1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * KUnit test for struct string_stream.
4 *
5 * Copyright (C) 2019, Google LLC.
6 * Author: Brendan Higgins <brendanhiggins@google.com>
7 */
8
9 #include <kunit/static_stub.h>
10 #include <kunit/test.h>
11 #include <linux/ktime.h>
12 #include <linux/slab.h>
13 #include <linux/timekeeping.h>
14
15 #include "string-stream.h"
16
17 struct string_stream_test_priv {
18 /* For testing resource-managed free. */
19 struct string_stream *expected_free_stream;
20 bool stream_was_freed;
21 bool stream_free_again;
22 };
23
24 /* Avoids a cast warning if kfree() is passed direct to kunit_add_action(). */
25 KUNIT_DEFINE_ACTION_WRAPPER(kfree_wrapper, kfree, const void *);
26
27 /* Avoids a cast warning if string_stream_destroy() is passed direct to kunit_add_action(). */
28 KUNIT_DEFINE_ACTION_WRAPPER(cleanup_raw_stream, string_stream_destroy, struct string_stream *);
29
30 static char *get_concatenated_string(struct kunit *test, struct string_stream *stream)
31 {
32 char *str = string_stream_get_string(stream);
33
34 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, str);
35 kunit_add_action(test, kfree_wrapper, (void *)str);
36
37 return str;
38 }
39
40 /* Managed string_stream object is initialized correctly. */
41 static void string_stream_managed_init_test(struct kunit *test)
42 {
43 struct string_stream *stream;
44
45 /* Resource-managed initialization. */
46 stream = kunit_alloc_string_stream(test, GFP_KERNEL);
47 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, stream);
48
49 KUNIT_EXPECT_EQ(test, stream->length, 0);
50 KUNIT_EXPECT_TRUE(test, list_empty(&stream->fragments));
51 KUNIT_EXPECT_TRUE(test, (stream->gfp == GFP_KERNEL));
52 KUNIT_EXPECT_FALSE(test, stream->append_newlines);
53 KUNIT_EXPECT_TRUE(test, string_stream_is_empty(stream));
54 }
55
56 /* Unmanaged string_stream object is initialized correctly. */
57 static void string_stream_unmanaged_init_test(struct kunit *test)
58 {
59 struct string_stream *stream;
60
61 stream = alloc_string_stream(GFP_KERNEL);
62 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, stream);
63 kunit_add_action(test, cleanup_raw_stream, stream);
64
65 KUNIT_EXPECT_EQ(test, stream->length, 0);
66 KUNIT_EXPECT_TRUE(test, list_empty(&stream->fragments));
67 KUNIT_EXPECT_TRUE(test, (stream->gfp == GFP_KERNEL));
68 KUNIT_EXPECT_FALSE(test, stream->append_newlines);
69
70 KUNIT_EXPECT_TRUE(test, string_stream_is_empty(stream));
71 }
72
73 static void string_stream_destroy_stub(struct string_stream *stream)
74 {
75 struct kunit *fake_test = kunit_get_current_test();
76 struct string_stream_test_priv *priv = fake_test->priv;
77
78 /* The kunit could own string_streams other than the one we are testing. */
79 if (stream == priv->expected_free_stream) {
80 if (priv->stream_was_freed)
81 priv->stream_free_again = true;
82 else
83 priv->stream_was_freed = true;
84 }
85
86 /*
87 * Calling string_stream_destroy() will only call this function again
88 * because the redirection stub is still active.
89 * Avoid calling deactivate_static_stub() or changing current->kunit_test
90 * during cleanup.
