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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) { | |
fed361ce XN |
26 | if (unlikely((*nl) == n)) { |
27 | WARN(1, "double register detected"); | |
28 | return 0; | |
29 | } | |
fe9d4f57 AD |
30 | if (n->priority > (*nl)->priority) |
31 | break; | |
32 | nl = &((*nl)->next); | |
33 | } | |
34 | n->next = *nl; | |
35 | rcu_assign_pointer(*nl, n); | |
36 | return 0; | |
37 | } | |
38 | ||
6546bc42 ND |
39 | static int notifier_chain_cond_register(struct notifier_block **nl, |
40 | struct notifier_block *n) | |
41 | { | |
42 | while ((*nl) != NULL) { | |
43 | if ((*nl) == n) | |
44 | return 0; | |
45 | if (n->priority > (*nl)->priority) | |
46 | break; | |
47 | nl = &((*nl)->next); | |
48 | } | |
49 | n->next = *nl; | |
50 | rcu_assign_pointer(*nl, n); | |
51 | return 0; | |
52 | } | |
53 | ||
fe9d4f57 AD |
54 | static int notifier_chain_unregister(struct notifier_block **nl, |
55 | struct notifier_block *n) | |
56 | { | |
57 | while ((*nl) != NULL) { | |
58 | if ((*nl) == n) { | |
59 | rcu_assign_pointer(*nl, n->next); | |
60 | return 0; | |
61 | } | |
62 | nl = &((*nl)->next); | |
63 | } | |
64 | return -ENOENT; | |
65 | } | |
66 | ||
67 | /** | |
68 | * notifier_call_chain - Informs the registered notifiers about an event. | |
69 | * @nl: Pointer to head of the blocking notifier chain | |
70 | * @val: Value passed unmodified to notifier function | |
71 | * @v: Pointer passed unmodified to notifier function | |
72 | * @nr_to_call: Number of notifier functions to be called. Don't care | |
73 | * value of this parameter is -1. | |
74 | * @nr_calls: Records the number of notifications sent. Don't care | |
75 | * value of this field is NULL. | |
76 | * @returns: notifier_call_chain returns the value returned by the | |
77 | * last notifier function called. | |
78 | */ | |
b40a2cb6 MH |
79 | static int notifier_call_chain(struct notifier_block **nl, |
80 | unsigned long val, void *v, | |
81 | int nr_to_call, int *nr_calls) | |
fe9d4f57 AD |
82 | { |
83 | int ret = NOTIFY_DONE; | |
84 | struct notifier_block *nb, *next_nb; | |
85 | ||
d11c563d | 86 | nb = rcu_dereference_raw(*nl); |
fe9d4f57 AD |
87 | |
88 | while (nb && nr_to_call) { | |
d11c563d | 89 | next_nb = rcu_dereference_raw(nb->next); |
1b2439db AV |
90 | |
91 | #ifdef CONFIG_DEBUG_NOTIFIERS | |
ab7476cf | 92 | if (unlikely(!func_ptr_is_kernel_text(nb->notifier_call))) { |
1b2439db AV |
93 | WARN(1, "Invalid notifier called!"); |
94 | nb = next_nb; | |
95 | continue; | |
96 | } | |
97 | #endif | |
fe9d4f57 AD |
98 | ret = nb->notifier_call(nb, val, v); |
99 | ||
100 | if (nr_calls) | |
101 | (*nr_calls)++; | |
102 | ||
3e6daded | 103 | if (ret & NOTIFY_STOP_MASK) |
fe9d4f57 AD |
104 | break; |
105 | nb = next_nb; | |
106 | nr_to_call--; | |
107 | } | |
108 | return ret; | |
109 | } | |
b40a2cb6 | 110 | NOKPROBE_SYMBOL(notifier_call_chain); |
fe9d4f57 AD |
111 | |
112 | /* | |
113 | * Atomic notifier chain routines. Registration and unregistration | |
114 | * use a spinlock, and call_chain is synchronized by RCU (no locks). | |
115 | */ | |
116 | ||
117 | /** | |
118 | * atomic_notifier_chain_register - Add notifier to an atomic notifier chain | |
119 | * @nh: Pointer to head of the atomic notifier chain | |
120 | * @n: New entry in notifier chain | |
121 | * | |
122 | * Adds a notifier to an atomic notifier chain. | |
123 | * | |
124 | * Currently always returns zero. | |
125 | */ | |
126 | int atomic_notifier_chain_register(struct atomic_notifier_head *nh, | |
127 | struct notifier_block *n) | |
