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457c8996 | 1 | // SPDX-License-Identifier: GPL-2.0-only |
fe9d4f57 AD |
2 | #include <linux/kdebug.h> |
3 | #include <linux/kprobes.h> | |
9984de1a | 4 | #include <linux/export.h> |
fe9d4f57 AD |
5 | #include <linux/notifier.h> |
6 | #include <linux/rcupdate.h> | |
7 | #include <linux/vmalloc.h> | |
c166f23c | 8 | #include <linux/reboot.h> |
fe9d4f57 AD |
9 | |
10 | /* | |
11 | * Notifier list for kernel code which wants to be called | |
12 | * at shutdown. This is used to stop any idling DMA operations | |
13 | * and the like. | |
14 | */ | |
15 | BLOCKING_NOTIFIER_HEAD(reboot_notifier_list); | |
16 | ||
17 | /* | |
18 | * Notifier chain core routines. The exported routines below | |
19 | * are layered on top of these, with appropriate locking added. | |
20 | */ | |
21 | ||
22 | static int notifier_chain_register(struct notifier_block **nl, | |
23 | struct notifier_block *n) | |
24 | { | |
25 | while ((*nl) != NULL) { | |
83124657 | 26 | WARN_ONCE(((*nl) == n), "double register detected"); |
fe9d4f57 AD |
27 | if (n->priority > (*nl)->priority) |
28 | break; | |
29 | nl = &((*nl)->next); | |
30 | } | |
31 | n->next = *nl; | |
32 | rcu_assign_pointer(*nl, n); | |
33 | return 0; | |
34 | } | |
35 | ||
6546bc42 ND |
36 | static int notifier_chain_cond_register(struct notifier_block **nl, |
37 | struct notifier_block *n) | |
38 | { | |
39 | while ((*nl) != NULL) { | |
40 | if ((*nl) == n) | |
41 | return 0; | |
42 | if (n->priority > (*nl)->priority) | |
43 | break; | |
44 | nl = &((*nl)->next); | |
45 | } | |
46 | n->next = *nl; | |
47 | rcu_assign_pointer(*nl, n); | |
48 | return 0; | |
49 | } | |
50 | ||
fe9d4f57 AD |
51 | static int notifier_chain_unregister(struct notifier_block **nl, |
52 | struct notifier_block *n) | |
53 | { | |
54 | while ((*nl) != NULL) { | |
55 | if ((*nl) == n) { | |
56 | rcu_assign_pointer(*nl, n->next); | |
57 | return 0; | |
58 | } | |
59 | nl = &((*nl)->next); | |
60 | } | |
61 | return -ENOENT; | |
62 | } | |
63 | ||
64 | /** | |
65 | * notifier_call_chain - Informs the registered notifiers about an event. | |
66 | * @nl: Pointer to head of the blocking notifier chain | |
67 | * @val: Value passed unmodified to notifier function | |
68 | * @v: Pointer passed unmodified to notifier function | |
69 | * @nr_to_call: Number of notifier functions to be called. Don't care | |
70 | * value of this parameter is -1. | |
71 | * @nr_calls: Records the number of notifications sent. Don't care | |
72 | * value of this field is NULL. | |
73 | * @returns: notifier_call_chain returns the value returned by the | |
74 | * last notifier function called. | |
75 | */ | |
b40a2cb6 MH |
76 | static int notifier_call_chain(struct notifier_block **nl, |
77 | unsigned long val, void *v, | |
78 | int nr_to_call, int *nr_calls) | |
fe9d4f57 AD |
79 | { |
80 | int ret = NOTIFY_DONE; | |
81 | struct notifier_block *nb, *next_nb; | |
82 | ||
d11c563d | 83 | nb = rcu_dereference_raw(*nl); |
fe9d4f57 AD |
84 | |
85 | while (nb && nr_to_call) { | |
d11c563d | 86 | next_nb = rcu_dereference_raw(nb->next); |
1b2439db AV |
87 | |
88 | #ifdef CONFIG_DEBUG_NOTIFIERS | |
ab7476cf | 89 | if (unlikely(!func_ptr_is_kernel_text(nb->notifier_call))) { |
1b2439db AV |
90 | WARN(1, "Invalid notifier called!"); |
91 | nb = next_nb; | |
92 | continue; | |
93 | } | |
94 | #endif | |
fe9d4f57 AD |
95 | ret = nb->notifier_call(nb, val, v); |
96 | ||
97 | if (nr_calls) | |
98 | (*nr_calls)++; | |
99 | ||
3e6daded | 100 | if (ret & NOTIFY_STOP_MASK) |
fe9d4f57 AD |
101 | break; |
102 | nb = next_nb; | |
103 | nr_to_call--; | |
104 | } | |
105 | return ret; | |
106 | } | |
b40a2cb6 | 107 | NOKPROBE_SYMBOL(notifier_call_chain); |
