Commit | Line | Data |
---|---|---|
3ac7fe5a TG |
1 | /* |
2 | * Generic infrastructure for lifetime debugging of objects. | |
3 | * | |
4 | * Started by Thomas Gleixner | |
5 | * | |
6 | * Copyright (C) 2008, Thomas Gleixner <tglx@linutronix.de> | |
7 | * | |
8 | * For licencing details see kernel-base/COPYING | |
9 | */ | |
10 | #include <linux/debugobjects.h> | |
11 | #include <linux/interrupt.h> | |
d43c36dc | 12 | #include <linux/sched.h> |
3ac7fe5a TG |
13 | #include <linux/seq_file.h> |
14 | #include <linux/debugfs.h> | |
5a0e3ad6 | 15 | #include <linux/slab.h> |
3ac7fe5a TG |
16 | #include <linux/hash.h> |
17 | ||
18 | #define ODEBUG_HASH_BITS 14 | |
19 | #define ODEBUG_HASH_SIZE (1 << ODEBUG_HASH_BITS) | |
20 | ||
21 | #define ODEBUG_POOL_SIZE 512 | |
22 | #define ODEBUG_POOL_MIN_LEVEL 256 | |
23 | ||
24 | #define ODEBUG_CHUNK_SHIFT PAGE_SHIFT | |
25 | #define ODEBUG_CHUNK_SIZE (1 << ODEBUG_CHUNK_SHIFT) | |
26 | #define ODEBUG_CHUNK_MASK (~(ODEBUG_CHUNK_SIZE - 1)) | |
27 | ||
28 | struct debug_bucket { | |
29 | struct hlist_head list; | |
aef9cb05 | 30 | raw_spinlock_t lock; |
3ac7fe5a TG |
31 | }; |
32 | ||
33 | static struct debug_bucket obj_hash[ODEBUG_HASH_SIZE]; | |
34 | ||
1be1cb7b | 35 | static struct debug_obj obj_static_pool[ODEBUG_POOL_SIZE] __initdata; |
3ac7fe5a | 36 | |
aef9cb05 | 37 | static DEFINE_RAW_SPINLOCK(pool_lock); |
3ac7fe5a TG |
38 | |
39 | static HLIST_HEAD(obj_pool); | |
40 | ||
41 | static int obj_pool_min_free = ODEBUG_POOL_SIZE; | |
42 | static int obj_pool_free = ODEBUG_POOL_SIZE; | |
43 | static int obj_pool_used; | |
44 | static int obj_pool_max_used; | |
45 | static struct kmem_cache *obj_cache; | |
46 | ||
47 | static int debug_objects_maxchain __read_mostly; | |
48 | static int debug_objects_fixups __read_mostly; | |
49 | static int debug_objects_warnings __read_mostly; | |
3ae70205 IM |
50 | static int debug_objects_enabled __read_mostly |
51 | = CONFIG_DEBUG_OBJECTS_ENABLE_DEFAULT; | |
52 | ||
3ac7fe5a TG |
53 | static struct debug_obj_descr *descr_test __read_mostly; |
54 | ||
337fff8b TG |
55 | static void free_obj_work(struct work_struct *work); |
56 | static DECLARE_WORK(debug_obj_work, free_obj_work); | |
57 | ||
3ac7fe5a TG |
58 | static int __init enable_object_debug(char *str) |
59 | { | |
60 | debug_objects_enabled = 1; | |
61 | return 0; | |
62 | } | |
3e8ebb5c KM |
63 | |
64 | static int __init disable_object_debug(char *str) | |
65 | { | |
66 | debug_objects_enabled = 0; | |
67 | return 0; | |
68 | } | |
69 | ||
3ac7fe5a | 70 | early_param("debug_objects", enable_object_debug); |
3e8ebb5c | 71 | early_param("no_debug_objects", disable_object_debug); |
3ac7fe5a TG |
72 | |
73 | static const char *obj_states[ODEBUG_STATE_MAX] = { | |
74 | [ODEBUG_STATE_NONE] = "none", | |
75 | [ODEBUG_STATE_INIT] = "initialized", | |
76 | [ODEBUG_STATE_INACTIVE] = "inactive", | |
77 | [ODEBUG_STATE_ACTIVE] = "active", | |
78 | [ODEBUG_STATE_DESTROYED] = "destroyed", | |
79 | [ODEBUG_STATE_NOTAVAILABLE] = "not available", | |
80 | }; | |
81 | ||
1fda107d | 82 | static void fill_pool(void) |
3ac7fe5a TG |
83 | { |
84 | gfp_t gfp = GFP_ATOMIC | __GFP_NORETRY | __GFP_NOWARN; | |
85 | struct debug_obj *new; | |
50db04dd | 86 | unsigned long flags; |
3ac7fe5a TG |
87 | |
88 | if (likely(obj_pool_free >= ODEBUG_POOL_MIN_LEVEL)) | |
1fda107d | 89 | return; |
3ac7fe5a TG |
90 | |
91 | if (unlikely(!obj_cache)) | |
1fda107d | 92 | return; |
3ac7fe5a TG |
93 | |
94 | while (obj_pool_free < ODEBUG_POOL_MIN_LEVEL) { | |
95 | ||
96 | new = kmem_cache_zalloc(obj_cache, gfp); | |
97 | if (!new) | |
3340808c | 98 | return; |
3ac7fe5a | 99 | |
aef9cb05 | 100 | raw_spin_lock_irqsave(&pool_lock, flags); |
3ac7fe5a TG |
101 | hlist_add_head(&new->node, &obj_pool); |
102 | obj_pool_free++; | |
aef9cb05 | 103 | raw_spin_unlock_irqrestore(&pool_lock, flags); |
3ac7fe5a | 104 | } |
3ac7fe5a TG |
105 | } |
106 | ||
107 | /* | |
108 | * Lookup an object in the hash bucket. | |
109 | */ | |
110 | static struct debug_obj *lookup_object(void *addr, struct debug_bucket *b) | |
111 | { | |
3ac7fe5a TG |
112 | struct debug_obj *obj; |
113 | int cnt = 0; | |
114 | ||
b67bfe0d | 115 | hlist_for_each_entry(obj, &b->list, node) { |
3ac7fe5a TG |
116 | cnt++; |
117 | if (obj->object == addr) | |
118 | return obj; | |
119 | } | |
120 | if (cnt > debug_objects_maxchain) | |
121 | debug_objects_maxchain = cnt; | |
122 | ||
123 | return NULL; | |
124 | } | |
125 | ||
126 | /* | |
50db04dd | 127 | * Allocate a new object. If the pool is empty, switch off the debugger. |
673d62cc | 128 | * Must be called with interrupts disabled. |
3ac7fe5a TG |
129 | */ |
130 | static struct debug_obj * | |
131 | alloc_object(void *addr, struct debug_bucket *b, struct debug_obj_descr *descr) | |
