~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

TOMOYO Linux Cross Reference
Linux/lib/test_kmod.c

Version: ~ [ linux-5.9 ] ~ [ linux-5.8.14 ] ~ [ linux-5.7.19 ] ~ [ linux-5.6.19 ] ~ [ linux-5.5.19 ] ~ [ linux-5.4.70 ] ~ [ linux-5.3.18 ] ~ [ linux-5.2.21 ] ~ [ linux-5.1.21 ] ~ [ linux-5.0.21 ] ~ [ linux-4.20.17 ] ~ [ linux-4.19.150 ] ~ [ linux-4.18.20 ] ~ [ linux-4.17.19 ] ~ [ linux-4.16.18 ] ~ [ linux-4.15.18 ] ~ [ linux-4.14.200 ] ~ [ linux-4.13.16 ] ~ [ linux-4.12.14 ] ~ [ linux-4.11.12 ] ~ [ linux-4.10.17 ] ~ [ linux-4.9.238 ] ~ [ linux-4.8.17 ] ~ [ linux-4.7.10 ] ~ [ linux-4.6.7 ] ~ [ linux-4.5.7 ] ~ [ linux-4.4.238 ] ~ [ linux-4.3.6 ] ~ [ linux-4.2.8 ] ~ [ linux-4.1.52 ] ~ [ linux-4.0.9 ] ~ [ linux-3.19.8 ] ~ [ linux-3.18.140 ] ~ [ linux-3.17.8 ] ~ [ linux-3.16.85 ] ~ [ linux-3.15.10 ] ~ [ linux-3.14.79 ] ~ [ linux-3.13.11 ] ~ [ linux-3.12.74 ] ~ [ linux-3.11.10 ] ~ [ linux-3.10.108 ] ~ [ linux-2.6.32.71 ] ~ [ linux-2.6.0 ] ~ [ linux-2.4.37.11 ] ~ [ unix-v6-master ] ~ [ ccs-tools-1.8.5 ] ~ [ policy-sample ] ~
Architecture: ~ [ i386 ] ~ [ alpha ] ~ [ m68k ] ~ [ mips ] ~ [ ppc ] ~ [ sparc ] ~ [ sparc64 ] ~

  1 /*
  2  * kmod stress test driver
  3  *
  4  * Copyright (C) 2017 Luis R. Rodriguez <mcgrof@kernel.org>
  5  *
  6  * This program is free software; you can redistribute it and/or modify it
  7  * under the terms of the GNU General Public License as published by the Free
  8  * Software Foundation; either version 2 of the License, or at your option any
  9  * later version; or, when distributed separately from the Linux kernel or
 10  * when incorporated into other software packages, subject to the following
 11  * license:
 12  *
 13  * This program is free software; you can redistribute it and/or modify it
 14  * under the terms of copyleft-next (version 0.3.1 or later) as published
 15  * at http://copyleft-next.org/.
 16  */
 17 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 18 
 19 /*
 20  * This driver provides an interface to trigger and test the kernel's
 21  * module loader through a series of configurations and a few triggers.
 22  * To test this driver use the following script as root:
 23  *
 24  * tools/testing/selftests/kmod/kmod.sh --help
 25  */
 26 
 27 #include <linux/kernel.h>
 28 #include <linux/module.h>
 29 #include <linux/kmod.h>
 30 #include <linux/printk.h>
 31 #include <linux/kthread.h>
 32 #include <linux/sched.h>
 33 #include <linux/fs.h>
 34 #include <linux/miscdevice.h>
 35 #include <linux/vmalloc.h>
 36 #include <linux/slab.h>
 37 #include <linux/device.h>
 38 
 39 #define TEST_START_NUM_THREADS  50
 40 #define TEST_START_DRIVER       "test_module"
 41 #define TEST_START_TEST_FS      "xfs"
 42 #define TEST_START_TEST_CASE    TEST_KMOD_DRIVER
 43 
 44 
 45 static bool force_init_test = false;
 46 module_param(force_init_test, bool_enable_only, 0644);
 47 MODULE_PARM_DESC(force_init_test,
 48                  "Force kicking a test immediately after driver loads");
 49 
 50 /*
 51  * For device allocation / registration
 52  */
 53 static DEFINE_MUTEX(reg_dev_mutex);
 54 static LIST_HEAD(reg_test_devs);
 55 
 56 /*
 57  * num_test_devs actually represents the *next* ID of the next
 58  * device we will allow to create.
 59  */
 60 static int num_test_devs;
 61 
 62 /**
 63  * enum kmod_test_case - linker table test case
 64  *
 65  * If you add a  test case, please be sure to review if you need to se
 66  * @need_mod_put for your tests case.
 67  *
 68  * @TEST_KMOD_DRIVER: stress tests request_module()
 69  * @TEST_KMOD_FS_TYPE: stress tests get_fs_type()
 70  */
 71 enum kmod_test_case {
 72         __TEST_KMOD_INVALID = 0,
 73 
 74         TEST_KMOD_DRIVER,
 75         TEST_KMOD_FS_TYPE,
 76 
 77         __TEST_KMOD_MAX,
 78 };
 79 
 80 struct test_config {
 81         char *test_driver;
 82         char *test_fs;
 83         unsigned int num_threads;
 84         enum kmod_test_case test_case;
 85         int test_result;
 86 };
 87 
 88 struct kmod_test_device;
 89 
 90 /**
 91  * kmod_test_device_info - thread info
 92  *
 93  * @ret_sync: return value if request_module() is used, sync request for
 94  *      @TEST_KMOD_DRIVER
 95  * @fs_sync: return value of get_fs_type() for @TEST_KMOD_FS_TYPE
 96  * @thread_idx: thread ID
 97  * @test_dev: test device test is being performed under
 98  * @need_mod_put: Some tests (get_fs_type() is one) requires putting the module
 99  *      (module_put(fs_sync->owner)) when done, otherwise you will not be able
100  *      to unload the respective modules and re-test. We use this to keep
101  *      accounting of when we need this and to help out in case we need to
102  *      error out and deal with module_put() on error.