128 | { | |
129 | unsigned long flags; | |
130 | int ret; | |
131 | ||
132 | spin_lock_irqsave(&nh->lock, flags); | |
133 | ret = notifier_chain_register(&nh->head, n); | |
134 | spin_unlock_irqrestore(&nh->lock, flags); | |
135 | return ret; | |
136 | } | |
137 | EXPORT_SYMBOL_GPL(atomic_notifier_chain_register); | |
138 | ||
139 | /** | |
140 | * atomic_notifier_chain_unregister - Remove notifier from an atomic notifier chain | |
141 | * @nh: Pointer to head of the atomic notifier chain | |
142 | * @n: Entry to remove from notifier chain | |
143 | * | |
144 | * Removes a notifier from an atomic notifier chain. | |
145 | * | |
146 | * Returns zero on success or %-ENOENT on failure. | |
147 | */ | |
148 | int atomic_notifier_chain_unregister(struct atomic_notifier_head *nh, | |
149 | struct notifier_block *n) | |
150 | { | |
151 | unsigned long flags; | |
152 | int ret; | |
153 | ||
154 | spin_lock_irqsave(&nh->lock, flags); | |
155 | ret = notifier_chain_unregister(&nh->head, n); | |
156 | spin_unlock_irqrestore(&nh->lock, flags); | |
157 | synchronize_rcu(); | |
158 | return ret; | |
159 | } | |
160 | EXPORT_SYMBOL_GPL(atomic_notifier_chain_unregister); | |
161 | ||
162 | /** | |
163 | * __atomic_notifier_call_chain - Call functions in an atomic notifier chain | |
164 | * @nh: Pointer to head of the atomic notifier chain | |
165 | * @val: Value passed unmodified to notifier function | |
166 | * @v: Pointer passed unmodified to notifier function | |
167 | * @nr_to_call: See the comment for notifier_call_chain. | |
168 | * @nr_calls: See the comment for notifier_call_chain. | |
169 | * | |
170 | * Calls each function in a notifier chain in turn. The functions | |
171 | * run in an atomic context, so they must not block. | |
172 | * This routine uses RCU to synchronize with changes to the chain. | |
173 | * | |
174 | * If the return value of the notifier can be and'ed | |
175 | * with %NOTIFY_STOP_MASK then atomic_notifier_call_chain() | |
176 | * will return immediately, with the return value of | |
177 | * the notifier function which halted execution. | |
178 | * Otherwise the return value is the return value | |
179 | * of the last notifier function called. | |
180 | */ | |
b40a2cb6 MH |
181 | int __atomic_notifier_call_chain(struct atomic_notifier_head *nh, |
182 | unsigned long val, void *v, | |
183 | int nr_to_call, int *nr_calls) | |
fe9d4f57 AD |
184 | { |
185 | int ret; | |
186 | ||
187 | rcu_read_lock(); | |
188 | ret = notifier_call_chain(&nh->head, val, v, nr_to_call, nr_calls); | |
189 | rcu_read_unlock(); | |
190 | return ret; | |
191 | } | |
192 | EXPORT_SYMBOL_GPL(__atomic_notifier_call_chain); | |
b40a2cb6 | 193 | NOKPROBE_SYMBOL(__atomic_notifier_call_chain); |
fe9d4f57 | 194 | |
b40a2cb6 MH |
195 | int atomic_notifier_call_chain(struct atomic_notifier_head *nh, |
196 | unsigned long val, void *v) | |
fe9d4f57 AD |
197 | { |
198 | return __atomic_notifier_call_chain(nh, val, v, -1, NULL); | |
199 | } | |
200 | EXPORT_SYMBOL_GPL(atomic_notifier_call_chain); | |
b40a2cb6 | 201 | NOKPROBE_SYMBOL(atomic_notifier_call_chain); |
fe9d4f57 AD |
202 | |
203 | /* | |
204 | * Blocking notifier chain routines. All access to the chain is | |
205 | * synchronized by an rwsem. | |
206 | */ | |
207 | ||
208 | /** | |
209 | * blocking_notifier_chain_register - Add notifier to a blocking notifier chain | |
210 | * @nh: Pointer to head of the blocking notifier chain | |
211 | * @n: New entry in notifier chain | |
212 | * | |
213 | * Adds a notifier to a blocking notifier chain. | |