132 | { | |
133 | struct debug_obj *obj = NULL; | |
3ac7fe5a | 134 | |
aef9cb05 | 135 | raw_spin_lock(&pool_lock); |
3ac7fe5a TG |
136 | if (obj_pool.first) { |
137 | obj = hlist_entry(obj_pool.first, typeof(*obj), node); | |
138 | ||
139 | obj->object = addr; | |
140 | obj->descr = descr; | |
141 | obj->state = ODEBUG_STATE_NONE; | |
a5d8e467 | 142 | obj->astate = 0; |
3ac7fe5a TG |
143 | hlist_del(&obj->node); |
144 | ||
145 | hlist_add_head(&obj->node, &b->list); | |
146 | ||
147 | obj_pool_used++; | |
148 | if (obj_pool_used > obj_pool_max_used) | |
149 | obj_pool_max_used = obj_pool_used; | |
150 | ||
151 | obj_pool_free--; | |
152 | if (obj_pool_free < obj_pool_min_free) | |
153 | obj_pool_min_free = obj_pool_free; | |
154 | } | |
aef9cb05 | 155 | raw_spin_unlock(&pool_lock); |
3ac7fe5a | 156 | |
3ac7fe5a TG |
157 | return obj; |
158 | } | |
159 | ||
160 | /* | |
337fff8b | 161 | * workqueue function to free objects. |
3ac7fe5a | 162 | */ |
337fff8b | 163 | static void free_obj_work(struct work_struct *work) |
3ac7fe5a | 164 | { |
337fff8b | 165 | struct debug_obj *obj; |
673d62cc | 166 | unsigned long flags; |
3ac7fe5a | 167 | |
aef9cb05 | 168 | raw_spin_lock_irqsave(&pool_lock, flags); |
337fff8b TG |
169 | while (obj_pool_free > ODEBUG_POOL_SIZE) { |
170 | obj = hlist_entry(obj_pool.first, typeof(*obj), node); | |
171 | hlist_del(&obj->node); | |
172 | obj_pool_free--; | |
173 | /* | |
174 | * We release pool_lock across kmem_cache_free() to | |
175 | * avoid contention on pool_lock. | |
176 | */ | |
aef9cb05 | 177 | raw_spin_unlock_irqrestore(&pool_lock, flags); |
3ac7fe5a | 178 | kmem_cache_free(obj_cache, obj); |
aef9cb05 | 179 | raw_spin_lock_irqsave(&pool_lock, flags); |
3ac7fe5a | 180 | } |
aef9cb05 | 181 | raw_spin_unlock_irqrestore(&pool_lock, flags); |
337fff8b TG |
182 | } |
183 | ||
184 | /* | |
185 | * Put the object back into the pool and schedule work to free objects | |
186 | * if necessary. | |
187 | */ | |
188 | static void free_object(struct debug_obj *obj) | |
189 | { | |
190 | unsigned long flags; | |
191 | int sched = 0; | |
192 | ||
aef9cb05 | 193 | raw_spin_lock_irqsave(&pool_lock, flags); |
337fff8b TG |
194 | /* |
195 | * schedule work when the pool is filled and the cache is | |
196 | * initialized: | |
197 | */ | |
198 | if (obj_pool_free > ODEBUG_POOL_SIZE && obj_cache) | |
161b6ae0 | 199 | sched = keventd_up() && !work_pending(&debug_obj_work); |
337fff8b TG |
200 | hlist_add_head(&obj->node, &obj_pool); |
201 | obj_pool_free++; | |
202 | obj_pool_used--; | |
aef9cb05 | 203 | raw_spin_unlock_irqrestore(&pool_lock, flags); |
337fff8b TG |
204 | if (sched) |
205 | schedule_work(&debug_obj_work); | |
3ac7fe5a TG |
206 | } |
207 | ||
208 | /* | |
209 | * We run out of memory. That means we probably have tons of objects | |
210 | * allocated. | |
211 | */ | |
212 | static void debug_objects_oom(void) | |
213 | { | |
214 | struct debug_bucket *db = obj_hash; | |
b67bfe0d | 215 | struct hlist_node *tmp; |
673d62cc | 216 | HLIST_HEAD(freelist); |
3ac7fe5a TG |
217 | struct debug_obj *obj; |
218 | unsigned long flags; | |
219 | int i; | |
220 | ||
221 | printk(KERN_WARNING "ODEBUG: Out of memory. ODEBUG disabled\n"); | |
222 | ||
223 | for (i = 0; i < ODEBUG_HASH_SIZE; i++, db++) { | |
aef9cb05 | 224 | raw_spin_lock_irqsave(&db->lock, flags); |
673d62cc | 225 | hlist_move_list(&db->list, &freelist); |
aef9cb05 | 226 | raw_spin_unlock_irqrestore(&db->lock, flags); |
673d62cc VN |
227 | |
228 | /* Now free them */ | |
b67bfe0d | 229 | hlist_for_each_entry_safe(obj, tmp, &freelist, node) { |
3ac7fe5a TG |
230 | hlist_del(&obj->node); |
231 | free_object(obj); | |
232 | } | |
3ac7fe5a TG |
233 | } |
234 | } | |
235 | ||
236 | /* | |
237 | * We use the pfn of the address for the hash. That way we can check | |
238 | * for freed objects simply by checking the affected bucket. | |
239 | */ | |
240 | static struct debug_bucket *get_bucket(unsigned long addr) | |
241 | { | |
242 | unsigned long hash; | |
243 | ||
244 | hash = hash_long((addr >> ODEBUG_CHUNK_SHIFT), ODEBUG_HASH_BITS); | |
245 | return &obj_hash[hash]; | |
246 | } | |
247 | ||
248 | static void debug_print_object(struct debug_obj *obj, char *msg) | |
249 | { | |
99777288 | 250 | struct debug_obj_descr *descr = obj->descr; |
3ac7fe5a TG |
251 | static int limit; |
252 | ||
99777288 SG |
253 | if (limit < 5 && descr != descr_test) { |
254 | void *hint = descr->debug_hint ? | |
255 | descr->debug_hint(obj->object) : NULL; | |
3ac7fe5a | 256 | limit++; |
a5d8e467 | 257 | WARN(1, KERN_ERR "ODEBUG: %s %s (active state %u) " |
99777288 | 258 | "object type: %s hint: %pS\n", |
a5d8e467 | 259 | msg, obj_states[obj->state], obj->astate, |
99777288 | 260 | descr->name, hint); |
3ac7fe5a TG |
