xref: /linux/lib/tests/string_kunit.c (revision 27b2810a4a3dcd1545ec8bafc82f967eda591c47)
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_strrchr(struct kunit *test)
194 {
195 	size_t buf_size;
196 	char *buf, *s;
197 
198 	buf_size = PAGE_ALIGN(STRING_TEST_MAX_LEN + STRING_TEST_MAX_OFFSET + 1);
199 	buf = vmalloc(buf_size);
200 	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, buf);
201 
202 	memset(buf, 'A', buf_size);
203 
204 	for (size_t offset = 0; offset < STRING_TEST_MAX_OFFSET; offset++) {
205 		for (size_t len = 0; len <= STRING_TEST_MAX_LEN; len++) {
206 			s = buf + buf_size - 1 - offset - len;
207 			s[len] = '\0';
208 
209 			KUNIT_EXPECT_PTR_EQ(test, strrchr(s, 'Z'), NULL);
210 
211 			if (len > 0)
212 				KUNIT_EXPECT_PTR_EQ(test, strrchr(s, 'A'), s + len - 1);
213 			else
214 				KUNIT_EXPECT_PTR_EQ(test, strrchr(s, 'A'), NULL);
215 
216 			s[len] = 'A';
217 		}
218 	}
219 
220 	vfree(buf);
221 }
222 
223 static void string_test_strnchr(struct kunit *test)
224 {
225 	const char *test_string = "abcdefghijkl";
226 	const char *empty_string = "";
227 	char *result;
228 	int i, j;
229 
230 	for (i = 0; i < strlen(test_string) + 1; i++) {
231 		for (j = 0; j < strlen(test_string) + 2; j++) {
232 			result = strnchr(test_string, j, test_string[i]);
233 			if (j <= i) {
234 				KUNIT_ASSERT_NULL_MSG(test, result,
235 					"char:%c i:%d j:%d", 'a' + i, i, j);
236 			} else {
237 				KUNIT_ASSERT_EQ_MSG(test, result - test_string, i,
238 					"char:%c i:%d j:%d", 'a' + i, i, j);
239 			}
240 		}
241 	}
242 
243 	result = strnchr(empty_string, 0, '\0');
244 	KUNIT_ASSERT_NULL(test, result);
245 
246 	result = strnchr(empty_string, 1, '\0');
247 	KUNIT_ASSERT_PTR_EQ(test, result, empty_string);
248 
249 	result = strnchr(empty_string, 1, 'a');
250 	KUNIT_ASSERT_NULL(test, result);
251 
252 	result = strnchr(NULL, 0, '\0');
253 	KUNIT_ASSERT_NULL(test, result);
254 }
255 
256 static void string_test_strspn(struct kunit *test)
257 {
258 	static const struct strspn_test {
259 		const char str[16];
260 		const char accept[16];
261 		const char reject[16];
262 		unsigned a;
263 		unsigned r;
264 	} tests[] = {
265 		{ "foobar", "", "", 0, 6 },
266 		{ "abba", "abc", "ABBA", 4, 4 },
267 		{ "abba", "a", "b", 1, 1 },
268 		{ "", "abc", "abc", 0, 0},
269 	};
270 	const struct strspn_test *s = tests;
271 	size_t i;
272 
273 	for (i = 0; i < ARRAY_SIZE(tests); ++i, ++s) {
274 		KUNIT_ASSERT_EQ_MSG(test, s->a, strspn(s->str, s->accept),
275 			"i:%zu", i);
276 		KUNIT_ASSERT_EQ_MSG(test, s->r, strcspn(s->str, s->reject),
277 			"i:%zu", i);
278 	}
279 }
280 
281 static char strcmp_buffer1[STRCMP_LARGE_BUF_LEN];
282 static char strcmp_buffer2[STRCMP_LARGE_BUF_LEN];
283 
284 static void strcmp_fill_buffers(char fill1, char fill2)
