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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 __TEST_KMOD_INVALID = 0,
62
63 TEST_KMOD_DRIVER,
64 TEST_KMOD_FS_TYPE,
65
66 __TEST_KMOD_MAX,
67};
68
69struct 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
77struct 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 */
93struct 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 */
118struct 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
136static 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
148static struct miscdevice *dev_to_misc_dev(struct device *dev)
149{
150 return dev_get_drvdata(dev);
151}
152
153static 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
158static 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 */
168static 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
184static 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
206static 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
238static 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 */
280static 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
308static 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
332err_out:
333 info->ret_sync = fail_ret;
334 mutex_unlock(&test_dev->thread_mutex);
335
336 return fail_ret;
337}
338
339static 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 */
377static 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
414static 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
431static 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
448static 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}
491static DEVICE_ATTR_RO(config);
492
493/*
494 * This ensures we don't allow kicking threads through if our configuration
495 * is faulty.
496 */
497static 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
516static 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
545out:
546 mutex_unlock(&test_dev->config_mutex);
547 mutex_unlock(&test_dev->trigger_mutex);
548
549 return ret;
550}
551
552static ssize_t
553trigger_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;
583out:
584 return ret;
585}
586static 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 */
593static 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
601static 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
609static 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
615static 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
627static 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
641static 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 */
663static 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
676static 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}
686static DEVICE_ATTR_RW(config_test_driver);
687
688static 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
707static 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}
717static DEVICE_ATTR_RW(config_test_fs);
718
719static 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
760static void free_test_dev_info(struct kmod_test_device *test_dev)
761{
762 vfree(test_dev->info);
763 test_dev->info = NULL;
764}
765
766static 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
785static unsigned int kmod_init_test_thread_limit(void)
786{
787 return get_kmod_umh_limit();
788}
789#else
790static unsigned int kmod_init_test_thread_limit(void)
791{
792 return TEST_START_NUM_THREADS;
793}
794#endif
795
796static 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
825err_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
834static 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
855out:
856 mutex_unlock(&test_dev->config_mutex);
857 mutex_unlock(&test_dev->trigger_mutex);
858
859 return ret;
860}
861static DEVICE_ATTR_WO(reset);
862
863static 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
897static 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
921static 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
939static 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
952static 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
965static 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
976static 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
988static 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}
997static DEVICE_ATTR_RW(config_num_threads);
998
999static 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
1012static 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}
1021static DEVICE_ATTR_RW(config_test_case);
1022
1023static 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}
1032static DEVICE_ATTR_RW(test_result);
1033
1034#define TEST_KMOD_DEV_ATTR(name) &dev_attr_##name.attr
1035
1036static 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
1050ATTRIBUTE_GROUPS(test_dev);
1051
1052static 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
1063static 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
1098err_out_free_config:
1099 free_test_dev_info(test_dev);
1100 kmod_config_free(test_dev);
1101err_out_free:
1102 vfree(test_dev);
1103 test_dev = NULL;
1104err_out:
1105 return NULL;
1106}
1107
1108static 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
1120static 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
1151out:
1152 mutex_unlock(®_dev_mutex);
1153
1154 return test_dev;
1155
1156}
1157
1158static 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}
1189late_initcall(test_kmod_init);
1190
1191static
1192void 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
1208static 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}
1219module_exit(test_kmod_exit);
1220
1221MODULE_AUTHOR("Luis R. Rodriguez <mcgrof@kernel.org>");
1222MODULE_LICENSE("GPL");