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fe9d4f57 AD |
1 | #include <linux/kdebug.h> |
2 | #include <linux/kprobes.h> | |
3 | #include <linux/module.h> | |
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 | { | |
1b2439db AV |
24 | if (!kernel_text_address((unsigned long)n->notifier_call)) { |
25 | WARN(1, "Invalid notifier registered!"); | |
26 | return 0; | |
27 | } | |
fe9d4f57 AD |
28 | while ((*nl) != NULL) { |
29 | if (n->priority > (*nl)->priority) | |
30 | break; | |
31 | nl = &((*nl)->next); | |
32 | } | |
33 | n->next = *nl; | |
34 | rcu_assign_pointer(*nl, n); | |
35 | return 0; | |
36 | } | |
37 | ||
6546bc42 ND |
38 | static int notifier_chain_cond_register(struct notifier_block **nl, |
39 | struct notifier_block *n) | |
40 | { | |
1b2439db AV |
41 | if (!kernel_text_address((unsigned long)n->notifier_call)) { |
42 | WARN(1, "Invalid notifier registered!"); | |
43 | return 0; | |
44 | } | |
6546bc42 ND |
45 | while ((*nl) != NULL) { |
46 | if ((*nl) == n) | |
47 | return 0; | |
48 | if (n->priority > (*nl)->priority) | |
49 | break; | |
50 | nl = &((*nl)->next); | |
51 | } | |
52 | n->next = *nl; | |
53 | rcu_assign_pointer(*nl, n); | |
54 | return 0; | |
55 | } | |
56 | ||
fe9d4f57 AD |
57 | static int notifier_chain_unregister(struct notifier_block **nl, |
58 | struct notifier_block *n) | |
59 | { | |
60 | while ((*nl) != NULL) { | |
61 | if ((*nl) == n) { | |
62 | rcu_assign_pointer(*nl, n->next); | |
63 | return 0; | |
64 | } | |
65 | nl = &((*nl)->next); | |
66 | } | |
67 | return -ENOENT; | |
68 | } | |
69 | ||
70 | /** | |
71 | * notifier_call_chain - Informs the registered notifiers about an event. | |
72 | * @nl: Pointer to head of the blocking notifier chain | |
73 | * @val: Value passed unmodified to notifier function | |
74 | * @v: Pointer passed unmodified to notifier function | |
75 | * @nr_to_call: Number of notifier functions to be called. Don't care | |
76 | * value of this parameter is -1. | |
77 | * @nr_calls: Records the number of notifications sent. Don't care | |
78 | * value of this field is NULL. | |
79 | * @returns: notifier_call_chain returns the value returned by the | |
80 | * last notifier function called. | |
81 | */ | |
82 | static int __kprobes notifier_call_chain(struct notifier_block **nl, | |
83 | unsigned long val, void *v, | |
84 | int nr_to_call, int *nr_calls) | |
85 | { | |
86 | int ret = NOTIFY_DONE; | |
87 | struct notifier_block *nb, *next_nb; | |
88 | ||
89 | nb = rcu_dereference(*nl); | |
90 | ||
91 | while (nb && nr_to_call) { | |
92 | next_nb = rcu_dereference(nb->next); | |
1b2439db AV |
93 | |
94 | #ifdef CONFIG_DEBUG_NOTIFIERS | |
95 | if (!kernel_text_address((unsigned long)nb->notifier_call)) { | |
96 | WARN(1, "Invalid notifier called!"); | |
97 | nb = next_nb; | |
98 | continue; | |
99 | } | |
100 | #endif | |
fe9d4f57 AD |
101 | ret = nb->notifier_call(nb, val, v); |
102 | ||
103 | if (nr_calls) | |
104 | (*nr_calls)++; | |
105 | ||
106 | if ((ret & NOTIFY_STOP_MASK) == NOTIFY_STOP_MASK) | |
107 | break; | |
108 | nb = next_nb; | |
109 | nr_to_call--; | |
110 | } | |
111 | return ret; | |
112 | } | |
113 | ||
114 | /* | |
115 | * Atomic notifier chain routines. Registration and unregistration | |
116 | * use a spinlock, and call_chain is synchronized by RCU (no locks). | |
117 | */ | |
118 | ||
119 | /** | |
120 | * atomic_notifier_chain_register - Add notifier to an atomic notifier chain | |
121 | * @nh: Pointer to head of the atomic notifier chain | |
