blob: 90e46fa12721ec9fbbf675f518039efb1876bcdb [file] [log] [blame]
Thomas Gleixner3ac7fe52008-04-30 00:55:01 -07001/*
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>
12#include <linux/seq_file.h>
13#include <linux/debugfs.h>
14#include <linux/hash.h>
15
16#define ODEBUG_HASH_BITS 14
17#define ODEBUG_HASH_SIZE (1 << ODEBUG_HASH_BITS)
18
19#define ODEBUG_POOL_SIZE 512
20#define ODEBUG_POOL_MIN_LEVEL 256
21
22#define ODEBUG_CHUNK_SHIFT PAGE_SHIFT
23#define ODEBUG_CHUNK_SIZE (1 << ODEBUG_CHUNK_SHIFT)
24#define ODEBUG_CHUNK_MASK (~(ODEBUG_CHUNK_SIZE - 1))
25
26struct debug_bucket {
27 struct hlist_head list;
28 spinlock_t lock;
29};
30
31static struct debug_bucket obj_hash[ODEBUG_HASH_SIZE];
32
33static struct debug_obj obj_static_pool[ODEBUG_POOL_SIZE];
34
35static DEFINE_SPINLOCK(pool_lock);
36
37static HLIST_HEAD(obj_pool);
38
39static int obj_pool_min_free = ODEBUG_POOL_SIZE;
40static int obj_pool_free = ODEBUG_POOL_SIZE;
41static int obj_pool_used;
42static int obj_pool_max_used;
43static struct kmem_cache *obj_cache;
44
45static int debug_objects_maxchain __read_mostly;
46static int debug_objects_fixups __read_mostly;
47static int debug_objects_warnings __read_mostly;
Ingo Molnar3ae70202008-11-26 10:02:00 +010048static int debug_objects_enabled __read_mostly
49 = CONFIG_DEBUG_OBJECTS_ENABLE_DEFAULT;
50
Thomas Gleixner3ac7fe52008-04-30 00:55:01 -070051static struct debug_obj_descr *descr_test __read_mostly;
52
53static int __init enable_object_debug(char *str)
54{
55 debug_objects_enabled = 1;
56 return 0;
57}
Kyle McMartin3e8ebb52009-03-01 20:41:41 -050058
59static int __init disable_object_debug(char *str)
60{
61 debug_objects_enabled = 0;
62 return 0;
63}
64
Thomas Gleixner3ac7fe52008-04-30 00:55:01 -070065early_param("debug_objects", enable_object_debug);
Kyle McMartin3e8ebb52009-03-01 20:41:41 -050066early_param("no_debug_objects", disable_object_debug);
Thomas Gleixner3ac7fe52008-04-30 00:55:01 -070067
68static const char *obj_states[ODEBUG_STATE_MAX] = {
69 [ODEBUG_STATE_NONE] = "none",
70 [ODEBUG_STATE_INIT] = "initialized",
71 [ODEBUG_STATE_INACTIVE] = "inactive",
72 [ODEBUG_STATE_ACTIVE] = "active",
73 [ODEBUG_STATE_DESTROYED] = "destroyed",
74 [ODEBUG_STATE_NOTAVAILABLE] = "not available",
75};
76
77static int fill_pool(void)
78{
79 gfp_t gfp = GFP_ATOMIC | __GFP_NORETRY | __GFP_NOWARN;
80 struct debug_obj *new;
Vegard Nossum50db04dd2008-06-15 00:47:36 +020081 unsigned long flags;
Thomas Gleixner3ac7fe52008-04-30 00:55:01 -070082
83 if (likely(obj_pool_free >= ODEBUG_POOL_MIN_LEVEL))
84 return obj_pool_free;
85
86 if (unlikely(!obj_cache))
87 return obj_pool_free;
88
89 while (obj_pool_free < ODEBUG_POOL_MIN_LEVEL) {
90
91 new = kmem_cache_zalloc(obj_cache, gfp);
92 if (!new)
93 return obj_pool_free;
94
Vegard Nossum50db04dd2008-06-15 00:47:36 +020095 spin_lock_irqsave(&pool_lock, flags);
Thomas Gleixner3ac7fe52008-04-30 00:55:01 -070096 hlist_add_head(&new->node, &obj_pool);
97 obj_pool_free++;
Vegard Nossum50db04dd2008-06-15 00:47:36 +020098 spin_unlock_irqrestore(&pool_lock, flags);
Thomas Gleixner3ac7fe52008-04-30 00:55:01 -070099 }
100 return obj_pool_free;
101}
102
103/*
104 * Lookup an object in the hash bucket.
