lib/test_printf.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Test cases for printf facility.
   4  */
   5
   6 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
   7
   8 #include <linux/init.h>
   9 #include <linux/kernel.h>
  10 #include <linux/module.h>
  11 #include <linux/printk.h>
  12 #include <linux/random.h>
  13 #include <linux/rtc.h>
  14 #include <linux/slab.h>
  15 #include <linux/string.h>
  16
  17 #include <linux/bitmap.h>
  18 #include <linux/dcache.h>
  19 #include <linux/socket.h>
  20 #include <linux/in.h>
  21
  22 #include <linux/gfp.h>
  23 #include <linux/mm.h>
  24
  25 #include "../tools/testing/selftests/kselftest_module.h"
  26
  27 #define BUF_SIZE 256
  28 #define PAD_SIZE 16
  29 #define FILL_CHAR '$'
  30
  31 static unsigned total_tests __initdata;
  32 static unsigned failed_tests __initdata;
  33 static char *test_buffer __initdata;
  34 static char *alloced_buffer __initdata;
  35
  36 static int __printf(4, 0) __init
  37 do_test(int bufsize, const char *expect, int elen,
  38         const char *fmt, va_list ap)
  39 {
  40         va_list aq;
  41         int ret, written;
  42
  43         total_tests++;
  44
  45         memset(alloced_buffer, FILL_CHAR, BUF_SIZE + 2*PAD_SIZE);
  46         va_copy(aq, ap);
  47         ret = vsnprintf(test_buffer, bufsize, fmt, aq);
  48         va_end(aq);
  49
  50         if (ret != elen) {
  51                 pr_warn("vsnprintf(buf, %d, \"%s\", ...) returned %d, expected %d\n",
  52                         bufsize, fmt, ret, elen);
  53                 return 1;
  54         }
  55
  56         if (memchr_inv(alloced_buffer, FILL_CHAR, PAD_SIZE)) {
  57                 pr_warn("vsnprintf(buf, %d, \"%s\", ...) wrote before buffer\n", bufsize, fmt);
  58                 return 1;
  59         }
  60
  61         if (!bufsize) {
  62                 if (memchr_inv(test_buffer, FILL_CHAR, BUF_SIZE + PAD_SIZE)) {
  63                         pr_warn("vsnprintf(buf, 0, \"%s\", ...) wrote to buffer\n",
  64                                 fmt);
  65                         return 1;
  66                 }
  67                 return 0;
  68         }
  69
  70         written = min(bufsize-1, elen);
  71         if (test_buffer[written]) {
  72                 pr_warn("vsnprintf(buf, %d, \"%s\", ...) did not nul-terminate buffer\n",
  73                         bufsize, fmt);
  74                 return 1;
  75         }
  76
  77         if (memchr_inv(test_buffer + written + 1, FILL_CHAR, BUF_SIZE + PAD_SIZE - (written + 1))) {
  78                 pr_warn("vsnprintf(buf, %d, \"%s\", ...) wrote beyond the nul-terminator\n",
  79                         bufsize, fmt);
  80                 return 1;
  81         }
  82
  83         if (memcmp(test_buffer, expect, written)) {
  84                 pr_warn("vsnprintf(buf, %d, \"%s\", ...) wrote '%s', expected '%.*s'\n",
  85                         bufsize, fmt, test_buffer, written, expect);
  86                 return 1;
  87         }
  88         return 0;
  89 }
  90
  91 static void __printf(3, 4) __init
  92 __test(const char *expect, int elen, const char *fmt, ...)
  93 {
  94         va_list ap;
  95         int rand;
  96         char *p;
  97
  98         if (elen >= BUF_SIZE) {
  99                 pr_err("error in test suite: expected output length %d too long. Format was '%s'.\n",
 100                        elen, fmt);
 101                 failed_tests++;
 102                 return;
 103         }
 104
 105         va_start(ap, fmt);
 106
 107         /*
 108          * Every fmt+args is subjected to four tests: Three where we
 109          * tell vsnprintf varying buffer sizes (plenty, not quite
 110          * enough and 0), and then we also test that kvasprintf would
 111          * be able to print it as expected.
