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/prandom.h> 13 #include <linux/slab.h> 14 #include <linux/timekeeping.h> 15 16 #include "string-stream.h" 17 18 struct string_stream_test_priv { 19 /* For testing resource-managed free. */ 20 struct string_stream *expected_free_stream; 21 bool stream_was_freed; 22 bool stream_free_again; 23 }; 24 25 /* Avoids a cast warning if kfree() is passed direct to kunit_add_action(). */ 26 KUNIT_DEFINE_ACTION_WRAPPER(kfree_wrapper, kfree, const void *); 27 28 /* Avoids a cast warning if string_stream_destroy() is passed direct to kunit_add_action(). */ 29 KUNIT_DEFINE_ACTION_WRAPPER(cleanup_raw_stream, string_stream_destroy, struct string_stream *); 30 31 static char *get_concatenated_string(struct kunit *test, struct string_stream *stream) 32 { 33 char *str = string_stream_get_string(stream); 34 35 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, str); 36 kunit_add_action(test, kfree_wrapper, (void *)str); 37 38 return str; 39 } 40 41 /* Managed string_stream object is initialized correctly. */ 42 static void string_stream_managed_init_test(struct kunit *test) 43 { 44 struct string_stream *stream; 45 46 /* Resource-managed initialization. */ 47 stream = kunit_alloc_string_stream(test, GFP_KERNEL); 48 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, stream); 49 50 KUNIT_EXPECT_EQ(test, stream->length, 0); 51 KUNIT_EXPECT_TRUE(test, list_empty(&stream->fragments)); 52 KUNIT_EXPECT_TRUE(test, (stream->gfp == GFP_KERNEL)); 53 KUNIT_EXPECT_FALSE(test, stream->append_newlines); 54 KUNIT_EXPECT_TRUE(test, string_stream_is_empty(stream)); 55 } 56 57 /* Unmanaged string_stream object is initialized correctly. */ 58 static void string_stream_unmanaged_init_test(struct kunit *test) 59 { 60 struct string_stream *stream; 61 62 stream = alloc_string_stream(GFP_KERNEL); 63 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, stream); 64 kunit_add_action(test, cleanup_raw_stream, stream); 65 66 KUNIT_EXPECT_EQ(test, stream->length, 0); 67 KUNIT_EXPECT_TRUE(test, list_empty(&stream->fragments)); 68 KUNIT_EXPECT_TRUE(test, (stream->gfp == GFP_KERNEL)); 69 KUNIT_EXPECT_FALSE(test, stream->append_newlines); 70 71 KUNIT_EXPECT_TRUE(test, string_stream_is_empty(stream)); 72 } 73 74 static void string_stream_destroy_stub(struct string_stream *stream) 75 { 76 struct kunit *fake_test = kunit_get_current_test(); 77 struct string_stream_test_priv *priv = fake_test->priv; 78 79 /* The kunit could own string_streams other than the one we are testing. */ 80 if (stream == priv->expected_free_stream) { 81 if (priv->stream_was_freed) 82 priv->stream_free_again = true; 83 else 84 priv->stream_was_freed = true; 85 } 86 87 /* 88 * Calling string_stream_destroy() will only call this function again 89 * because the redirection stub is still active. 90 * Avoid calling deactivate_static_stub() or changing current->kunit_test 91 * during cleanup. 92 */ 93 string_stream_clear(stream); 94 kfree(stream); 95 } 96 97 /* kunit_free_string_stream() calls string_stream_desrtoy() */ 98 static void string_stream_managed_free_test(struct kunit *test) 99 { 100 struct string_stream_test_priv *priv = test->priv; 101 102 priv->expected_free_stream = NULL; 103 priv->stream_was_freed = false; 104 priv->stream_free_again = false; 105 106 kunit_activate_static_stub(test, 107 string_stream_destroy, 108 string_stream_destroy_stub); 109 110 priv->expected_free_stream = kunit_alloc_string_stream(test, GFP_KERNEL); 111 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, priv->expected_free_stream); 112 113 /* This should call the stub function. */ 114 kunit_free_string_stream(test, priv->expected_free_stream); 115 116 KUNIT_EXPECT_TRUE(test, priv->stream_was_freed); 117 KUNIT_EXPECT_FALSE(test, priv->stream_free_again); 118 } 119 120 /* string_stream object is freed when test is cleaned up. */ 121 static void string_stream_resource_free_test(struct kunit *test) 122 { 123 struct string_stream_test_priv *priv = test->priv; 124 struct kunit *fake_test; 125 126 fake_test = kunit_kzalloc(test, sizeof(*fake_test), GFP_KERNEL); 127 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, fake_test); 128 129 kunit_init_test(fake_test, "string_stream_fake_test", NULL); 130 fake_test->priv = priv; 131 132 /* 133 * Activate stub before creating string_stream so the 134 * string_stream will be cleaned up first. 