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"); 620