blob: e3ab374e1334ab80fc172c3d256d2eb4fddd665e [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;
48static int debug_objects_enabled __read_mostly;
49static struct debug_obj_descr *descr_test __read_mostly;
50
51static int __init enable_object_debug(char *str)
52{
53 debug_objects_enabled = 1;
54 return 0;
55}
56early_param("debug_objects", enable_object_debug);
57
58static const char *obj_states[ODEBUG_STATE_MAX] = {
59 [ODEBUG_STATE_NONE] = "none",
60 [ODEBUG_STATE_INIT] = "initialized",
61 [ODEBUG_STATE_INACTIVE] = "inactive",
62 [ODEBUG_STATE_ACTIVE] = "active",
63 [ODEBUG_STATE_DESTROYED] = "destroyed",
64 [ODEBUG_STATE_NOTAVAILABLE] = "not available",
65};
66
67static int fill_pool(void)
68{
69 gfp_t gfp = GFP_ATOMIC | __GFP_NORETRY | __GFP_NOWARN;
70 struct debug_obj *new;
Vegard Nossum50db04dd2008-06-15 00:47:36 +020071 unsigned long flags;
Thomas Gleixner3ac7fe52008-04-30 00:55:01 -070072
73 if (likely(obj_pool_free >= ODEBUG_POOL_MIN_LEVEL))
74 return obj_pool_free;
75
76 if (unlikely(!obj_cache))
77 return obj_pool_free;
78
79 while (obj_pool_free < ODEBUG_POOL_MIN_LEVEL) {
80
81 new = kmem_cache_zalloc(obj_cache, gfp);
82 if (!new)
83 return obj_pool_free;
84
Vegard Nossum50db04dd2008-06-15 00:47:36 +020085 spin_lock_irqsave(&pool_lock, flags);
Thomas Gleixner3ac7fe52008-04-30 00:55:01 -070086 hlist_add_head(&new->node, &obj_pool);
87 obj_pool_free++;
Vegard Nossum50db04dd2008-06-15 00:47:36 +020088 spin_unlock_irqrestore(&pool_lock, flags);
Thomas Gleixner3ac7fe52008-04-30 00:55:01 -070089 }
90 return obj_pool_free;
91}
92
93/*
94 * Lookup an object in the hash bucket.
95 */
96static struct debug_obj *lookup_object(void *addr, struct debug_bucket *b)
97{
98 struct hlist_node *node;
99 struct debug_obj *obj;
100 int cnt = 0;
101
102 hlist_for_each_entry(obj, node, &b->list, node) {
103 cnt++;
104 if (obj->object == addr)
105 return obj;
106 }
107 if (cnt > debug_objects_maxchain)
108 debug_objects_maxchain = cnt;
109
110 return NULL;
111}
112
113/*
Vegard Nossum50db04dd2008-06-15 00:47:36 +0200114 * Allocate a new object. If the pool is empty, switch off the debugger.
Vegard Nossum673d62cc2008-08-31 23:39:21 +0200115 * Must be called with interrupts disabled.
