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 #define PTR1 ((void*)0x01234567)
  28 #define PTR2 ((void*)(long)(int)0xfedcba98)
  29
  30 #if BITS_PER_LONG == 64
  31 #define PTR1_ZEROES "000000000"
  32 #define PTR1_SPACES "         "
  33 #define PTR1_STR "1234567"
  34 #define PTR2_STR "fffffffffedcba98"
  35 #define PTR_WIDTH 16
  36 #else
  37 #define PTR1_ZEROES "0"
  38 #define PTR1_SPACES " "
  39 #define PTR1_STR "1234567"
  40 #define PTR2_STR "fedcba98"
  41 #define PTR_WIDTH 8
  42 #endif
  43 #define PTR_WIDTH_STR stringify(PTR_WIDTH)
  44
  45 static unsigned total_tests __initdata;
  46 static unsigned failed_tests __initdata;
  47 static char *test_buffer __initdata;
  48 static char *alloced_buffer __initdata;
  49
  50 static int __printf(4, 0) __init
  51 do_test(int bufsize, const char *expect, int elen,
  52         const char *fmt, va_list ap)
  53 {
  54         va_list aq;
  55         int ret, written;
  56
  57         total_tests++;
  58
  59         memset(alloced_buffer, FILL_CHAR, BUF_SIZE + 2*PAD_SIZE);
  60         va_copy(aq, ap);
  61         ret = vsnprintf(test_buffer, bufsize, fmt, aq);
  62         va_end(aq);
  63
  64         if (ret != elen) {
  65                 pr_warn("vsnprintf(buf, %d, \"%s\", ...) returned %d, expected %d\n",
  66                         bufsize, fmt, ret, elen);
  67                 return 1;
  68         }
  69
  70         if (memchr_inv(alloced_buffer, FILL_CHAR, PAD_SIZE)) {
  71                 pr_warn("vsnprintf(buf, %d, \"%s\", ...) wrote before buffer\n", bufsize, fmt);
  72                 return 1;
  73         }
  74
  75         if (!bufsize) {
  76                 if (memchr_inv(test_buffer, FILL_CHAR, BUF_SIZE + PAD_SIZE)) {
  77                         pr_warn("vsnprintf(buf, 0, \"%s\", ...) wrote to buffer\n",
  78                                 fmt);
  79                         return 1;
  80                 }
  81                 return 0;
  82         }
  83
  84         written = min(bufsize-1, elen);
  85         if (test_buffer[written]) {
  86                 pr_warn("vsnprintf(buf, %d, \"%s\", ...) did not nul-terminate buffer\n",
  87                         bufsize, fmt);
  88                 return 1;
  89         }
  90
  91         if (memchr_inv(test_buffer + written + 1, FILL_CHAR, BUF_SIZE + PAD_SIZE - (written + 1))) {
  92                 pr_warn("vsnprintf(buf, %d, \"%s\", ...) wrote beyond the nul-terminator\n",
  93                         bufsize, fmt);
  94                 return 1;
  95         }
  96
  97         if (memcmp(test_buffer, expect, written)) {
  98                 pr_warn("vsnprintf(buf, %d, \"%s\", ...) wrote '%s', expected '%.*s'\n",
  99                         bufsize, fmt, test_buffer, written, expect);
 100                 return 1;
 101         }
 102         return 0;
 103 }
 104
 105 static void __printf(3, 4) __init
 106 __test(const char *expect, int elen, const char *fmt, ...)
 107 {
 108         va_list ap;
 109         int rand;
 110         char *p;
 111
 112         if (elen >= BUF_SIZE) {
 113                 pr_err("error in test suite: expected output length %d too long. Format was '%s'.\n",
 114                        elen, fmt);
 115                 failed_tests++;
 116                 return;
 117         }
 118
 119         va_start(ap, fmt);
 120
 121         /*
 122          * Every fmt+args is subjected to four tests: Three where we
 123          * tell vsnprintf varying buffer sizes (plenty, not quite
 124          * enough and 0), and then we also test that kvasprintf would
 125          * be able to print it as expected.