103  */
104 struct kmod_test_device_info {
105         int ret_sync;
106         struct file_system_type *fs_sync;
107         struct task_struct *task_sync;
108         unsigned int thread_idx;
109         struct kmod_test_device *test_dev;
110         bool need_mod_put;
111 };
112 
113 /**
114  * kmod_test_device - test device to help test kmod
115  *
116  * @dev_idx: unique ID for test device
117  * @config: configuration for the test
118  * @misc_dev: we use a misc device under the hood
119  * @dev: pointer to misc_dev's own struct device
120  * @config_mutex: protects configuration of test
121  * @trigger_mutex: the test trigger can only be fired once at a time
122  * @thread_lock: protects @done count, and the @info per each thread
123  * @done: number of threads which have completed or failed
124  * @test_is_oom: when we run out of memory, use this to halt moving forward
125  * @kthreads_done: completion used to signal when all work is done
126  * @list: needed to be part of the reg_test_devs
127  * @info: array of info for each thread
128  */
129 struct kmod_test_device {
130         int dev_idx;
131         struct test_config config;
132         struct miscdevice misc_dev;
133         struct device *dev;
134         struct mutex config_mutex;
135         struct mutex trigger_mutex;
136         struct mutex thread_mutex;
137 
138         unsigned int done;
139 
140         bool test_is_oom;
141         struct completion kthreads_done;
142         struct list_head list;
143 
144         struct kmod_test_device_info *info;
145 };
146 
147 static const char *test_case_str(enum kmod_test_case test_case)
148 {
149         switch (test_case) {
150         case TEST_KMOD_DRIVER:
151                 return "TEST_KMOD_DRIVER";
152         case TEST_KMOD_FS_TYPE:
153                 return "TEST_KMOD_FS_TYPE";
154         default:
155                 return "invalid";
156         }
157 }
158 
159 static struct miscdevice *dev_to_misc_dev(struct device *dev)
160 {
161         return dev_get_drvdata(dev);
162 }
163 
164 static struct kmod_test_device *misc_dev_to_test_dev(struct miscdevice *misc_dev)
165 {
166         return container_of(misc_dev, struct kmod_test_device, misc_dev);
167 }
168 
169 static struct kmod_test_device *dev_to_test_dev(struct device *dev)
170 {
171         struct miscdevice *misc_dev;
172 
173         misc_dev = dev_to_misc_dev(dev);
174 
175         return misc_dev_to_test_dev(misc_dev);
176 }
177 
178 /* Must run with thread_mutex held */
179 static void kmod_test_done_check(struct kmod_test_device *test_dev,
180                                  unsigned int idx)
181 {
182         struct test_config *config = &test_dev->config;
183 
184         test_dev->done++;
185         dev_dbg(test_dev->dev, "Done thread count: %u\n", test_dev->done);
186 
187         if (test_dev->done == config->num_threads) {
188                 dev_info(test_dev->dev, "Done: %u threads have all run now\n",
189                          test_dev->done);
190                 dev_info(test_dev->dev, "Last thread to run: %u\n", idx);
191                 complete(&test_dev->kthreads_done);
192         }
193 }
194 
195 static void test_kmod_put_module(struct kmod_test_device_info *info)
196 {
197         struct kmod_test_device *test_dev = info->test_dev;
198         struct test_config *config = &test_dev->config;
199 
200         if (!info->need_mod_put)
201                 return;
202 
203         switch (config->test_case) {
204         case TEST_KMOD_DRIVER:
205                 break;
206         case TEST_KMOD_FS_TYPE:
207                 if (info && info->fs_sync && info->fs_sync->owner)
208                         module_put(info->fs_sync->owner);
209                 break;
210         default:
211                 BUG();
212         }
213 
214         info->need_mod_put = true;
215 }
216 
217 static int run_request(void *data)
218 {
219         struct kmod_test_device_info *info = data;
220         struct kmod_test_device *test_dev = info->test_dev;
221         struct test_config *config = &test_dev->config;
222 
223         switch (config->test_case) {
224         case TEST_KMOD_DRIVER:
225                 info->ret_sync = request_module("%s", config->test_driver);
226                 break;
227         case TEST_KMOD_FS_TYPE:
228                 info->fs_sync = get_fs_type(config->test_fs);
229                 info->need_mod_put = true;
230                 break;
231         default:
232                 /* __trigger_config_run() already checked for test sanity */
233                 BUG();
234                 return -EINVAL;
235         }
236 
237         dev_dbg(test_dev->dev, "Ran thread %u\n", info->thread_idx);
238 
239         test_kmod_put_module(info);
240 
241         mutex_lock(&test_dev->thread_mutex);
242         info->task_sync = NULL;
243         kmod_test_done_check(test_dev, info->thread_idx);
244         mutex_unlock(&test_dev->thread_mutex);
245 
246         return 0;
247 }
248 
249 static int tally_work_test(struct kmod_test_device_info *info)
250 {
251         struct kmod_test_device *test_dev = info->test_dev;
252         struct test_config *config = &test_dev->config;
253         int err_ret = 0;
254 
255         switch (config->test_case) {
256         case TEST_KMOD_DRIVER:
257                 /*
258                  * Only capture errors, if one is found that's
259                  * enough, for now.