261 | } |
262 | debug_objects_warnings++; | |
263 | } | |
264 | ||
265 | /* | |
266 | * Try to repair the damage, so we have a better chance to get useful | |
267 | * debug output. | |
268 | */ | |
feac18dd | 269 | static int |
3ac7fe5a TG |
270 | debug_object_fixup(int (*fixup)(void *addr, enum debug_obj_state state), |
271 | void * addr, enum debug_obj_state state) | |
272 | { | |
feac18dd SB |
273 | int fixed = 0; |
274 | ||
3ac7fe5a | 275 | if (fixup) |
feac18dd SB |
276 | fixed = fixup(addr, state); |
277 | debug_objects_fixups += fixed; | |
278 | return fixed; | |
3ac7fe5a TG |
279 | } |
280 | ||
281 | static void debug_object_is_on_stack(void *addr, int onstack) | |
282 | { | |
3ac7fe5a TG |
283 | int is_on_stack; |
284 | static int limit; | |
285 | ||
286 | if (limit > 4) | |
287 | return; | |
288 | ||
8b05c7e6 | 289 | is_on_stack = object_is_on_stack(addr); |
3ac7fe5a TG |
290 | if (is_on_stack == onstack) |
291 | return; | |
292 | ||
293 | limit++; | |
294 | if (is_on_stack) | |
295 | printk(KERN_WARNING | |
296 | "ODEBUG: object is on stack, but not annotated\n"); | |
297 | else | |
298 | printk(KERN_WARNING | |
299 | "ODEBUG: object is not on stack, but annotated\n"); | |
300 | WARN_ON(1); | |
301 | } | |
302 | ||
303 | static void | |
304 | __debug_object_init(void *addr, struct debug_obj_descr *descr, int onstack) | |
305 | { | |
306 | enum debug_obj_state state; | |
307 | struct debug_bucket *db; | |
308 | struct debug_obj *obj; | |
309 | unsigned long flags; | |
310 | ||
50db04dd VN |
311 | fill_pool(); |
312 | ||
3ac7fe5a TG |
313 | db = get_bucket((unsigned long) addr); |
314 | ||
aef9cb05 | 315 | raw_spin_lock_irqsave(&db->lock, flags); |
3ac7fe5a TG |
316 | |
317 | obj = lookup_object(addr, db); | |
318 | if (!obj) { | |
319 | obj = alloc_object(addr, db, descr); | |
320 | if (!obj) { | |
321 | debug_objects_enabled = 0; | |
aef9cb05 | 322 | raw_spin_unlock_irqrestore(&db->lock, flags); |
3ac7fe5a TG |
323 | debug_objects_oom(); |
324 | return; | |
325 | } | |
326 | debug_object_is_on_stack(addr, onstack); | |
327 | } | |
328 | ||
329 | switch (obj->state) { | |
330 | case ODEBUG_STATE_NONE: | |
331 | case ODEBUG_STATE_INIT: | |
332 | case ODEBUG_STATE_INACTIVE: | |
333 | obj->state = ODEBUG_STATE_INIT; | |
334 | break; | |
335 | ||
336 | case ODEBUG_STATE_ACTIVE: | |
337 | debug_print_object(obj, "init"); | |
338 | state = obj->state; | |
aef9cb05 | 339 | raw_spin_unlock_irqrestore(&db->lock, flags); |
3ac7fe5a TG |
340 | debug_object_fixup(descr->fixup_init, addr, state); |
341 | return; | |
342 | ||
343 | case ODEBUG_STATE_DESTROYED: | |
344 | debug_print_object(obj, "init"); | |
345 | break; | |
346 | default: | |
347 | break; | |
348 | } | |
349 | ||
aef9cb05 | 350 | raw_spin_unlock_irqrestore(&db->lock, flags); |
3ac7fe5a TG |
351 | } |
352 | ||
353 | /** | |
354 | * debug_object_init - debug checks when an object is initialized | |
355 | * @addr: address of the object | |
356 | * @descr: pointer to an object specific debug description structure | |
357 | */ | |
358 | void debug_object_init(void *addr, struct debug_obj_descr *descr) | |
359 | { | |
360 | if (!debug_objects_enabled) | |
361 | return; | |
362 | ||
363 | __debug_object_init(addr, descr, 0); | |
364 | } | |
365 | ||
366 | /** | |
367 | * debug_object_init_on_stack - debug checks when an object on stack is | |
368 | * initialized | |
369 | * @addr: address of the object | |
370 | * @descr: pointer to an object specific debug description structure | |
371 | */ | |
372 | void debug_object_init_on_stack(void *addr, struct debug_obj_descr *descr) | |
373 | { | |
374 | if (!debug_objects_enabled) | |
375 | return; | |
376 | ||
377 | __debug_object_init(addr, descr, 1); | |
378 | } | |
379 | ||
380 | /** | |
381 | * debug_object_activate - debug checks when an object is activated | |
382 | * @addr: address of the object | |
383 | * @descr: pointer to an object specific debug description structure | |
384 | */ | |
385 | void debug_object_activate(void *addr, struct debug_obj_descr *descr) | |
386 | { | |
387 | enum debug_obj_state state; | |
388 | struct debug_bucket *db; | |
389 | struct debug_obj *obj; | |
390 | unsigned long flags; | |
feac18dd SB |
391 | struct debug_obj o = { .object = addr, |
392 | .state = ODEBUG_STATE_NOTAVAILABLE, | |
393 | .descr = descr }; | |
3ac7fe5a TG |
394 | |
395 | if (!debug_objects_enabled) | |
396 | return; | |
397 | ||
398 | db = get_bucket((unsigned long) addr); | |
399 | ||
aef9cb05 | 400 | raw_spin_lock_irqsave(&db->lock, flags); |
3ac7fe5a TG |
401 | |
402 | obj = lookup_object(addr, db); | |
403 | if (obj) { | |
404 | switch (obj->state) { | |
405 | case ODEBUG_STATE_INIT: | |
406 | case ODEBUG_STATE_INACTIVE: | |
407 | obj->state = ODEBUG_STATE_ACTIVE; | |
