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Commit | Line | Data |
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bf5438fc JB |
1 | /* |
2 | * jump label support | |
3 | * | |
4 | * Copyright (C) 2009 Jason Baron <jbaron@redhat.com> | |
90eec103 | 5 | * Copyright (C) 2011 Peter Zijlstra |
bf5438fc JB |
6 | * |
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> | |
c5905afb | 15 | #include <linux/static_key.h> |
851cf6e7 | 16 | #include <linux/jump_label_ratelimit.h> |
bf5438fc JB |
17 | |
18 | #ifdef HAVE_JUMP_LABEL | |
19 | ||
bf5438fc JB |
20 | /* mutex to protect coming/going of the the jump_label table */ |
21 | static DEFINE_MUTEX(jump_label_mutex); | |
22 | ||
91bad2f8 JB |
23 | void jump_label_lock(void) |
24 | { | |
25 | mutex_lock(&jump_label_mutex); | |
26 | } | |
27 | ||
28 | void jump_label_unlock(void) | |
29 | { | |
30 | mutex_unlock(&jump_label_mutex); | |
31 | } | |
32 | ||
bf5438fc JB |
33 | static int jump_label_cmp(const void *a, const void *b) |
34 | { | |
35 | const struct jump_entry *jea = a; | |
36 | const struct jump_entry *jeb = b; | |
37 | ||
38 | if (jea->key < jeb->key) | |
39 | return -1; | |
40 | ||
41 | if (jea->key > jeb->key) | |
42 | return 1; | |
43 | ||
44 | return 0; | |
45 | } | |
46 | ||
47 | static void | |
d430d3d7 | 48 | jump_label_sort_entries(struct jump_entry *start, struct jump_entry *stop) |
bf5438fc JB |
49 | { |
50 | unsigned long size; | |
51 | ||
52 | size = (((unsigned long)stop - (unsigned long)start) | |
53 | / sizeof(struct jump_entry)); | |
54 | sort(start, size, sizeof(struct jump_entry), jump_label_cmp, NULL); | |
55 | } | |
56 | ||
706249c2 | 57 | static void jump_label_update(struct static_key *key); |
a1efb01f | 58 | |
c5905afb | 59 | void static_key_slow_inc(struct static_key *key) |
bf5438fc | 60 | { |
945c6e85 PB |
61 | int v, v1; |
62 | ||
c4b2c0c5 | 63 | STATIC_KEY_CHECK_USE(); |
945c6e85 PB |
64 | |
65 | /* | |
66 | * Careful if we get concurrent static_key_slow_inc() calls; | |
67 | * later calls must wait for the first one to _finish_ the | |
68 | * jump_label_update() process. At the same time, however, | |
69 | * the jump_label_update() call below wants to see | |
70 | * static_key_enabled(&key) for jumps to be updated properly. | |
71 | * | |
72 | * So give a special meaning to negative key->enabled: it sends | |
73 | * static_key_slow_inc() down the slow path, and it is non-zero | |
74 | * so it counts as "enabled" in jump_label_update(). Note that | |
75 | * atomic_inc_unless_negative() checks >= 0, so roll our own. | |
76 | */ | |
77 | for (v = atomic_read(&key->enabled); v > 0; v = v1) { | |
78 | v1 = atomic_cmpxchg(&key->enabled, v, v + 1); | |
79 | if (likely(v1 == v)) | |
80 | return; | |
81 | } | |
bf5438fc | 82 | |
d430d3d7 | 83 | jump_label_lock(); |
945c6e85 PB |
84 | if (atomic_read(&key->enabled) == 0) { |
85 | atomic_set(&key->enabled, -1); | |
706249c2 | 86 | jump_label_update(key); |
945c6e85 PB |
87 | atomic_set(&key->enabled, 1); |
88 | } else { | |
