1 | /* $NetBSD: sysmon_wdog.c,v 1.29 2015/12/14 01:08:47 pgoyette Exp $ */ |
2 | |
3 | /*- |
4 | * Copyright (c) 2000 Zembu Labs, Inc. |
5 | * All rights reserved. |
6 | * |
7 | * Author: Jason R. Thorpe <thorpej@zembu.com> |
8 | * |
9 | * Redistribution and use in source and binary forms, with or without |
10 | * modification, are permitted provided that the following conditions |
11 | * are met: |
12 | * 1. Redistributions of source code must retain the above copyright |
13 | * notice, this list of conditions and the following disclaimer. |
14 | * 2. Redistributions in binary form must reproduce the above copyright |
15 | * notice, this list of conditions and the following disclaimer in the |
16 | * documentation and/or other materials provided with the distribution. |
17 | * 3. All advertising materials mentioning features or use of this software |
18 | * must display the following acknowledgement: |
19 | * This product includes software developed by Zembu Labs, Inc. |
20 | * 4. Neither the name of Zembu Labs nor the names of its employees may |
21 | * be used to endorse or promote products derived from this software |
22 | * without specific prior written permission. |
23 | * |
24 | * THIS SOFTWARE IS PROVIDED BY ZEMBU LABS, INC. ``AS IS'' AND ANY EXPRESS |
25 | * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WAR- |
26 | * RANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DIS- |
27 | * CLAIMED. IN NO EVENT SHALL ZEMBU LABS BE LIABLE FOR ANY DIRECT, INDIRECT, |
28 | * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT |
29 | * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
30 | * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
31 | * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
32 | * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF |
33 | * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
34 | */ |
35 | |
36 | /* |
37 | * Watchdog timer framework for sysmon. Hardware (and software) |
38 | * watchdog timers can register themselves here to provide a |
39 | * watchdog function, which provides an abstract interface to the |
40 | * user. |
41 | */ |
42 | |
43 | #include <sys/cdefs.h> |
44 | __KERNEL_RCSID(0, "$NetBSD: sysmon_wdog.c,v 1.29 2015/12/14 01:08:47 pgoyette Exp $" ); |
45 | |
46 | #include <sys/param.h> |
47 | #include <sys/conf.h> |
48 | #include <sys/errno.h> |
49 | #include <sys/fcntl.h> |
50 | #include <sys/condvar.h> |
51 | #include <sys/mutex.h> |
52 | #include <sys/callout.h> |
53 | #include <sys/kernel.h> |
54 | #include <sys/systm.h> |
55 | #include <sys/proc.h> |
56 | #include <sys/module.h> |
57 | #include <sys/once.h> |
58 | |
59 | #include <dev/sysmon/sysmonvar.h> |
60 | |
61 | static LIST_HEAD(, sysmon_wdog) sysmon_wdog_list = |
62 | LIST_HEAD_INITIALIZER(&sysmon_wdog_list); |
63 | static int sysmon_wdog_count; |
64 | static kmutex_t sysmon_wdog_list_mtx, sysmon_wdog_mtx; |
65 | static kcondvar_t sysmon_wdog_cv; |
66 | static struct sysmon_wdog *sysmon_armed_wdog; |
67 | static callout_t sysmon_wdog_callout; |
68 | static void *sysmon_wdog_sdhook; |
69 | static void *sysmon_wdog_cphook; |
70 | |
71 | struct sysmon_wdog *sysmon_wdog_find(const char *); |
72 | void sysmon_wdog_release(struct sysmon_wdog *); |
73 | int sysmon_wdog_setmode(struct sysmon_wdog *, int, u_int); |