Thomas Gleixner3ac7fe52008-04-30 00:55:01 -0700116 */
117static struct debug_obj *
118alloc_object(void *addr, struct debug_bucket *b, struct debug_obj_descr *descr)
119{
120 struct debug_obj *obj = NULL;
Thomas Gleixner3ac7fe52008-04-30 00:55:01 -0700121
Thomas Gleixner3ac7fe52008-04-30 00:55:01 -0700122 spin_lock(&pool_lock);
123 if (obj_pool.first) {
124 obj = hlist_entry(obj_pool.first, typeof(*obj), node);
125
126 obj->object = addr;
127 obj->descr = descr;
128 obj->state = ODEBUG_STATE_NONE;
129 hlist_del(&obj->node);
130
131 hlist_add_head(&obj->node, &b->list);
132
133 obj_pool_used++;
134 if (obj_pool_used > obj_pool_max_used)
135 obj_pool_max_used = obj_pool_used;
136
137 obj_pool_free--;
138 if (obj_pool_free < obj_pool_min_free)
139 obj_pool_min_free = obj_pool_free;
140 }
141 spin_unlock(&pool_lock);
142
Thomas Gleixner3ac7fe52008-04-30 00:55:01 -0700143 return obj;
144}
145
146/*
147 * Put the object back into the pool or give it back to kmem_cache:
148 */
149static void free_object(struct debug_obj *obj)
150{
151 unsigned long idx = (unsigned long)(obj - obj_static_pool);
Vegard Nossum673d62cc2008-08-31 23:39:21 +0200152 unsigned long flags;
Thomas Gleixner3ac7fe52008-04-30 00:55:01 -0700153
154 if (obj_pool_free < ODEBUG_POOL_SIZE || idx < ODEBUG_POOL_SIZE) {
Vegard Nossum673d62cc2008-08-31 23:39:21 +0200155 spin_lock_irqsave(&pool_lock, flags);
Thomas Gleixner3ac7fe52008-04-30 00:55:01 -0700156 hlist_add_head(&obj->node, &obj_pool);
157 obj_pool_free++;
158 obj_pool_used--;
Vegard Nossum673d62cc2008-08-31 23:39:21 +0200159 spin_unlock_irqrestore(&pool_lock, flags);
Thomas Gleixner3ac7fe52008-04-30 00:55:01 -0700160 } else {
Vegard Nossum673d62cc2008-08-31 23:39:21 +0200161 spin_lock_irqsave(&pool_lock, flags);
Thomas Gleixner3ac7fe52008-04-30 00:55:01 -0700162 obj_pool_used--;
Vegard Nossum673d62cc2008-08-31 23:39:21 +0200163 spin_unlock_irqrestore(&pool_lock, flags);
Thomas Gleixner3ac7fe52008-04-30 00:55:01 -0700164 kmem_cache_free(obj_cache, obj);
165 }
166}
167
168/*
169 * We run out of memory. That means we probably have tons of objects
170 * allocated.
171 */
172static void debug_objects_oom(void)
173{
174 struct debug_bucket *db = obj_hash;
175 struct hlist_node *node, *tmp;
Vegard Nossum673d62cc2008-08-31 23:39:21 +0200176 HLIST_HEAD(freelist);
Thomas Gleixner3ac7fe52008-04-30 00:55:01 -0700177 struct debug_obj *obj;
178 unsigned long flags;
179 int i;
180
181 printk(KERN_WARNING "ODEBUG: Out of memory. ODEBUG disabled\n");
182
183 for (i = 0; i < ODEBUG_HASH_SIZE; i++, db++) {
184 spin_lock_irqsave(&db->lock, flags);
Vegard Nossum673d62cc2008-08-31 23:39:21 +0200185 hlist_move_list(&db->list, &freelist);
186 spin_unlock_irqrestore(&db->lock, flags);
187
188 /* Now free them */
189 hlist_for_each_entry_safe(obj, node, tmp, &freelist, node) {
Thomas Gleixner3ac7fe52008-04-30 00:55:01 -0700190 hlist_del(&obj->node);
191 free_object(obj);
192 }
Thomas Gleixner3ac7fe52008-04-30 00:55:01 -0700193 }
194}
195
196/*
197 * We use the pfn of the address for the hash. That way we can check
198 * for freed objects simply by checking the affected bucket.
199 */
200static struct debug_bucket *get_bucket(unsigned long addr)
201{
202 unsigned long hash;
203
204 hash = hash_long((addr >> ODEBUG_CHUNK_SHIFT), ODEBUG_HASH_BITS);
205 return &obj_hash[hash];
206}
207
208static void debug_print_object(struct debug_obj *obj, char *msg)
209{
210 static int limit;
211
212 if (limit < 5 && obj->descr != descr_test) {
213 limit++;
Arjan van de Ven5cd2b452008-07-25 19:45:39 -0700214 WARN(1, KERN_ERR "ODEBUG: %s %s object type: %s\n", msg,
Thomas Gleixner3ac7fe52008-04-30 00:55:01 -0700215 obj_states[obj->state], obj->descr->name);
Thomas Gleixner3ac7fe52008-04-30 00:55:01 -0700216 }
217 debug_objects_warnings++;
218}
219
220/*
221 * Try to repair the damage, so we have a better chance to get useful
222 * debug output.