89 | atomic_inc(&key->enabled); | |
90 | } | |
d430d3d7 | 91 | jump_label_unlock(); |
bf5438fc | 92 | } |
c5905afb | 93 | EXPORT_SYMBOL_GPL(static_key_slow_inc); |
bf5438fc | 94 | |
c5905afb | 95 | static void __static_key_slow_dec(struct static_key *key, |
b2029520 | 96 | unsigned long rate_limit, struct delayed_work *work) |
bf5438fc | 97 | { |
945c6e85 PB |
98 | /* |
99 | * The negative count check is valid even when a negative | |
100 | * key->enabled is in use by static_key_slow_inc(); a | |
101 | * __static_key_slow_dec() before the first static_key_slow_inc() | |
102 | * returns is unbalanced, because all other static_key_slow_inc() | |
103 | * instances block while the update is in progress. | |
104 | */ | |
fadf0464 JB |
105 | if (!atomic_dec_and_mutex_lock(&key->enabled, &jump_label_mutex)) { |
106 | WARN(atomic_read(&key->enabled) < 0, | |
107 | "jump label: negative count!\n"); | |
d430d3d7 | 108 | return; |
fadf0464 | 109 | } |
bf5438fc | 110 | |
b2029520 GN |
111 | if (rate_limit) { |
112 | atomic_inc(&key->enabled); | |
113 | schedule_delayed_work(work, rate_limit); | |
c5905afb | 114 | } else { |
706249c2 | 115 | jump_label_update(key); |
c5905afb | 116 | } |
91bad2f8 | 117 | jump_label_unlock(); |
bf5438fc JB |
118 | } |
119 | ||
b2029520 GN |
120 | static void jump_label_update_timeout(struct work_struct *work) |
121 | { | |
c5905afb IM |
122 | struct static_key_deferred *key = |
123 | container_of(work, struct static_key_deferred, work.work); | |
124 | __static_key_slow_dec(&key->key, 0, NULL); | |
b2029520 GN |
125 | } |
126 | ||
c5905afb | 127 | void static_key_slow_dec(struct static_key *key) |
b2029520 | 128 | { |
c4b2c0c5 | 129 | STATIC_KEY_CHECK_USE(); |
c5905afb | 130 | __static_key_slow_dec(key, 0, NULL); |
b2029520 | 131 | } |
c5905afb | 132 | EXPORT_SYMBOL_GPL(static_key_slow_dec); |
b2029520 | 133 | |
c5905afb | 134 | void static_key_slow_dec_deferred(struct static_key_deferred *key) |
b2029520 | 135 | { |
c4b2c0c5 | 136 | STATIC_KEY_CHECK_USE(); |
c5905afb | 137 | __static_key_slow_dec(&key->key, key->timeout, &key->work); |
b2029520 | 138 | } |
c5905afb | 139 | EXPORT_SYMBOL_GPL(static_key_slow_dec_deferred); |
b2029520 | 140 | |
de4d74e5 DM |
141 | void static_key_deferred_flush(struct static_key_deferred *key) |
142 | { | |
143 | STATIC_KEY_CHECK_USE(); | |
144 | flush_delayed_work(&key->work); | |
145 | } | |
146 | EXPORT_SYMBOL_GPL(static_key_deferred_flush); | |
147 | ||
c5905afb | 148 | void jump_label_rate_limit(struct static_key_deferred *key, |
b2029520 GN |
149 | unsigned long rl) |
150 | { | |
c4b2c0c5 | 151 | STATIC_KEY_CHECK_USE(); |
b2029520 GN |
152 | key->timeout = rl; |
153 | INIT_DELAYED_WORK(&key->work, jump_label_update_timeout); | |
154 | } | |
a181dc14 | 155 | EXPORT_SYMBOL_GPL(jump_label_rate_limit); |
b2029520 | 156 | |
4c3ef6d7 JB |
157 | static int addr_conflict(struct jump_entry *entry, void *start, void *end) |
158 | { | |
159 | if (entry->code <= (unsigned long)end && | |
160 | entry->code + JUMP_LABEL_NOP_SIZE > (unsigned long)start) | |