fe9d4f57 AD |
108 | |
109 | /* | |
110 | * Atomic notifier chain routines. Registration and unregistration | |
111 | * use a spinlock, and call_chain is synchronized by RCU (no locks). | |
112 | */ | |
113 | ||
114 | /** | |
115 | * atomic_notifier_chain_register - Add notifier to an atomic notifier chain | |
116 | * @nh: Pointer to head of the atomic notifier chain | |
117 | * @n: New entry in notifier chain | |
118 | * | |
119 | * Adds a notifier to an atomic notifier chain. | |
120 | * | |
121 | * Currently always returns zero. | |
122 | */ | |
123 | int atomic_notifier_chain_register(struct atomic_notifier_head *nh, | |
124 | struct notifier_block *n) | |
125 | { | |
126 | unsigned long flags; | |
127 | int ret; | |
128 | ||
129 | spin_lock_irqsave(&nh->lock, flags); | |
130 | ret = notifier_chain_register(&nh->head, n); | |
131 | spin_unlock_irqrestore(&nh->lock, flags); | |
132 | return ret; | |
133 | } | |
134 | EXPORT_SYMBOL_GPL(atomic_notifier_chain_register); | |
135 | ||
136 | /** | |
137 | * atomic_notifier_chain_unregister - Remove notifier from an atomic notifier chain | |
138 | * @nh: Pointer to head of the atomic notifier chain | |
139 | * @n: Entry to remove from notifier chain | |
140 | * | |
141 | * Removes a notifier from an atomic notifier chain. | |
142 | * | |
143 | * Returns zero on success or %-ENOENT on failure. | |
144 | */ | |
145 | int atomic_notifier_chain_unregister(struct atomic_notifier_head *nh, | |
146 | struct notifier_block *n) | |
147 | { | |
148 | unsigned long flags; | |
149 | int ret; | |
150 | ||
151 | spin_lock_irqsave(&nh->lock, flags); | |
152 | ret = notifier_chain_unregister(&nh->head, n); | |
153 | spin_unlock_irqrestore(&nh->lock, flags); | |
154 | synchronize_rcu(); | |
155 | return ret; | |
156 | } | |
157 | EXPORT_SYMBOL_GPL(atomic_notifier_chain_unregister); | |
158 | ||
159 | /** | |
160 | * __atomic_notifier_call_chain - Call functions in an atomic notifier chain | |
161 | * @nh: Pointer to head of the atomic notifier chain | |
162 | * @val: Value passed unmodified to notifier function | |
163 | * @v: Pointer passed unmodified to notifier function | |
164 | * @nr_to_call: See the comment for notifier_call_chain. | |
165 | * @nr_calls: See the comment for notifier_call_chain. | |
166 | * | |
167 | * Calls each function in a notifier chain in turn. The functions | |
168 | * run in an atomic context, so they must not block. | |
169 | * This routine uses RCU to synchronize with changes to the chain. | |
170 | * | |
171 | * If the return value of the notifier can be and'ed | |
172 | * with %NOTIFY_STOP_MASK then atomic_notifier_call_chain() | |
173 | * will return immediately, with the return value of | |
174 | * the notifier function which halted execution. | |
175 | * Otherwise the return value is the return value | |
176 | * of the last notifier function called. | |
177 | */ | |
b40a2cb6 MH |
178 | int __atomic_notifier_call_chain(struct atomic_notifier_head *nh, |
179 | unsigned long val, void *v, | |
180 | int nr_to_call, int *nr_calls) | |
fe9d4f57 AD |
181 | { |
182 | int ret; | |
183 | ||
184 | rcu_read_lock(); | |
185 | ret = notifier_call_chain(&nh->head, val, v, nr_to_call, nr_calls); | |
186 | rcu_read_unlock(); | |
187 | return ret; | |
188 | } | |
189 | EXPORT_SYMBOL_GPL(__atomic_notifier_call_chain); | |
b40a2cb6 | 190 | NOKPROBE_SYMBOL(__atomic_notifier_call_chain); |
fe9d4f57 | 191 | |
b40a2cb6 MH |
192 | int atomic_notifier_call_chain(struct atomic_notifier_head *nh, |
193 | unsigned long val, void *v) | |
fe9d4f57 AD |
194 | { |
195 | return __atomic_notifier_call_chain(nh, val, v, -1, NULL); | |
196 | } | |
