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 *)0xffff0123456789ab)
 208 #define PTR_STR "ffff0123456789ab"
 209 #define ZEROS "00000000"        /* hex 32 zero bits */
 210
 211 static int __init
 212 plain_format(void)
 213 {
 214         char buf[PLAIN_BUF_SIZE];
 215         int nchars;
 216
 217         nchars = snprintf(buf, PLAIN_BUF_SIZE, "%p", PTR);
 218
 219         if (nchars != PTR_WIDTH || strncmp(buf, ZEROS, strlen(ZEROS)) != 0)
 220                 return -1;
 221
 222         return 0;
 223 }
 224
 225 #else
 226
 227 #define PTR_WIDTH 8
 228 #define PTR ((void *)0x456789ab)
 229 #define PTR_STR "456789ab"
 230
 231 static int __init
 232 plain_format(void)
 233 {
 234         /* Format is implicitly tested for 32 bit machines by plain_hash() */
 235         return 0;
 236 }
 237
 238 #endif  /* BITS_PER_LONG == 64 */
 239
 240 static int __init
 241 plain_hash(void)
 242 {
 243         char buf[PLAIN_BUF_SIZE];
 244         int nchars;
 245
 246         nchars = snprintf(buf, PLAIN_BUF_SIZE, "%p", PTR);
 247
 248         if (nchars != PTR_WIDTH || strncmp(buf, PTR_STR, PTR_WIDTH) == 0)
 249                 return -1;
 250
 251         return 0;
 252 }
 253
 254 /*
 255  * We can't use test() to test %p because we don't know what output to expect
 256  * after an address is hashed.
 257  */
 258 static void __init
 259 plain(void)
 260 {
 261         int err;
 262
 263         err = plain_hash();
 264         if (err) {
 265                 pr_warn("plain 'p' does not appear to be hashed\n");
 266                 failed_tests++;
 267                 return;
 268         }
 269
 270         err = plain_format();
 271         if (err) {
 272                 pr_warn("hashing plain 'p' has unexpected format\n");
 273                 failed_tests++;
 274         }
 275 }
 276
 277 static void __init
 278 symbol_ptr(void)
 279 {
 280 }
 281
 282 static void __init
 283 kernel_ptr(void)
 284 {
 285         /* We can't test this without access to kptr_restrict. */
 286 }
 287
 288 static void __init
 289 struct_resource(void)
 290 {
 291 }
 292
 293 static void __init
 294 addr(void)
 295 {
 296 }
 297
 298 static void __init
 299 escaped_str(void)
 300 {
 301 }
 302
 303 static void __init
 304 hex_string(void)
 305 {
 306         const char buf[3] = {0xc0, 0xff, 0xee};
 307
 308         test("c0 ff ee|c0:ff:ee|c0-ff-ee|c0ffee",
 309              "%3ph|%3phC|%3phD|%3phN", buf, buf, buf, buf);
 310         test("c0 ff ee|c0:ff:ee|c0-ff-ee|c0ffee",
 311              "%*ph|%*phC|%*phD|%*phN", 3, buf, 3, buf, 3, buf, 3, buf);
 312 }
 313
 314 static void __init
 315 mac(void)
 316 {
 317         const u8 addr[6] = {0x2d, 0x48, 0xd6, 0xfc, 0x7a, 0x05};
 318
 319         test("2d:48:d6:fc:7a:05", "%pM", addr);
 320         test("05:7a:fc:d6:48:2d", "%pMR", addr);
 321         test("2d-48-d6-fc-7a-05", "%pMF", addr);
 322         test("2d48d6fc7a05", "%pm", addr);
 323         test("057afcd6482d", "%pmR", addr);
 324 }
 325
 326 static void __init
 327 ip4(void)
 328 {
 329         struct sockaddr_in sa;
 330
 331         sa.sin_family = AF_INET;
 332         sa.sin_port = cpu_to_be16(12345);
 333         sa.sin_addr.s_addr = cpu_to_be32(0x7f000001);
 334
 335         test("127.000.000.001|127.0.0.1", "%pi4|%pI4", &sa.sin_addr, &sa.sin_addr);