161 | return 1; | |
162 | ||
163 | return 0; | |
164 | } | |
165 | ||
d430d3d7 JB |
166 | static int __jump_label_text_reserved(struct jump_entry *iter_start, |
167 | struct jump_entry *iter_stop, void *start, void *end) | |
4c3ef6d7 | 168 | { |
4c3ef6d7 | 169 | struct jump_entry *iter; |
4c3ef6d7 | 170 | |
4c3ef6d7 JB |
171 | iter = iter_start; |
172 | while (iter < iter_stop) { | |
d430d3d7 JB |
173 | if (addr_conflict(iter, start, end)) |
174 | return 1; | |
4c3ef6d7 JB |
175 | iter++; |
176 | } | |
177 | ||
d430d3d7 JB |
178 | return 0; |
179 | } | |
180 | ||
706249c2 | 181 | /* |
20284aa7 JF |
182 | * Update code which is definitely not currently executing. |
183 | * Architectures which need heavyweight synchronization to modify | |
184 | * running code can override this to make the non-live update case | |
185 | * cheaper. | |
186 | */ | |
9cdbe1cb | 187 | void __weak __init_or_module arch_jump_label_transform_static(struct jump_entry *entry, |
20284aa7 JF |
188 | enum jump_label_type type) |
189 | { | |
706249c2 | 190 | arch_jump_label_transform(entry, type); |
20284aa7 JF |
191 | } |
192 | ||
706249c2 | 193 | static inline struct jump_entry *static_key_entries(struct static_key *key) |
d430d3d7 | 194 | { |
706249c2 | 195 | return (struct jump_entry *)((unsigned long)key->entries & ~JUMP_TYPE_MASK); |
4c3ef6d7 JB |
196 | } |
197 | ||
706249c2 | 198 | static inline bool static_key_type(struct static_key *key) |
c5905afb | 199 | { |
706249c2 | 200 | return (unsigned long)key->entries & JUMP_TYPE_MASK; |
a1efb01f | 201 | } |
c5905afb | 202 | |
7dcfd915 PZ |
203 | static inline struct static_key *jump_entry_key(struct jump_entry *entry) |
204 | { | |
11276d53 PZ |
205 | return (struct static_key *)((unsigned long)entry->key & ~1UL); |
206 | } | |
207 | ||
208 | static bool jump_entry_branch(struct jump_entry *entry) | |
209 | { | |
210 | return (unsigned long)entry->key & 1UL; | |
7dcfd915 PZ |
211 | } |
212 | ||
706249c2 | 213 | static enum jump_label_type jump_label_type(struct jump_entry *entry) |
a1efb01f | 214 | { |
706249c2 | 215 | struct static_key *key = jump_entry_key(entry); |
a1efb01f | 216 | bool enabled = static_key_enabled(key); |
11276d53 | 217 | bool branch = jump_entry_branch(entry); |
c5905afb | 218 | |
11276d53 PZ |
219 | /* See the comment in linux/jump_label.h */ |
220 | return enabled ^ branch; | |
c5905afb IM |
221 | } |
222 | ||
706249c2 PZ |
223 | static void __jump_label_update(struct static_key *key, |
224 | struct jump_entry *entry, | |
225 | struct jump_entry *stop) | |
226 | { | |
227 | for (; (entry < stop) && (jump_entry_key(entry) == key); entry++) { | |
228 | /* | |
229 | * entry->code set to 0 invalidates module init text sections | |
230 | * kernel_text_address() verifies we are not in core kernel | |
231 | * init code, see jump_label_invalidate_module_init(). | |
232 | */ | |
233 | if (entry->code && kernel_text_address(entry->code)) | |
234 | arch_jump_label_transform(entry, jump_label_type(entry)); | |
