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fe9d4f57 AD |
1 | #include <linux/kdebug.h> |
2 | #include <linux/kprobes.h> | |
9984de1a | 3 | #include <linux/export.h> |
fe9d4f57 AD |
4 | #include <linux/notifier.h> |
5 | #include <linux/rcupdate.h> | |
6 | #include <linux/vmalloc.h> | |
c166f23c | 7 | #include <linux/reboot.h> |
fe9d4f57 AD |
8 | |
9 | /* | |
10 | * Notifier list for kernel code which wants to be called | |
11 | * at shutdown. This is used to stop any idling DMA operations | |
12 | * and the like. | |
13 | */ | |
14 | BLOCKING_NOTIFIER_HEAD(reboot_notifier_list); | |
15 | ||
16 | /* | |
17 | * Notifier chain core routines. The exported routines below | |
18 | * are layered on top of these, with appropriate locking added. | |
19 | */ | |
20 | ||
21 | static int notifier_chain_register(struct notifier_block **nl, | |
22 | struct notifier_block *n) | |
23 | { | |
24 | while ((*nl) != NULL) { | |
83124657 | 25 | WARN_ONCE(((*nl) == n), "double register detected"); |
fe9d4f57 AD |
26 | if (n->priority > (*nl)->priority) |
27 | break; | |
28 | nl = &((*nl)->next); | |
29 | } | |
30 | n->next = *nl; | |
31 | rcu_assign_pointer(*nl, n); | |
32 | return 0; | |
33 | } | |
34 | ||
6546bc42 ND |
35 | static int notifier_chain_cond_register(struct notifier_block **nl, |
36 | struct notifier_block *n) | |
37 | { | |
38 | while ((*nl) != NULL) { | |
39 | if ((*nl) == n) | |
40 | return 0; | |
41 | if (n->priority > (*nl)->priority) | |
42 | break; | |
43 | nl = &((*nl)->next); | |
44 | } | |
45 | n->next = *nl; | |
46 | rcu_assign_pointer(*nl, n); | |
47 | return 0; | |
48 | } | |
49 | ||
fe9d4f57 AD |
50 | static int notifier_chain_unregister(struct notifier_block **nl, |
51 | struct notifier_block *n) | |
52 | { | |
53 | while ((*nl) != NULL) { | |
54 | if ((*nl) == n) { | |
55 | rcu_assign_pointer(*nl, n->next); | |
56 | return 0; | |
57 | } | |
58 | nl = &((*nl)->next); | |
59 | } | |
60 | return -ENOENT; | |
61 | } | |
62 | ||
63 | /** | |
64 | * notifier_call_chain - Informs the registered notifiers about an event. | |
65 | * @nl: Pointer to head of the blocking notifier chain | |
66 | * @val: Value passed unmodified to notifier function | |
67 | * @v: Pointer passed unmodified to notifier function | |
68 | * @nr_to_call: Number of notifier functions to be called. Don't care | |
69 | * value of this parameter is -1. | |
70 | * @nr_calls: Records the number of notifications sent. Don't care | |
71 | * value of this field is NULL. | |
72 | * @returns: notifier_call_chain returns the value returned by the | |
73 | * last notifier function called. | |
74 | */ | |
b40a2cb6 MH |
75 | static int notifier_call_chain(struct notifier_block **nl, |
76 | unsigned long val, void *v, | |
77 | int nr_to_call, int *nr_calls) | |
fe9d4f57 AD |
78 | { |
79 | int ret = NOTIFY_DONE; | |
80 | struct notifier_block *nb, *next_nb; | |
81 | ||
d11c563d | 82 | nb = rcu_dereference_raw(*nl); |
fe9d4f57 AD |
83 | |
84 | while (nb && nr_to_call) { | |
d11c563d | 85 | next_nb = rcu_dereference_raw(nb->next); |
1b2439db AV |
86 | |
87 | #ifdef CONFIG_DEBUG_NOTIFIERS | |
ab7476cf | 88 | if (unlikely(!func_ptr_is_kernel_text(nb->notifier_call))) { |
1b2439db AV |
89 | WARN(1, "Invalid notifier called!"); |
90 | nb = next_nb; | |
91 | continue; | |
92 | } | |
93 | #endif | |
fe9d4f57 AD |
94 | ret = nb->notifier_call(nb, val, v); |
95 | ||
96 | if (nr_calls) | |
97 | (*nr_calls)++; | |
98 | ||
3e6daded | 99 | if (ret & NOTIFY_STOP_MASK) |
fe9d4f57 AD |
100 | break; |
101 | nb = next_nb; | |
102 | nr_to_call--; | |
103 | } | |
104 | return ret; | |
105 | } | |
b40a2cb6 | 106 | NOKPROBE_SYMBOL(notifier_call_chain); |
fe9d4f57 AD |
107 | |