285 {
286 	memset(strcmp_buffer1, fill1, STRCMP_LARGE_BUF_LEN);
287 	memset(strcmp_buffer2, fill2, STRCMP_LARGE_BUF_LEN);
288 	strcmp_buffer1[STRCMP_LARGE_BUF_LEN - 1] = 0;
289 	strcmp_buffer2[STRCMP_LARGE_BUF_LEN - 1] = 0;
290 }
291 
292 static void string_test_strcmp(struct kunit *test)
293 {
294 	/* Equal strings */
295 	STRCMP_TEST_EXPECT_EQUAL(test, strcmp, "Hello, Kernel!", "Hello, Kernel!");
296 	/* First string is lexicographically less than the second */
297 	STRCMP_TEST_EXPECT_LOWER(test, strcmp, "Hello, KUnit!", "Hello, Kernel!");
298 	/* First string is lexicographically larger than the second */
299 	STRCMP_TEST_EXPECT_GREATER(test, strcmp, "Hello, Kernel!", "Hello, KUnit!");
300 	/* Empty string is always lexicographically less than any non-empty string */
301 	STRCMP_TEST_EXPECT_LOWER(test, strcmp, "", "Non-empty string");
302 	/* Two empty strings should be equal */
303 	STRCMP_TEST_EXPECT_EQUAL(test, strcmp, "", "");
304 	/* Compare two strings which have only one char difference */
305 	STRCMP_TEST_EXPECT_LOWER(test, strcmp, "Abacaba", "Abadaba");
306 	/* Compare two strings which have the same prefix*/
307 	STRCMP_TEST_EXPECT_LOWER(test, strcmp, "Just a string", "Just a string and something else");
308 }
309 
310 static void string_test_strcmp_long_strings(struct kunit *test)
311 {
312 	strcmp_fill_buffers('B', 'B');
313 	STRCMP_TEST_EXPECT_EQUAL(test, strcmp, strcmp_buffer1, strcmp_buffer2);
314 
315 	strcmp_buffer1[STRCMP_CHANGE_POINT] = 'A';
316 	STRCMP_TEST_EXPECT_LOWER(test, strcmp, strcmp_buffer1, strcmp_buffer2);
317 
318 	strcmp_buffer1[STRCMP_CHANGE_POINT] = 'C';
319 	STRCMP_TEST_EXPECT_GREATER(test, strcmp, strcmp_buffer1, strcmp_buffer2);
320 }
321 
322 static void string_test_strncmp(struct kunit *test)
323 {
324 	/* Equal strings */
325 	STRCMP_TEST_EXPECT_EQUAL(test, strncmp, "Hello, KUnit!", "Hello, KUnit!", 13);
326 	/* First string is lexicographically less than the second */
327 	STRCMP_TEST_EXPECT_LOWER(test, strncmp, "Hello, KUnit!", "Hello, Kernel!", 13);
328 	/* Result is always 'equal' when count = 0 */
329 	STRCMP_TEST_EXPECT_EQUAL(test, strncmp, "Hello, Kernel!", "Hello, KUnit!", 0);
330 	/* Strings with common prefix are equal if count = length of prefix */
331 	STRCMP_TEST_EXPECT_EQUAL(test, strncmp, "Abacaba", "Abadaba", 3);
332 	/* Strings with common prefix are not equal when count = length of prefix + 1 */
333 	STRCMP_TEST_EXPECT_LOWER(test, strncmp, "Abacaba", "Abadaba", 4);
334 	/* If one string is a prefix of another, the shorter string is lexicographically smaller */
335 	STRCMP_TEST_EXPECT_LOWER(test, strncmp, "Just a string", "Just a string and something else",
336 				 strlen("Just a string and something else"));
337 	/*
338 	 * If one string is a prefix of another, and we check first length