122 | * @n: New entry in notifier chain | |
123 | * | |
124 | * Adds a notifier to an atomic notifier chain. | |
125 | * | |
126 | * Currently always returns zero. | |
127 | */ | |
128 | int atomic_notifier_chain_register(struct atomic_notifier_head *nh, | |
129 | struct notifier_block *n) | |
130 | { | |
131 | unsigned long flags; | |
132 | int ret; | |
133 | ||
134 | spin_lock_irqsave(&nh->lock, flags); | |
135 | ret = notifier_chain_register(&nh->head, n); | |
136 | spin_unlock_irqrestore(&nh->lock, flags); | |
137 | return ret; | |
138 | } | |
139 | EXPORT_SYMBOL_GPL(atomic_notifier_chain_register); | |
140 | ||
141 | /** | |
142 | * atomic_notifier_chain_unregister - Remove notifier from an atomic notifier chain | |
143 | * @nh: Pointer to head of the atomic notifier chain | |
144 | * @n: Entry to remove from notifier chain | |
145 | * | |
146 | * Removes a notifier from an atomic notifier chain. | |
147 | * | |
148 | * Returns zero on success or %-ENOENT on failure. | |
149 | */ | |
150 | int atomic_notifier_chain_unregister(struct atomic_notifier_head *nh, | |
151 | struct notifier_block *n) | |
152 | { | |
153 | unsigned long flags; | |
154 | int ret; | |
155 | ||
156 | spin_lock_irqsave(&nh->lock, flags); | |
157 | ret = notifier_chain_unregister(&nh->head, n); | |
158 | spin_unlock_irqrestore(&nh->lock, flags); | |
159 | synchronize_rcu(); | |
160 | return ret; | |
161 | } | |
162 | EXPORT_SYMBOL_GPL(atomic_notifier_chain_unregister); | |
163 | ||
164 | /** | |
165 | * __atomic_notifier_call_chain - Call functions in an atomic notifier chain | |
166 | * @nh: Pointer to head of the atomic notifier chain | |
167 | * @val: Value passed unmodified to notifier function | |
168 | * @v: Pointer passed unmodified to notifier function | |
169 | * @nr_to_call: See the comment for notifier_call_chain. | |
170 | * @nr_calls: See the comment for notifier_call_chain. | |
171 | * | |
172 | * Calls each function in a notifier chain in turn. The functions | |
173 | * run in an atomic context, so they must not block. | |
174 | * This routine uses RCU to synchronize with changes to the chain. | |
175 | * | |
176 | * If the return value of the notifier can be and'ed | |
177 | * with %NOTIFY_STOP_MASK then atomic_notifier_call_chain() | |
178 | * will return immediately, with the return value of | |
179 | * the notifier function which halted execution. | |
180 | * Otherwise the return value is the return value | |
181 | * of the last notifier function called. | |
182 | */ | |
183 | int __kprobes __atomic_notifier_call_chain(struct atomic_notifier_head *nh, | |
184 | unsigned long val, void *v, | |
185 | int nr_to_call, int *nr_calls) | |
186 | { | |
187 | int ret; | |
188 | ||
189 | rcu_read_lock(); | |
190 | ret = notifier_call_chain(&nh->head, val, v, nr_to_call, nr_calls); | |
191 | rcu_read_unlock(); | |
192 | return ret; | |
193 | } | |
194 | EXPORT_SYMBOL_GPL(__atomic_notifier_call_chain); | |
195 | ||
196 | int __kprobes atomic_notifier_call_chain(struct atomic_notifier_head *nh, | |
197 | unsigned long val, void *v) | |
198 | { | |
199 | return __atomic_notifier_call_chain(nh, val, v, -1, NULL); | |
200 | } | |
201 | EXPORT_SYMBOL_GPL(atomic_notifier_call_chain); | |
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 | */ | |
320 | if (rcu_dereference(nh->head)) { | |
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 | ||
410 | /* | |
411 | * SRCU notifier chain routines. Registration and unregistration | |
412 | * use a mutex, and call_chain is synchronized by SRCU (no locks). | |