197 | EXPORT_SYMBOL_GPL(atomic_notifier_call_chain); | |
b40a2cb6 | 198 | NOKPROBE_SYMBOL(atomic_notifier_call_chain); |
fe9d4f57 AD |
199 | |
200 | /* | |
201 | * Blocking notifier chain routines. All access to the chain is | |
202 | * synchronized by an rwsem. | |
203 | */ | |
204 | ||
205 | /** | |
206 | * blocking_notifier_chain_register - Add notifier to a blocking notifier chain | |
207 | * @nh: Pointer to head of the blocking notifier chain | |
208 | * @n: New entry in notifier chain | |
209 | * | |
210 | * Adds a notifier to a blocking notifier chain. | |
211 | * Must be called in process context. | |
212 | * | |
213 | * Currently always returns zero. | |
214 | */ | |
215 | int blocking_notifier_chain_register(struct blocking_notifier_head *nh, | |
216 | struct notifier_block *n) | |
217 | { | |
218 | int ret; | |
219 | ||
220 | /* | |
221 | * This code gets used during boot-up, when task switching is | |
222 | * not yet working and interrupts must remain disabled. At | |
223 | * such times we must not call down_write(). | |
224 | */ | |
225 | if (unlikely(system_state == SYSTEM_BOOTING)) | |
226 | return notifier_chain_register(&nh->head, n); | |
227 | ||
228 | down_write(&nh->rwsem); | |
229 | ret = notifier_chain_register(&nh->head, n); | |
230 | up_write(&nh->rwsem); | |
231 | return ret; | |
232 | } | |
233 | EXPORT_SYMBOL_GPL(blocking_notifier_chain_register); | |
234 | ||
6546bc42 ND |
235 | /** |
236 | * blocking_notifier_chain_cond_register - Cond add notifier to a blocking notifier chain | |
237 | * @nh: Pointer to head of the blocking notifier chain | |
238 | * @n: New entry in notifier chain | |
239 | * | |
240 | * Adds a notifier to a blocking notifier chain, only if not already | |
241 | * present in the chain. | |
242 | * Must be called in process context. | |
243 | * | |
244 | * Currently always returns zero. | |
245 | */ | |
246 | int blocking_notifier_chain_cond_register(struct blocking_notifier_head *nh, | |
247 | struct notifier_block *n) | |
248 | { | |
249 | int ret; | |
250 | ||
251 | down_write(&nh->rwsem); | |
252 | ret = notifier_chain_cond_register(&nh->head, n); | |
253 | up_write(&nh->rwsem); | |
254 | return ret; | |
255 | } | |
256 | EXPORT_SYMBOL_GPL(blocking_notifier_chain_cond_register); | |
257 | ||
fe9d4f57 AD |
258 | /** |
259 | * blocking_notifier_chain_unregister - Remove notifier from a blocking notifier chain | |
260 | * @nh: Pointer to head of the blocking notifier chain | |
261 | * @n: Entry to remove from notifier chain | |
262 | * | |
263 | * Removes a notifier from a blocking notifier chain. | |
264 | * Must be called from process context. | |
265 | * | |
266 | * Returns zero on success or %-ENOENT on failure. | |
267 | */ | |
268 | int blocking_notifier_chain_unregister(struct blocking_notifier_head *nh, | |
269 | struct notifier_block *n) | |
270 | { | |
271 | int ret; | |
272 | ||
273 | /* | |
274 | * This code gets used during boot-up, when task switching is | |
275 | * not yet working and interrupts must remain disabled. At | |
276 | * such times we must not call down_write(). | |
277 | */ | |
278 | if (unlikely(system_state == SYSTEM_BOOTING)) | |
279 | return notifier_chain_unregister(&nh->head, n); | |
280 | ||
281 | down_write(&nh->rwsem); | |
282 | ret = notifier_chain_unregister(&nh->head, n); | |
283 | up_write(&nh->rwsem); | |
284 | return ret; | |
285 | } | |
286 | EXPORT_SYMBOL_GPL(blocking_notifier_chain_unregister); | |
287 | ||
288 | /** | |
289 | * __blocking_notifier_call_chain - Call functions in a blocking notifier chain | |
290 | * @nh: Pointer to head of the blocking notifier chain | |
291 | * @val: Value passed unmodified to notifier function | |
292 | * @v: Pointer passed unmodified to notifier function | |
