2 * Test cases for printf facility.
5 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
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>
15 #include <linux/bitmap.h>
16 #include <linux/dcache.h>
17 #include <linux/socket.h>
20 #include <linux/gfp.h>
27 static unsigned total_tests __initdata;
28 static unsigned failed_tests __initdata;
29 static char *test_buffer __initdata;
30 static char *alloced_buffer __initdata;
32 static int __printf(4, 0) __init
33 do_test(int bufsize, const char *expect, int elen,
34 const char *fmt, va_list ap)
41 memset(alloced_buffer, FILL_CHAR, BUF_SIZE + 2*PAD_SIZE);
43 ret = vsnprintf(test_buffer, bufsize, fmt, aq);
47 pr_warn("vsnprintf(buf, %d, \"%s\", ...) returned %d, expected %d\n",
48 bufsize, fmt, ret, elen);
52 if (memchr_inv(alloced_buffer, FILL_CHAR, PAD_SIZE)) {
53 pr_warn("vsnprintf(buf, %d, \"%s\", ...) wrote before buffer\n", bufsize, fmt);
58 if (memchr_inv(test_buffer, FILL_CHAR, BUF_SIZE + PAD_SIZE)) {
59 pr_warn("vsnprintf(buf, 0, \"%s\", ...) wrote to buffer\n",
66 written = min(bufsize-1, elen);
67 if (test_buffer[written]) {
68 pr_warn("vsnprintf(buf, %d, \"%s\", ...) did not nul-terminate buffer\n",
73 if (memchr_inv(test_buffer + written + 1, FILL_CHAR, BUF_SIZE + PAD_SIZE - (written + 1))) {
74 pr_warn("vsnprintf(buf, %d, \"%s\", ...) wrote beyond the nul-terminator\n",
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);
87 static void __printf(3, 4) __init
88 __test(const char *expect, int elen, const char *fmt, ...)
94 if (elen >= BUF_SIZE) {
95 pr_err("error in test suite: expected output length %d too long. Format was '%s'.\n",
104 * Every fmt+args is subjected to four tests: Three where we
105 * tell vsnprintf varying buffer sizes (plenty, not quite
106 * enough and 0), and then we also test that kvasprintf would
107 * be able to print it as expected.
109 failed_tests += do_test(BUF_SIZE, expect, elen, fmt, ap);
110 rand = 1 + prandom_u32_max(elen+1);
111 /* Since elen < BUF_SIZE, we have 1 <= rand <= BUF_SIZE. */
112 failed_tests += do_test(rand, expect, elen, fmt, ap);
113 failed_tests += do_test(0, expect, elen, fmt, ap);
115 p = kvasprintf(GFP_KERNEL, fmt, ap);
118 if (memcmp(p, expect, elen+1)) {
119 pr_warn("kvasprintf(..., \"%s\", ...) returned '%s', expected '%s'\n",
128 #define test(expect, fmt, ...) \
129 __test(expect, strlen(expect), fmt, ##__VA_ARGS__)
134 /* Work around annoying "warning: zero-length gnu_printf format string". */
138 test("100%", "100%%");
139 test("xxx%yyy", "xxx%cyyy", '%');
140 __test("xxx\0yyy", 7, "xxx%cyyy", '\0');
146 test("0x1234abcd ", "%#-12x", 0x1234abcd);
147 test(" 0x1234abcd", "%#12x", 0x1234abcd);
148 test("0|001| 12|+123| 1234|-123|-1234", "%d|%03d|%3d|%+d|% d|%+d|% d", 0, 1, 12, 123, 1234, -123, -1234);
149 test("0|1|1|128|255", "%hhu|%hhu|%hhu|%hhu|%hhu", 0, 1, 257, 128, -1);
150 test("0|1|1|-128|-1", "%hhd|%hhd|%hhd|%hhd|%hhd", 0, 1, 257, 128, -1);
151 test("2015122420151225", "%ho%ho%#ho", 1037, 5282, -11627);
153 * POSIX/C99: »The result of converting zero with an explicit
154 * precision of zero shall be no characters.« Hence the output
155 * from the below test should really be "00|0||| ". However,
156 * the kernel's printf also produces a single 0 in that
157 * case. This test case simply documents the current
160 test("00|0|0|0|0", "%.2d|%.1d|%.0d|%.*d|%1.0d", 0, 0, 0, 0, 0, 0);
161 #ifndef __CHAR_UNSIGNED__
164 * Passing a 'char' to a %02x specifier doesn't do
165 * what was presumably the intention when char is
166 * signed and the value is negative. One must either &
167 * with 0xff or cast to u8.
