Merge tag 'for-6.0-rc6-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave...
[platform/kernel/linux-starfive.git] / kernel / jump_label.c
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * jump label support
4  *
5  * Copyright (C) 2009 Jason Baron <jbaron@redhat.com>
6  * Copyright (C) 2011 Peter Zijlstra
7  *
8  */
9 #include <linux/memory.h>
10 #include <linux/uaccess.h>
11 #include <linux/module.h>
12 #include <linux/list.h>
13 #include <linux/slab.h>
14 #include <linux/sort.h>
15 #include <linux/err.h>
16 #include <linux/static_key.h>
17 #include <linux/jump_label_ratelimit.h>
18 #include <linux/bug.h>
19 #include <linux/cpu.h>
20 #include <asm/sections.h>
21
22 /* mutex to protect coming/going of the jump_label table */
23 static DEFINE_MUTEX(jump_label_mutex);
24
25 void jump_label_lock(void)
26 {
27         mutex_lock(&jump_label_mutex);
28 }
29
30 void jump_label_unlock(void)
31 {
32         mutex_unlock(&jump_label_mutex);
33 }
34
35 static int jump_label_cmp(const void *a, const void *b)
36 {
37         const struct jump_entry *jea = a;
38         const struct jump_entry *jeb = b;
39
40         /*
41          * Entrires are sorted by key.
42          */
43         if (jump_entry_key(jea) < jump_entry_key(jeb))
44                 return -1;
45
46         if (jump_entry_key(jea) > jump_entry_key(jeb))
47                 return 1;
48
49         /*
50          * In the batching mode, entries should also be sorted by the code
51          * inside the already sorted list of entries, enabling a bsearch in
52          * the vector.
53          */
54         if (jump_entry_code(jea) < jump_entry_code(jeb))
55                 return -1;
56
57         if (jump_entry_code(jea) > jump_entry_code(jeb))
58                 return 1;
59
60         return 0;
61 }
62
63 static void jump_label_swap(void *a, void *b, int size)
64 {
65         long delta = (unsigned long)a - (unsigned long)b;
66         struct jump_entry *jea = a;
67         struct jump_entry *jeb = b;
68         struct jump_entry tmp = *jea;
69
70         jea->code       = jeb->code - delta;
71         jea->target     = jeb->target - delta;
72         jea->key        = jeb->key - delta;
73
74         jeb->code       = tmp.code + delta;
75         jeb->target     = tmp.target + delta;
76         jeb->key        = tmp.key + delta;
77 }
78
79 static void
80 jump_label_sort_entries(struct jump_entry *start, struct jump_entry *stop)
81 {
82         unsigned long size;
83         void *swapfn = NULL;
84
85         if (IS_ENABLED(CONFIG_HAVE_ARCH_JUMP_LABEL_RELATIVE))
86                 swapfn = jump_label_swap;
87
88         size = (((unsigned long)stop - (unsigned long)start)
89                                         / sizeof(struct jump_entry));
90         sort(start, size, sizeof(struct jump_entry), jump_label_cmp, swapfn);
91 }
92
93 static void jump_label_update(struct static_key *key);
94
95 /*
96  * There are similar definitions for the !CONFIG_JUMP_LABEL case in jump_label.h.
97  * The use of 'atomic_read()' requires atomic.h and its problematic for some
98  * kernel headers such as kernel.h and others. Since static_key_count() is not
99  * used in the branch statements as it is for the !CONFIG_JUMP_LABEL case its ok
100  * to have it be a function here. Similarly, for 'static_key_enable()' and
101  * 'static_key_disable()', which require bug.h. This should allow jump_label.h
102  * to be included from most/all places for CONFIG_JUMP_LABEL.
103  */
104 int static_key_count(struct static_key *key)
105 {
106         /*
107          * -1 means the first static_key_slow_inc() is in progress.
108          *  static_key_enabled() must return true, so return 1 here.