 112          */
 113         failed_tests += do_test(BUF_SIZE, expect, elen, fmt, ap);
 114         rand = 1 + prandom_u32_max(elen+1);
 115         /* Since elen < BUF_SIZE, we have 1 <= rand <= BUF_SIZE. */
 116         failed_tests += do_test(rand, expect, elen, fmt, ap);
 117         failed_tests += do_test(0, expect, elen, fmt, ap);
 118
 119         p = kvasprintf(GFP_KERNEL, fmt, ap);
 120         if (p) {
 121                 total_tests++;
 122                 if (memcmp(p, expect, elen+1)) {
 123                         pr_warn("kvasprintf(..., \"%s\", ...) returned '%s', expected '%s'\n",
 124                                 fmt, p, expect);
 125                         failed_tests++;
 126                 }
 127                 kfree(p);
 128         }
 129         va_end(ap);
 130 }
 131
 132 #define test(expect, fmt, ...)                                  \
 133         __test(expect, strlen(expect), fmt, ##__VA_ARGS__)
 134
 135 static void __init
 136 test_basic(void)
 137 {
 138         /* Work around annoying "warning: zero-length gnu_printf format string". */
 139         char nul = '\0';
 140
 141         test("", &nul);
 142         test("100%", "100%%");
 143         test("xxx%yyy", "xxx%cyyy", '%');
 144         __test("xxx\0yyy", 7, "xxx%cyyy", '\0');
 145 }
 146
 147 static void __init
 148 test_number(void)
 149 {
 150         test("0x1234abcd  ", "%#-12x", 0x1234abcd);
 151         test("  0x1234abcd", "%#12x", 0x1234abcd);
 152         test("0|001| 12|+123| 1234|-123|-1234", "%d|%03d|%3d|%+d|% d|%+d|% d", 0, 1, 12, 123, 1234, -123, -1234);
 153         test("0|1|1|128|255", "%hhu|%hhu|%hhu|%hhu|%hhu", 0, 1, 257, 128, -1);
 154         test("0|1|1|-128|-1", "%hhd|%hhd|%hhd|%hhd|%hhd", 0, 1, 257, 128, -1);
 155         test("2015122420151225", "%ho%ho%#ho", 1037, 5282, -11627);
 156         /*
 157          * POSIX/C99: »The result of converting zero with an explicit
 158          * precision of zero shall be no characters.« Hence the output
 159          * from the below test should really be "00|0||| ". However,
 160          * the kernel's printf also produces a single 0 in that
 161          * case. This test case simply documents the current
 162          * behaviour.
 163          */
 164         test("00|0|0|0|0", "%.2d|%.1d|%.0d|%.*d|%1.0d", 0, 0, 0, 0, 0, 0);
 165 #ifndef __CHAR_UNSIGNED__
 166         {
 167                 /*
 168                  * Passing a 'char' to a %02x specifier doesn't do
 169                  * what was presumably the intention when char is
 170                  * signed and the value is negative. One must either &
 171                  * with 0xff or cast to u8.
 172                  */
 173                 char val = -16;
 174                 test("0xfffffff0|0xf0|0xf0", "%#02x|%#02x|%#02x", val, val & 0xff, (u8)val);
 175         }
 176 #endif
 177 }
 178
 179 static void __init
 180 test_string(void)
 181 {
 182         test("", "%s%.0s", "", "123");
 183         test("ABCD|abc|123", "%s|%.3s|%.*s", "ABCD", "abcdef", 3, "123456");
 184         test("1  |  2|3  |  4|5  ", "%-3s|%3s|%-*s|%*s|%*s", "1", "2", 3, "3", 3, "4", -3, "5");
 185         test("1234      ", "%-10.4s", "123456");
 186         test("      1234", "%10.4s", "123456");
 187         /*
 188          * POSIX and C99 say that a negative precision (which is only
 189          * possible to pass via a * argument) should be treated as if
 190          * the precision wasn't present, and that if the precision is
 191          * omitted (as in %.s), the precision should be taken to be
 192          * 0. However, the kernel's printf behave exactly opposite,
 193          * treating a negative precision as 0 and treating an omitted
 194          * precision specifier as if no precision was given.
