xref: /linux/lib/tests/string_kunit.c (revision 263dca234e5cc12aa8b434592ceb655538bf4ea4)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Test cases for string functions.
4  */
5 
6 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
7 
8 #include <kunit/test.h>
9 #include <linux/mm.h>
10 #include <linux/module.h>
11 #include <linux/printk.h>
12 #include <linux/slab.h>
13 #include <linux/string.h>
14 #include <linux/vmalloc.h>
15 
16 #define STRCMP_LARGE_BUF_LEN 2048
17 #define STRCMP_CHANGE_POINT 1337
18 #define STRCMP_TEST_EXPECT_EQUAL(test, fn, ...) KUNIT_EXPECT_EQ(test, fn(__VA_ARGS__), 0)
19 #define STRCMP_TEST_EXPECT_LOWER(test, fn, ...) KUNIT_EXPECT_LT(test, fn(__VA_ARGS__), 0)
20 #define STRCMP_TEST_EXPECT_GREATER(test, fn, ...) KUNIT_EXPECT_GT(test, fn(__VA_ARGS__), 0)
21 
22 #define STRING_TEST_MAX_LEN	128
23 #define STRING_TEST_MAX_OFFSET	16
24 
25 static void string_test_memset16(struct kunit *test)
26 {
27 	unsigned i, j, k;
28 	u16 v, *p;
29 
30 	p = kunit_kzalloc(test, 256 * 2 * 2, GFP_KERNEL);
31 	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, p);
32 
33 	for (i = 0; i < 256; i++) {
34 		for (j = 0; j < 256; j++) {
35 			memset(p, 0xa1, 256 * 2 * sizeof(v));
36 			memset16(p + i, 0xb1b2, j);
37 			for (k = 0; k < 512; k++) {
38 				v = p[k];
39 				if (k < i) {
40 					KUNIT_ASSERT_EQ_MSG(test, v, 0xa1a1,
41 						"i:%d j:%d k:%d", i, j, k);
42 				} else if (k < i + j) {
43 					KUNIT_ASSERT_EQ_MSG(test, v, 0xb1b2,
44 						"i:%d j:%d k:%d", i, j, k);
45 				} else {
46 					KUNIT_ASSERT_EQ_MSG(test, v, 0xa1a1,
47 						"i:%d j:%d k:%d", i, j, k);
48 				}
49 			}
50 		}
51 	}
52 }
53 
54 static void string_test_memset32(struct kunit *test)
55 {
56 	unsigned i, j, k;
57 	u32 v, *p;
58 
59 	p = kunit_kzalloc(test, 256 * 2 * 4, GFP_KERNEL);
60 	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, p);
61 
62 	for (i = 0; i < 256; i++) {
63 		for (j = 0; j < 256; j++) {
64 			memset(p, 0xa1, 256 * 2 * sizeof(v));
65 			memset32(p + i, 0xb1b2b3b4, j);
66 			for (k = 0; k < 512; k++) {
67 				v = p[k];
68 				if (k < i) {
69 					KUNIT_ASSERT_EQ_MSG(test, v, 0xa1a1a1a1,
70 						"i:%d j:%d k:%d", i, j, k);
71 				} else if (k < i + j) {
72 					KUNIT_ASSERT_EQ_MSG(test, v, 0xb1b2b3b4,
73 						"i:%d j:%d k:%d", i, j, k);
74 				} else {
75 					KUNIT_ASSERT_EQ_MSG(test, v, 0xa1a1a1a1,
76 						"i:%d j:%d k:%d", i, j, k);
77 				}
78 			}
79 		}
80 	}
81 }
82 
83 static void string_test_memset64(struct kunit *test)
84 {
85 	unsigned i, j, k;
86 	u64 v, *p;
87 
88 	p = kunit_kzalloc(test, 256 * 2 * 8, GFP_KERNEL);
89 	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, p);
90 
91 	for (i = 0; i < 256; i++) {
92 		for (j = 0; j < 256; j++) {
93 			memset(p, 0xa1, 256 * 2 * sizeof(v));
94 			memset64(p + i, 0xb1b2b3b4b5b6b7b8ULL, j);
95 			for (k = 0; k < 512; k++) {
96 				v = p[k];
97 				if (k < i) {
98 					KUNIT_ASSERT_EQ_MSG(test, v, 0xa1a1a1a1a1a1a1a1ULL,
99 						"i:%d j:%d k:%d", i, j, k);
100 				} else if (k < i + j) {
101 					KUNIT_ASSERT_EQ_MSG(test, v, 0xb1b2b3b4b5b6b7b8ULL,
102 						"i:%d j:%d k:%d", i, j, k);
103 				} else {
104 					KUNIT_ASSERT_EQ_MSG(test, v, 0xa1a1a1a1a1a1a1a1ULL,
105 						"i:%d j:%d k:%d", i, j, k);
106 				}
107 			}
108 		}
109 	}
110 }
111 
112 static void string_test_strlen(struct kunit *test)
113 {
114 	size_t buf_size;
115 	char *buf, *s;
116 
117 	buf_size = PAGE_ALIGN(STRING_TEST_MAX_LEN + STRING_TEST_MAX_OFFSET + 1);
118 	buf = vmalloc(buf_size);