91 */
92 string_stream_clear(stream);
93 kfree(stream);
94 }
95
96 /* kunit_free_string_stream() calls string_stream_desrtoy() */
97 static void string_stream_managed_free_test(struct kunit *test)
98 {
99 struct string_stream_test_priv *priv = test->priv;
100
101 priv->expected_free_stream = NULL;
102 priv->stream_was_freed = false;
103 priv->stream_free_again = false;
104
105 kunit_activate_static_stub(test,
106 string_stream_destroy,
107 string_stream_destroy_stub);
108
109 priv->expected_free_stream = kunit_alloc_string_stream(test, GFP_KERNEL);
110 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, priv->expected_free_stream);
111
112 /* This should call the stub function. */
113 kunit_free_string_stream(test, priv->expected_free_stream);
114
115 KUNIT_EXPECT_TRUE(test, priv->stream_was_freed);
116 KUNIT_EXPECT_FALSE(test, priv->stream_free_again);
117 }
118
119 /* string_stream object is freed when test is cleaned up. */
120 static void string_stream_resource_free_test(struct kunit *test)
121 {
122 struct string_stream_test_priv *priv = test->priv;
123 struct kunit *fake_test;
124
125 fake_test = kunit_kzalloc(test, sizeof(*fake_test), GFP_KERNEL);
126 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, fake_test);
127
128 kunit_init_test(fake_test, "string_stream_fake_test", NULL);
129 fake_test->priv = priv;
130
131 /*
132 * Activate stub before creating string_stream so the
133 * string_stream will be cleaned up first.
134 */
135 priv->expected_free_stream = NULL;
136 priv->stream_was_freed = false;
137 priv->stream_free_again = false;
138
139 kunit_activate_static_stub(fake_test,
140 string_stream_destroy,
141 string_stream_destroy_stub);
142
143 priv->expected_free_stream = kunit_alloc_string_stream(fake_test, GFP_KERNEL);
144 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, priv->expected_free_stream);
145
146 /* Set current->kunit_test to fake_test so the static stub will be called. */
147 current->kunit_test = fake_test;
148
149 /* Cleanup test - the stub function should be called */
150 kunit_cleanup(fake_test);
151
152 /* Set current->kunit_test back to current test. */
153 current->kunit_test = test;
154
155 KUNIT_EXPECT_TRUE(test, priv->stream_was_freed);
156 KUNIT_EXPECT_FALSE(test, priv->stream_free_again);
157 }
158
159 /*
160 * Add a series of lines to a string_stream. Check that all lines
161 * appear in the correct order and no characters are dropped.
162 */
163 static void string_stream_line_add_test(struct kunit *test)
164 {
165 struct string_stream *stream;
166 char line[60];
167 char *concat_string, *pos, *string_end;
168 size_t len, total_len;
169 int num_lines, i;
170
171 stream = kunit_alloc_string_stream(test, GFP_KERNEL);
172 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, stream);
173
174 /* Add series of sequence numbered lines */
175 total_len = 0;
176 for (i = 0; i < 100; ++i) {
177 len = snprintf(line, sizeof(line),
178 "The quick brown fox jumps over the lazy penguin %d\n", i);
179
180 /* Sanity-check that our test string isn't truncated */
181 KUNIT_ASSERT_LT(test, len, sizeof(line));
182
183 string_stream_add(stream, line);
184 total_len += len;
185 }
186 num_lines = i;
187
188 concat_string = get_concatenated_string(test, stream);
189 KUNIT_EXPECT_NOT_ERR_OR_NULL(test, concat_string);
190 KUNIT_EXPECT_EQ(test, strlen(concat_string), total_len);
191
192 /*
193 * Split the concatenated string at the newlines and check that
194 * all the original added strings are present.
195 */
196 pos = concat_string;
197 for (i = 0; i < num_lines; ++i) {
198 string_end = strchr(pos, '\n');
199 KUNIT_EXPECT_NOT_NULL(test, string_end);
200
201 /* Convert to NULL-terminated string */
202 *string_end = '\0';
203
204 snprintf(line, sizeof(line),
205 "The quick brown fox jumps over the lazy penguin %d", i);
206 KUNIT_EXPECT_STREQ(test, pos, line);
207
208 pos = string_end + 1;
209 }
210
211 /* There shouldn't be any more data after this */
212 KUNIT_EXPECT_EQ(test, strlen(pos), 0);
213 }
214
215 /* Add a series of lines of variable length to a string_stream. */
216 static void string_stream_variable_length_line_test(struct kunit *test)
217 {
218 static const char line[] =
219 "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ"
220 " 0123456789!$%^&*()_-+={}[]:;@'~#<>,.?/|";
221 struct string_stream *stream;
222 struct rnd_state rnd;
223 char *concat_string, *pos, *string_end;
224 size_t offset, total_len;
225 int num_lines, i;
226
227 stream = kunit_alloc_string_stream(test, GFP_KERNEL);
228 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, stream);
229
230 /*
231 * Log many lines of varying lengths until we have created
232 * many fragments.