 195          *
 196          * These test cases document the current behaviour; should
 197          * anyone ever feel the need to follow the standards more
 198          * closely, this can be revisited.
 199          */
 200         test("    ", "%4.*s", -5, "123456");
 201         test("123456", "%.s", "123456");
 202         test("a||", "%.s|%.0s|%.*s", "a", "b", 0, "c");
 203         test("a  |   |   ", "%-3.s|%-3.0s|%-3.*s", "a", "b", 0, "c");
 204 }
 205
 206 #define PLAIN_BUF_SIZE 64       /* leave some space so we don't oops */
 207
 208 #if BITS_PER_LONG == 64
 209
 210 #define PTR_WIDTH 16
 211 #define PTR ((void *)0xffff0123456789abUL)
 212 #define PTR_STR "ffff0123456789ab"
 213 #define PTR_VAL_NO_CRNG "(____ptrval____)"
 214 #define ZEROS "00000000"        /* hex 32 zero bits */
 215
 216 static int __init
 217 plain_format(void)
 218 {
 219         char buf[PLAIN_BUF_SIZE];
 220         int nchars;
 221
 222         nchars = snprintf(buf, PLAIN_BUF_SIZE, "%p", PTR);
 223
 224         if (nchars != PTR_WIDTH)
 225                 return -1;
 226
 227         if (strncmp(buf, PTR_VAL_NO_CRNG, PTR_WIDTH) == 0) {
 228                 pr_warn("crng possibly not yet initialized. plain 'p' buffer contains \"%s\"",
 229                         PTR_VAL_NO_CRNG);
 230                 return 0;
 231         }
 232
 233         if (strncmp(buf, ZEROS, strlen(ZEROS)) != 0)
 234                 return -1;
 235
 236         return 0;
 237 }
 238
 239 #else
 240
 241 #define PTR_WIDTH 8
 242 #define PTR ((void *)0x456789ab)
 243 #define PTR_STR "456789ab"
 244 #define PTR_VAL_NO_CRNG "(ptrval)"
 245 #define ZEROS ""
 246
 247 static int __init
 248 plain_format(void)
 249 {
 250         /* Format is implicitly tested for 32 bit machines by plain_hash() */
 251         return 0;
 252 }
 253
 254 #endif  /* BITS_PER_LONG == 64 */
 255
 256 static int __init
 257 plain_hash_to_buffer(const void *p, char *buf, size_t len)
 258 {
 259         int nchars;
 260
 261         nchars = snprintf(buf, len, "%p", p);
 262
 263         if (nchars != PTR_WIDTH)
 264                 return -1;
 265
 266         if (strncmp(buf, PTR_VAL_NO_CRNG, PTR_WIDTH) == 0) {
 267                 pr_warn("crng possibly not yet initialized. plain 'p' buffer contains \"%s\"",
 268                         PTR_VAL_NO_CRNG);
 269                 return 0;
 270         }
 271
 272         return 0;
 273 }
 274
 275 static int __init
 276 plain_hash(void)
 277 {
 278         char buf[PLAIN_BUF_SIZE];
 279         int ret;
 280
 281         ret = plain_hash_to_buffer(PTR, buf, PLAIN_BUF_SIZE);
 282         if (ret)
 283                 return ret;
 284
 285         if (strncmp(buf, PTR_STR, PTR_WIDTH) == 0)
 286                 return -1;
 287
 288         return 0;
 289 }
 290
 291 /*
 292  * We can't use test() to test %p because we don't know what output to expect
 293  * after an address is hashed.
 294  */
 295 static void __init
 296 plain(void)
 297 {
 298         int err;
 299
 300         err = plain_hash();
 301         if (err) {
 302                 pr_warn("plain 'p' does not appear to be hashed\n");
 303                 failed_tests++;
 304                 return;
 305         }
 306
 307         err = plain_format();
 308         if (err) {
 309                 pr_warn("hashing plain 'p' has unexpected format\n");
 310                 failed_tests++;
 311         }
 312 }
 313
 314 static void __init
 315 test_hashed(const char *fmt, const void *p)
 316 {
 317         char buf[PLAIN_BUF_SIZE];
 318         int ret;
 319
 320         /*
 321          * No need to increase failed test counter since this is assumed
 322          * to be called after plain().
