lib/kunit/string-stream-test.c

   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 <[email protected]>
   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 static void kfree_wrapper(void *p)
  26 {
  27         kfree(p);
  28 }
  29
  30 /* Avoids a cast warning if string_stream_destroy() is passed direct to kunit_add_action(). */
  31 static void cleanup_raw_stream(void *p)
  32 {
  33         struct string_stream *stream = p;
  34
  35         string_stream_destroy(stream);
  36 }
  37
  38 static 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, kfree_wrapper, (void *)str);
  44
  45         return str;
  46 }
  47
  48 /* Managed string_stream object is initialized correctly. */
  49 static 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. */
  65 static 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, cleanup_raw_stream, 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
  81 static 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(stream);
 102 }
 103
 104 /* kunit_free_string_stream() calls string_stream_desrtoy() */
 105 static 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, 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. */
 128 static 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, sizeof(*fake_test), GFP_KERNEL);
 134         KUNIT_ASSERT_NOT_ERR_OR_NULL(test, fake_test);
 135
 136         kunit_init_test(fake_test, "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(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(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  */
 171 static 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(line, sizeof(line),
 186                         "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, 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(line, sizeof(line),
 213                          "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. */
 224 static 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(&rnd, 3141592653589793238ULL);
 244         total_len = 0;
 245         for (i = 0; i < 100; ++i) {
 246                 offset = prandom_u32_state(&rnd) % (sizeof(line) - 1);
 247                 string_stream_add(stream, "%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(&rnd, 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(&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. */
 280 static 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_1, 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_1, "%s\n", strings_1[i]);
 308
 309         stream1_content_before_append = get_concatenated_string(test, stream_1);
 310
 311         /* Append content of empty stream to non-empty stream */
 312         string_stream_append(stream_1, 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_2, "%s\n", strings_2[i]);
 319
 320         /* Append content of non-empty stream to non-empty stream */
 321         string_stream_append(stream_1, 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_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, combined_length, GFP_KERNEL);
 331         KUNIT_ASSERT_NOT_ERR_OR_NULL(test, combined_content);
 332         snprintf(combined_content, combined_length, "%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_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_1, 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. */
 348 static 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_1, 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_1, "Original string\n");
 364         string_stream_add(stream_2, "Appended content\n");
 365         string_stream_add(stream_2, "More stuff\n");
 366         string_stream_append(stream_1, 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_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_2, "Another");
 380         string_stream_add(stream_2, "And again");
 381         string_stream_append(stream_1, 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. */
 387 static 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, "%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, "Add this line");
 402         original_frag_count = list_count_nodes(&stream->fragments);
 403
 404         string_stream_add(stream, "%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 */
 410 static 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, "One");
 422         string_stream_add(stream, "Two\n");
 423         string_stream_add(stream, "%s\n", "Three");
 424         string_stream_add(stream, "%s", "Four\n");
 425         string_stream_add(stream, "Five\n%s", "Six");
 426         string_stream_add(stream, "Seven\n\n");
 427         string_stream_add(stream, "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 */
 433 static 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, 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, "One");
 449         string_stream_add(stream, "Two\n");
 450         string_stream_add(stream, "%s\n", "Three");
 451         string_stream_add(stream, "%s", "Four\n");
 452         string_stream_add(stream, "Five\n%s", "Six");
 453         string_stream_add(stream, "Seven\n\n");
 454         string_stream_add(stream, "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  */
 463 static 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, "%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(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(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(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
 510 static int string_stream_test_init(struct kunit *test)
 511 {
 512         struct string_stream_test_priv *priv;
 513
 514         priv = kunit_kzalloc(test, sizeof(*priv), GFP_KERNEL);
 515         if (!priv)
 516                 return -ENOMEM;
 517
 518         test->priv = priv;
 519
 520         return 0;
 521 }
 522
 523 static 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
 539 static 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 };
 544 kunit_test_suites(&string_stream_test_suite);