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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) { | |
1a50cb80 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 | ||
39 | static int notifier_chain_unregister(struct notifier_block **nl, | |
40 | struct notifier_block *n) | |
41 | { | |
42 | while ((*nl) != NULL) { | |
43 | if ((*nl) == n) { | |
44 | rcu_assign_pointer(*nl, n->next); | |
45 | return 0; | |
46 | } | |
47 | nl = &((*nl)->next); | |
48 | } | |
49 | return -ENOENT; | |
50 | } | |
51 | ||
52 | /** | |
53 | * notifier_call_chain - Informs the registered notifiers about an event. | |
54 | * @nl: Pointer to head of the blocking notifier chain | |
55 | * @val: Value passed unmodified to notifier function | |
56 | * @v: Pointer passed unmodified to notifier function | |
57 | * @nr_to_call: Number of notifier functions to be called. Don't care | |
58 | * value of this parameter is -1. | |
59 | * @nr_calls: Records the number of notifications sent. Don't care | |
60 | * value of this field is NULL. | |
61 | * @returns: notifier_call_chain returns the value returned by the | |
62 | * last notifier function called. | |
63 | */ | |
b40a2cb6 MH |
64 | static int notifier_call_chain(struct notifier_block **nl, |
65 | unsigned long val, void *v, | |
66 | int nr_to_call, int *nr_calls) | |
fe9d4f57 AD |
67 | { |
68 | int ret = NOTIFY_DONE; | |
69 | struct notifier_block *nb, *next_nb; | |
70 | ||
d11c563d | 71 | nb = rcu_dereference_raw(*nl); |
fe9d4f57 AD |
72 | |
73 | while (nb && nr_to_call) { | |
d11c563d | 74 | next_nb = rcu_dereference_raw(nb->next); |
1b2439db AV |
75 | |
76 | #ifdef CONFIG_DEBUG_NOTIFIERS | |
ab7476cf | 77 | if (unlikely(!func_ptr_is_kernel_text(nb->notifier_call))) { |
1b2439db AV |
78 | WARN(1, "Invalid notifier called!"); |
79 | nb = next_nb; | |
80 | continue; | |
81 | } | |
82 | #endif | |
fe9d4f57 AD |
83 | ret = nb->notifier_call(nb, val, v); |
84 | ||
85 | if (nr_calls) | |
86 | (*nr_calls)++; | |
87 | ||
3e6daded | 88 | if (ret & NOTIFY_STOP_MASK) |
fe9d4f57 AD |
89 | break; |
90 | nb = next_nb; | |
91 | nr_to_call--; | |
92 | } | |
93 | return ret; | |
94 | } | |
b40a2cb6 | 95 | NOKPROBE_SYMBOL(notifier_call_chain); |
fe9d4f57 | 96 | |
70d93298 PZ |
97 | /** |
98 | * notifier_call_chain_robust - Inform the registered notifiers about an event | |
99 | * and rollback on error. | |
100 | * @nl: Pointer to head of the blocking notifier chain | |
101 | * @val_up: Value passed unmodified to the notifier function | |
102 | * @val_down: Value passed unmodified to the notifier function when recovering | |
103 | * from an error on @val_up | |
104 | * @v Pointer passed unmodified to the notifier function | |
105 | * | |
106 | * NOTE: It is important the @nl chain doesn't change between the two | |
107 | * invocations of notifier_call_chain() such that we visit the | |
108 | * exact same notifier callbacks; this rules out any RCU usage. | |
109 | * | |
110 | * Returns: the return value of the @val_up call. | |
111 | */ | |
112 | static int notifier_call_chain_robust(struct notifier_block **nl, | |
113 | unsigned long val_up, unsigned long val_down, | |
114 | void *v) | |
115 | { | |
116 | int ret, nr = 0; | |
117 | ||
118 | ret = notifier_call_chain(nl, val_up, v, -1, &nr); | |
119 | if (ret & NOTIFY_STOP_MASK) | |
120 | notifier_call_chain(nl, val_down, v, nr-1, NULL); | |
121 | ||
122 | return ret; | |
123 | } | |
124 | ||
fe9d4f57 AD |
125 | /* |
126 | * Atomic notifier chain routines. Registration and unregistration | |