339 	 * of prefix chars, the result is 'equal'
340 	 */
341 	STRCMP_TEST_EXPECT_EQUAL(test, strncmp, "Just a string", "Just a string and something else",
342 				 strlen("Just a string"));
343 }
344 
345 static void string_test_strncmp_long_strings(struct kunit *test)
346 {
347 	strcmp_fill_buffers('B', 'B');
348 	STRCMP_TEST_EXPECT_EQUAL(test, strncmp, strcmp_buffer1,
349 				 strcmp_buffer2, STRCMP_LARGE_BUF_LEN);
350 
351 	strcmp_buffer1[STRCMP_CHANGE_POINT] = 'A';
352 	STRCMP_TEST_EXPECT_LOWER(test, strncmp, strcmp_buffer1,
353 				 strcmp_buffer2, STRCMP_LARGE_BUF_LEN);
354 
355 	strcmp_buffer1[STRCMP_CHANGE_POINT] = 'C';
356 	STRCMP_TEST_EXPECT_GREATER(test, strncmp, strcmp_buffer1,
357 				   strcmp_buffer2, STRCMP_LARGE_BUF_LEN);
358 	/* the strings are equal up to STRCMP_CHANGE_POINT */
359 	STRCMP_TEST_EXPECT_EQUAL(test, strncmp, strcmp_buffer1,
360 				 strcmp_buffer2, STRCMP_CHANGE_POINT);
361 	STRCMP_TEST_EXPECT_GREATER(test, strncmp, strcmp_buffer1,
362 				   strcmp_buffer2, STRCMP_CHANGE_POINT + 1);
363 }
364 
365 static void string_test_strcasecmp(struct kunit *test)
366 {
367 	/* Same strings in different case should be equal */
368 	STRCMP_TEST_EXPECT_EQUAL(test, strcasecmp, "Hello, Kernel!", "HeLLO, KErNeL!");
369 	/* Empty strings should be equal */
370 	STRCMP_TEST_EXPECT_EQUAL(test, strcasecmp, "", "");
371 	/* Despite ascii code for 'a' is larger than ascii code for 'B', 'a' < 'B' */
372 	STRCMP_TEST_EXPECT_LOWER(test, strcasecmp, "a", "B");
373 	STRCMP_TEST_EXPECT_GREATER(test, strcasecmp, "B", "a");
374 	/* Special symbols and numbers should be processed correctly */
375 	STRCMP_TEST_EXPECT_EQUAL(test, strcasecmp, "-+**.1230ghTTT~^", "-+**.1230Ghttt~^");
376 }
377 
378 static void string_test_strcasecmp_long_strings(struct kunit *test)
379 {
380 	strcmp_fill_buffers('b', 'B');
381 	STRCMP_TEST_EXPECT_EQUAL(test, strcasecmp, strcmp_buffer1, strcmp_buffer2);
382 
383 	strcmp_buffer1[STRCMP_CHANGE_POINT] = 'a';
384 	STRCMP_TEST_EXPECT_LOWER(test, strcasecmp, strcmp_buffer1, strcmp_buffer2);
385 
386 	strcmp_buffer1[STRCMP_CHANGE_POINT] = 'C';
387 	STRCMP_TEST_EXPECT_GREATER(test, strcasecmp, strcmp_buffer1, strcmp_buffer2);
388 }
389 
390 static void string_test_strncasecmp(struct kunit *test)
391 {
392 	/* Same strings in different case should be equal */
393 	STRCMP_TEST_EXPECT_EQUAL(test, strncasecmp, "AbAcAbA", "Abacaba", strlen("Abacaba"));
394 	/* strncasecmp should check 'count' chars only */
395 	STRCMP_TEST_EXPECT_EQUAL(test, strncasecmp, "AbaCaBa", "abaCaDa", 5);
396 	STRCMP_TEST_EXPECT_LOWER(test, strncasecmp, "a", "B", 1);
397 	STRCMP_TEST_EXPECT_GREATER(test, strncasecmp, "B", "a", 1);
398 	/* Result is always 'equal' when count = 0 */