119 	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, buf);
120 
121 	memset(buf, 'A', buf_size);
122 
123 	for (size_t offset = 0; offset < STRING_TEST_MAX_OFFSET; offset++) {
124 		for (size_t len = 0; len <= STRING_TEST_MAX_LEN; len++) {
125 			s = buf + buf_size - 1 - offset - len;
126 			s[len] = '\0';
127 			KUNIT_EXPECT_EQ_MSG(test, strlen(s), len,
128 				"offset:%zu len:%zu", offset, len);
129 			s[len] = 'A';
130 		}
131 	}
132 
133 	vfree(buf);
134 }
135 
136 static void string_test_strnlen(struct kunit *test)
137 {
138 	size_t buf_size;
139 	char *buf, *s;
140 
141 	buf_size = PAGE_ALIGN(STRING_TEST_MAX_LEN + STRING_TEST_MAX_OFFSET + 1);
142 	buf = vmalloc(buf_size);
143 	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, buf);
144 
145 	memset(buf, 'A', buf_size);
146 
147 	for (size_t offset = 0; offset < STRING_TEST_MAX_OFFSET; offset++) {
148 		for (size_t len = 0; len <= STRING_TEST_MAX_LEN; len++) {
149 			s = buf + buf_size - 1 - offset - len;
150 			s[len] = '\0';
151 
152 			if (len > 0)
153 				KUNIT_EXPECT_EQ(test, strnlen(s, len - 1), len - 1);
154 			if (len > 1)
155 				KUNIT_EXPECT_EQ(test, strnlen(s, len - 2), len - 2);
156 
157 			KUNIT_EXPECT_EQ(test, strnlen(s, len), len);
158 
159 			KUNIT_EXPECT_EQ(test, strnlen(s, len + 1), len);
160 			KUNIT_EXPECT_EQ(test, strnlen(s, len + 2), len);
161 			KUNIT_EXPECT_EQ(test, strnlen(s, len + 10), len);
162 
163 			s[len] = 'A';
164 		}
165 	}
166 
167 	vfree(buf);
168 }
169 
170 static void string_test_strchr(struct kunit *test)
171 {
172 	const char *test_string = "abcdefghijkl";
173 	const char *empty_string = "";
174 	char *result;
175 	int i;
176 
177 	for (i = 0; i < strlen(test_string) + 1; i++) {
178 		result = strchr(test_string, test_string[i]);
179 		KUNIT_ASSERT_EQ_MSG(test, result - test_string, i,
180 				    "char:%c", 'a' + i);
181 	}
182 
183 	result = strchr(empty_string, '\0');
184 	KUNIT_ASSERT_PTR_EQ(test, result, empty_string);
185 
186 	result = strchr(empty_string, 'a');
187 	KUNIT_ASSERT_NULL(test, result);
188 
189 	result = strchr(test_string, 'z');
190 	KUNIT_ASSERT_NULL(test, result);
191 }
192 
193 static void string_test_strnchr(struct kunit *test)
194 {
195 	const char *test_string = "abcdefghijkl";
196 	const char *empty_string = "";
197 	char *result;
198 	int i, j;
199 
200 	for (i = 0; i < strlen(test_string) + 1; i++) {
201 		for (j = 0; j < strlen(test_string) + 2; j++) {
202 			result = strnchr(test_string, j, test_string[i]);
203 			if (j <= i) {
204 				KUNIT_ASSERT_NULL_MSG(test, result,
205 					"char:%c i:%d j:%d", 'a' + i, i, j);
206 			} else {
207 				KUNIT_ASSERT_EQ_MSG(test, result - test_string, i,
208 					"char:%c i:%d j:%d", 'a' + i, i, j);
209 			}
210 		}
211 	}
212 
213 	result = strnchr(empty_string, 0, '\0');
214 	KUNIT_ASSERT_NULL(test, result);
215 
216 	result = strnchr(empty_string, 1, '\0');
217 	KUNIT_ASSERT_PTR_EQ(test, result, empty_string);
218 
219 	result = strnchr(empty_string, 1, 'a');
220 	KUNIT_ASSERT_NULL(test, result);
221 
222 	result = strnchr(NULL, 0, '\0');
223 	KUNIT_ASSERT_NULL(test, result);
224 }
225 
226 static void string_test_strspn(struct kunit *test)
227 {
228 	static const struct strspn_test {
229 		const char str[16];
230 		const char accept[16];
231 		const char reject[16];
232 		unsigned a;
233 		unsigned r;
234 	} tests[] = {
235 		{ "foobar", "", "", 0, 6 },
236 		{ "abba", "abc", "ABBA", 4, 4 },
237 		{ "abba", "a", "b", 1, 1 },
238 		{ "", "abc", "abc", 0, 0},