 323          */
 324         ret = plain_hash_to_buffer(p, buf, PLAIN_BUF_SIZE);
 325         if (ret)
 326                 return;
 327
 328         test(buf, fmt, p);
 329 }
 330
 331 static void __init
 332 null_pointer(void)
 333 {
 334         test_hashed("%p", NULL);
 335         test(ZEROS "00000000", "%px", NULL);
 336         test("(null)", "%pE", NULL);
 337 }
 338
 339 #define PTR_INVALID ((void *)0x000000ab)
 340
 341 static void __init
 342 invalid_pointer(void)
 343 {
 344         test_hashed("%p", PTR_INVALID);
 345         test(ZEROS "000000ab", "%px", PTR_INVALID);
 346         test("(efault)", "%pE", PTR_INVALID);
 347 }
 348
 349 static void __init
 350 symbol_ptr(void)
 351 {
 352 }
 353
 354 static void __init
 355 kernel_ptr(void)
 356 {
 357         /* We can't test this without access to kptr_restrict. */
 358 }
 359
 360 static void __init
 361 struct_resource(void)
 362 {
 363 }
 364
 365 static void __init
 366 addr(void)
 367 {
 368 }
 369
 370 static void __init
 371 escaped_str(void)
 372 {
 373 }
 374
 375 static void __init
 376 hex_string(void)
 377 {
 378         const char buf[3] = {0xc0, 0xff, 0xee};
 379
 380         test("c0 ff ee|c0:ff:ee|c0-ff-ee|c0ffee",
 381              "%3ph|%3phC|%3phD|%3phN", buf, buf, buf, buf);
 382         test("c0 ff ee|c0:ff:ee|c0-ff-ee|c0ffee",
 383              "%*ph|%*phC|%*phD|%*phN", 3, buf, 3, buf, 3, buf, 3, buf);
 384 }
 385
 386 static void __init
 387 mac(void)
 388 {
 389         const u8 addr[6] = {0x2d, 0x48, 0xd6, 0xfc, 0x7a, 0x05};
 390
 391         test("2d:48:d6:fc:7a:05", "%pM", addr);
 392         test("05:7a:fc:d6:48:2d", "%pMR", addr);
 393         test("2d-48-d6-fc-7a-05", "%pMF", addr);
 394         test("2d48d6fc7a05", "%pm", addr);
 395         test("057afcd6482d", "%pmR", addr);
 396 }
 397
 398 static void __init
 399 ip4(void)
 400 {
 401         struct sockaddr_in sa;
 402
 403         sa.sin_family = AF_INET;
 404         sa.sin_port = cpu_to_be16(12345);
 405         sa.sin_addr.s_addr = cpu_to_be32(0x7f000001);
 406
 407         test("127.000.000.001|127.0.0.1", "%pi4|%pI4", &sa.sin_addr, &sa.sin_addr);
 408         test("127.000.000.001|127.0.0.1", "%piS|%pIS", &sa, &sa);
 409         sa.sin_addr.s_addr = cpu_to_be32(0x01020304);
 410         test("001.002.003.004:12345|1.2.3.4:12345", "%piSp|%pISp", &sa, &sa);
 411 }
 412
 413 static void __init
 414 ip6(void)
 415 {
 416 }
 417
 418 static void __init
 419 ip(void)
 420 {
 421         ip4();
 422         ip6();
 423 }
 424
 425 static void __init
 426 uuid(void)
 427 {
 428         const char uuid[16] = {0x0, 0x1, 0x2, 0x3, 0x4, 0x5, 0x6, 0x7,
 429                                0x8, 0x9, 0xa, 0xb, 0xc, 0xd, 0xe, 0xf};
 430
 431         test("00010203-0405-0607-0809-0a0b0c0d0e0f", "%pUb", uuid);
 432         test("00010203-0405-0607-0809-0A0B0C0D0E0F", "%pUB", uuid);
 433         test("03020100-0504-0706-0809-0a0b0c0d0e0f", "%pUl", uuid);
 434         test("03020100-0504-0706-0809-0A0B0C0D0E0F", "%pUL", uuid);
 435 }
 436
 437 static struct dentry test_dentry[4] __initdata = {
 438         { .d_parent = &test_dentry[0],