 126          */
 127         failed_tests += do_test(BUF_SIZE, expect, elen, fmt, ap);
 128         rand = 1 + prandom_u32_max(elen+1);
 129         /* Since elen < BUF_SIZE, we have 1 <= rand <= BUF_SIZE. */
 130         failed_tests += do_test(rand, expect, elen, fmt, ap);
 131         failed_tests += do_test(0, expect, elen, fmt, ap);
 132
 133         p = kvasprintf(GFP_KERNEL, fmt, ap);
 134         if (p) {
 135                 total_tests++;
 136                 if (memcmp(p, expect, elen+1)) {
 137                         pr_warn("kvasprintf(..., \"%s\", ...) returned '%s', expected '%s'\n",
 138                                 fmt, p, expect);
 139                         failed_tests++;
 140                 }
 141                 kfree(p);
 142         }
 143         va_end(ap);
 144 }
 145
 146 #define test(expect, fmt, ...)                                  \
 147         __test(expect, strlen(expect), fmt, ##__VA_ARGS__)
 148
 149 static void __init
 150 test_basic(void)
 151 {
 152         /* Work around annoying "warning: zero-length gnu_printf format string". */
 153         char nul = '\0';
 154
 155         test("", &nul);
 156         test("100%", "100%%");
 157         test("xxx%yyy", "xxx%cyyy", '%');
 158         __test("xxx\0yyy", 7, "xxx%cyyy", '\0');
 159 }
 160
 161 static void __init
 162 test_number(void)
 163 {
 164         test("0x1234abcd  ", "%#-12x", 0x1234abcd);
 165         test("  0x1234abcd", "%#12x", 0x1234abcd);
 166         test("0|001| 12|+123| 1234|-123|-1234", "%d|%03d|%3d|%+d|% d|%+d|% d", 0, 1, 12, 123, 1234, -123, -1234);
 167         test("0|1|1|128|255", "%hhu|%hhu|%hhu|%hhu|%hhu", 0, 1, 257, 128, -1);
 168         test("0|1|1|-128|-1", "%hhd|%hhd|%hhd|%hhd|%hhd", 0, 1, 257, 128, -1);
 169         test("2015122420151225", "%ho%ho%#ho", 1037, 5282, -11627);
 170         /*
 171          * POSIX/C99: »The result of converting zero with an explicit
 172          * precision of zero shall be no characters.« Hence the output
 173          * from the below test should really be "00|0||| ". However,
 174          * the kernel's printf also produces a single 0 in that
 175          * case. This test case simply documents the current
 176          * behaviour.
 177          */
 178         test("00|0|0|0|0", "%.2d|%.1d|%.0d|%.*d|%1.0d", 0, 0, 0, 0, 0, 0);
 179 #ifndef __CHAR_UNSIGNED__
 180         {
 181                 /*
 182                  * Passing a 'char' to a %02x specifier doesn't do
 183                  * what was presumably the intention when char is
 184                  * signed and the value is negative. One must either &
 185                  * with 0xff or cast to u8.
 186                  */
 187                 char val = -16;
 188                 test("0xfffffff0|0xf0|0xf0", "%#02x|%#02x|%#02x", val, val & 0xff, (u8)val);
 189         }
 190 #endif
 191 }
 192
 193 static void __init
 194 test_string(void)
 195 {
 196         test("", "%s%.0s", "", "123");
 197         test("ABCD|abc|123", "%s|%.3s|%.*s", "ABCD", "abcdef", 3, "123456");
 198         test("1  |  2|3  |  4|5  ", "%-3s|%3s|%-*s|%*s|%*s", "1", "2", 3, "3", 3, "4", -3, "5");
 199         test("1234      ", "%-10.4s", "123456");
 200         test("      1234", "%10.4s", "123456");
 201         /*
 202          * POSIX and C99 say that a negative precision (which is only
 203          * possible to pass via a * argument) should be treated as if
 204          * the precision wasn't present, and that if the precision is
 205          * omitted (as in %.s), the precision should be taken to be
 206          * 0. However, the kernel's printf behave exactly opposite,
 207          * treating a negative precision as 0 and treating an omitted
 208          * precision specifier as if no precision was given.