399 	STRCMP_TEST_EXPECT_EQUAL(test, strncasecmp, "Abacaba", "Not abacaba", 0);
400 }
401 
402 static void string_test_strncasecmp_long_strings(struct kunit *test)
403 {
404 	strcmp_fill_buffers('b', 'B');
405 	STRCMP_TEST_EXPECT_EQUAL(test, strncasecmp, strcmp_buffer1,
406 				 strcmp_buffer2, STRCMP_LARGE_BUF_LEN);
407 
408 	strcmp_buffer1[STRCMP_CHANGE_POINT] = 'a';
409 	STRCMP_TEST_EXPECT_LOWER(test, strncasecmp, strcmp_buffer1,
410 				 strcmp_buffer2, STRCMP_LARGE_BUF_LEN);
411 
412 	strcmp_buffer1[STRCMP_CHANGE_POINT] = 'C';
413 	STRCMP_TEST_EXPECT_GREATER(test, strncasecmp, strcmp_buffer1,
414 				   strcmp_buffer2, STRCMP_LARGE_BUF_LEN);
415 
416 	STRCMP_TEST_EXPECT_EQUAL(test, strncasecmp, strcmp_buffer1,
417 				 strcmp_buffer2, STRCMP_CHANGE_POINT);
418 	STRCMP_TEST_EXPECT_GREATER(test, strncasecmp, strcmp_buffer1,
419 				   strcmp_buffer2, STRCMP_CHANGE_POINT + 1);
420 }
421 
422 /**
423  * strscpy_check() - Run a specific test case.
424  * @test: KUnit test context pointer
425  * @src: Source string, argument to strscpy_pad()
426  * @count: Size of destination buffer, argument to strscpy_pad()
427  * @expected: Expected return value from call to strscpy_pad()
428  * @chars: Number of characters from the src string expected to be
429  *         written to the dst buffer.
430  * @terminator: 1 if there should be a terminating null byte 0 otherwise.
431  * @pad: Number of pad characters expected (in the tail of dst buffer).
432  *       (@pad does not include the null terminator byte.)
433  *
434  * Calls strscpy_pad() and verifies the return value and state of the
435  * destination buffer after the call returns.
436  */
437 static void strscpy_check(struct kunit *test, char *src, int count,
438 			  int expected, int chars, int terminator, int pad)
439 {
440 	int nr_bytes_poison;
441 	int max_expected;
442 	int max_count;
443 	int written;
444 	char buf[6];
445 	int index, i;
446 	const char POISON = 'z';
447 
448 	KUNIT_ASSERT_TRUE_MSG(test, src != NULL,
449 			      "null source string not supported");
450 
451 	memset(buf, POISON, sizeof(buf));
452 	/* Future proofing test suite, validate args */
453 	max_count = sizeof(buf) - 2; /* Space for null and to verify overflow */
454 	max_expected = count - 1;    /* Space for the null */
455 
456 	KUNIT_ASSERT_LE_MSG(test, count, max_count,
457 		"count (%d) is too big (%d) ... aborting", count, max_count);
458 	KUNIT_EXPECT_LE_MSG(test, expected, max_expected,
459 		"expected (%d) is bigger than can possibly be returned (%d)",
460 		expected, max_expected);
461 
462 	written = strscpy_pad(buf, src, count);
463 	KUNIT_ASSERT_EQ(test, written, expected);
464 
465 	if (count && written == -E2BIG) {
466 		KUNIT_ASSERT_EQ_MSG(test, 0, strncmp(buf, src, count - 1),
467 			"buffer state invalid for -E2BIG");