135 */ 136 priv->expected_free_stream = NULL; 137 priv->stream_was_freed = false; 138 priv->stream_free_again = false; 139 140 kunit_activate_static_stub(fake_test, 141 string_stream_destroy, 142 string_stream_destroy_stub); 143 144 priv->expected_free_stream = kunit_alloc_string_stream(fake_test, GFP_KERNEL); 145 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, priv->expected_free_stream); 146 147 /* Set current->kunit_test to fake_test so the static stub will be called. */ 148 current->kunit_test = fake_test; 149 150 /* Cleanup test - the stub function should be called */ 151 kunit_cleanup(fake_test); 152 153 /* Set current->kunit_test back to current test. */ 154 current->kunit_test = test; 155 156 KUNIT_EXPECT_TRUE(test, priv->stream_was_freed); 157 KUNIT_EXPECT_FALSE(test, priv->stream_free_again); 158 } 159 160 /* 161 * Add a series of lines to a string_stream. Check that all lines 162 * appear in the correct order and no characters are dropped. 163 */ 164 static void string_stream_line_add_test(struct kunit *test) 165 { 166 struct string_stream *stream; 167 char line[60]; 168 char *concat_string, *pos, *string_end; 169 size_t len, total_len; 170 int num_lines, i; 171 172 stream = kunit_alloc_string_stream(test, GFP_KERNEL); 173 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, stream); 174 175 /* Add series of sequence numbered lines */ 176 total_len = 0; 177 for (i = 0; i < 100; ++i) { 178 len = snprintf(line, sizeof(line), 179 "The quick brown fox jumps over the lazy penguin %d\n", i); 180 181 /* Sanity-check that our test string isn't truncated */ 182 KUNIT_ASSERT_LT(test, len, sizeof(line)); 183 184 string_stream_add(stream, line); 185 total_len += len; 186 } 187 num_lines = i; 188 189 concat_string = get_concatenated_string(test, stream); 190 KUNIT_EXPECT_NOT_ERR_OR_NULL(test, concat_string); 191 KUNIT_EXPECT_EQ(test, strlen(concat_string), total_len); 192 193 /* 194 * Split the concatenated string at the newlines and check that 195 * all the original added strings are present. 196 */ 197 pos = concat_string; 198 for (i = 0; i < num_lines; ++i) { 199 string_end = strchr(pos, '\n'); 200 KUNIT_EXPECT_NOT_NULL(test, string_end); 201 202 /* Convert to NULL-terminated string */ 203 *string_end = '\0'; 204 205 snprintf(line, sizeof(line), 206 "The quick brown fox jumps over the lazy penguin %d", i); 207 KUNIT_EXPECT_STREQ(test, pos, line); 208 209 pos = string_end + 1; 210 } 211 212 /* There shouldn't be any more data after this */ 213 KUNIT_EXPECT_EQ(test, strlen(pos), 0); 214 } 215 216 /* Add a series of lines of variable length to a string_stream. */ 217 static void string_stream_variable_length_line_test(struct kunit *test) 218 { 219 static const char line[] = 220 "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ" 221 " 0123456789!$%^&*()_-+={}[]:;@'~#<>,.?/|"; 222 struct string_stream *stream; 223 struct rnd_state rnd; 224 char *concat_string, *pos, *string_end; 225 size_t offset, total_len; 226 int num_lines, i; 227 228 stream = kunit_alloc_string_stream(test, GFP_KERNEL); 229 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, stream); 230 231 /* 232 * Log many lines of varying lengths until we have created 233 * many fragments. 234 * The "randomness" must be repeatable. 