74 | void sysmon_wdog_ktickle(void *); |
75 | void sysmon_wdog_critpoll(void *); |
76 | void sysmon_wdog_shutdown(void *); |
77 | void sysmon_wdog_ref(struct sysmon_wdog *); |
78 | |
79 | static struct sysmon_opvec sysmon_wdog_opvec = { |
80 | sysmonopen_wdog, sysmonclose_wdog, sysmonioctl_wdog, |
81 | NULL, NULL, NULL |
82 | }; |
83 | |
84 | MODULE(MODULE_CLASS_DRIVER, sysmon_wdog, "sysmon" ); |
85 | |
86 | ONCE_DECL(once_wdog); |
87 | |
88 | static int |
89 | wdog_preinit(void) |
90 | { |
91 | |
92 | mutex_init(&sysmon_wdog_list_mtx, MUTEX_DEFAULT, IPL_NONE); |
93 | mutex_init(&sysmon_wdog_mtx, MUTEX_DEFAULT, IPL_SOFTCLOCK); |
94 | cv_init(&sysmon_wdog_cv, "wdogref" ); |
95 | callout_init(&sysmon_wdog_callout, 0); |
96 | |
97 | return 0; |
98 | } |
99 | |
100 | int |
101 | sysmon_wdog_init(void) |
102 | { |
103 | int error; |
104 | |
105 | (void)RUN_ONCE(&once_wdog, wdog_preinit); |
106 | |
107 | sysmon_wdog_sdhook = shutdownhook_establish(sysmon_wdog_shutdown, NULL); |
108 | if (sysmon_wdog_sdhook == NULL) |
109 | printf("WARNING: unable to register watchdog shutdown hook\n" ); |
110 | sysmon_wdog_cphook = critpollhook_establish(sysmon_wdog_critpoll, NULL); |
111 | if (sysmon_wdog_cphook == NULL) |
112 | printf("WARNING: unable to register watchdog critpoll hook\n" ); |
113 | |
114 | error = sysmon_attach_minor(SYSMON_MINOR_WDOG, &sysmon_wdog_opvec); |
115 | |
116 | return error; |
117 | } |
118 | |
119 | int |
120 | sysmon_wdog_fini(void) |
121 | { |
122 | int error; |
123 | |
124 | if ( ! LIST_EMPTY(&sysmon_wdog_list)) |
125 | return EBUSY; |
126 | |
127 | error = sysmon_attach_minor(SYSMON_MINOR_WDOG, NULL); |
128 | |
129 | if (error == 0) { |
130 | callout_destroy(&sysmon_wdog_callout); |
131 | critpollhook_disestablish(sysmon_wdog_cphook); |
132 | shutdownhook_disestablish(sysmon_wdog_sdhook); |
133 | cv_destroy(&sysmon_wdog_cv); |
134 | mutex_destroy(&sysmon_wdog_mtx); |
135 | mutex_destroy(&sysmon_wdog_list_mtx); |
136 | } |
137 | |
138 | return error; |
139 | } |
140 | |
141 | /* |
142 | * sysmonopen_wdog: |
143 | * |
144 | * Open the system monitor device. |
145 | */ |
146 | int |
147 | sysmonopen_wdog(dev_t dev, int flag, int mode, struct lwp *l) |
148 | { |
149 | |
150 | return 0; |
151 | } |
152 | |
153 | /* |
154 | * sysmonclose_wdog: |
155 | * |
156 | * Close the system monitor device. |
157 | */ |
158 | int |
159 | sysmonclose_wdog(dev_t dev, int flag, int mode, struct lwp *l) |
160 | { |
161 | struct sysmon_wdog *smw; |
162 | int error = 0; |
163 | |
164 | /* |
165 | * If this is the last close, and there is a watchdog |
166 | * running in UTICKLE mode, we need to disable it, |
167 | * otherwise the system will reset in short order. |
168 | * |
169 | * XXX Maybe we should just go into KTICKLE mode? |
170 | */ |
171 | mutex_enter(&sysmon_wdog_mtx); |
172 | if ((smw = sysmon_armed_wdog) != NULL) { |
173 | if ((smw->smw_mode & WDOG_MODE_MASK) == WDOG_MODE_UTICKLE) { |
174 | error = sysmon_wdog_setmode(smw, |
175 | WDOG_MODE_DISARMED, smw->smw_period); |
176 | if (error) { |
177 | printf("WARNING: UNABLE TO DISARM " |
178 | "WATCHDOG %s ON CLOSE!\n" , |
179 | smw->smw_name); |
180 | /* |
181 | * ...we will probably reboot soon. |
182 | */ |
183 | } |
184 | } |
185 | } |