239 	};
240 	const struct strspn_test *s = tests;
241 	size_t i;
242 
243 	for (i = 0; i < ARRAY_SIZE(tests); ++i, ++s) {
244 		KUNIT_ASSERT_EQ_MSG(test, s->a, strspn(s->str, s->accept),
245 			"i:%zu", i);
246 		KUNIT_ASSERT_EQ_MSG(test, s->r, strcspn(s->str, s->reject),
247 			"i:%zu", i);
248 	}
249 }
250 
251 static char strcmp_buffer1[STRCMP_LARGE_BUF_LEN];
252 static char strcmp_buffer2[STRCMP_LARGE_BUF_LEN];
253 
254 static void strcmp_fill_buffers(char fill1, char fill2)
255 {
256 	memset(strcmp_buffer1, fill1, STRCMP_LARGE_BUF_LEN);
257 	memset(strcmp_buffer2, fill2, STRCMP_LARGE_BUF_LEN);
258 	strcmp_buffer1[STRCMP_LARGE_BUF_LEN - 1] = 0;
259 	strcmp_buffer2[STRCMP_LARGE_BUF_LEN - 1] = 0;
260 }
261 
262 static void string_test_strcmp(struct kunit *test)
263 {
264 	/* Equal strings */
265 	STRCMP_TEST_EXPECT_EQUAL(test, strcmp, "Hello, Kernel!", "Hello, Kernel!");
266 	/* First string is lexicographically less than the second */
267 	STRCMP_TEST_EXPECT_LOWER(test, strcmp, "Hello, KUnit!", "Hello, Kernel!");
268 	/* First string is lexicographically larger than the second */
269 	STRCMP_TEST_EXPECT_GREATER(test, strcmp, "Hello, Kernel!", "Hello, KUnit!");
270 	/* Empty string is always lexicographically less than any non-empty string */
271 	STRCMP_TEST_EXPECT_LOWER(test, strcmp, "", "Non-empty string");
272 	/* Two empty strings should be equal */
273 	STRCMP_TEST_EXPECT_EQUAL(test, strcmp, "", "");
274 	/* Compare two strings which have only one char difference */
275 	STRCMP_TEST_EXPECT_LOWER(test, strcmp, "Abacaba", "Abadaba");
276 	/* Compare two strings which have the same prefix*/
277 	STRCMP_TEST_EXPECT_LOWER(test, strcmp, "Just a string", "Just a string and something else");
278 }
279 
280 static void string_test_strcmp_long_strings(struct kunit *test)
281 {
282 	strcmp_fill_buffers('B', 'B');
283 	STRCMP_TEST_EXPECT_EQUAL(test, strcmp, strcmp_buffer1, strcmp_buffer2);
284 
285 	strcmp_buffer1[STRCMP_CHANGE_POINT] = 'A';
286 	STRCMP_TEST_EXPECT_LOWER(test, strcmp, strcmp_buffer1, strcmp_buffer2);
287 
288 	strcmp_buffer1[STRCMP_CHANGE_POINT] = 'C';
289 	STRCMP_TEST_EXPECT_GREATER(test, strcmp, strcmp_buffer1, strcmp_buffer2);
290 }
291 
292 static void string_test_strncmp(struct kunit *test)
293 {
294 	/* Equal strings */
295 	STRCMP_TEST_EXPECT_EQUAL(test, strncmp, "Hello, KUnit!", "Hello, KUnit!", 13);
296 	/* First string is lexicographically less than the second */
297 	STRCMP_TEST_EXPECT_LOWER(test, strncmp, "Hello, KUnit!", "Hello, Kernel!", 13);
298 	/* Result is always 'equal' when count = 0 */
299 	STRCMP_TEST_EXPECT_EQUAL(test, strncmp, "Hello, Kernel!", "Hello, KUnit!", 0);
300 	/* Strings with common prefix are equal if count = length of prefix */
301 	STRCMP_TEST_EXPECT_EQUAL(test, strncmp, "Abacaba", "Abadaba", 3);
302 	/* Strings with common prefix are not equal when count = length of prefix + 1 */
303 	STRCMP_TEST_EXPECT_LOWER(test, strncmp, "Abacaba", "Abadaba", 4);
304 	/* If one string is a prefix of another, the shorter string is lexicographically smaller */
305 	STRCMP_TEST_EXPECT_LOWER(test, strncmp, "Just a string", "Just a string and something else",
306 				 strlen("Just a string and something else"));
307 	/*
308 	 * If one string is a prefix of another, and we check first length
309 	 * of prefix chars, the result is 'equal'
310 	 */
311 	STRCMP_TEST_EXPECT_EQUAL(test, strncmp, "Just a string", "Just a string and something else",
312 				 strlen("Just a string"));
313 }