260                  */
261                 if (info->ret_sync != 0)
262                         err_ret = info->ret_sync;
263                 dev_info(test_dev->dev,
264                          "Sync thread %d return status: %d\n",
265                          info->thread_idx, info->ret_sync);
266                 break;
267         case TEST_KMOD_FS_TYPE:
268                 /* For now we make this simple */
269                 if (!info->fs_sync)
270                         err_ret = -EINVAL;
271                 dev_info(test_dev->dev, "Sync thread %u fs: %s\n",
272                          info->thread_idx, info->fs_sync ? config->test_fs :
273                          "NULL");
274                 break;
275         default:
276                 BUG();
277         }
278 
279         return err_ret;
280 }
281 
282 /*
283  * XXX: add result option to display if all errors did not match.
284  * For now we just keep any error code if one was found.
285  *
286  * If this ran it means *all* tasks were created fine and we
287  * are now just collecting results.
288  *
289  * Only propagate errors, do not override with a subsequent sucess case.
290  */
291 static void tally_up_work(struct kmod_test_device *test_dev)
292 {
293         struct test_config *config = &test_dev->config;
294         struct kmod_test_device_info *info;
295         unsigned int idx;
296         int err_ret = 0;
297         int ret = 0;
298 
299         mutex_lock(&test_dev->thread_mutex);
300 
301         dev_info(test_dev->dev, "Results:\n");
302 
303         for (idx=0; idx < config->num_threads; idx++) {
304                 info = &test_dev->info[idx];
305                 ret = tally_work_test(info);
306                 if (ret)
307                         err_ret = ret;
308         }
309 
310         /*
311          * Note: request_module() returns 256 for a module not found even
312          * though modprobe itself returns 1.
313          */
314         config->test_result = err_ret;
315 
316         mutex_unlock(&test_dev->thread_mutex);
317 }
318 
319 static int try_one_request(struct kmod_test_device *test_dev, unsigned int idx)
320 {
321         struct kmod_test_device_info *info = &test_dev->info[idx];
322         int fail_ret = -ENOMEM;
323 
324         mutex_lock(&test_dev->thread_mutex);
325 
326         info->thread_idx = idx;
327         info->test_dev = test_dev;
328         info->task_sync = kthread_run(run_request, info, "%s-%u",
329                                       KBUILD_MODNAME, idx);
330 
331         if (!info->task_sync || IS_ERR(info->task_sync)) {
332                 test_dev->test_is_oom = true;
333                 dev_err(test_dev->dev, "Setting up thread %u failed\n", idx);
334                 info->task_sync = NULL;
335                 goto err_out;
336         } else
337                 dev_dbg(test_dev->dev, "Kicked off thread %u\n", idx);
338 
339         mutex_unlock(&test_dev->thread_mutex);
340 
341         return 0;
342 
343 err_out:
344         info->ret_sync = fail_ret;
345         mutex_unlock(&test_dev->thread_mutex);
346 
347         return fail_ret;
348 }
349 
350 static void test_dev_kmod_stop_tests(struct kmod_test_device *test_dev)
351 {
352         struct test_config *config = &test_dev->config;
353         struct kmod_test_device_info *info;
354         unsigned int i;
355 
356         dev_info(test_dev->dev, "Ending request_module() tests\n");
357 
358         mutex_lock(&test_dev->thread_mutex);
359 
360         for (i=0; i < config->num_threads; i++) {
361                 info = &test_dev->info[i];
362                 if (info->task_sync && !IS_ERR(info->task_sync)) {
363                         dev_info(test_dev->dev,
364                                  "Stopping still-running thread %i\n", i);
365                         kthread_stop(info->task_sync);
366                 }
367 
368                 /*
369                  * info->task_sync is well protected, it can only be
370                  * NULL or a pointer to a struct. If its NULL we either
371                  * never ran, or we did and we completed the work. Completed
372                  * tasks *always* put the module for us. This is a sanity
373                  * check -- just in case.
374                  */
375                 if (info->task_sync && info->need_mod_put)
376                         test_kmod_put_module(info);
377         }
378 
379         mutex_unlock(&test_dev->thread_mutex);
380 }
381 
382 /*
383  * Only wait *iff* we did not run into any errors during all of our thread
384  * set up. If run into any issues we stop threads and just bail out with
385  * an error to the trigger. This also means we don't need any tally work
386  * for any threads which fail.