127 | * use a spinlock, and call_chain is synchronized by RCU (no locks). | |
128 | */ | |
129 | ||
130 | /** | |
131 | * atomic_notifier_chain_register - Add notifier to an atomic notifier chain | |
132 | * @nh: Pointer to head of the atomic notifier chain | |
133 | * @n: New entry in notifier chain | |
134 | * | |
135 | * Adds a notifier to an atomic notifier chain. | |
136 | * | |
137 | * Currently always returns zero. | |
138 | */ | |
139 | int atomic_notifier_chain_register(struct atomic_notifier_head *nh, | |
140 | struct notifier_block *n) | |
141 | { | |
142 | unsigned long flags; | |
143 | int ret; | |
144 | ||
145 | spin_lock_irqsave(&nh->lock, flags); | |
146 | ret = notifier_chain_register(&nh->head, n); | |
147 | spin_unlock_irqrestore(&nh->lock, flags); | |
148 | return ret; | |
149 | } | |
150 | EXPORT_SYMBOL_GPL(atomic_notifier_chain_register); | |
151 | ||
152 | /** | |
153 | * atomic_notifier_chain_unregister - Remove notifier from an atomic notifier chain | |
154 | * @nh: Pointer to head of the atomic notifier chain | |
155 | * @n: Entry to remove from notifier chain | |
156 | * | |
157 | * Removes a notifier from an atomic notifier chain. | |
158 | * | |
159 | * Returns zero on success or %-ENOENT on failure. | |
160 | */ | |
161 | int atomic_notifier_chain_unregister(struct atomic_notifier_head *nh, | |
162 | struct notifier_block *n) | |
163 | { | |
164 | unsigned long flags; | |
165 | int ret; | |
166 | ||
167 | spin_lock_irqsave(&nh->lock, flags); | |
168 | ret = notifier_chain_unregister(&nh->head, n); | |
169 | spin_unlock_irqrestore(&nh->lock, flags); | |
170 | synchronize_rcu(); | |
171 | return ret; | |
172 | } | |
173 | EXPORT_SYMBOL_GPL(atomic_notifier_chain_unregister); | |
174 | ||
70d93298 PZ |
175 | int atomic_notifier_call_chain_robust(struct atomic_notifier_head *nh, |
176 | unsigned long val_up, unsigned long val_down, void *v) | |
177 | { | |
178 | unsigned long flags; | |
179 | int ret; | |
180 | ||
181 | /* | |
182 | * Musn't use RCU; because then the notifier list can | |
183 | * change between the up and down traversal. | |
184 | */ | |
185 | spin_lock_irqsave(&nh->lock, flags); | |
186 | ret = notifier_call_chain_robust(&nh->head, val_up, val_down, v); | |
187 | spin_unlock_irqrestore(&nh->lock, flags); | |
188 | ||
189 | return ret; | |
190 | } | |
191 | EXPORT_SYMBOL_GPL(atomic_notifier_call_chain_robust); | |
192 | NOKPROBE_SYMBOL(atomic_notifier_call_chain_robust); | |
193 | ||
fe9d4f57 | 194 | /** |
70d93298 | 195 | * atomic_notifier_call_chain - Call functions in an atomic notifier chain |
fe9d4f57 AD |
196 | * @nh: Pointer to head of the atomic notifier chain |
197 | * @val: Value passed unmodified to notifier function | |
198 | * @v: Pointer passed unmodified to notifier function | |
fe9d4f57 AD |
199 | * |
200 | * Calls each function in a notifier chain in turn. The functions | |
201 | * run in an atomic context, so they must not block. | |
202 | * This routine uses RCU to synchronize with changes to the chain. | |
203 | * | |
204 | * If the return value of the notifier can be and'ed | |
205 | * with %NOTIFY_STOP_MASK then atomic_notifier_call_chain() | |
206 | * will return immediately, with the return value of | |
207 | * the notifier function which halted execution. | |
208 | * Otherwise the return value is the return value | |
209 | * of the last notifier function called. | |
210 | */ | |
70d93298 PZ |
211 | int atomic_notifier_call_chain(struct atomic_notifier_head *nh, |
212 | unsigned long val, void *v) | |
fe9d4f57 AD |
213 | { |