233 * The "randomness" must be repeatable.
234 */
235 prandom_seed_state(&rnd, 3141592653589793238ULL);
236 total_len = 0;
237 for (i = 0; i < 100; ++i) {
238 offset = prandom_u32_state(&rnd) % (sizeof(line) - 1);
239 string_stream_add(stream, "%s\n", &line[offset]);
240 total_len += sizeof(line) - offset;
241 }
242 num_lines = i;
243
244 concat_string = get_concatenated_string(test, stream);
245 KUNIT_EXPECT_NOT_ERR_OR_NULL(test, concat_string);
246 KUNIT_EXPECT_EQ(test, strlen(concat_string), total_len);
247
248 /*
249 * Split the concatenated string at the newlines and check that
250 * all the original added strings are present.
251 */
252 prandom_seed_state(&rnd, 3141592653589793238ULL);
253 pos = concat_string;
254 for (i = 0; i < num_lines; ++i) {
255 string_end = strchr(pos, '\n');
256 KUNIT_EXPECT_NOT_NULL(test, string_end);
257
258 /* Convert to NULL-terminated string */
259 *string_end = '\0';
260
261 offset = prandom_u32_state(&rnd) % (sizeof(line) - 1);
262 KUNIT_EXPECT_STREQ(test, pos, &line[offset]);
263
264 pos = string_end + 1;
265 }
266
267 /* There shouldn't be any more data after this */
268 KUNIT_EXPECT_EQ(test, strlen(pos), 0);
269 }
270
271 /* Appending the content of one string stream to another. */
272 static void string_stream_append_test(struct kunit *test)
273 {
274 static const char * const strings_1[] = {
275 "one", "two", "three", "four", "five", "six",
276 "seven", "eight", "nine", "ten",
277 };
278 static const char * const strings_2[] = {
279 "Apple", "Pear", "Orange", "Banana", "Grape", "Apricot",
280 };
281 struct string_stream *stream_1, *stream_2;
282 const char *stream1_content_before_append, *stream_2_content;
283 char *combined_content;
284 size_t combined_length;
285 int i;
286
287 stream_1 = kunit_alloc_string_stream(test, GFP_KERNEL);
288 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, stream_1);
289
290 stream_2 = kunit_alloc_string_stream(test, GFP_KERNEL);
291 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, stream_2);
292
293 /* Append content of empty stream to empty stream */
294 string_stream_append(stream_1, stream_2);
295 KUNIT_EXPECT_EQ(test, strlen(get_concatenated_string(test, stream_1)), 0);
296
297 /* Add some data to stream_1 */
298 for (i = 0; i < ARRAY_SIZE(strings_1); ++i)
299 string_stream_add(stream_1, "%s\n", strings_1[i]);
300
301 stream1_content_before_append = get_concatenated_string(test, stream_1);
302
303 /* Append content of empty stream to non-empty stream */
304 string_stream_append(stream_1, stream_2);
305 KUNIT_EXPECT_STREQ(test, get_concatenated_string(test, stream_1),
306 stream1_content_before_append);
307
308 /* Add some data to stream_2 */
309 for (i = 0; i < ARRAY_SIZE(strings_2); ++i)
310 string_stream_add(stream_2, "%s\n", strings_2[i]);
311
312 /* Append content of non-empty stream to non-empty stream */
313 string_stream_append(stream_1, stream_2);
314
315 /*
316 * End result should be the original content of stream_1 plus
317 * the content of stream_2.
