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/socket.h>
22 #define PTR1 ((void*)0x01234567)
23 #define PTR2 ((void*)(long)(int)0xfedcba98)
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"
32 #define PTR1_ZEROES "0"
33 #define PTR1_SPACES " "
34 #define PTR1_STR "1234567"
35 #define PTR2_STR "fedcba98"
38 #define PTR_WIDTH_STR stringify(PTR_WIDTH)
40 static unsigned total_tests __initdata;
41 static unsigned failed_tests __initdata;
42 static char *test_buffer __initdata;
43 static char *alloced_buffer __initdata;
45 static int __printf(4, 0) __init
46 do_test(int bufsize, const char *expect, int elen,
47 const char *fmt, va_list ap)
54 memset(alloced_buffer, FILL_CHAR, BUF_SIZE + 2*PAD_SIZE);
56 ret = vsnprintf(test_buffer, bufsize, fmt, aq);
60 pr_warn("vsnprintf(buf, %d, \"%s\", ...) returned %d, expected %d\n",
61 bufsize, fmt, ret, elen);
65 if (memchr_inv(alloced_buffer, FILL_CHAR, PAD_SIZE)) {
66 pr_warn("vsnprintf(buf, %d, \"%s\", ...) wrote before buffer\n", bufsize, fmt);
71 if (memchr_inv(test_buffer, FILL_CHAR, BUF_SIZE + PAD_SIZE)) {
72 pr_warn("vsnprintf(buf, 0, \"%s\", ...) wrote to buffer\n",
79 written = min(bufsize-1, elen);
80 if (test_buffer[written]) {
81 pr_warn("vsnprintf(buf, %d, \"%s\", ...) did not nul-terminate buffer\n",
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",
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);
100 static void __printf(3, 4) __init
101 __test(const char *expect, int elen, const char *fmt, ...)
107 if (elen >= BUF_SIZE) {
108 pr_err("error in test suite: expected output length %d too long. Format was '%s'.\n",
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.
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);
128 p = kvasprintf(GFP_KERNEL, fmt, ap);
131 if (memcmp(p, expect, elen+1)) {
132 pr_warn("kvasprintf(..., \"%s\", ...) returned '%s', expected '%s'\n",
141 #define test(expect, fmt, ...) \
142 __test(expect, strlen(expect), fmt, ##__VA_ARGS__)
147 /* Work around annoying "warning: zero-length gnu_printf format string". */
151 test("100%", "100%%");
152 test("xxx%yyy", "xxx%cyyy", '%');
153 __test("xxx\0yyy", 7, "xxx%cyyy", '\0');
159 test("0x1234abcd ", "%#-12x", 0x1234abcd);
160 test(" 0x1234abcd", "%#12x", 0x1234abcd);
161 test("0|001| 12|+123| 1234|-123|-1234", "%d|%03d|%3d|%+d|% d|%+d|% d", 0, 1, 12, 123, 1234, -123, -1234);
162 test("0|1|1|128|255", "%hhu|%hhu|%hhu|%hhu|%hhu", 0, 1, 257, 128, -1);
163 test("0|1|1|-128|-1", "%hhd|%hhd|%hhd|%hhd|%hhd", 0, 1, 257, 128, -1);
164 test("2015122420151225", "%ho%ho%#ho", 1037, 5282, -11627);
166 * POSIX/C99: »The result of converting zero with an explicit
167 * precision of zero shall be no characters.« Hence the output
168 * from the below test should really be "00|0||| ". However,
169 * the kernel's printf also produces a single 0 in that
170 * case. This test case simply documents the current
173 test("00|0|0|0|0", "%.2d|%.1d|%.0d|%.*d|%1.0d", 0, 0, 0, 0, 0, 0);
174 #ifndef __CHAR_UNSIGNED__
177 * Passing a 'char' to a %02x specifier doesn't do
178 * what was presumably the intention when char is
179 * signed and the value is negative. One must either &
180 * with 0xff or cast to u8.
183 test("0xfffffff0|0xf0|0xf0", "%#02x|%#02x|%#02x", val, val & 0xff, (u8)val);
191 test("", "%s%.0s", "", "123");
192 test("ABCD|abc|123", "%s|%.3s|%.*s", "ABCD", "abcdef", 3, "123456");
193 test("1 | 2|3 | 4|5 ", "%-3s|%3s|%-*s|%*s|%*s", "1", "2", 3, "3", 3, "4", -3, "5");
194 test("1234 ", "%-10.4s", "123456");
195 test(" 1234", "%10.4s", "123456");
197 * POSIX and C99 say that a negative precision (which is only
198 * possible to pass via a * argument) should be treated as if
199 * the precision wasn't present, and that if the precision is
200 * omitted (as in %.s), the precision should be taken to be
201 * 0. However, the kernel's printf behave exactly opposite,
202 * treating a negative precision as 0 and treating an omitted
203 * precision specifier as if no precision was given.
205 * These test cases document the current behaviour; should
206 * anyone ever feel the need to follow the standards more
207 * closely, this can be revisited.
