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/rtc.h>
  13 #include <linux/slab.h>
  14 #include <linux/string.h>
  15
  16 #include <linux/bitmap.h>
  17 #include <linux/dcache.h>
  18 #include <linux/socket.h>
  19 #include <linux/in.h>
  20
  21 #include <linux/gfp.h>
  22 #include <linux/mm.h>
  23
  24 #define BUF_SIZE 256
  25 #define PAD_SIZE 16
  26 #define FILL_CHAR '$'
  27
  28 static unsigned total_tests __initdata;
  29 static unsigned failed_tests __initdata;
  30 static char *test_buffer __initdata;
  31 static char *alloced_buffer __initdata;
  32
  33 static int __printf(4, 0) __init
  34 do_test(int bufsize, const char *expect, int elen,
  35         const char *fmt, va_list ap)
  36 {
  37         va_list aq;
  38         int ret, written;
  39
  40         total_tests++;
  41
  42         memset(alloced_buffer, FILL_CHAR, BUF_SIZE + 2*PAD_SIZE);
  43         va_copy(aq, ap);
  44         ret = vsnprintf(test_buffer, bufsize, fmt, aq);
  45         va_end(aq);
  46
  47         if (ret != elen) {
  48                 pr_warn("vsnprintf(buf, %d, \"%s\", ...) returned %d, expected %d\n",
  49                         bufsize, fmt, ret, elen);
  50                 return 1;
  51         }
  52
  53         if (memchr_inv(alloced_buffer, FILL_CHAR, PAD_SIZE)) {
  54                 pr_warn("vsnprintf(buf, %d, \"%s\", ...) wrote before buffer\n", bufsize, fmt);
  55                 return 1;
  56         }
  57
  58         if (!bufsize) {
  59                 if (memchr_inv(test_buffer, FILL_CHAR, BUF_SIZE + PAD_SIZE)) {
  60                         pr_warn("vsnprintf(buf, 0, \"%s\", ...) wrote to buffer\n",
  61                                 fmt);
  62                         return 1;
  63                 }
  64                 return 0;
  65         }
  66
  67         written = min(bufsize-1, elen);
  68         if (test_buffer[written]) {
  69                 pr_warn("vsnprintf(buf, %d, \"%s\", ...) did not nul-terminate buffer\n",
  70                         bufsize, fmt);
  71                 return 1;
  72         }
  73
  74         if (memchr_inv(test_buffer + written + 1, FILL_CHAR, BUF_SIZE + PAD_SIZE - (written + 1))) {
  75                 pr_warn("vsnprintf(buf, %d, \"%s\", ...) wrote beyond the nul-terminator\n",
  76                         bufsize, fmt);
  77                 return 1;
  78         }
  79
  80         if (memcmp(test_buffer, expect, written)) {
  81                 pr_warn("vsnprintf(buf, %d, \"%s\", ...) wrote '%s', expected '%.*s'\n",
  82                         bufsize, fmt, test_buffer, written, expect);
  83                 return 1;
  84         }
  85         return 0;
  86 }
  87
  88 static void __printf(3, 4) __init
  89 __test(const char *expect, int elen, const char *fmt, ...)
  90 {
  91         va_list ap;
  92         int rand;
  93         char *p;
  94
  95         if (elen >= BUF_SIZE) {
  96                 pr_err("error in test suite: expected output length %d too long. Format was '%s'.\n",
  97                        elen, fmt);
  98                 failed_tests++;
  99                 return;
 100         }
 101
 102         va_start(ap, fmt);
 103
 104         /*
 105          * Every fmt+args is subjected to four tests: Three where we
 106          * tell vsnprintf varying buffer sizes (plenty, not quite
 107          * enough and 0), and then we also test that kvasprintf would
 108          * be able to print it as expected.