223 */
224static void
225debug_object_fixup(int (*fixup)(void *addr, enum debug_obj_state state),
226 void * addr, enum debug_obj_state state)
227{
228 if (fixup)
229 debug_objects_fixups += fixup(addr, state);
230}
231
232static void debug_object_is_on_stack(void *addr, int onstack)
233{
Thomas Gleixner3ac7fe52008-04-30 00:55:01 -0700234 int is_on_stack;
235 static int limit;
236
237 if (limit > 4)
238 return;
239
FUJITA Tomonori8b05c7e2008-07-23 21:26:53 -0700240 is_on_stack = object_is_on_stack(addr);
Thomas Gleixner3ac7fe52008-04-30 00:55:01 -0700241 if (is_on_stack == onstack)
242 return;
243
244 limit++;
245 if (is_on_stack)
246 printk(KERN_WARNING
247 "ODEBUG: object is on stack, but not annotated\n");
248 else
249 printk(KERN_WARNING
250 "ODEBUG: object is not on stack, but annotated\n");
251 WARN_ON(1);
252}
253
254static void
255__debug_object_init(void *addr, struct debug_obj_descr *descr, int onstack)
256{
257 enum debug_obj_state state;
258 struct debug_bucket *db;
259 struct debug_obj *obj;
260 unsigned long flags;
261
Vegard Nossum50db04dd2008-06-15 00:47:36 +0200262 fill_pool();
263
Thomas Gleixner3ac7fe52008-04-30 00:55:01 -0700264 db = get_bucket((unsigned long) addr);
265
266 spin_lock_irqsave(&db->lock, flags);
267
268 obj = lookup_object(addr, db);
269 if (!obj) {
270 obj = alloc_object(addr, db, descr);
271 if (!obj) {
272 debug_objects_enabled = 0;
273 spin_unlock_irqrestore(&db->lock, flags);
274 debug_objects_oom();
275 return;
276 }
277 debug_object_is_on_stack(addr, onstack);
278 }
279
280 switch (obj->state) {
281 case ODEBUG_STATE_NONE:
282 case ODEBUG_STATE_INIT:
283 case ODEBUG_STATE_INACTIVE:
284 obj->state = ODEBUG_STATE_INIT;
285 break;
286
287 case ODEBUG_STATE_ACTIVE:
288 debug_print_object(obj, "init");
289 state = obj->state;
290 spin_unlock_irqrestore(&db->lock, flags);
291 debug_object_fixup(descr->fixup_init, addr, state);
292 return;
293
294 case ODEBUG_STATE_DESTROYED:
295 debug_print_object(obj, "init");
296 break;
297 default:
298 break;
299 }
300
301 spin_unlock_irqrestore(&db->lock, flags);
302}
303
304/**
305 * debug_object_init - debug checks when an object is initialized
306 * @addr: address of the object
307 * @descr: pointer to an object specific debug description structure
308 */
309void debug_object_init(void *addr, struct debug_obj_descr *descr)
310{
311 if (!debug_objects_enabled)
312 return;
313
314 __debug_object_init(addr, descr, 0);
315}
316
317/**
318 * debug_object_init_on_stack - debug checks when an object on stack is
319 * initialized
320 * @addr: address of the object
321 * @descr: pointer to an object specific debug description structure
322 */
323void debug_object_init_on_stack(void *addr, struct debug_obj_descr *descr)
324{
325 if (!debug_objects_enabled)
326 return;
327
328 __debug_object_init(addr, descr, 1);
329}
330
331/**
332 * debug_object_activate - debug checks when an object is activated
333 * @addr: address of the object
334 * @descr: pointer to an object specific debug description structure
335 */
336void debug_object_activate(void *addr, struct debug_obj_descr *descr)
337{
338 enum debug_obj_state state;
339 struct debug_bucket *db;
340 struct debug_obj *obj;
341 unsigned long flags;
342
343 if (!debug_objects_enabled)
344 return;
345
346 db = get_bucket((unsigned long) addr);
347
348 spin_lock_irqsave(&db->lock, flags);
349
350 obj = lookup_object(addr, db);
351 if (obj) {
352 switch (obj->state) {
353 case ODEBUG_STATE_INIT:
354 case ODEBUG_STATE_INACTIVE:
355 obj->state = ODEBUG_STATE_ACTIVE;
356 break;
357
358 case ODEBUG_STATE_ACTIVE:
359 debug_print_object(obj, "activate");
360 state = obj->state;
361 spin_unlock_irqrestore(&db->lock, flags);
362 debug_object_fixup(descr->fixup_activate, addr, state);
363 return;
364
365 case ODEBUG_STATE_DESTROYED:
366 debug_print_object(obj, "activate");
367 break;
368 default:
369 break;
370 }
371 spin_unlock_irqrestore(&db->lock, flags);
372 return;
373 }
374
375 spin_unlock_irqrestore(&db->lock, flags);
376 /*
377 * This happens when a static object is activated. We
378 * let the type specific code decide whether this is
379 * true or not.