186 | mutex_exit(&sysmon_wdog_mtx); |
187 | |
188 | return error; |
189 | } |
190 | |
191 | /* |
192 | * sysmonioctl_wdog: |
193 | * |
194 | * Perform a watchdog control request. |
195 | */ |
196 | int |
197 | sysmonioctl_wdog(dev_t dev, u_long cmd, void *data, int flag, struct lwp *l) |
198 | { |
199 | struct sysmon_wdog *smw; |
200 | int error = 0; |
201 | |
202 | switch (cmd) { |
203 | case WDOGIOC_GMODE: |
204 | { |
205 | struct wdog_mode *wm = (void *) data; |
206 | |
207 | wm->wm_name[sizeof(wm->wm_name) - 1] = '\0'; |
208 | smw = sysmon_wdog_find(wm->wm_name); |
209 | if (smw == NULL) { |
210 | error = ESRCH; |
211 | break; |
212 | } |
213 | |
214 | wm->wm_mode = smw->smw_mode; |
215 | wm->wm_period = smw->smw_period; |
216 | sysmon_wdog_release(smw); |
217 | break; |
218 | } |
219 | |
220 | case WDOGIOC_SMODE: |
221 | { |
222 | struct wdog_mode *wm = (void *) data; |
223 | |
224 | if ((flag & FWRITE) == 0) { |
225 | error = EPERM; |
226 | break; |
227 | } |
228 | |
229 | wm->wm_name[sizeof(wm->wm_name) - 1] = '\0'; |
230 | smw = sysmon_wdog_find(wm->wm_name); |
231 | if (smw == NULL) { |
232 | error = ESRCH; |
233 | break; |
234 | } |
235 | |
236 | if (wm->wm_mode & ~(WDOG_MODE_MASK|WDOG_FEATURE_MASK)) |
237 | error = EINVAL; |
238 | else { |
239 | mutex_enter(&sysmon_wdog_mtx); |
240 | error = sysmon_wdog_setmode(smw, wm->wm_mode, |
241 | wm->wm_period); |
242 | mutex_exit(&sysmon_wdog_mtx); |
243 | } |
244 | |
245 | sysmon_wdog_release(smw); |
246 | break; |
247 | } |
248 | |
249 | case WDOGIOC_WHICH: |
250 | { |
251 | struct wdog_mode *wm = (void *) data; |
252 | |
253 | mutex_enter(&sysmon_wdog_mtx); |
254 | if ((smw = sysmon_armed_wdog) != NULL) { |
255 | strcpy(wm->wm_name, smw->smw_name); |
256 | wm->wm_mode = smw->smw_mode; |
257 | wm->wm_period = smw->smw_period; |
258 | } else |
259 | error = ESRCH; |
260 | mutex_exit(&sysmon_wdog_mtx); |
261 | break; |
262 | } |
263 | |
264 | case WDOGIOC_TICKLE: |
265 | if ((flag & FWRITE) == 0) { |
266 | error = EPERM; |
267 | break; |
268 | } |
269 | |
270 | mutex_enter(&sysmon_wdog_mtx); |
271 | if ((smw = sysmon_armed_wdog) != NULL) { |
272 | error = (*smw->smw_tickle)(smw); |
273 | if (error == 0) |
274 | smw->smw_tickler = l->l_proc->p_pid; |
275 | } else |
276 | error = ESRCH; |
277 | mutex_exit(&sysmon_wdog_mtx); |
278 | break; |
279 | |
280 | case WDOGIOC_GTICKLER: |
281 | if ((smw = sysmon_armed_wdog) != NULL) |
282 | *(pid_t *)data = smw->smw_tickler; |
283 | else |
284 | error = ESRCH; |
285 | break; |
286 | |
287 | case WDOGIOC_GWDOGS: |
288 | { |
289 | struct wdog_conf *wc = (void *) data; |
290 | char *cp; |
291 | int i; |
292 | |
293 | mutex_enter(&sysmon_wdog_list_mtx); |
294 | if (wc->wc_names == NULL) |
295 | wc->wc_count = sysmon_wdog_count; |
296 | else { |
297 | for (i = 0, cp = wc->wc_names, |
298 | smw = LIST_FIRST(&sysmon_wdog_list); |
299 | i < sysmon_wdog_count && smw != NULL && error == 0; |
300 | i++, cp += WDOG_NAMESIZE, |
301 | smw = LIST_NEXT(smw, smw_list)) |
302 | error = copyout(smw->smw_name, cp, |
303 | strlen(smw->smw_name) + 1); |
304 | wc->wc_count = i; |
305 | } |
306 | mutex_exit(&sysmon_wdog_list_mtx); |
307 | break; |
308 | } |
309 | |
310 | default: |
311 | error = ENOTTY; |
312 | } |
313 | |
314 | return error; |
315 | } |
316 | |