 336         test("127.000.000.001|127.0.0.1", "%piS|%pIS", &sa, &sa);
 337         sa.sin_addr.s_addr = cpu_to_be32(0x01020304);
 338         test("001.002.003.004:12345|1.2.3.4:12345", "%piSp|%pISp", &sa, &sa);
 339 }
 340
 341 static void __init
 342 ip6(void)
 343 {
 344 }
 345
 346 static void __init
 347 ip(void)
 348 {
 349         ip4();
 350         ip6();
 351 }
 352
 353 static void __init
 354 uuid(void)
 355 {
 356         const char uuid[16] = {0x0, 0x1, 0x2, 0x3, 0x4, 0x5, 0x6, 0x7,
 357                                0x8, 0x9, 0xa, 0xb, 0xc, 0xd, 0xe, 0xf};
 358
 359         test("00010203-0405-0607-0809-0a0b0c0d0e0f", "%pUb", uuid);
 360         test("00010203-0405-0607-0809-0A0B0C0D0E0F", "%pUB", uuid);
 361         test("03020100-0504-0706-0809-0a0b0c0d0e0f", "%pUl", uuid);
 362         test("03020100-0504-0706-0809-0A0B0C0D0E0F", "%pUL", uuid);
 363 }
 364
 365 static struct dentry test_dentry[4] __initdata = {
 366         { .d_parent = &test_dentry[0],
 367           .d_name = QSTR_INIT(test_dentry[0].d_iname, 3),
 368           .d_iname = "foo" },
 369         { .d_parent = &test_dentry[0],
 370           .d_name = QSTR_INIT(test_dentry[1].d_iname, 5),
 371           .d_iname = "bravo" },
 372         { .d_parent = &test_dentry[1],
 373           .d_name = QSTR_INIT(test_dentry[2].d_iname, 4),
 374           .d_iname = "alfa" },
 375         { .d_parent = &test_dentry[2],
 376           .d_name = QSTR_INIT(test_dentry[3].d_iname, 5),
 377           .d_iname = "romeo" },
 378 };
 379
 380 static void __init
 381 dentry(void)
 382 {
 383         test("foo", "%pd", &test_dentry[0]);
 384         test("foo", "%pd2", &test_dentry[0]);
 385
 386         test("romeo", "%pd", &test_dentry[3]);
 387         test("alfa/romeo", "%pd2", &test_dentry[3]);
 388         test("bravo/alfa/romeo", "%pd3", &test_dentry[3]);
 389         test("/bravo/alfa/romeo", "%pd4", &test_dentry[3]);
 390         test("/bravo/alfa", "%pd4", &test_dentry[2]);
 391
 392         test("bravo/alfa  |bravo/alfa  ", "%-12pd2|%*pd2", &test_dentry[2], -12, &test_dentry[2]);
 393         test("  bravo/alfa|  bravo/alfa", "%12pd2|%*pd2", &test_dentry[2], 12, &test_dentry[2]);
 394 }
 395
 396 static void __init
 397 struct_va_format(void)
 398 {
 399 }
 400
 401 static void __init
 402 struct_clk(void)
 403 {
 404 }
 405
 406 static void __init
 407 large_bitmap(void)
 408 {
 409         const int nbits = 1 << 16;
 410         unsigned long *bits = kcalloc(BITS_TO_LONGS(nbits), sizeof(long), GFP_KERNEL);
 411         if (!bits)
 412                 return;
 413
 414         bitmap_set(bits, 1, 20);
 415         bitmap_set(bits, 60000, 15);
 416         test("1-20,60000-60014", "%*pbl", nbits, bits);
 417         kfree(bits);
 418 }
 419
 420 static void __init
 421 bitmap(void)
 422 {
 423         DECLARE_BITMAP(bits, 20);
 424         const int primes[] = {2,3,5,7,11,13,17,19};
 425         int i;
 426
 427         bitmap_zero(bits, 20);
 428         test("00000|00000", "%20pb|%*pb", bits, 20, bits);
 429         test("|", "%20pbl|%*pbl", bits, 20, bits);
 430
 431         for (i = 0; i < ARRAY_SIZE(primes); ++i)
 432                 set_bit(primes[i], bits);
 433         test("a28ac|a28ac", "%20pb|%*pb", bits, 20, bits);
 434         test("2-3,5,7,11,13,17,19|2-3,5,7,11,13,17,19", "%20pbl|%*pbl", bits, 20, bits);