 109          */
 110         failed_tests += do_test(BUF_SIZE, expect, elen, fmt, ap);
 111         rand = 1 + prandom_u32_max(elen+1);
 112         /* Since elen < BUF_SIZE, we have 1 <= rand <= BUF_SIZE. */
 113         failed_tests += do_test(rand, expect, elen, fmt, ap);
 114         failed_tests += do_test(0, expect, elen, fmt, ap);
 115
 116         p = kvasprintf(GFP_KERNEL, fmt, ap);
 117         if (p) {
 118                 total_tests++;
 119                 if (memcmp(p, expect, elen+1)) {
 120                         pr_warn("kvasprintf(..., \"%s\", ...) returned '%s', expected '%s'\n",
 121                                 fmt, p, expect);
 122                         failed_tests++;
 123                 }
 124                 kfree(p);
 125         }
 126         va_end(ap);
 127 }
 128
 129 #define test(expect, fmt, ...)                                  \
 130         __test(expect, strlen(expect), fmt, ##__VA_ARGS__)
 131
 132 static void __init
 133 test_basic(void)
 134 {
 135         /* Work around annoying "warning: zero-length gnu_printf format string". */
 136         char nul = '\0';
 137
 138         test("", &nul);
 139         test("100%", "100%%");
 140         test("xxx%yyy", "xxx%cyyy", '%');
 141         __test("xxx\0yyy", 7, "xxx%cyyy", '\0');
 142 }
 143
 144 static void __init
 145 test_number(void)
 146 {
 147         test("0x1234abcd  ", "%#-12x", 0x1234abcd);
 148         test("  0x1234abcd", "%#12x", 0x1234abcd);
 149         test("0|001| 12|+123| 1234|-123|-1234", "%d|%03d|%3d|%+d|% d|%+d|% d", 0, 1, 12, 123, 1234, -123, -1234);
 150         test("0|1|1|128|255", "%hhu|%hhu|%hhu|%hhu|%hhu", 0, 1, 257, 128, -1);
 151         test("0|1|1|-128|-1", "%hhd|%hhd|%hhd|%hhd|%hhd", 0, 1, 257, 128, -1);
 152         test("2015122420151225", "%ho%ho%#ho", 1037, 5282, -11627);
 153         /*
 154          * POSIX/C99: »The result of converting zero with an explicit
 155          * precision of zero shall be no characters.« Hence the output
 156          * from the below test should really be "00|0||| ". However,
 157          * the kernel's printf also produces a single 0 in that
 158          * case. This test case simply documents the current
 159          * behaviour.
 160          */
 161         test("00|0|0|0|0", "%.2d|%.1d|%.0d|%.*d|%1.0d", 0, 0, 0, 0, 0, 0);
 162 #ifndef __CHAR_UNSIGNED__
 163         {
 164                 /*
 165                  * Passing a 'char' to a %02x specifier doesn't do
 166                  * what was presumably the intention when char is
 167                  * signed and the value is negative. One must either &
 168                  * with 0xff or cast to u8.
 169                  */
 170                 char val = -16;
 171                 test("0xfffffff0|0xf0|0xf0", "%#02x|%#02x|%#02x", val, val & 0xff, (u8)val);
 172         }
 173 #endif
 174 }
 175
 176 static void __init
 177 test_string(void)
 178 {
 179         test("", "%s%.0s", "", "123");
 180         test("ABCD|abc|123", "%s|%.3s|%.*s", "ABCD", "abcdef", 3, "123456");
 181         test("1  |  2|3  |  4|5  ", "%-3s|%3s|%-*s|%*s|%*s", "1", "2", 3, "3", 3, "4", -3, "5");
 182         test("1234      ", "%-10.4s", "123456");
 183         test("      1234", "%10.4s", "123456");
 184         /*
 185          * POSIX and C99 say that a negative precision (which is only
 186          * possible to pass via a * argument) should be treated as if
 187          * the precision wasn't present, and that if the precision is
 188          * omitted (as in %.s), the precision should be taken to be
 189          * 0. However, the kernel's printf behave exactly opposite,
 190          * treating a negative precision as 0 and treating an omitted
 191          * precision specifier as if no precision was given.