314 
315 static void string_test_strncmp_long_strings(struct kunit *test)
316 {
317 	strcmp_fill_buffers('B', 'B');
318 	STRCMP_TEST_EXPECT_EQUAL(test, strncmp, strcmp_buffer1,
319 				 strcmp_buffer2, STRCMP_LARGE_BUF_LEN);
320 
321 	strcmp_buffer1[STRCMP_CHANGE_POINT] = 'A';
322 	STRCMP_TEST_EXPECT_LOWER(test, strncmp, strcmp_buffer1,
323 				 strcmp_buffer2, STRCMP_LARGE_BUF_LEN);
324 
325 	strcmp_buffer1[STRCMP_CHANGE_POINT] = 'C';
326 	STRCMP_TEST_EXPECT_GREATER(test, strncmp, strcmp_buffer1,
327 				   strcmp_buffer2, STRCMP_LARGE_BUF_LEN);
328 	/* the strings are equal up to STRCMP_CHANGE_POINT */
329 	STRCMP_TEST_EXPECT_EQUAL(test, strncmp, strcmp_buffer1,
330 				 strcmp_buffer2, STRCMP_CHANGE_POINT);
331 	STRCMP_TEST_EXPECT_GREATER(test, strncmp, strcmp_buffer1,
332 				   strcmp_buffer2, STRCMP_CHANGE_POINT + 1);
333 }
334 
335 static void string_test_strcasecmp(struct kunit *test)
336 {
337 	/* Same strings in different case should be equal */
338 	STRCMP_TEST_EXPECT_EQUAL(test, strcasecmp, "Hello, Kernel!", "HeLLO, KErNeL!");
339 	/* Empty strings should be equal */
340 	STRCMP_TEST_EXPECT_EQUAL(test, strcasecmp, "", "");
341 	/* Despite ascii code for 'a' is larger than ascii code for 'B', 'a' < 'B' */
342 	STRCMP_TEST_EXPECT_LOWER(test, strcasecmp, "a", "B");
343 	STRCMP_TEST_EXPECT_GREATER(test, strcasecmp, "B", "a");
344 	/* Special symbols and numbers should be processed correctly */
345 	STRCMP_TEST_EXPECT_EQUAL(test, strcasecmp, "-+**.1230ghTTT~^", "-+**.1230Ghttt~^");
346 }
347 
348 static void string_test_strcasecmp_long_strings(struct kunit *test)
349 {
350 	strcmp_fill_buffers('b', 'B');
351 	STRCMP_TEST_EXPECT_EQUAL(test, strcasecmp, strcmp_buffer1, strcmp_buffer2);
352 
353 	strcmp_buffer1[STRCMP_CHANGE_POINT] = 'a';
354 	STRCMP_TEST_EXPECT_LOWER(test, strcasecmp, strcmp_buffer1, strcmp_buffer2);
355 
356 	strcmp_buffer1[STRCMP_CHANGE_POINT] = 'C';
357 	STRCMP_TEST_EXPECT_GREATER(test, strcasecmp, strcmp_buffer1, strcmp_buffer2);
358 }
359 
360 static void string_test_strncasecmp(struct kunit *test)
361 {
362 	/* Same strings in different case should be equal */
363 	STRCMP_TEST_EXPECT_EQUAL(test, strncasecmp, "AbAcAbA", "Abacaba", strlen("Abacaba"));
364 	/* strncasecmp should check 'count' chars only */
365 	STRCMP_TEST_EXPECT_EQUAL(test, strncasecmp, "AbaCaBa", "abaCaDa", 5);
366 	STRCMP_TEST_EXPECT_LOWER(test, strncasecmp, "a", "B", 1);
367 	STRCMP_TEST_EXPECT_GREATER(test, strncasecmp, "B", "a", 1);
368 	/* Result is always 'equal' when count = 0 */
369 	STRCMP_TEST_EXPECT_EQUAL(test, strncasecmp, "Abacaba", "Not abacaba", 0);
370 }
371 
372 static void string_test_strncasecmp_long_strings(struct kunit *test)
373 {
374 	strcmp_fill_buffers('b', 'B');
375 	STRCMP_TEST_EXPECT_EQUAL(test, strncasecmp, strcmp_buffer1,
376 				 strcmp_buffer2, STRCMP_LARGE_BUF_LEN);
377 
378 	strcmp_buffer1[STRCMP_CHANGE_POINT] = 'a';
379 	STRCMP_TEST_EXPECT_LOWER(test, strncasecmp, strcmp_buffer1,
380 				 strcmp_buffer2, STRCMP_LARGE_BUF_LEN);
381 
382 	strcmp_buffer1[STRCMP_CHANGE_POINT] = 'C';
383 	STRCMP_TEST_EXPECT_GREATER(test, strncasecmp, strcmp_buffer1,
384 				   strcmp_buffer2, STRCMP_LARGE_BUF_LEN);
385 
386 	STRCMP_TEST_EXPECT_EQUAL(test, strncasecmp, strcmp_buffer1,
387 				 strcmp_buffer2, STRCMP_CHANGE_POINT);
388 	STRCMP_TEST_EXPECT_GREATER(test, strncasecmp, strcmp_buffer1,
389 				   strcmp_buffer2, STRCMP_CHANGE_POINT + 1);
390 }
391 
392 /**
393  * strscpy_check() - Run a specific test case.