214 | * Must be called in process context. | |
215 | * | |
216 | * Currently always returns zero. | |
217 | */ | |
218 | int blocking_notifier_chain_register(struct blocking_notifier_head *nh, | |
219 | struct notifier_block *n) | |
220 | { | |
221 | int ret; | |
222 | ||
223 | /* | |
224 | * This code gets used during boot-up, when task switching is | |
225 | * not yet working and interrupts must remain disabled. At | |
226 | * such times we must not call down_write(). | |
227 | */ | |
228 | if (unlikely(system_state == SYSTEM_BOOTING)) | |
229 | return notifier_chain_register(&nh->head, n); | |
230 | ||
231 | down_write(&nh->rwsem); | |
232 | ret = notifier_chain_register(&nh->head, n); | |
233 | up_write(&nh->rwsem); | |
234 | return ret; | |
235 | } | |
236 | EXPORT_SYMBOL_GPL(blocking_notifier_chain_register); | |
237 | ||
6546bc42 ND |
238 | /** |
239 | * blocking_notifier_chain_cond_register - Cond add notifier to a blocking notifier chain | |
240 | * @nh: Pointer to head of the blocking notifier chain | |
241 | * @n: New entry in notifier chain | |
242 | * | |
243 | * Adds a notifier to a blocking notifier chain, only if not already | |
244 | * present in the chain. | |
245 | * Must be called in process context. | |
246 | * | |
247 | * Currently always returns zero. | |
248 | */ | |
249 | int blocking_notifier_chain_cond_register(struct blocking_notifier_head *nh, | |
250 | struct notifier_block *n) | |
251 | { | |
252 | int ret; | |
253 | ||
254 | down_write(&nh->rwsem); | |
255 | ret = notifier_chain_cond_register(&nh->head, n); | |
256 | up_write(&nh->rwsem); | |
257 | return ret; | |
258 | } | |
259 | EXPORT_SYMBOL_GPL(blocking_notifier_chain_cond_register); | |
260 | ||
fe9d4f57 AD |
261 | /** |
262 | * blocking_notifier_chain_unregister - Remove notifier from a blocking notifier chain | |
263 | * @nh: Pointer to head of the blocking notifier chain | |
264 | * @n: Entry to remove from notifier chain | |
265 | * | |
266 | * Removes a notifier from a blocking notifier chain. | |
267 | * Must be called from process context. | |
268 | * | |
269 | * Returns zero on success or %-ENOENT on failure. | |
270 | */ | |
271 | int blocking_notifier_chain_unregister(struct blocking_notifier_head *nh, | |
272 | struct notifier_block *n) | |
273 | { | |
274 | int ret; | |
275 | ||
276 | /* | |
277 | * This code gets used during boot-up, when task switching is | |
278 | * not yet working and interrupts must remain disabled. At | |
279 | * such times we must not call down_write(). | |
280 | */ | |
281 | if (unlikely(system_state == SYSTEM_BOOTING)) | |
282 | return notifier_chain_unregister(&nh->head, n); | |
283 | ||
284 | down_write(&nh->rwsem); | |
285 | ret = notifier_chain_unregister(&nh->head, n); | |
286 | up_write(&nh->rwsem); | |
287 | return ret; | |
288 | } | |
289 | EXPORT_SYMBOL_GPL(blocking_notifier_chain_unregister); | |
290 | ||
291 | /** | |
292 | * __blocking_notifier_call_chain - Call functions in a blocking notifier chain | |
293 | * @nh: Pointer to head of the blocking notifier chain | |
294 | * @val: Value passed unmodified to notifier function | |
295 | * @v: Pointer passed unmodified to notifier function | |
296 | * @nr_to_call: See comment for notifier_call_chain. | |
297 | * @nr_calls: See comment for notifier_call_chain. | |
298 | * | |
299 | * Calls each function in a notifier chain in turn. The functions | |
300 | * run in a process context, so they are allowed to block. | |
301 | * | |
302 | * If the return value of the notifier can be and'ed | |
303 | * with %NOTIFY_STOP_MASK then blocking_notifier_call_chain() | |