 209          *
 210          * These test cases document the current behaviour; should
 211          * anyone ever feel the need to follow the standards more
 212          * closely, this can be revisited.
 213          */
 214         test("    ", "%4.*s", -5, "123456");
 215         test("123456", "%.s", "123456");
 216         test("a||", "%.s|%.0s|%.*s", "a", "b", 0, "c");
 217         test("a  |   |   ", "%-3.s|%-3.0s|%-3.*s", "a", "b", 0, "c");
 218 }
 219
 220 static void __init
 221 plain(void)
 222 {
 223         test(PTR1_ZEROES PTR1_STR " " PTR2_STR, "%p %p", PTR1, PTR2);
 224         /*
 225          * The field width is overloaded for some %p extensions to
 226          * pass another piece of information. For plain pointers, the
 227          * behaviour is slightly odd: One cannot pass either the 0
 228          * flag nor a precision to %p without gcc complaining, and if
 229          * one explicitly gives a field width, the number is no longer
 230          * zero-padded.
 231          */
 232         test("|" PTR1_STR PTR1_SPACES "  |  " PTR1_SPACES PTR1_STR "|",
 233              "|%-*p|%*p|", PTR_WIDTH+2, PTR1, PTR_WIDTH+2, PTR1);
 234         test("|" PTR2_STR "  |  " PTR2_STR "|",
 235              "|%-*p|%*p|", PTR_WIDTH+2, PTR2, PTR_WIDTH+2, PTR2);
 236
 237         /*
 238          * Unrecognized %p extensions are treated as plain %p, but the
 239          * alphanumeric suffix is ignored (that is, does not occur in
 240          * the output.)
 241          */
 242         test("|"PTR1_ZEROES PTR1_STR"|", "|%p0y|", PTR1);
 243         test("|"PTR2_STR"|", "|%p0y|", PTR2);
 244 }
 245
 246 static void __init
 247 symbol_ptr(void)
 248 {
 249 }
 250
 251 static void __init
 252 kernel_ptr(void)
 253 {
 254 }
 255
 256 static void __init
 257 struct_resource(void)
 258 {
 259 }
 260
 261 static void __init
 262 addr(void)
 263 {
 264 }
 265
 266 static void __init
 267 escaped_str(void)
 268 {
 269 }
 270
 271 static void __init
 272 hex_string(void)
 273 {
 274         const char buf[3] = {0xc0, 0xff, 0xee};
 275
 276         test("c0 ff ee|c0:ff:ee|c0-ff-ee|c0ffee",
 277              "%3ph|%3phC|%3phD|%3phN", buf, buf, buf, buf);
 278         test("c0 ff ee|c0:ff:ee|c0-ff-ee|c0ffee",
 279              "%*ph|%*phC|%*phD|%*phN", 3, buf, 3, buf, 3, buf, 3, buf);
 280 }
 281
 282 static void __init
 283 mac(void)
 284 {
 285         const u8 addr[6] = {0x2d, 0x48, 0xd6, 0xfc, 0x7a, 0x05};
 286
 287         test("2d:48:d6:fc:7a:05", "%pM", addr);
 288         test("05:7a:fc:d6:48:2d", "%pMR", addr);
 289         test("2d-48-d6-fc-7a-05", "%pMF", addr);
 290         test("2d48d6fc7a05", "%pm", addr);
 291         test("057afcd6482d", "%pmR", addr);
 292 }
 293
 294 static void __init
 295 ip4(void)
 296 {
 297         struct sockaddr_in sa;
 298
 299         sa.sin_family = AF_INET;
 300         sa.sin_port = cpu_to_be16(12345);
 301         sa.sin_addr.s_addr = cpu_to_be32(0x7f000001);
 302
 303         test("127.000.000.001|127.0.0.1", "%pi4|%pI4", &sa.sin_addr, &sa.sin_addr);
 304         test("127.000.000.001|127.0.0.1", "%piS|%pIS", &sa, &sa);
 305         sa.sin_addr.s_addr = cpu_to_be32(0x01020304);
 306         test("001.002.003.004:12345|1.2.3.4:12345", "%piSp|%pISp", &sa, &sa);