387  */
388 static int try_requests(struct kmod_test_device *test_dev)
389 {
390         struct test_config *config = &test_dev->config;
391         unsigned int idx;
392         int ret;
393         bool any_error = false;
394 
395         for (idx=0; idx < config->num_threads; idx++) {
396                 if (test_dev->test_is_oom) {
397                         any_error = true;
398                         break;
399                 }
400 
401                 ret = try_one_request(test_dev, idx);
402                 if (ret) {
403                         any_error = true;
404                         break;
405                 }
406         }
407 
408         if (!any_error) {
409                 test_dev->test_is_oom = false;
410                 dev_info(test_dev->dev,
411                          "No errors were found while initializing threads\n");
412                 wait_for_completion(&test_dev->kthreads_done);
413                 tally_up_work(test_dev);
414         } else {
415                 test_dev->test_is_oom = true;
416                 dev_info(test_dev->dev,
417                          "At least one thread failed to start, stop all work\n");
418                 test_dev_kmod_stop_tests(test_dev);
419                 return -ENOMEM;
420         }
421 
422         return 0;
423 }
424 
425 static int run_test_driver(struct kmod_test_device *test_dev)
426 {
427         struct test_config *config = &test_dev->config;
428 
429         dev_info(test_dev->dev, "Test case: %s (%u)\n",
430                  test_case_str(config->test_case),
431                  config->test_case);
432         dev_info(test_dev->dev, "Test driver to load: %s\n",
433                  config->test_driver);
434         dev_info(test_dev->dev, "Number of threads to run: %u\n",
435                  config->num_threads);
436         dev_info(test_dev->dev, "Thread IDs will range from 0 - %u\n",
437                  config->num_threads - 1);
438 
439         return try_requests(test_dev);
440 }
441 
442 static int run_test_fs_type(struct kmod_test_device *test_dev)
443 {
444         struct test_config *config = &test_dev->config;
445 
446         dev_info(test_dev->dev, "Test case: %s (%u)\n",
447                  test_case_str(config->test_case),
448                  config->test_case);
449         dev_info(test_dev->dev, "Test filesystem to load: %s\n",
450                  config->test_fs);
451         dev_info(test_dev->dev, "Number of threads to run: %u\n",
452                  config->num_threads);
453         dev_info(test_dev->dev, "Thread IDs will range from 0 - %u\n",
454                  config->num_threads - 1);
455 
456         return try_requests(test_dev);
457 }
458 
459 static ssize_t config_show(struct device *dev,
460                            struct device_attribute *attr,
461                            char *buf)
462 {
463         struct kmod_test_device *test_dev = dev_to_test_dev(dev);
464         struct test_config *config = &test_dev->config;
465         int len = 0;
466 
467         mutex_lock(&test_dev->config_mutex);
468 
469         len += snprintf(buf, PAGE_SIZE,
470                         "Custom trigger configuration for: %s\n",
471                         dev_name(dev));
472 
473         len += snprintf(buf+len, PAGE_SIZE - len,
474                         "Number of threads:\t%u\n",
475                         config->num_threads);
476 
477         len += snprintf(buf+len, PAGE_SIZE - len,
478                         "Test_case:\t%s (%u)\n",
479                         test_case_str(config->test_case),
480                         config->test_case);
481 
482         if (config->test_driver)
483                 len += snprintf(buf+len, PAGE_SIZE - len,
484                                 "driver:\t%s\n",
485                                 config->test_driver);
486         else
487                 len += snprintf(buf+len, PAGE_SIZE - len,
488                                 "driver:\tEMPTY\n");
489 
490         if (config->test_fs)
491                 len += snprintf(buf+len, PAGE_SIZE - len,
492                                 "fs:\t%s\n",
493                                 config->test_fs);
494         else
495                 len += snprintf(buf+len, PAGE_SIZE - len,
496                                 "fs:\tEMPTY\n");
497 
498         mutex_unlock(&test_dev->config_mutex);
499 
500         return len;
501 }
502 static DEVICE_ATTR_RO(config);
503 
504 /*
505  * This ensures we don't allow kicking threads through if our configuration
506  * is faulty.
507  */
508 static int __trigger_config_run(struct kmod_test_device *test_dev)
509 {
510         struct test_config *config = &test_dev->config;
511 
512         test_dev->done = 0;
513 
514         switch (config->test_case) {
515         case TEST_KMOD_DRIVER:
516                 return run_test_driver(test_dev);
517         case TEST_KMOD_FS_TYPE:
518                 return run_test_fs_type(test_dev);
519         default:
520                 dev_warn(test_dev->dev,
521                          "Invalid test case requested: %u\n",
522                          config->test_case);
523                 return -EINVAL;
524         }
525 }
526 
527 static int trigger_config_run(struct kmod_test_device *test_dev)
528 {
529         struct test_config *config = &test_dev->config;
530         int ret;
531 
532         mutex_lock(&test_dev->trigger_mutex);
533         mutex_lock(&test_dev->config_mutex);
534 
535         ret = __trigger_config_run(test_dev);
536         if (ret < 0)
537                 goto out;
538         dev_info(test_dev->dev, "General test result: %d\n",
539                  config->test_result);
540 
541         /*
542          * We must return 0 after a trigger even unless something went
543          * wrong with the setup of the test. If the test setup went fine
544          * then userspace must just check the result of config->test_result.
545          * One issue with relying on the return from a call in the kernel
546          * is if the kernel returns a possitive value using this trigger
547          * will not return the value to userspace, it would be lost.
548          *
549          * By not relying on capturing the return value of tests we are using
550          * through the trigger it also us to run tests with set -e and only
551          * fail when something went wrong with the driver upon trigger
552          * requests.
553          */
554         ret = 0;
555 
556 out:
557         mutex_unlock(&test_dev->config_mutex);
558         mutex_unlock(&test_dev->trigger_mutex);
559 
560         return ret;
561 }
562 
563 static ssize_t
564 trigger_config_store(struct device *dev,
565                      struct device_attribute *attr,
566                      const char *buf, size_t count)
567 {
568         struct kmod_test_device *test_dev = dev_to_test_dev(dev);
569         int ret;
570 
571         if (test_dev->test_is_oom)
572                 return -ENOMEM;
573 
574         /* For all intents and purposes we don't care what userspace
575          * sent this trigger, we care only that we were triggered.
576          * We treat the return value only for caputuring issues with
577          * the test setup. At this point all the test variables should
578          * have been allocated so typically this should never fail.
579          */
580         ret = trigger_config_run(test_dev);
581         if (unlikely(ret < 0))
582                 goto out;
583 
584         /*
585          * Note: any return > 0 will be treated as success
586          * and the error value will not be available to userspace.