380 */
381 debug_object_fixup(descr->fixup_activate, addr,
382 ODEBUG_STATE_NOTAVAILABLE);
383}
384
385/**
386 * debug_object_deactivate - debug checks when an object is deactivated
387 * @addr: address of the object
388 * @descr: pointer to an object specific debug description structure
389 */
390void debug_object_deactivate(void *addr, struct debug_obj_descr *descr)
391{
392 struct debug_bucket *db;
393 struct debug_obj *obj;
394 unsigned long flags;
395
396 if (!debug_objects_enabled)
397 return;
398
399 db = get_bucket((unsigned long) addr);
400
401 spin_lock_irqsave(&db->lock, flags);
402
403 obj = lookup_object(addr, db);
404 if (obj) {
405 switch (obj->state) {
406 case ODEBUG_STATE_INIT:
407 case ODEBUG_STATE_INACTIVE:
408 case ODEBUG_STATE_ACTIVE:
409 obj->state = ODEBUG_STATE_INACTIVE;
410 break;
411
412 case ODEBUG_STATE_DESTROYED:
413 debug_print_object(obj, "deactivate");
414 break;
415 default:
416 break;
417 }
418 } else {
419 struct debug_obj o = { .object = addr,
420 .state = ODEBUG_STATE_NOTAVAILABLE,
421 .descr = descr };
422
423 debug_print_object(&o, "deactivate");
424 }
425
426 spin_unlock_irqrestore(&db->lock, flags);
427}
428
429/**
430 * debug_object_destroy - debug checks when an object is destroyed
431 * @addr: address of the object
432 * @descr: pointer to an object specific debug description structure
433 */
434void debug_object_destroy(void *addr, struct debug_obj_descr *descr)
435{
436 enum debug_obj_state state;
437 struct debug_bucket *db;
438 struct debug_obj *obj;
439 unsigned long flags;
440
441 if (!debug_objects_enabled)
442 return;
443
444 db = get_bucket((unsigned long) addr);
445
446 spin_lock_irqsave(&db->lock, flags);
447
448 obj = lookup_object(addr, db);
449 if (!obj)
450 goto out_unlock;
451
452 switch (obj->state) {
453 case ODEBUG_STATE_NONE:
454 case ODEBUG_STATE_INIT:
455 case ODEBUG_STATE_INACTIVE:
456 obj->state = ODEBUG_STATE_DESTROYED;
457 break;
458 case ODEBUG_STATE_ACTIVE:
459 debug_print_object(obj, "destroy");
460 state = obj->state;
461 spin_unlock_irqrestore(&db->lock, flags);
462 debug_object_fixup(descr->fixup_destroy, addr, state);
463 return;
464
465 case ODEBUG_STATE_DESTROYED:
466 debug_print_object(obj, "destroy");
467 break;
468 default:
469 break;
470 }
471out_unlock:
472 spin_unlock_irqrestore(&db->lock, flags);
473}
474
475/**
476 * debug_object_free - debug checks when an object is freed
477 * @addr: address of the object
478 * @descr: pointer to an object specific debug description structure
479 */
480void debug_object_free(void *addr, struct debug_obj_descr *descr)
481{
482 enum debug_obj_state state;
483 struct debug_bucket *db;
484 struct debug_obj *obj;
485 unsigned long flags;
486
487 if (!debug_objects_enabled)
488 return;
489