235 */ 236 prandom_seed_state(&rnd, 3141592653589793238ULL); 237 total_len = 0; 238 for (i = 0; i < 100; ++i) { 239 offset = prandom_u32_state(&rnd) % (sizeof(line) - 1); 240 string_stream_add(stream, "%s\n", &line[offset]); 241 total_len += sizeof(line) - offset; 242 } 243 num_lines = i; 244 245 concat_string = get_concatenated_string(test, stream); 246 KUNIT_EXPECT_NOT_ERR_OR_NULL(test, concat_string); 247 KUNIT_EXPECT_EQ(test, strlen(concat_string), total_len); 248 249 /* 250 * Split the concatenated string at the newlines and check that 251 * all the original added strings are present. 252 */ 253 prandom_seed_state(&rnd, 3141592653589793238ULL); 254 pos = concat_string; 255 for (i = 0; i < num_lines; ++i) { 256 string_end = strchr(pos, '\n'); 257 KUNIT_EXPECT_NOT_NULL(test, string_end); 258 259 /* Convert to NULL-terminated string */ 260 *string_end = '\0'; 261 262 offset = prandom_u32_state(&rnd) % (sizeof(line) - 1); 263 KUNIT_EXPECT_STREQ(test, pos, &line[offset]); 264 265 pos = string_end + 1; 266 } 267 268 /* There shouldn't be any more data after this */ 269 KUNIT_EXPECT_EQ(test, strlen(pos), 0); 270 } 271 272 /* Appending the content of one string stream to another. */ 273 static void string_stream_append_test(struct kunit *test) 274 { 275 static const char * const strings_1[] = { 276 "one", "two", "three", "four", "five", "six", 277 "seven", "eight", "nine", "ten", 278 }; 279 static const char * const strings_2[] = { 280 "Apple", "Pear", "Orange", "Banana", "Grape", "Apricot", 281 }; 282 struct string_stream *stream_1, *stream_2; 283 const char *stream1_content_before_append, *stream_2_content; 284 char *combined_content; 285 size_t combined_length; 286 int i; 287 288 stream_1 = kunit_alloc_string_stream(test, GFP_KERNEL); 289 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, stream_1); 290 291 stream_2 = kunit_alloc_string_stream(test, GFP_KERNEL); 292 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, stream_2); 293 294 /* Append content of empty stream to empty stream */ 295 string_stream_append(stream_1, stream_2); 296 KUNIT_EXPECT_EQ(test, strlen(get_concatenated_string(test, stream_1)), 0); 297 298 /* Add some data to stream_1 */ 299 for (i = 0; i < ARRAY_SIZE(strings_1); ++i) 300 string_stream_add(stream_1, "%s\n", strings_1[i]); 301 302 stream1_content_before_append = get_concatenated_string(test, stream_1); 303 304 /* Append content of empty stream to non-empty stream */ 305 string_stream_append(stream_1, stream_2); 306 KUNIT_EXPECT_STREQ(test, get_concatenated_string(test, stream_1), 307 stream1_content_before_append); 308 309 /* Add some data to stream_2 */ 310 for (i = 0; i < ARRAY_SIZE(strings_2); ++i) 311 string_stream_add(stream_2, "%s\n", strings_2[i]); 312 313 /* Append content of non-empty stream to non-empty stream */ 314 string_stream_append(stream_1, stream_2); 315 316 /* 317 * End result should be the original content of stream_1 plus 318 * the content of stream_2. 319 */ 320 stream_2_content = get_concatenated_string(test, stream_2); 321 combined_length = strlen(stream1_content_before_append) + strlen(stream_2_content); 322 combined_length++; /* for terminating \0 */ 323 combined_content = kunit_kmalloc(test, combined_length, GFP_KERNEL); 324 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, combined_content); 325 snprintf(combined_content, combined_length, "%s%s", 326 stream1_content_before_append, stream_2_content); 327 328 KUNIT_EXPECT_STREQ(test, get_concatenated_string(test, stream_1), combined_content); 329 330 /* Append content of non-empty stream to empty stream */ 331 kunit_free_string_stream(test, stream_1); 332 333 stream_1 = kunit_alloc_string_stream(test, GFP_KERNEL); 334 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, stream_1); 335 336 string_stream_append(stream_1, stream_2); 337 KUNIT_EXPECT_STREQ(test, get_concatenated_string(test, stream_1), stream_2_content); 