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 35static bool force_init_test = false; 36module_param(force_init_test, bool_enable_only, 0644); 37MODULE_PARM_DESC(force_init_test, 38 "Force kicking a test immediately after driver loads"); 39 40/* 41 * For device allocation / registration 42 */ 43static DEFINE_MUTEX(reg_dev_mutex); 44static 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 */ 50static 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 */ 60enum kmod_test_case { 61 /* private: */ 62 __TEST_KMOD_INVALID = 0, 63 /* public: */ 64 65 TEST_KMOD_DRIVER, 66 TEST_KMOD_FS_TYPE, 67 68 /* private: */ 69 __TEST_KMOD_MAX, 70}; 71 72struct test_config { 73 char *test_driver; 74 char *test_fs; 75 unsigned int num_threads; 76 enum kmod_test_case test_case; 77 int test_result; 78}; 79 80struct kmod_test_device; 81 82/** 83 * struct kmod_test_device_info - thread info 84 * 85 * @ret_sync: return value if request_module() is used, sync request for 86 * @TEST_KMOD_DRIVER 87 * @fs_sync: return value of get_fs_type() for @TEST_KMOD_FS_TYPE 88 * @task_sync: kthread's task_struct or %NULL if not running 89 * @thread_idx: thread ID 90 * @test_dev: test device test is being performed under 91 * @need_mod_put: Some tests (get_fs_type() is one) requires putting the module 92 * (module_put(fs_sync->owner)) when done, otherwise you will not be able 93 * to unload the respective modules and re-test. We use this to keep 94 * accounting of when we need this and to help out in case we need to 95 * error out and deal with module_put() on error. 96 */ 97struct kmod_test_device_info { 98 int ret_sync; 99 struct file_system_type *fs_sync; 100 struct task_struct *task_sync; 101 unsigned int thread_idx; 102 struct kmod_test_device *test_dev; 103 bool need_mod_put; 104}; 105 106/** 107 * struct kmod_test_device - test device to help test kmod 108 * 109 * @dev_idx: unique ID for test device 110 * @config: configuration for the test 111 * @misc_dev: we use a misc device under the hood 112 * @dev: pointer to misc_dev's own struct device 113 * @config_mutex: protects configuration of test 114 * @trigger_mutex: the test trigger can only be fired once at a time 115 * @thread_mutex: protects @done count, and the @info per each thread 116 * @done: number of threads which have completed or failed 117 * @test_is_oom: when we run out of memory, use this to halt moving forward 118 * @kthreads_done: completion used to signal when all work is done 119 * @list: needed to be part of the reg_test_devs 120 * @info: array of info for each thread 121 */ 122struct kmod_test_device { 123 int dev_idx; 124 struct test_config config; 125 struct miscdevice misc_dev; 126 struct device *dev; 127 struct mutex config_mutex; 128 struct mutex trigger_mutex; 129 struct mutex thread_mutex; 130 131 unsigned int done; 132 133 bool test_is_oom; 134 struct completion kthreads_done; 135 struct list_head list; 136 137 struct kmod_test_device_info *info; 138}; 139 140static const char *test_case_str(enum kmod_test_case test_case) 141{ 142 switch (test_case) { 143 case TEST_KMOD_DRIVER: 144 return "TEST_KMOD_DRIVER"; 145 case TEST_KMOD_FS_TYPE: 146 return "TEST_KMOD_FS_TYPE"; 147 default: 148 return "invalid"; 149 } 150} 151 152static struct miscdevice *dev_to_misc_dev(struct device *dev) 153{ 154 return dev_get_drvdata(dev); 155} 156 157static struct kmod_test_device *misc_dev_to_test_dev(struct miscdevice *misc_dev) 158{ 159 return container_of(misc_dev, struct kmod_test_device, misc_dev); 160} 161 162static struct kmod_test_device *dev_to_test_dev(struct device *dev) 163{ 164 struct miscdevice *misc_dev; 165 166 misc_dev = dev_to_misc_dev(dev); 167 168 return misc_dev_to_test_dev(misc_dev); 169} 170 171/* Must run with thread_mutex held */ 172static void kmod_test_done_check(struct kmod_test_device *test_dev, 173 unsigned int idx) 174{ 175 struct test_config *config = &test_dev->config; 176 177 test_dev->done++; 178 dev_dbg(test_dev->dev, "Done thread count: %u\n", test_dev->done); 