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
17struct 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(). */
25static void kfree_wrapper(void *p)
26{
27 kfree(objp: p);
28}
29
30/* Avoids a cast warning if string_stream_destroy() is passed direct to kunit_add_action(). */
31static void cleanup_raw_stream(void *p)
32{
33 struct string_stream *stream = p;
34
35 string_stream_destroy(stream);
36}
37
38static char *get_concatenated_string(struct kunit *test, struct string_stream *stream)
39{
40 char *str = string_stream_get_string(stream);
41
42 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, str);
43 kunit_add_action(test, action: kfree_wrapper, ctx: (void *)str);
44
45 return str;
46}
47
48/* Managed string_stream object is initialized correctly. */
49static void string_stream_managed_init_test(struct kunit *test)
50{
51 struct string_stream *stream;
52
53 /* Resource-managed initialization. */
54 stream = kunit_alloc_string_stream(test, GFP_KERNEL);
55 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, stream);
56
57 KUNIT_EXPECT_EQ(test, stream->length, 0);
58 KUNIT_EXPECT_TRUE(test, list_empty(&stream->fragments));
59 KUNIT_EXPECT_TRUE(test, (stream->gfp == GFP_KERNEL));
60 KUNIT_EXPECT_FALSE(test, stream->append_newlines);
61 KUNIT_EXPECT_TRUE(test, string_stream_is_empty(stream));
62}
63
64/* Unmanaged string_stream object is initialized correctly. */
65static void string_stream_unmanaged_init_test(struct kunit *test)
66{
67 struct string_stream *stream;
68
69 stream = alloc_string_stream(GFP_KERNEL);
70 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, stream);
71 kunit_add_action(test, action: cleanup_raw_stream, ctx: stream);
72
73 KUNIT_EXPECT_EQ(test, stream->length, 0);
74 KUNIT_EXPECT_TRUE(test, list_empty(&stream->fragments));
75 KUNIT_EXPECT_TRUE(test, (stream->gfp == GFP_KERNEL));
76 KUNIT_EXPECT_FALSE(test, stream->append_newlines);
77
78 KUNIT_EXPECT_TRUE(test, string_stream_is_empty(stream));
79}
80
81static void string_stream_destroy_stub(struct string_stream *stream)
82{
83 struct kunit *fake_test = kunit_get_current_test();
84 struct string_stream_test_priv *priv = fake_test->priv;
85
86 /* The kunit could own string_streams other than the one we are testing. */
87 if (stream == priv->expected_free_stream) {
88 if (priv->stream_was_freed)
89 priv->stream_free_again = true;
90 else
91 priv->stream_was_freed = true;
92 }
93
94 /*
95 * Calling string_stream_destroy() will only call this function again
96 * because the redirection stub is still active.
97 * Avoid calling deactivate_static_stub() or changing current->kunit_test
98 * during cleanup.
99 */
100 string_stream_clear(stream);
101 kfree(objp: stream);
102}
103
104/* kunit_free_string_stream() calls string_stream_desrtoy() */
105static void string_stream_managed_free_test(struct kunit *test)
106{
107 struct string_stream_test_priv *priv = test->priv;
108
109 priv->expected_free_stream = NULL;
110 priv->stream_was_freed = false;
111 priv->stream_free_again = false;
112
113 kunit_activate_static_stub(test,
114 string_stream_destroy,
115 string_stream_destroy_stub);
116
117 priv->expected_free_stream = kunit_alloc_string_stream(test, GFP_KERNEL);
118 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, priv->expected_free_stream);
119
120 /* This should call the stub function. */
121 kunit_free_string_stream(test, stream: priv->expected_free_stream);
122
123 KUNIT_EXPECT_TRUE(test, priv->stream_was_freed);
124 KUNIT_EXPECT_FALSE(test, priv->stream_free_again);
125}
126
127/* string_stream object is freed when test is cleaned up. */
128static void string_stream_resource_free_test(struct kunit *test)
129{
130 struct string_stream_test_priv *priv = test->priv;
131 struct kunit *fake_test;
132
133 fake_test = kunit_kzalloc(test, size: sizeof(*fake_test), GFP_KERNEL);
134 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, fake_test);
135
136 kunit_init_test(test: fake_test, name: "string_stream_fake_test", NULL);
137 fake_test->priv = priv;
138
139 /*
140 * Activate stub before creating string_stream so the
141 * string_stream will be cleaned up first.