318 */
319 stream_2_content = get_concatenated_string(test, stream_2);
320 combined_length = strlen(stream1_content_before_append) + strlen(stream_2_content);
321 combined_length++; /* for terminating \0 */
322 combined_content = kunit_kmalloc(test, combined_length, GFP_KERNEL);
323 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, combined_content);
324 snprintf(combined_content, combined_length, "%s%s",
325 stream1_content_before_append, stream_2_content);
326
327 KUNIT_EXPECT_STREQ(test, get_concatenated_string(test, stream_1), combined_content);
328
329 /* Append content of non-empty stream to empty stream */
330 kunit_free_string_stream(test, stream_1);
331
332 stream_1 = kunit_alloc_string_stream(test, GFP_KERNEL);
333 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, stream_1);
334
335 string_stream_append(stream_1, stream_2);
336 KUNIT_EXPECT_STREQ(test, get_concatenated_string(test, stream_1), stream_2_content);
337 }
338
339 /* Appending the content of one string stream to one with auto-newlining. */
340 static void string_stream_append_auto_newline_test(struct kunit *test)
341 {
342 struct string_stream *stream_1, *stream_2;
343
344 /* Stream 1 has newline appending enabled */
345 stream_1 = kunit_alloc_string_stream(test, GFP_KERNEL);
346 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, stream_1);
347 string_stream_set_append_newlines(stream_1, true);
348 KUNIT_EXPECT_TRUE(test, stream_1->append_newlines);
349
350 /* Stream 2 does not append newlines */
351 stream_2 = kunit_alloc_string_stream(test, GFP_KERNEL);
352 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, stream_2);
353
354 /* Appending a stream with a newline should not add another newline */
355 string_stream_add(stream_1, "Original string\n");
356 string_stream_add(stream_2, "Appended content\n");
357 string_stream_add(stream_2, "More stuff\n");
358 string_stream_append(stream_1, stream_2);
359 KUNIT_EXPECT_STREQ(test, get_concatenated_string(test, stream_1),
360 "Original string\nAppended content\nMore stuff\n");
361
362 kunit_free_string_stream(test, stream_2);
363 stream_2 = kunit_alloc_string_stream(test, GFP_KERNEL);
364 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, stream_2);
365
366 /*
367 * Appending a stream without newline should add a final newline.
368 * The appended string_stream is treated as a single string so newlines
369 * should not be inserted between fragments.
370 */
371 string_stream_add(stream_2, "Another");
372 string_stream_add(stream_2, "And again");
373 string_stream_append(stream_1, stream_2);
374 KUNIT_EXPECT_STREQ(test, get_concatenated_string(test, stream_1),
375 "Original string\nAppended content\nMore stuff\nAnotherAnd again\n");
376 }
377
378 /* Adding an empty string should not create a fragment. */
379 static void string_stream_append_empty_string_test(struct kunit *test)
380 {
381 struct string_stream *stream;
382 int original_frag_count;
383
384 stream = kunit_alloc_string_stream(test, GFP_KERNEL);
385 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, stream);
386
387 /* Formatted empty string */
388 string_stream_add(stream, "%s", "");
389 KUNIT_EXPECT_TRUE(test, string_stream_is_empty(stream));
390 KUNIT_EXPECT_TRUE(test, list_empty(&stream->fragments));
391
392 /* Adding an empty string to a non-empty stream */
393 string_stream_add(stream, "Add this line");
394 original_frag_count = list_count_nodes(&stream->fragments);
395
396 string_stream_add(stream, "%s", "");
397 KUNIT_EXPECT_EQ(test, list_count_nodes(&stream->fragments), original_frag_count);
398 KUNIT_EXPECT_STREQ(test, get_concatenated_string(test, stream), "Add this line");
399 }
400
401 /* Adding strings without automatic newline appending */
402 static void string_stream_no_auto_newline_test(struct kunit *test)
403 {
404 struct string_stream *stream;
405
406 stream = kunit_alloc_string_stream(test, GFP_KERNEL);
407 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, stream);
408
409 /*
410 * Add some strings with and without newlines. All formatted newlines
411 * should be preserved. It should not add any extra newlines.
412 */
413 string_stream_add(stream, "One");
414 string_stream_add(stream, "Two\n");
415 string_stream_add(stream, "%s\n", "Three");
416 string_stream_add(stream, "%s", "Four\n");
417 string_stream_add(stream, "Five\n%s", "Six");
418 string_stream_add(stream, "Seven\n\n");
419 string_stream_add(stream, "Eight");
420 KUNIT_EXPECT_STREQ(test, get_concatenated_string(test, stream),
421 "OneTwo\nThree\nFour\nFive\nSixSeven\n\nEight");
422 }
423
424 /* Adding strings with automatic newline appending */
425 static void string_stream_auto_newline_test(struct kunit *test)
426 {
427 struct string_stream *stream;
428
429 stream = kunit_alloc_string_stream(test, GFP_KERNEL);
430 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, stream);
431
432 string_stream_set_append_newlines(stream, true);
433 KUNIT_EXPECT_TRUE(test, stream->append_newlines);
434
435 /*
436 * Add some strings with and without newlines. Newlines should
437 * be appended to lines that do not end with \n, but newlines
438 * resulting from the formatting should not be changed.