 192          *
 193          * These test cases document the current behaviour; should
 194          * anyone ever feel the need to follow the standards more
 195          * closely, this can be revisited.
 196          */
 197         test("    ", "%4.*s", -5, "123456");
 198         test("123456", "%.s", "123456");
 199         test("a||", "%.s|%.0s|%.*s", "a", "b", 0, "c");
 200         test("a  |   |   ", "%-3.s|%-3.0s|%-3.*s", "a", "b", 0, "c");
 201 }
 202
 203 #define PLAIN_BUF_SIZE 64       /* leave some space so we don't oops */
 204
 205 #if BITS_PER_LONG == 64
 206
 207 #define PTR_WIDTH 16
 208 #define PTR ((void *)0xffff0123456789abUL)
 209 #define PTR_STR "ffff0123456789ab"
 210 #define PTR_VAL_NO_CRNG "(____ptrval____)"
 211 #define ZEROS "00000000"        /* hex 32 zero bits */
 212
 213 static int __init
 214 plain_format(void)
 215 {
 216         char buf[PLAIN_BUF_SIZE];
 217         int nchars;
 218
 219         nchars = snprintf(buf, PLAIN_BUF_SIZE, "%p", PTR);
 220
 221         if (nchars != PTR_WIDTH)
 222                 return -1;
 223
 224         if (strncmp(buf, PTR_VAL_NO_CRNG, PTR_WIDTH) == 0) {
 225                 pr_warn("crng possibly not yet initialized. plain 'p' buffer contains \"%s\"",
 226                         PTR_VAL_NO_CRNG);
 227                 return 0;
 228         }
 229
 230         if (strncmp(buf, ZEROS, strlen(ZEROS)) != 0)
 231                 return -1;
 232
 233         return 0;
 234 }
 235
 236 #else
 237
 238 #define PTR_WIDTH 8
 239 #define PTR ((void *)0x456789ab)
 240 #define PTR_STR "456789ab"
 241 #define PTR_VAL_NO_CRNG "(ptrval)"
 242
 243 static int __init
 244 plain_format(void)
 245 {
 246         /* Format is implicitly tested for 32 bit machines by plain_hash() */
 247         return 0;
 248 }
 249
 250 #endif  /* BITS_PER_LONG == 64 */
 251
 252 static int __init
 253 plain_hash_to_buffer(const void *p, char *buf, size_t len)
 254 {
 255         int nchars;
 256
 257         nchars = snprintf(buf, len, "%p", p);
 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         return 0;
 269 }
 270
 271
 272 static int __init
 273 plain_hash(void)
 274 {
 275         char buf[PLAIN_BUF_SIZE];
 276         int ret;
 277
 278         ret = plain_hash_to_buffer(PTR, buf, PLAIN_BUF_SIZE);
 279         if (ret)
 280                 return ret;
 281
 282         if (strncmp(buf, PTR_STR, PTR_WIDTH) == 0)
 283                 return -1;
 284
 285         return 0;
 286 }
 287
 288 /*
 289  * We can't use test() to test %p because we don't know what output to expect
 290  * after an address is hashed.
 291  */
 292 static void __init
 293 plain(void)
 294 {
 295         int err;
 296
 297         err = plain_hash();
 298         if (err) {
 299                 pr_warn("plain 'p' does not appear to be hashed\n");
 300                 failed_tests++;
 301                 return;
 302         }
 303
 304         err = plain_format();
 305         if (err) {
 306                 pr_warn("hashing plain 'p' has unexpected format\n");
 307                 failed_tests++;
 308         }
 309 }
 310
 311 static void __init
 312 test_hashed(const char *fmt, const void *p)
 313 {
 314         char buf[PLAIN_BUF_SIZE];
 315         int ret;
 316
 317         /*
 318          * No need to increase failed test counter since this is assumed
 319          * to be called after plain().