 439           .d_name = QSTR_INIT(test_dentry[0].d_iname, 3),
 440           .d_iname = "foo" },
 441         { .d_parent = &test_dentry[0],
 442           .d_name = QSTR_INIT(test_dentry[1].d_iname, 5),
 443           .d_iname = "bravo" },
 444         { .d_parent = &test_dentry[1],
 445           .d_name = QSTR_INIT(test_dentry[2].d_iname, 4),
 446           .d_iname = "alfa" },
 447         { .d_parent = &test_dentry[2],
 448           .d_name = QSTR_INIT(test_dentry[3].d_iname, 5),
 449           .d_iname = "romeo" },
 450 };
 451
 452 static void __init
 453 dentry(void)
 454 {
 455         test("foo", "%pd", &test_dentry[0]);
 456         test("foo", "%pd2", &test_dentry[0]);
 457
 458         test("romeo", "%pd", &test_dentry[3]);
 459         test("alfa/romeo", "%pd2", &test_dentry[3]);
 460         test("bravo/alfa/romeo", "%pd3", &test_dentry[3]);
 461         test("/bravo/alfa/romeo", "%pd4", &test_dentry[3]);
 462         test("/bravo/alfa", "%pd4", &test_dentry[2]);
 463
 464         test("bravo/alfa  |bravo/alfa  ", "%-12pd2|%*pd2", &test_dentry[2], -12, &test_dentry[2]);
 465         test("  bravo/alfa|  bravo/alfa", "%12pd2|%*pd2", &test_dentry[2], 12, &test_dentry[2]);
 466 }
 467
 468 static void __init
 469 struct_va_format(void)
 470 {
 471 }
 472
 473 static void __init
 474 struct_rtc_time(void)
 475 {
 476         /* 1543210543 */
 477         const struct rtc_time tm = {
 478                 .tm_sec = 43,
 479                 .tm_min = 35,
 480                 .tm_hour = 5,
 481                 .tm_mday = 26,
 482                 .tm_mon = 10,
 483                 .tm_year = 118,
 484         };
 485
 486         test("(%ptR?)", "%pt", &tm);
 487         test("2018-11-26T05:35:43", "%ptR", &tm);
 488         test("0118-10-26T05:35:43", "%ptRr", &tm);
 489         test("05:35:43|2018-11-26", "%ptRt|%ptRd", &tm, &tm);
 490         test("05:35:43|0118-10-26", "%ptRtr|%ptRdr", &tm, &tm);
 491         test("05:35:43|2018-11-26", "%ptRttr|%ptRdtr", &tm, &tm);
 492         test("05:35:43 tr|2018-11-26 tr", "%ptRt tr|%ptRd tr", &tm, &tm);
 493 }
 494
 495 static void __init
 496 struct_clk(void)
 497 {
 498 }
 499
 500 static void __init
 501 large_bitmap(void)
 502 {
 503         const int nbits = 1 << 16;
 504         unsigned long *bits = bitmap_zalloc(nbits, GFP_KERNEL);
 505         if (!bits)
 506                 return;
 507
 508         bitmap_set(bits, 1, 20);
 509         bitmap_set(bits, 60000, 15);
 510         test("1-20,60000-60014", "%*pbl", nbits, bits);
 511         bitmap_free(bits);
 512 }
 513
 514 static void __init
 515 bitmap(void)
 516 {
 517         DECLARE_BITMAP(bits, 20);
 518         const int primes[] = {2,3,5,7,11,13,17,19};
 519         int i;
 520
 521         bitmap_zero(bits, 20);
 522         test("00000|00000", "%20pb|%*pb", bits, 20, bits);
 523         test("|", "%20pbl|%*pbl", bits, 20, bits);
 524
 525         for (i = 0; i < ARRAY_SIZE(primes); ++i)
 526                 set_bit(primes[i], bits);
 527         test("a28ac|a28ac", "%20pb|%*pb", bits, 20, bits);
 528         test("2-3,5,7,11,13,17,19|2-3,5,7,11,13,17,19", "%20pbl|%*pbl", bits, 20, bits);