105 */
106static struct debug_obj *lookup_object(void *addr, struct debug_bucket *b)
107{
108 struct hlist_node *node;
109 struct debug_obj *obj;
110 int cnt = 0;
111
112 hlist_for_each_entry(obj, node, &b->list, node) {
113 cnt++;
114 if (obj->object == addr)
115 return obj;
116 }
117 if (cnt > debug_objects_maxchain)
118 debug_objects_maxchain = cnt;
119
120 return NULL;
121}
122
123/*
Vegard Nossum50db04dd2008-06-15 00:47:36 +0200124 * Allocate a new object. If the pool is empty, switch off the debugger.
Vegard Nossum673d62cc2008-08-31 23:39:21 +0200125 * Must be called with interrupts disabled.
Thomas Gleixner3ac7fe52008-04-30 00:55:01 -0700126 */
127static struct debug_obj *
128alloc_object(void *addr, struct debug_bucket *b, struct debug_obj_descr *descr)
129{
130 struct debug_obj *obj = NULL;
Thomas Gleixner3ac7fe52008-04-30 00:55:01 -0700131
Thomas Gleixner3ac7fe52008-04-30 00:55:01 -0700132 spin_lock(&pool_lock);
133 if (obj_pool.first) {
134 obj = hlist_entry(obj_pool.first, typeof(*obj), node);
135
136 obj->object = addr;
137 obj->descr = descr;
138 obj->state = ODEBUG_STATE_NONE;
139 hlist_del(&obj->node);
140
141 hlist_add_head(&obj->node, &b->list);
142
143 obj_pool_used++;
144 if (obj_pool_used > obj_pool_max_used)
145 obj_pool_max_used = obj_pool_used;
146
147 obj_pool_free--;
148 if (obj_pool_free < obj_pool_min_free)
149 obj_pool_min_free = obj_pool_free;
150 }
151 spin_unlock(&pool_lock);
152
Thomas Gleixner3ac7fe52008-04-30 00:55:01 -0700153 return obj;
154}
155
156/*
157 * Put the object back into the pool or give it back to kmem_cache:
158 */
159static void free_object(struct debug_obj *obj)
160{
161 unsigned long idx = (unsigned long)(obj - obj_static_pool);
Vegard Nossum673d62cc2008-08-31 23:39:21 +0200162 unsigned long flags;
Thomas Gleixner3ac7fe52008-04-30 00:55:01 -0700163
164 if (obj_pool_free < ODEBUG_POOL_SIZE || idx < ODEBUG_POOL_SIZE) {
Vegard Nossum673d62cc2008-08-31 23:39:21 +0200165 spin_lock_irqsave(&pool_lock, flags);
Thomas Gleixner3ac7fe52008-04-30 00:55:01 -0700166 hlist_add_head(&obj->node, &obj_pool);
167 obj_pool_free++;
168 obj_pool_used--;
Vegard Nossum673d62cc2008-08-31 23:39:21 +0200169 spin_unlock_irqrestore(&pool_lock, flags);
Thomas Gleixner3ac7fe52008-04-30 00:55:01 -0700170 } else {
Vegard Nossum673d62cc2008-08-31 23:39:21 +0200171 spin_lock_irqsave(&pool_lock, flags);
Thomas Gleixner3ac7fe52008-04-30 00:55:01 -0700172 obj_pool_used--;
Vegard Nossum673d62cc2008-08-31 23:39:21 +0200173 spin_unlock_irqrestore(&pool_lock, flags);
Thomas Gleixner3ac7fe52008-04-30 00:55:01 -0700174 kmem_cache_free(obj_cache, obj);
175 }
176}
177
178/*
179 * We run out of memory. That means we probably have tons of objects
180 * allocated.