394  * @test: KUnit test context pointer
395  * @src: Source string, argument to strscpy_pad()
396  * @count: Size of destination buffer, argument to strscpy_pad()
397  * @expected: Expected return value from call to strscpy_pad()
398  * @chars: Number of characters from the src string expected to be
399  *         written to the dst buffer.
400  * @terminator: 1 if there should be a terminating null byte 0 otherwise.
401  * @pad: Number of pad characters expected (in the tail of dst buffer).
402  *       (@pad does not include the null terminator byte.)
403  *
404  * Calls strscpy_pad() and verifies the return value and state of the
405  * destination buffer after the call returns.
406  */
407 static void strscpy_check(struct kunit *test, char *src, int count,
408 			  int expected, int chars, int terminator, int pad)
409 {
410 	int nr_bytes_poison;
411 	int max_expected;
412 	int max_count;
413 	int written;
414 	char buf[6];
415 	int index, i;
416 	const char POISON = 'z';
417 
418 	KUNIT_ASSERT_TRUE_MSG(test, src != NULL,
419 			      "null source string not supported");
420 
421 	memset(buf, POISON, sizeof(buf));
422 	/* Future proofing test suite, validate args */
423 	max_count = sizeof(buf) - 2; /* Space for null and to verify overflow */
424 	max_expected = count - 1;    /* Space for the null */
425 
426 	KUNIT_ASSERT_LE_MSG(test, count, max_count,
427 		"count (%d) is too big (%d) ... aborting", count, max_count);
428 	KUNIT_EXPECT_LE_MSG(test, expected, max_expected,
429 		"expected (%d) is bigger than can possibly be returned (%d)",
430 		expected, max_expected);
431 
432 	written = strscpy_pad(buf, src, count);
433 	KUNIT_ASSERT_EQ(test, written, expected);
434 
435 	if (count && written == -E2BIG) {
436 		KUNIT_ASSERT_EQ_MSG(test, 0, strncmp(buf, src, count - 1),
437 			"buffer state invalid for -E2BIG");
438 		KUNIT_ASSERT_EQ_MSG(test, buf[count - 1], '\0',
439 			"too big string is not null terminated correctly");
440 	}
441 
442 	for (i = 0; i < chars; i++)
443 		KUNIT_ASSERT_EQ_MSG(test, buf[i], src[i],
444 			"buf[i]==%c != src[i]==%c", buf[i], src[i]);
445 
446 	if (terminator)
447 		KUNIT_ASSERT_EQ_MSG(test, buf[count - 1], '\0',
448 			"string is not null terminated correctly");
449 
450 	for (i = 0; i < pad; i++) {
451 		index = chars + terminator + i;
452 		KUNIT_ASSERT_EQ_MSG(test, buf[index], '\0',
453 			"padding missing at index: %d", i);
454 	}
455 
456 	nr_bytes_poison = sizeof(buf) - chars - terminator - pad;
457 	for (i = 0; i < nr_bytes_poison; i++) {
458 		index = sizeof(buf) - 1 - i; /* Check from the end back */
459 		KUNIT_ASSERT_EQ_MSG(test, buf[index], POISON,
460 			"poison value missing at index: %d", i);
461 	}
462 }
463 
464 static void string_test_strscpy(struct kunit *test)
465 {
466 	char dest[8];
467 
468 	/*
469 	 * strscpy_check() uses a destination buffer of size 6 and needs at
470 	 * least 2 characters spare (one for null and one to check for
471 	 * overflow).  This means we should only call tc() with
472 	 * strings up to a maximum of 4 characters long and 'count'
473 	 * should not exceed 4.  To test with longer strings increase
474 	 * the buffer size in tc().