108 | /* | |
109 | * Atomic notifier chain routines. Registration and unregistration | |
110 | * use a spinlock, and call_chain is synchronized by RCU (no locks). | |
111 | */ | |
112 | ||
113 | /** | |
114 | * atomic_notifier_chain_register - Add notifier to an atomic notifier chain | |
115 | * @nh: Pointer to head of the atomic notifier chain | |
116 | * @n: New entry in notifier chain | |
117 | * | |
118 | * Adds a notifier to an atomic notifier chain. | |
119 | * | |
120 | * Currently always returns zero. | |
121 | */ | |
122 | int atomic_notifier_chain_register(struct atomic_notifier_head *nh, | |
123 | struct notifier_block *n) | |
124 | { | |
125 | unsigned long flags; | |
126 | int ret; | |
127 | ||
128 | spin_lock_irqsave(&nh->lock, flags); | |
129 | ret = notifier_chain_register(&nh->head, n); | |
130 | spin_unlock_irqrestore(&nh->lock, flags); | |
131 | return ret; | |
132 | } | |
133 | EXPORT_SYMBOL_GPL(atomic_notifier_chain_register); | |
134 | ||
135 | /** | |
136 | * atomic_notifier_chain_unregister - Remove notifier from an atomic notifier chain | |
137 | * @nh: Pointer to head of the atomic notifier chain | |
138 | * @n: Entry to remove from notifier chain | |
139 | * | |
140 | * Removes a notifier from an atomic notifier chain. | |
141 | * | |
142 | * Returns zero on success or %-ENOENT on failure. | |
143 | */ | |
144 | int atomic_notifier_chain_unregister(struct atomic_notifier_head *nh, | |
145 | struct notifier_block *n) | |
146 | { | |
147 | unsigned long flags; | |
148 | int ret; | |
149 | ||
150 | spin_lock_irqsave(&nh->lock, flags); | |
151 | ret = notifier_chain_unregister(&nh->head, n); | |
152 | spin_unlock_irqrestore(&nh->lock, flags); | |
153 | synchronize_rcu(); | |
154 | return ret; | |
155 | } | |
156 | EXPORT_SYMBOL_GPL(atomic_notifier_chain_unregister); | |
157 | ||
158 | /** | |
159 | * __atomic_notifier_call_chain - Call functions in an atomic notifier chain | |
160 | * @nh: Pointer to head of the atomic notifier chain | |
161 | * @val: Value passed unmodified to notifier function | |
162 | * @v: Pointer passed unmodified to notifier function | |
163 | * @nr_to_call: See the comment for notifier_call_chain. | |
164 | * @nr_calls: See the comment for notifier_call_chain. | |
165 | * | |
166 | * Calls each function in a notifier chain in turn. The functions | |
167 | * run in an atomic context, so they must not block. | |
168 | * This routine uses RCU to synchronize with changes to the chain. | |
169 | * | |
170 | * If the return value of the notifier can be and'ed | |
171 | * with %NOTIFY_STOP_MASK then atomic_notifier_call_chain() | |
172 | * will return immediately, with the return value of | |
173 | * the notifier function which halted execution. | |
174 | * Otherwise the return value is the return value | |
175 | * of the last notifier function called. | |
176 | */ | |
b40a2cb6 MH |
177 | int __atomic_notifier_call_chain(struct atomic_notifier_head *nh, |
178 | unsigned long val, void *v, | |
179 | int nr_to_call, int *nr_calls) | |
fe9d4f57 AD |
180 | { |
181 | int ret; | |
182 | ||
183 | rcu_read_lock(); | |
184 | ret = notifier_call_chain(&nh->head, val, v, nr_to_call, nr_calls); | |
185 | rcu_read_unlock(); | |
186 | return ret; | |
187 | } | |
188 | EXPORT_SYMBOL_GPL(__atomic_notifier_call_chain); | |
b40a2cb6 | 189 | NOKPROBE_SYMBOL(__atomic_notifier_call_chain); |
fe9d4f57 | 190 | |
b40a2cb6 MH |
191 | int atomic_notifier_call_chain(struct atomic_notifier_head *nh, |
192 | unsigned long val, void *v) | |
fe9d4f57 AD |
193 | { |
194 | return __atomic_notifier_call_chain(nh, val, v, -1, NULL); | |
195 | } | |
196 | EXPORT_SYMBOL_GPL(atomic_notifier_call_chain); | |
