits);
 438 }
 439
 440 static void __init
 441 bitmap(void)
 442 {
 443         DECLARE_BITMAP(bits, 20);
 444         const int primes[] = {2,3,5,7,11,13,17,19};
 445         int i;
 446
 447         bitmap_zero(bits, 20);
 448         test("00000|00000", "%20pb|%*pb", bits, 20, bits);
 449         test("|", "%20pbl|%*pbl", bits, 20, bits);
 450
 451         for (i = 0; i < ARRAY_SIZE(primes); ++i)
 452                 set_bit(primes[i], bits);
 453         test("a28ac|a28ac", "%20pb|%*pb", bits, 20, bits);
 454         test("2-3,5,7,11,13,17,19|2-3,5,7,11,13,17,19", "%20pbl|%*pbl", bits, 20, bits);
 455
 456         bitmap_fill(bits, 20);
 457         test("fffff|fffff", "%20pb|%*pb", bits, 20, bits);
 458         test("0-19|0-19", "%20pbl|%*pbl", bits, 20, bits);
 459
 460         large_bitmap();
 461 }
 462
 463 static void __init
 464 netdev_features(void)
 465 {
 466 }
 467
 468 static void __init
 469 flags(void)
 470 {
 471         unsigned long flags;
 472         gfp_t gfp;
 473         char *cmp_buffer;
 474
 475         flags = 0;
 476         test("", "%pGp", &flags);
 477
 478         /* Page flags should filter the zone id */
 479         flags = 1UL << NR_PAGEFLAGS;
 480         test("", "%pGp", &flags);
 481
 482         flags |= 1UL << PG_uptodate | 1UL << PG_dirty | 1UL << PG_lru
 483                 | 1UL << PG_active | 1UL << PG_swapbacked;
 484         test("uptodate|dirty|lru|active|swapbacked", "%pGp", &flags);
 485
 486
 487         flags = VM_READ | VM_EXEC | VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC
 488                         | VM_DENYWRITE;
 489         test("read|exec|mayread|maywrite|mayexec|denywrite", "%pGv", &flags);
 490
 491         gfp = GFP_TRANSHUGE;
 492         test("GFP_TRANSHUGE", "%pGg", &gfp);
 493
 494         gfp = GFP_ATOMIC|__GFP_DMA;
 495         test("GFP_ATOMIC|GFP_DMA", "%pGg", &gfp);
 496
 497         gfp = __GFP_ATOMIC;
 498         test("__GFP_ATOMIC", "%pGg", &gfp);
 499
 500         cmp_buffer = kmalloc(BUF_SIZE, GFP_KERNEL);
 501         if (!cmp_buffer)
 502                 return;
 503
 504         /* Any flags not translated by the table should remain numeric */
 505         gfp = ~__GFP_BITS_MASK;
 506         snprintf(cmp_buffer, BUF_SIZE, "%#lx", (unsigned long) gfp);
 507         test(cmp_buffer, "%pGg", &gfp);
 508
 509         snprintf(cmp_buffer, BUF_SIZE, "__GFP_ATOMIC|%#lx",
 510                                                         (unsigned long) gfp);
 511         gfp |= __GFP_ATOMIC;
 512         test(cmp_buffer, "%pGg", &gfp);
 513
 514         kfree(cmp_buffer);
 515 }
 516
 517 static void __init
 518 test_pointer(void)
 519 {
 520         plain();
 521         symbol_ptr();
 522         kernel_ptr();
 523         struct_resource();
 524         addr();
 525         escaped_str();
 526         hex_string();
 527         mac();
 528         ip();
 529         uuid();
 530         dentry();
 531         struct_va_format();
 532         struct_clk();
 533         bitmap();
 534         netdev_features();
 535         flags();
 536 }
 537
 538 static int __init
 539 test_printf_init(void)
 540 {
 541         alloced_buffer = kmalloc(BUF_SIZE + 2*PAD_SIZE, GFP_KERNEL);
 542         if (!alloced_buffer)
 543                 return -ENOMEM;
 544         test_buffer = alloced_buffer + PAD_SIZE;
 545
 546         test_basic();
 547         test_number();
 548         test_string();
 549         test_pointer();
 550
 551         kfree(alloced_buffer);
 552
 553         if (failed_tests == 0)
 554                 pr_info("all %u tests passed\n", total_tests);
 555         else
 556                 pr_warn("failed %u out of %u tests\n", failed_tests, total_tests);
 557
 558         return failed_tests ? -EINVAL : 0;
 559 }
 560
 561 module_init(test_printf_init);
 562
 563 MODULE_AUTHOR("Rasmus Villemoes <linux@rasmusvillemoes.dk>");
 564 MODULE_LICENSE("GPL");