1 // SPDX-License-Identifier: GPL-2.0-or-later OR copyleft-next-0.3.1 2 /* 3 * kmod stress test driver 4 * 5 * Copyright (C) 2017 Luis R. Rodriguez <mcgrof@kernel.org> 6 */ 7 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 8 9 /* 10 * This driver provides an interface to trigger and test the kernel's 11 * module loader through a series of configurations and a few triggers. 12 * To test this driver use the following script as root: 13 * 14 * tools/testing/selftests/kmod/kmod.sh --help 15 */ 16 17 #include <linux/kernel.h> 18 #include <linux/module.h> 19 #include <linux/kmod.h> 20 #include <linux/printk.h> 21 #include <linux/kthread.h> 22 #include <linux/sched.h> 23 #include <linux/fs.h> 24 #include <linux/miscdevice.h> 25 #include <linux/vmalloc.h> 26 #include <linux/slab.h> 27 #include <linux/device.h> 28 29 #define TEST_START_NUM_THREADS 50 30 #define TEST_START_DRIVER "test_module" 31 #define TEST_START_TEST_FS "xfs" 32 #define TEST_START_TEST_CASE TEST_KMOD_DRIVER 33 34 35 static bool force_init_test = false; 36 module_param(force_init_test, bool_enable_only, 0644); 37 MODULE_PARM_DESC(force_init_test, 38 "Force kicking a test immediately after driver loads"); 39 40 /* 41 * For device allocation / registration 42 */ 43 static DEFINE_MUTEX(reg_dev_mutex); 44 static LIST_HEAD(reg_test_devs); 45 46 /* 47 * num_test_devs actually represents the *next* ID of the next 48 * device we will allow to create. 49 */ 50 static int num_test_devs; 51 52 /** 53 * enum kmod_test_case - linker table test case 54 * @TEST_KMOD_DRIVER: stress tests request_module() 55 * @TEST_KMOD_FS_TYPE: stress tests get_fs_type() 56 * 57 * If you add a test case, please be sure to review if you need to set 58 * @need_mod_put for your tests case. 59 */ 60 enum kmod_test_case { 61 __TEST_KMOD_INVALID = 0, 62 63 TEST_KMOD_DRIVER, 64 TEST_KMOD_FS_TYPE, 65 66 __TEST_KMOD_MAX, 67 }; 68 69 struct test_config { 70 char *test_driver; 71 char *test_fs; 72 unsigned int num_threads; 73 enum kmod_test_case test_case; 74 int test_result; 75 }; 76 77 struct kmod_test_device; 78 79 /** 80 * struct kmod_test_device_info - thread info 81 * 82 * @ret_sync: return value if request_module() is used, sync request for 83 * @TEST_KMOD_DRIVER 84 * @fs_sync: return value of get_fs_type() for @TEST_KMOD_FS_TYPE 85 * @thread_idx: thread ID 86 * @test_dev: test device test is being performed under 87 * @need_mod_put: Some tests (get_fs_type() is one) requires putting the module 88 * (module_put(fs_sync->owner)) when done, otherwise you will not be able 89 * to unload the respective modules and re-test. We use this to keep 90 * accounting of when we need this and to help out in case we need to 91 * error out and deal with module_put() on error. 92 */ 93 struct kmod_test_device_info { 94 int ret_sync; 95 struct file_system_type *fs_sync; 96 struct task_struct *task_sync; 97 unsigned int thread_idx; 98 struct kmod_test_device *test_dev; 99 bool need_mod_put; 100 }; 101 102 /** 103 * struct kmod_test_device - test device to help test kmod 104 * 105 * @dev_idx: unique ID for test device 106 * @config: configuration for the test 107 * @misc_dev: we use a misc device under the hood 108 * @dev: pointer to misc_dev's own struct device 109 * @config_mutex: protects configuration of test 110 * @trigger_mutex: the test trigger can only be fired once at a time 111 * @thread_lock: protects @done count, and the @info per each thread 112 * @done: number of threads which have completed or failed 113 * @test_is_oom: when we run out of memory, use this to halt moving forward 114 * @kthreads_done: completion used to signal when all work is done 115 * @list: needed to be part of the reg_test_devs 116 * @info: array of info for each thread 117 */ 118 struct kmod_test_device { 119 int dev_idx; 120 struct test_config config; 121 struct miscdevice misc_dev; 122 struct device *dev; 123 struct mutex config_mutex; 124 struct mutex trigger_mutex; 125 struct mutex thread_mutex; 126 127 unsigned int done; 128 129 bool test_is_oom; 130 struct completion kthreads_done; 131 struct list_head list; 132 133 struct kmod_test_device_info *info; 134 }; 135 136 static const char *test_case_str(enum