413 | */ | |
414 | ||
415 | /** | |
416 | * srcu_notifier_chain_register - Add notifier to an SRCU notifier chain | |
417 | * @nh: Pointer to head of the SRCU notifier chain | |
418 | * @n: New entry in notifier chain | |
419 | * | |
420 | * Adds a notifier to an SRCU notifier chain. | |
421 | * Must be called in process context. | |
422 | * | |
423 | * Currently always returns zero. | |
424 | */ | |
425 | int srcu_notifier_chain_register(struct srcu_notifier_head *nh, | |
426 | struct notifier_block *n) | |
427 | { | |
428 | int ret; | |
429 | ||
430 | /* | |
431 | * This code gets used during boot-up, when task switching is | |
432 | * not yet working and interrupts must remain disabled. At | |
433 | * such times we must not call mutex_lock(). | |
434 | */ | |
435 | if (unlikely(system_state == SYSTEM_BOOTING)) | |
436 | return notifier_chain_register(&nh->head, n); | |
437 | ||
438 | mutex_lock(&nh->mutex); | |
439 | ret = notifier_chain_register(&nh->head, n); | |
440 | mutex_unlock(&nh->mutex); | |
441 | return ret; | |
442 | } | |
443 | EXPORT_SYMBOL_GPL(srcu_notifier_chain_register); | |
444 | ||
445 | /** | |
446 | * srcu_notifier_chain_unregister - Remove notifier from an SRCU notifier chain | |
447 | * @nh: Pointer to head of the SRCU notifier chain | |
448 | * @n: Entry to remove from notifier chain | |
449 | * | |
450 | * Removes a notifier from an SRCU notifier chain. | |
451 | * Must be called from process context. | |
452 | * | |
453 | * Returns zero on success or %-ENOENT on failure. | |
454 | */ | |
455 | int srcu_notifier_chain_unregister(struct srcu_notifier_head *nh, | |
456 | struct notifier_block *n) | |
457 | { | |
458 | int ret; | |
459 | ||
460 | /* | |
461 | * This code gets used during boot-up, when task switching is | |
462 | * not yet working and interrupts must remain disabled. At | |
463 | * such times we must not call mutex_lock(). | |
464 | */ | |
465 | if (unlikely(system_state == SYSTEM_BOOTING)) | |
466 | return notifier_chain_unregister(&nh->head, n); | |
467 | ||
468 | mutex_lock(&nh->mutex); | |
469 | ret = notifier_chain_unregister(&nh->head, n); | |
470 | mutex_unlock(&nh->mutex); | |
471 | synchronize_srcu(&nh->srcu); | |
472 | return ret; | |
473 | } | |
474 | EXPORT_SYMBOL_GPL(srcu_notifier_chain_unregister); | |
475 | ||
476 | /** | |
477 | * __srcu_notifier_call_chain - Call functions in an SRCU notifier chain | |
478 | * @nh: Pointer to head of the SRCU notifier chain | |
479 | * @val: Value passed unmodified to notifier function | |
480 | * @v: Pointer passed unmodified to notifier function | |
481 | * @nr_to_call: See comment for notifier_call_chain. | |
482 | * @nr_calls: See comment for notifier_call_chain | |
483 | * | |
484 | * Calls each function in a notifier chain in turn. The functions | |
485 | * run in a process context, so they are allowed to block. | |
486 | * | |
487 | * If the return value of the notifier can be and'ed | |
488 | * with %NOTIFY_STOP_MASK then srcu_notifier_call_chain() | |
489 | * will return immediately, with the return value of | |
490 | * the notifier function which halted execution. | |
491 | * Otherwise the return value is the return value | |
492 | * of the last notifier function called. | |
493 | */ | |
494 | int __srcu_notifier_call_chain(struct srcu_notifier_head *nh, | |
495 | unsigned long val, void *v, | |
496 | int nr_to_call, int *nr_calls) | |
497 | { | |
498 | int ret; | |
499 | int idx; | |
500 | ||
501 | idx = srcu_read_lock(&nh->srcu); | |
