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 the jump_label table */
 23static DEFINE_MUTEX(jump_label_mutex);
 24
 25void jump_label_lock(void)
 26{
 27	mutex_lock(&jump_label_mutex);
 28}
 29
 30void jump_label_unlock(void)
 31{
 32	mutex_unlock(&jump_label_mutex);
 33}
 34
 
 
 
 
 
 35static 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
 63static 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
 79static void
 80jump_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
 93static 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 */
104int 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}
114EXPORT_SYMBOL_GPL(static_key_count);
115
116void 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
156void 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}
162EXPORT_SYMBOL_GPL(static_key_slow_inc);
163
164void 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}
185EXPORT_SYMBOL_GPL(static_key_enable_cpuslocked);
186
187void static_key_enable(struct static_key *key)
188{
189	cpus_read_lock();
190	static_key_enable_cpuslocked(key);
191	cpus_read_unlock();
192}
193EXPORT_SYMBOL_GPL(static_key_enable);
194
195void 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}
210EXPORT_SYMBOL_GPL(static_key_disable_cpuslocked);
211
212void static_key_disable(struct static_key *key)
213{
214	cpus_read_lock();
215	static_key_disable_cpuslocked(key);
216	cpus_read_unlock();
217}
218EXPORT_SYMBOL_GPL(static_key_disable);
219
220static 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
239static 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
252static 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
259void 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}
265EXPORT_SYMBOL_GPL(jump_label_update_timeout);
266
267void static_key_slow_dec(struct static_key *key)
268{
269	STATIC_KEY_CHECK_USE(key);
270	__static_key_slow_dec(key);
271}
272EXPORT_SYMBOL_GPL(static_key_slow_dec);
273
274void 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
280void __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}
291EXPORT_SYMBOL_GPL(__static_key_slow_dec_deferred);
292
293void __static_key_deferred_flush(void *key, struct delayed_work *work)
294{
295	STATIC_KEY_CHECK_USE(key);
296	flush_delayed_work(work);
297}
298EXPORT_SYMBOL_GPL(__static_key_deferred_flush);
299
300void 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}
307EXPORT_SYMBOL_GPL(jump_label_rate_limit);
308
309static 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_LABEL_NOP_SIZE > (unsigned long)start)
313		return 1;
314
315	return 0;
316}
317
318static int __jump_label_text_reserved(struct jump_entry *iter_start,
319		struct jump_entry *iter_stop, void *start, void *end)
320{
321	struct jump_entry *iter;
322
323	iter = iter_start;
324	while (iter < iter_stop) {
325		if (addr_conflict(iter, start, end))
326			return 1;
327		iter++;
328	}
329
330	return 0;
331}
332
333/*
334 * Update code which is definitely not currently executing.
335 * Architectures which need heavyweight synchronization to modify
336 * running code can override this to make the non-live update case
337 * cheaper.
338 */
339void __weak __init_or_module arch_jump_label_transform_static(struct jump_entry *entry,
340					    enum jump_label_type type)
341{
342	arch_jump_label_transform(entry, type);
343}
344
345static inline struct jump_entry *static_key_entries(struct static_key *key)
346{
347	WARN_ON_ONCE(key->type & JUMP_TYPE_LINKED);
348	return (struct jump_entry *)(key->type & ~JUMP_TYPE_MASK);
349}
350
351static inline bool static_key_type(struct static_key *key)
352{
353	return key->type & JUMP_TYPE_TRUE;
354}
355
356static inline bool static_key_linked(struct static_key *key)
357{
358	return key->type & JUMP_TYPE_LINKED;
359}
360
361static inline void static_key_clear_linked(struct static_key *key)
362{
363	key->type &= ~JUMP_TYPE_LINKED;
364}
365
366static inline void static_key_set_linked(struct static_key *key)
367{
368	key->type |= JUMP_TYPE_LINKED;
369}
370
371/***
372 * A 'struct static_key' uses a union such that it either points directly
373 * to a table of 'struct jump_entry' or to a linked list of modules which in
374 * turn point to 'struct jump_entry' tables.
375 *
376 * The two lower bits of the pointer are used to keep track of which pointer
377 * type is in use and to store the initial branch direction, we use an access
378 * function which preserves these bits.
379 */
380static void static_key_set_entries(struct static_key *key,
381				   struct jump_entry *entries)
382{
383	unsigned long type;
384
385	WARN_ON_ONCE((unsigned long)entries & JUMP_TYPE_MASK);
386	type = key->type & JUMP_TYPE_MASK;
387	key->entries = entries;
388	key->type |= type;
389}
390
391static enum jump_label_type jump_label_type(struct jump_entry *entry)
392{
393	struct static_key *key = jump_entry_key(entry);
394	bool enabled = static_key_enabled(key);
395	bool branch = jump_entry_is_branch(entry);
396
397	/* See the comment in linux/jump_label.h */
398	return enabled ^ branch;
399}
400
401static bool jump_label_can_update(struct jump_entry *entry, bool init)
402{
403	/*
404	 * Cannot update code that was in an init text area.
405	 */
406	if (!init && jump_entry_is_init(entry))
407		return false;
408
409	if (!kernel_text_address(jump_entry_code(entry))) {
410		WARN_ONCE(!jump_entry_is_init(entry),
411			  "can't patch jump_label at %pS",
412			  (void *)jump_entry_code(entry));
413		return false;
414	}
415
416	return true;
417}
418
419#ifndef HAVE_JUMP_LABEL_BATCH
420static void __jump_label_update(struct static_key *key,
421				struct jump_entry *entry,
422				struct jump_entry *stop,
423				bool init)
424{
425	for (; (entry < stop) && (jump_entry_key(entry) == key); entry++) {
426		if (jump_label_can_update(entry, init))
427			arch_jump_label_transform(entry, jump_label_type(entry));
 
