[linux-2.6-block.git] / kernel / jump_label.c

/*
 * jump label support
 *
 * Copyright (C) 2009 Jason Baron <jbaron@redhat.com>
 * Copyright (C) 2011 Peter Zijlstra <pzijlstr@redhat.com>
 *
 */
#include <linux/memory.h>
#include <linux/uaccess.h>
#include <linux/module.h>
#include <linux/list.h>
#include <linux/slab.h>
#include <linux/sort.h>
#include <linux/err.h>
#include <linux/jump_label.h>

#ifdef HAVE_JUMP_LABEL

/* mutex to protect coming/going of the the jump_label table */
static DEFINE_MUTEX(jump_label_mutex);

void jump_label_lock(void)
{
	mutex_lock(&jump_label_mutex);
}

void jump_label_unlock(void)
{
	mutex_unlock(&jump_label_mutex);
}

bool jump_label_enabled(struct jump_label_key *key)
{
	return !!atomic_read(&key->enabled);
}

static int jump_label_cmp(const void *a, const void *b)
{
	const struct jump_entry *jea = a;
	const struct jump_entry *jeb = b;

	if (jea->key < jeb->key)
		return -1;

	if (jea->key > jeb->key)
		return 1;

	return 0;
}

static void
jump_label_sort_entries(struct jump_entry *start, struct jump_entry *stop)
{
	unsigned long size;

	size = (((unsigned long)stop - (unsigned long)start)
					/ sizeof(struct jump_entry));
	sort(start, size, sizeof(struct jump_entry), jump_label_cmp, NULL);
}

static void jump_label_update(struct jump_label_key *key, int enable);

void jump_label_inc(struct jump_label_key *key)
{
	if (atomic_inc_not_zero(&key->enabled))
		return;

	jump_label_lock();
	if (atomic_read(&key->enabled) == 0)
		jump_label_update(key, JUMP_LABEL_ENABLE);
	atomic_inc(&key->enabled);
	jump_label_unlock();
}

static void __jump_label_dec(struct jump_label_key *key,
		unsigned long rate_limit, struct delayed_work *work)
{
	if (!atomic_dec_and_mutex_lock(&key->enabled, &jump_label_mutex))
		return;

	if (rate_limit) {
		atomic_inc(&key->enabled);
		schedule_delayed_work(work, rate_limit);
	} else
		jump_label_update(key, JUMP_LABEL_DISABLE);

	jump_label_unlock();
}

static void jump_label_update_timeout(struct work_struct *work)
{
	struct jump_label_key_deferred *key =
		container_of(work, struct jump_label_key_deferred, work.work);
	__jump_label_dec(&key->key, 0, NULL);
}

void jump_label_dec(struct jump_label_key *key)
{
	__jump_label_dec(key, 0, NULL);
}

void jump_label_dec_deferred(struct jump_label_key_deferred *key)
{
	__jump_label_dec(&key->key, key->timeout, &key->work);
}


void jump_label_rate_limit(struct jump_label_key_deferred *key,
		unsigned long rl)
{
	key->timeout = rl;
	INIT_DELAYED_WORK(&key->work, jump_label_update_timeout);
}

static int addr_conflict(struct jump_entry *entry, void *start, void *end)
{
	if (entry->code <= (unsigned long)end &&
		entry->code + JUMP_LABEL_NOP_SIZE > (unsigned long)start)
		return 1;

	return 0;
}

static int __jump_label_text_reserved(struct jump_entry *iter_start,
		struct jump_entry *iter_stop, void *start, void *end)
{
	struct jump_entry *iter;

	iter = iter_start;
	while (iter < iter_stop) {
		if (addr_conflict(iter, start, end))
			return 1;
		iter++;
	}

	return 0;
}

/* 
 * Update code which is definitely not currently executing.
 * Architectures which need heavyweight synchronization to modify
 * running code can override this to make the non-live update case
 * cheaper.
 */
void __weak arch_jump_label_transform_static(struct jump_entry *entry,
					    enum jump_label_type type)
{
	arch_jump_label_transform(entry, type);	
}