142 */
143 priv->expected_free_stream = NULL;
144 priv->stream_was_freed = false;
145 priv->stream_free_again = false;
146
147 kunit_activate_static_stub(fake_test,
148 string_stream_destroy,
149 string_stream_destroy_stub);
150
151 priv->expected_free_stream = kunit_alloc_string_stream(test: fake_test, GFP_KERNEL);
152 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, priv->expected_free_stream);
153
154 /* Set current->kunit_test to fake_test so the static stub will be called. */
155 current->kunit_test = fake_test;
156
157 /* Cleanup test - the stub function should be called */
158 kunit_cleanup(test: fake_test);
159
160 /* Set current->kunit_test back to current test. */
161 current->kunit_test = test;
162
163 KUNIT_EXPECT_TRUE(test, priv->stream_was_freed);
164 KUNIT_EXPECT_FALSE(test, priv->stream_free_again);
165}
166
167/*
168 * Add a series of lines to a string_stream. Check that all lines
169 * appear in the correct order and no characters are dropped.
170 */
171static void string_stream_line_add_test(struct kunit *test)
172{
173 struct string_stream *stream;
174 char line[60];
175 char *concat_string, *pos, *string_end;
176 size_t len, total_len;
177 int num_lines, i;
178
179 stream = kunit_alloc_string_stream(test, GFP_KERNEL);
180 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, stream);
181
182 /* Add series of sequence numbered lines */
183 total_len = 0;
184 for (i = 0; i < 100; ++i) {
185 len = snprintf(buf: line, size: sizeof(line),
186 fmt: "The quick brown fox jumps over the lazy penguin %d\n", i);
187
188 /* Sanity-check that our test string isn't truncated */
189 KUNIT_ASSERT_LT(test, len, sizeof(line));
190
191 string_stream_add(stream, fmt: line);
192 total_len += len;
193 }
194 num_lines = i;
195
196 concat_string = get_concatenated_string(test, stream);
197 KUNIT_EXPECT_NOT_ERR_OR_NULL(test, concat_string);
198 KUNIT_EXPECT_EQ(test, strlen(concat_string), total_len);
199
200 /*
201 * Split the concatenated string at the newlines and check that
202 * all the original added strings are present.
203 */
204 pos = concat_string;
205 for (i = 0; i < num_lines; ++i) {
206 string_end = strchr(pos, '\n');
207 KUNIT_EXPECT_NOT_NULL(test, string_end);
208
209 /* Convert to NULL-terminated string */
210 *string_end = '\0';
211
212 snprintf(buf: line, size: sizeof(line),
213 fmt: "The quick brown fox jumps over the lazy penguin %d", i);
214 KUNIT_EXPECT_STREQ(test, pos, line);
215
216 pos = string_end + 1;
217 }
218
219 /* There shouldn't be any more data after this */
220 KUNIT_EXPECT_EQ(test, strlen(pos), 0);
221}
222
223/* Add a series of lines of variable length to a string_stream. */
224static void string_stream_variable_length_line_test(struct kunit *test)
225{
226 static const char line[] =
227 "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ"
228 " 0123456789!$%^&*()_-+={}[]:;@'~#<>,.?/|";
229 struct string_stream *stream;
230 struct rnd_state rnd;
231 char *concat_string, *pos, *string_end;
232 size_t offset, total_len;
233 int num_lines, i;
234
235 stream = kunit_alloc_string_stream(test, GFP_KERNEL);
236 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, stream);
237
238 /*
239 * Log many lines of varying lengths until we have created
240 * many fragments.
241 * The "randomness" must be repeatable.
242 */
243 prandom_seed_state(state: &rnd, seed: 3141592653589793238ULL);
244 total_len = 0;
245 for (i = 0; i < 100; ++i) {
246 offset = prandom_u32_state(state: &rnd) % (sizeof(line) - 1);
247 string_stream_add(stream, fmt: "%s\n", &line[offset]);
248 total_len += sizeof(line) - offset;
249 }
250 num_lines = i;
251
252 concat_string = get_concatenated_string(test, stream);
253 KUNIT_EXPECT_NOT_ERR_OR_NULL(test, concat_string);
254 KUNIT_EXPECT_EQ(test, strlen(concat_string), total_len);
255
256 /*
257 * Split the concatenated string at the newlines and check that
258 * all the original added strings are present.
