Commit | Line | Data |
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61a87122 TG |
1 | /* |
2 | * RT-Mutex-tester: scriptable tester for rt mutexes | |
3 | * | |
4 | * started by Thomas Gleixner: | |
5 | * | |
6 | * Copyright (C) 2006, Timesys Corp., Thomas Gleixner <tglx@timesys.com> | |
7 | * | |
8 | */ | |
997d3eaf | 9 | #include <linux/device.h> |
61a87122 | 10 | #include <linux/kthread.h> |
9984de1a | 11 | #include <linux/export.h> |
61a87122 | 12 | #include <linux/sched.h> |
8bd75c77 | 13 | #include <linux/sched/rt.h> |
61a87122 | 14 | #include <linux/spinlock.h> |
61a87122 | 15 | #include <linux/timer.h> |
7dfb7103 | 16 | #include <linux/freezer.h> |
8184004e | 17 | #include <linux/stat.h> |
61a87122 TG |
18 | |
19 | #include "rtmutex.h" | |
20 | ||
21 | #define MAX_RT_TEST_THREADS 8 | |
22 | #define MAX_RT_TEST_MUTEXES 8 | |
23 | ||
24 | static spinlock_t rttest_lock; | |
25 | static atomic_t rttest_event; | |
26 | ||
27 | struct test_thread_data { | |
28 | int opcode; | |
29 | int opdata; | |
30 | int mutexes[MAX_RT_TEST_MUTEXES]; | |
61a87122 | 31 | int event; |
997d3eaf | 32 | struct device dev; |
61a87122 TG |
33 | }; |
34 | ||
35 | static struct test_thread_data thread_data[MAX_RT_TEST_THREADS]; | |
36c8b586 | 36 | static struct task_struct *threads[MAX_RT_TEST_THREADS]; |
61a87122 TG |
37 | static struct rt_mutex mutexes[MAX_RT_TEST_MUTEXES]; |
38 | ||
39 | enum test_opcodes { | |
40 | RTTEST_NOP = 0, | |
41 | RTTEST_SCHEDOT, /* 1 Sched other, data = nice */ | |
42 | RTTEST_SCHEDRT, /* 2 Sched fifo, data = prio */ | |
43 | RTTEST_LOCK, /* 3 Lock uninterruptible, data = lockindex */ | |
44 | RTTEST_LOCKNOWAIT, /* 4 Lock uninterruptible no wait in wakeup, data = lockindex */ | |
45 | RTTEST_LOCKINT, /* 5 Lock interruptible, data = lockindex */ | |
46 | RTTEST_LOCKINTNOWAIT, /* 6 Lock interruptible no wait in wakeup, data = lockindex */ | |
47 | RTTEST_LOCKCONT, /* 7 Continue locking after the wakeup delay */ | |
48 | RTTEST_UNLOCK, /* 8 Unlock, data = lockindex */ | |
dbebbfbb TG |
49 | /* 9, 10 - reserved for BKL commemoration */ |
50 | RTTEST_SIGNAL = 11, /* 11 Signal other test thread, data = thread id */ | |
61a87122 TG |
51 | RTTEST_RESETEVENT = 98, /* 98 Reset event counter */ |
52 | RTTEST_RESET = 99, /* 99 Reset all pending operations */ | |
53 | }; | |
54 | ||
55 | static int handle_op(struct test_thread_data *td, int lockwakeup) | |
56 | { | |
61a87122 TG |
57 | int i, id, ret = -EINVAL; |
58 | ||
59 | switch(td->opcode) { | |
60 | ||
61 | case RTTEST_NOP: | |
62 | return 0; | |
63 | ||
61a87122 TG |
64 | case RTTEST_LOCKCONT: |
65 | td->mutexes[td->opdata] = 1; | |
66 | td->event = atomic_add_return(1, &rttest_event); | |
67 | return 0; | |
68 | ||
69 | case RTTEST_RESET: | |
70 | for (i = 0; i < MAX_RT_TEST_MUTEXES; i++) { | |
71 | if (td->mutexes[i] == 4) { | |
72 | rt_mutex_unlock(&mutexes[i]); | |
73 | td->mutexes[i] = 0; | |
74 | } | |
75 | } | |
61a87122 TG |
76 | return 0; |
77 | ||
78 | case RTTEST_RESETEVENT: | |
79 | atomic_set(&rttest_event, 0); | |
80 | return 0; | |
81 | ||
82 | default: | |
83 | if (lockwakeup) | |
84 | return ret; | |
85 | } | |
86 | ||
87 | switch(td->opcode) { | |
88 | ||
89 | case RTTEST_LOCK: | |
90 | case RTTEST_LOCKNOWAIT: | |
91 | id = td->opdata; | |