235 | } | |
236 | } | |
237 | ||
97ce2c88 | 238 | void __init jump_label_init(void) |
bf5438fc | 239 | { |
bf5438fc JB |
240 | struct jump_entry *iter_start = __start___jump_table; |
241 | struct jump_entry *iter_stop = __stop___jump_table; | |
c5905afb | 242 | struct static_key *key = NULL; |
bf5438fc JB |
243 | struct jump_entry *iter; |
244 | ||
91bad2f8 | 245 | jump_label_lock(); |
d430d3d7 JB |
246 | jump_label_sort_entries(iter_start, iter_stop); |
247 | ||
248 | for (iter = iter_start; iter < iter_stop; iter++) { | |
c5905afb | 249 | struct static_key *iterk; |
37348804 | 250 | |
11276d53 PZ |
251 | /* rewrite NOPs */ |
252 | if (jump_label_type(iter) == JUMP_LABEL_NOP) | |
253 | arch_jump_label_transform_static(iter, JUMP_LABEL_NOP); | |
254 | ||
7dcfd915 | 255 | iterk = jump_entry_key(iter); |
37348804 | 256 | if (iterk == key) |
d430d3d7 JB |
257 | continue; |
258 | ||
37348804 | 259 | key = iterk; |
c5905afb IM |
260 | /* |
261 | * Set key->entries to iter, but preserve JUMP_LABEL_TRUE_BRANCH. | |
262 | */ | |
263 | *((unsigned long *)&key->entries) += (unsigned long)iter; | |
d430d3d7 JB |
264 | #ifdef CONFIG_MODULES |
265 | key->next = NULL; | |
266 | #endif | |
bf5438fc | 267 | } |
c4b2c0c5 | 268 | static_key_initialized = true; |
91bad2f8 | 269 | jump_label_unlock(); |
bf5438fc | 270 | } |
bf5438fc JB |
271 | |
272 | #ifdef CONFIG_MODULES | |
273 | ||
11276d53 PZ |
274 | static enum jump_label_type jump_label_init_type(struct jump_entry *entry) |
275 | { | |
276 | struct static_key *key = jump_entry_key(entry); | |
277 | bool type = static_key_type(key); | |
278 | bool branch = jump_entry_branch(entry); | |
279 | ||
280 | /* See the comment in linux/jump_label.h */ | |
281 | return type ^ branch; | |
282 | } | |
283 | ||
c5905afb IM |
284 | struct static_key_mod { |
285 | struct static_key_mod *next; | |
d430d3d7 JB |
286 | struct jump_entry *entries; |
287 | struct module *mod; | |
288 | }; | |
289 | ||
290 | static int __jump_label_mod_text_reserved(void *start, void *end) | |
291 | { | |
292 | struct module *mod; | |
293 | ||
294 | mod = __module_text_address((unsigned long)start); | |
295 | if (!mod) | |
296 | return 0; | |
297 | ||
298 | WARN_ON_ONCE(__module_text_address((unsigned long)end) != mod); | |
299 | ||
300 | return __jump_label_text_reserved(mod->jump_entries, | |
301 | mod->jump_entries + mod->num_jump_entries, | |
302 | start, end); | |
303 | } | |
304 | ||
706249c2 | 305 | static void __jump_label_mod_update(struct static_key *key) |
d430d3d7 | 306 | { |
706249c2 | 307 | struct static_key_mod *mod; |
d430d3d7 | 308 | |
706249c2 | 309 | for (mod = key->next; mod; mod = mod->next) { |
7cbc5b8d JO |
310 | struct module *m = mod->mod; |
311 | ||
312 | __jump_label_update(key, mod->entries, | |
706249c2 | 313 | m->jump_entries + m->num_jump_entries); |
d430d3d7 JB |
314 | } |
315 | } | |
316 | ||
317 | /*** | |
318 | * apply_jump_label_nops - patch module jump labels with arch_get_jump_label_nop() | |
319 | * @mod: module to patch | |
320 | * | |