 307 }
 308
 309 static void __init
 310 ip6(void)
 311 {
 312 }
 313
 314 static void __init
 315 ip(void)
 316 {
 317         ip4();
 318         ip6();
 319 }
 320
 321 static void __init
 322 uuid(void)
 323 {
 324         const char uuid[16] = {0x0, 0x1, 0x2, 0x3, 0x4, 0x5, 0x6, 0x7,
 325                                0x8, 0x9, 0xa, 0xb, 0xc, 0xd, 0xe, 0xf};
 326
 327         test("00010203-0405-0607-0809-0a0b0c0d0e0f", "%pUb", uuid);
 328         test("00010203-0405-0607-0809-0A0B0C0D0E0F", "%pUB", uuid);
 329         test("03020100-0504-0706-0809-0a0b0c0d0e0f", "%pUl", uuid);
 330         test("03020100-0504-0706-0809-0A0B0C0D0E0F", "%pUL", uuid);
 331 }
 332
 333 static struct dentry test_dentry[4] __initdata = {
 334         { .d_parent = &test_dentry[0],
 335           .d_name = QSTR_INIT(test_dentry[0].d_iname, 3),
 336           .d_iname = "foo" },
 337         { .d_parent = &test_dentry[0],
 338           .d_name = QSTR_INIT(test_dentry[1].d_iname, 5),
 339           .d_iname = "bravo" },
 340         { .d_parent = &test_dentry[1],
 341           .d_name = QSTR_INIT(test_dentry[2].d_iname, 4),
 342           .d_iname = "alfa" },
 343         { .d_parent = &test_dentry[2],
 344           .d_name = QSTR_INIT(test_dentry[3].d_iname, 5),
 345           .d_iname = "romeo" },
 346 };
 347
 348 static void __init
 349 dentry(void)
 350 {
 351         test("foo", "%pd", &test_dentry[0]);
 352         test("foo", "%pd2", &test_dentry[0]);
 353
 354         test("romeo", "%pd", &test_dentry[3]);
 355         test("alfa/romeo", "%pd2", &test_dentry[3]);
 356         test("bravo/alfa/romeo", "%pd3", &test_dentry[3]);
 357         test("/bravo/alfa/romeo", "%pd4", &test_dentry[3]);
 358         test("/bravo/alfa", "%pd4", &test_dentry[2]);
 359
 360         test("bravo/alfa  |bravo/alfa  ", "%-12pd2|%*pd2", &test_dentry[2], -12, &test_dentry[2]);
 361         test("  bravo/alfa|  bravo/alfa", "%12pd2|%*pd2", &test_dentry[2], 12, &test_dentry[2]);
 362 }
 363
 364 static void __init
 365 struct_va_format(void)
 366 {
 367 }
 368
 369 static void __init
 370 struct_clk(void)
 371 {
 372 }
 373
 374 static void __init
 375 large_bitmap(void)
 376 {
 377         const int nbits = 1 << 16;
 378         unsigned long *bits = kcalloc(BITS_TO_LONGS(nbits), sizeof(long), GFP_KERNEL);
 379         if (!bits)
 380                 return;
 381
 382         bitmap_set(bits, 1, 20);
 383         bitmap_set(bits, 60000, 15);
 384         test("1-20,60000-60014", "%*pbl", nbits, bits);
 385         kfree(bits);
 386 }
 387
 388 static void __init
 389 bitmap(void)
 390 {
 391         DECLARE_BITMAP(bits, 20);
 392         const int primes[] = {2,3,5,7,11,13,17,19};
 393         int i;
 394
 395         bitmap_zero(bits, 20);
 396         test("00000|00000", "%20pb|%*pb", bits, 20, bits);
 397         test("|", "%20pbl|%*pbl", bits, 20, bits);
 398
 399         for (i = 0; i < ARRAY_SIZE(primes); ++i)
 400                 set_bit(primes[i], bits);
 401         test("a28ac|a28ac", "%20pb|%*pb", bits, 20, bits);
 402         test("2-3,5,7,11,13,17,19|2-3,5,7,11,13,17,19", "%20pbl|%*pbl", bits, 20, bits);
 403
 404         bitmap_fill(bits, 20);