179 180 if (test_dev->done == config->num_threads) { 181 dev_info(test_dev->dev, "Done: %u threads have all run now\n", 182 test_dev->done); 183 dev_info(test_dev->dev, "Last thread to run: %u\n", idx); 184 complete(&test_dev->kthreads_done); 185 } 186} 187 188static void test_kmod_put_module(struct kmod_test_device_info *info) 189{ 190 struct kmod_test_device *test_dev = info->test_dev; 191 struct test_config *config = &test_dev->config; 192 193 if (!info->need_mod_put) 194 return; 195 196 switch (config->test_case) { 197 case TEST_KMOD_DRIVER: 198 break; 199 case TEST_KMOD_FS_TYPE: 200 if (info->fs_sync && info->fs_sync->owner) 201 module_put(info->fs_sync->owner); 202 break; 203 default: 204 BUG(); 205 } 206 207 info->need_mod_put = true; 208} 209 210static int run_request(void *data) 211{ 212 struct kmod_test_device_info *info = data; 213 struct kmod_test_device *test_dev = info->test_dev; 214 struct test_config *config = &test_dev->config; 215 216 switch (config->test_case) { 217 case TEST_KMOD_DRIVER: 218 info->ret_sync = request_module("%s", config->test_driver); 219 break; 220 case TEST_KMOD_FS_TYPE: 221 info->fs_sync = get_fs_type(config->test_fs); 222 info->need_mod_put = true; 223 break; 224 default: 225 /* __trigger_config_run() already checked for test sanity */ 226 BUG(); 227 return -EINVAL; 228 } 229 230 dev_dbg(test_dev->dev, "Ran thread %u\n", info->thread_idx); 231 232 test_kmod_put_module(info); 233 234 mutex_lock(&test_dev->thread_mutex); 235 info->task_sync = NULL; 236 kmod_test_done_check(test_dev, info->thread_idx); 237 mutex_unlock(&test_dev->thread_mutex); 238 239 return 0; 240} 241 242static int tally_work_test(struct kmod_test_device_info *info) 243{ 244 struct kmod_test_device *test_dev = info->test_dev; 245 struct test_config *config = &test_dev->config; 246 int err_ret = 0; 247 248 switch (config->test_case) { 249 case TEST_KMOD_DRIVER: 250 /* 251 * Only capture errors, if one is found that's 252 * enough, for now. 253 */ 254 if (info->ret_sync != 0) 255 err_ret = info->ret_sync; 256 dev_info(test_dev->dev, 257 "Sync thread %d return status: %d\n", 258 info->thread_idx, info->ret_sync); 259 break; 260 case TEST_KMOD_FS_TYPE: 261 /* For now we make this simple */ 262 if (!info->fs_sync) 263 err_ret = -EINVAL; 264 dev_info(test_dev->dev, "Sync thread %u fs: %s\n", 265 info->thread_idx, info->fs_sync ? config->test_fs : 266 "NULL"); 267 break; 268 default: 269 BUG(); 270 } 271 272 return err_ret; 273} 274 275/* 276 * XXX: add result option to display if all errors did not match. 277 * For now we just keep any error code if one was found. 278 * 279 * If this ran it means *all* tasks were created fine and we 280 * are now just collecting results. 281 * 282 * Only propagate errors, do not override with a subsequent success case. 283 */ 284static void tally_up_work(struct kmod_test_device *test_dev) 285{ 286 struct test_config *config = &test_dev->config; 287 struct kmod_test_device_info *info; 288 unsigned int idx; 289 int err_ret = 0; 290 int ret = 0; 291 292 mutex_lock(&test_dev->thread_mutex); 293 294 dev_info(test_dev->dev, "Results:\n"); 295 296 for (idx=0; idx < config->num_threads; idx++) { 297 info = &test_dev->info[idx]; 298 ret = tally_work_test(info); 299 if (ret) 300 err_ret = ret; 301 } 302 303 /* 304 * Note: request_module() returns 256 for a module not found even 305 * though modprobe itself returns 1. 