 
 
 
 
 
 
428	}
429}
430#else
431static void __jump_label_update(struct static_key *key,
432				struct jump_entry *entry,
433				struct jump_entry *stop,
434				bool init)
435{
436	for (; (entry < stop) && (jump_entry_key(entry) == key); entry++) {
437
438		if (!jump_label_can_update(entry, init))
439			continue;
440
441		if (!arch_jump_label_transform_queue(entry, jump_label_type(entry))) {
442			/*
443			 * Queue is full: Apply the current queue and try again.
444			 */
445			arch_jump_label_transform_apply();
446			BUG_ON(!arch_jump_label_transform_queue(entry, jump_label_type(entry)));
447		}
448	}
449	arch_jump_label_transform_apply();
450}
451#endif
452
453void __init jump_label_init(void)
454{
455	struct jump_entry *iter_start = __start___jump_table;
456	struct jump_entry *iter_stop = __stop___jump_table;
457	struct static_key *key = NULL;
458	struct jump_entry *iter;
459
460	/*
461	 * Since we are initializing the static_key.enabled field with
462	 * with the 'raw' int values (to avoid pulling in atomic.h) in
463	 * jump_label.h, let's make sure that is safe. There are only two
464	 * cases to check since we initialize to 0 or 1.
465	 */
466	BUILD_BUG_ON((int)ATOMIC_INIT(0) != 0);
467	BUILD_BUG_ON((int)ATOMIC_INIT(1) != 1);
468
469	if (static_key_initialized)
470		return;
471
472	cpus_read_lock();
473	jump_label_lock();
474	jump_label_sort_entries(iter_start, iter_stop);
475
476	for (iter = iter_start; iter < iter_stop; iter++) {
477		struct static_key *iterk;
478
479		/* rewrite NOPs */
480		if (jump_label_type(iter) == JUMP_LABEL_NOP)
481			arch_jump_label_transform_static(iter, JUMP_LABEL_NOP);
482
483		if (init_section_contains((void *)jump_entry_code(iter), 1))
484			jump_entry_set_init(iter);
485
486		iterk = jump_entry_key(iter);
487		if (iterk == key)
488			continue;
489
490		key = iterk;
491		static_key_set_entries(key, iter);
 