214 | int ret; | |
215 | ||
216 | rcu_read_lock(); | |
70d93298 | 217 | ret = notifier_call_chain(&nh->head, val, v, -1, NULL); |
fe9d4f57 | 218 | rcu_read_unlock(); |
fe9d4f57 | 219 | |
70d93298 | 220 | return ret; |
fe9d4f57 AD |
221 | } |
222 | EXPORT_SYMBOL_GPL(atomic_notifier_call_chain); | |
b40a2cb6 | 223 | NOKPROBE_SYMBOL(atomic_notifier_call_chain); |
fe9d4f57 AD |
224 | |
225 | /* | |
226 | * Blocking notifier chain routines. All access to the chain is | |
227 | * synchronized by an rwsem. | |
228 | */ | |
229 | ||
230 | /** | |
231 | * blocking_notifier_chain_register - Add notifier to a blocking notifier chain | |
232 | * @nh: Pointer to head of the blocking notifier chain | |
233 | * @n: New entry in notifier chain | |
234 | * | |
235 | * Adds a notifier to a blocking notifier chain. | |
236 | * Must be called in process context. | |
237 | * | |
238 | * Currently always returns zero. | |
239 | */ | |
240 | int blocking_notifier_chain_register(struct blocking_notifier_head *nh, | |
241 | struct notifier_block *n) | |
242 | { | |
243 | int ret; | |
244 | ||
245 | /* | |
246 | * This code gets used during boot-up, when task switching is | |
247 | * not yet working and interrupts must remain disabled. At | |
248 | * such times we must not call down_write(). | |
249 | */ | |
250 | if (unlikely(system_state == SYSTEM_BOOTING)) | |
251 | return notifier_chain_register(&nh->head, n); | |
252 | ||
253 | down_write(&nh->rwsem); | |
254 | ret = notifier_chain_register(&nh->head, n); | |
255 | up_write(&nh->rwsem); | |
256 | return ret; | |
257 | } | |
258 | EXPORT_SYMBOL_GPL(blocking_notifier_chain_register); | |
259 | ||
260 | /** | |
261 | * blocking_notifier_chain_unregister - Remove notifier from a blocking notifier chain | |
262 | * @nh: Pointer to head of the blocking notifier chain | |
263 | * @n: Entry to remove from notifier chain | |
264 | * | |
265 | * Removes a notifier from a blocking notifier chain. | |
266 | * Must be called from process context. | |
267 | * | |
268 | * Returns zero on success or %-ENOENT on failure. | |
269 | */ | |
270 | int blocking_notifier_chain_unregister(struct blocking_notifier_head *nh, | |
271 | struct notifier_block *n) | |
272 | { | |
273 | int ret; | |
274 | ||
275 | /* | |
276 | * This code gets used during boot-up, when task switching is | |
277 | * not yet working and interrupts must remain disabled. At | |
278 | * such times we must not call down_write(). | |
279 | */ | |
280 | if (unlikely(system_state == SYSTEM_BOOTING)) | |
281 | return notifier_chain_unregister(&nh->head, n); | |
282 | ||
283 | down_write(&nh->rwsem); | |
284 | ret = notifier_chain_unregister(&nh->head, n); | |
285 | up_write(&nh->rwsem); | |
286 | return ret; | |
287 | } | |
288 | EXPORT_SYMBOL_GPL(blocking_notifier_chain_unregister); | |
289 | ||
70d93298 PZ |
290 | int blocking_notifier_call_chain_robust(struct blocking_notifier_head *nh, |
291 | unsigned long val_up, unsigned long val_down, void *v) | |
292 | { | |
293 | int ret = NOTIFY_DONE; | |
294 | ||
295 | /* | |
296 | * We check the head outside the lock, but if this access is | |
297 | * racy then it does not matter what the result of the test | |
298 | * is, we re-check the list after having taken the lock anyway: | |
299 | */ | |
300 | if (rcu_access_pointer(nh->head)) { | |
301 | down_read(&nh->rwsem); | |
302 | ret = notifier_call_chain_robust(&nh->head, val_up, val_down, v); | |
303 | up_read(&nh->rwsem); | |
304 | } | |
305 | return ret; | |
306 | } | |