306 */ 307 config->test_result = err_ret; 308 309 mutex_unlock(&test_dev->thread_mutex); 310} 311 312static int try_one_request(struct kmod_test_device *test_dev, unsigned int idx) 313{ 314 struct kmod_test_device_info *info = &test_dev->info[idx]; 315 int fail_ret = -ENOMEM; 316 317 mutex_lock(&test_dev->thread_mutex); 318 319 info->thread_idx = idx; 320 info->test_dev = test_dev; 321 info->task_sync = kthread_run(run_request, info, "%s-%u", 322 KBUILD_MODNAME, idx); 323 324 if (!info->task_sync || IS_ERR(info->task_sync)) { 325 test_dev->test_is_oom = true; 326 dev_err(test_dev->dev, "Setting up thread %u failed\n", idx); 327 info->task_sync = NULL; 328 goto err_out; 329 } else 330 dev_dbg(test_dev->dev, "Kicked off thread %u\n", idx); 331 332 mutex_unlock(&test_dev->thread_mutex); 333 334 return 0; 335 336err_out: 337 info->ret_sync = fail_ret; 338 mutex_unlock(&test_dev->thread_mutex); 339 340 return fail_ret; 341} 342 343static void test_dev_kmod_stop_tests(struct kmod_test_device *test_dev) 344{ 345 struct test_config *config = &test_dev->config; 346 struct kmod_test_device_info *info; 347 unsigned int i; 348 349 dev_info(test_dev->dev, "Ending request_module() tests\n"); 350 351 mutex_lock(&test_dev->thread_mutex); 352 353 for (i=0; i < config->num_threads; i++) { 354 info = &test_dev->info[i]; 355 if (info->task_sync && !IS_ERR(info->task_sync)) { 356 dev_info(test_dev->dev, 357 "Stopping still-running thread %i\n", i); 358 kthread_stop(info->task_sync); 359 } 360 361 /* 362 * info->task_sync is well protected, it can only be 363 * NULL or a pointer to a struct. If its NULL we either 364 * never ran, or we did and we completed the work. Completed 365 * tasks *always* put the module for us. This is a sanity 366 * check -- just in case. 367 */ 368 if (info->task_sync && info->need_mod_put) 369 test_kmod_put_module(info); 370 } 371 372 mutex_unlock(&test_dev->thread_mutex); 373} 374 375/* 376 * Only wait *iff* we did not run into any errors during all of our thread 377 * set up. If run into any issues we stop threads and just bail out with 378 * an error to the trigger. This also means we don't need any tally work 379 * for any threads which fail. 380 */ 381static int try_requests(struct kmod_test_device *test_dev) 382{ 383 struct test_config *config = &test_dev->config; 384 unsigned int idx; 385 int ret; 386 bool any_error = false; 387 388 for (idx=0; idx < config->num_threads; idx++) { 389 if (test_dev->test_is_oom) { 390 any_error = true; 391 break; 392 } 393 394 ret = try_one_request(test_dev, idx); 395 if (ret) { 396 any_error = true; 397 break; 398 } 399 } 400 401 if (!any_error) { 402 test_dev->test_is_oom = false; 403 dev_info(test_dev->dev, 404 "No errors were found while initializing threads\n"); 405 wait_for_completion(&test_dev->kthreads_done); 406 tally_up_work(test_dev); 407 } else { 408 test_dev->test_is_oom = true; 409 dev_info(test_dev->dev, 410 "At least one thread failed to start, stop all work\n"); 411 test_dev_kmod_stop_tests(test_dev); 412 return -ENOMEM; 413 } 414 415 return 0; 416} 417 418static int run_test_driver(struct kmod_test_device *test_dev) 419{ 420 struct test_config *config = &test_dev->config; 421 422 dev_info(test_dev->dev, "Test case: %s (%u)\n", 423 test_case_str(config->test_case), 424 config->test_case); 425 dev_info(test_dev->dev, "Test driver to load: %s\n", 426 config->test_driver); 427 dev_info(test_dev->dev, "Number of threads to run: %u\n", 428 config->num_threads); 429 dev_info(test_dev->dev, "Thread IDs will range from 0 - %u\n", 430 config->num_threads - 1); 431 432 return try_requests(test_dev); 433} 434 435static int run_test_fs_type(struct kmod_test_device *test_dev) 436{ 437 struct test_config *config = &test_dev->config; 438 439 dev_info(test_dev->dev, "Test case: %s (%u)\n", 440 test_case_str(config->test_case), 441 config->test_case); 442 dev_info(test_dev->dev, "Test filesystem to load: %s\n", 443 config->test_fs); 444 dev_info(test_dev->dev, "Number of threads to run: %u\n", 445 config->num_threads); 446 dev_info(test_dev->dev, "Thread IDs will range from 0 - %u\n", 447 config->num_threads - 1); 448 449 return try_requests(test_dev); 450} 451 452static ssize_t config_show(struct device *dev, 453 struct device_attribute *attr, 454 char *buf) 455{ 456 struct kmod_test_device *test_dev = dev_to_test_dev(dev); 457 struct test_config *config = &test_dev->config; 458 int len = 0; 459 460 mutex_lock(&test_dev->config_mutex); 461 462 len += snprintf(buf, PAGE_SIZE, 463 "Custom trigger configuration for: %s\n", 464 dev_name(dev)); 465 466 len += snprintf(buf+len, PAGE_SIZE - len, 467 "Number of threads:\t%u\n", 468 config->num_threads); 469 470 len += snprintf(buf+len, PAGE_SIZE - len, 471 "Test_case:\t%s (%u)\n", 472 test_case_str(config->test_case), 473 config->test_case); 474 475 if (config->test_driver) 476 len += snprintf(buf+len, PAGE_SIZE - len, 477 "driver:\t%s\n", 478 config->test_driver); 479 else 480 len += snprintf(buf+len, PAGE_SIZE - len, 481 "driver:\tEMPTY\n"); 482 483 if (config->test_fs) 484 len += snprintf(buf+len, PAGE_SIZE - len, 485 "fs:\t%s\n", 486 config->test_fs); 487 else 488 len += snprintf(buf+len, PAGE_SIZE - len, 489 "fs:\tEMPTY\n"); 490 491 mutex_unlock(&test_dev->config_mutex); 492 493 return len; 494} 495static DEVICE_ATTR_RO(config); 496 497/* 498 * This ensures we don't allow kicking threads through if our configuration 499 * is faulty. 500 */ 501static int __trigger_config_run(struct kmod_test_device *test_dev) 502{ 503 struct test_config *config = &test_dev->config; 504 505 test_dev->done = 0; 506 507 switch (config->test_case) { 508 case TEST_KMOD_DRIVER: 509 return run_test_driver(test_dev); 510 case TEST_KMOD_FS_TYPE: 511 return run_test_fs_type(test_dev); 512 default: 513 dev_warn(test_dev->dev, 514 "Invalid test case requested: %u\n", 515 config->test_case); 516 return -EINVAL; 517 } 518} 519 520static int trigger_config_run(struct kmod_test_device *test_dev) 521{ 522 struct test_config *config = &test_dev->config; 523 int ret; 524 525 mutex_lock(&test_dev->trigger_mutex); 526 mutex_lock(&test_dev->config_mutex); 527 528 ret = __trigger_config_run(test_dev); 529 if (ret < 0) 530 goto out; 531 dev_info(test_dev->dev, "General test result: %d\n", 532 config->test_result); 533 534 /* 535 * We must return 0 after a trigger even unless something went 536 * wrong with the setup of the test. If the test setup went fine 537 * then userspace must just check the result of config->test_result. 538 * One issue with relying on the return from a call in the kernel 539 * is if the kernel returns a positive value using this trigger 540 * will not return the value to userspace, it would be lost. 541 * 542 * By not relying on capturing the return value of tests we are using 543 * through the trigger it also us to run tests with set -e and only 544 * fail when something went wrong with the driver upon trigger 545 * requests. 546 */ 547 ret = 0; 548 549out: 550 mutex_unlock(&test_dev->config_mutex); 551 mutex_unlock(&test_dev->trigger_mutex); 552 553 return ret; 554} 555 556static ssize_t 557trigger_config_store(struct device *dev, 558 struct device_attribute *attr, 559 const char *buf, size_t count) 560{ 561 struct kmod_test_device *test_dev = dev_to_test_dev(dev); 562 int ret; 563 564 if (test_dev->test_is_oom) 565 return -ENOMEM; 566 567 /* For all intents and purposes we don't care what userspace 568 * sent this trigger, we care only that we were triggered. 569 * We treat the return value only for caputuring issues with 570 * the test setup. At this point all the test variables should 571 * have been allocated so typically this should never fail. 572 */ 573 ret = trigger_config_run(test_dev); 574 if (unlikely(ret < 0)) 575 goto out; 576 577 /* 578 * Note: any return > 0 will be treated as success 579 * and the error value will not be available to userspace. 580 * Do not rely on trying to send to userspace a test value 581 * return value as positive return errors will be lost. 582 */ 583 if (WARN_ON(ret > 0)) 584 return -EINVAL; 585 586 ret = count; 587out: 588 return ret; 589} 590static DEVICE_ATTR_WO(trigger_config); 591 592/* 593 * XXX: move to kstrncpy() once merged. 594 * 595 * Users should use kfree_const() when freeing these. 596 */ 597static int __kstrncpy(char **dst, const char *name, size_t count, gfp_t gfp) 598{ 599 *dst = kstrndup(name, count, gfp); 600 if (!