468 		KUNIT_ASSERT_EQ_MSG(test, buf[count - 1], '\0',
469 			"too big string is not null terminated correctly");
470 	}
471 
472 	for (i = 0; i < chars; i++)
473 		KUNIT_ASSERT_EQ_MSG(test, buf[i], src[i],
474 			"buf[i]==%c != src[i]==%c", buf[i], src[i]);
475 
476 	if (terminator)
477 		KUNIT_ASSERT_EQ_MSG(test, buf[count - 1], '\0',
478 			"string is not null terminated correctly");
479 
480 	for (i = 0; i < pad; i++) {
481 		index = chars + terminator + i;
482 		KUNIT_ASSERT_EQ_MSG(test, buf[index], '\0',
483 			"padding missing at index: %d", i);
484 	}
485 
486 	nr_bytes_poison = sizeof(buf) - chars - terminator - pad;
487 	for (i = 0; i < nr_bytes_poison; i++) {
488 		index = sizeof(buf) - 1 - i; /* Check from the end back */
489 		KUNIT_ASSERT_EQ_MSG(test, buf[index], POISON,
490 			"poison value missing at index: %d", i);
491 	}
492 }
493 
494 static void string_test_strscpy(struct kunit *test)
495 {
496 	char dest[8];
497 
498 	/*
499 	 * strscpy_check() uses a destination buffer of size 6 and needs at
500 	 * least 2 characters spare (one for null and one to check for
501 	 * overflow).  This means we should only call tc() with
502 	 * strings up to a maximum of 4 characters long and 'count'
503 	 * should not exceed 4.  To test with longer strings increase
504 	 * the buffer size in tc().
505 	 */
506 
507 	/* strscpy_check(test, src, count, expected, chars, terminator, pad) */
508 	strscpy_check(test, "a", 0, -E2BIG, 0, 0, 0);
509 	strscpy_check(test, "",  0, -E2BIG, 0, 0, 0);
510 
511 	strscpy_check(test, "a", 1, -E2BIG, 0, 1, 0);
512 	strscpy_check(test, "",  1, 0,	 0, 1, 0);
513 
514 	strscpy_check(test, "ab", 2, -E2BIG, 1, 1, 0);
515 	strscpy_check(test, "a",  2, 1,	  1, 1, 0);
516 	strscpy_check(test, "",   2, 0,	  0, 1, 1);
517 
518 	strscpy_check(test, "abc", 3, -E2BIG, 2, 1, 0);
519 	strscpy_check(test, "ab",  3, 2,	   2, 1, 0);
520 	strscpy_check(test, "a",   3, 1,	   1, 1, 1);
521 	strscpy_check(test, "",    3, 0,	   0, 1, 2);
522 
523 	strscpy_check(test, "abcd", 4, -E2BIG, 3, 1, 0);
524 	strscpy_check(test, "abc",  4, 3,	    3, 1, 0);
525 	strscpy_check(test, "ab",   4, 2,	    2, 1, 1);
526 	strscpy_check(test, "a",    4, 1,	    1, 1, 2);
527 	strscpy_check(test, "",     4, 0,	    0, 1, 3);
528 
529 	/* Compile-time-known source strings. */
530 	KUNIT_EXPECT_EQ(test, strscpy(dest, "", ARRAY_SIZE(dest)), 0);
531 	KUNIT_EXPECT_EQ(test, strscpy(dest, "", 3), 0);
532 	KUNIT_EXPECT_EQ(test, strscpy(dest, "", 1), 0);
533 	KUNIT_EXPECT_EQ(test, strscpy(dest, "", 0), -E2BIG);
534 	KUNIT_EXPECT_EQ(test, strscpy(dest, "Fixed", ARRAY_SIZE(dest)), 5);
535 	KUNIT_EXPECT_EQ(test, strscpy(dest, "Fixed", 3), -E2BIG);
536 	KUNIT_EXPECT_EQ(test, strscpy(dest, "Fixed", 1), -E2BIG);
537 	KUNIT_EXPECT_EQ(test, strscpy(dest, "Fixed", 0), -E2BIG);