408 | break; | |
409 | ||
410 | case ODEBUG_STATE_ACTIVE: | |
411 | debug_print_object(obj, "activate"); | |
412 | state = obj->state; | |
aef9cb05 | 413 | raw_spin_unlock_irqrestore(&db->lock, flags); |
3ac7fe5a TG |
414 | debug_object_fixup(descr->fixup_activate, addr, state); |
415 | return; | |
416 | ||
417 | case ODEBUG_STATE_DESTROYED: | |
418 | debug_print_object(obj, "activate"); | |
419 | break; | |
420 | default: | |
421 | break; | |
422 | } | |
aef9cb05 | 423 | raw_spin_unlock_irqrestore(&db->lock, flags); |
3ac7fe5a TG |
424 | return; |
425 | } | |
426 | ||
aef9cb05 | 427 | raw_spin_unlock_irqrestore(&db->lock, flags); |
3ac7fe5a TG |
428 | /* |
429 | * This happens when a static object is activated. We | |
430 | * let the type specific code decide whether this is | |
431 | * true or not. | |
432 | */ | |
feac18dd SB |
433 | if (debug_object_fixup(descr->fixup_activate, addr, |
434 | ODEBUG_STATE_NOTAVAILABLE)) | |
435 | debug_print_object(&o, "activate"); | |
3ac7fe5a TG |
436 | } |
437 | ||
438 | /** | |
439 | * debug_object_deactivate - debug checks when an object is deactivated | |
440 | * @addr: address of the object | |
441 | * @descr: pointer to an object specific debug description structure | |
442 | */ | |
443 | void debug_object_deactivate(void *addr, struct debug_obj_descr *descr) | |
444 | { | |
445 | struct debug_bucket *db; | |
446 | struct debug_obj *obj; | |
447 | unsigned long flags; | |
448 | ||
449 | if (!debug_objects_enabled) | |
450 | return; | |
451 | ||
452 | db = get_bucket((unsigned long) addr); | |
453 | ||
aef9cb05 | 454 | raw_spin_lock_irqsave(&db->lock, flags); |
3ac7fe5a TG |
455 | |
456 | obj = lookup_object(addr, db); | |
457 | if (obj) { | |
458 | switch (obj->state) { | |
459 | case ODEBUG_STATE_INIT: | |
460 | case ODEBUG_STATE_INACTIVE: | |
461 | case ODEBUG_STATE_ACTIVE: | |
a5d8e467 MD |
462 | if (!obj->astate) |
463 | obj->state = ODEBUG_STATE_INACTIVE; | |
464 | else | |
465 | debug_print_object(obj, "deactivate"); | |
3ac7fe5a TG |
466 | break; |
467 | ||
468 | case ODEBUG_STATE_DESTROYED: | |
469 | debug_print_object(obj, "deactivate"); | |
470 | break; | |
471 | default: | |
472 | break; | |
473 | } | |
474 | } else { | |
475 | struct debug_obj o = { .object = addr, | |
476 | .state = ODEBUG_STATE_NOTAVAILABLE, | |
477 | .descr = descr }; | |
478 | ||
479 | debug_print_object(&o, "deactivate"); | |
480 | } | |
481 | ||
aef9cb05 | 482 | raw_spin_unlock_irqrestore(&db->lock, flags); |
3ac7fe5a TG |
483 | } |
484 | ||
485 | /** | |
486 | * debug_object_destroy - debug checks when an object is destroyed | |
487 | * @addr: address of the object | |
488 | * @descr: pointer to an object specific debug description structure | |
489 | */ | |
490 | void debug_object_destroy(void *addr, struct debug_obj_descr *descr) | |
491 | { | |
492 | enum debug_obj_state state; | |
493 | struct debug_bucket *db; | |
494 | struct debug_obj *obj; | |
495 | unsigned long flags; | |
496 | ||
497 | if (!debug_objects_enabled) | |
498 | return; | |
499 | ||
500 | db = get_bucket((unsigned long) addr); | |
501 | ||
aef9cb05 | 502 | raw_spin_lock_irqsave(&db->lock, flags); |
3ac7fe5a TG |
503 | |
504 | obj = lookup_object(addr, db); | |
505 | if (!obj) | |
506 | goto out_unlock; | |
507 | ||
508 | switch (obj->state) { | |
509 | case ODEBUG_STATE_NONE: | |
510 | case ODEBUG_STATE_INIT: | |
511 | case ODEBUG_STATE_INACTIVE: | |
512 | obj->state = ODEBUG_STATE_DESTROYED; | |
513 | break; | |
514 | case ODEBUG_STATE_ACTIVE: | |
515 | debug_print_object(obj, "destroy"); | |
516 | state = obj->state; | |
aef9cb05 | 517 | raw_spin_unlock_irqrestore(&db->lock, flags); |
3ac7fe5a TG |
518 | debug_object_fixup(descr->fixup_destroy, addr, state); |
519 | return; | |
520 | ||
521 | case ODEBUG_STATE_DESTROYED: | |
522 | debug_print_object(obj, "destroy"); | |
523 | break; | |
524 | default: | |
525 | break; | |
526 | } | |
527 | out_unlock: | |
aef9cb05 | 528 | raw_spin_unlock_irqrestore(&db->lock, flags); |
3ac7fe5a TG |
529 | } |
530 | ||
531 | /** | |
532 | * debug_object_free - debug checks when an object is freed | |
533 | * @addr: address of the object | |
534 | * @descr: pointer to an object specific debug description structure | |
535 | */ | |
536 | void debug_object_free(void *addr, struct debug_obj_descr *descr) | |
537 | { | |
538 | enum debug_obj_state state; | |
539 | struct debug_bucket *db; | |
540 | struct debug_obj *obj; | |
541 | unsigned long flags; | |
542 | ||
543 | if (!debug_objects_enabled) | |
544 | return; | |
545 | ||
546 | db = get_bucket((unsigned long) addr); | |
547 | ||
aef9cb05 | 548 | raw_spin_lock_irqsave(&db->lock, flags); |
3ac7fe5a TG |
549 | |
550 | obj = lookup_object(addr, db); | |
551 | if (!obj) | |