490 db = get_bucket((unsigned long) addr);
491
492 spin_lock_irqsave(&db->lock, flags);
493
494 obj = lookup_object(addr, db);
495 if (!obj)
496 goto out_unlock;
497
498 switch (obj->state) {
499 case ODEBUG_STATE_ACTIVE:
500 debug_print_object(obj, "free");
501 state = obj->state;
502 spin_unlock_irqrestore(&db->lock, flags);
503 debug_object_fixup(descr->fixup_free, addr, state);
504 return;
505 default:
506 hlist_del(&obj->node);
Vegard Nossum673d62cc2008-08-31 23:39:21 +0200507 spin_unlock_irqrestore(&db->lock, flags);
Thomas Gleixner3ac7fe52008-04-30 00:55:01 -0700508 free_object(obj);
Vegard Nossum673d62cc2008-08-31 23:39:21 +0200509 return;
Thomas Gleixner3ac7fe52008-04-30 00:55:01 -0700510 }
511out_unlock:
512 spin_unlock_irqrestore(&db->lock, flags);
513}
514
515#ifdef CONFIG_DEBUG_OBJECTS_FREE
516static void __debug_check_no_obj_freed(const void *address, unsigned long size)
517{
518 unsigned long flags, oaddr, saddr, eaddr, paddr, chunks;
519 struct hlist_node *node, *tmp;
Vegard Nossum673d62cc2008-08-31 23:39:21 +0200520 HLIST_HEAD(freelist);
Thomas Gleixner3ac7fe52008-04-30 00:55:01 -0700521 struct debug_obj_descr *descr;
522 enum debug_obj_state state;
523 struct debug_bucket *db;
524 struct debug_obj *obj;
525 int cnt;
526
527 saddr = (unsigned long) address;
528 eaddr = saddr + size;
529 paddr = saddr & ODEBUG_CHUNK_MASK;
530 chunks = ((eaddr - paddr) + (ODEBUG_CHUNK_SIZE - 1));
531 chunks >>= ODEBUG_CHUNK_SHIFT;
532
533 for (;chunks > 0; chunks--, paddr += ODEBUG_CHUNK_SIZE) {
534 db = get_bucket(paddr);
535
536repeat:
537 cnt = 0;
538 spin_lock_irqsave(&db->lock, flags);
539 hlist_for_each_entry_safe(obj, node, tmp, &db->list, node) {
540 cnt++;
541 oaddr = (unsigned long) obj->object;
542 if (oaddr < saddr || oaddr >= eaddr)
543 continue;
544
545 switch (obj->state) {
546 case ODEBUG_STATE_ACTIVE:
547 debug_print_object(obj, "free");
548 descr = obj->descr;
549 state = obj->state;
550 spin_unlock_irqrestore(&db->lock, flags);
551 debug_object_fixup(descr->fixup_free,
552 (void *) oaddr, state);
553 goto repeat;
554 default:
555 hlist_del(&obj->node);
Vegard Nossum673d62cc2008-08-31 23:39:21 +0200556 hlist_add_head(&obj->node, &freelist);
Thomas Gleixner3ac7fe52008-04-30 00:55:01 -0700557 break;
558 }
559 }
560 spin_unlock_irqrestore(&db->lock, flags);
Vegard Nossum673d62cc2008-08-31 23:39:21 +0200561
562 /* Now free them */
563 hlist_for_each_entry_safe(obj, node, tmp, &freelist, node) {
564 hlist_del(&obj->node);
565 free_object(obj);
566 }
567
Thomas Gleixner3ac7fe52008-04-30 00:55:01 -0700568 if (cnt > debug_objects_maxchain)
569 debug_objects_maxchain = cnt;
570 }
571}
572
573void debug_check_no_obj_freed(const void *address, unsigned long size)
574{
575 if (debug_objects_enabled)
576 __debug_check_no_obj_freed(address, size);