b40a2cb6 | 197 | NOKPROBE_SYMBOL(atomic_notifier_call_chain); |
fe9d4f57 AD |
198 | |
199 | /* | |
200 | * Blocking notifier chain routines. All access to the chain is | |
201 | * synchronized by an rwsem. | |
202 | */ | |
203 | ||
204 | /** | |
205 | * blocking_notifier_chain_register - Add notifier to a blocking notifier chain | |
206 | * @nh: Pointer to head of the blocking notifier chain | |
207 | * @n: New entry in notifier chain | |
208 | * | |
209 | * Adds a notifier to a blocking notifier chain. | |
210 | * Must be called in process context. | |
211 | * | |
212 | * Currently always returns zero. | |
213 | */ | |
214 | int blocking_notifier_chain_register(struct blocking_notifier_head *nh, | |
215 | struct notifier_block *n) | |
216 | { | |
217 | int ret; | |
218 | ||
219 | /* | |
220 | * This code gets used during boot-up, when task switching is | |
221 | * not yet working and interrupts must remain disabled. At | |
222 | * such times we must not call down_write(). | |
223 | */ | |
224 | if (unlikely(system_state == SYSTEM_BOOTING)) | |
225 | return notifier_chain_register(&nh->head, n); | |
226 | ||
227 | down_write(&nh->rwsem); | |
228 | ret = notifier_chain_register(&nh->head, n); | |
229 | up_write(&nh->rwsem); | |
230 | return ret; | |
231 | } | |
232 | EXPORT_SYMBOL_GPL(blocking_notifier_chain_register); | |
233 | ||
6546bc42 ND |
234 | /** |
235 | * blocking_notifier_chain_cond_register - Cond add notifier to a blocking notifier chain | |
236 | * @nh: Pointer to head of the blocking notifier chain | |
237 | * @n: New entry in notifier chain | |
238 | * | |
239 | * Adds a notifier to a blocking notifier chain, only if not already | |
240 | * present in the chain. | |
241 | * Must be called in process context. | |
242 | * | |
243 | * Currently always returns zero. | |
244 | */ | |
245 | int blocking_notifier_chain_cond_register(struct blocking_notifier_head *nh, | |
246 | struct notifier_block *n) | |
247 | { | |
248 | int ret; | |
249 | ||
250 | down_write(&nh->rwsem); | |
251 | ret = notifier_chain_cond_register(&nh->head, n); | |
252 | up_write(&nh->rwsem); | |
253 | return ret; | |
254 | } | |
255 | EXPORT_SYMBOL_GPL(blocking_notifier_chain_cond_register); | |
256 | ||
fe9d4f57 AD |
257 | /** |
258 | * blocking_notifier_chain_unregister - Remove notifier from a blocking notifier chain | |
259 | * @nh: Pointer to head of the blocking notifier chain | |
260 | * @n: Entry to remove from notifier chain | |
261 | * | |
262 | * Removes a notifier from a blocking notifier chain. | |
263 | * Must be called from process context. | |
264 | * | |
265 | * Returns zero on success or %-ENOENT on failure. | |
266 | */ | |
267 | int blocking_notifier_chain_unregister(struct blocking_notifier_head *nh, | |
268 | struct notifier_block *n) | |
269 | { | |
270 | int ret; | |
271 | ||
272 | /* | |
273 | * This code gets used during boot-up, when task switching is | |
274 | * not yet working and interrupts must remain disabled. At | |
275 | * such times we must not call down_write(). | |
276 | */ | |
277 | if (unlikely(system_state == SYSTEM_BOOTING)) | |
278 | return notifier_chain_unregister(&nh->head, n); | |
279 | ||
280 | down_write(&nh->rwsem); | |
281 | ret = notifier_chain_unregister(&nh->head, n); | |
282 | up_write(&nh->rwsem); | |
283 | return ret; | |
284 | } | |
285 | EXPORT_SYMBOL_GPL(blocking_notifier_chain_unregister); | |
286 | ||
287 | /** | |
288 | * __blocking_notifier_call_chain - Call functions in a blocking notifier chain | |
289 | * @nh: Pointer to head of the blocking notifier chain | |
290 | * @val: Value passed unmodified to notifier function | |
291 | * @v: Pointer passed unmodified to notifier function | |