475 	 */
476 
477 	/* strscpy_check(test, src, count, expected, chars, terminator, pad) */
478 	strscpy_check(test, "a", 0, -E2BIG, 0, 0, 0);
479 	strscpy_check(test, "",  0, -E2BIG, 0, 0, 0);
480 
481 	strscpy_check(test, "a", 1, -E2BIG, 0, 1, 0);
482 	strscpy_check(test, "",  1, 0,	 0, 1, 0);
483 
484 	strscpy_check(test, "ab", 2, -E2BIG, 1, 1, 0);
485 	strscpy_check(test, "a",  2, 1,	  1, 1, 0);
486 	strscpy_check(test, "",   2, 0,	  0, 1, 1);
487 
488 	strscpy_check(test, "abc", 3, -E2BIG, 2, 1, 0);
489 	strscpy_check(test, "ab",  3, 2,	   2, 1, 0);
490 	strscpy_check(test, "a",   3, 1,	   1, 1, 1);
491 	strscpy_check(test, "",    3, 0,	   0, 1, 2);
492 
493 	strscpy_check(test, "abcd", 4, -E2BIG, 3, 1, 0);
494 	strscpy_check(test, "abc",  4, 3,	    3, 1, 0);
495 	strscpy_check(test, "ab",   4, 2,	    2, 1, 1);
496 	strscpy_check(test, "a",    4, 1,	    1, 1, 2);
497 	strscpy_check(test, "",     4, 0,	    0, 1, 3);
498 
499 	/* Compile-time-known source strings. */
500 	KUNIT_EXPECT_EQ(test, strscpy(dest, "", ARRAY_SIZE(dest)), 0);
501 	KUNIT_EXPECT_EQ(test, strscpy(dest, "", 3), 0);
502 	KUNIT_EXPECT_EQ(test, strscpy(dest, "", 1), 0);
503 	KUNIT_EXPECT_EQ(test, strscpy(dest, "", 0), -E2BIG);
504 	KUNIT_EXPECT_EQ(test, strscpy(dest, "Fixed", ARRAY_SIZE(dest)), 5);
505 	KUNIT_EXPECT_EQ(test, strscpy(dest, "Fixed", 3), -E2BIG);
506 	KUNIT_EXPECT_EQ(test, strscpy(dest, "Fixed", 1), -E2BIG);
507 	KUNIT_EXPECT_EQ(test, strscpy(dest, "Fixed", 0), -E2BIG);
508 	KUNIT_EXPECT_EQ(test, strscpy(dest, "This is too long", ARRAY_SIZE(dest)), -E2BIG);
509 }
510 
511 static volatile int unconst;
512 
513 static void string_test_strcat(struct kunit *test)
514 {
515 	char dest[8];
516 
517 	/* Destination is terminated. */
518 	memset(dest, 0, sizeof(dest));
519 	KUNIT_EXPECT_EQ(test, strlen(dest), 0);
520 	/* Empty copy does nothing. */
521 	KUNIT_EXPECT_TRUE(test, strcat(dest, "") == dest);
522 	KUNIT_EXPECT_STREQ(test, dest, "");
523 	/* 4 characters copied in, stops at %NUL. */
524 	KUNIT_EXPECT_TRUE(test, strcat(dest, "four\000123") == dest);
525 	KUNIT_EXPECT_STREQ(test, dest, "four");
526 	KUNIT_EXPECT_EQ(test, dest[5], '\0');
527 	/* 2 more characters copied in okay. */
528 	KUNIT_EXPECT_TRUE(test, strcat(dest, "AB") == dest);
529 	KUNIT_EXPECT_STREQ(test, dest, "fourAB");
530 }
531 
532 static void string_test_strncat(struct kunit *test)
533 {
534 	char dest[8];
535 
536 	/* Destination is terminated. */
537 	memset(dest, 0, sizeof(dest));
538 	KUNIT_EXPECT_EQ(test, strlen(dest), 0);
539 	/* Empty copy of size 0 does nothing. */
540 	KUNIT_EXPECT_TRUE(test, strncat(dest, "", 0 + unconst) == dest);
541 	KUNIT_EXPECT_STREQ(test, dest, "");
542 	/* Empty copy of size 1 does nothing too. */
543 	KUNIT_EXPECT_TRUE(test, strncat(dest, "", 1 + unconst) == dest);
544 	KUNIT_EXPECT_STREQ(test, dest, "");
545 	/* Copy of max 0 characters should do nothing. */
546 	KUNIT_EXPECT_TRUE(test, strncat(dest, "asdf", 0 + unconst) == dest);
547 	KUNIT_EXPECT_STREQ(test, dest, "");
548 
549 	/* 4 characters copied in, even if max is 8. */
550 	KUNIT_EXPECT_TRUE(test, strncat(dest, "four\000123", 8 + unconst) == dest);
551 	KUNIT_EXPECT_STREQ(test, dest, "four");
552 	KUNIT_EXPECT_EQ(test, dest[5], '\0');