 
 
 
492	}
493	static_key_initialized = true;
494	jump_label_unlock();
495	cpus_read_unlock();
 
496}
 
497
498#ifdef CONFIG_MODULES
499
500static enum jump_label_type jump_label_init_type(struct jump_entry *entry)
501{
502	struct static_key *key = jump_entry_key(entry);
503	bool type = static_key_type(key);
504	bool branch = jump_entry_is_branch(entry);
505
506	/* See the comment in linux/jump_label.h */
507	return type ^ branch;
508}
509
510struct static_key_mod {
511	struct static_key_mod *next;
512	struct jump_entry *entries;
513	struct module *mod;
514};
515
516static inline struct static_key_mod *static_key_mod(struct static_key *key)
517{
518	WARN_ON_ONCE(!static_key_linked(key));
519	return (struct static_key_mod *)(key->type & ~JUMP_TYPE_MASK);
520}
521
522/***
523 * key->type and key->next are the same via union.
524 * This sets key->next and preserves the type bits.
525 *
526 * See additional comments above static_key_set_entries().
527 */
528static void static_key_set_mod(struct static_key *key,
529			       struct static_key_mod *mod)
530{
531	unsigned long type;
532
533	WARN_ON_ONCE((unsigned long)mod & JUMP_TYPE_MASK);
534	type = key->type & JUMP_TYPE_MASK;
535	key->next = mod;
536	key->type |= type;
537}
538
539static int __jump_label_mod_text_reserved(void *start, void *end)
540{
541	struct module *mod;
542
543	preempt_disable();
544	mod = __module_text_address((unsigned long)start);
545	WARN_ON_ONCE(__module_text_address((unsigned long)end) != mod);
546	preempt_enable();
547
548	if (!mod)
549		return 0;
550
 
551
552	return __jump_label_text_reserved(mod->jump_entries,
553				mod->jump_entries + mod->num_jump_entries,
554				start, end);
555}
556
557static void __jump_label_mod_update(struct static_key *key)
558{
559	struct static_key_mod *mod;
560
561	for (mod = static_key_mod(key); mod; mod = mod->next) {
562		struct jump_entry *stop;
563		struct module *m;
564
565		/*
566		 * NULL if the static_key is defined in a module
567		 * that does not use it
568		 */
569		if (!mod->entries)
570			continue;
571
572		m = mod->mod;
573		if (!m)
574			stop = __stop___jump_table;
575		else
576			stop = m->jump_entries + m->num_jump_entries;
577		__jump_label_update(key, mod->entries, stop,
578				    m && m->state == MODULE_STATE_COMING);
579	}
580}
581
582/***
583 * apply_jump_label_nops - patch module jump labels with arch_get_jump_label_nop()
584 * @mod: module to patch
585 *
586 * Allow for run-time selection of the optimal nops. Before the module
587 * loads patch these with arch_get_jump_label_nop(), which is specified by
588 * the arch specific jump label code.
589 */
590void jump_label_apply_nops(struct module *mod)
591{
592	struct jump_entry *iter_start = mod->jump_entries;
593	struct jump_entry *iter_stop = iter_start + mod->num_jump_entries;
594	struct jump_entry *iter;
595
596	/* if the module doesn't have jump label entries, just return */
597	if (iter_start == iter_stop)
598		return;
599
600	for (iter = iter_start; iter < iter_stop; iter++) {
601		/* Only write NOPs for arch_branch_static(). */
602		if (jump_label_init_type(iter) == JUMP_LABEL_NOP)
603			arch_jump_label_transform_static(iter, JUMP_LABEL_NOP);
604	}
605}
606
607static int jump_label_add_module(struct module *mod)
608{
609	struct jump_entry *iter_start = mod->jump_entries;
610	struct jump_entry *iter_stop = iter_start + mod->num_jump_entries;
611	struct jump_entry *iter;
612	struct static_key *key = NULL;
613	struct static_key_mod *jlm, *jlm2;
614
615	/* if the module doesn't have jump label entries, just return */
616	if (iter_start == iter_stop)
617		return 0;
618
619	jump_label_sort_entries(iter_start, iter_stop);
620
621	for (iter = iter_start; iter < iter_stop; iter++) {
622		struct static_key *iterk;
623
624		if (within_module_init(jump_entry_code(iter), mod))
625			jump_entry_set_init(iter);
626
627		iterk = jump_entry_key(iter);
628		if (iterk == key)
629			continue;
630
631		key = iterk;
632		if (within_module((unsigned long)key, mod)) {
633			static_key_set_entries(key, iter);
 