259 */
260 prandom_seed_state(state: &rnd, seed: 3141592653589793238ULL);
261 pos = concat_string;
262 for (i = 0; i < num_lines; ++i) {
263 string_end = strchr(pos, '\n');
264 KUNIT_EXPECT_NOT_NULL(test, string_end);
265
266 /* Convert to NULL-terminated string */
267 *string_end = '\0';
268
269 offset = prandom_u32_state(state: &rnd) % (sizeof(line) - 1);
270 KUNIT_EXPECT_STREQ(test, pos, &line[offset]);
271
272 pos = string_end + 1;
273 }
274
275 /* There shouldn't be any more data after this */
276 KUNIT_EXPECT_EQ(test, strlen(pos), 0);
277}
278
279/* Appending the content of one string stream to another. */
280static void string_stream_append_test(struct kunit *test)
281{
282 static const char * const strings_1[] = {
283 "one", "two", "three", "four", "five", "six",
284 "seven", "eight", "nine", "ten",
285 };
286 static const char * const strings_2[] = {
287 "Apple", "Pear", "Orange", "Banana", "Grape", "Apricot",
288 };
289 struct string_stream *stream_1, *stream_2;
290 const char *stream1_content_before_append, *stream_2_content;
291 char *combined_content;
292 size_t combined_length;
293 int i;
294
295 stream_1 = kunit_alloc_string_stream(test, GFP_KERNEL);
296 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, stream_1);
297
298 stream_2 = kunit_alloc_string_stream(test, GFP_KERNEL);
299 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, stream_2);
300
301 /* Append content of empty stream to empty stream */
302 string_stream_append(stream: stream_1, other: stream_2);
303 KUNIT_EXPECT_EQ(test, strlen(get_concatenated_string(test, stream_1)), 0);
304
305 /* Add some data to stream_1 */
306 for (i = 0; i < ARRAY_SIZE(strings_1); ++i)
307 string_stream_add(stream: stream_1, fmt: "%s\n", strings_1[i]);
308
309 stream1_content_before_append = get_concatenated_string(test, stream: stream_1);
310
311 /* Append content of empty stream to non-empty stream */
312 string_stream_append(stream: stream_1, other: stream_2);
313 KUNIT_EXPECT_STREQ(test, get_concatenated_string(test, stream_1),
314 stream1_content_before_append);
315
316 /* Add some data to stream_2 */
317 for (i = 0; i < ARRAY_SIZE(strings_2); ++i)
318 string_stream_add(stream: stream_2, fmt: "%s\n", strings_2[i]);
319
320 /* Append content of non-empty stream to non-empty stream */
321 string_stream_append(stream: stream_1, other: stream_2);
322
323 /*
324 * End result should be the original content of stream_1 plus
325 * the content of stream_2.
326 */
327 stream_2_content = get_concatenated_string(test, stream: stream_2);
328 combined_length = strlen(stream1_content_before_append) + strlen(stream_2_content);
329 combined_length++; /* for terminating \0 */
330 combined_content = kunit_kmalloc(test, size: combined_length, GFP_KERNEL);
331 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, combined_content);
332 snprintf(buf: combined_content, size: combined_length, fmt: "%s%s",
333 stream1_content_before_append, stream_2_content);
334
335 KUNIT_EXPECT_STREQ(test, get_concatenated_string(test, stream_1), combined_content);
336
337 /* Append content of non-empty stream to empty stream */
338 kunit_free_string_stream(test, stream: stream_1);
339
340 stream_1 = kunit_alloc_string_stream(test, GFP_KERNEL);
341 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, stream_1);
342
343 string_stream_append(stream: stream_1, other: stream_2);
344 KUNIT_EXPECT_STREQ(test, get_concatenated_string(test, stream_1), stream_2_content);
345}
346
347/* Appending the content of one string stream to one with auto-newlining. */
348static void string_stream_append_auto_newline_test(struct kunit *test)
349{
350 struct string_stream *stream_1, *stream_2;
351
352 /* Stream 1 has newline appending enabled */
353 stream_1 = kunit_alloc_string_stream(test, GFP_KERNEL);
354 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, stream_1);
355 string_stream_set_append_newlines(stream: stream_1, append_newlines: true);
356 KUNIT_EXPECT_TRUE(test, stream_1->append_newlines);
357
358 /* Stream 2 does not append newlines */
359 stream_2 = kunit_alloc_string_stream(test, GFP_KERNEL);
360 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, stream_2);
361
362 /* Appending a stream with a newline should not add another newline */
363 string_stream_add(stream: stream_1, fmt: "Original string\n");
364 string_stream_add(stream: stream_2, fmt: "Appended content\n");
365 string_stream_add(stream: stream_2, fmt: "More stuff\n");
366 string_stream_append(stream: stream_1, other: stream_2);
367 KUNIT_EXPECT_STREQ(test, get_concatenated_string(test, stream_1),
368 "Original string\nAppended content\nMore stuff\n");
369
370 kunit_free_string_stream(test, stream: stream_2);
371 stream_2 = kunit_alloc_string_stream(test, GFP_KERNEL);
372 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, stream_2);
373
374 /*
375 * Appending a stream without newline should add a final newline.