 320          */
 321         ret = plain_hash_to_buffer(p, buf, PLAIN_BUF_SIZE);
 322         if (ret)
 323                 return;
 324
 325         test(buf, fmt, p);
 326 }
 327
 328 static void __init
 329 symbol_ptr(void)
 330 {
 331 }
 332
 333 static void __init
 334 kernel_ptr(void)
 335 {
 336         /* We can't test this without access to kptr_restrict. */
 337 }
 338
 339 static void __init
 340 struct_resource(void)
 341 {
 342 }
 343
 344 static void __init
 345 addr(void)
 346 {
 347 }
 348
 349 static void __init
 350 escaped_str(void)
 351 {
 352 }
 353
 354 static void __init
 355 hex_string(void)
 356 {
 357         const char buf[3] = {0xc0, 0xff, 0xee};
 358
 359         test("c0 ff ee|c0:ff:ee|c0-ff-ee|c0ffee",
 360              "%3ph|%3phC|%3phD|%3phN", buf, buf, buf, buf);
 361         test("c0 ff ee|c0:ff:ee|c0-ff-ee|c0ffee",
 362              "%*ph|%*phC|%*phD|%*phN", 3, buf, 3, buf, 3, buf, 3, buf);
 363 }
 364
 365 static void __init
 366 mac(void)
 367 {
 368         const u8 addr[6] = {0x2d, 0x48, 0xd6, 0xfc, 0x7a, 0x05};
 369
 370         test("2d:48:d6:fc:7a:05", "%pM", addr);
 371         test("05:7a:fc:d6:48:2d", "%pMR", addr);
 372         test("2d-48-d6-fc-7a-05", "%pMF", addr);
 373         test("2d48d6fc7a05", "%pm", addr);
 374         test("057afcd6482d", "%pmR", addr);
 375 }
 376
 377 static void __init
 378 ip4(void)
 379 {
 380         struct sockaddr_in sa;
 381
 382         sa.sin_family = AF_INET;
 383         sa.sin_port = cpu_to_be16(12345);
 384         sa.sin_addr.s_addr = cpu_to_be32(0x7f000001);
 385
 386         test("127.000.000.001|127.0.0.1", "%pi4|%pI4", &sa.sin_addr, &sa.sin_addr);
 387         test("127.000.000.001|127.0.0.1", "%piS|%pIS", &sa, &sa);
 388         sa.sin_addr.s_addr = cpu_to_be32(0x01020304);
 389         test("001.002.003.004:12345|1.2.3.4:12345", "%piSp|%pISp", &sa, &sa);
 390 }
 391
 392 static void __init
 393 ip6(void)
 394 {
 395 }
 396
 397 static void __init
 398 ip(void)
 399 {
 400         ip4();
 401         ip6();
 402 }
 403
 404 static void __init
 405 uuid(void)
 406 {
 407         const char uuid[16] = {0x0, 0x1, 0x2, 0x3, 0x4, 0x5, 0x6, 0x7,
 408                                0x8, 0x9, 0xa, 0xb, 0xc, 0xd, 0xe, 0xf};
 409
 410         test("00010203-0405-0607-0809-0a0b0c0d0e0f", "%pUb", uuid);
 411         test("00010203-0405-0607-0809-0A0B0C0D0E0F", "%pUB", uuid);
 412         test("03020100-0504-0706-0809-0a0b0c0d0e0f", "%pUl", uuid);
 413         test("03020100-0504-0706-0809-0A0B0C0D0E0F", "%pUL", uuid);
 414 }
 415
 416 static struct dentry test_dentry[4] __initdata = {
 417         { .d_parent = &test_dentry[0],
 418           .d_name = QSTR_INIT(test_dentry[0].d_iname, 3),
 419           .d_iname = "foo" },
 420         { .d_parent = &test_dentry[0],
 421           .d_name = QSTR_INIT(test_dentry[1].d_iname, 5),
 422           .d_iname = "bravo" },
 423         { .d_parent = &test_dentry[1],
 424           .d_name = QSTR_INIT(test_dentry[2].d_iname, 4),
 425           .d_iname = "alfa" },