181 */
182static void debug_objects_oom(void)
183{
184 struct debug_bucket *db = obj_hash;
185 struct hlist_node *node, *tmp;
Vegard Nossum673d62cc2008-08-31 23:39:21 +0200186 HLIST_HEAD(freelist);
Thomas Gleixner3ac7fe52008-04-30 00:55:01 -0700187 struct debug_obj *obj;
188 unsigned long flags;
189 int i;
190
191 printk(KERN_WARNING "ODEBUG: Out of memory. ODEBUG disabled\n");
192
193 for (i = 0; i < ODEBUG_HASH_SIZE; i++, db++) {
194 spin_lock_irqsave(&db->lock, flags);
Vegard Nossum673d62cc2008-08-31 23:39:21 +0200195 hlist_move_list(&db->list, &freelist);
196 spin_unlock_irqrestore(&db->lock, flags);
197
198 /* Now free them */
199 hlist_for_each_entry_safe(obj, node, tmp, &freelist, node) {
Thomas Gleixner3ac7fe52008-04-30 00:55:01 -0700200 hlist_del(&obj->node);
201 free_object(obj);
202 }
Thomas Gleixner3ac7fe52008-04-30 00:55:01 -0700203 }
204}
205
206/*
207 * We use the pfn of the address for the hash. That way we can check
208 * for freed objects simply by checking the affected bucket.
209 */
210static struct debug_bucket *get_bucket(unsigned long addr)
211{
212 unsigned long hash;
213
214 hash = hash_long((addr >> ODEBUG_CHUNK_SHIFT), ODEBUG_HASH_BITS);
215 return &obj_hash[hash];
216}
217
218static void debug_print_object(struct debug_obj *obj, char *msg)
219{
220 static int limit;
221
222 if (limit < 5 && obj->descr != descr_test) {
223 limit++;
Arjan van de Ven5cd2b452008-07-25 19:45:39 -0700224 WARN(1, KERN_ERR "ODEBUG: %s %s object type: %s\n", msg,
Thomas Gleixner3ac7fe52008-04-30 00:55:01 -0700225 obj_states[obj->state], obj->descr->name);
Thomas Gleixner3ac7fe52008-04-30 00:55:01 -0700226 }
227 debug_objects_warnings++;
228}
229
230/*
231 * Try to repair the damage, so we have a better chance to get useful
232 * debug output.
233 */
234static void
235debug_object_fixup(int (*fixup)(void *addr, enum debug_obj_state state),
236 void * addr, enum debug_obj_state state)
237{
238 if (fixup)
239 debug_objects_fixups += fixup(addr, state);
240}
241
242static void debug_object_is_on_stack(void *addr, int onstack)
243{
Thomas Gleixner3ac7fe52008-04-30 00:55:01 -0700244 int is_on_stack;
245 static int limit;
246
247 if (limit > 4)
248 return;
249
FUJITA Tomonori8b05c7e2008-07-23 21:26:53 -0700250 is_on_stack = object_is_on_stack(addr);
Thomas Gleixner3ac7fe52008-04-30 00:55:01 -0700251 if (is_on_stack == onstack)
252 return;
253
254 limit++;
255 if (is_on_stack)
256 printk(KERN_WARNING
257 "ODEBUG: object is on stack, but not annotated\n");
258 else
259 printk(KERN_WARNING
260 "ODEBUG: object is not on stack, but annotated\n");
261 WARN_ON(1);
262}
263
264static void
265__debug_object_init(void *addr, struct debug_obj_descr *descr, int onstack)
266{
267 enum debug_obj_state state;
268 struct debug_bucket *db;
269 struct debug_obj *obj;
270 unsigned long flags;
271
Vegard Nossum50db04dd2008-06-15 00:47:36 +0200272 fill_pool();
273
Thomas Gleixner3ac7fe52008-04-30 00:55:01 -0700274 db = get_bucket((unsigned long) addr);
275
276 spin_lock_irqsave(&db->lock, flags);
277
278 obj = lookup_object(addr, db);
279 if (!obj) {
280 obj = alloc_object(addr, db, descr);
281 if (!obj) {
282 debug_objects_enabled = 0;
283 spin_unlock_irqrestore(&db->lock, flags);
284 debug_objects_oom();
285 return;
286 }
287 debug_object_is_on_stack(addr, onstack);
288 }
289
290 switch (obj->state) {
291 case ODEBUG_STATE_NONE:
292 case ODEBUG_STATE_INIT:
293 case ODEBUG_STATE_INACTIVE:
294 obj->state = ODEBUG_STATE_INIT;
295 break;
296
297 case ODEBUG_STATE_ACTIVE:
298 debug_print_object(obj, "init");
299 state = obj->state;
300 spin_unlock_irqrestore(&db->lock, flags);
301 debug_object_fixup(descr->fixup_init, addr, state);
302 return;
303
304 case ODEBUG_STATE_DESTROYED:
305 debug_print_object(obj, "init");
306 break;
307 default:
308 break;
309 }
310
311 spin_unlock_irqrestore(&db->lock, flags);
312}
313
314/**
315 * debug_object_init - debug checks when an object is initialized
316 * @addr: address of the object
317 * @descr: pointer to an object specific debug description structure
318 */
319void debug_object_init(void *addr, struct debug_obj_descr *descr)
320{
321 if (!debug_objects_enabled)
322 return;
323
324 __debug_object_init(addr, descr, 0);
325}
326
327/**
328 * debug_object_init_on_stack - debug checks when an object on stack is
329 * initialized
330 * @addr: address of the object
331 * @descr: pointer to an object specific debug description structure
332 */
333void debug_object_init_on_stack(void *addr, struct debug_obj_descr *descr)
334{
335 if (!debug_objects_enabled)
336 return;
337
338 __debug_object_init(addr, descr, 1);
339}
340
341/**
342 * debug_object_activate - debug checks when an object is activated
343 * @addr: address of the object
344 * @descr: pointer to an object specific debug description structure
345 */
346void debug_object_activate(void *addr, struct debug_obj_descr *descr)
347{
348 enum debug_obj_state state;
349 struct debug_bucket *db;
350 struct debug_obj *obj;
351 unsigned long flags;
352
353 if (!debug_objects_enabled)
354 return;
355
356 db = get_bucket((unsigned long) addr);
357
358 spin_lock_irqsave(&db->lock, flags);
359
360 obj = lookup_object(addr, db);
361 if (obj) {
362 switch (obj->state) {
363 case ODEBUG_STATE_INIT:
364 case ODEBUG_STATE_INACTIVE:
365 obj->state = ODEBUG_STATE_ACTIVE;
366 break;
367
368 case ODEBUG_STATE_ACTIVE:
369 debug_print_object(obj, "activate");
370 state = obj->state;
371 spin_unlock_irqrestore(&db->lock, flags);
372 debug_object_fixup(descr->fixup_activate, addr, state);
373 return;
374
375 case ODEBUG_STATE_DESTROYED:
376 debug_print_object(obj, "activate");
377 break;
378 default:
379 break;
380 }
381 spin_unlock_irqrestore(&db->lock, flags);
382 return;
383 }
384
385 spin_unlock_irqrestore(&db->lock, flags);
386 /*
387 * This happens when a static object is activated. We
388 * let the type specific code decide whether this is
389 * true or not.
390 */
391 debug_object_fixup(descr->fixup_activate, addr,
392 ODEBUG_STATE_NOTAVAILABLE);
393}
394
395/**
396 * debug_object_deactivate - debug checks when an object is deactivated
397 * @addr: address of the object
398 * @descr: pointer to an object specific debug description structure
399 */
400void debug_object_deactivate(void *addr, struct debug_obj_descr *descr)
401{
402 struct debug_bucket *db;
403 struct debug_obj *obj;
404 unsigned long flags;
405
406 if (!debug_objects_enabled)
407 return;
408
409 db = get_bucket((unsigned long) addr);
410
411 spin_lock_irqsave(&db->lock, flags);
412
413 obj = lookup_object(addr, db);
414 if (obj) {
415 switch (obj->state) {
416 case ODEBUG_STATE_INIT:
417 case ODEBUG_STATE_INACTIVE:
418 case ODEBUG_STATE_ACTIVE:
419 obj->state = ODEBUG_STATE_INACTIVE;
420 break;
421
422 case ODEBUG_STATE_DESTROYED:
423 debug_print_object(obj, "deactivate");
424 break;
425 default:
426 break;
427 }
428 } else {
429 struct debug_obj o = { .object = addr,
430 .state = ODEBUG_STATE_NOTAVAILABLE,
431 .descr = descr };
432
433 debug_print_object(&o, "deactivate");