577}
578#endif
579
580#ifdef CONFIG_DEBUG_FS
581
582static int debug_stats_show(struct seq_file *m, void *v)
583{
584 seq_printf(m, "max_chain :%d\n", debug_objects_maxchain);
585 seq_printf(m, "warnings :%d\n", debug_objects_warnings);
586 seq_printf(m, "fixups :%d\n", debug_objects_fixups);
587 seq_printf(m, "pool_free :%d\n", obj_pool_free);
588 seq_printf(m, "pool_min_free :%d\n", obj_pool_min_free);
589 seq_printf(m, "pool_used :%d\n", obj_pool_used);
590 seq_printf(m, "pool_max_used :%d\n", obj_pool_max_used);
591 return 0;
592}
593
594static int debug_stats_open(struct inode *inode, struct file *filp)
595{
596 return single_open(filp, debug_stats_show, NULL);
597}
598
599static const struct file_operations debug_stats_fops = {
600 .open = debug_stats_open,
601 .read = seq_read,
602 .llseek = seq_lseek,
603 .release = single_release,
604};
605
606static int __init debug_objects_init_debugfs(void)
607{
608 struct dentry *dbgdir, *dbgstats;
609
610 if (!debug_objects_enabled)
611 return 0;
612
613 dbgdir = debugfs_create_dir("debug_objects", NULL);
614 if (!dbgdir)
615 return -ENOMEM;
616
617 dbgstats = debugfs_create_file("stats", 0444, dbgdir, NULL,
618 &debug_stats_fops);
619 if (!dbgstats)
620 goto err;
621
622 return 0;
623
624err:
625 debugfs_remove(dbgdir);
626
627 return -ENOMEM;
628}
629__initcall(debug_objects_init_debugfs);
630
631#else
632static inline void debug_objects_init_debugfs(void) { }
633#endif
634
635#ifdef CONFIG_DEBUG_OBJECTS_SELFTEST
636
637/* Random data structure for the self test */
638struct self_test {
639 unsigned long dummy1[6];
640 int static_init;
641 unsigned long dummy2[3];
642};
643
644static __initdata struct debug_obj_descr descr_type_test;
645
646/*
647 * fixup_init is called when:
648 * - an active object is initialized
649 */
650static int __init fixup_init(void *addr, enum debug_obj_state state)
651{
652 struct self_test *obj = addr;
653
654 switch (state) {
655 case ODEBUG_STATE_ACTIVE:
656 debug_object_deactivate(obj, &descr_type_test);
657 debug_object_init(obj, &descr_type_test);
658 return 1;
659 default:
660 return 0;
661 }
662}
663
664/*
665 * fixup_activate is called when:
666 * - an active object is activated
667 * - an unknown object is activated (might be a statically initialized object)
668 */
669static int __init fixup_activate(void *addr, enum debug_obj_state state)
670{
671 struct self_test *obj = addr;
672
673 switch (state) {
674 case ODEBUG_STATE_NOTAVAILABLE:
675 if (obj->static_init == 1) {
676 debug_object_init(obj, &descr_type_test);
677 debug_object_activate(obj, &descr_type_test);
678 /*
679 * Real code should return 0 here ! This is
680 * not a fixup of some bad behaviour. We
681 * merily call the debug_init function to keep
682 * track of the object.