109          */
110         int n = atomic_read(&key->enabled);
111
112         return n >= 0 ? n : 1;
113 }
114 EXPORT_SYMBOL_GPL(static_key_count);
115
116 void static_key_slow_inc_cpuslocked(struct static_key *key)
117 {
118         int v, v1;
119
120         STATIC_KEY_CHECK_USE(key);
121         lockdep_assert_cpus_held();
122
123         /*
124          * Careful if we get concurrent static_key_slow_inc() calls;
125          * later calls must wait for the first one to _finish_ the
126          * jump_label_update() process.  At the same time, however,
127          * the jump_label_update() call below wants to see
128          * static_key_enabled(&key) for jumps to be updated properly.
129          *
130          * So give a special meaning to negative key->enabled: it sends
131          * static_key_slow_inc() down the slow path, and it is non-zero
132          * so it counts as "enabled" in jump_label_update().  Note that
133          * atomic_inc_unless_negative() checks >= 0, so roll our own.
134          */
135         for (v = atomic_read(&key->enabled); v > 0; v = v1) {
136                 v1 = atomic_cmpxchg(&key->enabled, v, v + 1);
137                 if (likely(v1 == v))
138                         return;
139         }
140
141         jump_label_lock();
142         if (atomic_read(&key->enabled) == 0) {
143                 atomic_set(&key->enabled, -1);
144                 jump_label_update(key);
145                 /*
146                  * Ensure that if the above cmpxchg loop observes our positive
147                  * value, it must also observe all the text changes.
148                  */
149                 atomic_set_release(&key->enabled, 1);
150         } else {
151                 atomic_inc(&key->enabled);
152         }
153         jump_label_unlock();
154 }
155
156 void static_key_slow_inc(struct static_key *key)
157 {
158         cpus_read_lock();
159         static_key_slow_inc_cpuslocked(key);
160         cpus_read_unlock();
161 }
162 EXPORT_SYMBOL_GPL(static_key_slow_inc);
163
164 void static_key_enable_cpuslocked(struct static_key *key)
165 {
166         STATIC_KEY_CHECK_USE(key);
167         lockdep_assert_cpus_held();
168
169         if (atomic_read(&key->enabled) > 0) {
170                 WARN_ON_ONCE(atomic_read(&key->enabled) != 1);
171                 return;
172         }
173
174         jump_label_lock();
175         if (atomic_read(&key->enabled) == 0) {
176                 atomic_set(&key->enabled, -1);
177                 jump_label_update(key);
178                 /*
179                  * See static_key_slow_inc().
180                  */
181                 atomic_set_release(&key->enabled, 1);
182         }
183         jump_label_unlock();
184 }
185 EXPORT_SYMBOL_GPL(static_key_enable_cpuslocked);
186
187 void static_key_enable(struct static_key *key)
188 {
189         cpus_read_lock();
190         static_key_enable_cpuslocked(key);
191         cpus_read_unlock();
192 }
193 EXPORT_SYMBOL_GPL(static_key_enable);
194
195 void static_key_disable_cpuslocked(struct static_key *key)
196 {
197         STATIC_KEY_CHECK_USE(key);
198         lockdep_assert_cpus_held();
199
200         if (atomic_read(&key->enabled) != 1) {
201                 WARN_ON_ONCE(atomic_read(&key->enabled) != 0);
202                 return;
203         }
204
205         jump_label_lock();
206         if (atomic_cmpxchg(&key->enabled, 1, 0))
207                 jump_label_update(key);
208         jump_label_unlock();
209 }
210 EXPORT_SYMBOL_GPL(static_key_disable_cpuslocked);
211
212 void static_key_disable(struct static_key *key)
213 {
214         cpus_read_lock();
215         static_key_disable_cpuslocked(key);
216         cpus_read_unlock();
217 }
218 EXPORT_SYMBOL_GPL(static_key_disable);
219
220 static bool static_key_slow_try_dec(struct static_key *key)
221 {
222         int val;
223
224         val = atomic_fetch_add_unless(&key->enabled, -1, 1);
225         if (val == 1)
226                 return false;
227
228         /*
229          * The negative count check is valid even when a negative
230          * key->enabled is in use by static_key_slow_inc(); a
231          * __static_key_slow_dec() before the first static_key_slow_inc()
232          * returns is unbalanced, because all other static_key_slow_inc()
233          * instances block while the update is in progress.