434 }
435
436 spin_unlock_irqrestore(&db->lock, flags);
437}
438
439/**
440 * debug_object_destroy - debug checks when an object is destroyed
441 * @addr: address of the object
442 * @descr: pointer to an object specific debug description structure
443 */
444void debug_object_destroy(void *addr, struct debug_obj_descr *descr)
445{
446 enum debug_obj_state state;
447 struct debug_bucket *db;
448 struct debug_obj *obj;
449 unsigned long flags;
450
451 if (!debug_objects_enabled)
452 return;
453
454 db = get_bucket((unsigned long) addr);
455
456 spin_lock_irqsave(&db->lock, flags);
457
458 obj = lookup_object(addr, db);
459 if (!obj)
460 goto out_unlock;
461
462 switch (obj->state) {
463 case ODEBUG_STATE_NONE:
464 case ODEBUG_STATE_INIT:
465 case ODEBUG_STATE_INACTIVE:
466 obj->state = ODEBUG_STATE_DESTROYED;
467 break;
468 case ODEBUG_STATE_ACTIVE:
469 debug_print_object(obj, "destroy");
470 state = obj->state;
471 spin_unlock_irqrestore(&db->lock, flags);
472 debug_object_fixup(descr->fixup_destroy, addr, state);
473 return;
474
475 case ODEBUG_STATE_DESTROYED:
476 debug_print_object(obj, "destroy");
477 break;
478 default:
479 break;
480 }
481out_unlock:
482 spin_unlock_irqrestore(&db->lock, flags);
483}
484
485/**
486 * debug_object_free - debug checks when an object is freed
487 * @addr: address of the object
488 * @descr: pointer to an object specific debug description structure
489 */
490void debug_object_free(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
502 spin_lock_irqsave(&db->lock, flags);
503
504 obj = lookup_object(addr, db);
505 if (!obj)
506 goto out_unlock;
507
508 switch (obj->state) {
509 case ODEBUG_STATE_ACTIVE:
510 debug_print_object(obj, "free");
511 state = obj->state;
512 spin_unlock_irqrestore(&db->lock, flags);
513 debug_object_fixup(descr->fixup_free, addr, state);
514 return;
515 default:
516 hlist_del(&obj->node);
Vegard Nossum673d62cc2008-08-31 23:39:21 +0200517 spin_unlock_irqrestore(&db->lock, flags);
Thomas Gleixner3ac7fe52008-04-30 00:55:01 -0700518 free_object(obj);
Vegard Nossum673d62cc2008-08-31 23:39:21 +0200519 return;
Thomas Gleixner3ac7fe52008-04-30 00:55:01 -0700520 }
521out_unlock:
522 spin_unlock_irqrestore(&db->lock, flags);
523}
524
525#ifdef CONFIG_DEBUG_OBJECTS_FREE
526static void __debug_check_no_obj_freed(const void *address, unsigned long size)
527{
528 unsigned long flags, oaddr, saddr, eaddr, paddr, chunks;
529 struct hlist_node *node, *tmp;
Vegard Nossum673d62cc2008-08-31 23:39:21 +0200530 HLIST_HEAD(freelist);
Thomas Gleixner3ac7fe52008-04-30 00:55:01 -0700531 struct debug_obj_descr *descr;
532 enum debug_obj_state state;
533 struct debug_bucket *db;
534 struct debug_obj *obj;
535 int cnt;
536
537 saddr = (unsigned long) address;
538 eaddr = saddr + size;
539 paddr = saddr & ODEBUG_CHUNK_MASK;
540 chunks = ((eaddr - paddr) + (ODEBUG_CHUNK_SIZE - 1));
541 chunks >>= ODEBUG_CHUNK_SHIFT;
542
543 for (;chunks > 0; chunks--, paddr += ODEBUG_CHUNK_SIZE) {
544 db = get_bucket(paddr);
545
546repeat:
547 cnt = 0;
548 spin_lock_irqsave(&db->lock, flags);
549 hlist_for_each_entry_safe(obj, node, tmp, &db->list, node) {
550 cnt++;
551 oaddr = (unsigned long) obj->object;
552 if (oaddr < saddr || oaddr >= eaddr)
553 continue;
554
555 switch (obj->state) {
556 case ODEBUG_STATE_ACTIVE:
557 debug_print_object(obj, "free");
558 descr = obj->descr;
559 state = obj->state;
560 spin_unlock_irqrestore(&db->lock, flags);
561 debug_object_fixup(descr->fixup_free,
562 (void *) oaddr, state);
563 goto repeat;