static void __jump_label_update(struct jump_label_key *key,
				struct jump_entry *entry,
				struct jump_entry *stop, int enable)
{
	for (; (entry < stop) &&
	      (entry->key == (jump_label_t)(unsigned long)key);
	      entry++) {
		/*
		 * entry->code set to 0 invalidates module init text sections
		 * kernel_text_address() verifies we are not in core kernel
		 * init code, see jump_label_invalidate_module_init().
		 */
		if (entry->code && kernel_text_address(entry->code))
			arch_jump_label_transform(entry, enable);
	}
}

void __init jump_label_init(void)
{
	struct jump_entry *iter_start = __start___jump_table;
	struct jump_entry *iter_stop = __stop___jump_table;
	struct jump_label_key *key = NULL;
	struct jump_entry *iter;

	jump_label_lock();
	jump_label_sort_entries(iter_start, iter_stop);

	for (iter = iter_start; iter < iter_stop; iter++) {
		struct jump_label_key *iterk;

		iterk = (struct jump_label_key *)(unsigned long)iter->key;
		arch_jump_label_transform_static(iter, jump_label_enabled(iterk) ?
						 JUMP_LABEL_ENABLE : JUMP_LABEL_DISABLE);
		if (iterk == key)
			continue;

		key = iterk;
		key->entries = iter;
#ifdef CONFIG_MODULES
		key->next = NULL;
#endif
	}
	jump_label_unlock();
}

#ifdef CONFIG_MODULES

struct jump_label_mod {
	struct jump_label_mod *next;
	struct jump_entry *entries;
	struct module *mod;
};

static int __jump_label_mod_text_reserved(void *start, void *end)
{
	struct module *mod;

	mod = __module_text_address((unsigned long)start);
	if (!mod)
		return 0;

	WARN_ON_ONCE(__module_text_address((unsigned long)end) != mod);

	return __jump_label_text_reserved(mod->jump_entries,
				mod->jump_entries + mod->num_jump_entries,
				start, end);
}

static void __jump_label_mod_update(struct jump_label_key *key, int enable)
{
	struct jump_label_mod *mod = key->next;

	while (mod) {
		struct module *m = mod->mod;

		__jump_label_update(key, mod->entries,
				    m->jump_entries + m->num_jump_entries,
				    enable);
		mod = mod->next;
	}
}

/***
 * apply_jump_label_nops - patch module jump labels with arch_get_jump_label_nop()
 * @mod: module to patch
 *
 * Allow for run-time selection of the optimal nops. Before the module
 * loads patch these with arch_get_jump_label_nop(), which is specified by
 * the arch specific jump label code.
 */
void jump_label_apply_nops(struct module *mod)
{
	struct jump_entry *iter_start = mod->jump_entries;
	struct jump_entry *iter_stop = iter_start + mod->num_jump_entries;
	struct jump_entry *iter;

	/* if the module doesn't have jump label entries, just return */
	if (iter_start == iter_stop)
		return;

	for (iter = iter_start; iter < iter_stop; iter++)
		arch_jump_label_transform_static(iter, JUMP_LABEL_DISABLE);
}

static int jump_label_add_module(struct module *mod)
{
	struct jump_entry *iter_start = mod->jump_entries;
	struct jump_entry *iter_stop = iter_start + mod->num_jump_entries;
	struct jump_entry *iter;
	struct jump_label_key *key = NULL;
	struct jump_label_mod *jlm;

	/* if the module doesn't have jump label entries, just return */
	if (iter_start == iter_stop)
		return 0;

	jump_label_sort_entries(iter_start, iter_stop);

	for (iter = iter_start; iter < iter_stop; iter++) {
		if (iter->key == (jump_label_t)(unsigned long)key)
			continue;

		key = (struct jump_label_key *)(unsigned long)iter->key;

		if (__module_address(iter->key) == mod) {
			atomic_set(&key->enabled, 0);
			key->entries = iter;
			key->next = NULL;
			continue;
		}

		jlm = kzalloc(sizeof(struct jump_label_mod), GFP_KERNEL);
		if (!jlm)
			return -ENOMEM;

		jlm->mod = mod;
		jlm->entries = iter;
		jlm->next = key->next;
		key->next = jlm;

		if (jump_label_enabled(key))
			__jump_label_update(key, iter, iter_stop,
					    JUMP_LABEL_ENABLE);
	}