293 | * @nr_to_call: See comment for notifier_call_chain. | |
294 | * @nr_calls: See comment for notifier_call_chain. | |
295 | * | |
296 | * Calls each function in a notifier chain in turn. The functions | |
297 | * run in a process context, so they are allowed to block. | |
298 | * | |
299 | * If the return value of the notifier can be and'ed | |
300 | * with %NOTIFY_STOP_MASK then blocking_notifier_call_chain() | |
301 | * will return immediately, with the return value of | |
302 | * the notifier function which halted execution. | |
303 | * Otherwise the return value is the return value | |
304 | * of the last notifier function called. | |
305 | */ | |
306 | int __blocking_notifier_call_chain(struct blocking_notifier_head *nh, | |
307 | unsigned long val, void *v, | |
308 | int nr_to_call, int *nr_calls) | |
309 | { | |
310 | int ret = NOTIFY_DONE; | |
311 | ||
312 | /* | |
313 | * We check the head outside the lock, but if this access is | |
314 | * racy then it does not matter what the result of the test | |
315 | * is, we re-check the list after having taken the lock anyway: | |
316 | */ | |
8857563b | 317 | if (rcu_access_pointer(nh->head)) { |
fe9d4f57 AD |
318 | down_read(&nh->rwsem); |
319 | ret = notifier_call_chain(&nh->head, val, v, nr_to_call, | |
320 | nr_calls); | |
321 | up_read(&nh->rwsem); | |
322 | } | |
323 | return ret; | |
324 | } | |
325 | EXPORT_SYMBOL_GPL(__blocking_notifier_call_chain); | |
326 | ||
327 | int blocking_notifier_call_chain(struct blocking_notifier_head *nh, | |
328 | unsigned long val, void *v) | |
329 | { | |
330 | return __blocking_notifier_call_chain(nh, val, v, -1, NULL); | |
331 | } | |
332 | EXPORT_SYMBOL_GPL(blocking_notifier_call_chain); | |
333 | ||
334 | /* | |
335 | * Raw notifier chain routines. There is no protection; | |
336 | * the caller must provide it. Use at your own risk! | |
337 | */ | |
338 | ||
339 | /** | |
340 | * raw_notifier_chain_register - Add notifier to a raw notifier chain | |
341 | * @nh: Pointer to head of the raw notifier chain | |
342 | * @n: New entry in notifier chain | |
343 | * | |
344 | * Adds a notifier to a raw notifier chain. | |
345 | * All locking must be provided by the caller. | |
346 | * | |
347 | * Currently always returns zero. | |
348 | */ | |
349 | int raw_notifier_chain_register(struct raw_notifier_head *nh, | |
350 | struct notifier_block *n) | |
351 | { | |
352 | return notifier_chain_register(&nh->head, n); | |
353 | } | |
354 | EXPORT_SYMBOL_GPL(raw_notifier_chain_register); | |
355 | ||
356 | /** | |
357 | * raw_notifier_chain_unregister - Remove notifier from a raw notifier chain | |
358 | * @nh: Pointer to head of the raw notifier chain | |
359 | * @n: Entry to remove from notifier chain | |
360 | * | |
361 | * Removes a notifier from a raw notifier chain. | |
362 | * All locking must be provided by the caller. | |
363 | * | |
364 | * Returns zero on success or %-ENOENT on failure. | |
365 | */ | |
366 | int raw_notifier_chain_unregister(struct raw_notifier_head *nh, | |
367 | struct notifier_block *n) | |
368 | { | |
369 | return notifier_chain_unregister(&nh->head, n); | |
370 | } | |
371 | EXPORT_SYMBOL_GPL(raw_notifier_chain_unregister); | |
372 | ||
373 | /** | |
374 | * __raw_notifier_call_chain - Call functions in a raw notifier chain | |
375 | * @nh: Pointer to head of the raw notifier chain | |
376 | * @val: Value passed unmodified to notifier function | |
377 | * @v: Pointer passed unmodified to notifier function | |
378 | * @nr_to_call: See comment for notifier_call_chain. | |
379 | * @nr_calls: See comment for notifier_call_chain | |
380 | * | |
381 | * Calls each function in a notifier chain in turn. The functions | |