317 | /* |
318 | * sysmon_wdog_register: |
319 | * |
320 | * Register a watchdog device. |
321 | */ |
322 | int |
323 | sysmon_wdog_register(struct sysmon_wdog *smw) |
324 | { |
325 | struct sysmon_wdog *lsmw; |
326 | int error = 0; |
327 | |
328 | (void)RUN_ONCE(&once_wdog, wdog_preinit); |
329 | |
330 | mutex_enter(&sysmon_wdog_list_mtx); |
331 | |
332 | LIST_FOREACH(lsmw, &sysmon_wdog_list, smw_list) { |
333 | if (strcmp(lsmw->smw_name, smw->smw_name) == 0) { |
334 | error = EEXIST; |
335 | goto out; |
336 | } |
337 | } |
338 | |
339 | smw->smw_mode = WDOG_MODE_DISARMED; |
340 | smw->smw_tickler = (pid_t) -1; |
341 | smw->smw_refcnt = 0; |
342 | sysmon_wdog_count++; |
343 | LIST_INSERT_HEAD(&sysmon_wdog_list, smw, smw_list); |
344 | |
345 | out: |
346 | mutex_exit(&sysmon_wdog_list_mtx); |
347 | return error; |
348 | } |
349 | |
350 | /* |
351 | * sysmon_wdog_unregister: |
352 | * |
353 | * Unregister a watchdog device. |
354 | */ |
355 | int |
356 | sysmon_wdog_unregister(struct sysmon_wdog *smw) |
357 | { |
358 | int rc = 0; |
359 | |
360 | mutex_enter(&sysmon_wdog_list_mtx); |
361 | while (smw->smw_refcnt > 0 && rc == 0) { |
362 | aprint_debug("%s: %d users remain\n" , smw->smw_name, |
363 | smw->smw_refcnt); |
364 | rc = cv_wait_sig(&sysmon_wdog_cv, &sysmon_wdog_list_mtx); |
365 | } |
366 | if (rc == 0) { |
367 | sysmon_wdog_count--; |
368 | LIST_REMOVE(smw, smw_list); |
369 | } |
370 | mutex_exit(&sysmon_wdog_list_mtx); |
371 | return rc; |
372 | } |
373 | |
374 | /* |
375 | * sysmon_wdog_critpoll: |
376 | * |
377 | * Perform critical operations during long polling periods |
378 | */ |
379 | void |
380 | sysmon_wdog_critpoll(void *arg) |
381 | { |
382 | struct sysmon_wdog *smw = sysmon_armed_wdog; |
383 | |
384 | if (smw == NULL) |
385 | return; |
386 | |
387 | if ((smw->smw_mode & WDOG_MODE_MASK) == WDOG_MODE_KTICKLE) { |
388 | if ((*smw->smw_tickle)(smw) != 0) { |
389 | printf("WARNING: KERNEL TICKLE OF WATCHDOG %s " |
390 | "FAILED!\n" , smw->smw_name); |
391 | } |
392 | } |
393 | } |
394 | |
395 | /* |
396 | * sysmon_wdog_find: |
397 | * |
398 | * Find a watchdog device. We increase the reference |
399 | * count on a match. |
400 | */ |
401 | struct sysmon_wdog * |
402 | sysmon_wdog_find(const char *name) |
403 | { |
404 | struct sysmon_wdog *smw; |
405 | |
406 | mutex_enter(&sysmon_wdog_list_mtx); |
407 | |
408 | LIST_FOREACH(smw, &sysmon_wdog_list, smw_list) { |
409 | if (strcmp(smw->smw_name, name) == 0) |
410 | break; |
411 | } |
412 | |
413 | if (smw != NULL) |
414 | smw->smw_refcnt++; |
415 | |
416 | mutex_exit(&sysmon_wdog_list_mtx); |
417 | return smw; |
418 | } |
419 | |
420 | /* |
421 | * sysmon_wdog_release: |
422 | * |
423 | * Release a watchdog device. |
424 | */ |
425 | void |
426 | sysmon_wdog_release(struct sysmon_wdog *smw) |
427 | { |
428 | |
429 | mutex_enter(&sysmon_wdog_list_mtx); |
430 | KASSERT(smw->smw_refcnt != 0); |
431 | smw->smw_refcnt--; |
432 | cv_signal(&sysmon_wdog_cv); |
433 | mutex_exit(&sysmon_wdog_list_mtx); |
434 | } |
435 | |
436 | void |
437 | sysmon_wdog_ref(struct sysmon_wdog *smw) |
438 | { |
439 | mutex_enter(&sysmon_wdog_list_mtx); |
440 | smw->smw_refcnt++; |
441 | mutex_exit(&sysmon_wdog_list_mtx); |
442 | } |
443 | |
444 | /* |
445 | * sysmon_wdog_setmode: |