553 	KUNIT_EXPECT_EQ(test, dest[6], '\0');
554 	/* 2 characters copied in okay, 2 ignored. */
555 	KUNIT_EXPECT_TRUE(test, strncat(dest, "ABCD", 2 + unconst) == dest);
556 	KUNIT_EXPECT_STREQ(test, dest, "fourAB");
557 }
558 
559 static void string_test_strlcat(struct kunit *test)
560 {
561 	char dest[8] = "";
562 	int len = sizeof(dest) + unconst;
563 
564 	/* Destination is terminated. */
565 	KUNIT_EXPECT_EQ(test, strlen(dest), 0);
566 	/* Empty copy is size 0. */
567 	KUNIT_EXPECT_EQ(test, strlcat(dest, "", len), 0);
568 	KUNIT_EXPECT_STREQ(test, dest, "");
569 	/* Size 1 should keep buffer terminated, report size of source only. */
570 	KUNIT_EXPECT_EQ(test, strlcat(dest, "four", 1 + unconst), 4);
571 	KUNIT_EXPECT_STREQ(test, dest, "");
572 
573 	/* 4 characters copied in. */
574 	KUNIT_EXPECT_EQ(test, strlcat(dest, "four", len), 4);
575 	KUNIT_EXPECT_STREQ(test, dest, "four");
576 	/* 2 characters copied in okay, gets to 6 total. */
577 	KUNIT_EXPECT_EQ(test, strlcat(dest, "AB", len), 6);
578 	KUNIT_EXPECT_STREQ(test, dest, "fourAB");
579 	/* 2 characters ignored if max size (7) reached. */
580 	KUNIT_EXPECT_EQ(test, strlcat(dest, "CD", 7 + unconst), 8);
581 	KUNIT_EXPECT_STREQ(test, dest, "fourAB");
582 	/* 1 of 2 characters skipped, now at true max size. */
583 	KUNIT_EXPECT_EQ(test, strlcat(dest, "EFG", len), 9);
584 	KUNIT_EXPECT_STREQ(test, dest, "fourABE");
585 	/* Everything else ignored, now at full size. */
586 	KUNIT_EXPECT_EQ(test, strlcat(dest, "1234", len), 11);
587 	KUNIT_EXPECT_STREQ(test, dest, "fourABE");
588 }
589 
590 static void string_test_strtomem(struct kunit *test)
591 {
592 	static const char input[sizeof(unsigned long)] = "hi";
593 	static const char truncate[] = "this is too long";
594 	struct {
595 		unsigned long canary1;
596 		unsigned char output[sizeof(unsigned long)] __nonstring;
597 		unsigned long canary2;
598 	} wrap;
599 
600 	memset(&wrap, 0xFF, sizeof(wrap));
601 	KUNIT_EXPECT_EQ_MSG(test, wrap.canary1, ULONG_MAX,
602 			    "bad initial canary value");
603 	KUNIT_EXPECT_EQ_MSG(test, wrap.canary2, ULONG_MAX,
604 			    "bad initial canary value");
605 
606 	/* Check unpadded copy leaves surroundings untouched. */
607 	strtomem(wrap.output, input);
608 	KUNIT_EXPECT_EQ(test, wrap.canary1, ULONG_MAX);
609 	KUNIT_EXPECT_EQ(test, wrap.output[0], input[0]);
610 	KUNIT_EXPECT_EQ(test, wrap.output[1], input[1]);
611 	for (size_t i = 2; i < sizeof(wrap.output); i++)
612 		KUNIT_EXPECT_EQ(test, wrap.output[i], 0xFF);
613 	KUNIT_EXPECT_EQ(test, wrap.canary2, ULONG_MAX);
614 
615 	/* Check truncated copy leaves surroundings untouched. */
616 	memset(&wrap, 0xFF, sizeof(wrap));
617 	strtomem(wrap.output, truncate);
618 	KUNIT_EXPECT_EQ(test, wrap.canary1, ULONG_MAX);
619 	for (size_t i = 0; i < sizeof(wrap.output); i++)
620 		KUNIT_EXPECT_EQ(test, wrap.output[i], truncate[i]);
621 	KUNIT_EXPECT_EQ(test, wrap.canary2, ULONG_MAX);
622 
623 	/* Check padded copy leaves only string padded. */
624 	memset(&wrap, 0xFF, sizeof(wrap));
625 	strtomem_pad(wrap.output, input, 0xAA);
626 	KUNIT_EXPECT_EQ(test, wrap.canary1, ULONG_MAX);
627 	KUNIT_EXPECT_EQ(test, wrap.output[0], input[0]);
628 	KUNIT_EXPECT_EQ(test, wrap.output[1], input[1]);
629 	for (size_t i = 2; i < sizeof(wrap.output); i++)