kmod_test_case test_case) 137 { 138 switch (test_case) { 139 case TEST_KMOD_DRIVER: 140 return "TEST_KMOD_DRIVER"; 141 case TEST_KMOD_FS_TYPE: 142 return "TEST_KMOD_FS_TYPE"; 143 default: 144 return "invalid"; 145 } 146 } 147 148 static struct miscdevice *dev_to_misc_dev(struct device *dev) 149 { 150 return dev_get_drvdata(dev); 151 } 152 153 static struct kmod_test_device *misc_dev_to_test_dev(struct miscdevice *misc_dev) 154 { 155 return container_of(misc_dev, struct kmod_test_device, misc_dev); 156 } 157 158 static struct kmod_test_device *dev_to_test_dev(struct device *dev) 159 { 160 struct miscdevice *misc_dev; 161 162 misc_dev = dev_to_misc_dev(dev); 163 164 return misc_dev_to_test_dev(misc_dev); 165 } 166 167 /* Must run with thread_mutex held */ 168 static void kmod_test_done_check(struct kmod_test_device *test_dev, 169 unsigned int idx) 170 { 171 struct test_config *config = &test_dev->config; 172 173 test_dev->done++; 174 dev_dbg(test_dev->dev, "Done thread count: %u\n", test_dev->done); 175 176 if (test_dev->done == config->num_threads) { 177 dev_info(test_dev->dev, "Done: %u threads have all run now\n", 178 test_dev->done); 179 dev_info(test_dev->dev, "Last thread to run: %u\n", idx); 180 complete(&test_dev->kthreads_done); 181 } 182 } 183 184 static void test_kmod_put_module(struct kmod_test_device_info *info) 185 { 186 struct kmod_test_device *test_dev = info->test_dev; 187 struct test_config *config = &test_dev->config; 188 189 if (!info->need_mod_put) 190 return; 191 192 switch (config->test_case) { 193 case TEST_KMOD_DRIVER: 194 break; 195 case TEST_KMOD_FS_TYPE: 196 if (info->fs_sync && info->fs_sync->owner) 197 module_put(info->fs_sync->owner); 198 break; 199 default: 200 BUG(); 201 } 202 203 info->need_mod_put = true; 204 } 205 206 static int run_request(void *data) 207 { 208 struct kmod_test_device_info *info = data; 209 struct kmod_test_device *test_dev = info->test_dev; 210 struct test_config *config = &test_dev->config; 211 212 switch (config->test_case) { 213 case TEST_KMOD_DRIVER: 214 info->ret_sync = request_module("%s", config->test_driver); 215 break; 216 case TEST_KMOD_FS_TYPE: 217 info->fs_sync = get_fs_type(config->test_fs); 218 info->need_mod_put = true; 219 break; 220 default: 221 /* __trigger_config_run() already checked for test sanity */ 222 BUG(); 223 return -EINVAL; 224 } 225 226 dev_dbg(test_dev->dev, "Ran thread %u\n", info->thread_idx); 227 228 test_kmod_put_module(info); 229 230 mutex_lock(&test_dev->thread_mutex); 231 info->task_sync = NULL; 232 kmod_test_done_check(test_dev, info->thread_idx); 233 mutex_unlock(&test_dev->thread_mutex); 234 235 return 0; 236 } 237 238 static int tally_work_test(struct kmod_test_device_info *info) 239 { 240 struct kmod_test_device *test_dev = info->test_dev; 241 struct test_config *config = &test_dev->config; 242 int err_ret = 0; 243 244 switch (config->test_case) { 245 case TEST_KMOD_DRIVER: 246 /* 247 * Only capture errors, if one is found that's 248 * enough, for now. 249 */ 250 if (info->ret_sync != 0) 251 err_ret = info->ret_sync; 252 dev_info(test_dev->dev, 253 "Sync thread %d return status: %d\n", 254 info->thread_idx, info->ret_sync); 255 break; 256 case TEST_KMOD_FS_TYPE: 257 /* For now we make this simple */ 258 if (!info->fs_sync) 259 err_ret = -EINVAL; 260 dev_info(test_dev->dev, "Sync thread %u fs: %s\n", 261 info->thread_idx, info->fs_sync ? config->test_fs : 262 "NULL"); 263 break; 264 default: 265 BUG(); 266 } 267 268 return err_ret; 269 } 270 271 /* 272 * XXX: add result option to display if all errors did not match. 273 * For now we just keep any error code if one was found. 274 * 275 * If this ran it means *all* tasks were created fine and we 276 * are now just collecting results. 277 * 278 * Only propagate errors, do not override with a subsequent success case. 279 */ 280 static void tally_up_work(struct kmod_test_device *test_dev) 281 { 282 struct test_config *config = &test_dev->config; 283 struct kmod_test_device_info *info; 284 unsigned int idx; 285 int err_ret = 0; 286 int ret = 0; 287 288 mutex_lock(&test_dev->thread_mutex); 289 290 dev_info(test_dev->dev, "Results:\n"); 291 292 for (idx=0; idx < config->num_threads; idx++) { 293 info = &test_dev->info[idx]; 294 ret = tally_work_test(info); 295 if (ret) 296 err_ret = ret; 297 } 298 299 /* 300 * Note: request_module() returns 256 for a module not found even 301 * though modprobe itself returns 1. 