234          */
235         WARN(val < 0, "jump label: negative count!\n");
236         return true;
237 }
238
239 static void __static_key_slow_dec_cpuslocked(struct static_key *key)
240 {
241         lockdep_assert_cpus_held();
242
243         if (static_key_slow_try_dec(key))
244                 return;
245
246         jump_label_lock();
247         if (atomic_dec_and_test(&key->enabled))
248                 jump_label_update(key);
249         jump_label_unlock();
250 }
251
252 static void __static_key_slow_dec(struct static_key *key)
253 {
254         cpus_read_lock();
255         __static_key_slow_dec_cpuslocked(key);
256         cpus_read_unlock();
257 }
258
259 void jump_label_update_timeout(struct work_struct *work)
260 {
261         struct static_key_deferred *key =
262                 container_of(work, struct static_key_deferred, work.work);
263         __static_key_slow_dec(&key->key);
264 }
265 EXPORT_SYMBOL_GPL(jump_label_update_timeout);
266
267 void static_key_slow_dec(struct static_key *key)
268 {
269         STATIC_KEY_CHECK_USE(key);
270         __static_key_slow_dec(key);
271 }
272 EXPORT_SYMBOL_GPL(static_key_slow_dec);
273
274 void static_key_slow_dec_cpuslocked(struct static_key *key)
275 {
276         STATIC_KEY_CHECK_USE(key);
277         __static_key_slow_dec_cpuslocked(key);
278 }
279
280 void __static_key_slow_dec_deferred(struct static_key *key,
281                                     struct delayed_work *work,
282                                     unsigned long timeout)
283 {
284         STATIC_KEY_CHECK_USE(key);
285
286         if (static_key_slow_try_dec(key))
287                 return;
288
289         schedule_delayed_work(work, timeout);
290 }
291 EXPORT_SYMBOL_GPL(__static_key_slow_dec_deferred);
292
293 void __static_key_deferred_flush(void *key, struct delayed_work *work)
294 {
295         STATIC_KEY_CHECK_USE(key);
296         flush_delayed_work(work);
297 }
298 EXPORT_SYMBOL_GPL(__static_key_deferred_flush);
299
300 void jump_label_rate_limit(struct static_key_deferred *key,
301                 unsigned long rl)
302 {
303         STATIC_KEY_CHECK_USE(key);
304         key->timeout = rl;
305         INIT_DELAYED_WORK(&key->work, jump_label_update_timeout);
306 }
307 EXPORT_SYMBOL_GPL(jump_label_rate_limit);
308
309 static int addr_conflict(struct jump_entry *entry, void *start, void *end)
310 {
311         if (jump_entry_code(entry) <= (unsigned long)end &&
312             jump_entry_code(entry) + jump_entry_size(entry) > (unsigned long)start)
313                 return 1;
314
315         return 0;
316 }
317
318 static int __jump_label_text_reserved(struct jump_entry *iter_start,
319                 struct jump_entry *iter_stop, void *start, void *end, bool init)
320 {
321         struct jump_entry *iter;
322
323         iter = iter_start;
324         while (iter < iter_stop) {
325                 if (init || !jump_entry_is_init(iter)) {
326                         if (addr_conflict(iter, start, end))
327                                 return 1;
328                 }
329                 iter++;
330         }
331
332         return 0;
333 }
334
335 #ifndef arch_jump_label_transform_static
336 static void arch_jump_label_transform_static(struct jump_entry *entry,
337                                              enum jump_label_type type)
338 {
339         /* nothing to do on most architectures */
340 }
341 #endif
342
343 static inline struct jump_entry *static_key_entries(struct static_key *key)
344 {
345         WARN_ON_ONCE(key->type & JUMP_TYPE_LINKED);
346         return (struct jump_entry *)(key->type & ~JUMP_TYPE_MASK);
347 }
348
349 static inline bool static_key_type(struct static_key *key)
350 {
351         return key->type & JUMP_TYPE_TRUE;
352 }
353
354 static inline bool static_key_linked(struct static_key *key)
355 {
356         return key->type & JUMP_TYPE_LINKED;
357 }
358
359 static inline void static_key_clear_linked(struct static_key *key)
360 {
361         key->type &= ~JUMP_TYPE_LINKED;
362 }
363
364 static inline void static_key_set_linked(struct static_key *key)
365 {
366         key->type |= JUMP_TYPE_LINKED;
367 }
368
369 /***
370  * A 'struct static_key' uses a union such that it either points directly
371  * to a table of 'struct jump_entry' or to a linked list of modules which in
372  * turn point to 'struct jump_entry' tables.