376 * The appended string_stream is treated as a single string so newlines
377 * should not be inserted between fragments.
378 */
379 string_stream_add(stream: stream_2, fmt: "Another");
380 string_stream_add(stream: stream_2, fmt: "And again");
381 string_stream_append(stream: stream_1, other: stream_2);
382 KUNIT_EXPECT_STREQ(test, get_concatenated_string(test, stream_1),
383 "Original string\nAppended content\nMore stuff\nAnotherAnd again\n");
384}
385
386/* Adding an empty string should not create a fragment. */
387static void string_stream_append_empty_string_test(struct kunit *test)
388{
389 struct string_stream *stream;
390 int original_frag_count;
391
392 stream = kunit_alloc_string_stream(test, GFP_KERNEL);
393 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, stream);
394
395 /* Formatted empty string */
396 string_stream_add(stream, fmt: "%s", "");
397 KUNIT_EXPECT_TRUE(test, string_stream_is_empty(stream));
398 KUNIT_EXPECT_TRUE(test, list_empty(&stream->fragments));
399
400 /* Adding an empty string to a non-empty stream */
401 string_stream_add(stream, fmt: "Add this line");
402 original_frag_count = list_count_nodes(head: &stream->fragments);
403
404 string_stream_add(stream, fmt: "%s", "");
405 KUNIT_EXPECT_EQ(test, list_count_nodes(&stream->fragments), original_frag_count);
406 KUNIT_EXPECT_STREQ(test, get_concatenated_string(test, stream), "Add this line");
407}
408
409/* Adding strings without automatic newline appending */
410static void string_stream_no_auto_newline_test(struct kunit *test)
411{
412 struct string_stream *stream;
413
414 stream = kunit_alloc_string_stream(test, GFP_KERNEL);
415 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, stream);
416
417 /*
418 * Add some strings with and without newlines. All formatted newlines
419 * should be preserved. It should not add any extra newlines.
420 */
421 string_stream_add(stream, fmt: "One");
422 string_stream_add(stream, fmt: "Two\n");
423 string_stream_add(stream, fmt: "%s\n", "Three");
424 string_stream_add(stream, fmt: "%s", "Four\n");
425 string_stream_add(stream, fmt: "Five\n%s", "Six");
426 string_stream_add(stream, fmt: "Seven\n\n");
427 string_stream_add(stream, fmt: "Eight");
428 KUNIT_EXPECT_STREQ(test, get_concatenated_string(test, stream),
429 "OneTwo\nThree\nFour\nFive\nSixSeven\n\nEight");
430}
431
432/* Adding strings with automatic newline appending */
433static void string_stream_auto_newline_test(struct kunit *test)
434{
435 struct string_stream *stream;
436
437 stream = kunit_alloc_string_stream(test, GFP_KERNEL);
438 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, stream);
439
440 string_stream_set_append_newlines(stream, append_newlines: true);
441 KUNIT_EXPECT_TRUE(test, stream->append_newlines);
442
443 /*
444 * Add some strings with and without newlines. Newlines should
445 * be appended to lines that do not end with \n, but newlines
446 * resulting from the formatting should not be changed.