	return 0;
}

static void jump_label_del_module(struct module *mod)
{
	struct jump_entry *iter_start = mod->jump_entries;
	struct jump_entry *iter_stop = iter_start + mod->num_jump_entries;
	struct jump_entry *iter;
	struct jump_label_key *key = NULL;
	struct jump_label_mod *jlm, **prev;

	for (iter = iter_start; iter < iter_stop; iter++) {
		if (iter->key == (jump_label_t)(unsigned long)key)
			continue;

		key = (struct jump_label_key *)(unsigned long)iter->key;

		if (__module_address(iter->key) == mod)
			continue;

		prev = &key->next;
		jlm = key->next;

		while (jlm && jlm->mod != mod) {
			prev = &jlm->next;
			jlm = jlm->next;
		}

		if (jlm) {
			*prev = jlm->next;
			kfree(jlm);
		}
	}
}

static void jump_label_invalidate_module_init(struct module *mod)
{
	struct jump_entry *iter_start = mod->jump_entries;
	struct jump_entry *iter_stop = iter_start + mod->num_jump_entries;
	struct jump_entry *iter;

	for (iter = iter_start; iter < iter_stop; iter++) {
		if (within_module_init(iter->code, mod))
			iter->code = 0;
	}
}

static int
jump_label_module_notify(struct notifier_block *self, unsigned long val,
			 void *data)
{
	struct module *mod = data;
	int ret = 0;

	switch (val) {
	case MODULE_STATE_COMING:
		jump_label_lock();
		ret = jump_label_add_module(mod);
		if (ret)
			jump_label_del_module(mod);
		jump_label_unlock();
		break;
	case MODULE_STATE_GOING:
		jump_label_lock();
		jump_label_del_module(mod);
		jump_label_unlock();
		break;
	case MODULE_STATE_LIVE:
		jump_label_lock();
		jump_label_invalidate_module_init(mod);
		jump_label_unlock();
		break;
	}

	return notifier_from_errno(ret);
}

struct notifier_block jump_label_module_nb = {
	.notifier_call = jump_label_module_notify,
	.priority = 1, /* higher than tracepoints */
};

static __init int jump_label_init_module(void)
{
	return register_module_notifier(&jump_label_module_nb);
}
early_initcall(jump_label_init_module);

#endif /* CONFIG_MODULES */

/***
 * jump_label_text_reserved - check if addr range is reserved
 * @start: start text addr
 * @end: end text addr
 *
 * checks if the text addr located between @start and @end
 * overlaps with any of the jump label patch addresses. Code
 * that wants to modify kernel text should first verify that
 * it does not overlap with any of the jump label addresses.
 * Caller must hold jump_label_mutex.
 *
 * returns 1 if there is an overlap, 0 otherwise
 */
int jump_label_text_reserved(void *start, void *end)
{
	int ret = __jump_label_text_reserved(__start___jump_table,
			__stop___jump_table, start, end);

	if (ret)
		return ret;

#ifdef CONFIG_MODULES
	ret = __jump_label_mod_text_reserved(start, end);
#endif
	return ret;
}

static void jump_label_update(struct jump_label_key *key, int enable)
{
	struct jump_entry *entry = key->entries, *stop = __stop___jump_table;

#ifdef CONFIG_MODULES
	struct module *mod = __module_address((jump_label_t)key);

	__jump_label_mod_update(key, enable);

	if (mod)
		stop = mod->jump_entries + mod->num_jump_entries;
#endif
	/* if there are no users, entry can be NULL */
	if (entry)
		__jump_label_update(key, entry, stop, enable);
}