373  *
374  * The two lower bits of the pointer are used to keep track of which pointer
375  * type is in use and to store the initial branch direction, we use an access
376  * function which preserves these bits.
377  */
378 static void static_key_set_entries(struct static_key *key,
379                                    struct jump_entry *entries)
380 {
381         unsigned long type;
382
383         WARN_ON_ONCE((unsigned long)entries & JUMP_TYPE_MASK);
384         type = key->type & JUMP_TYPE_MASK;
385         key->entries = entries;
386         key->type |= type;
387 }
388
389 static enum jump_label_type jump_label_type(struct jump_entry *entry)
390 {
391         struct static_key *key = jump_entry_key(entry);
392         bool enabled = static_key_enabled(key);
393         bool branch = jump_entry_is_branch(entry);
394
395         /* See the comment in linux/jump_label.h */
396         return enabled ^ branch;
397 }
398
399 static bool jump_label_can_update(struct jump_entry *entry, bool init)
400 {
401         /*
402          * Cannot update code that was in an init text area.
403          */
404         if (!init && jump_entry_is_init(entry))
405                 return false;
406
407         if (!kernel_text_address(jump_entry_code(entry))) {
408                 /*
409                  * This skips patching built-in __exit, which
410                  * is part of init_section_contains() but is
411                  * not part of kernel_text_address().
412                  *
413                  * Skipping built-in __exit is fine since it
414                  * will never be executed.
415                  */
416                 WARN_ONCE(!jump_entry_is_init(entry),
417                           "can't patch jump_label at %pS",
418                           (void *)jump_entry_code(entry));
419                 return false;
420         }
421
422         return true;
423 }
424
425 #ifndef HAVE_JUMP_LABEL_BATCH
426 static void __jump_label_update(struct static_key *key,
427                                 struct jump_entry *entry,
428                                 struct jump_entry *stop,
429                                 bool init)
430 {
431         for (; (entry < stop) && (jump_entry_key(entry) == key); entry++) {
432                 if (jump_label_can_update(entry, init))
433                         arch_jump_label_transform(entry, jump_label_type(entry));
434         }
435 }
436 #else
437 static void __jump_label_update(struct static_key *key,
438                                 struct jump_entry *entry,
439                                 struct jump_entry *stop,
440                                 bool init)
441 {
442         for (; (entry < stop) && (jump_entry_key(entry) == key); entry++) {
443
444                 if (!jump_label_can_update(entry, init))
445                         continue;
446
447                 if (!arch_jump_label_transform_queue(entry, jump_label_type(entry))) {
448                         /*
449                          * Queue is full: Apply the current queue and try again.
450                          */
451                         arch_jump_label_transform_apply();
452                         BUG_ON(!arch_jump_label_transform_queue(entry, jump_label_type(entry)));
453                 }
454         }
455         arch_jump_label_transform_apply();
456 }
457 #endif
458
459 void __init jump_label_init(void)
460 {
461         struct jump_entry *iter_start = __start___jump_table;
462         struct jump_entry *iter_stop = __stop___jump_table;
463         struct static_key *key = NULL;
464         struct jump_entry *iter;
465
466         /*
467          * Since we are initializing the static_key.enabled field with
468          * with the 'raw' int values (to avoid pulling in atomic.h) in
469          * jump_label.h, let's make sure that is safe. There are only two
470          * cases to check since we initialize to 0 or 1.