382 | * run in an undefined context. | |
383 | * All locking must be provided by the caller. | |
384 | * | |
385 | * If the return value of the notifier can be and'ed | |
386 | * with %NOTIFY_STOP_MASK then raw_notifier_call_chain() | |
387 | * will return immediately, with the return value of | |
388 | * the notifier function which halted execution. | |
389 | * Otherwise the return value is the return value | |
390 | * of the last notifier function called. | |
391 | */ | |
392 | int __raw_notifier_call_chain(struct raw_notifier_head *nh, | |
393 | unsigned long val, void *v, | |
394 | int nr_to_call, int *nr_calls) | |
395 | { | |
396 | return notifier_call_chain(&nh->head, val, v, nr_to_call, nr_calls); | |
397 | } | |
398 | EXPORT_SYMBOL_GPL(__raw_notifier_call_chain); | |
399 | ||
400 | int raw_notifier_call_chain(struct raw_notifier_head *nh, | |
401 | unsigned long val, void *v) | |
402 | { | |
403 | return __raw_notifier_call_chain(nh, val, v, -1, NULL); | |
404 | } | |
405 | EXPORT_SYMBOL_GPL(raw_notifier_call_chain); | |
406 | ||
83fe27ea | 407 | #ifdef CONFIG_SRCU |
fe9d4f57 AD |
408 | /* |
409 | * SRCU notifier chain routines. Registration and unregistration | |
410 | * use a mutex, and call_chain is synchronized by SRCU (no locks). | |
411 | */ | |
412 | ||
413 | /** | |
414 | * srcu_notifier_chain_register - Add notifier to an SRCU notifier chain | |
415 | * @nh: Pointer to head of the SRCU notifier chain | |
416 | * @n: New entry in notifier chain | |
417 | * | |
418 | * Adds a notifier to an SRCU notifier chain. | |
419 | * Must be called in process context. | |
420 | * | |
421 | * Currently always returns zero. | |
422 | */ | |
423 | int srcu_notifier_chain_register(struct srcu_notifier_head *nh, | |
424 | struct notifier_block *n) | |
425 | { | |
426 | int ret; | |
427 | ||
428 | /* | |
429 | * This code gets used during boot-up, when task switching is | |
430 | * not yet working and interrupts must remain disabled. At | |
431 | * such times we must not call mutex_lock(). | |
432 | */ | |
433 | if (unlikely(system_state == SYSTEM_BOOTING)) | |
434 | return notifier_chain_register(&nh->head, n); | |
435 | ||
436 | mutex_lock(&nh->mutex); | |
437 | ret = notifier_chain_register(&nh->head, n); | |
438 | mutex_unlock(&nh->mutex); | |
439 | return ret; | |
440 | } | |
441 | EXPORT_SYMBOL_GPL(srcu_notifier_chain_register); | |
442 | ||
443 | /** | |
444 | * srcu_notifier_chain_unregister - Remove notifier from an SRCU notifier chain | |
445 | * @nh: Pointer to head of the SRCU notifier chain | |
446 | * @n: Entry to remove from notifier chain | |
447 | * | |
448 | * Removes a notifier from an SRCU notifier chain. | |
449 | * Must be called from process context. | |
450 | * | |
451 | * Returns zero on success or %-ENOENT on failure. | |
452 | */ | |
453 | int srcu_notifier_chain_unregister(struct srcu_notifier_head *nh, | |
454 | struct notifier_block *n) | |
455 | { | |
456 | int ret; | |
457 | ||
458 | /* | |
459 | * This code gets used during boot-up, when task switching is | |
460 | * not yet working and interrupts must remain disabled. At | |
461 | * such times we must not call mutex_lock(). | |
462 | */ | |
463 | if (unlikely(system_state == SYSTEM_BOOTING)) | |
464 | return notifier_chain_unregister(&nh->head, n); | |
465 | ||
466 | mutex_lock(&nh->mutex); | |
467 | ret = notifier_chain_unregister(&nh->head, n); | |
468 | mutex_unlock(&nh->mutex); | |
469 | synchronize_srcu(&nh->srcu); | |
470 | return ret; | |
471 | } | |
472 | EXPORT_SYMBOL_GPL(srcu_notifier_chain_unregister); | |
473 | ||
474 | /** | |
475 | * __srcu_notifier_call_chain - Call functions in an SRCU notifier chain | |