538 	KUNIT_EXPECT_EQ(test, strscpy(dest, "This is too long", ARRAY_SIZE(dest)), -E2BIG);
539 }
540 
541 static volatile int unconst;
542 
543 static void string_test_strcat(struct kunit *test)
544 {
545 	char dest[8];
546 
547 	/* Destination is terminated. */
548 	memset(dest, 0, sizeof(dest));
549 	KUNIT_EXPECT_EQ(test, strlen(dest), 0);
550 	/* Empty copy does nothing. */
551 	KUNIT_EXPECT_TRUE(test, strcat(dest, "") == dest);
552 	KUNIT_EXPECT_STREQ(test, dest, "");
553 	/* 4 characters copied in, stops at %NUL. */
554 	KUNIT_EXPECT_TRUE(test, strcat(dest, "four\000123") == dest);
555 	KUNIT_EXPECT_STREQ(test, dest, "four");
556 	KUNIT_EXPECT_EQ(test, dest[5], '\0');
557 	/* 2 more characters copied in okay. */
558 	KUNIT_EXPECT_TRUE(test, strcat(dest, "AB") == dest);
559 	KUNIT_EXPECT_STREQ(test, dest, "fourAB");
560 }
561 
562 static void string_test_strncat(struct kunit *test)
563 {
564 	char dest[8];
565 
566 	/* Destination is terminated. */
567 	memset(dest, 0, sizeof(dest));
568 	KUNIT_EXPECT_EQ(test, strlen(dest), 0);
569 	/* Empty copy of size 0 does nothing. */
570 	KUNIT_EXPECT_TRUE(test, strncat(dest, "", 0 + unconst) == dest);
571 	KUNIT_EXPECT_STREQ(test, dest, "");
572 	/* Empty copy of size 1 does nothing too. */
573 	KUNIT_EXPECT_TRUE(test, strncat(dest, "", 1 + unconst) == dest);
574 	KUNIT_EXPECT_STREQ(test, dest, "");
575 	/* Copy of max 0 characters should do nothing. */
576 	KUNIT_EXPECT_TRUE(test, strncat(dest, "asdf", 0 + unconst) == dest);
577 	KUNIT_EXPECT_STREQ(test, dest, "");
578 
579 	/* 4 characters copied in, even if max is 8. */
580 	KUNIT_EXPECT_TRUE(test, strncat(dest, "four\000123", 8 + unconst) == dest);
581 	KUNIT_EXPECT_STREQ(test, dest, "four");
582 	KUNIT_EXPECT_EQ(test, dest[5], '\0');
583 	KUNIT_EXPECT_EQ(test, dest[6], '\0');
584 	/* 2 characters copied in okay, 2 ignored. */
585 	KUNIT_EXPECT_TRUE(test, strncat(dest, "ABCD", 2 + unconst) == dest);
586 	KUNIT_EXPECT_STREQ(test, dest, "fourAB");
587 }
588 
589 static void string_test_strlcat(struct kunit *test)
590 {
591 	char dest[8] = "";
592 	int len = sizeof(dest) + unconst;
593 
594 	/* Destination is terminated. */
595 	KUNIT_EXPECT_EQ(test, strlen(dest), 0);
596 	/* Empty copy is size 0. */
597 	KUNIT_EXPECT_EQ(test, strlcat(dest, "", len), 0);
598 	KUNIT_EXPECT_STREQ(test, dest, "");
599 	/* Size 1 should keep buffer terminated, report size of source only. */
600 	KUNIT_EXPECT_EQ(test, strlcat(dest, "four", 1 + unconst), 4);
601 	KUNIT_EXPECT_STREQ(test, dest, "");
602 
603 	/* 4 characters copied in. */
604 	KUNIT_EXPECT_EQ(test, strlcat(dest, "four", len), 4);
605 	KUNIT_EXPECT_STREQ(test, dest, "four");
606 	/* 2 characters copied in okay, gets to 6 total. */
607 	KUNIT_EXPECT_EQ(test, strlcat(dest, "AB", len), 6);