564 default:
565 hlist_del(&obj->node);
Vegard Nossum673d62cc2008-08-31 23:39:21 +0200566 hlist_add_head(&obj->node, &freelist);
Thomas Gleixner3ac7fe52008-04-30 00:55:01 -0700567 break;
568 }
569 }
570 spin_unlock_irqrestore(&db->lock, flags);
Vegard Nossum673d62cc2008-08-31 23:39:21 +0200571
572 /* Now free them */
573 hlist_for_each_entry_safe(obj, node, tmp, &freelist, node) {
574 hlist_del(&obj->node);
575 free_object(obj);
576 }
577
Thomas Gleixner3ac7fe52008-04-30 00:55:01 -0700578 if (cnt > debug_objects_maxchain)
579 debug_objects_maxchain = cnt;
580 }
581}
582
583void debug_check_no_obj_freed(const void *address, unsigned long size)
584{
585 if (debug_objects_enabled)
586 __debug_check_no_obj_freed(address, size);
587}
588#endif
589
590#ifdef CONFIG_DEBUG_FS
591
592static int debug_stats_show(struct seq_file *m, void *v)
593{
594 seq_printf(m, "max_chain :%d\n", debug_objects_maxchain);
595 seq_printf(m, "warnings :%d\n", debug_objects_warnings);
596 seq_printf(m, "fixups :%d\n", debug_objects_fixups);
597 seq_printf(m, "pool_free :%d\n", obj_pool_free);
598 seq_printf(m, "pool_min_free :%d\n", obj_pool_min_free);
599 seq_printf(m, "pool_used :%d\n", obj_pool_used);
600 seq_printf(m, "pool_max_used :%d\n", obj_pool_max_used);
601 return 0;
602}
603
604static int debug_stats_open(struct inode *inode, struct file *filp)
605{
606 return single_open(filp, debug_stats_show, NULL);
607}
608
609static const struct file_operations debug_stats_fops = {
610 .open = debug_stats_open,
611 .read = seq_read,
612 .llseek = seq_lseek,
613 .release = single_release,
614};
615
616static int __init debug_objects_init_debugfs(void)
617{
618 struct dentry *dbgdir, *dbgstats;
619
620 if (!debug_objects_enabled)
621 return 0;
622
623 dbgdir = debugfs_create_dir("debug_objects", NULL);
624 if (!dbgdir)
625 return -ENOMEM;
626
627 dbgstats = debugfs_create_file("stats", 0444, dbgdir, NULL,
628 &debug_stats_fops);
629 if (!dbgstats)
630 goto err;
631
632 return 0;
633
634err:
635 debugfs_remove(dbgdir);
636
637 return -ENOMEM;
638}
639__initcall(debug_objects_init_debugfs);
640
641#else
642static inline void debug_objects_init_debugfs(void) { }
643#endif
644
645#ifdef CONFIG_DEBUG_OBJECTS_SELFTEST
646
647/* Random data structure for the self test */
648struct self_test {
649 unsigned long dummy1[6];
650 int static_init;
651 unsigned long dummy2[3];
652};
653
654static __initdata struct debug_obj_descr descr_type_test;
655
656/*
657 * fixup_init is called when:
658 * - an active object is initialized
659 */
660static int __init fixup_init(void *addr, enum debug_obj_state state)
661{
662 struct self_test *obj = addr;
663
664 switch (state) {
665 case ODEBUG_STATE_ACTIVE:
666 debug_object_deactivate(obj, &descr_type_test);
667 debug_object_init(obj, &descr_type_test);
668 return 1;
669 default:
670 return 0;
671 }
672}
673
674/*
675 * fixup_activate is called when:
676 * - an active object is activated
677 * - an unknown object is activated (might be a statically initialized object)
678 */
679static int __init fixup_activate(void *addr, enum debug_obj_state state)
680{
681 struct self_test *obj = addr;
682
683 switch (state) {
684 case ODEBUG_STATE_NOTAVAILABLE:
685 if (obj->static_init == 1) {
686 debug_object_init(obj, &descr_type_test);
687 debug_object_activate(obj, &descr_type_test);
688 /*
689 * Real code should return 0 here ! This is
690 * not a fixup of some bad behaviour. We
691 * merily call the debug_init function to keep
692 * track of the object.