587          * Do not rely on trying to send to userspace a test value
588          * return value as possitive return errors will be lost.
589          */
590         if (WARN_ON(ret > 0))
591                 return -EINVAL;
592 
593         ret = count;
594 out:
595         return ret;
596 }
597 static DEVICE_ATTR_WO(trigger_config);
598 
599 /*
600  * XXX: move to kstrncpy() once merged.
601  *
602  * Users should use kfree_const() when freeing these.
603  */
604 static int __kstrncpy(char **dst, const char *name, size_t count, gfp_t gfp)
605 {
606         *dst = kstrndup(name, count, gfp);
607         if (!*dst)
608                 return -ENOSPC;
609         return count;
610 }
611 
612 static int config_copy_test_driver_name(struct test_config *config,
613                                     const char *name,
614                                     size_t count)
615 {
616         return __kstrncpy(&config->test_driver, name, count, GFP_KERNEL);
617 }
618 
619 
620 static int config_copy_test_fs(struct test_config *config, const char *name,
621                                size_t count)
622 {
623         return __kstrncpy(&config->test_fs, name, count, GFP_KERNEL);
624 }
625 
626 static void __kmod_config_free(struct test_config *config)
627 {
628         if (!config)
629                 return;
630 
631         kfree_const(config->test_driver);
632         config->test_driver = NULL;
633 
634         kfree_const(config->test_fs);
635         config->test_driver = NULL;
636 }
637 
638 static void kmod_config_free(struct kmod_test_device *test_dev)
639 {
640         struct test_config *config;
641 
642         if (!test_dev)
643                 return;
644 
645         config = &test_dev->config;
646 
647         mutex_lock(&test_dev->config_mutex);
648         __kmod_config_free(config);
649         mutex_unlock(&test_dev->config_mutex);
650 }
651 
652 static ssize_t config_test_driver_store(struct device *dev,
653                                         struct device_attribute *attr,
654                                         const char *buf, size_t count)
655 {
656         struct kmod_test_device *test_dev = dev_to_test_dev(dev);
657         struct test_config *config = &test_dev->config;
658         int copied;
659 
660         mutex_lock(&test_dev->config_mutex);
661 
662         kfree_const(config->test_driver);
663         config->test_driver = NULL;
664 
665         copied = config_copy_test_driver_name(config, buf, count);
666         mutex_unlock(&test_dev->config_mutex);
667 
668         return copied;
669 }
670 
671 /*
672  * As per sysfs_kf_seq_show() the buf is max PAGE_SIZE.
673  */
674 static ssize_t config_test_show_str(struct mutex *config_mutex,
675                                     char *dst,
676                                     char *src)
677 {
678         int len;
679 
680         mutex_lock(config_mutex);
681         len = snprintf(dst, PAGE_SIZE, "%s\n", src);
682         mutex_unlock(config_mutex);
683 
684         return len;
685 }
686 
687 static ssize_t config_test_driver_show(struct device *dev,
688                                         struct device_attribute *attr,
689                                         char *buf)
690 {
691         struct kmod_test_device *test_dev = dev_to_test_dev(dev);
692         struct test_config *config = &test_dev->config;
693 
694         return config_test_show_str(&test_dev->config_mutex, buf,
695                                     config->test_driver);
696 }
697 static DEVICE_ATTR(config_test_driver, 0644, config_test_driver_show,
698                    config_test_driver_store);
699 
700 static ssize_t config_test_fs_store(struct device *dev,
701                                     struct device_attribute *attr,
702                                     const char *buf, size_t count)
703 {
704         struct kmod_test_device *test_dev = dev_to_test_dev(dev);
705         struct test_config *config = &test_dev->config;
706         int copied;
707 
708         mutex_lock(&test_dev->config_mutex);
709 
710         kfree_const(config->test_fs);
711         config->test_fs = NULL;
712 
713         copied = config_copy_test_fs(config, buf, count);
714         mutex_unlock(&test_dev->config_mutex);
715 
716         return copied;
717 }
718 
719 static ssize_t config_test_fs_show(struct device *dev,
720                                    struct device_attribute *attr,
721                                    char *buf)
722 {
723         struct kmod_test_device *test_dev = dev_to_test_dev(dev);
724         struct test_config *config = &test_dev->config;
725 
726         return config_test_show_str(&test_dev->config_mutex, buf,
727                                     config->test_fs);
728 }
729 static DEVICE_ATTR(config_test_fs, 0644, config_test_fs_show,
730                    config_test_fs_store);
731 
732 static int trigger_config_run_type(struct kmod_test_device *test_dev,
733                                    enum kmod_test_case test_case,
734                                    const char *test_str)
735 {
736         int copied = 0;
737         struct test_config *config = &test_dev->config;
738 
739         mutex_lock(&test_dev->config_mutex);
740 
741         switch (test_case) {
742         case TEST_KMOD_DRIVER:
743                 kfree_const(config->test_driver);
744                 config->test_driver = NULL;
745                 copied = config_copy_test_driver_name(config, test_str,
746                                                       strlen(test_str));
747                 break;
748         case TEST_KMOD_FS_TYPE:
749                 kfree_const(config->test_fs);
750                 config->test_driver = NULL;
751                 copied = config_copy_test_fs(config, test_str,
752                                              strlen(test_str));
753                 break;
754         default:
755                 mutex_unlock(&test_dev->config_mutex);
756                 return -EINVAL;
757         }
758 
759         config->test_case = test_case;
760 
761         mutex_unlock(&test_dev->config_mutex);
762 
763         if (copied <= 0 || copied != strlen(test_str)) {
764                 test_dev->test_is_oom = true;
765                 return -ENOMEM;
766         }
767 
768         test_dev->test_is_oom = false;
769 
770         return trigger_config_run(test_dev);
771 }
772 
773 static void free_test_dev_info(struct kmod_test_device *test_dev)
774 {
775         vfree(test_dev->info);
776         test_dev->info = NULL;
777 }
778 
779 static int kmod_config_sync_info(struct kmod_test_device *test_dev)
780 {
781         struct test_config *config = &test_dev->config;
782 
783         free_test_dev_info(test_dev);
784         test_dev->info = vzalloc(config->num_threads *
785                                  sizeof(struct kmod_test_device_info));
786         if (!test_dev->info)
787                 return -ENOMEM;
788 
789         return 0;
790 }
791 
792 /*
793  * Old kernels may not have this, if you want to port this code to
794  * test it on older kernels.