#endif
Commit	Line	Data
bf5438fc JB	1	/*
	2	* jump label support
	3	*
	4	* Copyright (C) 2009 Jason Baron <jbaron@redhat.com>
d430d3d7	5	* Copyright (C) 2011 Peter Zijlstra <pzijlstr@redhat.com>
bf5438fc JB	6	*
bf5438fc JB	7	*/
bf5438fc JB	8	#include <linux/memory.h>
	9	#include <linux/uaccess.h>
	10	#include <linux/module.h>
	11	#include <linux/list.h>
bf5438fc JB	12	#include <linux/slab.h>
	13	#include <linux/sort.h>
	14	#include <linux/err.h>
d430d3d7	15	#include <linux/jump_label.h>
bf5438fc JB	16
	17	#ifdef HAVE_JUMP_LABEL
	18
bf5438fc JB	19	/* mutex to protect coming/going of the the jump_label table */
	20	static DEFINE_MUTEX(jump_label_mutex);
	21
91bad2f8 JB	22	void jump_label_lock(void)
	23	{
	24	mutex_lock(&jump_label_mutex);
	25	}
	26
	27	void jump_label_unlock(void)
	28	{
	29	mutex_unlock(&jump_label_mutex);
	30	}
	31
d430d3d7 JB	32	bool jump_label_enabled(struct jump_label_key *key)
	33	{
	34	return !!atomic_read(&key->enabled);
	35	}
	36
bf5438fc JB	37	static int jump_label_cmp(const void a, const void b)
	38	{
	39	const struct jump_entry *jea = a;
	40	const struct jump_entry *jeb = b;
	41
	42	if (jea->key < jeb->key)
	43	return -1;
	44
	45	if (jea->key > jeb->key)
	46	return 1;
	47
	48	return 0;
	49	}
	50
	51	static void
d430d3d7	52	jump_label_sort_entries(struct jump_entry start, struct jump_entry stop)
bf5438fc JB	53	{
	54	unsigned long size;
	55
	56	size = (((unsigned long)stop - (unsigned long)start)
	57	/ sizeof(struct jump_entry));
	58	sort(start, size, sizeof(struct jump_entry), jump_label_cmp, NULL);
	59	}
	60
d430d3d7	61	static void jump_label_update(struct jump_label_key *key, int enable);
bf5438fc	62
d430d3d7	63	void jump_label_inc(struct jump_label_key *key)
bf5438fc	64	{
d430d3d7 JB	65	if (atomic_inc_not_zero(&key->enabled))
d430d3d7 JB	66	return;
bf5438fc	67
d430d3d7	68	jump_label_lock();
c8452afb	69	if (atomic_read(&key->enabled) == 0)
d430d3d7	70	jump_label_update(key, JUMP_LABEL_ENABLE);
c8452afb	71	atomic_inc(&key->enabled);
d430d3d7	72	jump_label_unlock();
bf5438fc JB	73	}
bf5438fc JB	74
b2029520 GN	75	static void __jump_label_dec(struct jump_label_key *key,
b2029520 GN	76	unsigned long rate_limit, struct delayed_work *work)
bf5438fc	77	{
d430d3d7 JB	78	if (!atomic_dec_and_mutex_lock(&key->enabled, &jump_label_mutex))
d430d3d7 JB	79	return;
bf5438fc	80
b2029520 GN	81	if (rate_limit) {
	82	atomic_inc(&key->enabled);
	83	schedule_delayed_work(work, rate_limit);
	84	} else
	85	jump_label_update(key, JUMP_LABEL_DISABLE);
	86
91bad2f8	87	jump_label_unlock();
bf5438fc JB	88	}
bf5438fc JB	89
b2029520 GN	90	static void jump_label_update_timeout(struct work_struct *work)
	91	{
	92	struct jump_label_key_deferred *key =
	93	container_of(work, struct jump_label_key_deferred, work.work);
	94	__jump_label_dec(&key->key, 0, NULL);
	95	}
	96
	97	void jump_label_dec(struct jump_label_key *key)
	98	{
	99	__jump_label_dec(key, 0, NULL);
	100	}
	101
	102	void jump_label_dec_deferred(struct jump_label_key_deferred *key)
	103	{
	104	__jump_label_dec(&key->key, key->timeout, &key->work);
	105	}
	106
	107
	108	void jump_label_rate_limit(struct jump_label_key_deferred *key,
	109	unsigned long rl)
	110	{
	111	key->timeout = rl;
	112	INIT_DELAYED_WORK(&key->work, jump_label_update_timeout);
	113	}
	114
4c3ef6d7 JB	115	static int addr_conflict(struct jump_entry entry, void start, void *end)