209 test(" ", "%4.*s", -5, "123456");
210 test("123456", "%.s", "123456");
211 test("a||", "%.s|%.0s|%.*s", "a", "b", 0, "c");
212 test("a | | ", "%-3.s|%-3.0s|%-3.*s", "a", "b", 0, "c");
218 test(PTR1_ZEROES PTR1_STR " " PTR2_STR, "%p %p", PTR1, PTR2);
220 * The field width is overloaded for some %p extensions to
221 * pass another piece of information. For plain pointers, the
222 * behaviour is slightly odd: One cannot pass either the 0
223 * flag nor a precision to %p without gcc complaining, and if
224 * one explicitly gives a field width, the number is no longer
227 test("|" PTR1_STR PTR1_SPACES " | " PTR1_SPACES PTR1_STR "|",
228 "|%-*p|%*p|", PTR_WIDTH+2, PTR1, PTR_WIDTH+2, PTR1);
229 test("|" PTR2_STR " | " PTR2_STR "|",
230 "|%-*p|%*p|", PTR_WIDTH+2, PTR2, PTR_WIDTH+2, PTR2);
233 * Unrecognized %p extensions are treated as plain %p, but the
234 * alphanumeric suffix is ignored (that is, does not occur in
237 test("|"PTR1_ZEROES PTR1_STR"|", "|%p0y|", PTR1);
238 test("|"PTR2_STR"|", "|%p0y|", PTR2);
252 struct_resource(void)
269 const char buf[3] = {0xc0, 0xff, 0xee};
271 test("c0 ff ee|c0:ff:ee|c0-ff-ee|c0ffee",
272 "%3ph|%3phC|%3phD|%3phN", buf, buf, buf, buf);
273 test("c0 ff ee|c0:ff:ee|c0-ff-ee|c0ffee",
274 "%*ph|%*phC|%*phD|%*phN", 3, buf, 3, buf, 3, buf, 3, buf);
280 const u8 addr[6] = {0x2d, 0x48, 0xd6, 0xfc, 0x7a, 0x05};
282 test("2d:48:d6:fc:7a:05", "%pM", addr);
283 test("05:7a:fc:d6:48:2d", "%pMR", addr);
284 test("2d-48-d6-fc-7a-05", "%pMF", addr);
285 test("2d48d6fc7a05", "%pm", addr);
286 test("057afcd6482d", "%pmR", addr);
292 struct sockaddr_in sa;
294 sa.sin_family = AF_INET;
295 sa.sin_port = cpu_to_be16(12345);
296 sa.sin_addr.s_addr = cpu_to_be32(0x7f000001);
298 test("127.000.000.001|127.0.0.1", "%pi4|%pI4", &sa.sin_addr, &sa.sin_addr);
299 test("127.000.000.001|127.0.0.1", "%piS|%pIS", &sa, &sa);
300 sa.sin_addr.s_addr = cpu_to_be32(0x01020304);
301 test("001.002.003.004:12345|1.2.3.4:12345", "%piSp|%pISp", &sa, &sa);
319 const char uuid[16] = {0x0, 0x1, 0x2, 0x3, 0x4, 0x5, 0x6, 0x7,
320 0x8, 0x9, 0xa, 0xb, 0xc, 0xd, 0xe, 0xf};
322 test("00010203-0405-0607-0809-0a0b0c0d0e0f", "%pUb", uuid);
323 test("00010203-0405-0607-0809-0A0B0C0D0E0F", "%pUB", uuid);
324 test("03020100-0504-0706-0809-0a0b0c0d0e0f", "%pUl", uuid);
325 test("03020100-0504-0706-0809-0A0B0C0D0E0F", "%pUL", uuid);
334 struct_va_format(void)
346 DECLARE_BITMAP(bits, 20);
347 const int primes[] = {2,3,5,7,11,13,17,19};
350 bitmap_zero(bits, 20);
351 test("00000|00000", "%20pb|%*pb", bits, 20, bits);
352 test("|", "%20pbl|%*pbl", bits, 20, bits);
354 for (i = 0; i < ARRAY_SIZE(primes); ++i)
355 set_bit(primes[i], bits);
356 test("a28ac|a28ac", "%20pb|%*pb", bits, 20, bits);
357 test("2-3,5,7,11,13,17,19|2-3,5,7,11,13,17,19", "%20pbl|%*pbl", bits, 20, bits);
359 bitmap_fill(bits, 20);
360 test("fffff|fffff", "%20pb|%*pb", bits, 20, bits);
361 test("0-19|0-19", "%20pbl|%*pbl", bits, 20, bits);
365 netdev_features(void)
390 test_printf_init(void)
392 alloced_buffer = kmalloc(BUF_SIZE + 2*PAD_SIZE, GFP_KERNEL);
395 test_buffer = alloced_buffer + PAD_SIZE;
402 kfree(alloced_buffer);
404 if (failed_tests == 0)
405 pr_info("all %u tests passed\n", total_tests);
407 pr_warn("failed %u out of %u tests\n", failed_tests, total_tests);
409 return failed_tests ? -EINVAL : 0;
412 module_init(test_printf_init);
414 MODULE_AUTHOR("Rasmus Villemoes <linux@rasmusvillemoes.dk>");
415 MODULE_LICENSE("GPL");