683 */
684 return 1;
685 } else {
686 /* Real code needs to emit a warning here */
687 }
688 return 0;
689
690 case ODEBUG_STATE_ACTIVE:
691 debug_object_deactivate(obj, &descr_type_test);
692 debug_object_activate(obj, &descr_type_test);
693 return 1;
694
695 default:
696 return 0;
697 }
698}
699
700/*
701 * fixup_destroy is called when:
702 * - an active object is destroyed
703 */
704static int __init fixup_destroy(void *addr, enum debug_obj_state state)
705{
706 struct self_test *obj = addr;
707
708 switch (state) {
709 case ODEBUG_STATE_ACTIVE:
710 debug_object_deactivate(obj, &descr_type_test);
711 debug_object_destroy(obj, &descr_type_test);
712 return 1;
713 default:
714 return 0;
715 }
716}
717
718/*
719 * fixup_free is called when:
720 * - an active object is freed
721 */
722static int __init fixup_free(void *addr, enum debug_obj_state state)
723{
724 struct self_test *obj = addr;
725
726 switch (state) {
727 case ODEBUG_STATE_ACTIVE:
728 debug_object_deactivate(obj, &descr_type_test);
729 debug_object_free(obj, &descr_type_test);
730 return 1;
731 default:
732 return 0;
733 }
734}
735
736static int
737check_results(void *addr, enum debug_obj_state state, int fixups, int warnings)
738{
739 struct debug_bucket *db;
740 struct debug_obj *obj;
741 unsigned long flags;
742 int res = -EINVAL;
743
744 db = get_bucket((unsigned long) addr);
745
746 spin_lock_irqsave(&db->lock, flags);
747
748 obj = lookup_object(addr, db);
749 if (!obj && state != ODEBUG_STATE_NONE) {
Arjan van de Ven5cd2b452008-07-25 19:45:39 -0700750 WARN(1, KERN_ERR "ODEBUG: selftest object not found\n");
Thomas Gleixner3ac7fe52008-04-30 00:55:01 -0700751 goto out;
752 }
753 if (obj && obj->state != state) {
Arjan van de Ven5cd2b452008-07-25 19:45:39 -0700754 WARN(1, KERN_ERR "ODEBUG: selftest wrong state: %d != %d\n",
Thomas Gleixner3ac7fe52008-04-30 00:55:01 -0700755 obj->state, state);
Thomas Gleixner3ac7fe52008-04-30 00:55:01 -0700756 goto out;
757 }
758 if (fixups != debug_objects_fixups) {
Arjan van de Ven5cd2b452008-07-25 19:45:39 -0700759 WARN(1, KERN_ERR "ODEBUG: selftest fixups failed %d != %d\n",
Thomas Gleixner3ac7fe52008-04-30 00:55:01 -0700760 fixups, debug_objects_fixups);
Thomas Gleixner3ac7fe52008-04-30 00:55:01 -0700761 goto out;
762 }
763 if (warnings != debug_objects_warnings) {
Arjan van de Ven5cd2b452008-07-25 19:45:39 -0700764 WARN(1, KERN_ERR "ODEBUG: selftest warnings failed %d != %d\n",
Thomas Gleixner3ac7fe52008-04-30 00:55:01 -0700765 warnings, debug_objects_warnings);
Thomas Gleixner3ac7fe52008-04-30 00:55:01 -0700766 goto out;
767 }
768 res = 0;
769out:
770 spin_unlock_irqrestore(&db->lock, flags);
771 if (res)
772 debug_objects_enabled = 0;
773 return res;
774}
775
776static __initdata struct debug_obj_descr descr_type_test = {
777 .name = "selftest",
778 .fixup_init = fixup_init,
779 .fixup_activate = fixup_activate,
780 .fixup_destroy = fixup_destroy,
781 .fixup_free = fixup_free,
782};
783
784static __initdata struct self_test obj = { .static_init = 0 };
785
786static void __init debug_objects_selftest(void)
787{
788 int fixups, oldfixups, warnings, oldwarnings;
789 unsigned long flags;
790
791 local_irq_save(flags);
792
793 fixups = oldfixups = debug_objects_fixups;
794 warnings = oldwarnings = debug_objects_warnings;
795 descr_test = &descr_type_test;
796
797 debug_object_init(&obj, &descr_type_test);