302 */ 303 config->test_result = err_ret; 304 305 mutex_unlock(&test_dev->thread_mutex); 306 } 307 308 static int try_one_request(struct kmod_test_device *test_dev, unsigned int idx) 309 { 310 struct kmod_test_device_info *info = &test_dev->info[idx]; 311 int fail_ret = -ENOMEM; 312 313 mutex_lock(&test_dev->thread_mutex); 314 315 info->thread_idx = idx; 316 info->test_dev = test_dev; 317 info->task_sync = kthread_run(run_request, info, "%s-%u", 318 KBUILD_MODNAME, idx); 319 320 if (!info->task_sync || IS_ERR(info->task_sync)) { 321 test_dev->test_is_oom = true; 322 dev_err(test_dev->dev, "Setting up thread %u failed\n", idx); 323 info->task_sync = NULL; 324 goto err_out; 325 } else 326 dev_dbg(test_dev->dev, "Kicked off thread %u\n", idx); 327 328 mutex_unlock(&test_dev->thread_mutex); 329 330 return 0; 331 332 err_out: 333 info->ret_sync = fail_ret; 334 mutex_unlock(&test_dev->thread_mutex); 335 336 return fail_ret; 337 } 338 339 static void test_dev_kmod_stop_tests(struct kmod_test_device *test_dev) 340 { 341 struct test_config *config = &test_dev->config; 342 struct kmod_test_device_info *info; 343 unsigned int i; 344 345 dev_info(test_dev->dev, "Ending request_module() tests\n"); 346 347 mutex_lock(&test_dev->thread_mutex); 348 349 for (i=0; i < config->num_threads; i++) { 350 info = &test_dev->info[i]; 351 if (info->task_sync && !IS_ERR(info->task_sync)) { 352 dev_info(test_dev->dev, 353 "Stopping still-running thread %i\n", i); 354 kthread_stop(info->task_sync); 355 } 356 357 /* 358 * info->task_sync is well protected, it can only be 359 * NULL or a pointer to a struct. If its NULL we either 360 * never ran, or we did and we completed the work. Completed 361 * tasks *always* put the module for us. This is a sanity 362 * check -- just in case. 363 */ 364 if (info->task_sync && info->need_mod_put) 365 test_kmod_put_module(info); 366 } 367 368 mutex_unlock(&test_dev->thread_mutex); 369 } 370 371 /* 372 * Only wait *iff* we did not run into any errors during all of our thread 373 * set up. If run into any issues we stop threads and just bail out with 374 * an error to the trigger. This also means we don't need any tally work 375 * for any threads which fail. 376 */ 377 static int try_requests(struct kmod_test_device *test_dev) 378 { 379 struct test_config *config = &test_dev->config; 380 unsigned int idx; 381 int ret; 382 bool any_error = false; 383 384 for (idx=0; idx < config->num_threads; idx++) { 385 if (test_dev->test_is_oom) { 386 any_error = true; 387 break; 388 } 389 390 ret = try_one_request(test_dev, idx); 391 if (ret) { 392 any_error = true; 393 break; 394 } 395 } 396 397 if (!any_error) { 398 test_dev->test_is_oom = false; 399 dev_info(test_dev->dev, 400 "No errors were found while initializing threads\n"); 401 wait_for_completion(&test_dev->kthreads_done); 402 tally_up_work(test_dev); 403 } else { 404 test_dev->test_is_oom = true; 405 dev_info(test_dev->dev, 406 "At least one thread failed to start, stop all work\n"); 407 test_dev_kmod_stop_tests(test_dev); 408 return -ENOMEM; 409 } 410 411 return 0; 412 } 413 414 static int run_test_driver(struct kmod_test_device *test_dev) 415 { 416 struct test_config *config = &test_dev->config; 417 418 dev_info(test_dev->dev, "Test case: %s (%u)\n", 419 test_case_str(config->test_case), 420 config->test_case); 421 dev_info(test_dev->dev, "Test driver to load: %s\n", 422 config->test_driver); 423 dev_info(test_dev->dev, "Number of threads to run: %u\n", 424 config->num_threads); 425 dev_info(test_dev->dev, "Thread IDs will range from 0 - %u\n", 426 config->num_threads - 1); 427 428 return try_requests(test_dev); 429 } 430 431 static int run_test_fs_type(struct kmod_test_device *test_dev) 432 { 433 struct test_config *config = &test_dev->config; 434 435 dev_info(test_dev->dev, "Test case: %s (%u)\n", 436 test_case_str(config->test_case), 437 config->test_case); 438 dev_info(test_dev->dev, "Test