304 | * will return immediately, with the return value of | |
305 | * the notifier function which halted execution. | |
306 | * Otherwise the return value is the return value | |
307 | * of the last notifier function called. | |
308 | */ | |
309 | int __blocking_notifier_call_chain(struct blocking_notifier_head *nh, | |
310 | unsigned long val, void *v, | |
311 | int nr_to_call, int *nr_calls) | |
312 | { | |
313 | int ret = NOTIFY_DONE; | |
314 | ||
315 | /* | |
316 | * We check the head outside the lock, but if this access is | |
317 | * racy then it does not matter what the result of the test | |
318 | * is, we re-check the list after having taken the lock anyway: | |
319 | */ | |
8857563b | 320 | if (rcu_access_pointer(nh->head)) { |
fe9d4f57 AD |
321 | down_read(&nh->rwsem); |
322 | ret = notifier_call_chain(&nh->head, val, v, nr_to_call, | |
323 | nr_calls); | |
324 | up_read(&nh->rwsem); | |
325 | } | |
326 | return ret; | |
327 | } | |
328 | EXPORT_SYMBOL_GPL(__blocking_notifier_call_chain); | |
329 | ||
330 | int blocking_notifier_call_chain(struct blocking_notifier_head *nh, | |
331 | unsigned long val, void *v) | |
332 | { | |
333 | return __blocking_notifier_call_chain(nh, val, v, -1, NULL); | |
334 | } | |
335 | EXPORT_SYMBOL_GPL(blocking_notifier_call_chain); | |
336 | ||
337 | /* | |
338 | * Raw notifier chain routines. There is no protection; | |
339 | * the caller must provide it. Use at your own risk! | |
340 | */ | |
341 | ||
342 | /** | |
343 | * raw_notifier_chain_register - Add notifier to a raw notifier chain | |
344 | * @nh: Pointer to head of the raw notifier chain | |
345 | * @n: New entry in notifier chain | |
346 | * | |
347 | * Adds a notifier to a raw notifier chain. | |
348 | * All locking must be provided by the caller. | |
349 | * | |
350 | * Currently always returns zero. | |
351 | */ | |
352 | int raw_notifier_chain_register(struct raw_notifier_head *nh, | |
353 | struct notifier_block *n) | |
354 | { | |
355 | return notifier_chain_register(&nh->head, n); | |
356 | } | |
357 | EXPORT_SYMBOL_GPL(raw_notifier_chain_register); | |
358 | ||
359 | /** | |
360 | * raw_notifier_chain_unregister - Remove notifier from a raw notifier chain | |
361 | * @nh: Pointer to head of the raw notifier chain | |
362 | * @n: Entry to remove from notifier chain | |
363 | * | |
364 | * Removes a notifier from a raw notifier chain. | |
365 | * All locking must be provided by the caller. | |
366 | * | |
367 | * Returns zero on success or %-ENOENT on failure. | |
368 | */ | |
369 | int raw_notifier_chain_unregister(struct raw_notifier_head *nh, | |
370 | struct notifier_block *n) | |
371 | { | |
372 | return notifier_chain_unregister(&nh->head, n); | |
373 | } | |
374 | EXPORT_SYMBOL_GPL(raw_notifier_chain_unregister); | |
375 | ||
376 | /** | |
377 | * __raw_notifier_call_chain - Call functions in a raw notifier chain | |
378 | * @nh: Pointer to head of the raw notifier chain | |
379 | * @val: Value passed unmodified to notifier function | |
380 | * @v: Pointer passed unmodified to notifier function | |
381 | * @nr_to_call: See comment for notifier_call_chain. | |
382 | * @nr_calls: See comment for notifier_call_chain | |
383 | * | |
384 | * Calls each function in a notifier chain in turn. The functions | |
385 | * run in an undefined context. | |
386 | * All locking must be provided by the caller. | |
387 | * | |
388 | * If the return value of the notifier can be and'ed | |
389 | * with %NOTIFY_STOP_MASK then raw_notifier_call_chain() | |