471          */
472         BUILD_BUG_ON((int)ATOMIC_INIT(0) != 0);
473         BUILD_BUG_ON((int)ATOMIC_INIT(1) != 1);
474
475         if (static_key_initialized)
476                 return;
477
478         cpus_read_lock();
479         jump_label_lock();
480         jump_label_sort_entries(iter_start, iter_stop);
481
482         for (iter = iter_start; iter < iter_stop; iter++) {
483                 struct static_key *iterk;
484                 bool in_init;
485
486                 /* rewrite NOPs */
487                 if (jump_label_type(iter) == JUMP_LABEL_NOP)
488                         arch_jump_label_transform_static(iter, JUMP_LABEL_NOP);
489
490                 in_init = init_section_contains((void *)jump_entry_code(iter), 1);
491                 jump_entry_set_init(iter, in_init);
492
493                 iterk = jump_entry_key(iter);
494                 if (iterk == key)
495                         continue;
496
497                 key = iterk;
498                 static_key_set_entries(key, iter);
499         }
500         static_key_initialized = true;
501         jump_label_unlock();
502         cpus_read_unlock();
503 }
504
505 #ifdef CONFIG_MODULES
506
507 enum jump_label_type jump_label_init_type(struct jump_entry *entry)
508 {
509         struct static_key *key = jump_entry_key(entry);
510         bool type = static_key_type(key);
511         bool branch = jump_entry_is_branch(entry);
512
513         /* See the comment in linux/jump_label.h */
514         return type ^ branch;
515 }
516
517 struct static_key_mod {
518         struct static_key_mod *next;
519         struct jump_entry *entries;
520         struct module *mod;
521 };
522
523 static inline struct static_key_mod *static_key_mod(struct static_key *key)
524 {
525         WARN_ON_ONCE(!static_key_linked(key));
526         return (struct static_key_mod *)(key->type & ~JUMP_TYPE_MASK);
527 }
528
529 /***
530  * key->type and key->next are the same via union.
531  * This sets key->next and preserves the type bits.
532  *
533  * See additional comments above static_key_set_entries().
534  */
535 static void static_key_set_mod(struct static_key *key,
536                                struct static_key_mod *mod)
537 {
538         unsigned long type;
539
540         WARN_ON_ONCE((unsigned long)mod & JUMP_TYPE_MASK);
541         type = key->type & JUMP_TYPE_MASK;
542         key->next = mod;
543         key->type |= type;
544 }
545
546 static int __jump_label_mod_text_reserved(void *start, void *end)
547 {
548         struct module *mod;
549         int ret;
550
551         preempt_disable();
552         mod = __module_text_address((unsigned long)start);
553         WARN_ON_ONCE(__module_text_address((unsigned long)end) != mod);
554         if (!try_module_get(mod))
555                 mod = NULL;
556         preempt_enable();
557
558         if (!mod)
559                 return 0;
560
561         ret = __jump_label_text_reserved(mod->jump_entries,
562                                 mod->jump_entries + mod->num_jump_entries,
563                                 start, end, mod->state == MODULE_STATE_COMING);
564
565         module_put(mod);
566
567         return ret;
568 }
569
570 static void __jump_label_mod_update(struct static_key *key)
571 {
572         struct static_key_mod *mod;
573
574         for (mod = static_key_mod(key); mod; mod = mod->next) {
575                 struct jump_entry *stop;
576                 struct module *m;
577
578                 /*
579                  * NULL if the static_key is defined in a module
580                  * that does not use it
581                  */
582                 if (!mod->entries)
583                         continue;
584
585                 m = mod->mod;
586                 if (!m)
587                         stop = __stop___jump_table;
588                 else
589                         stop = m->jump_entries + m->num_jump_entries;
590                 __jump_label_update(key, mod->entries, stop,
591                                     m && m->state == MODULE_STATE_COMING);
592         }
593 }
594
595 static int jump_label_add_module(struct module *mod)
596 {
597         struct jump_entry *iter_start = mod->jump_entries;
598         struct jump_entry *iter_stop = iter_start + mod->num_jump_entries;
599         struct jump_entry *iter;
600         struct static_key *key = NULL;
601         struct static_key_mod *jlm, *jlm2;
602
603         /* if the module doesn't have jump label entries, just return */
604         if (iter_start == iter_stop)
605                 return 0;
606
607         jump_label_sort_entries(iter_start, iter_stop);
608
609         for (iter = iter_start; iter < iter_stop; iter++) {
610                 struct static_key *iterk;
611                 bool in_init;
612
613                 in_init = within_module_init(jump_entry_code(iter), mod);
614                 jump_entry_set_init(iter, in_init);
615
616                 iterk = jump_entry_key(iter);
617                 if (iterk == key)
618                         continue;
619
620                 key = iterk;