*dst) 601 return -ENOSPC; 602 return count; 603} 604 605static int config_copy_test_driver_name(struct test_config *config, 606 const char *name, 607 size_t count) 608{ 609 return __kstrncpy(&config->test_driver, name, count, GFP_KERNEL); 610} 611 612 613static int config_copy_test_fs(struct test_config *config, const char *name, 614 size_t count) 615{ 616 return __kstrncpy(&config->test_fs, name, count, GFP_KERNEL); 617} 618 619static void __kmod_config_free(struct test_config *config) 620{ 621 if (!config) 622 return; 623 624 kfree_const(config->test_driver); 625 config->test_driver = NULL; 626 627 kfree_const(config->test_fs); 628 config->test_fs = NULL; 629} 630 631static void kmod_config_free(struct kmod_test_device *test_dev) 632{ 633 struct test_config *config; 634 635 if (!test_dev) 636 return; 637 638 config = &test_dev->config; 639 640 mutex_lock(&test_dev->config_mutex); 641 __kmod_config_free(config); 642 mutex_unlock(&test_dev->config_mutex); 643} 644 645static ssize_t config_test_driver_store(struct device *dev, 646 struct device_attribute *attr, 647 const char *buf, size_t count) 648{ 649 struct kmod_test_device *test_dev = dev_to_test_dev(dev); 650 struct test_config *config = &test_dev->config; 651 int copied; 652 653 mutex_lock(&test_dev->config_mutex); 654 655 kfree_const(config->test_driver); 656 config->test_driver = NULL; 657 658 copied = config_copy_test_driver_name(config, buf, count); 659 mutex_unlock(&test_dev->config_mutex); 660 661 return copied; 662} 663 664/* 665 * As per sysfs_kf_seq_show() the buf is max PAGE_SIZE. 666 */ 667static ssize_t config_test_show_str(struct mutex *config_mutex, 668 char *dst, 669 char *src) 670{ 671 int len; 672 673 mutex_lock(config_mutex); 674 len = snprintf(dst, PAGE_SIZE, "%s\n", src); 675 mutex_unlock(config_mutex); 676 677 return len; 678} 679 680static ssize_t config_test_driver_show(struct device *dev, 681 struct device_attribute *attr, 682 char *buf) 683{ 684 struct kmod_test_device *test_dev = dev_to_test_dev(dev); 685 struct test_config *config = &test_dev->config; 686 687 return config_test_show_str(&test_dev->config_mutex, buf, 688 config->test_driver); 689} 690static DEVICE_ATTR_RW(config_test_driver); 691 692static ssize_t config_test_fs_store(struct device *dev, 693 struct device_attribute *attr, 694 const char *buf, size_t count) 695{ 696 struct kmod_test_device *test_dev = dev_to_test_dev(dev); 697 struct test_config *config = &test_dev->config; 698 int copied; 699 700 mutex_lock(&test_dev->config_mutex); 701 702 kfree_const(config->test_fs); 703 config->test_fs = NULL; 704 705 copied = config_copy_test_fs(config, buf, count); 706 mutex_unlock(&test_dev->config_mutex); 707 708 return copied; 709} 710 711static ssize_t config_test_fs_show(struct device *dev, 712 struct device_attribute *attr, 713 char *buf) 714{ 715 struct kmod_test_device *test_dev = dev_to_test_dev(dev); 716 struct test_config *config = &test_dev->config; 717 718 return config_test_show_str(&test_dev->config_mutex, buf, 719 config->test_fs); 720} 721static DEVICE_ATTR_RW(config_test_fs); 722 723static int trigger_config_run_type(struct kmod_test_device *test_dev, 724 enum kmod_test_case test_case, 725 const char *test_str) 726{ 727 int copied = 0; 728 struct test_config *config = &test_dev->config; 729 730 mutex_lock(&test_dev->config_mutex); 731 732 switch (test_case) { 733 case TEST_KMOD_DRIVER: 734 kfree_const(config->test_driver); 735 config->test_driver = NULL; 736 copied = config_copy_test_driver_name(config, test_str, 737 strlen(test_str)); 738 break; 739 case TEST_KMOD_FS_TYPE: 740 kfree_const(config->test_fs); 741 config->test_fs = NULL; 742 copied = config_copy_test_fs(config, test_str, 743 strlen(test_str)); 744 break; 745 default: 746 mutex_unlock(&test_dev->config_mutex); 747 return -EINVAL; 748 } 749 750 config->test_case = test_case; 751 752 mutex_unlock(&test_dev->config_mutex); 753 754 if (copied <= 0 || copied != strlen(test_str)) { 755 test_dev->test_is_oom = true; 756 return -ENOMEM; 757 } 758 759 test_dev->test_is_oom = false; 760 761 return trigger_config_run(test_dev); 762} 763 764static void free_test_dev_info(struct kmod_test_device *test_dev) 765{ 766 vfree(test_dev->info); 767 test_dev->info = NULL; 768} 769 770static int kmod_config_sync_info(struct kmod_test_device *test_dev) 771{ 772 struct test_config *config = &test_dev->config; 773 774 free_test_dev_info(test_dev); 775 test_dev->info = 776 vzalloc(array_size(sizeof(struct kmod_test_device_info), 777 config->num_threads)); 778 if (!test_dev->info) 779 return -ENOMEM; 780 781 return 0; 782} 783 784/* 785 * Old kernels may not have this, if you want to port this code to 786 * test it on older kernels. 