92 | if (id < 0 || id >= MAX_RT_TEST_MUTEXES) | |
93 | return ret; | |
94 | ||
95 | td->mutexes[id] = 1; | |
96 | td->event = atomic_add_return(1, &rttest_event); | |
97 | rt_mutex_lock(&mutexes[id]); | |
98 | td->event = atomic_add_return(1, &rttest_event); | |
99 | td->mutexes[id] = 4; | |
100 | return 0; | |
101 | ||
102 | case RTTEST_LOCKINT: | |
103 | case RTTEST_LOCKINTNOWAIT: | |
104 | id = td->opdata; | |
105 | if (id < 0 || id >= MAX_RT_TEST_MUTEXES) | |
106 | return ret; | |
107 | ||
108 | td->mutexes[id] = 1; | |
109 | td->event = atomic_add_return(1, &rttest_event); | |
110 | ret = rt_mutex_lock_interruptible(&mutexes[id], 0); | |
111 | td->event = atomic_add_return(1, &rttest_event); | |
112 | td->mutexes[id] = ret ? 0 : 4; | |
113 | return ret ? -EINTR : 0; | |
114 | ||
115 | case RTTEST_UNLOCK: | |
116 | id = td->opdata; | |
117 | if (id < 0 || id >= MAX_RT_TEST_MUTEXES || td->mutexes[id] != 4) | |
118 | return ret; | |
119 | ||
120 | td->event = atomic_add_return(1, &rttest_event); | |
121 | rt_mutex_unlock(&mutexes[id]); | |
122 | td->event = atomic_add_return(1, &rttest_event); | |
123 | td->mutexes[id] = 0; | |
124 | return 0; | |
125 | ||
61a87122 TG |
126 | default: |
127 | break; | |
128 | } | |
129 | return ret; | |
130 | } | |
131 | ||
132 | /* | |
133 | * Schedule replacement for rtsem_down(). Only called for threads with | |
134 | * PF_MUTEX_TESTER set. | |
135 | * | |
136 | * This allows us to have finegrained control over the event flow. | |
137 | * | |
138 | */ | |
139 | void schedule_rt_mutex_test(struct rt_mutex *mutex) | |
140 | { | |
141 | int tid, op, dat; | |
142 | struct test_thread_data *td; | |
143 | ||
144 | /* We have to lookup the task */ | |
145 | for (tid = 0; tid < MAX_RT_TEST_THREADS; tid++) { | |
146 | if (threads[tid] == current) | |
147 | break; | |
148 | } | |
149 | ||
150 | BUG_ON(tid == MAX_RT_TEST_THREADS); | |
151 | ||
152 | td = &thread_data[tid]; | |
153 | ||
154 | op = td->opcode; | |
155 | dat = td->opdata; | |
156 | ||
157 | switch (op) { | |
158 | case RTTEST_LOCK: | |
159 | case RTTEST_LOCKINT: | |
160 | case RTTEST_LOCKNOWAIT: | |
161 | case RTTEST_LOCKINTNOWAIT: | |
162 | if (mutex != &mutexes[dat]) | |
163 | break; | |
164 | ||
165 | if (td->mutexes[dat] != 1) | |
166 | break; | |
167 | ||
168 | td->mutexes[dat] = 2; | |
169 | td->event = atomic_add_return(1, &rttest_event); | |
170 | break; | |
171 | ||
61a87122 TG |
172 | default: |
173 | break; | |
174 | } | |
175 | ||
176 | schedule(); | |
177 | ||
178 | ||
179 | switch (op) { | |
180 | case RTTEST_LOCK: | |
181 | case RTTEST_LOCKINT: | |
182 | if (mutex != &mutexes[dat]) | |
183 | return; | |
184 | ||
185 | if (td->mutexes[dat] != 2) | |
186 | return; | |
187 | ||
188 | td->mutexes[dat] = 3; | |
189 | td->event = atomic_add_return(1, &rttest_event); | |
190 | break; | |
191 | ||
192 | case RTTEST_LOCKNOWAIT: | |
193 | case RTTEST_LOCKINTNOWAIT: | |
194 | if (mutex != &mutexes[dat]) | |
195 | return; | |
196 | ||
197 | if (td->mutexes[dat] != 2) | |
198 | return; | |
199 | ||
200 | td->mutexes[dat] = 1; | |
201 | td->event = atomic_add_return(1, &rttest_event); | |
202 | return; | |
203 | ||
61a87122 TG |
204 | default: |
205 | return; | |
206 | } | |
207 | ||
208 | td->opcode = 0; | |
209 | ||
210 | for (;;) { | |