621                 if (within_module((unsigned long)key, mod)) {
622                         static_key_set_entries(key, iter);
623                         continue;
624                 }
625                 jlm = kzalloc(sizeof(struct static_key_mod), GFP_KERNEL);
626                 if (!jlm)
627                         return -ENOMEM;
628                 if (!static_key_linked(key)) {
629                         jlm2 = kzalloc(sizeof(struct static_key_mod),
630                                        GFP_KERNEL);
631                         if (!jlm2) {
632                                 kfree(jlm);
633                                 return -ENOMEM;
634                         }
635                         preempt_disable();
636                         jlm2->mod = __module_address((unsigned long)key);
637                         preempt_enable();
638                         jlm2->entries = static_key_entries(key);
639                         jlm2->next = NULL;
640                         static_key_set_mod(key, jlm2);
641                         static_key_set_linked(key);
642                 }
643                 jlm->mod = mod;
644                 jlm->entries = iter;
645                 jlm->next = static_key_mod(key);
646                 static_key_set_mod(key, jlm);
647                 static_key_set_linked(key);
648
649                 /* Only update if we've changed from our initial state */
650                 if (jump_label_type(iter) != jump_label_init_type(iter))
651                         __jump_label_update(key, iter, iter_stop, true);
652         }
653
654         return 0;
655 }
656
657 static void jump_label_del_module(struct module *mod)
658 {
659         struct jump_entry *iter_start = mod->jump_entries;
660         struct jump_entry *iter_stop = iter_start + mod->num_jump_entries;
661         struct jump_entry *iter;
662         struct static_key *key = NULL;
663         struct static_key_mod *jlm, **prev;
664
665         for (iter = iter_start; iter < iter_stop; iter++) {
666                 if (jump_entry_key(iter) == key)
667                         continue;
668
669                 key = jump_entry_key(iter);
670
671                 if (within_module((unsigned long)key, mod))
672                         continue;
673
674                 /* No memory during module load */
675                 if (WARN_ON(!static_key_linked(key)))
676                         continue;
677
678                 prev = &key->next;
679                 jlm = static_key_mod(key);
680
681                 while (jlm && jlm->mod != mod) {
682                         prev = &jlm->next;
683                         jlm = jlm->next;
684                 }
685
686                 /* No memory during module load */
687                 if (WARN_ON(!jlm))
688                         continue;
689
690                 if (prev == &key->next)
691                         static_key_set_mod(key, jlm->next);
692                 else
693                         *prev = jlm->next;
694
695                 kfree(jlm);
696
697                 jlm = static_key_mod(key);
698                 /* if only one etry is left, fold it back into the static_key */
699                 if (jlm->next == NULL) {
700                         static_key_set_entries(key, jlm->entries);
701                         static_key_clear_linked(key);
702                         kfree(jlm);
703                 }
704         }
705 }
706
707 static int
708 jump_label_module_notify(struct notifier_block *self, unsigned long val,
709                          void *data)
710 {
711         struct module *mod = data;
712         int ret = 0;
713
714         cpus_read_lock();
715         jump_label_lock();
716
717         switch (val) {
718         case MODULE_STATE_COMING:
719                 ret = jump_label_add_module(mod);
720                 if (ret) {
721                         WARN(1, "Failed to allocate memory: jump_label may not work properly.\n");
722                         jump_label_del_module(mod);
723                 }
724                 break;
725         case MODULE_STATE_GOING:
726                 jump_label_del_module(mod);
727                 break;
728         }
729
730         jump_label_unlock();
731         cpus_read_unlock();
732
733         return notifier_from_errno(ret);
734 }
735
736 static struct notifier_block jump_label_module_nb = {
737         .notifier_call = jump_label_module_notify,
738         .priority = 1, /* higher than tracepoints */
739 };
740
741 static __init int jump_label_init_module(void)
742 {
743         return register_module_notifier(&jump_label_module_nb);
744 }
745 early_initcall(jump_label_init_module);
746
747 #endif /* CONFIG_MODULES */
748
749 /***
750  * jump_label_text_reserved - check if addr range is reserved
751  * @start: start text addr
752  * @end: end text addr
753  *
754  * checks if the text addr located between @start and @end
755  * overlaps with any of the jump label patch addresses. Code
756  * that wants to modify kernel text should first verify that
757  * it does not overlap with any of the jump label addresses.