390 | * will return immediately, with the return value of | |
391 | * the notifier function which halted execution. | |
392 | * Otherwise the return value is the return value | |
393 | * of the last notifier function called. | |
394 | */ | |
395 | int __raw_notifier_call_chain(struct raw_notifier_head *nh, | |
396 | unsigned long val, void *v, | |
397 | int nr_to_call, int *nr_calls) | |
398 | { | |
399 | return notifier_call_chain(&nh->head, val, v, nr_to_call, nr_calls); | |
400 | } | |
401 | EXPORT_SYMBOL_GPL(__raw_notifier_call_chain); | |
402 | ||
403 | int raw_notifier_call_chain(struct raw_notifier_head *nh, | |
404 | unsigned long val, void *v) | |
405 | { | |
406 | return __raw_notifier_call_chain(nh, val, v, -1, NULL); | |
407 | } | |
408 | EXPORT_SYMBOL_GPL(raw_notifier_call_chain); | |
409 | ||
83fe27ea | 410 | #ifdef CONFIG_SRCU |
fe9d4f57 AD |
411 | /* |
412 | * SRCU notifier chain routines. Registration and unregistration | |
413 | * use a mutex, and call_chain is synchronized by SRCU (no locks). | |
414 | */ | |
415 | ||
416 | /** | |
417 | * srcu_notifier_chain_register - Add notifier to an SRCU notifier chain | |
418 | * @nh: Pointer to head of the SRCU notifier chain | |
419 | * @n: New entry in notifier chain | |
420 | * | |
421 | * Adds a notifier to an SRCU notifier chain. | |
422 | * Must be called in process context. | |
423 | * | |
424 | * Currently always returns zero. | |
425 | */ | |
426 | int srcu_notifier_chain_register(struct srcu_notifier_head *nh, | |
427 | struct notifier_block *n) | |
428 | { | |
429 | int ret; | |
430 | ||
431 | /* | |
432 | * This code gets used during boot-up, when task switching is | |
433 | * not yet working and interrupts must remain disabled. At | |
434 | * such times we must not call mutex_lock(). | |
435 | */ | |
436 | if (unlikely(system_state == SYSTEM_BOOTING)) | |
437 | return notifier_chain_register(&nh->head, n); | |
438 | ||
439 | mutex_lock(&nh->mutex); | |
440 | ret = notifier_chain_register(&nh->head, n); | |
441 | mutex_unlock(&nh->mutex); | |
442 | return ret; | |
443 | } | |
444 | EXPORT_SYMBOL_GPL(srcu_notifier_chain_register); | |
445 | ||
446 | /** | |
447 | * srcu_notifier_chain_unregister - Remove notifier from an SRCU notifier chain | |
448 | * @nh: Pointer to head of the SRCU notifier chain | |
449 | * @n: Entry to remove from notifier chain | |
450 | * | |
451 | * Removes a notifier from an SRCU notifier chain. | |
452 | * Must be called from process context. | |
453 | * | |
454 | * Returns zero on success or %-ENOENT on failure. | |
455 | */ | |
456 | int srcu_notifier_chain_unregister(struct srcu_notifier_head *nh, | |
457 | struct notifier_block *n) | |
458 | { | |
459 | int ret; | |
460 | ||
461 | /* | |
462 | * This code gets used during boot-up, when task switching is | |
463 | * not yet working and interrupts must remain disabled. At | |
464 | * such times we must not call mutex_lock(). | |
465 | */ | |
466 | if (unlikely(system_state == SYSTEM_BOOTING)) | |
467 | return notifier_chain_unregister(&nh->head, n); | |
468 | ||
469 | mutex_lock(&nh->mutex); | |
470 | ret = notifier_chain_unregister(&nh->head, n); | |
471 | mutex_unlock(&nh->mutex); | |
472 | synchronize_srcu(&nh->srcu); | |
473 | return ret; | |
474 | } | |
475 | EXPORT_SYMBOL_GPL(srcu_notifier_chain_unregister); | |
476 | ||
477 | /** | |
478 | * __srcu_notifier_call_chain - Call functions in an SRCU notifier chain | |
479 | * @nh: Pointer to head of the SRCU notifier chain | |
480 | * @val: Value passed unmodified to notifier function | |
481 | * @v: Pointer passed unmodified to notifier function | |