608 	KUNIT_EXPECT_STREQ(test, dest, "fourAB");
609 	/* 2 characters ignored if max size (7) reached. */
610 	KUNIT_EXPECT_EQ(test, strlcat(dest, "CD", 7 + unconst), 8);
611 	KUNIT_EXPECT_STREQ(test, dest, "fourAB");
612 	/* 1 of 2 characters skipped, now at true max size. */
613 	KUNIT_EXPECT_EQ(test, strlcat(dest, "EFG", len), 9);
614 	KUNIT_EXPECT_STREQ(test, dest, "fourABE");
615 	/* Everything else ignored, now at full size. */
616 	KUNIT_EXPECT_EQ(test, strlcat(dest, "1234", len), 11);
617 	KUNIT_EXPECT_STREQ(test, dest, "fourABE");
618 }
619 
620 static void string_test_strtomem(struct kunit *test)
621 {
622 	static const char input[sizeof(unsigned long)] = "hi";
623 	static const char truncate[] = "this is too long";
624 	struct {
625 		unsigned long canary1;
626 		unsigned char output[sizeof(unsigned long)] __nonstring;
627 		unsigned long canary2;
628 	} wrap;
629 
630 	memset(&wrap, 0xFF, sizeof(wrap));
631 	KUNIT_EXPECT_EQ_MSG(test, wrap.canary1, ULONG_MAX,
632 			    "bad initial canary value");
633 	KUNIT_EXPECT_EQ_MSG(test, wrap.canary2, ULONG_MAX,
634 			    "bad initial canary value");
635 
636 	/* Check unpadded copy leaves surroundings untouched. */
637 	strtomem(wrap.output, input);
638 	KUNIT_EXPECT_EQ(test, wrap.canary1, ULONG_MAX);
639 	KUNIT_EXPECT_EQ(test, wrap.output[0], input[0]);
640 	KUNIT_EXPECT_EQ(test, wrap.output[1], input[1]);
641 	for (size_t i = 2; i < sizeof(wrap.output); i++)
642 		KUNIT_EXPECT_EQ(test, wrap.output[i], 0xFF);
643 	KUNIT_EXPECT_EQ(test, wrap.canary2, ULONG_MAX);
644 
645 	/* Check truncated copy leaves surroundings untouched. */
646 	memset(&wrap, 0xFF, sizeof(wrap));
647 	strtomem(wrap.output, truncate);
648 	KUNIT_EXPECT_EQ(test, wrap.canary1, ULONG_MAX);
649 	for (size_t i = 0; i < sizeof(wrap.output); i++)
650 		KUNIT_EXPECT_EQ(test, wrap.output[i], truncate[i]);
651 	KUNIT_EXPECT_EQ(test, wrap.canary2, ULONG_MAX);
652 
653 	/* Check padded copy leaves only string padded. */
654 	memset(&wrap, 0xFF, sizeof(wrap));
655 	strtomem_pad(wrap.output, input, 0xAA);
656 	KUNIT_EXPECT_EQ(test, wrap.canary1, ULONG_MAX);
657 	KUNIT_EXPECT_EQ(test, wrap.output[0], input[0]);
658 	KUNIT_EXPECT_EQ(test, wrap.output[1], input[1]);
659 	for (size_t i = 2; i < sizeof(wrap.output); i++)
660 		KUNIT_EXPECT_EQ(test, wrap.output[i], 0xAA);
661 	KUNIT_EXPECT_EQ(test, wrap.canary2, ULONG_MAX);
662 
663 	/* Check truncated padded copy has no padding. */
664 	memset(&wrap, 0xFF, sizeof(wrap));
665 	strtomem(wrap.output, truncate);
666 	KUNIT_EXPECT_EQ(test, wrap.canary1, ULONG_MAX);
667 	for (size_t i = 0; i < sizeof(wrap.output); i++)
668 		KUNIT_EXPECT_EQ(test, wrap.output[i], truncate[i]);
669 	KUNIT_EXPECT_EQ(test, wrap.canary2, ULONG_MAX);
670 }
671 
672 