693 */
694 return 1;
695 } else {
696 /* Real code needs to emit a warning here */
697 }
698 return 0;
699
700 case ODEBUG_STATE_ACTIVE:
701 debug_object_deactivate(obj, &descr_type_test);
702 debug_object_activate(obj, &descr_type_test);
703 return 1;
704
705 default:
706 return 0;
707 }
708}
709
710/*
711 * fixup_destroy is called when:
712 * - an active object is destroyed
713 */
714static int __init fixup_destroy(void *addr, enum debug_obj_state state)
715{
716 struct self_test *obj = addr;
717
718 switch (state) {
719 case ODEBUG_STATE_ACTIVE:
720 debug_object_deactivate(obj, &descr_type_test);
721 debug_object_destroy(obj, &descr_type_test);
722 return 1;
723 default:
724 return 0;
725 }
726}
727
728/*
729 * fixup_free is called when:
730 * - an active object is freed
731 */
732static int __init fixup_free(void *addr, enum debug_obj_state state)
733{
734 struct self_test *obj = addr;
735
736 switch (state) {
737 case ODEBUG_STATE_ACTIVE:
738 debug_object_deactivate(obj, &descr_type_test);
739 debug_object_free(obj, &descr_type_test);
740 return 1;
741 default:
742 return 0;
743 }
744}
745
746static int
747check_results(void *addr, enum debug_obj_state state, int fixups, int warnings)
748{
749 struct debug_bucket *db;
750 struct debug_obj *obj;
751 unsigned long flags;
752 int res = -EINVAL;
753
754 db = get_bucket((unsigned long) addr);
755
756 spin_lock_irqsave(&db->lock, flags);
757
758 obj = lookup_object(addr, db);
759 if (!obj && state != ODEBUG_STATE_NONE) {
Arjan van de Ven5cd2b452008-07-25 19:45:39 -0700760 WARN(1, KERN_ERR "ODEBUG: selftest object not found\n");
Thomas Gleixner3ac7fe52008-04-30 00:55:01 -0700761 goto out;
762 }
763 if (obj && obj->state != state) {
Arjan van de Ven5cd2b452008-07-25 19:45:39 -0700764 WARN(1, KERN_ERR "ODEBUG: selftest wrong state: %d != %d\n",
Thomas Gleixner3ac7fe52008-04-30 00:55:01 -0700765 obj->state, state);
Thomas Gleixner3ac7fe52008-04-30 00:55:01 -0700766 goto out;
767 }
768 if (fixups != debug_objects_fixups) {
Arjan van de Ven5cd2b452008-07-25 19:45:39 -0700769 WARN(1, KERN_ERR "ODEBUG: selftest fixups failed %d != %d\n",
Thomas Gleixner3ac7fe52008-04-30 00:55:01 -0700770 fixups, debug_objects_fixups);
Thomas Gleixner3ac7fe52008-04-30 00:55:01 -0700771 goto out;
772 }
773 if (warnings != debug_objects_warnings) {
Arjan van de Ven5cd2b452008-07-25 19:45:39 -0700774 WARN(1, KERN_ERR "ODEBUG: selftest warnings failed %d != %d\n",
Thomas Gleixner3ac7fe52008-04-30 00:55:01 -0700775 warnings, debug_objects_warnings);
Thomas Gleixner3ac7fe52008-04-30 00:55:01 -0700776 goto out;
777 }
778 res = 0;
779out:
780 spin_unlock_irqrestore(&db->lock, flags);
781 if (res)
782 debug_objects_enabled = 0;
783 return res;
784}
785
786static __initdata struct debug_obj_descr descr_type_test = {
787 .name = "selftest",
788 .fixup_init = fixup_init,
789 .fixup_activate = fixup_activate,
790 .fixup_destroy = fixup_destroy,
791 .fixup_free = fixup_free,
792};
793
794static __initdata struct self_test obj = { .static_init = 0 };
795
796static void __init debug_objects_selftest(void)
797{
798 int fixups, oldfixups, warnings, oldwarnings;
799 unsigned long flags;
800
801 local_irq_save(flags);
802
803 fixups = oldfixups = debug_objects_fixups;
804 warnings = oldwarnings = debug_objects_warnings;
805 descr_test = &descr_type_test;
806
807 debug_object_init(&obj, &descr_type_test);
