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 #define BUF_SIZE 256
  21 #define PAD_SIZE 16
  22 #define FILL_CHAR '$'
  23
  24 #define PTR1 ((void*)0x01234567)
  25 #define PTR2 ((void*)(long)(int)0xfedcba98)
  26
  27 #if BITS_PER_LONG == 64
  28 #define PTR1_ZEROES "000000000"
  29 #define PTR1_SPACES "         "
  30 #define PTR1_STR "1234567"
  31 #define PTR2_STR "fffffffffedcba98"
  32 #define PTR_WIDTH 16
  33 #else
  34 #define PTR1_ZEROES "0"
  35 #define PTR1_SPACES " "
  36 #define PTR1_STR "1234567"
  37 #define PTR2_STR "fedcba98"
  38 #define PTR_WIDTH 8
  39 #endif
  40 #define PTR_WIDTH_STR stringify(PTR_WIDTH)
  41
  42 static unsigned total_tests __initdata;
  43 static unsigned failed_tests __initdata;
  44 static char *test_buffer __initdata;
  45 static char *alloced_buffer __initdata;
  46
  47 static int __printf(4, 0) __init
  48 do_test(int bufsize, const char *expect, int elen,
  49         const char *fmt, va_list ap)
  50 {
  51         va_list aq;
  52         int ret, written;
  53
  54         total_tests++;
  55
  56         memset(alloced_buffer, FILL_CHAR, BUF_SIZE + 2*PAD_SIZE);
  57         va_copy(aq, ap);
  58         ret = vsnprintf(test_buffer, bufsize, fmt, aq);
  59         va_end(aq);
  60
  61         if (ret != elen) {
  62                 pr_warn("vsnprintf(buf, %d, \"%s\", ...) returned %d, expected %d\n",
  63                         bufsize, fmt, ret, elen);
  64                 return 1;
  65         }
  66
  67         if (memchr_inv(alloced_buffer, FILL_CHAR, PAD_SIZE)) {
  68                 pr_warn("vsnprintf(buf, %d, \"%s\", ...) wrote before buffer\n", bufsize, fmt);
  69                 return 1;
  70         }
  71
  72         if (!bufsize) {
  73                 if (memchr_inv(test_buffer, FILL_CHAR, BUF_SIZE + PAD_SIZE)) {
  74                         pr_warn("vsnprintf(buf, 0, \"%s\", ...) wrote to buffer\n",
  75                                 fmt);
  76                         return 1;
  77                 }
  78                 return 0;
  79         }
  80
  81         written = min(bufsize-1, elen);
  82         if (test_buffer[written]) {
  83                 pr_warn("vsnprintf(buf, %d, \"%s\", ...) did not nul-terminate buffer\n",
  84                         bufsize, fmt);
  85                 return 1;
  86         }
  87
  88         if (memchr_inv(test_buffer + written + 1, FILL_CHAR, BUF_SIZE + PAD_SIZE - (written + 1))) {
  89                 pr_warn("vsnprintf(buf, %d, \"%s\", ...) wrote beyond the nul-terminator\n",
  90                         bufsize, fmt);
  91                 return 1;
  92         }
  93
  94         if (memcmp(test_buffer, expect, written)) {
  95                 pr_warn("vsnprintf(buf, %d, \"%s\", ...) wrote '%s', expected '%.*s'\n",
  96                         bufsize, fmt, test_buffer, written, expect);
  97                 return 1;
  98         }
  99         return 0;
 100 }
 101
 102 static void __printf(3, 4) __init
 103 __test(const char *expect, int elen, const char *fmt, ...)
 104 {
 105         va_list ap;
 106         int rand;
 107         char *p;
 108
 109         if (elen >= BUF_SIZE) {
 110                 pr_err("error in test suite: expected output length %d too long. Format was '%s'.\n",
 111                        elen, fmt);
 112                 failed_tests++;
 113                 return;
 114         }
 115
 116         va_start(ap, fmt);
 117
 118         /*
 119          * Every fmt+args is subjected to four tests: Three where we
 120          * tell vsnprintf varying buffer sizes (plenty, not quite
 121          * enough and 0), and then we also test that kvasprintf would
 122          * be able to print it as expected.