552 | goto out_unlock; | |
553 | ||
554 | switch (obj->state) { | |
555 | case ODEBUG_STATE_ACTIVE: | |
556 | debug_print_object(obj, "free"); | |
557 | state = obj->state; | |
aef9cb05 | 558 | raw_spin_unlock_irqrestore(&db->lock, flags); |
3ac7fe5a TG |
559 | debug_object_fixup(descr->fixup_free, addr, state); |
560 | return; | |
561 | default: | |
562 | hlist_del(&obj->node); | |
aef9cb05 | 563 | raw_spin_unlock_irqrestore(&db->lock, flags); |
3ac7fe5a | 564 | free_object(obj); |
673d62cc | 565 | return; |
3ac7fe5a TG |
566 | } |
567 | out_unlock: | |
aef9cb05 | 568 | raw_spin_unlock_irqrestore(&db->lock, flags); |
3ac7fe5a TG |
569 | } |
570 | ||
b84d435c CC |
571 | /** |
572 | * debug_object_assert_init - debug checks when object should be init-ed | |
573 | * @addr: address of the object | |
574 | * @descr: pointer to an object specific debug description structure | |
575 | */ | |
576 | void debug_object_assert_init(void *addr, struct debug_obj_descr *descr) | |
577 | { | |
578 | struct debug_bucket *db; | |
579 | struct debug_obj *obj; | |
580 | unsigned long flags; | |
581 | ||
582 | if (!debug_objects_enabled) | |
583 | return; | |
584 | ||
585 | db = get_bucket((unsigned long) addr); | |
586 | ||
587 | raw_spin_lock_irqsave(&db->lock, flags); | |
588 | ||
589 | obj = lookup_object(addr, db); | |
590 | if (!obj) { | |
591 | struct debug_obj o = { .object = addr, | |
592 | .state = ODEBUG_STATE_NOTAVAILABLE, | |
593 | .descr = descr }; | |
594 | ||
595 | raw_spin_unlock_irqrestore(&db->lock, flags); | |
596 | /* | |
597 | * Maybe the object is static. Let the type specific | |
598 | * code decide what to do. | |
599 | */ | |
600 | if (debug_object_fixup(descr->fixup_assert_init, addr, | |
601 | ODEBUG_STATE_NOTAVAILABLE)) | |
602 | debug_print_object(&o, "assert_init"); | |
603 | return; | |
604 | } | |
605 | ||
606 | raw_spin_unlock_irqrestore(&db->lock, flags); | |
607 | } | |
608 | ||
a5d8e467 MD |
609 | /** |
610 | * debug_object_active_state - debug checks object usage state machine | |
611 | * @addr: address of the object | |
612 | * @descr: pointer to an object specific debug description structure | |
613 | * @expect: expected state | |
614 | * @next: state to move to if expected state is found | |
615 | */ | |
616 | void | |
617 | debug_object_active_state(void *addr, struct debug_obj_descr *descr, | |
618 | unsigned int expect, unsigned int next) | |
619 | { | |
620 | struct debug_bucket *db; | |
621 | struct debug_obj *obj; | |
622 | unsigned long flags; | |
623 | ||
624 | if (!debug_objects_enabled) | |
625 | return; | |
626 | ||
627 | db = get_bucket((unsigned long) addr); | |
628 | ||
629 | raw_spin_lock_irqsave(&db->lock, flags); | |
630 | ||
631 | obj = lookup_object(addr, db); | |
632 | if (obj) { | |
633 | switch (obj->state) { | |
634 | case ODEBUG_STATE_ACTIVE: | |
635 | if (obj->astate == expect) | |
636 | obj->astate = next; | |
637 | else | |
638 | debug_print_object(obj, "active_state"); | |
639 | break; | |
640 | ||
641 | default: | |
642 | debug_print_object(obj, "active_state"); | |
643 | break; | |
644 | } | |
645 | } else { | |
646 | struct debug_obj o = { .object = addr, | |
647 | .state = ODEBUG_STATE_NOTAVAILABLE, | |
648 | .descr = descr }; | |
649 | ||
650 | debug_print_object(&o, "active_state"); | |
651 | } | |
652 | ||
653 | raw_spin_unlock_irqrestore(&db->lock, flags); | |
654 | } | |
655 | ||
3ac7fe5a TG |
656 | #ifdef CONFIG_DEBUG_OBJECTS_FREE |
657 | static void __debug_check_no_obj_freed(const void *address, unsigned long size) | |
658 | { | |
659 | unsigned long flags, oaddr, saddr, eaddr, paddr, chunks; | |
b67bfe0d | 660 | struct hlist_node *tmp; |
673d62cc | 661 | HLIST_HEAD(freelist); |
3ac7fe5a TG |
662 | struct debug_obj_descr *descr; |
663 | enum debug_obj_state state; | |
664 | struct debug_bucket *db; | |
665 | struct debug_obj *obj; | |
666 | int cnt; | |
667 | ||
668 | saddr = (unsigned long) address; | |
669 | eaddr = saddr + size; | |
670 | paddr = saddr & ODEBUG_CHUNK_MASK; | |
671 | chunks = ((eaddr - paddr) + (ODEBUG_CHUNK_SIZE - 1)); | |
672 | chunks >>= ODEBUG_CHUNK_SHIFT; | |
673 | ||
674 | for (;chunks > 0; chunks--, paddr += ODEBUG_CHUNK_SIZE) { | |
675 | db = get_bucket(paddr); | |
676 | ||
677 | repeat: | |
678 | cnt = 0; | |
aef9cb05 | 679 | raw_spin_lock_irqsave(&db->lock, flags); |
b67bfe0d | 680 | hlist_for_each_entry_safe(obj, tmp, &db->list, node) { |
3ac7fe5a TG |
681 | cnt++; |
682 | oaddr = (unsigned long) obj->object; | |
683 | if (oaddr < saddr || oaddr >= eaddr) | |
684 | continue; | |
685 | ||
686 | switch (obj->state) { | |
687 | case ODEBUG_STATE_ACTIVE: | |
688 | debug_print_object(obj, "free"); | |
689 | descr = obj->descr; | |
690 | state = obj->state; | |