321 | * Allow for run-time selection of the optimal nops. Before the module | |
322 | * loads patch these with arch_get_jump_label_nop(), which is specified by | |
323 | * the arch specific jump label code. | |
324 | */ | |
325 | void jump_label_apply_nops(struct module *mod) | |
bf5438fc | 326 | { |
d430d3d7 JB |
327 | struct jump_entry *iter_start = mod->jump_entries; |
328 | struct jump_entry *iter_stop = iter_start + mod->num_jump_entries; | |
329 | struct jump_entry *iter; | |
330 | ||
331 | /* if the module doesn't have jump label entries, just return */ | |
332 | if (iter_start == iter_stop) | |
333 | return; | |
334 | ||
11276d53 PZ |
335 | for (iter = iter_start; iter < iter_stop; iter++) { |
336 | /* Only write NOPs for arch_branch_static(). */ | |
337 | if (jump_label_init_type(iter) == JUMP_LABEL_NOP) | |
338 | arch_jump_label_transform_static(iter, JUMP_LABEL_NOP); | |
339 | } | |
bf5438fc JB |
340 | } |
341 | ||
d430d3d7 | 342 | static int jump_label_add_module(struct module *mod) |
bf5438fc | 343 | { |
d430d3d7 JB |
344 | struct jump_entry *iter_start = mod->jump_entries; |
345 | struct jump_entry *iter_stop = iter_start + mod->num_jump_entries; | |
346 | struct jump_entry *iter; | |
c5905afb IM |
347 | struct static_key *key = NULL; |
348 | struct static_key_mod *jlm; | |
bf5438fc JB |
349 | |
350 | /* if the module doesn't have jump label entries, just return */ | |
d430d3d7 | 351 | if (iter_start == iter_stop) |
bf5438fc JB |
352 | return 0; |
353 | ||
d430d3d7 JB |
354 | jump_label_sort_entries(iter_start, iter_stop); |
355 | ||
356 | for (iter = iter_start; iter < iter_stop; iter++) { | |
c5905afb | 357 | struct static_key *iterk; |
d430d3d7 | 358 | |
7dcfd915 | 359 | iterk = jump_entry_key(iter); |
c5905afb IM |
360 | if (iterk == key) |
361 | continue; | |
d430d3d7 | 362 | |
c5905afb | 363 | key = iterk; |
bed831f9 | 364 | if (within_module(iter->key, mod)) { |
c5905afb IM |
365 | /* |
366 | * Set key->entries to iter, but preserve JUMP_LABEL_TRUE_BRANCH. | |
367 | */ | |
368 | *((unsigned long *)&key->entries) += (unsigned long)iter; | |
d430d3d7 JB |
369 | key->next = NULL; |
370 | continue; | |
bf5438fc | 371 | } |
c5905afb | 372 | jlm = kzalloc(sizeof(struct static_key_mod), GFP_KERNEL); |
d430d3d7 JB |
373 | if (!jlm) |
374 | return -ENOMEM; | |
d430d3d7 JB |
375 | jlm->mod = mod; |
376 | jlm->entries = iter; | |
377 | jlm->next = key->next; | |
378 | key->next = jlm; | |
379 | ||
11276d53 PZ |
380 | /* Only update if we've changed from our initial state */ |
381 | if (jump_label_type(iter) != jump_label_init_type(iter)) | |
706249c2 | 382 | __jump_label_update(key, iter, iter_stop); |
bf5438fc | 383 | } |
d430d3d7 | 384 | |
bf5438fc JB |
385 | return 0; |
386 | } | |
387 | ||
d430d3d7 | 388 | static void jump_label_del_module(struct module *mod) |
bf5438fc | 389 | { |
d430d3d7 JB |
390 | struct jump_entry *iter_start = mod->jump_entries; |
391 | struct jump_entry *iter_stop = iter_start + mod->num_jump_entries; | |
392 | struct jump_entry *iter; | |