filesystem to load: %s\n", 439 config->test_fs); 440 dev_info(test_dev->dev, "Number of threads to run: %u\n", 441 config->num_threads); 442 dev_info(test_dev->dev, "Thread IDs will range from 0 - %u\n", 443 config->num_threads - 1); 444 445 return try_requests(test_dev); 446 } 447 448 static ssize_t config_show(struct device *dev, 449 struct device_attribute *attr, 450 char *buf) 451 { 452 struct kmod_test_device *test_dev = dev_to_test_dev(dev); 453 struct test_config *config = &test_dev->config; 454 int len = 0; 455 456 mutex_lock(&test_dev->config_mutex); 457 458 len += snprintf(buf, PAGE_SIZE, 459 "Custom trigger configuration for: %s\n", 460 dev_name(dev)); 461 462 len += snprintf(buf+len, PAGE_SIZE - len, 463 "Number of threads:\t%u\n", 464 config->num_threads); 465 466 len += snprintf(buf+len, PAGE_SIZE - len, 467 "Test_case:\t%s (%u)\n", 468 test_case_str(config->test_case), 469 config->test_case); 470 471 if (config->test_driver) 472 len += snprintf(buf+len, PAGE_SIZE - len, 473 "driver:\t%s\n", 474 config->test_driver); 475 else 476 len += snprintf(buf+len, PAGE_SIZE - len, 477 "driver:\tEMPTY\n"); 478 479 if (config->test_fs) 480 len += snprintf(buf+len, PAGE_SIZE - len, 481 "fs:\t%s\n", 482 config->test_fs); 483 else 484 len += snprintf(buf+len, PAGE_SIZE - len, 485 "fs:\tEMPTY\n"); 486 487 mutex_unlock(&test_dev->config_mutex); 488 489 return len; 490 } 491 static DEVICE_ATTR_RO(config); 492 493 /* 494 * This ensures we don't allow kicking threads through if our configuration 495 * is faulty. 496 */ 497 static int __trigger_config_run(struct kmod_test_device *test_dev) 498 { 499 struct test_config *config = &test_dev->config; 500 501 test_dev->done = 0; 502 503 switch (config->test_case) { 504 case TEST_KMOD_DRIVER: 505 return run_test_driver(test_dev); 506 case TEST_KMOD_FS_TYPE: 507 return run_test_fs_type(test_dev); 508 default: 509 dev_warn(test_dev->dev, 510 "Invalid test case requested: %u\n", 511 config->test_case); 512 return -EINVAL; 513 } 514 } 515 516 static int trigger_config_run(struct kmod_test_device *test_dev) 517 { 518 struct test_config *config = &test_dev->config; 519 int ret; 520 521 mutex_lock(&test_dev->trigger_mutex); 522 mutex_lock(&test_dev->config_mutex); 523 524 ret = __trigger_config_run(test_dev); 525 if (ret < 0) 526 goto out; 527 dev_info(test_dev->dev, "General test result: %d\n", 528 config->test_result); 529 530 /* 531 * We must return 0 after a trigger even unless something went 532 * wrong with the setup of the test. If the test setup went fine 533 * then userspace must just check the result of config->test_result. 534 * One issue with relying on the return from a call in the kernel 535 * is if the kernel returns a positive value using this trigger 536 * will not return the value to userspace, it would be lost. 537 * 538 * By not relying on capturing the return value of tests we are using 539 * through the trigger it also us to run tests with set -e and only 540 * fail when something went wrong with the driver upon trigger 541 * requests. 542 */ 543 ret = 0; 544 545 out: 546 mutex_unlock(&test_dev->config_mutex); 547 mutex_unlock(&test_dev->trigger_mutex); 548 549 return ret; 550 } 551 552 static ssize_t 553 trigger_config_store(struct device *dev, 554 struct device_attribute *attr, 555 const char *buf, size_t count) 556 { 557 struct kmod_test_device *test_dev = dev_to_test_dev(dev); 558 int ret; 559 560 if (test_dev->test_is_oom) 561 return -ENOMEM; 562 563 /* For all intents and purposes we don't care what userspace 564 * sent this trigger, we care only that we were triggered. 565 * We treat the return value only for caputuring issues with 566 * the test setup. At this point all the test variables should 567 * have been allocated so typically this should never fail. 568 */ 569 ret = trigger_config_run(test_dev); 570 if (unlikely(ret < 0)) 571 goto out; 572 573 /* 574 * Note: any return > 0 will be treated as success 575 * and the error value will not be available to userspace. 