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