307 | EXPORT_SYMBOL_GPL(blocking_notifier_call_chain_robust); | |
308 | ||
fe9d4f57 | 309 | /** |
70d93298 | 310 | * blocking_notifier_call_chain - Call functions in a blocking notifier chain |
fe9d4f57 AD |
311 | * @nh: Pointer to head of the blocking notifier chain |
312 | * @val: Value passed unmodified to notifier function | |
313 | * @v: Pointer passed unmodified to notifier function | |
fe9d4f57 AD |
314 | * |
315 | * Calls each function in a notifier chain in turn. The functions | |
316 | * run in a process context, so they are allowed to block. | |
317 | * | |
318 | * If the return value of the notifier can be and'ed | |
319 | * with %NOTIFY_STOP_MASK then blocking_notifier_call_chain() | |
320 | * will return immediately, with the return value of | |
321 | * the notifier function which halted execution. | |
322 | * Otherwise the return value is the return value | |
323 | * of the last notifier function called. | |
324 | */ | |
70d93298 PZ |
325 | int blocking_notifier_call_chain(struct blocking_notifier_head *nh, |
326 | unsigned long val, void *v) | |
fe9d4f57 AD |
327 | { |
328 | int ret = NOTIFY_DONE; | |
329 | ||
330 | /* | |
331 | * We check the head outside the lock, but if this access is | |
332 | * racy then it does not matter what the result of the test | |
333 | * is, we re-check the list after having taken the lock anyway: | |
334 | */ | |
8857563b | 335 | if (rcu_access_pointer(nh->head)) { |
fe9d4f57 | 336 | down_read(&nh->rwsem); |
70d93298 | 337 | ret = notifier_call_chain(&nh->head, val, v, -1, NULL); |
fe9d4f57 AD |
338 | up_read(&nh->rwsem); |
339 | } | |
340 | return ret; | |
341 | } | |
fe9d4f57 AD |
342 | EXPORT_SYMBOL_GPL(blocking_notifier_call_chain); |
343 | ||
344 | /* | |
345 | * Raw notifier chain routines. There is no protection; | |
346 | * the caller must provide it. Use at your own risk! | |
347 | */ | |
348 | ||
349 | /** | |
350 | * raw_notifier_chain_register - Add notifier to a raw notifier chain | |
351 | * @nh: Pointer to head of the raw notifier chain | |
352 | * @n: New entry in notifier chain | |
353 | * | |
354 | * Adds a notifier to a raw notifier chain. | |
355 | * All locking must be provided by the caller. | |
356 | * | |
357 | * Currently always returns zero. | |
358 | */ | |
359 | int raw_notifier_chain_register(struct raw_notifier_head *nh, | |
360 | struct notifier_block *n) | |
361 | { | |
362 | return notifier_chain_register(&nh->head, n); | |
363 | } | |
364 | EXPORT_SYMBOL_GPL(raw_notifier_chain_register); | |
365 | ||
366 | /** | |
367 | * raw_notifier_chain_unregister - Remove notifier from a raw notifier chain | |
368 | * @nh: Pointer to head of the raw notifier chain | |
369 | * @n: Entry to remove from notifier chain | |
370 | * | |
371 | * Removes a notifier from a raw notifier chain. | |
372 | * All locking must be provided by the caller. | |
373 | * | |
374 | * Returns zero on success or %-ENOENT on failure. | |
375 | */ | |
376 | int raw_notifier_chain_unregister(struct raw_notifier_head *nh, | |
377 | struct notifier_block *n) | |
378 | { | |
379 | return notifier_chain_unregister(&nh->head, n); | |
380 | } | |
381 | EXPORT_SYMBOL_GPL(raw_notifier_chain_unregister); | |
382 | ||
70d93298 PZ |
383 | int raw_notifier_call_chain_robust(struct raw_notifier_head *nh, |
384 | unsigned long val_up, unsigned long val_down, void *v) | |
385 | { | |
386 | return notifier_call_chain_robust(&nh->head, val_up, val_down, v); | |
387 | } | |
388 | EXPORT_SYMBOL_GPL(raw_notifier_call_chain_robust); | |
389 | ||
fe9d4f57 | 390 | /** |