476 | * @nh: Pointer to head of the SRCU notifier chain | |
477 | * @val: Value passed unmodified to notifier function | |
478 | * @v: Pointer passed unmodified to notifier function | |
479 | * @nr_to_call: See comment for notifier_call_chain. | |
480 | * @nr_calls: See comment for notifier_call_chain | |
481 | * | |
482 | * Calls each function in a notifier chain in turn. The functions | |
483 | * run in a process context, so they are allowed to block. | |
484 | * | |
485 | * If the return value of the notifier can be and'ed | |
486 | * with %NOTIFY_STOP_MASK then srcu_notifier_call_chain() | |
487 | * will return immediately, with the return value of | |
488 | * the notifier function which halted execution. | |
489 | * Otherwise the return value is the return value | |
490 | * of the last notifier function called. | |
491 | */ | |
492 | int __srcu_notifier_call_chain(struct srcu_notifier_head *nh, | |
493 | unsigned long val, void *v, | |
494 | int nr_to_call, int *nr_calls) | |
495 | { | |
496 | int ret; | |
497 | int idx; | |
498 | ||
499 | idx = srcu_read_lock(&nh->srcu); | |
500 | ret = notifier_call_chain(&nh->head, val, v, nr_to_call, nr_calls); | |
501 | srcu_read_unlock(&nh->srcu, idx); | |
502 | return ret; | |
503 | } | |
504 | EXPORT_SYMBOL_GPL(__srcu_notifier_call_chain); | |
505 | ||
506 | int srcu_notifier_call_chain(struct srcu_notifier_head *nh, | |
507 | unsigned long val, void *v) | |
508 | { | |
509 | return __srcu_notifier_call_chain(nh, val, v, -1, NULL); | |
510 | } | |
511 | EXPORT_SYMBOL_GPL(srcu_notifier_call_chain); | |
512 | ||
513 | /** | |
514 | * srcu_init_notifier_head - Initialize an SRCU notifier head | |
515 | * @nh: Pointer to head of the srcu notifier chain | |
516 | * | |
517 | * Unlike other sorts of notifier heads, SRCU notifier heads require | |
518 | * dynamic initialization. Be sure to call this routine before | |
519 | * calling any of the other SRCU notifier routines for this head. | |
520 | * | |
521 | * If an SRCU notifier head is deallocated, it must first be cleaned | |
522 | * up by calling srcu_cleanup_notifier_head(). Otherwise the head's | |
523 | * per-cpu data (used by the SRCU mechanism) will leak. | |
524 | */ | |
525 | void srcu_init_notifier_head(struct srcu_notifier_head *nh) | |
526 | { | |
527 | mutex_init(&nh->mutex); | |
528 | if (init_srcu_struct(&nh->srcu) < 0) | |
529 | BUG(); | |
530 | nh->head = NULL; | |
531 | } | |
532 | EXPORT_SYMBOL_GPL(srcu_init_notifier_head); | |
533 | ||
83fe27ea PK |
534 | #endif /* CONFIG_SRCU */ |
535 | ||
fe9d4f57 AD |
536 | static ATOMIC_NOTIFIER_HEAD(die_chain); |
537 | ||
b40a2cb6 | 538 | int notrace notify_die(enum die_val val, const char *str, |
fe9d4f57 AD |
539 | struct pt_regs *regs, long err, int trap, int sig) |
540 | { | |
541 | struct die_args args = { | |
542 | .regs = regs, | |
543 | .str = str, | |
544 | .err = err, | |
545 | .trapnr = trap, | |
546 | .signr = sig, | |
547 | ||
548 | }; | |
5778077d | 549 | RCU_LOCKDEP_WARN(!rcu_is_watching(), |
e727c7d7 | 550 | "notify_die called but RCU thinks we're quiescent"); |
fe9d4f57 AD |
551 | return atomic_notifier_call_chain(&die_chain, val, &args); |
552 | } | |
b40a2cb6 | 553 | NOKPROBE_SYMBOL(notify_die); |
fe9d4f57 AD |
554 | |
555 | int register_die_notifier(struct notifier_block *nb) | |
556 | { | |
557 | vmalloc_sync_all(); | |
558 | return atomic_notifier_chain_register(&die_chain, nb); | |
559 | } | |
560 | EXPORT_SYMBOL_GPL(register_die_notifier); | |
561 | ||
562 | int unregister_die_notifier(struct notifier_block *nb) | |
563 | { | |
564 | return atomic_notifier_chain_unregister(&die_chain, nb); | |
565 | } | |
566 | EXPORT_SYMBOL_GPL(unregister_die_notifier); |