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-rw-r--r--kernel/rtmutex-tester.c436
1 files changed, 436 insertions, 0 deletions
diff --git a/kernel/rtmutex-tester.c b/kernel/rtmutex-tester.c
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+++ b/kernel/rtmutex-tester.c
@@ -0,0 +1,436 @@
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 */
9#include <linux/config.h>
10#include <linux/kthread.h>
11#include <linux/module.h>
12#include <linux/sched.h>
13#include <linux/smp_lock.h>
14#include <linux/spinlock.h>
15#include <linux/sysdev.h>
16#include <linux/timer.h>
17
18#include "rtmutex.h"
19
20#define MAX_RT_TEST_THREADS 8
21#define MAX_RT_TEST_MUTEXES 8
22
23static spinlock_t rttest_lock;
24static atomic_t rttest_event;
25
26struct test_thread_data {
27 int opcode;
28 int opdata;
29 int mutexes[MAX_RT_TEST_MUTEXES];
30 int bkl;
31 int event;
32 struct sys_device sysdev;
33};
34
35static struct test_thread_data thread_data[MAX_RT_TEST_THREADS];
36static task_t *threads[MAX_RT_TEST_THREADS];
37static struct rt_mutex mutexes[MAX_RT_TEST_MUTEXES];
38
39enum 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 */
49 RTTEST_LOCKBKL, /* 9 Lock BKL */
50 RTTEST_UNLOCKBKL, /* 10 Unlock BKL */
51 RTTEST_SIGNAL, /* 11 Signal other test thread, data = thread id */
52 RTTEST_RESETEVENT = 98, /* 98 Reset event counter */
53 RTTEST_RESET = 99, /* 99 Reset all pending operations */
54};
55
56static int handle_op(struct test_thread_data *td, int lockwakeup)
57{
58 struct sched_param schedpar;
59 int i, id, ret = -EINVAL;
60
61 switch(td->opcode) {
62
63 case RTTEST_NOP:
64 return 0;
65
66 case RTTEST_SCHEDOT:
67 schedpar.sched_priority = 0;
68 ret = sched_setscheduler(current, SCHED_NORMAL, &schedpar);
69 if (!ret)
70 set_user_nice(current, 0);
71 return ret;
72
73 case RTTEST_SCHEDRT:
74 schedpar.sched_priority = td->opdata;
75 return sched_setscheduler(current, SCHED_FIFO, &schedpar);
76
77 case RTTEST_LOCKCONT:
78 td->mutexes[td->opdata] = 1;
79 td->event = atomic_add_return(1, &rttest_event);
80 return 0;
81
82 case RTTEST_RESET:
83 for (i = 0; i < MAX_RT_TEST_MUTEXES; i++) {
84 if (td->mutexes[i] == 4) {
85 rt_mutex_unlock(&mutexes[i]);
86 td->mutexes[i] = 0;
87 }
88 }
89
90 if (!lockwakeup && td->bkl == 4) {
91 unlock_kernel();
92 td->bkl = 0;
93 }
94 return 0;
95
96 case RTTEST_RESETEVENT:
97 atomic_set(&rttest_event, 0);
98 return 0;
99
100 default:
101 if (lockwakeup)
102 return ret;
103 }
104
105 switch(td->opcode) {
106
107 case RTTEST_LOCK:
108 case RTTEST_LOCKNOWAIT:
109 id = td->opdata;
110 if (id < 0 || id >= MAX_RT_TEST_MUTEXES)
111 return ret;
112
113 td->mutexes[id] = 1;
114 td->event = atomic_add_return(1, &rttest_event);
115 rt_mutex_lock(&mutexes[id]);
116 td->event = atomic_add_return(1, &rttest_event);
117 td->mutexes[id] = 4;
118 return 0;
119
120 case RTTEST_LOCKINT:
121 case RTTEST_LOCKINTNOWAIT:
122 id = td->opdata;
123 if (id < 0 || id >= MAX_RT_TEST_MUTEXES)
124 return ret;
125
126 td->mutexes[id] = 1;
127 td->event = atomic_add_return(1, &rttest_event);
128 ret = rt_mutex_lock_interruptible(&mutexes[id], 0);
129 td->event = atomic_add_return(1, &rttest_event);
130 td->mutexes[id] = ret ? 0 : 4;
131 return ret ? -EINTR : 0;
132
133 case RTTEST_UNLOCK:
134 id = td->opdata;
135 if (id < 0 || id >= MAX_RT_TEST_MUTEXES || td->mutexes[id] != 4)
136 return ret;
137
138 td->event = atomic_add_return(1, &rttest_event);
139 rt_mutex_unlock(&mutexes[id]);
140 td->event = atomic_add_return(1, &rttest_event);
141 td->mutexes[id] = 0;
142 return 0;
143
144 case RTTEST_LOCKBKL:
145 if (td->bkl)
146 return 0;
147 td->bkl = 1;
148 lock_kernel();
149 td->bkl = 4;
150 return 0;
151
152 case RTTEST_UNLOCKBKL:
153 if (td->bkl != 4)
154 break;
155 unlock_kernel();
156 td->bkl = 0;
157 return 0;
158
159 default:
160 break;
161 }
162 return ret;
163}
164
165/*
166 * Schedule replacement for rtsem_down(). Only called for threads with
167 * PF_MUTEX_TESTER set.