70d93298 | 391 | * raw_notifier_call_chain - Call functions in a raw notifier chain |
fe9d4f57 AD |
392 | * @nh: Pointer to head of the raw notifier chain |
393 | * @val: Value passed unmodified to notifier function | |
394 | * @v: Pointer passed unmodified to notifier function | |
fe9d4f57 AD |
395 | * |
396 | * Calls each function in a notifier chain in turn. The functions | |
397 | * run in an undefined context. | |
398 | * All locking must be provided by the caller. | |
399 | * | |
400 | * If the return value of the notifier can be and'ed | |
401 | * with %NOTIFY_STOP_MASK then raw_notifier_call_chain() | |
402 | * will return immediately, with the return value of | |
403 | * the notifier function which halted execution. | |
404 | * Otherwise the return value is the return value | |
405 | * of the last notifier function called. | |
406 | */ | |
fe9d4f57 AD |
407 | int raw_notifier_call_chain(struct raw_notifier_head *nh, |
408 | unsigned long val, void *v) | |
409 | { | |
70d93298 | 410 | return notifier_call_chain(&nh->head, val, v, -1, NULL); |
fe9d4f57 AD |
411 | } |
412 | EXPORT_SYMBOL_GPL(raw_notifier_call_chain); | |
413 | ||
83fe27ea | 414 | #ifdef CONFIG_SRCU |
fe9d4f57 AD |
415 | /* |
416 | * SRCU notifier chain routines. Registration and unregistration | |
417 | * use a mutex, and call_chain is synchronized by SRCU (no locks). | |
418 | */ | |
419 | ||
420 | /** | |
421 | * srcu_notifier_chain_register - Add notifier to an SRCU notifier chain | |
422 | * @nh: Pointer to head of the SRCU notifier chain | |
423 | * @n: New entry in notifier chain | |
424 | * | |
425 | * Adds a notifier to an SRCU notifier chain. | |
426 | * Must be called in process context. | |
427 | * | |
428 | * Currently always returns zero. | |
429 | */ | |
430 | int srcu_notifier_chain_register(struct srcu_notifier_head *nh, | |
431 | struct notifier_block *n) | |
432 | { | |
433 | int ret; | |
434 | ||
435 | /* | |
436 | * This code gets used during boot-up, when task switching is | |
437 | * not yet working and interrupts must remain disabled. At | |
438 | * such times we must not call mutex_lock(). | |
439 | */ | |
440 | if (unlikely(system_state == SYSTEM_BOOTING)) | |
441 | return notifier_chain_register(&nh->head, n); | |
442 | ||
443 | mutex_lock(&nh->mutex); | |
444 | ret = notifier_chain_register(&nh->head, n); | |
445 | mutex_unlock(&nh->mutex); | |
446 | return ret; | |
447 | } | |
448 | EXPORT_SYMBOL_GPL(srcu_notifier_chain_register); | |
449 | ||
450 | /** | |
451 | * srcu_notifier_chain_unregister - Remove notifier from an SRCU notifier chain | |
452 | * @nh: Pointer to head of the SRCU notifier chain | |
453 | * @n: Entry to remove from notifier chain | |
454 | * | |
455 | * Removes a notifier from an SRCU notifier chain. | |
456 | * Must be called from process context. | |
457 | * | |
458 | * Returns zero on success or %-ENOENT on failure. | |
459 | */ | |
460 | int srcu_notifier_chain_unregister(struct srcu_notifier_head *nh, | |
461 | struct notifier_block *n) | |
462 | { | |
463 | int ret; | |
464 | ||
465 | /* | |
466 | * This code gets used during boot-up, when task switching is | |
467 | * not yet working and interrupts must remain disabled. At | |
468 | * such times we must not call mutex_lock(). | |
469 | */ | |
470 | if (unlikely(system_state == SYSTEM_BOOTING)) | |
471 | return notifier_chain_unregister(&nh->head, n); | |
472 | ||
473 | mutex_lock(&nh->mutex); | |
474 | ret = notifier_chain_unregister(&nh->head, n); | |
475 | mutex_unlock(&nh->mutex); | |
476 | synchronize_srcu(&nh->srcu); | |