447 */
448 string_stream_add(stream, fmt: "One");
449 string_stream_add(stream, fmt: "Two\n");
450 string_stream_add(stream, fmt: "%s\n", "Three");
451 string_stream_add(stream, fmt: "%s", "Four\n");
452 string_stream_add(stream, fmt: "Five\n%s", "Six");
453 string_stream_add(stream, fmt: "Seven\n\n");
454 string_stream_add(stream, fmt: "Eight");
455 KUNIT_EXPECT_STREQ(test, get_concatenated_string(test, stream),
456 "One\nTwo\nThree\nFour\nFive\nSix\nSeven\n\nEight\n");
457}
458
459/*
460 * This doesn't actually "test" anything. It reports time taken
461 * and memory used for logging a large number of lines.
462 */
463static void string_stream_performance_test(struct kunit *test)
464{
465 struct string_stream_fragment *frag_container;
466 struct string_stream *stream;
467 char test_line[101];
468 ktime_t start_time, end_time;
469 size_t len, bytes_requested, actual_bytes_used, total_string_length;
470 int offset, i;
471
472 stream = kunit_alloc_string_stream(test, GFP_KERNEL);
473 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, stream);
474
475 memset(test_line, 'x', sizeof(test_line) - 1);
476 test_line[sizeof(test_line) - 1] = '\0';
477
478 start_time = ktime_get();
479 for (i = 0; i < 10000; i++) {
480 offset = i % (sizeof(test_line) - 1);
481 string_stream_add(stream, fmt: "%s: %d\n", &test_line[offset], i);
482 }
483 end_time = ktime_get();
484
485 /*
486 * Calculate memory used. This doesn't include invisible
487 * overhead due to kernel allocator fragment size rounding.
488 */
489 bytes_requested = sizeof(*stream);
490 actual_bytes_used = ksize(objp: stream);
491 total_string_length = 0;
492
493 list_for_each_entry(frag_container, &stream->fragments, node) {
494 bytes_requested += sizeof(*frag_container);
495 actual_bytes_used += ksize(objp: frag_container);
496
497 len = strlen(frag_container->fragment);
498 total_string_length += len;
499 bytes_requested += len + 1; /* +1 for '\0' */
500 actual_bytes_used += ksize(objp: frag_container->fragment);
501 }
502
503 kunit_info(test, "Time elapsed: %lld us\n",
504 ktime_us_delta(end_time, start_time));
505 kunit_info(test, "Total string length: %zu\n", total_string_length);
506 kunit_info(test, "Bytes requested: %zu\n", bytes_requested);
507 kunit_info(test, "Actual bytes allocated: %zu\n", actual_bytes_used);
508}
509
510static int string_stream_test_init(struct kunit *test)
511{
512 struct string_stream_test_priv *priv;
513
514 priv = kunit_kzalloc(test, size: sizeof(*priv), GFP_KERNEL);
515 if (!priv)
516 return -ENOMEM;
517
518 test->priv = priv;
519
520 return 0;
521}
522
523static struct kunit_case string_stream_test_cases[] = {
524 KUNIT_CASE(string_stream_managed_init_test),
525 KUNIT_CASE(string_stream_unmanaged_init_test),
526 KUNIT_CASE(string_stream_managed_free_test),
527 KUNIT_CASE(string_stream_resource_free_test),
528 KUNIT_CASE(string_stream_line_add_test),
529 KUNIT_CASE(string_stream_variable_length_line_test),
530 KUNIT_CASE(string_stream_append_test),
531 KUNIT_CASE(string_stream_append_auto_newline_test),
532 KUNIT_CASE(string_stream_append_empty_string_test),
533 KUNIT_CASE(string_stream_no_auto_newline_test),
534 KUNIT_CASE(string_stream_auto_newline_test),
535 KUNIT_CASE(string_stream_performance_test),
536 {}
537};
538
539static struct kunit_suite string_stream_test_suite = {
540 .name = "string-stream-test",
541 .test_cases = string_stream_test_cases,
542 .init = string_stream_test_init,
543};
544kunit_test_suites(&string_stream_test_suite);
545

source code of linux/lib/kunit/string-stream-test.c