aef9cb05 | 691 | raw_spin_unlock_irqrestore(&db->lock, flags); |
3ac7fe5a TG |
692 | debug_object_fixup(descr->fixup_free, |
693 | (void *) oaddr, state); | |
694 | goto repeat; | |
695 | default: | |
696 | hlist_del(&obj->node); | |
673d62cc | 697 | hlist_add_head(&obj->node, &freelist); |
3ac7fe5a TG |
698 | break; |
699 | } | |
700 | } | |
aef9cb05 | 701 | raw_spin_unlock_irqrestore(&db->lock, flags); |
673d62cc VN |
702 | |
703 | /* Now free them */ | |
b67bfe0d | 704 | hlist_for_each_entry_safe(obj, tmp, &freelist, node) { |
673d62cc VN |
705 | hlist_del(&obj->node); |
706 | free_object(obj); | |
707 | } | |
708 | ||
3ac7fe5a TG |
709 | if (cnt > debug_objects_maxchain) |
710 | debug_objects_maxchain = cnt; | |
711 | } | |
712 | } | |
713 | ||
714 | void debug_check_no_obj_freed(const void *address, unsigned long size) | |
715 | { | |
716 | if (debug_objects_enabled) | |
717 | __debug_check_no_obj_freed(address, size); | |
718 | } | |
719 | #endif | |
720 | ||
721 | #ifdef CONFIG_DEBUG_FS | |
722 | ||
723 | static int debug_stats_show(struct seq_file *m, void *v) | |
724 | { | |
725 | seq_printf(m, "max_chain :%d\n", debug_objects_maxchain); | |
726 | seq_printf(m, "warnings :%d\n", debug_objects_warnings); | |
727 | seq_printf(m, "fixups :%d\n", debug_objects_fixups); | |
728 | seq_printf(m, "pool_free :%d\n", obj_pool_free); | |
729 | seq_printf(m, "pool_min_free :%d\n", obj_pool_min_free); | |
730 | seq_printf(m, "pool_used :%d\n", obj_pool_used); | |
731 | seq_printf(m, "pool_max_used :%d\n", obj_pool_max_used); | |
732 | return 0; | |
733 | } | |
734 | ||
735 | static int debug_stats_open(struct inode *inode, struct file *filp) | |
736 | { | |
737 | return single_open(filp, debug_stats_show, NULL); | |
738 | } | |
739 | ||
740 | static const struct file_operations debug_stats_fops = { | |
741 | .open = debug_stats_open, | |
742 | .read = seq_read, | |
743 | .llseek = seq_lseek, | |
744 | .release = single_release, | |
745 | }; | |
746 | ||
747 | static int __init debug_objects_init_debugfs(void) | |
748 | { | |
749 | struct dentry *dbgdir, *dbgstats; | |
750 | ||
751 | if (!debug_objects_enabled) | |
752 | return 0; | |
753 | ||
754 | dbgdir = debugfs_create_dir("debug_objects", NULL); | |
755 | if (!dbgdir) | |
756 | return -ENOMEM; | |
757 | ||
758 | dbgstats = debugfs_create_file("stats", 0444, dbgdir, NULL, | |
759 | &debug_stats_fops); | |
760 | if (!dbgstats) | |
761 | goto err; | |
762 | ||
763 | return 0; | |
764 | ||
765 | err: | |
766 | debugfs_remove(dbgdir); | |
767 | ||
768 | return -ENOMEM; | |
769 | } | |
770 | __initcall(debug_objects_init_debugfs); | |
771 | ||
772 | #else | |
773 | static inline void debug_objects_init_debugfs(void) { } | |
774 | #endif | |
775 | ||
776 | #ifdef CONFIG_DEBUG_OBJECTS_SELFTEST | |
777 | ||
778 | /* Random data structure for the self test */ | |
779 | struct self_test { | |
780 | unsigned long dummy1[6]; | |
781 | int static_init; | |
782 | unsigned long dummy2[3]; | |
783 | }; | |
784 | ||
785 | static __initdata struct debug_obj_descr descr_type_test; | |
786 | ||
787 | /* | |
788 | * fixup_init is called when: | |
789 | * - an active object is initialized | |
790 | */ | |
791 | static int __init fixup_init(void *addr, enum debug_obj_state state) | |
792 | { | |
793 | struct self_test *obj = addr; | |
794 | ||
795 | switch (state) { | |
796 | case ODEBUG_STATE_ACTIVE: | |
797 | debug_object_deactivate(obj, &descr_type_test); | |
798 | debug_object_init(obj, &descr_type_test); | |
799 | return 1; | |
800 | default: | |
801 | return 0; | |
802 | } | |
803 | } | |
804 | ||
805 | /* | |
806 | * fixup_activate is called when: | |
807 | * - an active object is activated | |
808 | * - an unknown object is activated (might be a statically initialized object) | |
809 | */ | |
810 | static int __init fixup_activate(void *addr, enum debug_obj_state state) | |
811 | { | |
812 | struct self_test *obj = addr; | |
813 | ||
814 | switch (state) { | |
815 | case ODEBUG_STATE_NOTAVAILABLE: | |
816 | if (obj->static_init == 1) { | |
817 | debug_object_init(obj, &descr_type_test); | |
818 | debug_object_activate(obj, &descr_type_test); | |
9f78ff00 | 819 | return 0; |
3ac7fe5a | 820 | } |
9f78ff00 | 821 | return 1; |
3ac7fe5a TG |
822 | |
823 | case ODEBUG_STATE_ACTIVE: | |
824 | debug_object_deactivate(obj, &descr_type_test); | |
825 | debug_object_activate(obj, &descr_type_test); | |
826 | return 1; | |
827 | ||
828 | default: | |
829 | return 0; | |
830 | } | |
831 | } | |
832 | ||
833 | /* | |
834 | * fixup_destroy is called when: | |
835 | * - an active object is destroyed | |
836 | */ | |
837 | static int __init fixup_destroy(void *addr, enum debug_obj_state state) | |
838 | { | |
839 | struct self_test *obj = addr; | |
840 | ||
841 | switch (state) { | |