338 } 339 340 /* Appending the content of one string stream to one with auto-newlining. */ 341 static void string_stream_append_auto_newline_test(struct kunit *test) 342 { 343 struct string_stream *stream_1, *stream_2; 344 345 /* Stream 1 has newline appending enabled */ 346 stream_1 = kunit_alloc_string_stream(test, GFP_KERNEL); 347 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, stream_1); 348 string_stream_set_append_newlines(stream_1, true); 349 KUNIT_EXPECT_TRUE(test, stream_1->append_newlines); 350 351 /* Stream 2 does not append newlines */ 352 stream_2 = kunit_alloc_string_stream(test, GFP_KERNEL); 353 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, stream_2); 354 355 /* Appending a stream with a newline should not add another newline */ 356 string_stream_add(stream_1, "Original string\n"); 357 string_stream_add(stream_2, "Appended content\n"); 358 string_stream_add(stream_2, "More stuff\n"); 359 string_stream_append(stream_1, stream_2); 360 KUNIT_EXPECT_STREQ(test, get_concatenated_string(test, stream_1), 361 "Original string\nAppended content\nMore stuff\n"); 362 363 kunit_free_string_stream(test, stream_2); 364 stream_2 = kunit_alloc_string_stream(test, GFP_KERNEL); 365 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, stream_2); 366 367 /* 368 * Appending a stream without newline should add a final newline. 369 * The appended string_stream is treated as a single string so newlines 370 * should not be inserted between fragments. 371 */ 372 string_stream_add(stream_2, "Another"); 373 string_stream_add(stream_2, "And again"); 374 string_stream_append(stream_1, stream_2); 375 KUNIT_EXPECT_STREQ(test, get_concatenated_string(test, stream_1), 376 "Original string\nAppended content\nMore stuff\nAnotherAnd again\n"); 377 } 378 379 /* Adding an empty string should not create a fragment. */ 380 static void string_stream_append_empty_string_test(struct kunit *test) 381 { 382 struct string_stream *stream; 383 int original_frag_count; 384 385 stream = kunit_alloc_string_stream(test, GFP_KERNEL); 386 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, stream); 387 388 /* Formatted empty string */ 389 string_stream_add(stream, "%s", ""); 390 KUNIT_EXPECT_TRUE(test, string_stream_is_empty(stream)); 391 KUNIT_EXPECT_TRUE(test, list_empty(&stream->fragments)); 392 393 /* Adding an empty string to a non-empty stream */ 394 string_stream_add(stream, "Add this line"); 395 original_frag_count = list_count_nodes(&stream->fragments); 396 397 string_stream_add(stream, "%s", ""); 398 KUNIT_EXPECT_EQ(test, list_count_nodes(&stream->fragments), original_frag_count); 399 KUNIT_EXPECT_STREQ(test, get_concatenated_string(test, stream), "Add this line"); 400 } 401 402 /* Adding strings without automatic newline appending */ 403 static void string_stream_no_auto_newline_test(struct kunit *test) 404 { 405 struct string_stream *stream; 406 407 stream = kunit_alloc_string_stream(test, GFP_KERNEL); 408 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, stream); 409 410 /* 411 * Add some strings with and without newlines. All formatted newlines 412 * should be preserved. It should not add any extra newlines. 413 */ 414 string_stream_add(stream, "One"); 415 string_stream_add(stream, "Two\n"); 416 string_stream_add(stream, "%s\n", "Three"); 417 string_stream_add(stream, "%s", "Four\n"); 418 string_stream_add(stream, "Five\n%s", "Six"); 419 string_stream_add(stream, "Seven\n\n"); 420 string_stream_add(stream, "Eight"); 421 KUNIT_EXPECT_STREQ(test, get_concatenated_string(test, stream), 422 "OneTwo\nThree\nFour\nFive\nSixSeven\n\nEight"); 423 } 424 425 /* Adding strings with automatic newline appending */ 426 static void string_stream_auto_newline_test(struct kunit *test) 427 { 428 struct string_stream *stream; 429 430 stream = kunit_alloc_string_stream(test, GFP_KERNEL); 431 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, stream); 432 433 string_stream_set_append_newlines(stream, true); 434 KUNIT_EXPECT_TRUE(test, stream->append_newlines); 435 436 /* 437 * Add some strings with and without newlines. Newlines should 438 * be appended to lines that do not end with \n, but newlines 439 * resulting from the formatting should not be changed. 