808 if (check_results(&obj, ODEBUG_STATE_INIT, fixups, warnings))
809 goto out;
810 debug_object_activate(&obj, &descr_type_test);
811 if (check_results(&obj, ODEBUG_STATE_ACTIVE, fixups, warnings))
812 goto out;
813 debug_object_activate(&obj, &descr_type_test);
814 if (check_results(&obj, ODEBUG_STATE_ACTIVE, ++fixups, ++warnings))
815 goto out;
816 debug_object_deactivate(&obj, &descr_type_test);
817 if (check_results(&obj, ODEBUG_STATE_INACTIVE, fixups, warnings))
818 goto out;
819 debug_object_destroy(&obj, &descr_type_test);
820 if (check_results(&obj, ODEBUG_STATE_DESTROYED, fixups, warnings))
821 goto out;
822 debug_object_init(&obj, &descr_type_test);
823 if (check_results(&obj, ODEBUG_STATE_DESTROYED, fixups, ++warnings))
824 goto out;
825 debug_object_activate(&obj, &descr_type_test);
826 if (check_results(&obj, ODEBUG_STATE_DESTROYED, fixups, ++warnings))
827 goto out;
828 debug_object_deactivate(&obj, &descr_type_test);
829 if (check_results(&obj, ODEBUG_STATE_DESTROYED, fixups, ++warnings))
830 goto out;
831 debug_object_free(&obj, &descr_type_test);
832 if (check_results(&obj, ODEBUG_STATE_NONE, fixups, warnings))
833 goto out;
834
835 obj.static_init = 1;
836 debug_object_activate(&obj, &descr_type_test);
837 if (check_results(&obj, ODEBUG_STATE_ACTIVE, ++fixups, warnings))
838 goto out;
839 debug_object_init(&obj, &descr_type_test);
840 if (check_results(&obj, ODEBUG_STATE_INIT, ++fixups, ++warnings))
841 goto out;
842 debug_object_free(&obj, &descr_type_test);
843 if (check_results(&obj, ODEBUG_STATE_NONE, fixups, warnings))
844 goto out;
845
846#ifdef CONFIG_DEBUG_OBJECTS_FREE
847 debug_object_init(&obj, &descr_type_test);
848 if (check_results(&obj, ODEBUG_STATE_INIT, fixups, warnings))
849 goto out;
850 debug_object_activate(&obj, &descr_type_test);
851 if (check_results(&obj, ODEBUG_STATE_ACTIVE, fixups, warnings))
852 goto out;
853 __debug_check_no_obj_freed(&obj, sizeof(obj));
854 if (check_results(&obj, ODEBUG_STATE_NONE, ++fixups, ++warnings))
855 goto out;
856#endif
857 printk(KERN_INFO "ODEBUG: selftest passed\n");
858
859out:
860 debug_objects_fixups = oldfixups;
861 debug_objects_warnings = oldwarnings;
862 descr_test = NULL;
863
864 local_irq_restore(flags);
865}
866#else
867static inline void debug_objects_selftest(void) { }
868#endif
869
870/*
871 * Called during early boot to initialize the hash buckets and link
872 * the static object pool objects into the poll list. After this call
873 * the object tracker is fully operational.
874 */
875void __init debug_objects_early_init(void)
876{
877 int i;
878
879 for (i = 0; i < ODEBUG_HASH_SIZE; i++)
880 spin_lock_init(&obj_hash[i].lock);
881
882 for (i = 0; i < ODEBUG_POOL_SIZE; i++)
883 hlist_add_head(&obj_static_pool[i].node, &obj_pool);
884}
885
886/*
887 * Called after the kmem_caches are functional to setup a dedicated
888 * cache pool, which has the SLAB_DEBUG_OBJECTS flag set. This flag
889 * prevents that the debug code is called on kmem_cache_free() for the
890 * debug tracker objects to avoid recursive calls.
891 */
892void __init debug_objects_mem_init(void)
893{
894 if (!debug_objects_enabled)
895 return;
896
897 obj_cache = kmem_cache_create("debug_objects_cache",
898 sizeof (struct debug_obj), 0,
899 SLAB_DEBUG_OBJECTS, NULL);
900
901 if (!obj_cache)
902 debug_objects_enabled = 0;
903 else
904 debug_objects_selftest();
905}