 435
 436         bitmap_fill(bits, 20);
 437         test("fffff|fffff", "%20pb|%*pb", bits, 20, bits);
 438         test("0-19|0-19", "%20pbl|%*pbl", bits, 20, bits);
 439
 440         large_bitmap();
 441 }
 442
 443 static void __init
 444 netdev_features(void)
 445 {
 446 }
 447
 448 static void __init
 449 flags(void)
 450 {
 451         unsigned long flags;
 452         gfp_t gfp;
 453         char *cmp_buffer;
 454
 455         flags = 0;
 456         test("", "%pGp", &flags);
 457
 458         /* Page flags should filter the zone id */
 459         flags = 1UL << NR_PAGEFLAGS;
 460         test("", "%pGp", &flags);
 461
 462         flags |= 1UL << PG_uptodate | 1UL << PG_dirty | 1UL << PG_lru
 463                 | 1UL << PG_active | 1UL << PG_swapbacked;
 464         test("uptodate|dirty|lru|active|swapbacked", "%pGp", &flags);
 465
 466
 467         flags = VM_READ | VM_EXEC | VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC
 468                         | VM_DENYWRITE;
 469         test("read|exec|mayread|maywrite|mayexec|denywrite", "%pGv", &flags);
 470
 471         gfp = GFP_TRANSHUGE;
 472         test("GFP_TRANSHUGE", "%pGg", &gfp);
 473
 474         gfp = GFP_ATOMIC|__GFP_DMA;
 475         test("GFP_ATOMIC|GFP_DMA", "%pGg", &gfp);
 476
 477         gfp = __GFP_ATOMIC;
 478         test("__GFP_ATOMIC", "%pGg", &gfp);
 479
 480         cmp_buffer = kmalloc(BUF_SIZE, GFP_KERNEL);
 481         if (!cmp_buffer)
 482                 return;
 483
 484         /* Any flags not translated by the table should remain numeric */
 485         gfp = ~__GFP_BITS_MASK;
 486         snprintf(cmp_buffer, BUF_SIZE, "%#lx", (unsigned long) gfp);
 487         test(cmp_buffer, "%pGg", &gfp);
 488
 489         snprintf(cmp_buffer, BUF_SIZE, "__GFP_ATOMIC|%#lx",
 490                                                         (unsigned long) gfp);
 491         gfp |= __GFP_ATOMIC;
 492         test(cmp_buffer, "%pGg", &gfp);
 493
 494         kfree(cmp_buffer);
 495 }
 496
 497 static void __init
 498 test_pointer(void)
 499 {
 500         plain();
 501         symbol_ptr();
 502         kernel_ptr();
 503         struct_resource();
 504         addr();
 505         escaped_str();
 506         hex_string();
 507         mac();
 508         ip();
 509         uuid();
 510         dentry();
 511         struct_va_format();
 512         struct_clk();
 513         bitmap();
 514         netdev_features();
 515         flags();
 516 }
 517
 518 static int __init
 519 test_printf_init(void)
 520 {
 521         alloced_buffer = kmalloc(BUF_SIZE + 2*PAD_SIZE, GFP_KERNEL);
 522         if (!alloced_buffer)
 523                 return -ENOMEM;
 524         test_buffer = alloced_buffer + PAD_SIZE;
 525
 526         test_basic();
 527         test_number();
 528         test_string();
 529         test_pointer();
 530
 531         kfree(alloced_buffer);
 532
 533         if (failed_tests == 0)
 534                 pr_info("all %u tests passed\n", total_tests);
 535         else
 536                 pr_warn("failed %u out of %u tests\n", failed_tests, total_tests);
 537
 538         return failed_tests ? -EINVAL : 0;
 539 }
 540
 541 module_init(test_printf_init);
 542
 543 MODULE_AUTHOR("Rasmus Villemoes <linux@rasmusvillemoes.dk>");
 544 MODULE_LICENSE("GPL");