170 test("0xfffffff0|0xf0|0xf0", "%#02x|%#02x|%#02x", val, val & 0xff, (u8)val);
178 test("", "%s%.0s", "", "123");
179 test("ABCD|abc|123", "%s|%.3s|%.*s", "ABCD", "abcdef", 3, "123456");
180 test("1 | 2|3 | 4|5 ", "%-3s|%3s|%-*s|%*s|%*s", "1", "2", 3, "3", 3, "4", -3, "5");
181 test("1234 ", "%-10.4s", "123456");
182 test(" 1234", "%10.4s", "123456");
184 * POSIX and C99 say that a negative precision (which is only
185 * possible to pass via a * argument) should be treated as if
186 * the precision wasn't present, and that if the precision is
187 * omitted (as in %.s), the precision should be taken to be
188 * 0. However, the kernel's printf behave exactly opposite,
189 * treating a negative precision as 0 and treating an omitted
190 * precision specifier as if no precision was given.
192 * These test cases document the current behaviour; should
193 * anyone ever feel the need to follow the standards more
194 * closely, this can be revisited.
196 test(" ", "%4.*s", -5, "123456");
197 test("123456", "%.s", "123456");
198 test("a||", "%.s|%.0s|%.*s", "a", "b", 0, "c");
199 test("a | | ", "%-3.s|%-3.0s|%-3.*s", "a", "b", 0, "c");
202 #define PLAIN_BUF_SIZE 64 /* leave some space so we don't oops */
204 #if BITS_PER_LONG == 64
207 #define PTR ((void *)0xffff0123456789abUL)
208 #define PTR_STR "ffff0123456789ab"
209 #define PTR_VAL_NO_CRNG "(____ptrval____)"
210 #define ZEROS "00000000" /* hex 32 zero bits */
215 char buf[PLAIN_BUF_SIZE];
218 nchars = snprintf(buf, PLAIN_BUF_SIZE, "%p", PTR);
220 if (nchars != PTR_WIDTH)
223 if (strncmp(buf, PTR_VAL_NO_CRNG, PTR_WIDTH) == 0) {
224 pr_warn("crng possibly not yet initialized. plain 'p' buffer contains \"%s\"",
229 if (strncmp(buf, ZEROS, strlen(ZEROS)) != 0)
238 #define PTR ((void *)0x456789ab)
239 #define PTR_STR "456789ab"
240 #define PTR_VAL_NO_CRNG "(ptrval)"
245 /* Format is implicitly tested for 32 bit machines by plain_hash() */
249 #endif /* BITS_PER_LONG == 64 */
254 char buf[PLAIN_BUF_SIZE];
257 nchars = snprintf(buf, PLAIN_BUF_SIZE, "%p", PTR);
259 if (nchars != PTR_WIDTH)
262 if (strncmp(buf, PTR_VAL_NO_CRNG, PTR_WIDTH) == 0) {
263 pr_warn("crng possibly not yet initialized. plain 'p' buffer contains \"%s\"",
268 if (strncmp(buf, PTR_STR, PTR_WIDTH) == 0)
275 * We can't use test() to test %p because we don't know what output to expect
276 * after an address is hashed.
285 pr_warn("plain 'p' does not appear to be hashed\n");
290 err = plain_format();
292 pr_warn("hashing plain 'p' has unexpected format\n");
305 /* We can't test this without access to kptr_restrict. */
309 struct_resource(void)
326 const char buf[3] = {0xc0, 0xff, 0xee};
328 test("c0 ff ee|c0:ff:ee|c0-ff-ee|c0ffee",
329 "%3ph|%3phC|%3phD|%3phN", buf, buf, buf, buf);
330 test("c0 ff ee|c0:ff:ee|c0-ff-ee|c0ffee",
331 "%*ph|%*phC|%*phD|%*phN", 3, buf, 3, buf, 3, buf, 3, buf);
337 const u8 addr[6] = {0x2d, 0x48, 0xd6, 0xfc, 0x7a, 0x05};
339 test("2d:48:d6:fc:7a:05", "%pM", addr);
340 test("05:7a:fc:d6:48:2d", "%pMR", addr);
341 test("2d-48-d6-fc-7a-05", "%pMF", addr);
342 test("2d48d6fc7a05", "%pm", addr);
343 test("057afcd6482d", "%pmR", addr);
349 struct sockaddr_in sa;
351 sa.sin_family = AF_INET;
352 sa.sin_port = cpu_to_be16(12345);
353 sa.sin_addr.s_addr = cpu_to_be32(0x7f000001);
355 test("127.000.000.001|127.0.0.1", "%pi4|%pI4", &sa.sin_addr, &sa.sin_addr);
356 test("127.000.000.001|127.0.0.1", "%piS|%pIS", &sa, &sa);
357 sa.sin_addr.s_addr = cpu_to_be32(0x01020304);
358 test("001.002.003.004:12345|1.2.3.4:12345", "%piSp|%pISp", &sa, &sa);
376 const char uuid[16] = {0x0, 0x1, 0x2, 0x3, 0x4, 0x5, 0x6, 0x7,