c5905afb IM |
393 | struct static_key *key = NULL; |
394 | struct static_key_mod *jlm, **prev; | |
bf5438fc | 395 | |
d430d3d7 | 396 | for (iter = iter_start; iter < iter_stop; iter++) { |
7dcfd915 | 397 | if (jump_entry_key(iter) == key) |
d430d3d7 JB |
398 | continue; |
399 | ||
7dcfd915 | 400 | key = jump_entry_key(iter); |
d430d3d7 | 401 | |
bed831f9 | 402 | if (within_module(iter->key, mod)) |
d430d3d7 JB |
403 | continue; |
404 | ||
405 | prev = &key->next; | |
406 | jlm = key->next; | |
bf5438fc | 407 | |
d430d3d7 JB |
408 | while (jlm && jlm->mod != mod) { |
409 | prev = &jlm->next; | |
410 | jlm = jlm->next; | |
411 | } | |
412 | ||
413 | if (jlm) { | |
414 | *prev = jlm->next; | |
415 | kfree(jlm); | |
bf5438fc JB |
416 | } |
417 | } | |
418 | } | |
419 | ||
d430d3d7 | 420 | static void jump_label_invalidate_module_init(struct module *mod) |
b842f8fa | 421 | { |
d430d3d7 JB |
422 | struct jump_entry *iter_start = mod->jump_entries; |
423 | struct jump_entry *iter_stop = iter_start + mod->num_jump_entries; | |
b842f8fa | 424 | struct jump_entry *iter; |
b842f8fa | 425 | |
d430d3d7 JB |
426 | for (iter = iter_start; iter < iter_stop; iter++) { |
427 | if (within_module_init(iter->code, mod)) | |
428 | iter->code = 0; | |
b842f8fa JB |
429 | } |
430 | } | |
431 | ||
bf5438fc JB |
432 | static int |
433 | jump_label_module_notify(struct notifier_block *self, unsigned long val, | |
434 | void *data) | |
435 | { | |
436 | struct module *mod = data; | |
437 | int ret = 0; | |
438 | ||
439 | switch (val) { | |
440 | case MODULE_STATE_COMING: | |
91bad2f8 | 441 | jump_label_lock(); |
d430d3d7 | 442 | ret = jump_label_add_module(mod); |
bf5438fc | 443 | if (ret) |
d430d3d7 | 444 | jump_label_del_module(mod); |
91bad2f8 | 445 | jump_label_unlock(); |
bf5438fc JB |
446 | break; |
447 | case MODULE_STATE_GOING: | |
91bad2f8 | 448 | jump_label_lock(); |
d430d3d7 | 449 | jump_label_del_module(mod); |
91bad2f8 | 450 | jump_label_unlock(); |
bf5438fc | 451 | break; |
b842f8fa | 452 | case MODULE_STATE_LIVE: |
91bad2f8 | 453 | jump_label_lock(); |
d430d3d7 | 454 | jump_label_invalidate_module_init(mod); |
91bad2f8 | 455 | jump_label_unlock(); |
b842f8fa | 456 | break; |
bf5438fc | 457 | } |
bf5438fc | 458 | |
d430d3d7 | 459 | return notifier_from_errno(ret); |
bf5438fc JB |
460 | } |
461 | ||
462 | struct notifier_block jump_label_module_nb = { | |
463 | .notifier_call = jump_label_module_notify, | |
d430d3d7 | 464 | .priority = 1, /* higher than tracepoints */ |
bf5438fc JB |
465 | }; |
466 | ||
d430d3d7 | 467 | static __init int jump_label_init_module(void) |
bf5438fc JB |
468 | { |
469 | return register_module_notifier(&jump_label_module_nb); | |
470 | } | |
d430d3d7 | 471 | early_initcall(jump_label_init_module); |
bf5438fc JB |
472 | |
473 | #endif /* CONFIG_MODULES */ | |
474 | ||
d430d3d7 JB |
475 | /*** |
476 | * jump_label_text_reserved - check if addr range is reserved | |
477 | * @start: start text addr | |
478 | * @end: end text addr | |
479 | * | |