292 | * @nr_to_call: See comment for notifier_call_chain. | |
293 | * @nr_calls: See comment for notifier_call_chain. | |
294 | * | |
295 | * Calls each function in a notifier chain in turn. The functions | |
296 | * run in a process context, so they are allowed to block. | |
297 | * | |
298 | * If the return value of the notifier can be and'ed | |
299 | * with %NOTIFY_STOP_MASK then blocking_notifier_call_chain() | |
300 | * will return immediately, with the return value of | |
301 | * the notifier function which halted execution. | |
302 | * Otherwise the return value is the return value | |
303 | * of the last notifier function called. | |
304 | */ | |
305 | int __blocking_notifier_call_chain(struct blocking_notifier_head *nh, | |
306 | unsigned long val, void *v, | |
307 | int nr_to_call, int *nr_calls) | |
308 | { | |
309 | int ret = NOTIFY_DONE; | |
310 | ||
311 | /* | |
312 | * We check the head outside the lock, but if this access is | |
313 | * racy then it does not matter what the result of the test | |
314 | * is, we re-check the list after having taken the lock anyway: | |
315 | */ | |
8857563b | 316 | if (rcu_access_pointer(nh->head)) { |
fe9d4f57 AD |
317 | down_read(&nh->rwsem); |
318 | ret = notifier_call_chain(&nh->head, val, v, nr_to_call, | |
319 | nr_calls); | |
320 | up_read(&nh->rwsem); | |
321 | } | |
322 | return ret; | |
323 | } | |
324 | EXPORT_SYMBOL_GPL(__blocking_notifier_call_chain); | |
325 | ||
326 | int blocking_notifier_call_chain(struct blocking_notifier_head *nh, | |
327 | unsigned long val, void *v) | |
328 | { | |
329 | return __blocking_notifier_call_chain(nh, val, v, -1, NULL); | |
330 | } | |
331 | EXPORT_SYMBOL_GPL(blocking_notifier_call_chain); | |
332 | ||
333 | /* | |
334 | * Raw notifier chain routines. There is no protection; | |
335 | * the caller must provide it. Use at your own risk! | |
336 | */ | |
337 | ||
338 | /** | |
339 | * raw_notifier_chain_register - Add notifier to a raw notifier chain | |
340 | * @nh: Pointer to head of the raw notifier chain | |
341 | * @n: New entry in notifier chain | |
342 | * | |
343 | * Adds a notifier to a raw notifier chain. | |
344 | * All locking must be provided by the caller. | |
345 | * | |
346 | * Currently always returns zero. | |
347 | */ | |
348 | int raw_notifier_chain_register(struct raw_notifier_head *nh, | |
349 | struct notifier_block *n) | |
350 | { | |
351 | return notifier_chain_register(&nh->head, n); | |
352 | } | |
353 | EXPORT_SYMBOL_GPL(raw_notifier_chain_register); | |
354 | ||
355 | /** | |
356 | * raw_notifier_chain_unregister - Remove notifier from a raw notifier chain | |
357 | * @nh: Pointer to head of the raw notifier chain | |
358 | * @n: Entry to remove from notifier chain | |
359 | * | |
360 | * Removes a notifier from a raw notifier chain. | |
361 | * All locking must be provided by the caller. | |
362 | * | |
363 | * Returns zero on success or %-ENOENT on failure. | |
364 | */ | |
365 | int raw_notifier_chain_unregister(struct raw_notifier_head *nh, | |
366 | struct notifier_block *n) | |
367 | { | |
368 | return notifier_chain_unregister(&nh->head, n); | |
369 | } | |
370 | EXPORT_SYMBOL_GPL(raw_notifier_chain_unregister); | |
371 | ||
372 | /** | |
373 | * __raw_notifier_call_chain - Call functions in a raw notifier chain | |
374 | * @nh: Pointer to head of the raw notifier chain | |
375 | * @val: Value passed unmodified to notifier function | |
376 | * @v: Pointer passed unmodified to notifier function | |
377 | * @nr_to_call: See comment for notifier_call_chain. | |
378 | * @nr_calls: See comment for notifier_call_chain | |
379 | * | |
380 | * Calls each function in a notifier chain in turn. The functions | |