787 */ 788#ifdef get_kmod_umh_limit 789static unsigned int kmod_init_test_thread_limit(void) 790{ 791 return get_kmod_umh_limit(); 792} 793#else 794static unsigned int kmod_init_test_thread_limit(void) 795{ 796 return TEST_START_NUM_THREADS; 797} 798#endif 799 800static int __kmod_config_init(struct kmod_test_device *test_dev) 801{ 802 struct test_config *config = &test_dev->config; 803 int ret = -ENOMEM, copied; 804 805 __kmod_config_free(config); 806 807 copied = config_copy_test_driver_name(config, TEST_START_DRIVER, 808 strlen(TEST_START_DRIVER)); 809 if (copied != strlen(TEST_START_DRIVER)) 810 goto err_out; 811 812 copied = config_copy_test_fs(config, TEST_START_TEST_FS, 813 strlen(TEST_START_TEST_FS)); 814 if (copied != strlen(TEST_START_TEST_FS)) 815 goto err_out; 816 817 config->num_threads = kmod_init_test_thread_limit(); 818 config->test_result = 0; 819 config->test_case = TEST_START_TEST_CASE; 820 821 ret = kmod_config_sync_info(test_dev); 822 if (ret) 823 goto err_out; 824 825 test_dev->test_is_oom = false; 826 827 return 0; 828 829err_out: 830 test_dev->test_is_oom = true; 831 WARN_ON(test_dev->test_is_oom); 832 833 __kmod_config_free(config); 834 835 return ret; 836} 837 838static ssize_t reset_store(struct device *dev, 839 struct device_attribute *attr, 840 const char *buf, size_t count) 841{ 842 struct kmod_test_device *test_dev = dev_to_test_dev(dev); 843 int ret; 844 845 mutex_lock(&test_dev->trigger_mutex); 846 mutex_lock(&test_dev->config_mutex); 847 848 ret = __kmod_config_init(test_dev); 849 if (ret < 0) { 850 ret = -ENOMEM; 851 dev_err(dev, "could not alloc settings for config trigger: %d\n", 852 ret); 853 goto out; 854 } 855 856 dev_info(dev, "reset\n"); 857 ret = count; 858 859out: 860 mutex_unlock(&test_dev->config_mutex); 861 mutex_unlock(&test_dev->trigger_mutex); 862 863 return ret; 864} 865static DEVICE_ATTR_WO(reset); 866 867static int test_dev_config_update_uint_sync(struct kmod_test_device *test_dev, 868 const char *buf, size_t size, 869 unsigned int *config, 870 int (*test_sync)(struct kmod_test_device *test_dev)) 871{ 872 int ret; 873 unsigned int val; 874 unsigned int old_val; 875 876 ret = kstrtouint(buf, 10, &val); 877 if (ret) 878 return ret; 879 880 mutex_lock(&test_dev->config_mutex); 881 882 old_val = *config; 883 *(unsigned int *)config = val; 884 885 ret = test_sync(test_dev); 886 if (ret) { 887 *(unsigned int *)config = old_val; 888 889 ret = test_sync(test_dev); 890 WARN_ON(ret); 891 892 mutex_unlock(&test_dev->config_mutex); 893 return -EINVAL; 894 } 895 896 mutex_unlock(&test_dev->config_mutex); 897 /* Always return full write size even if we didn't consume all */ 898 return size; 899} 900 901static int test_dev_config_update_uint_range(struct kmod_test_device *test_dev, 902 const char *buf, size_t size, 903 unsigned int *config, 904 unsigned int min, 905 unsigned int max) 906{ 907 unsigned int val; 908 int ret; 909 910 ret = kstrtouint(buf, 10, &val); 911 if (ret) 912 return ret; 913 914 if (val < min || val > max) 915 return -EINVAL; 916 917 mutex_lock(&test_dev->config_mutex); 918 *config = val; 919 mutex_unlock(&test_dev->config_mutex); 920 921 /* Always return full write size even if we didn't consume all */ 922 return size; 923} 924 925static int test_dev_config_update_int(struct kmod_test_device *test_dev, 926 const char *buf, size_t size, 927 int *config) 928{ 929 int val; 930 int ret; 931 932 ret = kstrtoint(buf, 10, &val); 933 if (ret) 934 return ret; 935 936 