480 | * checks if the text addr located between @start and @end | |
481 | * overlaps with any of the jump label patch addresses. Code | |
482 | * that wants to modify kernel text should first verify that | |
483 | * it does not overlap with any of the jump label addresses. | |
484 | * Caller must hold jump_label_mutex. | |
485 | * | |
486 | * returns 1 if there is an overlap, 0 otherwise | |
487 | */ | |
488 | int jump_label_text_reserved(void *start, void *end) | |
489 | { | |
490 | int ret = __jump_label_text_reserved(__start___jump_table, | |
491 | __stop___jump_table, start, end); | |
492 | ||
493 | if (ret) | |
494 | return ret; | |
495 | ||
496 | #ifdef CONFIG_MODULES | |
497 | ret = __jump_label_mod_text_reserved(start, end); | |
498 | #endif | |
499 | return ret; | |
500 | } | |
501 | ||
706249c2 | 502 | static void jump_label_update(struct static_key *key) |
d430d3d7 | 503 | { |
c5905afb | 504 | struct jump_entry *stop = __stop___jump_table; |
a1efb01f | 505 | struct jump_entry *entry = static_key_entries(key); |
d430d3d7 | 506 | #ifdef CONFIG_MODULES |
bed831f9 | 507 | struct module *mod; |
140fe3b1 | 508 | |
706249c2 | 509 | __jump_label_mod_update(key); |
140fe3b1 | 510 | |
bed831f9 PZ |
511 | preempt_disable(); |
512 | mod = __module_address((unsigned long)key); | |
140fe3b1 XG |
513 | if (mod) |
514 | stop = mod->jump_entries + mod->num_jump_entries; | |
bed831f9 | 515 | preempt_enable(); |
d430d3d7 | 516 | #endif |
140fe3b1 XG |
517 | /* if there are no users, entry can be NULL */ |
518 | if (entry) | |
706249c2 | 519 | __jump_label_update(key, entry, stop); |
d430d3d7 JB |
520 | } |
521 | ||
1987c947 PZ |
522 | #ifdef CONFIG_STATIC_KEYS_SELFTEST |
523 | static DEFINE_STATIC_KEY_TRUE(sk_true); | |
524 | static DEFINE_STATIC_KEY_FALSE(sk_false); | |
525 | ||
526 | static __init int jump_label_test(void) | |
527 | { | |
528 | int i; | |
529 | ||
530 | for (i = 0; i < 2; i++) { | |
531 | WARN_ON(static_key_enabled(&sk_true.key) != true); | |
532 | WARN_ON(static_key_enabled(&sk_false.key) != false); | |
533 | ||
534 | WARN_ON(!static_branch_likely(&sk_true)); | |
535 | WARN_ON(!static_branch_unlikely(&sk_true)); | |
536 | WARN_ON(static_branch_likely(&sk_false)); | |
537 | WARN_ON(static_branch_unlikely(&sk_false)); | |
538 | ||
539 | static_branch_disable(&sk_true); | |
540 | static_branch_enable(&sk_false); | |
541 | ||
542 | WARN_ON(static_key_enabled(&sk_true.key) == true); | |
543 | WARN_ON(static_key_enabled(&sk_false.key) == false); | |
544 | ||
545 | WARN_ON(static_branch_likely(&sk_true)); | |
546 | WARN_ON(static_branch_unlikely(&sk_true)); | |
547 | WARN_ON(!static_branch_likely(&sk_false)); | |
548 | WARN_ON(!static_branch_unlikely(&sk_false)); | |
549 | ||
550 | static_branch_enable(&sk_true); | |
551 | static_branch_disable(&sk_false); | |
552 | } | |
553 | ||
554 | return 0; | |
555 | } | |
de684062 | 556 | early_initcall(jump_label_test); |
1987c947 PZ |
557 | #endif /* STATIC_KEYS_SELFTEST */ |
558 | ||
559 | #endif /* HAVE_JUMP_LABEL */ |