 
 
634			continue;
635		}
636		jlm = kzalloc(sizeof(struct static_key_mod), GFP_KERNEL);
 
637		if (!jlm)
638			return -ENOMEM;
639		if (!static_key_linked(key)) {
640			jlm2 = kzalloc(sizeof(struct static_key_mod),
641				       GFP_KERNEL);
642			if (!jlm2) {
643				kfree(jlm);
644				return -ENOMEM;
645			}
646			preempt_disable();
647			jlm2->mod = __module_address((unsigned long)key);
648			preempt_enable();
649			jlm2->entries = static_key_entries(key);
650			jlm2->next = NULL;
651			static_key_set_mod(key, jlm2);
652			static_key_set_linked(key);
653		}
654		jlm->mod = mod;
655		jlm->entries = iter;
656		jlm->next = static_key_mod(key);
657		static_key_set_mod(key, jlm);
658		static_key_set_linked(key);
659
660		/* Only update if we've changed from our initial state */
661		if (jump_label_type(iter) != jump_label_init_type(iter))
662			__jump_label_update(key, iter, iter_stop, true);
663	}
664
665	return 0;
666}
667
668static void jump_label_del_module(struct module *mod)
669{
670	struct jump_entry *iter_start = mod->jump_entries;
671	struct jump_entry *iter_stop = iter_start + mod->num_jump_entries;
672	struct jump_entry *iter;
673	struct static_key *key = NULL;
674	struct static_key_mod *jlm, **prev;
675
676	for (iter = iter_start; iter < iter_stop; iter++) {
677		if (jump_entry_key(iter) == key)
678			continue;
679
680		key = jump_entry_key(iter);
681
682		if (within_module((unsigned long)key, mod))
683			continue;
684
685		/* No memory during module load */
686		if (WARN_ON(!static_key_linked(key)))
687			continue;
688
689		prev = &key->next;
690		jlm = static_key_mod(key);
691
692		while (jlm && jlm->mod != mod) {
693			prev = &jlm->next;
694			jlm = jlm->next;
695		}
696
697		/* No memory during module load */
698		if (WARN_ON(!jlm))
699			continue;
700
701		if (prev == &key->next)
702			static_key_set_mod(key, jlm->next);
703		else
704			*prev = jlm->next;
705
706		kfree(jlm);
707
708		jlm = static_key_mod(key);
709		/* if only one etry is left, fold it back into the static_key */
710		if (jlm->next == NULL) {
711			static_key_set_entries(key, jlm->entries);
712			static_key_clear_linked(key);
713			kfree(jlm);
714		}
715	}
716}
717
 
 
 
 
 
 
 
 
 
 
 
 
718static int
719jump_label_module_notify(struct notifier_block *self, unsigned long val,
720			 void *data)
721{
722	struct module *mod = data;
723	int ret = 0;
724
725	cpus_read_lock();
726	jump_label_lock();
727
728	switch (val) {
729	case MODULE_STATE_COMING:
 