381 | * run in an undefined context. | |
382 | * All locking must be provided by the caller. | |
383 | * | |
384 | * If the return value of the notifier can be and'ed | |
385 | * with %NOTIFY_STOP_MASK then raw_notifier_call_chain() | |
386 | * will return immediately, with the return value of | |
387 | * the notifier function which halted execution. | |
388 | * Otherwise the return value is the return value | |
389 | * of the last notifier function called. | |
390 | */ | |
391 | int __raw_notifier_call_chain(struct raw_notifier_head *nh, | |
392 | unsigned long val, void *v, | |
393 | int nr_to_call, int *nr_calls) | |
394 | { | |
395 | return notifier_call_chain(&nh->head, val, v, nr_to_call, nr_calls); | |
396 | } | |
397 | EXPORT_SYMBOL_GPL(__raw_notifier_call_chain); | |
398 | ||
399 | int raw_notifier_call_chain(struct raw_notifier_head *nh, | |
400 | unsigned long val, void *v) | |
401 | { | |
402 | return __raw_notifier_call_chain(nh, val, v, -1, NULL); | |
403 | } | |
404 | EXPORT_SYMBOL_GPL(raw_notifier_call_chain); | |
405 | ||
83fe27ea | 406 | #ifdef CONFIG_SRCU |
fe9d4f57 AD |
407 | /* |
408 | * SRCU notifier chain routines. Registration and unregistration | |
409 | * use a mutex, and call_chain is synchronized by SRCU (no locks). | |
410 | */ | |
411 | ||
412 | /** | |
413 | * srcu_notifier_chain_register - Add notifier to an SRCU notifier chain | |
414 | * @nh: Pointer to head of the SRCU notifier chain | |
415 | * @n: New entry in notifier chain | |
416 | * | |
417 | * Adds a notifier to an SRCU notifier chain. | |
418 | * Must be called in process context. | |
419 | * | |
420 | * Currently always returns zero. | |
421 | */ | |
422 | int srcu_notifier_chain_register(struct srcu_notifier_head *nh, | |
423 | struct notifier_block *n) | |
424 | { | |
425 | int ret; | |
426 | ||
427 | /* | |
428 | * This code gets used during boot-up, when task switching is | |
429 | * not yet working and interrupts must remain disabled. At | |
430 | * such times we must not call mutex_lock(). | |
431 | */ | |
432 | if (unlikely(system_state == SYSTEM_BOOTING)) | |
433 | return notifier_chain_register(&nh->head, n); | |
434 | ||
435 | mutex_lock(&nh->mutex); | |
436 | ret = notifier_chain_register(&nh->head, n); | |
437 | mutex_unlock(&nh->mutex); | |
438 | return ret; | |
439 | } | |
440 | EXPORT_SYMBOL_GPL(srcu_notifier_chain_register); | |
441 | ||
442 | /** | |
443 | * srcu_notifier_chain_unregister - Remove notifier from an SRCU notifier chain | |
444 | * @nh: Pointer to head of the SRCU notifier chain | |
445 | * @n: Entry to remove from notifier chain | |
446 | * | |
447 | * Removes a notifier from an SRCU notifier chain. | |
448 | * Must be called from process context. | |
449 | * | |
450 | * Returns zero on success or %-ENOENT on failure. | |
451 | */ | |
452 | int srcu_notifier_chain_unregister(struct srcu_notifier_head *nh, | |
453 | struct notifier_block *n) | |
454 | { | |
455 | int ret; | |
456 | ||
457 | /* | |
458 | * This code gets used during boot-up, when task switching is | |
459 | * not yet working and interrupts must remain disabled. At | |
460 | * such times we must not call mutex_lock(). | |
461 | */ | |
462 | if (unlikely(system_state == SYSTEM_BOOTING)) | |
463 | return notifier_chain_unregister(&nh->head, n); | |
464 | ||
465 | mutex_lock(&nh->mutex); | |
466 | ret = notifier_chain_unregister(&nh->head, n); | |
467 | mutex_unlock(&nh->mutex); | |
468 | synchronize_srcu(&nh->srcu); | |
469 | return ret; | |
470 | } | |
471 | EXPORT_SYMBOL_GPL(srcu_notifier_chain_unregister); | |
472 | ||
473 | /** | |
474 | * __srcu_notifier_call_chain - Call functions in an SRCU notifier chain | |