 123          */
 124         failed_tests += do_test(BUF_SIZE, expect, elen, fmt, ap);
 125         rand = 1 + prandom_u32_max(elen+1);
 126         /* Since elen < BUF_SIZE, we have 1 <= rand <= BUF_SIZE. */
 127         failed_tests += do_test(rand, expect, elen, fmt, ap);
 128         failed_tests += do_test(0, expect, elen, fmt, ap);
 129
 130         p = kvasprintf(GFP_KERNEL, fmt, ap);
 131         if (p) {
 132                 total_tests++;
 133                 if (memcmp(p, expect, elen+1)) {
 134                         pr_warn("kvasprintf(..., \"%s\", ...) returned '%s', expected '%s'\n",
 135                                 fmt, p, expect);
 136                         failed_tests++;
 137                 }
 138                 kfree(p);
 139         }
 140         va_end(ap);
 141 }
 142
 143 #define test(expect, fmt, ...)                                  \
 144         __test(expect, strlen(expect), fmt, ##__VA_ARGS__)
 145
 146 static void __init
 147 test_basic(void)
 148 {
 149         /* Work around annoying "warning: zero-length gnu_printf format string". */
 150         char nul = '\0';
 151
 152         test("", &nul);
 153         test("100%", "100%%");
 154         test("xxx%yyy", "xxx%cyyy", '%');
 155         __test("xxx\0yyy", 7, "xxx%cyyy", '\0');
 156 }
 157
 158 static void __init
 159 test_number(void)
 160 {
 161         test("0x1234abcd  ", "%#-12x", 0x1234abcd);
 162         test("  0x1234abcd", "%#12x", 0x1234abcd);
 163         test("0|001| 12|+123| 1234|-123|-1234", "%d|%03d|%3d|%+d|% d|%+d|% d", 0, 1, 12, 123, 1234, -123, -1234);
 164         test("0|1|1|128|255", "%hhu|%hhu|%hhu|%hhu|%hhu", 0, 1, 257, 128, -1);
 165         test("0|1|1|-128|-1", "%hhd|%hhd|%hhd|%hhd|%hhd", 0, 1, 257, 128, -1);
 166         test("2015122420151225", "%ho%ho%#ho", 1037, 5282, -11627);
 167         /*
 168          * POSIX/C99: »The result of converting zero with an explicit
 169          * precision of zero shall be no characters.« Hence the output
 170          * from the below test should really be "00|0||| ". However,
 171          * the kernel's printf also produces a single 0 in that
 172          * case. This test case simply documents the current
 173          * behaviour.
 174          */
 175         test("00|0|0|0|0", "%.2d|%.1d|%.0d|%.*d|%1.0d", 0, 0, 0, 0, 0, 0);
 176 #ifndef __CHAR_UNSIGNED__
 177         {
 178                 /*
 179                  * Passing a 'char' to a %02x specifier doesn't do
 180                  * what was presumably the intention when char is
 181                  * signed and the value is negative. One must either &
 182                  * with 0xff or cast to u8.
 183                  */
 184                 char val = -16;
 185                 test("0xfffffff0|0xf0|0xf0", "%#02x|%#02x|%#02x", val, val & 0xff, (u8)val);
 186         }
 187 #endif
 188 }
 189
 190 static void __init
 191 test_string(void)
 192 {
 193         test("", "%s%.0s", "", "123");
 194         test("ABCD|abc|123", "%s|%.3s|%.*s", "ABCD", "abcdef", 3, "123456");
 195         test("1  |  2|3  |  4|5  ", "%-3s|%3s|%-*s|%*s|%*s", "1", "2", 3, "3", 3, "4", -3, "5");
 196         test("1234      ", "%-10.4s", "123456");
 197         test("      1234", "%10.4s", "123456");
 198         /*
 199          * POSIX and C99 say that a negative precision (which is only
 200          * possible to pass via a * argument) should be treated as if
 201          * the precision wasn't present, and that if the precision is
 202          * omitted (as in %.s), the precision should be taken to be
 203          * 0. However, the kernel's printf behave exactly opposite,
 204          * treating a negative precision as 0 and treating an omitted
 205          * precision specifier as if no precision was given.
 206          *
 207          * These test cases document the current behaviour; should
 208          * anyone ever feel the need to follow the standards more
 209          * closely, this can be revisited.
 210          */
 211         test("    ", "%4.*s", -5, "123456");
 212         test("123456", "%.s", "123456");
 213         test("a||", "%.s|%.0s|%.*s", "a", "b", 0, "c");
 214         test("a  |   |   ", "%-3.s|%-3.0s|%-3.*s", "a", "b", 0, "c");
 215 }
 216
 217 static void __init
 218 plain(void)
 219 {
 220         test(PTR1_ZEROES PTR1_STR " " PTR2_STR, "%p %p", PTR1, PTR2);
 221         /*
 222          * The field width is overloaded for some %p extensions to
 223          * pass another piece of information. For plain pointers, the
 224          * behaviour is slightly odd: One cannot pass either the 0
 225          * flag nor a precision to %p without gcc complaining, and if
 226          * one explicitly gives a field width, the number is no longer
 227          * zero-padded.