482 | * @nr_to_call: See comment for notifier_call_chain. | |
483 | * @nr_calls: See comment for notifier_call_chain | |
484 | * | |
485 | * Calls each function in a notifier chain in turn. The functions | |
486 | * run in a process context, so they are allowed to block. | |
487 | * | |
488 | * If the return value of the notifier can be and'ed | |
489 | * with %NOTIFY_STOP_MASK then srcu_notifier_call_chain() | |
490 | * will return immediately, with the return value of | |
491 | * the notifier function which halted execution. | |
492 | * Otherwise the return value is the return value | |
493 | * of the last notifier function called. | |
494 | */ | |
495 | int __srcu_notifier_call_chain(struct srcu_notifier_head *nh, | |
496 | unsigned long val, void *v, | |
497 | int nr_to_call, int *nr_calls) | |
498 | { | |
499 | int ret; | |
500 | int idx; | |
501 | ||
502 | idx = srcu_read_lock(&nh->srcu); | |
503 | ret = notifier_call_chain(&nh->head, val, v, nr_to_call, nr_calls); | |
504 | srcu_read_unlock(&nh->srcu, idx); | |
505 | return ret; | |
506 | } | |
507 | EXPORT_SYMBOL_GPL(__srcu_notifier_call_chain); | |
508 | ||
509 | int srcu_notifier_call_chain(struct srcu_notifier_head *nh, | |
510 | unsigned long val, void *v) | |
511 | { | |
512 | return __srcu_notifier_call_chain(nh, val, v, -1, NULL); | |
513 | } | |
514 | EXPORT_SYMBOL_GPL(srcu_notifier_call_chain); | |
515 | ||
516 | /** | |
517 | * srcu_init_notifier_head - Initialize an SRCU notifier head | |
518 | * @nh: Pointer to head of the srcu notifier chain | |
519 | * | |
520 | * Unlike other sorts of notifier heads, SRCU notifier heads require | |
521 | * dynamic initialization. Be sure to call this routine before | |
522 | * calling any of the other SRCU notifier routines for this head. | |
523 | * | |
524 | * If an SRCU notifier head is deallocated, it must first be cleaned | |
525 | * up by calling srcu_cleanup_notifier_head(). Otherwise the head's | |
526 | * per-cpu data (used by the SRCU mechanism) will leak. | |
527 | */ | |
528 | void srcu_init_notifier_head(struct srcu_notifier_head *nh) | |
529 | { | |
530 | mutex_init(&nh->mutex); | |
531 | if (init_srcu_struct(&nh->srcu) < 0) | |
532 | BUG(); | |
533 | nh->head = NULL; | |
534 | } | |
535 | EXPORT_SYMBOL_GPL(srcu_init_notifier_head); | |
536 | ||
83fe27ea PK |
537 | #endif /* CONFIG_SRCU */ |
538 | ||
fe9d4f57 AD |
539 | static ATOMIC_NOTIFIER_HEAD(die_chain); |
540 | ||
b40a2cb6 | 541 | int notrace notify_die(enum die_val val, const char *str, |
fe9d4f57 AD |
542 | struct pt_regs *regs, long err, int trap, int sig) |
543 | { | |
544 | struct die_args args = { | |
545 | .regs = regs, | |
546 | .str = str, | |
547 | .err = err, | |
548 | .trapnr = trap, | |
549 | .signr = sig, | |
550 | ||
551 | }; | |
5778077d | 552 | RCU_LOCKDEP_WARN(!rcu_is_watching(), |
e727c7d7 | 553 | "notify_die called but RCU thinks we're quiescent"); |
fe9d4f57 AD |
554 | return atomic_notifier_call_chain(&die_chain, val, &args); |
555 | } | |
b40a2cb6 | 556 | NOKPROBE_SYMBOL(notify_die); |
fe9d4f57 AD |
557 | |
558 | int register_die_notifier(struct notifier_block *nb) | |
559 | { | |
d44d71bb | 560 | vmalloc_sync_mappings(); |
fe9d4f57 AD |
561 | return atomic_notifier_chain_register(&die_chain, nb); |
562 | } | |
563 | EXPORT_SYMBOL_GPL(register_die_notifier); | |
564 | ||
565 | int unregister_die_notifier(struct notifier_block *nb) | |
566 | { | |
567 | return atomic_notifier_chain_unregister(&die_chain, nb); | |
568 | } | |
569 | EXPORT_SYMBOL_GPL(unregister_die_notifier); |