440 */ 441 string_stream_add(stream, "One"); 442 string_stream_add(stream, "Two\n"); 443 string_stream_add(stream, "%s\n", "Three"); 444 string_stream_add(stream, "%s", "Four\n"); 445 string_stream_add(stream, "Five\n%s", "Six"); 446 string_stream_add(stream, "Seven\n\n"); 447 string_stream_add(stream, "Eight"); 448 KUNIT_EXPECT_STREQ(test, get_concatenated_string(test, stream), 449 "One\nTwo\nThree\nFour\nFive\nSix\nSeven\n\nEight\n"); 450 } 451 452 /* 453 * This doesn't actually "test" anything. It reports time taken 454 * and memory used for logging a large number of lines. 455 */ 456 static void string_stream_performance_test(struct kunit *test) 457 { 458 struct string_stream_fragment *frag_container; 459 struct string_stream *stream; 460 char test_line[101]; 461 ktime_t start_time, end_time; 462 size_t len, bytes_requested, actual_bytes_used, total_string_length; 463 int offset, i; 464 465 stream = kunit_alloc_string_stream(test, GFP_KERNEL); 466 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, stream); 467 468 memset(test_line, 'x', sizeof(test_line) - 1); 469 test_line[sizeof(test_line) - 1] = '\0'; 470 471 start_time = ktime_get(); 472 for (i = 0; i < 10000; i++) { 473 offset = i % (sizeof(test_line) - 1); 474 string_stream_add(stream, "%s: %d\n", &test_line[offset], i); 475 } 476 end_time = ktime_get(); 477 478 /* 479 * Calculate memory used. This doesn't include invisible 480 * overhead due to kernel allocator fragment size rounding. 481 */ 482 bytes_requested = sizeof(*stream); 483 actual_bytes_used = ksize(stream); 484 total_string_length = 0; 485 486 list_for_each_entry(frag_container, &stream->fragments, node) { 487 bytes_requested += sizeof(*frag_container); 488 actual_bytes_used += ksize(frag_container); 489 490 len = strlen(frag_container->fragment); 491 total_string_length += len; 492 bytes_requested += len + 1; /* +1 for '\0' */ 493 actual_bytes_used += ksize(frag_container->fragment); 494 } 495 496 kunit_info(test, "Time elapsed: %lld us\n", 497 ktime_us_delta(end_time, start_time)); 498 kunit_info(test, "Total string length: %zu\n", total_string_length); 499 kunit_info(test, "Bytes requested: %zu\n", bytes_requested); 500 kunit_info(test, "Actual bytes allocated: %zu\n", actual_bytes_used); 501 } 502 503 static int string_stream_test_init(struct kunit *test) 504 { 505 struct string_stream_test_priv *priv; 506 507 priv = kunit_kzalloc(test, sizeof(*priv), GFP_KERNEL); 508 if (!priv) 509 return -ENOMEM; 510 511 test->priv = priv; 512 513 return 0; 514 } 515 516 static struct kunit_case string_stream_test_cases[] = { 517 KUNIT_CASE(string_stream_managed_init_test), 518 KUNIT_CASE(string_stream_unmanaged_init_test), 519 KUNIT_CASE(string_stream_managed_free_test), 520 KUNIT_CASE(string_stream_resource_free_test), 521 KUNIT_CASE(string_stream_line_add_test), 522 KUNIT_CASE(string_stream_variable_length_line_test), 523 KUNIT_CASE(string_stream_append_test), 524 KUNIT_CASE(string_stream_append_auto_newline_test), 525 KUNIT_CASE(string_stream_append_empty_string_test), 526 KUNIT_CASE(string_stream_no_auto_newline_test), 527 KUNIT_CASE(string_stream_auto_newline_test), 528 KUNIT_CASE(string_stream_performance_test), 529 {} 530 }; 531 532 static struct kunit_suite string_stream_test_suite = { 533 .name = "string-stream-test", 534 .test_cases = string_stream_test_cases, 535 .init = string_stream_test_init, 536 }; 537 kunit_test_suites(&string_stream_test_suite); 538