795  */
796 #ifdef get_kmod_umh_limit
797 static unsigned int kmod_init_test_thread_limit(void)
798 {
799         return get_kmod_umh_limit();
800 }
801 #else
802 static unsigned int kmod_init_test_thread_limit(void)
803 {
804         return TEST_START_NUM_THREADS;
805 }
806 #endif
807 
808 static int __kmod_config_init(struct kmod_test_device *test_dev)
809 {
810         struct test_config *config = &test_dev->config;
811         int ret = -ENOMEM, copied;
812 
813         __kmod_config_free(config);
814 
815         copied = config_copy_test_driver_name(config, TEST_START_DRIVER,
816                                               strlen(TEST_START_DRIVER));
817         if (copied != strlen(TEST_START_DRIVER))
818                 goto err_out;
819 
820         copied = config_copy_test_fs(config, TEST_START_TEST_FS,
821                                      strlen(TEST_START_TEST_FS));
822         if (copied != strlen(TEST_START_TEST_FS))
823                 goto err_out;
824 
825         config->num_threads = kmod_init_test_thread_limit();
826         config->test_result = 0;
827         config->test_case = TEST_START_TEST_CASE;
828 
829         ret = kmod_config_sync_info(test_dev);
830         if (ret)
831                 goto err_out;
832 
833         test_dev->test_is_oom = false;
834 
835         return 0;
836 
837 err_out:
838         test_dev->test_is_oom = true;
839         WARN_ON(test_dev->test_is_oom);
840 
841         __kmod_config_free(config);
842 
843         return ret;
844 }
845 
846 static ssize_t reset_store(struct device *dev,
847                            struct device_attribute *attr,
848                            const char *buf, size_t count)
849 {
850         struct kmod_test_device *test_dev = dev_to_test_dev(dev);
851         int ret;
852 
853         mutex_lock(&test_dev->trigger_mutex);
854         mutex_lock(&test_dev->config_mutex);
855 
856         ret = __kmod_config_init(test_dev);
857         if (ret < 0) {
858                 ret = -ENOMEM;
859                 dev_err(dev, "could not alloc settings for config trigger: %d\n",
860                        ret);
861                 goto out;
862         }
863 
864         dev_info(dev, "reset\n");
865         ret = count;
866 
867 out:
868         mutex_unlock(&test_dev->config_mutex);
869         mutex_unlock(&test_dev->trigger_mutex);
870 
871         return ret;
872 }
873 static DEVICE_ATTR_WO(reset);
874 
875 static int test_dev_config_update_uint_sync(struct kmod_test_device *test_dev,
876                                             const char *buf, size_t size,
877                                             unsigned int *config,
878                                             int (*test_sync)(struct kmod_test_device *test_dev))
879 {
880         int ret;
881         unsigned long new;
882         unsigned int old_val;
883 
884         ret = kstrtoul(buf, 10, &new);
885         if (ret)
886                 return ret;
887 
888         if (new > UINT_MAX)
889                 return -EINVAL;
890 
891         mutex_lock(&test_dev->config_mutex);
892 
893         old_val = *config;
894         *(unsigned int *)config = new;
895 
896         ret = test_sync(test_dev);
897         if (ret) {
898                 *(unsigned int *)config = old_val;
899 
900                 ret = test_sync(test_dev);
901                 WARN_ON(ret);
902 
903                 mutex_unlock(&test_dev->config_mutex);
904                 return -EINVAL;
905         }
906 
907         mutex_unlock(&test_dev->config_mutex);
908         /* Always return full write size even if we didn't consume all */
909         return size;
910 }
911 
912 static int test_dev_config_update_uint_range(struct kmod_test_device *test_dev,
913                                              const char *buf, size_t size,
914                                              unsigned int *config,
915                                              unsigned int min,
916                                              unsigned int max)
917 {
918         int ret;
919         unsigned long new;
920 
921         ret = kstrtoul(buf, 10, &new);
922         if (ret)
923                 return ret;
924 
925         if (new < min || new > max)
926                 return -EINVAL;
927 
928         mutex_lock(&test_dev->config_mutex);
929         *config = new;
930         mutex_unlock(&test_dev->config_mutex);
931 
932         /* Always return full write size even if we didn't consume all */
933         return size;
934 }
935 
936 static int test_dev_config_update_int(struct kmod_test_device *test_dev,
937                                       const char *buf, size_t size,
938                                       int *config)
939 {
940         int ret;
941         long new;
942 
943         ret = kstrtol(buf, 10, &new);
944         if (ret)
945                 return ret;
946 
947         if (new < INT_MIN || new > INT_MAX)
948                 return -EINVAL;
949 
950         mutex_lock(&test_dev->config_mutex);
951         *config = new;
952         mutex_unlock(&test_dev->config_mutex);
953         /* Always return full write size even if we didn't consume all */
954         return size;
955 }
956 
957 static ssize_t test_dev_config_show_int(struct kmod_test_device *test_dev,
958                                         char *buf,