377 0x8, 0x9, 0xa, 0xb, 0xc, 0xd, 0xe, 0xf};
379 test("00010203-0405-0607-0809-0a0b0c0d0e0f", "%pUb", uuid);
380 test("00010203-0405-0607-0809-0A0B0C0D0E0F", "%pUB", uuid);
381 test("03020100-0504-0706-0809-0a0b0c0d0e0f", "%pUl", uuid);
382 test("03020100-0504-0706-0809-0A0B0C0D0E0F", "%pUL", uuid);
385 static struct dentry test_dentry[4] __initdata = {
386 { .d_parent = &test_dentry[0],
387 .d_name = QSTR_INIT(test_dentry[0].d_iname, 3),
389 { .d_parent = &test_dentry[0],
390 .d_name = QSTR_INIT(test_dentry[1].d_iname, 5),
391 .d_iname = "bravo" },
392 { .d_parent = &test_dentry[1],
393 .d_name = QSTR_INIT(test_dentry[2].d_iname, 4),
395 { .d_parent = &test_dentry[2],
396 .d_name = QSTR_INIT(test_dentry[3].d_iname, 5),
397 .d_iname = "romeo" },
403 test("foo", "%pd", &test_dentry[0]);
404 test("foo", "%pd2", &test_dentry[0]);
406 test("romeo", "%pd", &test_dentry[3]);
407 test("alfa/romeo", "%pd2", &test_dentry[3]);
408 test("bravo/alfa/romeo", "%pd3", &test_dentry[3]);
409 test("/bravo/alfa/romeo", "%pd4", &test_dentry[3]);
410 test("/bravo/alfa", "%pd4", &test_dentry[2]);
412 test("bravo/alfa |bravo/alfa ", "%-12pd2|%*pd2", &test_dentry[2], -12, &test_dentry[2]);
413 test(" bravo/alfa| bravo/alfa", "%12pd2|%*pd2", &test_dentry[2], 12, &test_dentry[2]);
417 struct_va_format(void)
429 const int nbits = 1 << 16;
430 unsigned long *bits = kcalloc(BITS_TO_LONGS(nbits), sizeof(long), GFP_KERNEL);
434 bitmap_set(bits, 1, 20);
435 bitmap_set(bits, 60000, 15);
436 test("1-20,60000-60014", "%*pbl", nbits, bits);
443 DECLARE_BITMAP(bits, 20);
444 const int primes[] = {2,3,5,7,11,13,17,19};
447 bitmap_zero(bits, 20);
448 test("00000|00000", "%20pb|%*pb", bits, 20, bits);
449 test("|", "%20pbl|%*pbl", bits, 20, bits);
451 for (i = 0; i < ARRAY_SIZE(primes); ++i)
452 set_bit(primes[i], bits);
453 test("a28ac|a28ac", "%20pb|%*pb", bits, 20, bits);
454 test("2-3,5,7,11,13,17,19|2-3,5,7,11,13,17,19", "%20pbl|%*pbl", bits, 20, bits);
456 bitmap_fill(bits, 20);
457 test("fffff|fffff", "%20pb|%*pb", bits, 20, bits);
458 test("0-19|0-19", "%20pbl|%*pbl", bits, 20, bits);
464 netdev_features(void)
476 test("", "%pGp", &flags);
478 /* Page flags should filter the zone id */
479 flags = 1UL << NR_PAGEFLAGS;
480 test("", "%pGp", &flags);
482 flags |= 1UL << PG_uptodate | 1UL << PG_dirty | 1UL << PG_lru
483 | 1UL << PG_active | 1UL << PG_swapbacked;
484 test("uptodate|dirty|lru|active|swapbacked", "%pGp", &flags);
487 flags = VM_READ | VM_EXEC | VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC
489 test("read|exec|mayread|maywrite|mayexec|denywrite", "%pGv", &flags);
492 test("GFP_TRANSHUGE", "%pGg", &gfp);
494 gfp = GFP_ATOMIC|__GFP_DMA;
495 test("GFP_ATOMIC|GFP_DMA", "%pGg", &gfp);
498 test("__GFP_ATOMIC", "%pGg", &gfp);
500 cmp_buffer = kmalloc(BUF_SIZE, GFP_KERNEL);
504 /* Any flags not translated by the table should remain numeric */
505 gfp = ~__GFP_BITS_MASK;
506 snprintf(cmp_buffer, BUF_SIZE, "%#lx", (unsigned long) gfp);
507 test(cmp_buffer, "%pGg", &gfp);
509 snprintf(cmp_buffer, BUF_SIZE, "__GFP_ATOMIC|%#lx",
510 (unsigned long) gfp);
512 test(cmp_buffer, "%pGg", &gfp);
539 test_printf_init(void)
541 alloced_buffer = kmalloc(BUF_SIZE + 2*PAD_SIZE, GFP_KERNEL);
544 test_buffer = alloced_buffer + PAD_SIZE;
551 kfree(alloced_buffer);
553 if (failed_tests == 0)
554 pr_info("all %u tests passed\n", total_tests);
556 pr_warn("failed %u out of %u tests\n", failed_tests, total_tests);
558 return failed_tests ? -EINVAL : 0;
561 module_init(test_printf_init);
563 MODULE_AUTHOR("Rasmus Villemoes <linux@rasmusvillemoes.dk>");
564 MODULE_LICENSE("GPL");