630 		KUNIT_EXPECT_EQ(test, wrap.output[i], 0xAA);
631 	KUNIT_EXPECT_EQ(test, wrap.canary2, ULONG_MAX);
632 
633 	/* Check truncated padded copy has no padding. */
634 	memset(&wrap, 0xFF, sizeof(wrap));
635 	strtomem(wrap.output, truncate);
636 	KUNIT_EXPECT_EQ(test, wrap.canary1, ULONG_MAX);
637 	for (size_t i = 0; i < sizeof(wrap.output); i++)
638 		KUNIT_EXPECT_EQ(test, wrap.output[i], truncate[i]);
639 	KUNIT_EXPECT_EQ(test, wrap.canary2, ULONG_MAX);
640 }
641 
642 
643 static void string_test_memtostr(struct kunit *test)
644 {
645 	char nonstring[7] __nonstring = { 'a', 'b', 'c', 'd', 'e', 'f', 'g' };
646 	char nonstring_small[3] __nonstring = { 'a', 'b', 'c' };
647 	char dest[sizeof(nonstring) + 1];
648 
649 	/* Copy in a non-NUL-terminated string into exactly right-sized dest. */
650 	KUNIT_EXPECT_EQ(test, sizeof(dest), sizeof(nonstring) + 1);
651 	memset(dest, 'X', sizeof(dest));
652 	memtostr(dest, nonstring);
653 	KUNIT_EXPECT_STREQ(test, dest, "abcdefg");
654 	memset(dest, 'X', sizeof(dest));
655 	memtostr(dest, nonstring_small);
656 	KUNIT_EXPECT_STREQ(test, dest, "abc");
657 	KUNIT_EXPECT_EQ(test, dest[7], 'X');
658 
659 	memset(dest, 'X', sizeof(dest));
660 	memtostr_pad(dest, nonstring);
661 	KUNIT_EXPECT_STREQ(test, dest, "abcdefg");
662 	memset(dest, 'X', sizeof(dest));
663 	memtostr_pad(dest, nonstring_small);
664 	KUNIT_EXPECT_STREQ(test, dest, "abc");
665 	KUNIT_EXPECT_EQ(test, dest[7], '\0');
666 }
667 
668 static void string_test_strends(struct kunit *test)
669 {
670 	KUNIT_EXPECT_TRUE(test, strends("foo-bar", "bar"));
671 	KUNIT_EXPECT_TRUE(test, strends("foo-bar", "-bar"));
672 	KUNIT_EXPECT_TRUE(test, strends("foobar", "foobar"));
673 	KUNIT_EXPECT_TRUE(test, strends("foobar", ""));
674 	KUNIT_EXPECT_FALSE(test, strends("bar", "foobar"));
675 	KUNIT_EXPECT_FALSE(test, strends("", "foo"));
676 	KUNIT_EXPECT_FALSE(test, strends("foobar", "ba"));
677 	KUNIT_EXPECT_TRUE(test, strends("", ""));
678 }
679 
680 static struct kunit_case string_test_cases[] = {
681 	KUNIT_CASE(string_test_memset16),
682 	KUNIT_CASE(string_test_memset32),
683 	KUNIT_CASE(string_test_memset64),
684 	KUNIT_CASE(string_test_strlen),
685 	KUNIT_CASE(string_test_strnlen),
686 	KUNIT_CASE(string_test_strchr),
687 	KUNIT_CASE(string_test_strnchr),
688 	KUNIT_CASE(string_test_strspn),
689 	KUNIT_CASE(string_test_strcmp),
690 	KUNIT_CASE(string_test_strcmp_long_strings),
691 	KUNIT_CASE(string_test_strncmp),
692 	KUNIT_CASE(string_test_strncmp_long_strings),
693 	KUNIT_CASE(string_test_strcasecmp),
694 	KUNIT_CASE(string_test_strcasecmp_long_strings),
695 	KUNIT_CASE(string_test_strncasecmp),
696 	KUNIT_CASE(string_test_strncasecmp_long_strings),
697 	KUNIT_CASE(string_test_strscpy),
698 	KUNIT_CASE(string_test_strcat),
699 	KUNIT_CASE(string_test_strncat),
700 	KUNIT_CASE(string_test_strlcat),
701 	KUNIT_CASE(string_test_strtomem),
702 	KUNIT_CASE(string_test_memtostr),
703 	KUNIT_CASE(string_test_strends),
704 	{}
705 };
706 
707 static struct kunit_suite string_test_suite = {
708 	.name = "string",
709 	.test_cases = string_test_cases,
710 };
711 
712 kunit_test_suites(&string_test_suite);
713 
714 MODULE_DESCRIPTION("Test cases for string functions");
715 MODULE_LICENSE("GPL v2");
716