446 | * |
447 | * Set the mode of a watchdog device. |
448 | */ |
449 | int |
450 | sysmon_wdog_setmode(struct sysmon_wdog *smw, int mode, u_int period) |
451 | { |
452 | u_int operiod = smw->smw_period; |
453 | int omode = smw->smw_mode; |
454 | int error = 0; |
455 | |
456 | smw->smw_period = period; |
457 | smw->smw_mode = mode; |
458 | |
459 | switch (mode & WDOG_MODE_MASK) { |
460 | case WDOG_MODE_DISARMED: |
461 | if (smw != sysmon_armed_wdog) { |
462 | error = EINVAL; |
463 | goto out; |
464 | } |
465 | break; |
466 | |
467 | case WDOG_MODE_KTICKLE: |
468 | case WDOG_MODE_UTICKLE: |
469 | case WDOG_MODE_ETICKLE: |
470 | if (sysmon_armed_wdog != NULL) { |
471 | error = EBUSY; |
472 | goto out; |
473 | } |
474 | break; |
475 | |
476 | default: |
477 | error = EINVAL; |
478 | goto out; |
479 | } |
480 | |
481 | error = (*smw->smw_setmode)(smw); |
482 | |
483 | out: |
484 | if (error) { |
485 | smw->smw_period = operiod; |
486 | smw->smw_mode = omode; |
487 | } else { |
488 | if ((mode & WDOG_MODE_MASK) == WDOG_MODE_DISARMED) { |
489 | sysmon_armed_wdog = NULL; |
490 | smw->smw_tickler = (pid_t) -1; |
491 | sysmon_wdog_release(smw); |
492 | if ((omode & WDOG_MODE_MASK) == WDOG_MODE_KTICKLE) |
493 | callout_stop(&sysmon_wdog_callout); |
494 | } else { |
495 | sysmon_armed_wdog = smw; |
496 | sysmon_wdog_ref(smw); |
497 | if ((mode & WDOG_MODE_MASK) == WDOG_MODE_KTICKLE) { |
498 | callout_reset(&sysmon_wdog_callout, |
499 | WDOG_PERIOD_TO_TICKS(smw->smw_period) / 2, |
500 | sysmon_wdog_ktickle, NULL); |
501 | } |
502 | } |
503 | } |
504 | return error; |
505 | } |
506 | |
507 | /* |
508 | * sysmon_wdog_ktickle: |
509 | * |
510 | * Kernel watchdog tickle routine. |
511 | */ |
512 | void |
513 | sysmon_wdog_ktickle(void *arg) |
514 | { |
515 | struct sysmon_wdog *smw; |
516 | |
517 | mutex_enter(&sysmon_wdog_mtx); |
518 | if ((smw = sysmon_armed_wdog) != NULL) { |
519 | if ((*smw->smw_tickle)(smw) != 0) { |
520 | printf("WARNING: KERNEL TICKLE OF WATCHDOG %s " |
521 | "FAILED!\n" , smw->smw_name); |
522 | /* |
523 | * ...we will probably reboot soon. |
524 | */ |
525 | } |
526 | callout_reset(&sysmon_wdog_callout, |
527 | WDOG_PERIOD_TO_TICKS(smw->smw_period) / 2, |
528 | sysmon_wdog_ktickle, NULL); |
529 | } |
530 | mutex_exit(&sysmon_wdog_mtx); |
531 | } |
532 | |
533 | /* |
534 | * sysmon_wdog_shutdown: |
535 | * |
536 | * Perform shutdown-time operations. |
537 | */ |
538 | void |
539 | sysmon_wdog_shutdown(void *arg) |
540 | { |
541 | struct sysmon_wdog *smw; |
542 | |
543 | /* |
544 | * XXX Locking here? I don't think it's necessary. |
545 | */ |
546 | |
547 | if ((smw = sysmon_armed_wdog) != NULL) { |
548 | if (sysmon_wdog_setmode(smw, WDOG_MODE_DISARMED, |
549 | smw->smw_period)) |
550 | printf("WARNING: FAILED TO SHUTDOWN WATCHDOG %s!\n" , |
551 | smw->smw_name); |
552 | } |
553 | } |
554 | static |
555 | int |
556 | sysmon_wdog_modcmd(modcmd_t cmd, void *arg) |
557 | { |
558 | int ret; |
559 | |
560 | switch (cmd) { |
561 | case MODULE_CMD_INIT: |
562 | ret = sysmon_wdog_init(); |
563 | break; |
564 | |
565 | case MODULE_CMD_FINI: |
566 | ret = sysmon_wdog_fini(); |
567 | break; |
568 | |
569 | case MODULE_CMD_STAT: |
570 | default: |
571 | ret = ENOTTY; |
572 | } |
573 | |
574 | return ret; |
575 | } |
576 | |