576 * Do not rely on trying to send to userspace a test value 577 * return value as positive return errors will be lost. 578 */ 579 if (WARN_ON(ret > 0)) 580 return -EINVAL; 581 582 ret = count; 583 out: 584 return ret; 585 } 586 static DEVICE_ATTR_WO(trigger_config); 587 588 /* 589 * XXX: move to kstrncpy() once merged. 590 * 591 * Users should use kfree_const() when freeing these. 592 */ 593 static int __kstrncpy(char **dst, const char *name, size_t count, gfp_t gfp) 594 { 595 *dst = kstrndup(name, count, gfp); 596 if (!*dst) 597 return -ENOSPC; 598 return count; 599 } 600 601 static int config_copy_test_driver_name(struct test_config *config, 602 const char *name, 603 size_t count) 604 { 605 return __kstrncpy(&config->test_driver, name, count, GFP_KERNEL); 606 } 607 608 609 static int config_copy_test_fs(struct test_config *config, const char *name, 610 size_t count) 611 { 612 return __kstrncpy(&config->test_fs, name, count, GFP_KERNEL); 613 } 614 615 static void __kmod_config_free(struct test_config *config) 616 { 617 if (!config) 618 return; 619 620 kfree_const(config->test_driver); 621 config->test_driver = NULL; 622 623 kfree_const(config->test_fs); 624 config->test_fs = NULL; 625 } 626 627 static void kmod_config_free(struct kmod_test_device *test_dev) 628 { 629 struct test_config *config; 630 631 if (!test_dev) 632 return; 633 634 config = &test_dev->config; 635 636 mutex_lock(&test_dev->config_mutex); 637 __kmod_config_free(config); 638 mutex_unlock(&test_dev->config_mutex); 639 } 640 641 static ssize_t config_test_driver_store(struct device *dev, 642 struct device_attribute *attr, 643 const char *buf, size_t count) 644 { 645 struct kmod_test_device *test_dev = dev_to_test_dev(dev); 646 struct test_config *config = &test_dev->config; 647 int copied; 648 649 mutex_lock(&test_dev->config_mutex); 650 651 kfree_const(config->test_driver); 652 config->test_driver = NULL; 653 654 copied = config_copy_test_driver_name(config, buf, count); 655 mutex_unlock(&test_dev->config_mutex); 656 657 return copied; 658 } 659 660 /* 661 * As per sysfs_kf_seq_show() the buf is max PAGE_SIZE. 662 */ 663 static ssize_t config_test_show_str(struct mutex *config_mutex, 664 char *dst, 665 char *src) 666 { 667 int len; 668 669 mutex_lock(config_mutex); 670 len = snprintf(dst, PAGE_SIZE, "%s\n", src); 671 mutex_unlock(config_mutex); 672 673 return len; 674 } 675 676 static ssize_t config_test_driver_show(struct device *dev, 677 struct device_attribute *attr, 678 char *buf) 679 { 680 struct kmod_test_device *test_dev = dev_to_test_dev(dev); 681 struct test_config *config = &test_dev->config; 682 683 return config_test_show_str(&test_dev->config_mutex, buf, 684 config->test_driver); 685 } 686 static DEVICE_ATTR_RW(config_test_driver); 687 688 static ssize_t config_test_fs_store(struct device *dev, 689 struct device_attribute *attr, 690 const char *buf, size_t count) 691 { 692 struct kmod_test_device *test_dev = dev_to_test_dev(dev); 693 struct test_config *config = &test_dev->config; 694 int copied; 695 696 mutex_lock(&test_dev->config_mutex); 697 698 kfree_const(config->test_fs); 699 config->test_fs = NULL; 700 701 copied = config_copy_test_fs(config, buf, count); 702 mutex_unlock(&test_dev->config_mutex); 703 704 return copied; 705 } 706 707 static ssize_t config_test_fs_show(struct device *dev, 708 struct device_attribute *attr, 709 char *buf) 710 { 711 struct kmod_test_device *test_dev = dev_to_test_dev(dev); 712 struct test_config *config = &test_dev->config; 713 714 return config_test_show_str(&test_dev->config_mutex, buf, 715 config->test_fs); 716 } 717 static DEVICE_ATTR_RW(config_test_fs); 718 719 static int trigger_config_run_type(struct kmod_test_device *test_dev, 720 enum kmod_test_case test_case, 721 const char *test_str) 722 { 723 int copied = 0; 724 struct test_config *config = &test_dev->config; 725 726 mutex_lock(&test_dev->config_mutex); 727 728 switch (test_case) { 729 case TEST_KMOD_DRIVER: 730 kfree_const(config->test_driver); 731 config->test_driver = NULL; 732 copied = config_copy_test_driver_name(config, test_str, 733 strlen(test_str)); 734 break; 735 case TEST_KMOD_FS_TYPE: 736 kfree_const(config->test_fs); 737 config->test_fs = NULL; 738 copied = config_copy_test_fs(config, test_str, 739 strlen(test_str)); 740 break; 741 default: 742 