477 | return ret; | |
478 | } | |
479 | EXPORT_SYMBOL_GPL(srcu_notifier_chain_unregister); | |
480 | ||
481 | /** | |
70d93298 | 482 | * srcu_notifier_call_chain - Call functions in an SRCU notifier chain |
fe9d4f57 AD |
483 | * @nh: Pointer to head of the SRCU notifier chain |
484 | * @val: Value passed unmodified to notifier function | |
485 | * @v: Pointer passed unmodified to notifier function | |
fe9d4f57 AD |
486 | * |
487 | * Calls each function in a notifier chain in turn. The functions | |
488 | * run in a process context, so they are allowed to block. | |
489 | * | |
490 | * If the return value of the notifier can be and'ed | |
491 | * with %NOTIFY_STOP_MASK then srcu_notifier_call_chain() | |
492 | * will return immediately, with the return value of | |
493 | * the notifier function which halted execution. | |
494 | * Otherwise the return value is the return value | |
495 | * of the last notifier function called. | |
496 | */ | |
70d93298 PZ |
497 | int srcu_notifier_call_chain(struct srcu_notifier_head *nh, |
498 | unsigned long val, void *v) | |
fe9d4f57 AD |
499 | { |
500 | int ret; | |
501 | int idx; | |
502 | ||
503 | idx = srcu_read_lock(&nh->srcu); | |
70d93298 | 504 | ret = notifier_call_chain(&nh->head, val, v, -1, NULL); |
fe9d4f57 AD |
505 | srcu_read_unlock(&nh->srcu, idx); |
506 | return ret; | |
507 | } | |
fe9d4f57 AD |
508 | EXPORT_SYMBOL_GPL(srcu_notifier_call_chain); |
509 | ||
510 | /** | |
511 | * srcu_init_notifier_head - Initialize an SRCU notifier head | |
512 | * @nh: Pointer to head of the srcu notifier chain | |
513 | * | |
514 | * Unlike other sorts of notifier heads, SRCU notifier heads require | |
515 | * dynamic initialization. Be sure to call this routine before | |
516 | * calling any of the other SRCU notifier routines for this head. | |
517 | * | |
518 | * If an SRCU notifier head is deallocated, it must first be cleaned | |
519 | * up by calling srcu_cleanup_notifier_head(). Otherwise the head's | |
520 | * per-cpu data (used by the SRCU mechanism) will leak. | |
521 | */ | |
522 | void srcu_init_notifier_head(struct srcu_notifier_head *nh) | |
523 | { | |
524 | mutex_init(&nh->mutex); | |
525 | if (init_srcu_struct(&nh->srcu) < 0) | |
526 | BUG(); | |
527 | nh->head = NULL; | |
528 | } | |
529 | EXPORT_SYMBOL_GPL(srcu_init_notifier_head); | |
530 | ||
83fe27ea PK |
531 | #endif /* CONFIG_SRCU */ |
532 | ||
fe9d4f57 AD |
533 | static ATOMIC_NOTIFIER_HEAD(die_chain); |
534 | ||
b40a2cb6 | 535 | int notrace notify_die(enum die_val val, const char *str, |
fe9d4f57 AD |
536 | struct pt_regs *regs, long err, int trap, int sig) |
537 | { | |
538 | struct die_args args = { | |
539 | .regs = regs, | |
540 | .str = str, | |
541 | .err = err, | |
542 | .trapnr = trap, | |
543 | .signr = sig, | |
544 | ||
545 | }; | |
5778077d | 546 | RCU_LOCKDEP_WARN(!rcu_is_watching(), |
e727c7d7 | 547 | "notify_die called but RCU thinks we're quiescent"); |
fe9d4f57 AD |
548 | return atomic_notifier_call_chain(&die_chain, val, &args); |
549 | } | |
b40a2cb6 | 550 | NOKPROBE_SYMBOL(notify_die); |
fe9d4f57 AD |
551 | |
552 | int register_die_notifier(struct notifier_block *nb) | |
553 | { | |
fe9d4f57 AD |
554 | return atomic_notifier_chain_register(&die_chain, nb); |
555 | } | |
556 | EXPORT_SYMBOL_GPL(register_die_notifier); | |
557 | ||
558 | int unregister_die_notifier(struct notifier_block *nb) | |
559 | { | |
560 | return atomic_notifier_chain_unregister(&die_chain, nb); | |
561 | } | |
562 | EXPORT_SYMBOL_GPL(unregister_die_notifier); |