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