xref: /openbmc/linux/lib/test_printf.c (revision abfbd895) 
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");
363