211 | set_current_state(TASK_INTERRUPTIBLE); | |
212 | ||
213 | if (td->opcode > 0) { | |
214 | int ret; | |
215 | ||
216 | set_current_state(TASK_RUNNING); | |
217 | ret = handle_op(td, 1); | |
218 | set_current_state(TASK_INTERRUPTIBLE); | |
219 | if (td->opcode == RTTEST_LOCKCONT) | |
220 | break; | |
221 | td->opcode = ret; | |
222 | } | |
223 | ||
224 | /* Wait for the next command to be executed */ | |
225 | schedule(); | |
226 | } | |
227 | ||
228 | /* Restore previous command and data */ | |
229 | td->opcode = op; | |
230 | td->opdata = dat; | |
231 | } | |
232 | ||
233 | static int test_func(void *data) | |
234 | { | |
235 | struct test_thread_data *td = data; | |
236 | int ret; | |
237 | ||
238 | current->flags |= PF_MUTEX_TESTER; | |
83144186 | 239 | set_freezable(); |
61a87122 TG |
240 | allow_signal(SIGHUP); |
241 | ||
242 | for(;;) { | |
243 | ||
244 | set_current_state(TASK_INTERRUPTIBLE); | |
245 | ||
246 | if (td->opcode > 0) { | |
247 | set_current_state(TASK_RUNNING); | |
248 | ret = handle_op(td, 0); | |
249 | set_current_state(TASK_INTERRUPTIBLE); | |
250 | td->opcode = ret; | |
251 | } | |
252 | ||
253 | /* Wait for the next command to be executed */ | |
254 | schedule(); | |
60198f99 | 255 | try_to_freeze(); |
61a87122 TG |
256 | |
257 | if (signal_pending(current)) | |
258 | flush_signals(current); | |
259 | ||
260 | if(kthread_should_stop()) | |
261 | break; | |
262 | } | |
263 | return 0; | |
264 | } | |
265 | ||
266 | /** | |
267 | * sysfs_test_command - interface for test commands | |
268 | * @dev: thread reference | |
269 | * @buf: command for actual step | |
270 | * @count: length of buffer | |
271 | * | |
272 | * command syntax: | |
273 | * | |
274 | * opcode:data | |
275 | */ | |
997d3eaf | 276 | static ssize_t sysfs_test_command(struct device *dev, struct device_attribute *attr, |
4a0b2b4d | 277 | const char *buf, size_t count) |
61a87122 | 278 | { |
0bafd214 | 279 | struct sched_param schedpar; |
61a87122 TG |
280 | struct test_thread_data *td; |
281 | char cmdbuf[32]; | |
0bafd214 | 282 | int op, dat, tid, ret; |
61a87122 | 283 | |
997d3eaf KS |
284 | td = container_of(dev, struct test_thread_data, dev); |
285 | tid = td->dev.id; | |
61a87122 TG |
286 | |
287 | /* strings from sysfs write are not 0 terminated! */ | |
288 | if (count >= sizeof(cmdbuf)) | |
289 | return -EINVAL; | |
290 | ||
291 | /* strip of \n: */ | |
292 | if (buf[count-1] == '\n') | |
293 | count--; | |
294 | if (count < 1) | |
295 | return -EINVAL; | |
296 | ||
297 | memcpy(cmdbuf, buf, count); | |
298 | cmdbuf[count] = 0; | |
299 | ||
300 | if (sscanf(cmdbuf, "%d:%d", &op, &dat) != 2) | |
301 | return -EINVAL; | |
302 | ||
303 | switch (op) { | |
0bafd214 TG |
304 | case RTTEST_SCHEDOT: |
305 | schedpar.sched_priority = 0; | |
306 | ret = sched_setscheduler(threads[tid], SCHED_NORMAL, &schedpar); | |
307 | if (ret) | |
308 | return ret; | |
309 | set_user_nice(current, 0); | |
310 | break; | |
311 | ||
312 | case RTTEST_SCHEDRT: | |
313 | schedpar.sched_priority = dat; | |
314 | ret = sched_setscheduler(threads[tid], SCHED_FIFO, &schedpar); | |
315 | if (ret) | |
316 | return ret; | |
317 | break; | |
318 | ||
61a87122 TG |
319 | case RTTEST_SIGNAL: |
320 | send_sig(SIGHUP, threads[tid], 0); | |
321 | break; | |
322 | ||
323 | default: | |