798 if (check_results(&obj, ODEBUG_STATE_INIT, fixups, warnings))
799 goto out;
800 debug_object_activate(&obj, &descr_type_test);
801 if (check_results(&obj, ODEBUG_STATE_ACTIVE, fixups, warnings))
802 goto out;
803 debug_object_activate(&obj, &descr_type_test);
804 if (check_results(&obj, ODEBUG_STATE_ACTIVE, ++fixups, ++warnings))
805 goto out;
806 debug_object_deactivate(&obj, &descr_type_test);
807 if (check_results(&obj, ODEBUG_STATE_INACTIVE, fixups, warnings))
808 goto out;
809 debug_object_destroy(&obj, &descr_type_test);
810 if (check_results(&obj, ODEBUG_STATE_DESTROYED, fixups, warnings))
811 goto out;
812 debug_object_init(&obj, &descr_type_test);
813 if (check_results(&obj, ODEBUG_STATE_DESTROYED, fixups, ++warnings))
814 goto out;
815 debug_object_activate(&obj, &descr_type_test);
816 if (check_results(&obj, ODEBUG_STATE_DESTROYED, fixups, ++warnings))
817 goto out;
818 debug_object_deactivate(&obj, &descr_type_test);
819 if (check_results(&obj, ODEBUG_STATE_DESTROYED, fixups, ++warnings))
820 goto out;
821 debug_object_free(&obj, &descr_type_test);
822 if (check_results(&obj, ODEBUG_STATE_NONE, fixups, warnings))
823 goto out;
824
825 obj.static_init = 1;
826 debug_object_activate(&obj, &descr_type_test);
827 if (check_results(&obj, ODEBUG_STATE_ACTIVE, ++fixups, warnings))
828 goto out;
829 debug_object_init(&obj, &descr_type_test);
830 if (check_results(&obj, ODEBUG_STATE_INIT, ++fixups, ++warnings))
831 goto out;
832 debug_object_free(&obj, &descr_type_test);
833 if (check_results(&obj, ODEBUG_STATE_NONE, fixups, warnings))
834 goto out;
835
836#ifdef CONFIG_DEBUG_OBJECTS_FREE
837 debug_object_init(&obj, &descr_type_test);
838 if (check_results(&obj, ODEBUG_STATE_INIT, fixups, warnings))
839 goto out;
840 debug_object_activate(&obj, &descr_type_test);
841 if (check_results(&obj, ODEBUG_STATE_ACTIVE, fixups, warnings))
842 goto out;
843 __debug_check_no_obj_freed(&obj, sizeof(obj));
844 if (check_results(&obj, ODEBUG_STATE_NONE, ++fixups, ++warnings))
845 goto out;
846#endif
847 printk(KERN_INFO "ODEBUG: selftest passed\n");
848
849out:
850 debug_objects_fixups = oldfixups;
851 debug_objects_warnings = oldwarnings;
852 descr_test = NULL;
853
854 local_irq_restore(flags);
855}
856#else
857static inline void debug_objects_selftest(void) { }
858#endif
859
860/*
861 * Called during early boot to initialize the hash buckets and link
862 * the static object pool objects into the poll list. After this call
863 * the object tracker is fully operational.
864 */
865void __init debug_objects_early_init(void)
866{
867 int i;
868
869 for (i = 0; i < ODEBUG_HASH_SIZE; i++)
870 spin_lock_init(&obj_hash[i].lock);
871
872 for (i = 0; i < ODEBUG_POOL_SIZE; i++)
873 hlist_add_head(&obj_static_pool[i].node, &obj_pool);
874}
875
876/*
877 * Called after the kmem_caches are functional to setup a dedicated
878 * cache pool, which has the SLAB_DEBUG_OBJECTS flag set. This flag
879 * prevents that the debug code is called on kmem_cache_free() for the
880 * debug tracker objects to avoid recursive calls.
881 */
882void __init debug_objects_mem_init(void)
883{
884 if (!debug_objects_enabled)
885 return;
886
887 obj_cache = kmem_cache_create("debug_objects_cache",
888 sizeof (struct debug_obj), 0,
889 SLAB_DEBUG_OBJECTS, NULL);
890
891 if (!obj_cache)
892 debug_objects_enabled = 0;
893 else
894 debug_objects_selftest();
895}