 529
 530         bitmap_fill(bits, 20);
 531         test("fffff|fffff", "%20pb|%*pb", bits, 20, bits);
 532         test("0-19|0-19", "%20pbl|%*pbl", bits, 20, bits);
 533
 534         large_bitmap();
 535 }
 536
 537 static void __init
 538 netdev_features(void)
 539 {
 540 }
 541
 542 static void __init
 543 flags(void)
 544 {
 545         unsigned long flags;
 546         gfp_t gfp;
 547         char *cmp_buffer;
 548
 549         flags = 0;
 550         test("", "%pGp", &flags);
 551
 552         /* Page flags should filter the zone id */
 553         flags = 1UL << NR_PAGEFLAGS;
 554         test("", "%pGp", &flags);
 555
 556         flags |= 1UL << PG_uptodate | 1UL << PG_dirty | 1UL << PG_lru
 557                 | 1UL << PG_active | 1UL << PG_swapbacked;
 558         test("uptodate|dirty|lru|active|swapbacked", "%pGp", &flags);
 559
 560
 561         flags = VM_READ | VM_EXEC | VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC
 562                         | VM_DENYWRITE;
 563         test("read|exec|mayread|maywrite|mayexec|denywrite", "%pGv", &flags);
 564
 565         gfp = GFP_TRANSHUGE;
 566         test("GFP_TRANSHUGE", "%pGg", &gfp);
 567
 568         gfp = GFP_ATOMIC|__GFP_DMA;
 569         test("GFP_ATOMIC|GFP_DMA", "%pGg", &gfp);
 570
 571         gfp = __GFP_ATOMIC;
 572         test("__GFP_ATOMIC", "%pGg", &gfp);
 573
 574         cmp_buffer = kmalloc(BUF_SIZE, GFP_KERNEL);
 575         if (!cmp_buffer)
 576                 return;
 577
 578         /* Any flags not translated by the table should remain numeric */
 579         gfp = ~__GFP_BITS_MASK;
 580         snprintf(cmp_buffer, BUF_SIZE, "%#lx", (unsigned long) gfp);
 581         test(cmp_buffer, "%pGg", &gfp);
 582
 583         snprintf(cmp_buffer, BUF_SIZE, "__GFP_ATOMIC|%#lx",
 584                                                         (unsigned long) gfp);
 585         gfp |= __GFP_ATOMIC;
 586         test(cmp_buffer, "%pGg", &gfp);
 587
 588         kfree(cmp_buffer);
 589 }
 590
 591 static void __init
 592 test_pointer(void)
 593 {
 594         plain();
 595         null_pointer();
 596         invalid_pointer();
 597         symbol_ptr();
 598         kernel_ptr();
 599         struct_resource();
 600         addr();
 601         escaped_str();
 602         hex_string();
 603         mac();
 604         ip();
 605         uuid();
 606         dentry();
 607         struct_va_format();
 608         struct_rtc_time();
 609         struct_clk();
 610         bitmap();
 611         netdev_features();
 612         flags();
 613 }
 614
 615 static void __init selftest(void)
 616 {
 617         alloced_buffer = kmalloc(BUF_SIZE + 2*PAD_SIZE, GFP_KERNEL);
 618         if (!alloced_buffer)
 619                 return;
 620         test_buffer = alloced_buffer + PAD_SIZE;
 621
 622         test_basic();
 623         test_number();
 624         test_string();
 625         test_pointer();
 626
 627         kfree(alloced_buffer);
 628 }
 629
 630 KSTM_MODULE_LOADERS(test_printf);
 631 MODULE_AUTHOR("Rasmus Villemoes <linux@rasmusvillemoes.dk>");
 632 MODULE_LICENSE("GPL");