	116	{
	117	if (entry->code <= (unsigned long)end &&
	118	entry->code + JUMP_LABEL_NOP_SIZE > (unsigned long)start)
	119	return 1;
	120
	121	return 0;
	122	}
	123
d430d3d7 JB	124	static int __jump_label_text_reserved(struct jump_entry *iter_start,
d430d3d7 JB	125	struct jump_entry iter_stop, void start, void *end)
4c3ef6d7	126	{
4c3ef6d7	127	struct jump_entry *iter;
4c3ef6d7	128
4c3ef6d7 JB	129	iter = iter_start;
4c3ef6d7 JB	130	while (iter < iter_stop) {
d430d3d7 JB	131	if (addr_conflict(iter, start, end))
d430d3d7 JB	132	return 1;
4c3ef6d7 JB	133	iter++;
	134	}
	135
d430d3d7 JB	136	return 0;
	137	}
	138
20284aa7 JF	139	/*
	140	* Update code which is definitely not currently executing.
	141	* Architectures which need heavyweight synchronization to modify
	142	* running code can override this to make the non-live update case
	143	* cheaper.
	144	*/
	145	void __weak arch_jump_label_transform_static(struct jump_entry *entry,
	146	enum jump_label_type type)
	147	{
	148	arch_jump_label_transform(entry, type);
	149	}
	150
d430d3d7	151	static void __jump_label_update(struct jump_label_key *key,
7cbc5b8d JO	152	struct jump_entry *entry,
7cbc5b8d JO	153	struct jump_entry *stop, int enable)
d430d3d7	154	{
7cbc5b8d JO	155	for (; (entry < stop) &&
	156	(entry->key == (jump_label_t)(unsigned long)key);
	157	entry++) {
d430d3d7 JB	158	/*
	159	* entry->code set to 0 invalidates module init text sections
	160	* kernel_text_address() verifies we are not in core kernel
	161	* init code, see jump_label_invalidate_module_init().
	162	*/
	163	if (entry->code && kernel_text_address(entry->code))
	164	arch_jump_label_transform(entry, enable);
	165	}
4c3ef6d7 JB	166	}
4c3ef6d7 JB	167
97ce2c88	168	void __init jump_label_init(void)
bf5438fc	169	{
bf5438fc JB	170	struct jump_entry *iter_start = __start___jump_table;
bf5438fc JB	171	struct jump_entry *iter_stop = __stop___jump_table;
d430d3d7	172	struct jump_label_key *key = NULL;
bf5438fc JB	173	struct jump_entry *iter;
bf5438fc JB	174
91bad2f8	175	jump_label_lock();
d430d3d7 JB	176	jump_label_sort_entries(iter_start, iter_stop);
	177
	178	for (iter = iter_start; iter < iter_stop; iter++) {
37348804 JF	179	struct jump_label_key *iterk;
	180
	181	iterk = (struct jump_label_key *)(unsigned long)iter->key;
20284aa7 JF	182	arch_jump_label_transform_static(iter, jump_label_enabled(iterk) ?
20284aa7 JF	183	JUMP_LABEL_ENABLE : JUMP_LABEL_DISABLE);
37348804	184	if (iterk == key)
d430d3d7 JB	185	continue;
d430d3d7 JB	186
37348804	187	key = iterk;
d430d3d7 JB	188	key->entries = iter;
	189	#ifdef CONFIG_MODULES
	190	key->next = NULL;
	191	#endif
bf5438fc	192	}
91bad2f8	193	jump_label_unlock();
bf5438fc	194	}
bf5438fc JB	195
	196	#ifdef CONFIG_MODULES
	197
d430d3d7 JB	198	struct jump_label_mod {
	199	struct jump_label_mod *next;
	200	struct jump_entry *entries;
	201	struct module *mod;
	202	};
	203
	204	static int __jump_label_mod_text_reserved(void start, void end)
	205	{
	206	struct module *mod;
	207
	208	mod = __module_text_address((unsigned long)start);
	209	if (!mod)
	210	return 0;
	211
	212	WARN_ON_ONCE(__module_text_address((unsigned long)end) != mod);
	213
	214	return __jump_label_text_reserved(mod->jump_entries,
	215	mod->jump_entries + mod->num_jump_entries,
	216	start, end);
	217	}
	218
	219	static void __jump_label_mod_update(struct jump_label_key *key, int enable)