 426         { .d_parent = &test_dentry[2],
 427           .d_name = QSTR_INIT(test_dentry[3].d_iname, 5),
 428           .d_iname = "romeo" },
 429 };
 430
 431 static void __init
 432 dentry(void)
 433 {
 434         test("foo", "%pd", &test_dentry[0]);
 435         test("foo", "%pd2", &test_dentry[0]);
 436
 437         test("romeo", "%pd", &test_dentry[3]);
 438         test("alfa/romeo", "%pd2", &test_dentry[3]);
 439         test("bravo/alfa/romeo", "%pd3", &test_dentry[3]);
 440         test("/bravo/alfa/romeo", "%pd4", &test_dentry[3]);
 441         test("/bravo/alfa", "%pd4", &test_dentry[2]);
 442
 443         test("bravo/alfa  |bravo/alfa  ", "%-12pd2|%*pd2", &test_dentry[2], -12, &test_dentry[2]);
 444         test("  bravo/alfa|  bravo/alfa", "%12pd2|%*pd2", &test_dentry[2], 12, &test_dentry[2]);
 445 }
 446
 447 static void __init
 448 struct_va_format(void)
 449 {
 450 }
 451
 452 static void __init
 453 struct_rtc_time(void)
 454 {
 455         /* 1543210543 */
 456         const struct rtc_time tm = {
 457                 .tm_sec = 43,
 458                 .tm_min = 35,
 459                 .tm_hour = 5,
 460                 .tm_mday = 26,
 461                 .tm_mon = 10,
 462                 .tm_year = 118,
 463         };
 464
 465         test_hashed("%pt", &tm);
 466
 467         test("2018-11-26T05:35:43", "%ptR", &tm);
 468         test("0118-10-26T05:35:43", "%ptRr", &tm);
 469         test("05:35:43|2018-11-26", "%ptRt|%ptRd", &tm, &tm);
 470         test("05:35:43|0118-10-26", "%ptRtr|%ptRdr", &tm, &tm);
 471         test("05:35:43|2018-11-26", "%ptRttr|%ptRdtr", &tm, &tm);
 472         test("05:35:43 tr|2018-11-26 tr", "%ptRt tr|%ptRd tr", &tm, &tm);
 473 }
 474
 475 static void __init
 476 struct_clk(void)
 477 {
 478 }
 479
 480 static void __init
 481 large_bitmap(void)
 482 {
 483         const int nbits = 1 << 16;
 484         unsigned long *bits = kcalloc(BITS_TO_LONGS(nbits), sizeof(long), GFP_KERNEL);
 485         if (!bits)
 486                 return;
 487
 488         bitmap_set(bits, 1, 20);
 489         bitmap_set(bits, 60000, 15);
 490         test("1-20,60000-60014", "%*pbl", nbits, bits);
 491         kfree(bits);
 492 }
 493
 494 static void __init
 495 bitmap(void)
 496 {
 497         DECLARE_BITMAP(bits, 20);
 498         const int primes[] = {2,3,5,7,11,13,17,19};
 499         int i;
 500
 501         bitmap_zero(bits, 20);
 502         test("00000|00000", "%20pb|%*pb", bits, 20, bits);
 503         test("|", "%20pbl|%*pbl", bits, 20, bits);
 504
 505         for (i = 0; i < ARRAY_SIZE(primes); ++i)
 506                 set_bit(primes[i], bits);
 507         test("a28ac|a28ac", "%20pb|%*pb", bits, 20, bits);
 508         test("2-3,5,7,11,13,17,19|2-3,5,7,11,13,17,19", "%20pbl|%*pbl", bits, 20, bits);
 509
 510         bitmap_fill(bits, 20);
 511         test("fffff|fffff", "%20pb|%*pb", bits, 20, bits);
 512         test("0-19|0-19", "%20pbl|%*pbl", bits, 20, bits);
 513
 514         large_bitmap();
 515 }
 516
 517 static void __init
 518 netdev_features(void)
 519 {
 520 }