959                                         int config)
960 {
961         int val;
962 
963         mutex_lock(&test_dev->config_mutex);
964         val = config;
965         mutex_unlock(&test_dev->config_mutex);
966 
967         return snprintf(buf, PAGE_SIZE, "%d\n", val);
968 }
969 
970 static ssize_t test_dev_config_show_uint(struct kmod_test_device *test_dev,
971                                          char *buf,
972                                          unsigned int config)
973 {
974         unsigned int val;
975 
976         mutex_lock(&test_dev->config_mutex);
977         val = config;
978         mutex_unlock(&test_dev->config_mutex);
979 
980         return snprintf(buf, PAGE_SIZE, "%u\n", val);
981 }
982 
983 static ssize_t test_result_store(struct device *dev,
984                                  struct device_attribute *attr,
985                                  const char *buf, size_t count)
986 {
987         struct kmod_test_device *test_dev = dev_to_test_dev(dev);
988         struct test_config *config = &test_dev->config;
989 
990         return test_dev_config_update_int(test_dev, buf, count,
991                                           &config->test_result);
992 }
993 
994 static ssize_t config_num_threads_store(struct device *dev,
995                                         struct device_attribute *attr,
996                                         const char *buf, size_t count)
997 {
998         struct kmod_test_device *test_dev = dev_to_test_dev(dev);
999         struct test_config *config = &test_dev->config;
1000 
1001         return test_dev_config_update_uint_sync(test_dev, buf, count,
1002                                                 &config->num_threads,
1003                                                 kmod_config_sync_info);
1004 }
1005 
1006 static ssize_t config_num_threads_show(struct device *dev,
1007                                        struct device_attribute *attr,
1008                                        char *buf)
1009 {
1010         struct kmod_test_device *test_dev = dev_to_test_dev(dev);
1011         struct test_config *config = &test_dev->config;
1012 
1013         return test_dev_config_show_int(test_dev, buf, config->num_threads);
1014 }
1015 static DEVICE_ATTR(config_num_threads, 0644, config_num_threads_show,
1016                    config_num_threads_store);
1017 
1018 static ssize_t config_test_case_store(struct device *dev,
1019                                       struct device_attribute *attr,
1020                                       const char *buf, size_t count)
1021 {
1022         struct kmod_test_device *test_dev = dev_to_test_dev(dev);
1023         struct test_config *config = &test_dev->config;
1024 
1025         return test_dev_config_update_uint_range(test_dev, buf, count,
1026                                                  &config->test_case,
1027                                                  __TEST_KMOD_INVALID + 1,
1028                                                  __TEST_KMOD_MAX - 1);
1029 }
1030 
1031 static ssize_t config_test_case_show(struct device *dev,
1032                                      struct device_attribute *attr,
1033                                      char *buf)
1034 {
1035         struct kmod_test_device *test_dev = dev_to_test_dev(dev);
1036         struct test_config *config = &test_dev->config;
1037 
1038         return test_dev_config_show_uint(test_dev, buf, config->test_case);
1039 }
1040 static DEVICE_ATTR(config_test_case, 0644, config_test_case_show,
1041                    config_test_case_store);
1042 
1043 static ssize_t test_result_show(struct device *dev,
1044                                 struct device_attribute *attr,
1045                                 char *buf)
1046 {
1047         struct kmod_test_device *test_dev = dev_to_test_dev(dev);
1048         struct test_config *config = &test_dev->config;
1049 
1050         return test_dev_config_show_int(test_dev, buf, config->test_result);
1051 }
1052 static DEVICE_ATTR(test_result, 0644, test_result_show, test_result_store);
1053 
1054 #define TEST_KMOD_DEV_ATTR(name)                &dev_attr_##name.attr
1055 
1056 static struct attribute *test_dev_attrs[] = {
1057         TEST_KMOD_DEV_ATTR(trigger_config),
1058         TEST_KMOD_DEV_ATTR(config),
1059         TEST_KMOD_DEV_ATTR(reset),
1060 
1061         TEST_KMOD_DEV_ATTR(config_test_driver),
1062         TEST_KMOD_DEV_ATTR(config_test_fs),
1063         TEST_KMOD_DEV_ATTR(config_num_threads),
1064         TEST_KMOD_DEV_ATTR(config_test_case),
1065         TEST_KMOD_DEV_ATTR(test_result),
1066 
1067         NULL,
1068 };
1069 
1070 ATTRIBUTE_GROUPS(test_dev);
1071 
1072 static int kmod_config_init(struct kmod_test_device *test_dev)
1073 {
1074         int ret;
1075 
1076         mutex_lock(&test_dev->config_mutex);
1077         ret = __kmod_config_init(test_dev);
1078         mutex_unlock(&test_dev->config_mutex);
1079 
1080         return ret;
1081 }
1082 
1083 static struct kmod_test_device *alloc_test_dev_kmod(int idx)
1084 {
1085         int ret;
1086         struct kmod_test_device *test_dev;
1087         struct miscdevice *misc_dev;
1088 
1089         test_dev = vzalloc(sizeof(struct kmod_test_device));
1090         if (!test_dev)
1091                 goto err_out;
1092 