 228          */
 229         test("|" PTR1_STR PTR1_SPACES "  |  " PTR1_SPACES PTR1_STR "|",
 230              "|%-*p|%*p|", PTR_WIDTH+2, PTR1, PTR_WIDTH+2, PTR1);
 231         test("|" PTR2_STR "  |  " PTR2_STR "|",
 232              "|%-*p|%*p|", PTR_WIDTH+2, PTR2, PTR_WIDTH+2, PTR2);
 233
 234         /*
 235          * Unrecognized %p extensions are treated as plain %p, but the
 236          * alphanumeric suffix is ignored (that is, does not occur in
 237          * the output.)
 238          */
 239         test("|"PTR1_ZEROES PTR1_STR"|", "|%p0y|", PTR1);
 240         test("|"PTR2_STR"|", "|%p0y|", PTR2);
 241 }
 242
 243 static void __init
 244 symbol_ptr(void)
 245 {
 246 }
 247
 248 static void __init
 249 kernel_ptr(void)
 250 {
 251 }
 252
 253 static void __init
 254 struct_resource(void)
 255 {
 256 }
 257
 258 static void __init
 259 addr(void)
 260 {
 261 }
 262
 263 static void __init
 264 escaped_str(void)
 265 {
 266 }
 267
 268 static void __init
 269 hex_string(void)
 270 {
 271         const char buf[3] = {0xc0, 0xff, 0xee};
 272
 273         test("c0 ff ee|c0:ff:ee|c0-ff-ee|c0ffee",
 274              "%3ph|%3phC|%3phD|%3phN", buf, buf, buf, buf);
 275         test("c0 ff ee|c0:ff:ee|c0-ff-ee|c0ffee",
 276              "%*ph|%*phC|%*phD|%*phN", 3, buf, 3, buf, 3, buf, 3, buf);
 277 }
 278
 279 static void __init
 280 mac(void)
 281 {
 282         const u8 addr[6] = {0x2d, 0x48, 0xd6, 0xfc, 0x7a, 0x05};
 283
 284         test("2d:48:d6:fc:7a:05", "%pM", addr);
 285         test("05:7a:fc:d6:48:2d", "%pMR", addr);
 286         test("2d-48-d6-fc-7a-05", "%pMF", addr);
 287         test("2d48d6fc7a05", "%pm", addr);
 288         test("057afcd6482d", "%pmR", addr);
 289 }
 290
 291 static void __init
 292 ip4(void)
 293 {
 294         struct sockaddr_in sa;
 295
 296         sa.sin_family = AF_INET;
 297         sa.sin_port = cpu_to_be16(12345);
 298         sa.sin_addr.s_addr = cpu_to_be32(0x7f000001);
 299
 300         test("127.000.000.001|127.0.0.1", "%pi4|%pI4", &sa.sin_addr, &sa.sin_addr);
 301         test("127.000.000.001|127.0.0.1", "%piS|%pIS", &sa, &sa);
 302         sa.sin_addr.s_addr = cpu_to_be32(0x01020304);
 303         test("001.002.003.004:12345|1.2.3.4:12345", "%piSp|%pISp", &sa, &sa);
 304 }
 305
 306 static void __init
 307 ip6(void)
 308 {
 309 }
 310
 311 static void __init
 312 ip(void)
 313 {
 314         ip4();
 315         ip6();
 316 }
 317
 318 static void __init
 319 uuid(void)
 320 {
 321         const char uuid[16] = {0x0, 0x1, 0x2, 0x3, 0x4, 0x5, 0x6, 0x7,
 322                                0x8, 0x9, 0xa, 0xb, 0xc, 0xd, 0xe, 0xf};
 323
 324         test("00010203-0405-0607-0809-0a0b0c0d0e0f", "%pUb", uuid);
 325         test("00010203-0405-0607-0809-0A0B0C0D0E0F", "%pUB", uuid);
 326         test("03020100-0504-0706-0809-0a0b0c0d0e0f", "%pUl", uuid);
 327         test("03020100-0504-0706-0809-0A0B0C0D0E0F", "%pUL", uuid);
 328 }
 329
 330 static struct dentry test_dentry[4] __initdata = {
 331         { .d_parent = &test_dentry[0],
 332           .d_name = QSTR_INIT(test_dentry[0].d_iname, 3),
 333           .d_iname = "foo" },
 334         { .d_parent = &test_dentry[0],
 335           .d_name = QSTR_INIT(test_dentry[1].d_iname, 5),
 336           .d_iname = "bravo" },
 337         { .d_parent = &test_dentry[1],
 338           .d_name = QSTR_INIT(test_dentry[2].d_iname, 4),
 339           .d_iname = "alfa" },
 340         { .d_parent = &test_dentry[2],