mutex_lock(&test_dev->config_mutex); 937 *config = val; 938 mutex_unlock(&test_dev->config_mutex); 939 /* Always return full write size even if we didn't consume all */ 940 return size; 941} 942 943static ssize_t test_dev_config_show_int(struct kmod_test_device *test_dev, 944 char *buf, 945 int config) 946{ 947 int val; 948 949 mutex_lock(&test_dev->config_mutex); 950 val = config; 951 mutex_unlock(&test_dev->config_mutex); 952 953 return snprintf(buf, PAGE_SIZE, "%d\n", val); 954} 955 956static ssize_t test_dev_config_show_uint(struct kmod_test_device *test_dev, 957 char *buf, 958 unsigned int config) 959{ 960 unsigned int val; 961 962 mutex_lock(&test_dev->config_mutex); 963 val = config; 964 mutex_unlock(&test_dev->config_mutex); 965 966 return snprintf(buf, PAGE_SIZE, "%u\n", val); 967} 968 969static ssize_t test_result_store(struct device *dev, 970 struct device_attribute *attr, 971 const char *buf, size_t count) 972{ 973 struct kmod_test_device *test_dev = dev_to_test_dev(dev); 974 struct test_config *config = &test_dev->config; 975 976 return test_dev_config_update_int(test_dev, buf, count, 977 &config->test_result); 978} 979 980static ssize_t config_num_threads_store(struct device *dev, 981 struct device_attribute *attr, 982 const char *buf, size_t count) 983{ 984 struct kmod_test_device *test_dev = dev_to_test_dev(dev); 985 struct test_config *config = &test_dev->config; 986 987 return test_dev_config_update_uint_sync(test_dev, buf, count, 988 &config->num_threads, 989 kmod_config_sync_info); 990} 991 992static ssize_t config_num_threads_show(struct device *dev, 993 struct device_attribute *attr, 994 char *buf) 995{ 996 struct kmod_test_device *test_dev = dev_to_test_dev(dev); 997 struct test_config *config = &test_dev->config; 998 999 return test_dev_config_show_int(test_dev, buf, config->num_threads); 1000} 1001static DEVICE_ATTR_RW(config_num_threads); 1002 1003static ssize_t config_test_case_store(struct device *dev, 1004 struct device_attribute *attr, 1005 const char *buf, size_t count) 1006{ 1007 struct kmod_test_device *test_dev = dev_to_test_dev(dev); 1008 struct test_config *config = &test_dev->config; 1009 1010 return test_dev_config_update_uint_range(test_dev, buf, count, 1011 &config->test_case, 1012 __TEST_KMOD_INVALID + 1, 1013 __TEST_KMOD_MAX - 1); 1014} 1015 1016static ssize_t config_test_case_show(struct device *dev, 1017 struct device_attribute *attr, 1018 char *buf) 1019{ 1020 struct kmod_test_device *test_dev = dev_to_test_dev(dev); 1021 struct test_config *config = &test_dev->config; 1022 1023 return test_dev_config_show_uint(test_dev, buf, config->test_case); 1024} 1025static DEVICE_ATTR_RW(config_test_case); 1026 1027static ssize_t test_result_show(struct device *dev, 1028 struct device_attribute *attr, 1029 char *buf) 1030{ 1031 struct kmod_test_device *test_dev = dev_to_test_dev(dev); 1032 struct test_config *config = &test_dev->config; 1033 1034 return test_dev_config_show_int(test_dev, buf, config->test_result); 1035} 1036static DEVICE_ATTR_RW(test_result); 1037 1038#define TEST_KMOD_DEV_ATTR(name) &dev_attr_##name.attr 1039 1040static struct attribute *test_dev_attrs[] = { 1041 TEST_KMOD_DEV_ATTR(trigger_config), 1042 TEST_KMOD_DEV_ATTR(config), 1043 TEST_KMOD_DEV_ATTR(reset), 1044 1045 TEST_KMOD_DEV_ATTR(config_test_driver), 1046 TEST_KMOD_DEV_ATTR(config_test_fs), 1047 TEST_KMOD_DEV_ATTR(config_num_threads), 1048 TEST_KMOD_DEV_ATTR(config_test_case), 1049 TEST_KMOD_DEV_ATTR(test_result), 1050 1051 NULL, 1052}; 1053 1054ATTRIBUTE_GROUPS(test_dev); 1055 1056static int kmod_config_init(struct kmod_test_device *test_dev) 1057{ 1058 int ret; 1059 1060 mutex_lock(&test_dev->config_mutex); 1061 ret = __kmod_config_init(test_dev); 1062 mutex_unlock(&test_dev->config_mutex); 1063 1064 return ret; 1065} 1066 1067static struct kmod_test_device *alloc_test_dev_kmod(int idx) 1068{ 1069 int ret; 1070 struct kmod_test_device *test_dev; 1071 struct miscdevice *misc_dev; 1072 1073 test_dev = vzalloc(sizeof(struct