673 static void string_test_memtostr(struct kunit *test)
674 {
675 	char nonstring[7] __nonstring = { 'a', 'b', 'c', 'd', 'e', 'f', 'g' };
676 	char nonstring_small[3] __nonstring = { 'a', 'b', 'c' };
677 	char dest[sizeof(nonstring) + 1];
678 
679 	/* Copy in a non-NUL-terminated string into exactly right-sized dest. */
680 	KUNIT_EXPECT_EQ(test, sizeof(dest), sizeof(nonstring) + 1);
681 	memset(dest, 'X', sizeof(dest));
682 	memtostr(dest, nonstring);
683 	KUNIT_EXPECT_STREQ(test, dest, "abcdefg");
684 	memset(dest, 'X', sizeof(dest));
685 	memtostr(dest, nonstring_small);
686 	KUNIT_EXPECT_STREQ(test, dest, "abc");
687 	KUNIT_EXPECT_EQ(test, dest[7], 'X');
688 
689 	memset(dest, 'X', sizeof(dest));
690 	memtostr_pad(dest, nonstring);
691 	KUNIT_EXPECT_STREQ(test, dest, "abcdefg");
692 	memset(dest, 'X', sizeof(dest));
693 	memtostr_pad(dest, nonstring_small);
694 	KUNIT_EXPECT_STREQ(test, dest, "abc");
695 	KUNIT_EXPECT_EQ(test, dest[7], '\0');
696 }
697 
698 static void string_test_strends(struct kunit *test)
699 {
700 	KUNIT_EXPECT_TRUE(test, strends("foo-bar", "bar"));
701 	KUNIT_EXPECT_TRUE(test, strends("foo-bar", "-bar"));
702 	KUNIT_EXPECT_TRUE(test, strends("foobar", "foobar"));
703 	KUNIT_EXPECT_TRUE(test, strends("foobar", ""));
704 	KUNIT_EXPECT_FALSE(test, strends("bar", "foobar"));
705 	KUNIT_EXPECT_FALSE(test, strends("", "foo"));
706 	KUNIT_EXPECT_FALSE(test, strends("foobar", "ba"));
707 	KUNIT_EXPECT_TRUE(test, strends("", ""));
708 }
709 
710 static struct kunit_case string_test_cases[] = {
711 	KUNIT_CASE(string_test_memset16),
712 	KUNIT_CASE(string_test_memset32),
713 	KUNIT_CASE(string_test_memset64),
714 	KUNIT_CASE(string_test_strlen),
715 	KUNIT_CASE(string_test_strnlen),
716 	KUNIT_CASE(string_test_strchr),
717 	KUNIT_CASE(string_test_strnchr),
718 	KUNIT_CASE(string_test_strrchr),
719 	KUNIT_CASE(string_test_strspn),
720 	KUNIT_CASE(string_test_strcmp),
721 	KUNIT_CASE(string_test_strcmp_long_strings),
722 	KUNIT_CASE(string_test_strncmp),
723 	KUNIT_CASE(string_test_strncmp_long_strings),
724 	KUNIT_CASE(string_test_strcasecmp),
725 	KUNIT_CASE(string_test_strcasecmp_long_strings),
726 	KUNIT_CASE(string_test_strncasecmp),
727 	KUNIT_CASE(string_test_strncasecmp_long_strings),
728 	KUNIT_CASE(string_test_strscpy),
729 	KUNIT_CASE(string_test_strcat),
730 	KUNIT_CASE(string_test_strncat),
731 	KUNIT_CASE(string_test_strlcat),
732 	KUNIT_CASE(string_test_strtomem),
733 	KUNIT_CASE(string_test_memtostr),
734 	KUNIT_CASE(string_test_strends),
735 	{}
736 };
737 
738 static struct kunit_suite string_test_suite = {
739 	.name = "string",
740 	.test_cases = string_test_cases,
741 };
742 
743 kunit_test_suites(&string_test_suite);
744 
745 MODULE_DESCRIPTION("Test cases for string functions");
746 MODULE_LICENSE("GPL v2");
747