mutex_unlock(&test_dev->config_mutex); 743 return -EINVAL; 744 } 745 746 config->test_case = test_case; 747 748 mutex_unlock(&test_dev->config_mutex); 749 750 if (copied <= 0 || copied != strlen(test_str)) { 751 test_dev->test_is_oom = true; 752 return -ENOMEM; 753 } 754 755 test_dev->test_is_oom = false; 756 757 return trigger_config_run(test_dev); 758 } 759 760 static void free_test_dev_info(struct kmod_test_device *test_dev) 761 { 762 vfree(test_dev->info); 763 test_dev->info = NULL; 764 } 765 766 static int kmod_config_sync_info(struct kmod_test_device *test_dev) 767 { 768 struct test_config *config = &test_dev->config; 769 770 free_test_dev_info(test_dev); 771 test_dev->info = 772 vzalloc(array_size(sizeof(struct kmod_test_device_info), 773 config->num_threads)); 774 if (!test_dev->info) 775 return -ENOMEM; 776 777 return 0; 778 } 779 780 /* 781 * Old kernels may not have this, if you want to port this code to 782 * test it on older kernels. 783 */ 784 #ifdef get_kmod_umh_limit 785 static unsigned int kmod_init_test_thread_limit(void) 786 { 787 return get_kmod_umh_limit(); 788 } 789 #else 790 static unsigned int kmod_init_test_thread_limit(void) 791 { 792 return TEST_START_NUM_THREADS; 793 } 794 #endif 795 796 static int __kmod_config_init(struct kmod_test_device *test_dev) 797 { 798 struct test_config *config = &test_dev->config; 799 int ret = -ENOMEM, copied; 800 801 __kmod_config_free(config); 802 803 copied = config_copy_test_driver_name(config, TEST_START_DRIVER, 804 strlen(TEST_START_DRIVER)); 805 if (copied != strlen(TEST_START_DRIVER)) 806 goto err_out; 807 808 copied = config_copy_test_fs(config, TEST_START_TEST_FS, 809 strlen(TEST_START_TEST_FS)); 810 if (copied != strlen(TEST_START_TEST_FS)) 811 goto err_out; 812 813 config->num_threads = kmod_init_test_thread_limit(); 814 config->test_result = 0; 815 config->test_case = TEST_START_TEST_CASE; 816 817 ret = kmod_config_sync_info(test_dev); 818 if (ret) 819 goto err_out; 820 821 test_dev->test_is_oom = false; 822 823 return 0; 824 825 err_out: 826 test_dev->test_is_oom = true; 827 WARN_ON(test_dev->test_is_oom); 828 829 __kmod_config_free(config); 830 831 return ret; 832 } 833 834 static ssize_t reset_store(struct device *dev, 835 struct device_attribute *attr, 836 const char *buf, size_t count) 837 { 838 struct kmod_test_device *test_dev = dev_to_test_dev(dev); 839 int ret; 840 841 mutex_lock(&test_dev->trigger_mutex); 842 mutex_lock(&test_dev->config_mutex); 843 844 ret = __kmod_config_init(test_dev); 845 if (ret < 0) { 846 ret = -ENOMEM; 847 dev_err(dev, "could not alloc settings for config trigger: %d\n", 848 ret); 849 goto out; 850 } 851 852 dev_info(dev, "reset\n"); 853 ret = count; 854 855 out: 856 mutex_unlock(&test_dev->config_mutex); 857 mutex_unlock(&test_dev->trigger_mutex); 858 859 return ret; 860 } 861 static DEVICE_ATTR_WO(reset); 862 863 static int test_dev_config_update_uint_sync(struct kmod_test_device *test_dev, 864 const char *buf, size_t size, 865 unsigned int *config, 866 int (*test_sync)(struct kmod_test_device *test_dev)) 867 { 868 int ret; 869 unsigned int val; 870 unsigned int old_val; 871 872 ret = kstrtouint(buf, 10, &val); 873 if (ret) 874 return ret; 875 876 mutex_lock(&test_dev->config_mutex); 877 878 old_val = *config; 879 *(unsigned int *)config = val; 880 881 ret = test_sync(test_dev); 882 if (ret) { 883 *(unsigned int *)config = old_val; 884 885 ret = test_sync(test_dev); 886 WARN_ON(ret); 887 888 mutex_unlock(&test_dev->config_mutex); 889 return -EINVAL; 890 } 891 892 mutex_unlock(&test_dev->config_mutex); 893 /* Always return full write size even if we didn't consume all */ 894 return size; 895 } 896 897 static int test_dev_config_update_uint_range(struct kmod_test_device *test_dev, 898 const char *buf, size_t size, 899 unsigned int *config, 900 unsigned int min, 901 unsigned int max) 902 { 903 unsigned int val; 904 int ret; 905 906 ret = kstrtouint(buf, 10, &val); 907 if (ret) 908 return ret; 909 910 if (val < min || val > max) 911 return -EINVAL; 912 913 mutex_lock(&test_dev->config_mutex); 914 *config = val; 915 mutex_unlock(&test_dev->config_mutex); 916 917 /* Always return full write size even if we