324 | if (td->opcode > 0) | |
325 | return -EBUSY; | |
326 | td->opdata = dat; | |
327 | td->opcode = op; | |
328 | wake_up_process(threads[tid]); | |
329 | } | |
330 | ||
331 | return count; | |
332 | } | |
333 | ||
334 | /** | |
335 | * sysfs_test_status - sysfs interface for rt tester | |
336 | * @dev: thread to query | |
337 | * @buf: char buffer to be filled with thread status info | |
338 | */ | |
997d3eaf | 339 | static ssize_t sysfs_test_status(struct device *dev, struct device_attribute *attr, |
4a0b2b4d | 340 | char *buf) |
61a87122 TG |
341 | { |
342 | struct test_thread_data *td; | |
36c8b586 | 343 | struct task_struct *tsk; |
61a87122 | 344 | char *curr = buf; |
61a87122 TG |
345 | int i; |
346 | ||
997d3eaf KS |
347 | td = container_of(dev, struct test_thread_data, dev); |
348 | tsk = threads[td->dev.id]; | |
61a87122 TG |
349 | |
350 | spin_lock(&rttest_lock); | |
351 | ||
352 | curr += sprintf(curr, | |
ccaa8d65 | 353 | "O: %4d, E:%8d, S: 0x%08lx, P: %4d, N: %4d, B: %p, M:", |
61a87122 TG |
354 | td->opcode, td->event, tsk->state, |
355 | (MAX_RT_PRIO - 1) - tsk->prio, | |
356 | (MAX_RT_PRIO - 1) - tsk->normal_prio, | |
ccaa8d65 | 357 | tsk->pi_blocked_on); |
61a87122 TG |
358 | |
359 | for (i = MAX_RT_TEST_MUTEXES - 1; i >=0 ; i--) | |
360 | curr += sprintf(curr, "%d", td->mutexes[i]); | |
361 | ||
362 | spin_unlock(&rttest_lock); | |
363 | ||
364 | curr += sprintf(curr, ", T: %p, R: %p\n", tsk, | |
997d3eaf | 365 | mutexes[td->dev.id].owner); |
61a87122 TG |
366 | |
367 | return curr - buf; | |
368 | } | |
369 | ||
8184004e SL |
370 | static DEVICE_ATTR(status, S_IRUSR, sysfs_test_status, NULL); |
371 | static DEVICE_ATTR(command, S_IWUSR, NULL, sysfs_test_command); | |
61a87122 | 372 | |
997d3eaf | 373 | static struct bus_type rttest_subsys = { |
af5ca3f4 | 374 | .name = "rttest", |
997d3eaf | 375 | .dev_name = "rttest", |
61a87122 TG |
376 | }; |
377 | ||
378 | static int init_test_thread(int id) | |
379 | { | |
997d3eaf KS |
380 | thread_data[id].dev.bus = &rttest_subsys; |
381 | thread_data[id].dev.id = id; | |
61a87122 TG |
382 | |
383 | threads[id] = kthread_run(test_func, &thread_data[id], "rt-test-%d", id); | |
384 | if (IS_ERR(threads[id])) | |
385 | return PTR_ERR(threads[id]); | |
386 | ||
997d3eaf | 387 | return device_register(&thread_data[id].dev); |
61a87122 TG |
388 | } |
389 | ||
390 | static int init_rttest(void) | |
391 | { | |
392 | int ret, i; | |
393 | ||
394 | spin_lock_init(&rttest_lock); | |
395 | ||
396 | for (i = 0; i < MAX_RT_TEST_MUTEXES; i++) | |
397 | rt_mutex_init(&mutexes[i]); | |
398 | ||
997d3eaf | 399 | ret = subsys_system_register(&rttest_subsys, NULL); |
61a87122 TG |
400 | if (ret) |
401 | return ret; | |
402 | ||
403 | for (i = 0; i < MAX_RT_TEST_THREADS; i++) { | |
404 | ret = init_test_thread(i); | |
405 | if (ret) | |
406 | break; | |
997d3eaf | 407 | ret = device_create_file(&thread_data[i].dev, &dev_attr_status); |
61a87122 TG |
408 | if (ret) |
409 | break; | |
997d3eaf | 410 | ret = device_create_file(&thread_data[i].dev, &dev_attr_command); |
61a87122 TG |
411 | if (ret) |
412 | break; | |
413 | } | |
414 | ||
415 | printk("Initializing RT-Tester: %s\n", ret ? "Failed" : "OK" ); | |
416 | ||
417 | return ret; | |
418 | } | |
419 | ||
420 | device_initcall(init_rttest); |