	220	{
	221	struct jump_label_mod *mod = key->next;
	222
	223	while (mod) {
7cbc5b8d JO	224	struct module *m = mod->mod;
	225
	226	__jump_label_update(key, mod->entries,
	227	m->jump_entries + m->num_jump_entries,
	228	enable);
d430d3d7 JB	229	mod = mod->next;
	230	}
	231	}
	232
	233	/***
	234	* apply_jump_label_nops - patch module jump labels with arch_get_jump_label_nop()
	235	* @mod: module to patch
	236	*
	237	* Allow for run-time selection of the optimal nops. Before the module
	238	* loads patch these with arch_get_jump_label_nop(), which is specified by
	239	* the arch specific jump label code.
	240	*/
	241	void jump_label_apply_nops(struct module *mod)
bf5438fc	242	{
d430d3d7 JB	243	struct jump_entry *iter_start = mod->jump_entries;
	244	struct jump_entry *iter_stop = iter_start + mod->num_jump_entries;
	245	struct jump_entry *iter;
	246
	247	/* if the module doesn't have jump label entries, just return */
	248	if (iter_start == iter_stop)
	249	return;
	250
	251	for (iter = iter_start; iter < iter_stop; iter++)
20284aa7	252	arch_jump_label_transform_static(iter, JUMP_LABEL_DISABLE);
bf5438fc JB	253	}
bf5438fc JB	254
d430d3d7	255	static int jump_label_add_module(struct module *mod)
bf5438fc	256	{
d430d3d7 JB	257	struct jump_entry *iter_start = mod->jump_entries;
	258	struct jump_entry *iter_stop = iter_start + mod->num_jump_entries;
	259	struct jump_entry *iter;
	260	struct jump_label_key *key = NULL;
	261	struct jump_label_mod *jlm;
bf5438fc JB	262
bf5438fc JB	263	/* if the module doesn't have jump label entries, just return */
d430d3d7	264	if (iter_start == iter_stop)
bf5438fc JB	265	return 0;
bf5438fc JB	266
d430d3d7 JB	267	jump_label_sort_entries(iter_start, iter_stop);
	268
	269	for (iter = iter_start; iter < iter_stop; iter++) {
	270	if (iter->key == (jump_label_t)(unsigned long)key)
	271	continue;
	272
	273	key = (struct jump_label_key *)(unsigned long)iter->key;
	274
	275	if (__module_address(iter->key) == mod) {
	276	atomic_set(&key->enabled, 0);
	277	key->entries = iter;
	278	key->next = NULL;
	279	continue;
bf5438fc	280	}
d430d3d7 JB	281
	282	jlm = kzalloc(sizeof(struct jump_label_mod), GFP_KERNEL);
	283	if (!jlm)
	284	return -ENOMEM;
	285
	286	jlm->mod = mod;
	287	jlm->entries = iter;
	288	jlm->next = key->next;
	289	key->next = jlm;
	290
	291	if (jump_label_enabled(key))
7cbc5b8d JO	292	__jump_label_update(key, iter, iter_stop,
7cbc5b8d JO	293	JUMP_LABEL_ENABLE);
bf5438fc	294	}
d430d3d7	295
bf5438fc JB	296	return 0;
	297	}
	298
d430d3d7	299	static void jump_label_del_module(struct module *mod)
bf5438fc	300	{
d430d3d7 JB	301	struct jump_entry *iter_start = mod->jump_entries;
	302	struct jump_entry *iter_stop = iter_start + mod->num_jump_entries;
	303	struct jump_entry *iter;
	304	struct jump_label_key *key = NULL;
	305	struct jump_label_mod jlm, *prev;
bf5438fc	306
d430d3d7 JB	307	for (iter = iter_start; iter < iter_stop; iter++) {
	308	if (iter->key == (jump_label_t)(unsigned long)key)
	309	continue;
	310
	311	key = (struct jump_label_key *)(unsigned long)iter->key;
	312
	313	if (__module_address(iter->key) == mod)
	314	continue;
	315
	316	prev = &key->next;
	317	jlm = key->next;
bf5438fc	318
d430d3d7 JB	319	while (jlm && jlm->mod != mod) {
	320	prev = &jlm->next;
	321	jlm = jlm->next;
	322	}
	323
	324	if (jlm) {
	325	*prev = jlm->next;