 521
 522 static void __init
 523 flags(void)
 524 {
 525         unsigned long flags;
 526         gfp_t gfp;
 527         char *cmp_buffer;
 528
 529         flags = 0;
 530         test("", "%pGp", &flags);
 531
 532         /* Page flags should filter the zone id */
 533         flags = 1UL << NR_PAGEFLAGS;
 534         test("", "%pGp", &flags);
 535
 536         flags |= 1UL << PG_uptodate | 1UL << PG_dirty | 1UL << PG_lru
 537                 | 1UL << PG_active | 1UL << PG_swapbacked;
 538         test("uptodate|dirty|lru|active|swapbacked", "%pGp", &flags);
 539
 540
 541         flags = VM_READ | VM_EXEC | VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC
 542                         | VM_DENYWRITE;
 543         test("read|exec|mayread|maywrite|mayexec|denywrite", "%pGv", &flags);
 544
 545         gfp = GFP_TRANSHUGE;
 546         test("GFP_TRANSHUGE", "%pGg", &gfp);
 547
 548         gfp = GFP_ATOMIC|__GFP_DMA;
 549         test("GFP_ATOMIC|GFP_DMA", "%pGg", &gfp);
 550
 551         gfp = __GFP_ATOMIC;
 552         test("__GFP_ATOMIC", "%pGg", &gfp);
 553
 554         cmp_buffer = kmalloc(BUF_SIZE, GFP_KERNEL);
 555         if (!cmp_buffer)
 556                 return;
 557
 558         /* Any flags not translated by the table should remain numeric */
 559         gfp = ~__GFP_BITS_MASK;
 560         snprintf(cmp_buffer, BUF_SIZE, "%#lx", (unsigned long) gfp);
 561         test(cmp_buffer, "%pGg", &gfp);
 562
 563         snprintf(cmp_buffer, BUF_SIZE, "__GFP_ATOMIC|%#lx",
 564                                                         (unsigned long) gfp);
 565         gfp |= __GFP_ATOMIC;
 566         test(cmp_buffer, "%pGg", &gfp);
 567
 568         kfree(cmp_buffer);
 569 }
 570
 571 static void __init
 572 test_pointer(void)
 573 {
 574         plain();
 575         symbol_ptr();
 576         kernel_ptr();
 577         struct_resource();
 578         addr();
 579         escaped_str();
 580         hex_string();
 581         mac();
 582         ip();
 583         uuid();
 584         dentry();
 585         struct_va_format();
 586         struct_rtc_time();
 587         struct_clk();
 588         bitmap();
 589         netdev_features();
 590         flags();
 591 }
 592
 593 static int __init
 594 test_printf_init(void)
 595 {
 596         alloced_buffer = kmalloc(BUF_SIZE + 2*PAD_SIZE, GFP_KERNEL);
 597         if (!alloced_buffer)
 598                 return -ENOMEM;
 599         test_buffer = alloced_buffer + PAD_SIZE;
 600
 601         test_basic();
 602         test_number();
 603         test_string();
 604         test_pointer();
 605
 606         kfree(alloced_buffer);
 607
 608         if (failed_tests == 0)
 609                 pr_info("all %u tests passed\n", total_tests);
 610         else
 611                 pr_warn("failed %u out of %u tests\n", failed_tests, total_tests);
 612
 613         return failed_tests ? -EINVAL : 0;
 614 }
 615
 616 module_init(test_printf_init);
 617
 618 MODULE_AUTHOR("Rasmus Villemoes <linux@rasmusvillemoes.dk>");
 619 MODULE_LICENSE("GPL");