502 | ret = notifier_call_chain(&nh->head, val, v, nr_to_call, nr_calls); | |
503 | srcu_read_unlock(&nh->srcu, idx); | |
504 | return ret; | |
505 | } | |
506 | EXPORT_SYMBOL_GPL(__srcu_notifier_call_chain); | |
507 | ||
508 | int srcu_notifier_call_chain(struct srcu_notifier_head *nh, | |
509 | unsigned long val, void *v) | |
510 | { | |
511 | return __srcu_notifier_call_chain(nh, val, v, -1, NULL); | |
512 | } | |
513 | EXPORT_SYMBOL_GPL(srcu_notifier_call_chain); | |
514 | ||
515 | /** | |
516 | * srcu_init_notifier_head - Initialize an SRCU notifier head | |
517 | * @nh: Pointer to head of the srcu notifier chain | |
518 | * | |
519 | * Unlike other sorts of notifier heads, SRCU notifier heads require | |
520 | * dynamic initialization. Be sure to call this routine before | |
521 | * calling any of the other SRCU notifier routines for this head. | |
522 | * | |
523 | * If an SRCU notifier head is deallocated, it must first be cleaned | |
524 | * up by calling srcu_cleanup_notifier_head(). Otherwise the head's | |
525 | * per-cpu data (used by the SRCU mechanism) will leak. | |
526 | */ | |
527 | void srcu_init_notifier_head(struct srcu_notifier_head *nh) | |
528 | { | |
529 | mutex_init(&nh->mutex); | |
530 | if (init_srcu_struct(&nh->srcu) < 0) | |
531 | BUG(); | |
532 | nh->head = NULL; | |
533 | } | |
534 | EXPORT_SYMBOL_GPL(srcu_init_notifier_head); | |
535 | ||
536 | /** | |
537 | * register_reboot_notifier - Register function to be called at reboot time | |
538 | * @nb: Info about notifier function to be called | |
539 | * | |
540 | * Registers a function with the list of functions | |
541 | * to be called at reboot time. | |
542 | * | |
543 | * Currently always returns zero, as blocking_notifier_chain_register() | |
544 | * always returns zero. | |
545 | */ | |
546 | int register_reboot_notifier(struct notifier_block *nb) | |
547 | { | |
548 | return blocking_notifier_chain_register(&reboot_notifier_list, nb); | |
549 | } | |
550 | EXPORT_SYMBOL(register_reboot_notifier); | |
551 | ||
552 | /** | |
553 | * unregister_reboot_notifier - Unregister previously registered reboot notifier | |
554 | * @nb: Hook to be unregistered | |
555 | * | |
556 | * Unregisters a previously registered reboot | |
557 | * notifier function. | |
558 | * | |
559 | * Returns zero on success, or %-ENOENT on failure. | |
560 | */ | |
561 | int unregister_reboot_notifier(struct notifier_block *nb) | |
562 | { | |
563 | return blocking_notifier_chain_unregister(&reboot_notifier_list, nb); | |
564 | } | |
565 | EXPORT_SYMBOL(unregister_reboot_notifier); | |
566 | ||
567 | static ATOMIC_NOTIFIER_HEAD(die_chain); | |
568 | ||
569 | int notify_die(enum die_val val, const char *str, | |
570 | struct pt_regs *regs, long err, int trap, int sig) | |
571 | { | |
572 | struct die_args args = { | |
573 | .regs = regs, | |
574 | .str = str, | |
575 | .err = err, | |
576 | .trapnr = trap, | |
577 | .signr = sig, | |
578 | ||
579 | }; | |
580 | return atomic_notifier_call_chain(&die_chain, val, &args); | |
581 | } | |
582 | ||
583 | int register_die_notifier(struct notifier_block *nb) | |
584 | { | |
585 | vmalloc_sync_all(); | |
586 | return atomic_notifier_chain_register(&die_chain, nb); | |
587 | } | |
588 | EXPORT_SYMBOL_GPL(register_die_notifier); | |
589 | ||
590 | int unregister_die_notifier(struct notifier_block *nb) | |
591 | { | |
592 | return atomic_notifier_chain_unregister(&die_chain, nb); | |
593 | } | |
594 | EXPORT_SYMBOL_GPL(unregister_die_notifier); |