 405         test("fffff|fffff", "%20pb|%*pb", bits, 20, bits);
 406         test("0-19|0-19", "%20pbl|%*pbl", bits, 20, bits);
 407
 408         large_bitmap();
 409 }
 410
 411 static void __init
 412 netdev_features(void)
 413 {
 414 }
 415
 416 static void __init
 417 flags(void)
 418 {
 419         unsigned long flags;
 420         gfp_t gfp;
 421         char *cmp_buffer;
 422
 423         flags = 0;
 424         test("", "%pGp", &flags);
 425
 426         /* Page flags should filter the zone id */
 427         flags = 1UL << NR_PAGEFLAGS;
 428         test("", "%pGp", &flags);
 429
 430         flags |= 1UL << PG_uptodate | 1UL << PG_dirty | 1UL << PG_lru
 431                 | 1UL << PG_active | 1UL << PG_swapbacked;
 432         test("uptodate|dirty|lru|active|swapbacked", "%pGp", &flags);
 433
 434
 435         flags = VM_READ | VM_EXEC | VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC
 436                         | VM_DENYWRITE;
 437         test("read|exec|mayread|maywrite|mayexec|denywrite", "%pGv", &flags);
 438
 439         gfp = GFP_TRANSHUGE;
 440         test("GFP_TRANSHUGE", "%pGg", &gfp);
 441
 442         gfp = GFP_ATOMIC|__GFP_DMA;
 443         test("GFP_ATOMIC|GFP_DMA", "%pGg", &gfp);
 444
 445         gfp = __GFP_ATOMIC;
 446         test("__GFP_ATOMIC", "%pGg", &gfp);
 447
 448         cmp_buffer = kmalloc(BUF_SIZE, GFP_KERNEL);
 449         if (!cmp_buffer)
 450                 return;
 451
 452         /* Any flags not translated by the table should remain numeric */
 453         gfp = ~__GFP_BITS_MASK;
 454         snprintf(cmp_buffer, BUF_SIZE, "%#lx", (unsigned long) gfp);
 455         test(cmp_buffer, "%pGg", &gfp);
 456
 457         snprintf(cmp_buffer, BUF_SIZE, "__GFP_ATOMIC|%#lx",
 458                                                         (unsigned long) gfp);
 459         gfp |= __GFP_ATOMIC;
 460         test(cmp_buffer, "%pGg", &gfp);
 461
 462         kfree(cmp_buffer);
 463 }
 464
 465 static void __init
 466 test_pointer(void)
 467 {
 468         plain();
 469         symbol_ptr();
 470         kernel_ptr();
 471         struct_resource();
 472         addr();
 473         escaped_str();
 474         hex_string();
 475         mac();
 476         ip();
 477         uuid();
 478         dentry();
 479         struct_va_format();
 480         struct_clk();
 481         bitmap();
 482         netdev_features();
 483         flags();
 484 }
 485
 486 static int __init
 487 test_printf_init(void)
 488 {
 489         alloced_buffer = kmalloc(BUF_SIZE + 2*PAD_SIZE, GFP_KERNEL);
 490         if (!alloced_buffer)
 491                 return -ENOMEM;
 492         test_buffer = alloced_buffer + PAD_SIZE;
 493
 494         test_basic();
 495         test_number();
 496         test_string();
 497         test_pointer();
 498
 499         kfree(alloced_buffer);
 500
 501         if (failed_tests == 0)
 502                 pr_info("all %u tests passed\n", total_tests);
 503         else
 504                 pr_warn("failed %u out of %u tests\n", failed_tests, total_tests);
 505
 506         return failed_tests ? -EINVAL : 0;
 507 }
 508
 509 module_init(test_printf_init);
 510
 511 MODULE_AUTHOR("Rasmus Villemoes <linux@rasmusvillemoes.dk>");
 512 MODULE_LICENSE("GPL");