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"); 545