842 | case ODEBUG_STATE_ACTIVE: | |
843 | debug_object_deactivate(obj, &descr_type_test); | |
844 | debug_object_destroy(obj, &descr_type_test); | |
845 | return 1; | |
846 | default: | |
847 | return 0; | |
848 | } | |
849 | } | |
850 | ||
851 | /* | |
852 | * fixup_free is called when: | |
853 | * - an active object is freed | |
854 | */ | |
855 | static int __init fixup_free(void *addr, enum debug_obj_state state) | |
856 | { | |
857 | struct self_test *obj = addr; | |
858 | ||
859 | switch (state) { | |
860 | case ODEBUG_STATE_ACTIVE: | |
861 | debug_object_deactivate(obj, &descr_type_test); | |
862 | debug_object_free(obj, &descr_type_test); | |
863 | return 1; | |
864 | default: | |
865 | return 0; | |
866 | } | |
867 | } | |
868 | ||
1fb2f77c | 869 | static int __init |
3ac7fe5a TG |
870 | check_results(void *addr, enum debug_obj_state state, int fixups, int warnings) |
871 | { | |
872 | struct debug_bucket *db; | |
873 | struct debug_obj *obj; | |
874 | unsigned long flags; | |
875 | int res = -EINVAL; | |
876 | ||
877 | db = get_bucket((unsigned long) addr); | |
878 | ||
aef9cb05 | 879 | raw_spin_lock_irqsave(&db->lock, flags); |
3ac7fe5a TG |
880 | |
881 | obj = lookup_object(addr, db); | |
882 | if (!obj && state != ODEBUG_STATE_NONE) { | |
5cd2b459 | 883 | WARN(1, KERN_ERR "ODEBUG: selftest object not found\n"); |
3ac7fe5a TG |
884 | goto out; |
885 | } | |
886 | if (obj && obj->state != state) { | |
5cd2b459 | 887 | WARN(1, KERN_ERR "ODEBUG: selftest wrong state: %d != %d\n", |
3ac7fe5a | 888 | obj->state, state); |
3ac7fe5a TG |
889 | goto out; |
890 | } | |
891 | if (fixups != debug_objects_fixups) { | |
5cd2b459 | 892 | WARN(1, KERN_ERR "ODEBUG: selftest fixups failed %d != %d\n", |
3ac7fe5a | 893 | fixups, debug_objects_fixups); |
3ac7fe5a TG |
894 | goto out; |
895 | } | |
896 | if (warnings != debug_objects_warnings) { | |
5cd2b459 | 897 | WARN(1, KERN_ERR "ODEBUG: selftest warnings failed %d != %d\n", |
3ac7fe5a | 898 | warnings, debug_objects_warnings); |
3ac7fe5a TG |
899 | goto out; |
900 | } | |
901 | res = 0; | |
902 | out: | |
aef9cb05 | 903 | raw_spin_unlock_irqrestore(&db->lock, flags); |
3ac7fe5a TG |
904 | if (res) |
905 | debug_objects_enabled = 0; | |
906 | return res; | |
907 | } | |
908 | ||
909 | static __initdata struct debug_obj_descr descr_type_test = { | |
910 | .name = "selftest", | |
911 | .fixup_init = fixup_init, | |
912 | .fixup_activate = fixup_activate, | |
913 | .fixup_destroy = fixup_destroy, | |
914 | .fixup_free = fixup_free, | |
915 | }; | |
916 | ||
917 | static __initdata struct self_test obj = { .static_init = 0 }; | |
918 | ||
919 | static void __init debug_objects_selftest(void) | |
920 | { | |
921 | int fixups, oldfixups, warnings, oldwarnings; | |
922 | unsigned long flags; | |
923 | ||
924 | local_irq_save(flags); | |
925 | ||
926 | fixups = oldfixups = debug_objects_fixups; | |
927 | warnings = oldwarnings = debug_objects_warnings; | |
928 | descr_test = &descr_type_test; | |
929 | ||
930 | debug_object_init(&obj, &descr_type_test); | |
931 | if (check_results(&obj, ODEBUG_STATE_INIT, fixups, warnings)) | |
932 | goto out; | |
933 | debug_object_activate(&obj, &descr_type_test); | |
934 | if (check_results(&obj, ODEBUG_STATE_ACTIVE, fixups, warnings)) | |
935 | goto out; | |
936 | debug_object_activate(&obj, &descr_type_test); | |
937 | if (check_results(&obj, ODEBUG_STATE_ACTIVE, ++fixups, ++warnings)) | |
938 | goto out; | |
939 | debug_object_deactivate(&obj, &descr_type_test); | |
940 | if (check_results(&obj, ODEBUG_STATE_INACTIVE, fixups, warnings)) | |
941 | goto out; | |
942 | debug_object_destroy(&obj, &descr_type_test); | |
943 | if (check_results(&obj, ODEBUG_STATE_DESTROYED, fixups, warnings)) | |
944 | goto out; | |
945 | debug_object_init(&obj, &descr_type_test); | |
946 | if (check_results(&obj, ODEBUG_STATE_DESTROYED, fixups, ++warnings)) | |
947 | goto out; | |
948 | debug_object_activate(&obj, &descr_type_test); | |
949 | if (check_results(&obj, ODEBUG_STATE_DESTROYED, fixups, ++warnings)) | |
950 | goto out; | |
951 | debug_object_deactivate(&obj, &descr_type_test); | |
952 | if (check_results(&obj, ODEBUG_STATE_DESTROYED, fixups, ++warnings)) | |
953 | goto out; | |
954 | debug_object_free(&obj, &descr_type_test); | |
955 | if (check_results(&obj, ODEBUG_STATE_NONE, fixups, warnings)) | |
956 | goto out; | |
957 | ||
958 | obj.static_init = 1; | |
959 | debug_object_activate(&obj, &descr_type_test); | |
9f78ff00 | 960 | if (check_results(&obj, ODEBUG_STATE_ACTIVE, fixups, warnings)) |
3ac7fe5a TG |
961 | goto out; |
962 | debug_object_init(&obj, &descr_type_test); | |
963 | if (check_results(&obj, ODEBUG_STATE_INIT, ++fixups, ++warnings)) | |
964 | goto out; | |