 341           .d_name = QSTR_INIT(test_dentry[3].d_iname, 5),
 342           .d_iname = "romeo" },
 343 };
 344
 345 static void __init
 346 dentry(void)
 347 {
 348         test("foo", "%pd", &test_dentry[0]);
 349         test("foo", "%pd2", &test_dentry[0]);
 350
 351         test("romeo", "%pd", &test_dentry[3]);
 352         test("alfa/romeo", "%pd2", &test_dentry[3]);
 353         test("bravo/alfa/romeo", "%pd3", &test_dentry[3]);
 354         test("/bravo/alfa/romeo", "%pd4", &test_dentry[3]);
 355         test("/bravo/alfa", "%pd4", &test_dentry[2]);
 356
 357         test("bravo/alfa  |bravo/alfa  ", "%-12pd2|%*pd2", &test_dentry[2], -12, &test_dentry[2]);
 358         test("  bravo/alfa|  bravo/alfa", "%12pd2|%*pd2", &test_dentry[2], 12, &test_dentry[2]);
 359 }
 360
 361 static void __init
 362 struct_va_format(void)
 363 {
 364 }
 365
 366 static void __init
 367 struct_clk(void)
 368 {
 369 }
 370
 371 static void __init
 372 large_bitmap(void)
 373 {
 374         const int nbits = 1 << 16;
 375         unsigned long *bits = kcalloc(BITS_TO_LONGS(nbits), sizeof(long), GFP_KERNEL);
 376         if (!bits)
 377                 return;
 378
 379         bitmap_set(bits, 1, 20);
 380         bitmap_set(bits, 60000, 15);
 381         test("1-20,60000-60014", "%*pbl", nbits, bits);
 382         kfree(bits);
 383 }
 384
 385 static void __init
 386 bitmap(void)
 387 {
 388         DECLARE_BITMAP(bits, 20);
 389         const int primes[] = {2,3,5,7,11,13,17,19};
 390         int i;
 391
 392         bitmap_zero(bits, 20);
 393         test("00000|00000", "%20pb|%*pb", bits, 20, bits);
 394         test("|", "%20pbl|%*pbl", bits, 20, bits);
 395
 396         for (i = 0; i < ARRAY_SIZE(primes); ++i)
 397                 set_bit(primes[i], bits);
 398         test("a28ac|a28ac", "%20pb|%*pb", bits, 20, bits);
 399         test("2-3,5,7,11,13,17,19|2-3,5,7,11,13,17,19", "%20pbl|%*pbl", bits, 20, bits);
 400
 401         bitmap_fill(bits, 20);
 402         test("fffff|fffff", "%20pb|%*pb", bits, 20, bits);
 403         test("0-19|0-19", "%20pbl|%*pbl", bits, 20, bits);
 404
 405         large_bitmap();
 406 }
 407
 408 static void __init
 409 netdev_features(void)
 410 {
 411 }
 412
 413 static void __init
 414 test_pointer(void)
 415 {
 416         plain();
 417         symbol_ptr();
 418         kernel_ptr();
 419         struct_resource();
 420         addr();
 421         escaped_str();
 422         hex_string();
 423         mac();
 424         ip();
 425         uuid();
 426         dentry();
 427         struct_va_format();
 428         struct_clk();
 429         bitmap();
 430         netdev_features();
 431 }
 432
 433 static int __init
 434 test_printf_init(void)
 435 {
 436         alloced_buffer = kmalloc(BUF_SIZE + 2*PAD_SIZE, GFP_KERNEL);
 437         if (!alloced_buffer)
 438                 return -ENOMEM;
 439         test_buffer = alloced_buffer + PAD_SIZE;
 440
 441         test_basic();
 442         test_number();
 443         test_string();
 444         test_pointer();
 445
 446         kfree(alloced_buffer);
 447
 448         if (failed_tests == 0)
 449                 pr_info("all %u tests passed\n", total_tests);
 450         else
 451                 pr_warn("failed %u out of %u tests\n", failed_tests, total_tests);
 452
 453         return failed_tests ? -EINVAL : 0;
 454 }
 455
 456 module_init(test_printf_init);
 457
 458 MODULE_AUTHOR("Rasmus Villemoes <linux@rasmusvillemoes.dk>");
 459 MODULE_LICENSE("GPL");