168 *
169 * This allows us to have finegrained control over the event flow.
170 *
171 */
172void schedule_rt_mutex_test(struct rt_mutex *mutex)
173{
174 int tid, op, dat;
175 struct test_thread_data *td;
176
177 /* We have to lookup the task */
178 for (tid = 0; tid < MAX_RT_TEST_THREADS; tid++) {
179 if (threads[tid] == current)
180 break;
181 }
182
183 BUG_ON(tid == MAX_RT_TEST_THREADS);
184
185 td = &thread_data[tid];
186
187 op = td->opcode;
188 dat = td->opdata;
189
190 switch (op) {
191 case RTTEST_LOCK:
192 case RTTEST_LOCKINT:
193 case RTTEST_LOCKNOWAIT:
194 case RTTEST_LOCKINTNOWAIT:
195 if (mutex != &mutexes[dat])
196 break;
197
198 if (td->mutexes[dat] != 1)
199 break;
200
201 td->mutexes[dat] = 2;
202 td->event = atomic_add_return(1, &rttest_event);
203 break;
204
205 case RTTEST_LOCKBKL:
206 default:
207 break;
208 }
209
210 schedule();
211
212
213 switch (op) {
214 case RTTEST_LOCK:
215 case RTTEST_LOCKINT:
216 if (mutex != &mutexes[dat])
217 return;
218
219 if (td->mutexes[dat] != 2)
220 return;
221
222 td->mutexes[dat] = 3;
223 td->event = atomic_add_return(1, &rttest_event);
224 break;
225
226 case RTTEST_LOCKNOWAIT:
227 case RTTEST_LOCKINTNOWAIT:
228 if (mutex != &mutexes[dat])
229 return;
230
231 if (td->mutexes[dat] != 2)
232 return;
233
234 td->mutexes[dat] = 1;
235 td->event = atomic_add_return(1, &rttest_event);
236 return;
237
238 case RTTEST_LOCKBKL:
239 return;
240 default:
241 return;
242 }
243
244 td->opcode = 0;
245
246 for (;;) {
247 set_current_state(TASK_INTERRUPTIBLE);
248
249 if (td->opcode > 0) {
250 int ret;
251
252 set_current_state(TASK_RUNNING);
253 ret = handle_op(td, 1);
254 set_current_state(TASK_INTERRUPTIBLE);
255 if (td->opcode == RTTEST_LOCKCONT)
256 break;
257 td->opcode = ret;
258 }
259
260 /* Wait for the next command to be executed */
261 schedule();
262 }
263
264 /* Restore previous command and data */
265 td->opcode = op;
266 td->opdata = dat;
267}
268
269static int test_func(void *data)
270{
271 struct test_thread_data *td = data;
272 int ret;
273
274 current->flags |= PF_MUTEX_TESTER;
275 allow_signal(SIGHUP);
276
277 for(;;) {
278
279 set_current_state(TASK_INTERRUPTIBLE);
280
281 if (td->opcode > 0) {
282 set_current_state(TASK_RUNNING);
283 ret = handle_op(td, 0);
284 set_current_state(TASK_INTERRUPTIBLE);
285 td->opcode = ret;
286 }
287
288 /* Wait for the next command to be executed */
289 schedule();
290
291 if (signal_pending(current))
292 flush_signals(current);
293
294 if(kthread_should_stop())
295 break;
296 }
297 return 0;
298}
299
300/**
301 * sysfs_test_command - interface for test commands
302 * @dev: thread reference
303 * @buf: command for actual step
304 * @count: length of buffer
305 *
306 * command syntax:
307 *
308 * opcode:data
309 */
310static ssize_t sysfs_test_command(struct sys_device *dev, const char *buf,
311 size_t count)
312{
313 struct test_thread_data *td;
314 char cmdbuf[32];
315 int op, dat, tid;
316