965 | debug_object_free(&obj, &descr_type_test); | |
966 | if (check_results(&obj, ODEBUG_STATE_NONE, fixups, warnings)) | |
967 | goto out; | |
968 | ||
969 | #ifdef CONFIG_DEBUG_OBJECTS_FREE | |
970 | debug_object_init(&obj, &descr_type_test); | |
971 | if (check_results(&obj, ODEBUG_STATE_INIT, fixups, warnings)) | |
972 | goto out; | |
973 | debug_object_activate(&obj, &descr_type_test); | |
974 | if (check_results(&obj, ODEBUG_STATE_ACTIVE, fixups, warnings)) | |
975 | goto out; | |
976 | __debug_check_no_obj_freed(&obj, sizeof(obj)); | |
977 | if (check_results(&obj, ODEBUG_STATE_NONE, ++fixups, ++warnings)) | |
978 | goto out; | |
979 | #endif | |
980 | printk(KERN_INFO "ODEBUG: selftest passed\n"); | |
981 | ||
982 | out: | |
983 | debug_objects_fixups = oldfixups; | |
984 | debug_objects_warnings = oldwarnings; | |
985 | descr_test = NULL; | |
986 | ||
987 | local_irq_restore(flags); | |
988 | } | |
989 | #else | |
990 | static inline void debug_objects_selftest(void) { } | |
991 | #endif | |
992 | ||
993 | /* | |
994 | * Called during early boot to initialize the hash buckets and link | |
995 | * the static object pool objects into the poll list. After this call | |
996 | * the object tracker is fully operational. | |
997 | */ | |
998 | void __init debug_objects_early_init(void) | |
999 | { | |
1000 | int i; | |
1001 | ||
1002 | for (i = 0; i < ODEBUG_HASH_SIZE; i++) | |
aef9cb05 | 1003 | raw_spin_lock_init(&obj_hash[i].lock); |
3ac7fe5a TG |
1004 | |
1005 | for (i = 0; i < ODEBUG_POOL_SIZE; i++) | |
1006 | hlist_add_head(&obj_static_pool[i].node, &obj_pool); | |
1007 | } | |
1008 | ||
1be1cb7b TG |
1009 | /* |
1010 | * Convert the statically allocated objects to dynamic ones: | |
1011 | */ | |
1fb2f77c | 1012 | static int __init debug_objects_replace_static_objects(void) |
1be1cb7b TG |
1013 | { |
1014 | struct debug_bucket *db = obj_hash; | |
b67bfe0d | 1015 | struct hlist_node *tmp; |
1be1cb7b TG |
1016 | struct debug_obj *obj, *new; |
1017 | HLIST_HEAD(objects); | |
1018 | int i, cnt = 0; | |
1019 | ||
1020 | for (i = 0; i < ODEBUG_POOL_SIZE; i++) { | |
1021 | obj = kmem_cache_zalloc(obj_cache, GFP_KERNEL); | |
1022 | if (!obj) | |
1023 | goto free; | |
1024 | hlist_add_head(&obj->node, &objects); | |
1025 | } | |
1026 | ||
1027 | /* | |
1028 | * When debug_objects_mem_init() is called we know that only | |
1029 | * one CPU is up, so disabling interrupts is enough | |
1030 | * protection. This avoids the lockdep hell of lock ordering. | |
1031 | */ | |
1032 | local_irq_disable(); | |
1033 | ||
1034 | /* Remove the statically allocated objects from the pool */ | |
b67bfe0d | 1035 | hlist_for_each_entry_safe(obj, tmp, &obj_pool, node) |
1be1cb7b TG |
1036 | hlist_del(&obj->node); |
1037 | /* Move the allocated objects to the pool */ | |
1038 | hlist_move_list(&objects, &obj_pool); | |
1039 | ||
1040 | /* Replace the active object references */ | |
1041 | for (i = 0; i < ODEBUG_HASH_SIZE; i++, db++) { | |
1042 | hlist_move_list(&db->list, &objects); | |
1043 | ||
b67bfe0d | 1044 | hlist_for_each_entry(obj, &objects, node) { |
1be1cb7b TG |
1045 | new = hlist_entry(obj_pool.first, typeof(*obj), node); |
1046 | hlist_del(&new->node); | |
1047 | /* copy object data */ | |
1048 | *new = *obj; | |
1049 | hlist_add_head(&new->node, &db->list); | |
1050 | cnt++; | |
1051 | } | |
1052 | } | |
765a5e0c | 1053 | local_irq_enable(); |
1be1cb7b TG |
1054 | |
1055 | printk(KERN_DEBUG "ODEBUG: %d of %d active objects replaced\n", cnt, | |
1056 | obj_pool_used); | |
1be1cb7b TG |
1057 | return 0; |
1058 | free: | |
b67bfe0d | 1059 | hlist_for_each_entry_safe(obj, tmp, &objects, node) { |
1be1cb7b TG |
1060 | hlist_del(&obj->node); |
1061 | kmem_cache_free(obj_cache, obj); | |
1062 | } | |
1063 | return -ENOMEM; | |
1064 | } | |
1065 | ||
3ac7fe5a TG |
1066 | /* |
1067 | * Called after the kmem_caches are functional to setup a dedicated | |
1068 | * cache pool, which has the SLAB_DEBUG_OBJECTS flag set. This flag | |
1069 | * prevents that the debug code is called on kmem_cache_free() for the | |
1070 | * debug tracker objects to avoid recursive calls. | |
1071 | */ | |
1072 | void __init debug_objects_mem_init(void) | |
1073 | { | |
1074 | if (!debug_objects_enabled) | |
1075 | return; | |
1076 | ||
1077 | obj_cache = kmem_cache_create("debug_objects_cache", | |
1078 | sizeof (struct debug_obj), 0, | |
1079 | SLAB_DEBUG_OBJECTS, NULL); | |
1080 | ||
1be1cb7b | 1081 | if (!obj_cache || debug_objects_replace_static_objects()) { |
3ac7fe5a | 1082 | debug_objects_enabled = 0; |
1be1cb7b TG |
1083 | if (obj_cache) |
1084 | kmem_cache_destroy(obj_cache); | |
1085 | printk(KERN_WARNING "ODEBUG: out of memory.\n"); | |
1086 | } else | |
3ac7fe5a TG |
1087 | debug_objects_selftest(); |
1088 | } |