758  * Caller must hold jump_label_mutex.
759  *
760  * returns 1 if there is an overlap, 0 otherwise
761  */
762 int jump_label_text_reserved(void *start, void *end)
763 {
764         bool init = system_state < SYSTEM_RUNNING;
765         int ret = __jump_label_text_reserved(__start___jump_table,
766                         __stop___jump_table, start, end, init);
767
768         if (ret)
769                 return ret;
770
771 #ifdef CONFIG_MODULES
772         ret = __jump_label_mod_text_reserved(start, end);
773 #endif
774         return ret;
775 }
776
777 static void jump_label_update(struct static_key *key)
778 {
779         struct jump_entry *stop = __stop___jump_table;
780         bool init = system_state < SYSTEM_RUNNING;
781         struct jump_entry *entry;
782 #ifdef CONFIG_MODULES
783         struct module *mod;
784
785         if (static_key_linked(key)) {
786                 __jump_label_mod_update(key);
787                 return;
788         }
789
790         preempt_disable();
791         mod = __module_address((unsigned long)key);
792         if (mod) {
793                 stop = mod->jump_entries + mod->num_jump_entries;
794                 init = mod->state == MODULE_STATE_COMING;
795         }
796         preempt_enable();
797 #endif
798         entry = static_key_entries(key);
799         /* if there are no users, entry can be NULL */
800         if (entry)
801                 __jump_label_update(key, entry, stop, init);
802 }
803
804 #ifdef CONFIG_STATIC_KEYS_SELFTEST
805 static DEFINE_STATIC_KEY_TRUE(sk_true);
806 static DEFINE_STATIC_KEY_FALSE(sk_false);
807
808 static __init int jump_label_test(void)
809 {
810         int i;
811
812         for (i = 0; i < 2; i++) {
813                 WARN_ON(static_key_enabled(&sk_true.key) != true);
814                 WARN_ON(static_key_enabled(&sk_false.key) != false);
815
816                 WARN_ON(!static_branch_likely(&sk_true));
817                 WARN_ON(!static_branch_unlikely(&sk_true));
818                 WARN_ON(static_branch_likely(&sk_false));
819                 WARN_ON(static_branch_unlikely(&sk_false));
820
821                 static_branch_disable(&sk_true);
822                 static_branch_enable(&sk_false);
823
824                 WARN_ON(static_key_enabled(&sk_true.key) == true);
825                 WARN_ON(static_key_enabled(&sk_false.key) == false);
826
827                 WARN_ON(static_branch_likely(&sk_true));
828                 WARN_ON(static_branch_unlikely(&sk_true));
829                 WARN_ON(!static_branch_likely(&sk_false));
830                 WARN_ON(!static_branch_unlikely(&sk_false));
831
832                 static_branch_enable(&sk_true);
833                 static_branch_disable(&sk_false);
834         }
835
836         return 0;
837 }
838 early_initcall(jump_label_test);
839 #endif /* STATIC_KEYS_SELFTEST */