kmod_test_device)); 1074 if (!test_dev) 1075 goto err_out; 1076 1077 mutex_init(&test_dev->config_mutex); 1078 mutex_init(&test_dev->trigger_mutex); 1079 mutex_init(&test_dev->thread_mutex); 1080 1081 init_completion(&test_dev->kthreads_done); 1082 1083 ret = kmod_config_init(test_dev); 1084 if (ret < 0) { 1085 pr_err("Cannot alloc kmod_config_init()\n"); 1086 goto err_out_free; 1087 } 1088 1089 test_dev->dev_idx = idx; 1090 misc_dev = &test_dev->misc_dev; 1091 1092 misc_dev->minor = MISC_DYNAMIC_MINOR; 1093 misc_dev->name = kasprintf(GFP_KERNEL, "test_kmod%d", idx); 1094 if (!misc_dev->name) { 1095 pr_err("Cannot alloc misc_dev->name\n"); 1096 goto err_out_free_config; 1097 } 1098 misc_dev->groups = test_dev_groups; 1099 1100 return test_dev; 1101 1102err_out_free_config: 1103 free_test_dev_info(test_dev); 1104 kmod_config_free(test_dev); 1105err_out_free: 1106 vfree(test_dev); 1107 test_dev = NULL; 1108err_out: 1109 return NULL; 1110} 1111 1112static void free_test_dev_kmod(struct kmod_test_device *test_dev) 1113{ 1114 if (test_dev) { 1115 kfree_const(test_dev->misc_dev.name); 1116 test_dev->misc_dev.name = NULL; 1117 free_test_dev_info(test_dev); 1118 kmod_config_free(test_dev); 1119 vfree(test_dev); 1120 test_dev = NULL; 1121 } 1122} 1123 1124static struct kmod_test_device *register_test_dev_kmod(void) 1125{ 1126 struct kmod_test_device *test_dev = NULL; 1127 int ret; 1128 1129 mutex_lock(®_dev_mutex); 1130 1131 /* int should suffice for number of devices, test for wrap */ 1132 if (num_test_devs + 1 == INT_MAX) { 1133 pr_err("reached limit of number of test devices\n"); 1134 goto out; 1135 } 1136 1137 test_dev = alloc_test_dev_kmod(num_test_devs); 1138 if (!test_dev) 1139 goto out; 1140 1141 ret = misc_register(&test_dev->misc_dev); 1142 if (ret) { 1143 pr_err("could not register misc device: %d\n", ret); 1144 free_test_dev_kmod(test_dev); 1145 test_dev = NULL; 1146 goto out; 1147 } 1148 1149 test_dev->dev = test_dev->misc_dev.this_device; 1150 list_add_tail(&test_dev->list, ®_test_devs); 1151 dev_info(test_dev->dev, "interface ready\n"); 1152 1153 num_test_devs++; 1154 1155out: 1156 mutex_unlock(®_dev_mutex); 1157 1158 return test_dev; 1159 1160} 1161 1162static int __init test_kmod_init(void) 1163{ 1164 struct kmod_test_device *test_dev; 1165 int ret; 1166 1167 test_dev = register_test_dev_kmod(); 1168 if (!test_dev) { 1169 pr_err("Cannot add first test kmod device\n"); 1170 return -ENODEV; 1171 } 1172 1173 /* 1174 * With some work we might be able to gracefully enable 1175 * testing with this driver built-in, for now this seems 1176 * rather risky. For those willing to try have at it, 1177 * and enable the below. Good luck! If that works, try 1178 * lowering the init level for more fun. 1179 */ 1180 if (force_init_test) { 1181 ret = trigger_config_run_type(test_dev, 1182 TEST_KMOD_DRIVER, "tun"); 1183 if (WARN_ON(ret)) 1184 return ret; 1185 ret = trigger_config_run_type(test_dev, 1186 TEST_KMOD_FS_TYPE, "btrfs"); 1187 if (WARN_ON(ret)) 1188 return ret; 1189 } 1190 1191 return 0; 1192} 1193late_initcall(test_kmod_init); 1194 1195static 1196void unregister_test_dev_kmod(struct kmod_test_device *test_dev) 1197{ 1198 mutex_lock(&test_dev->trigger_mutex); 1199 mutex_lock(&test_dev->config_mutex); 1200 1201 test_dev_kmod_stop_tests(test_dev); 1202 1203 dev_info(test_dev->dev, "removing interface\n"); 1204 misc_deregister(&test_dev->misc_dev); 1205 1206 mutex_unlock(&test_dev->config_mutex); 1207 mutex_unlock(&test_dev->trigger_mutex); 1208 1209 free_test_dev_kmod(test_dev); 1210} 1211 1212static void __exit test_kmod_exit(void) 1213{ 1214 struct kmod_test_device *test_dev, *tmp; 1215 1216 mutex_lock(®_dev_mutex); 1217 list_for_each_entry_safe(test_dev, tmp, ®_test_devs, list) { 1218 list_del(&test_dev->list); 1219 unregister_test_dev_kmod(test_dev); 1220 } 1221 mutex_unlock(®_dev_mutex); 1222} 1223module_exit(test_kmod_exit); 1224 1225MODULE_AUTHOR("Luis R. Rodriguez <mcgrof@kernel.org>"); 1226MODULE_LICENSE("GPL"); 1227