475 | * @nh: Pointer to head of the SRCU notifier chain | |
476 | * @val: Value passed unmodified to notifier function | |
477 | * @v: Pointer passed unmodified to notifier function | |
478 | * @nr_to_call: See comment for notifier_call_chain. | |
479 | * @nr_calls: See comment for notifier_call_chain | |
480 | * | |
481 | * Calls each function in a notifier chain in turn. The functions | |
482 | * run in a process context, so they are allowed to block. | |
483 | * | |
484 | * If the return value of the notifier can be and'ed | |
485 | * with %NOTIFY_STOP_MASK then srcu_notifier_call_chain() | |
486 | * will return immediately, with the return value of | |
487 | * the notifier function which halted execution. | |
488 | * Otherwise the return value is the return value | |
489 | * of the last notifier function called. | |
490 | */ | |
491 | int __srcu_notifier_call_chain(struct srcu_notifier_head *nh, | |
492 | unsigned long val, void *v, | |
493 | int nr_to_call, int *nr_calls) | |
494 | { | |
495 | int ret; | |
496 | int idx; | |
497 | ||
498 | idx = srcu_read_lock(&nh->srcu); | |
499 | ret = notifier_call_chain(&nh->head, val, v, nr_to_call, nr_calls); | |
500 | srcu_read_unlock(&nh->srcu, idx); | |
501 | return ret; | |
502 | } | |
503 | EXPORT_SYMBOL_GPL(__srcu_notifier_call_chain); | |
504 | ||
505 | int srcu_notifier_call_chain(struct srcu_notifier_head *nh, | |
506 | unsigned long val, void *v) | |
507 | { | |
508 | return __srcu_notifier_call_chain(nh, val, v, -1, NULL); | |
509 | } | |
510 | EXPORT_SYMBOL_GPL(srcu_notifier_call_chain); | |
511 | ||
512 | /** | |
513 | * srcu_init_notifier_head - Initialize an SRCU notifier head | |
514 | * @nh: Pointer to head of the srcu notifier chain | |
515 | * | |
516 | * Unlike other sorts of notifier heads, SRCU notifier heads require | |
517 | * dynamic initialization. Be sure to call this routine before | |
518 | * calling any of the other SRCU notifier routines for this head. | |
519 | * | |
520 | * If an SRCU notifier head is deallocated, it must first be cleaned | |
521 | * up by calling srcu_cleanup_notifier_head(). Otherwise the head's | |
522 | * per-cpu data (used by the SRCU mechanism) will leak. | |
523 | */ | |
524 | void srcu_init_notifier_head(struct srcu_notifier_head *nh) | |
525 | { | |
526 | mutex_init(&nh->mutex); | |
527 | if (init_srcu_struct(&nh->srcu) < 0) | |
528 | BUG(); | |
529 | nh->head = NULL; | |
530 | } | |
531 | EXPORT_SYMBOL_GPL(srcu_init_notifier_head); | |
532 | ||
83fe27ea PK |
533 | #endif /* CONFIG_SRCU */ |
534 | ||
fe9d4f57 AD |
535 | static ATOMIC_NOTIFIER_HEAD(die_chain); |
536 | ||
b40a2cb6 | 537 | int notrace notify_die(enum die_val val, const char *str, |
fe9d4f57 AD |
538 | struct pt_regs *regs, long err, int trap, int sig) |
539 | { | |
540 | struct die_args args = { | |
541 | .regs = regs, | |
542 | .str = str, | |
543 | .err = err, | |
544 | .trapnr = trap, | |
545 | .signr = sig, | |
546 | ||
547 | }; | |
5778077d | 548 | RCU_LOCKDEP_WARN(!rcu_is_watching(), |
e727c7d7 | 549 | "notify_die called but RCU thinks we're quiescent"); |
fe9d4f57 AD |
550 | return atomic_notifier_call_chain(&die_chain, val, &args); |
551 | } | |
b40a2cb6 | 552 | NOKPROBE_SYMBOL(notify_die); |
fe9d4f57 AD |
553 | |
554 | int register_die_notifier(struct notifier_block *nb) | |
555 | { | |
556 | vmalloc_sync_all(); | |
557 | return atomic_notifier_chain_register(&die_chain, nb); | |
558 | } | |
559 | EXPORT_SYMBOL_GPL(register_die_notifier); | |
560 | ||
561 | int unregister_die_notifier(struct notifier_block *nb) | |
562 | { | |
563 | return atomic_notifier_chain_unregister(&die_chain, nb); | |
564 | } | |
565 | EXPORT_SYMBOL_GPL(unregister_die_notifier); |