didn't consume all */ 918 return size; 919 } 920 921 static int test_dev_config_update_int(struct kmod_test_device *test_dev, 922 const char *buf, size_t size, 923 int *config) 924 { 925 int val; 926 int ret; 927 928 ret = kstrtoint(buf, 10, &val); 929 if (ret) 930 return ret; 931 932 mutex_lock(&test_dev->config_mutex); 933 *config = val; 934 mutex_unlock(&test_dev->config_mutex); 935 /* Always return full write size even if we didn't consume all */ 936 return size; 937 } 938 939 static ssize_t test_dev_config_show_int(struct kmod_test_device *test_dev, 940 char *buf, 941 int config) 942 { 943 int val; 944 945 mutex_lock(&test_dev->config_mutex); 946 val = config; 947 mutex_unlock(&test_dev->config_mutex); 948 949 return snprintf(buf, PAGE_SIZE, "%d\n", val); 950 } 951 952 static ssize_t test_dev_config_show_uint(struct kmod_test_device *test_dev, 953 char *buf, 954 unsigned int config) 955 { 956 unsigned int val; 957 958 mutex_lock(&test_dev->config_mutex); 959 val = config; 960 mutex_unlock(&test_dev->config_mutex); 961 962 return snprintf(buf, PAGE_SIZE, "%u\n", val); 963 } 964 965 static ssize_t test_result_store(struct device *dev, 966 struct device_attribute *attr, 967 const char *buf, size_t count) 968 { 969 struct kmod_test_device *test_dev = dev_to_test_dev(dev); 970 struct test_config *config = &test_dev->config; 971 972 return test_dev_config_update_int(test_dev, buf, count, 973 &config->test_result); 974 } 975 976 static ssize_t config_num_threads_store(struct device *dev, 977 struct device_attribute *attr, 978 const char *buf, size_t count) 979 { 980 struct kmod_test_device *test_dev = dev_to_test_dev(dev); 981 struct test_config *config = &test_dev->config; 982 983 return test_dev_config_update_uint_sync(test_dev, buf, count, 984 &config->num_threads, 985 kmod_config_sync_info); 986 } 987 988 static ssize_t config_num_threads_show(struct device *dev, 989 struct device_attribute *attr, 990 char *buf) 991 { 992 struct kmod_test_device *test_dev = dev_to_test_dev(dev); 993 struct test_config *config = &test_dev->config; 994 995 return test_dev_config_show_int(test_dev, buf, config->num_threads); 996 } 997 static DEVICE_ATTR_RW(config_num_threads); 998 999 static ssize_t config_test_case_store(struct device *dev, 1000 struct device_attribute *attr, 1001 const char *buf, size_t count) 1002 { 1003 struct kmod_test_device *test_dev = dev_to_test_dev(dev); 1004 struct test_config *config = &test_dev->config; 1005 1006 return test_dev_config_update_uint_range(test_dev, buf, count, 1007 &config->test_case, 1008 __TEST_KMOD_INVALID + 1, 1009 __TEST_KMOD_MAX - 1); 1010 } 1011 1012 static ssize_t config_test_case_show(struct device *dev, 1013 struct device_attribute *attr, 1014 char *buf) 1015 { 1016 struct kmod_test_device *test_dev = dev_to_test_dev(dev); 1017 struct test_config *config = &test_dev->config; 1018 1019 return test_dev_config_show_uint(test_dev, buf, config->test_case); 1020 } 1021 static DEVICE_ATTR_RW(config_test_case); 1022 1023 static ssize_t test_result_show(struct device *dev, 1024 struct device_attribute *attr, 1025 char *buf) 1026 { 1027 struct kmod_test_device *test_dev = dev_to_test_dev(dev); 1028 struct test_config *config = &test_dev->config; 1029 1030 return test_dev_config_show_int(test_dev, buf, config->test_result); 1031 } 1032 static DEVICE_ATTR_RW(test_result); 1033 1034 #define TEST_KMOD_DEV_ATTR(name) &dev_attr_##name.attr 1035 1036 static struct attribute *test_dev_attrs[] = { 1037 TEST_KMOD_DEV_ATTR(trigger_config), 1038 TEST_KMOD_DEV_ATTR(config), 1039 TEST_KMOD_DEV_ATTR(reset), 1040 1041 TEST_KMOD_DEV_ATTR(config_test_driver), 1042 TEST_KMOD_DEV_ATTR(config_test_fs), 1043 TEST_KMOD_DEV_ATTR(config_num_threads), 1044 TEST_KMOD_DEV_ATTR(config_test_case), 1045 TEST_KMOD_DEV_ATTR(test_result), 1046 1047 NULL, 1048 }; 1049 1050 ATTRIBUTE_GROUPS(test_dev); 1051 1052 static int kmod_config_init(struct kmod_test_device *test_dev) 1053 { 1054 int ret; 1055 1056 mutex_lock(&test_dev->config_mutex); 1057 ret = __kmod_config_init(test_dev); 1058 mutex_unlock(&test_dev->config_mutex); 1059 1060 return ret; 1061 } 1062 1063 static struct kmod_test_device *alloc_test_dev_kmod(int