1093         mutex_init(&test_dev->config_mutex);
1094         mutex_init(&test_dev->trigger_mutex);
1095         mutex_init(&test_dev->thread_mutex);
1096 
1097         init_completion(&test_dev->kthreads_done);
1098 
1099         ret = kmod_config_init(test_dev);
1100         if (ret < 0) {
1101                 pr_err("Cannot alloc kmod_config_init()\n");
1102                 goto err_out_free;
1103         }
1104 
1105         test_dev->dev_idx = idx;
1106         misc_dev = &test_dev->misc_dev;
1107 
1108         misc_dev->minor = MISC_DYNAMIC_MINOR;
1109         misc_dev->name = kasprintf(GFP_KERNEL, "test_kmod%d", idx);
1110         if (!misc_dev->name) {
1111                 pr_err("Cannot alloc misc_dev->name\n");
1112                 goto err_out_free_config;
1113         }
1114         misc_dev->groups = test_dev_groups;
1115 
1116         return test_dev;
1117 
1118 err_out_free_config:
1119         free_test_dev_info(test_dev);
1120         kmod_config_free(test_dev);
1121 err_out_free:
1122         vfree(test_dev);
1123         test_dev = NULL;
1124 err_out:
1125         return NULL;
1126 }
1127 
1128 static void free_test_dev_kmod(struct kmod_test_device *test_dev)
1129 {
1130         if (test_dev) {
1131                 kfree_const(test_dev->misc_dev.name);
1132                 test_dev->misc_dev.name = NULL;
1133                 free_test_dev_info(test_dev);
1134                 kmod_config_free(test_dev);
1135                 vfree(test_dev);
1136                 test_dev = NULL;
1137         }
1138 }
1139 
1140 static struct kmod_test_device *register_test_dev_kmod(void)
1141 {
1142         struct kmod_test_device *test_dev = NULL;
1143         int ret;
1144 
1145         mutex_lock(&reg_dev_mutex);
1146 
1147         /* int should suffice for number of devices, test for wrap */
1148         if (unlikely(num_test_devs + 1) < 0) {
1149                 pr_err("reached limit of number of test devices\n");
1150                 goto out;
1151         }
1152 
1153         test_dev = alloc_test_dev_kmod(num_test_devs);
1154         if (!test_dev)
1155                 goto out;
1156 
1157         ret = misc_register(&test_dev->misc_dev);
1158         if (ret) {
1159                 pr_err("could not register misc device: %d\n", ret);
1160                 free_test_dev_kmod(test_dev);
1161                 goto out;
1162         }
1163 
1164         test_dev->dev = test_dev->misc_dev.this_device;
1165         list_add_tail(&test_dev->list, &reg_test_devs);
1166         dev_info(test_dev->dev, "interface ready\n");
1167 
1168         num_test_devs++;
1169 
1170 out:
1171         mutex_unlock(&reg_dev_mutex);
1172 
1173         return test_dev;
1174 
1175 }
1176 
1177 static int __init test_kmod_init(void)
1178 {
1179         struct kmod_test_device *test_dev;
1180         int ret;
1181 
1182         test_dev = register_test_dev_kmod();
1183         if (!test_dev) {
1184                 pr_err("Cannot add first test kmod device\n");
1185                 return -ENODEV;
1186         }
1187 
1188         /*
1189          * With some work we might be able to gracefully enable
1190          * testing with this driver built-in, for now this seems
1191          * rather risky. For those willing to try have at it,
1192          * and enable the below. Good luck! If that works, try
1193          * lowering the init level for more fun.
1194          */
1195         if (force_init_test) {
1196                 ret = trigger_config_run_type(test_dev,
1197                                               TEST_KMOD_DRIVER, "tun");
1198                 if (WARN_ON(ret))
1199                         return ret;
1200                 ret = trigger_config_run_type(test_dev,
1201                                               TEST_KMOD_FS_TYPE, "btrfs");
1202                 if (WARN_ON(ret))
1203                         return ret;
1204         }
1205 
1206         return 0;
1207 }
1208 late_initcall(test_kmod_init);
1209 
1210 static
1211 void unregister_test_dev_kmod(struct kmod_test_device *test_dev)
1212 {
1213         mutex_lock(&test_dev->trigger_mutex);
1214         mutex_lock(&test_dev->config_mutex);
1215 
1216         test_dev_kmod_stop_tests(test_dev);
1217 
1218         dev_info(test_dev->dev, "removing interface\n");
1219         misc_deregister(&test_dev->misc_dev);
1220         kfree(&test_dev->misc_dev.name);
1221 
1222         mutex_unlock(&test_dev->config_mutex);
1223         mutex_unlock(&test_dev->trigger_mutex);
1224 
1225         free_test_dev_kmod(test_dev);
1226 }
1227 
1228 static void __exit test_kmod_exit(void)
1229 {
1230         struct kmod_test_device *test_dev, *tmp;
1231 
1232         mutex_lock(&reg_dev_mutex);
1233         list_for_each_entry_safe(test_dev, tmp, &reg_test_devs, list) {
1234                 list_del(&test_dev->list);
1235                 unregister_test_dev_kmod(test_dev);
1236         }
1237         mutex_unlock(&reg_dev_mutex);
1238 }
1239 module_exit(test_kmod_exit);
1240 
1241 MODULE_AUTHOR("Luis R. Rodriguez <mcgrof@kernel.org>");
1242 MODULE_LICENSE("GPL");
1243 

~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

kernel.org | git.kernel.org | LWN.net | Project Home | Wiki (Japanese) | Wiki (English) | SVN repository | Mail admin

Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.

osdn.jp