	326	kfree(jlm);
bf5438fc JB	327	}
	328	}
	329	}
	330
d430d3d7	331	static void jump_label_invalidate_module_init(struct module *mod)
b842f8fa	332	{
d430d3d7 JB	333	struct jump_entry *iter_start = mod->jump_entries;
d430d3d7 JB	334	struct jump_entry *iter_stop = iter_start + mod->num_jump_entries;
b842f8fa	335	struct jump_entry *iter;
b842f8fa	336
d430d3d7 JB	337	for (iter = iter_start; iter < iter_stop; iter++) {
	338	if (within_module_init(iter->code, mod))
	339	iter->code = 0;
b842f8fa JB	340	}
	341	}
	342
bf5438fc JB	343	static int
	344	jump_label_module_notify(struct notifier_block *self, unsigned long val,
	345	void *data)
	346	{
	347	struct module *mod = data;
	348	int ret = 0;
	349
	350	switch (val) {
	351	case MODULE_STATE_COMING:
91bad2f8	352	jump_label_lock();
d430d3d7	353	ret = jump_label_add_module(mod);
bf5438fc	354	if (ret)
d430d3d7	355	jump_label_del_module(mod);
91bad2f8	356	jump_label_unlock();
bf5438fc JB	357	break;
bf5438fc JB	358	case MODULE_STATE_GOING:
91bad2f8	359	jump_label_lock();
d430d3d7	360	jump_label_del_module(mod);
91bad2f8	361	jump_label_unlock();
bf5438fc	362	break;
b842f8fa	363	case MODULE_STATE_LIVE:
91bad2f8	364	jump_label_lock();
d430d3d7	365	jump_label_invalidate_module_init(mod);
91bad2f8	366	jump_label_unlock();
b842f8fa	367	break;
bf5438fc	368	}
bf5438fc	369
d430d3d7	370	return notifier_from_errno(ret);
bf5438fc JB	371	}
	372
	373	struct notifier_block jump_label_module_nb = {
	374	.notifier_call = jump_label_module_notify,
d430d3d7	375	.priority = 1, /* higher than tracepoints */
bf5438fc JB	376	};
bf5438fc JB	377
d430d3d7	378	static __init int jump_label_init_module(void)
bf5438fc JB	379	{
	380	return register_module_notifier(&jump_label_module_nb);
	381	}
d430d3d7	382	early_initcall(jump_label_init_module);
bf5438fc JB	383
	384	#endif /* CONFIG_MODULES */
	385
d430d3d7 JB	386	/***
	387	* jump_label_text_reserved - check if addr range is reserved
	388	* @start: start text addr
	389	* @end: end text addr
	390	*
	391	* checks if the text addr located between @start and @end
	392	* overlaps with any of the jump label patch addresses. Code
	393	* that wants to modify kernel text should first verify that
	394	* it does not overlap with any of the jump label addresses.
	395	* Caller must hold jump_label_mutex.
	396	*
	397	* returns 1 if there is an overlap, 0 otherwise
	398	*/
	399	int jump_label_text_reserved(void start, void end)
	400	{
	401	int ret = __jump_label_text_reserved(__start___jump_table,
	402	__stop___jump_table, start, end);
	403
	404	if (ret)
	405	return ret;
	406
	407	#ifdef CONFIG_MODULES
	408	ret = __jump_label_mod_text_reserved(start, end);
	409	#endif
	410	return ret;
	411	}
	412
	413	static void jump_label_update(struct jump_label_key *key, int enable)
	414	{
140fe3b1	415	struct jump_entry entry = key->entries, stop = __stop___jump_table;
d430d3d7 JB	416
d430d3d7 JB	417	#ifdef CONFIG_MODULES
140fe3b1 XG	418	struct module *mod = __module_address((jump_label_t)key);
140fe3b1 XG	419
d430d3d7	420	__jump_label_mod_update(key, enable);
140fe3b1 XG	421
	422	if (mod)
	423	stop = mod->jump_entries + mod->num_jump_entries;
d430d3d7	424	#endif
140fe3b1 XG	425	/* if there are no users, entry can be NULL */
	426	if (entry)
	427	__jump_label_update(key, entry, stop, enable);
d430d3d7 JB	428	}
d430d3d7 JB	429
bf5438fc	430	#endif