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