439 */
440 string_stream_add(stream, "One");
441 string_stream_add(stream, "Two\n");
442 string_stream_add(stream, "%s\n", "Three");
443 string_stream_add(stream, "%s", "Four\n");
444 string_stream_add(stream, "Five\n%s", "Six");
445 string_stream_add(stream, "Seven\n\n");
446 string_stream_add(stream, "Eight");
447 KUNIT_EXPECT_STREQ(test, get_concatenated_string(test, stream),
448 "One\nTwo\nThree\nFour\nFive\nSix\nSeven\n\nEight\n");
449 }
450
451 /*
452 * This doesn't actually "test" anything. It reports time taken
453 * and memory used for logging a large number of lines.
454 */
455 static void string_stream_performance_test(struct kunit *test)
456 {
457 struct string_stream_fragment *frag_container;
458 struct string_stream *stream;
459 char test_line[101];
460 ktime_t start_time, end_time;
461 size_t len, bytes_requested, actual_bytes_used, total_string_length;
462 int offset, i;
463
464 stream = kunit_alloc_string_stream(test, GFP_KERNEL);
465 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, stream);
466
467 memset(test_line, 'x', sizeof(test_line) - 1);
468 test_line[sizeof(test_line) - 1] = '\0';
469
470 start_time = ktime_get();
471 for (i = 0; i < 10000; i++) {
472 offset = i % (sizeof(test_line) - 1);
473 string_stream_add(stream, "%s: %d\n", &test_line[offset], i);
474 }
475 end_time = ktime_get();
476
477 /*
478 * Calculate memory used. This doesn't include invisible
479 * overhead due to kernel allocator fragment size rounding.
480 */
481 bytes_requested = sizeof(*stream);
482 actual_bytes_used = ksize(stream);
483 total_string_length = 0;
484
485 list_for_each_entry(frag_container, &stream->fragments, node) {
486 bytes_requested += sizeof(*frag_container);
487 actual_bytes_used += ksize(frag_container);
488
489 len = strlen(frag_container->fragment);
490 total_string_length += len;
491 bytes_requested += len + 1; /* +1 for '\0' */
492 actual_bytes_used += ksize(frag_container->fragment);
493 }
494
495 kunit_info(test, "Time elapsed: %lld us\n",
496 ktime_us_delta(end_time, start_time));
497 kunit_info(test, "Total string length: %zu\n", total_string_length);
498 kunit_info(test, "Bytes requested: %zu\n", bytes_requested);
499 kunit_info(test, "Actual bytes allocated: %zu\n", actual_bytes_used);
500 }
501
502 static int string_stream_test_init(struct kunit *test)
503 {
504 struct string_stream_test_priv *priv;
505
506 priv = kunit_kzalloc(test, sizeof(*priv), GFP_KERNEL);
507 if (!priv)
508 return -ENOMEM;
509
510 test->priv = priv;
511
512 return 0;
513 }
514
515 static struct kunit_case string_stream_test_cases[] = {
516 KUNIT_CASE(string_stream_managed_init_test),
517 KUNIT_CASE(string_stream_unmanaged_init_test),
518 KUNIT_CASE(string_stream_managed_free_test),
519 KUNIT_CASE(string_stream_resource_free_test),
520 KUNIT_CASE(string_stream_line_add_test),
521 KUNIT_CASE(string_stream_variable_length_line_test),
522 KUNIT_CASE(string_stream_append_test),
523 KUNIT_CASE(string_stream_append_auto_newline_test),
524 KUNIT_CASE(string_stream_append_empty_string_test),
525 KUNIT_CASE(string_stream_no_auto_newline_test),
526 KUNIT_CASE(string_stream_auto_newline_test),
527 KUNIT_CASE(string_stream_performance_test),
528 {}
529 };
530
531 static struct kunit_suite string_stream_test_suite = {
532 .name = "string-stream-test",
533 .test_cases = string_stream_test_cases,
534 .init = string_stream_test_init,
535 };
536 kunit_test_suites(&string_stream_test_suite);
537
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