317 td = container_of(dev, struct test_thread_data, sysdev);
318 tid = td->sysdev.id;
319
320 /* strings from sysfs write are not 0 terminated! */
321 if (count >= sizeof(cmdbuf))
322 return -EINVAL;
323
324 /* strip of \n: */
325 if (buf[count-1] == '\n')
326 count--;
327 if (count < 1)
328 return -EINVAL;
329
330 memcpy(cmdbuf, buf, count);
331 cmdbuf[count] = 0;
332
333 if (sscanf(cmdbuf, "%d:%d", &op, &dat) != 2)
334 return -EINVAL;
335
336 switch (op) {
337 case RTTEST_SIGNAL:
338 send_sig(SIGHUP, threads[tid], 0);
339 break;
340
341 default:
342 if (td->opcode > 0)
343 return -EBUSY;
344 td->opdata = dat;
345 td->opcode = op;
346 wake_up_process(threads[tid]);
347 }
348
349 return count;
350}
351
352/**
353 * sysfs_test_status - sysfs interface for rt tester
354 * @dev: thread to query
355 * @buf: char buffer to be filled with thread status info
356 */
357static ssize_t sysfs_test_status(struct sys_device *dev, char *buf)
358{
359 struct test_thread_data *td;
360 char *curr = buf;
361 task_t *tsk;
362 int i;
363
364 td = container_of(dev, struct test_thread_data, sysdev);
365 tsk = threads[td->sysdev.id];
366
367 spin_lock(&rttest_lock);
368
369 curr += sprintf(curr,
370 "O: %4d, E:%8d, S: 0x%08lx, P: %4d, N: %4d, B: %p, K: %d, M:",
371 td->opcode, td->event, tsk->state,
372 (MAX_RT_PRIO - 1) - tsk->prio,
373 (MAX_RT_PRIO - 1) - tsk->normal_prio,
374 tsk->pi_blocked_on, td->bkl);
375
376 for (i = MAX_RT_TEST_MUTEXES - 1; i >=0 ; i--)
377 curr += sprintf(curr, "%d", td->mutexes[i]);
378
379 spin_unlock(&rttest_lock);
380
381 curr += sprintf(curr, ", T: %p, R: %p\n", tsk,
382 mutexes[td->sysdev.id].owner);
383
384 return curr - buf;
385}
386
387static SYSDEV_ATTR(status, 0600, sysfs_test_status, NULL);
388static SYSDEV_ATTR(command, 0600, NULL, sysfs_test_command);
389
390static struct sysdev_class rttest_sysclass = {
391 set_kset_name("rttest"),
392};
393
394static int init_test_thread(int id)
395{
396 thread_data[id].sysdev.cls = &rttest_sysclass;
397 thread_data[id].sysdev.id = id;
398
399 threads[id] = kthread_run(test_func, &thread_data[id], "rt-test-%d", id);
400 if (IS_ERR(threads[id]))
401 return PTR_ERR(threads[id]);
402
403 return sysdev_register(&thread_data[id].sysdev);
404}
405
406static int init_rttest(void)
407{
408 int ret, i;
409
410 spin_lock_init(&rttest_lock);
411
412 for (i = 0; i < MAX_RT_TEST_MUTEXES; i++)
413 rt_mutex_init(&mutexes[i]);
414
415 ret = sysdev_class_register(&rttest_sysclass);
416 if (ret)
417 return ret;
418
419 for (i = 0; i < MAX_RT_TEST_THREADS; i++) {
420 ret = init_test_thread(i);
421 if (ret)
422 break;
423 ret = sysdev_create_file(&thread_data[i].sysdev, &attr_status);
424 if (ret)
425 break;
426 ret = sysdev_create_file(&thread_data[i].sysdev, &attr_command);
427 if (ret)
428 break;
429 }
430
431 printk("Initializing RT-Tester: %s\n", ret ? "Failed" : "OK" );
432
433 return ret;
434}
435
436device_initcall(init_rttest);
generated by cgit v1.2.2 (git 2.25.0) at 2025-11-01 13:58:41 -0400