730		ret = jump_label_add_module(mod);
731		if (ret) {
732			WARN(1, "Failed to allocate memory: jump_label may not work properly.\n");
733			jump_label_del_module(mod);
734		}
735		break;
736	case MODULE_STATE_GOING:
 
737		jump_label_del_module(mod);
 
 
 
 
 
 
738		break;
739	}
740
741	jump_label_unlock();
742	cpus_read_unlock();
743
744	return notifier_from_errno(ret);
745}
746
747static struct notifier_block jump_label_module_nb = {
748	.notifier_call = jump_label_module_notify,
749	.priority = 1, /* higher than tracepoints */
750};
751
752static __init int jump_label_init_module(void)
753{
754	return register_module_notifier(&jump_label_module_nb);
755}
756early_initcall(jump_label_init_module);
757
758#endif /* CONFIG_MODULES */
759
760/***
761 * jump_label_text_reserved - check if addr range is reserved
762 * @start: start text addr
763 * @end: end text addr
764 *
765 * checks if the text addr located between @start and @end
766 * overlaps with any of the jump label patch addresses. Code
767 * that wants to modify kernel text should first verify that
768 * it does not overlap with any of the jump label addresses.
769 * Caller must hold jump_label_mutex.
770 *
771 * returns 1 if there is an overlap, 0 otherwise
772 */
773int jump_label_text_reserved(void *start, void *end)
774{
775	int ret = __jump_label_text_reserved(__start___jump_table,
776			__stop___jump_table, start, end);
777
778	if (ret)
779		return ret;
780
781#ifdef CONFIG_MODULES
782	ret = __jump_label_mod_text_reserved(start, end);
783#endif
784	return ret;
785}
786
787static void jump_label_update(struct static_key *key)
788{
789	struct jump_entry *stop = __stop___jump_table;
790	struct jump_entry *entry;
791#ifdef CONFIG_MODULES
792	struct module *mod;
793
794	if (static_key_linked(key)) {
795		__jump_label_mod_update(key);
796		return;
797	}
798
799	preempt_disable();
800	mod = __module_address((unsigned long)key);
801	if (mod)
802		stop = mod->jump_entries + mod->num_jump_entries;
803	preempt_enable();
804#endif
805	entry = static_key_entries(key);
806	/* if there are no users, entry can be NULL */
807	if (entry)
808		__jump_label_update(key, entry, stop,
809				    system_state < SYSTEM_RUNNING);
810}
811
812#ifdef CONFIG_STATIC_KEYS_SELFTEST
813static DEFINE_STATIC_KEY_TRUE(sk_true);
814static DEFINE_STATIC_KEY_FALSE(sk_false);
815
816static __init int jump_label_test(void)
817{
818	int i;
819
820	for (i = 0; i < 2; i++) {
821		WARN_ON(static_key_enabled(&sk_true.key) != true);
822		WARN_ON(static_key_enabled(&sk_false.key) != false);
823
824		WARN_ON(!static_branch_likely(&sk_true));
825		WARN_ON(!static_branch_unlikely(&sk_true));
826		WARN_ON(static_branch_likely(&sk_false));
827		WARN_ON(static_branch_unlikely(&sk_false));
828
829		static_branch_disable(&sk_true);
830		static_branch_enable(&sk_false);
831
832		WARN_ON(static_key_enabled(&sk_true.key) == true);
833		WARN_ON(static_key_enabled(&sk_false.key) == false);
834
835		WARN_ON(static_branch_likely(&sk_true));
836		WARN_ON(static_branch_unlikely(&sk_true));
837		WARN_ON(!static_branch_likely(&sk_false));
838		WARN_ON(!static_branch_unlikely(&sk_false));
839
840		static_branch_enable(&sk_true);
841		static_branch_disable(&sk_false);
842	}
843
844	return 0;
845}
846early_initcall(jump_label_test);
847#endif /* STATIC_KEYS_SELFTEST */