idx) 1064 { 1065 int ret; 1066 struct kmod_test_device *test_dev; 1067 struct miscdevice *misc_dev; 1068 1069 test_dev = vzalloc(sizeof(struct kmod_test_device)); 1070 if (!test_dev) 1071 goto err_out; 1072 1073 mutex_init(&test_dev->config_mutex); 1074 mutex_init(&test_dev->trigger_mutex); 1075 mutex_init(&test_dev->thread_mutex); 1076 1077 init_completion(&test_dev->kthreads_done); 1078 1079 ret = kmod_config_init(test_dev); 1080 if (ret < 0) { 1081 pr_err("Cannot alloc kmod_config_init()\n"); 1082 goto err_out_free; 1083 } 1084 1085 test_dev->dev_idx = idx; 1086 misc_dev = &test_dev->misc_dev; 1087 1088 misc_dev->minor = MISC_DYNAMIC_MINOR; 1089 misc_dev->name = kasprintf(GFP_KERNEL, "test_kmod%d", idx); 1090 if (!misc_dev->name) { 1091 pr_err("Cannot alloc misc_dev->name\n"); 1092 goto err_out_free_config; 1093 } 1094 misc_dev->groups = test_dev_groups; 1095 1096 return test_dev; 1097 1098 err_out_free_config: 1099 free_test_dev_info(test_dev); 1100 kmod_config_free(test_dev); 1101 err_out_free: 1102 vfree(test_dev); 1103 test_dev = NULL; 1104 err_out: 1105 return NULL; 1106 } 1107 1108 static void free_test_dev_kmod(struct kmod_test_device *test_dev) 1109 { 1110 if (test_dev) { 1111 kfree_const(test_dev->misc_dev.name); 1112 test_dev->misc_dev.name = NULL; 1113 free_test_dev_info(test_dev); 1114 kmod_config_free(test_dev); 1115 vfree(test_dev); 1116 test_dev = NULL; 1117 } 1118 } 1119 1120 static struct kmod_test_device *register_test_dev_kmod(void) 1121 { 1122 struct kmod_test_device *test_dev = NULL; 1123 int ret; 1124 1125 mutex_lock(®_dev_mutex); 1126 1127 /* int should suffice for number of devices, test for wrap */ 1128 if (num_test_devs + 1 == INT_MAX) { 1129 pr_err("reached limit of number of test devices\n"); 1130 goto out; 1131 } 1132 1133 test_dev = alloc_test_dev_kmod(num_test_devs); 1134 if (!test_dev) 1135 goto out; 1136 1137 ret = misc_register(&test_dev->misc_dev); 1138 if (ret) { 1139 pr_err("could not register misc device: %d\n", ret); 1140 free_test_dev_kmod(test_dev); 1141 test_dev = NULL; 1142 goto out; 1143 } 1144 1145 test_dev->dev = test_dev->misc_dev.this_device; 1146 list_add_tail(&test_dev->list, ®_test_devs); 1147 dev_info(test_dev->dev, "interface ready\n"); 1148 1149 num_test_devs++; 1150 1151 out: 1152 mutex_unlock(®_dev_mutex); 1153 1154 return test_dev; 1155 1156 } 1157 1158 static int __init test_kmod_init(void) 1159 { 1160 struct kmod_test_device *test_dev; 1161 int ret; 1162 1163 test_dev = register_test_dev_kmod(); 1164 if (!test_dev) { 1165 pr_err("Cannot add first test kmod device\n"); 1166 return -ENODEV; 1167 } 1168 1169 /* 1170 * With some work we might be able to gracefully enable 1171 * testing with this driver built-in, for now this seems 1172 * rather risky. For those willing to try have at it, 1173 * and enable the below. Good luck! If that works, try 1174 * lowering the init level for more fun. 1175 */ 1176 if (force_init_test) { 1177 ret = trigger_config_run_type(test_dev, 1178 TEST_KMOD_DRIVER, "tun"); 1179 if (WARN_ON(ret)) 1180 return ret; 1181 ret = trigger_config_run_type(test_dev, 1182 TEST_KMOD_FS_TYPE, "btrfs"); 1183 if (WARN_ON(ret)) 1184 return ret; 1185 } 1186 1187 return 0; 1188 } 1189 late_initcall(test_kmod_init); 1190 1191 static 1192 void unregister_test_dev_kmod(struct kmod_test_device *test_dev) 1193 { 1194 mutex_lock(&test_dev->trigger_mutex); 1195 mutex_lock(&test_dev->config_mutex); 1196 1197 test_dev_kmod_stop_tests(test_dev); 1198 1199 dev_info(test_dev->dev, "removing interface\n"); 1200 misc_deregister(&test_dev->misc_dev); 1201 1202 mutex_unlock(&test_dev->config_mutex); 1203 mutex_unlock(&test_dev->trigger_mutex); 1204 1205 free_test_dev_kmod(test_dev); 1206 } 1207 1208 static void __exit test_kmod_exit(void) 1209 { 1210 struct kmod_test_device *test_dev, *tmp; 1211 1212 mutex_lock(®_dev_mutex); 1213 list_for_each_entry_safe(test_dev, tmp, ®_test_devs, list) { 1214 list_del(&test_dev->list); 1215 unregister_test_dev_kmod(test_dev); 1216 } 1217 mutex_unlock(®_dev_mutex); 1218 } 1219 module_exit(test_kmod_exit); 1220 1221 MODULE_AUTHOR("Luis R. Rodriguez <mcgrof@kernel.org>"); 1222 MODULE_LICENSE("GPL"); 1223