| 1 | // SPDX-License-Identifier: GPL-2.0 |
| 2 | /* |
| 3 | * Generic infrastructure for lifetime debugging of objects. |
| 4 | * |
| 5 | * Copyright (C) 2008, Thomas Gleixner <tglx@linutronix.de> |
| 6 | */ |
| 7 | |
| 8 | #define pr_fmt(fmt) "ODEBUG: " fmt |
| 9 | |
| 10 | #include <linux/debugobjects.h> |
| 11 | #include <linux/interrupt.h> |
| 12 | #include <linux/sched.h> |
| 13 | #include <linux/sched/task_stack.h> |
| 14 | #include <linux/seq_file.h> |
| 15 | #include <linux/debugfs.h> |
| 16 | #include <linux/slab.h> |
| 17 | #include <linux/hash.h> |
| 18 | #include <linux/kmemleak.h> |
| 19 | #include <linux/cpu.h> |
| 20 | |
| 21 | #define ODEBUG_HASH_BITS 14 |
| 22 | #define ODEBUG_HASH_SIZE (1 << ODEBUG_HASH_BITS) |
| 23 | |
| 24 | #define ODEBUG_POOL_SIZE 1024 |
| 25 | #define ODEBUG_POOL_MIN_LEVEL 256 |
| 26 | #define ODEBUG_POOL_PERCPU_SIZE 64 |
| 27 | #define ODEBUG_BATCH_SIZE 16 |
| 28 | |
| 29 | #define ODEBUG_CHUNK_SHIFT PAGE_SHIFT |
| 30 | #define ODEBUG_CHUNK_SIZE (1 << ODEBUG_CHUNK_SHIFT) |
| 31 | #define ODEBUG_CHUNK_MASK (~(ODEBUG_CHUNK_SIZE - 1)) |
| 32 | |
| 33 | /* |
| 34 | * We limit the freeing of debug objects via workqueue at a maximum |
| 35 | * frequency of 10Hz and about 1024 objects for each freeing operation. |
| 36 | * So it is freeing at most 10k debug objects per second. |
| 37 | */ |
| 38 | #define ODEBUG_FREE_WORK_MAX 1024 |
| 39 | #define ODEBUG_FREE_WORK_DELAY DIV_ROUND_UP(HZ, 10) |
| 40 | |
| 41 | struct debug_bucket { |
| 42 | struct hlist_head list; |
| 43 | raw_spinlock_t lock; |
| 44 | }; |
| 45 | |
| 46 | /* |
| 47 | * Debug object percpu free list |
| 48 | * Access is protected by disabling irq |
| 49 | */ |
| 50 | struct debug_percpu_free { |
| 51 | struct hlist_head free_objs; |
| 52 | int obj_free; |
| 53 | }; |
| 54 | |
| 55 | static DEFINE_PER_CPU(struct debug_percpu_free, percpu_obj_pool); |
| 56 | |
| 57 | static struct debug_bucket obj_hash[ODEBUG_HASH_SIZE]; |
| 58 | |
| 59 | static struct debug_obj obj_static_pool[ODEBUG_POOL_SIZE] __initdata; |
| 60 | |
| 61 | static DEFINE_RAW_SPINLOCK(pool_lock); |
| 62 | |
| 63 | static HLIST_HEAD(obj_pool); |
| 64 | static HLIST_HEAD(obj_to_free); |
| 65 | |
| 66 | /* |
| 67 | * Because of the presence of percpu free pools, obj_pool_free will |
| 68 | * under-count those in the percpu free pools. Similarly, obj_pool_used |
| 69 | * will over-count those in the percpu free pools. Adjustments will be |
| 70 | * made at debug_stats_show(). Both obj_pool_min_free and obj_pool_max_used |
| 71 | * can be off. |
| 72 | */ |
| 73 | static int obj_pool_min_free = ODEBUG_POOL_SIZE; |
| 74 | static int obj_pool_free = ODEBUG_POOL_SIZE; |
| 75 | static int obj_pool_used; |
| 76 | static int obj_pool_max_used; |
| 77 | static bool obj_freeing; |
| 78 | /* The number of objs on the global free list */ |
| 79 | static int obj_nr_tofree; |
| 80 | |
| 81 | static int debug_objects_maxchain __read_mostly; |
| 82 | static int __maybe_unused debug_objects_maxchecked __read_mostly; |
| 83 | static int debug_objects_fixups __read_mostly; |
| 84 | static int debug_objects_warnings __read_mostly; |
| 85 | static int debug_objects_enabled __read_mostly |
| 86 | = CONFIG_DEBUG_OBJECTS_ENABLE_DEFAULT; |
| 87 | static int debug_objects_pool_size __read_mostly |
| 88 | = ODEBUG_POOL_SIZE; |
| 89 | static int debug_objects_pool_min_level __read_mostly |
| 90 | = ODEBUG_POOL_MIN_LEVEL; |
| 91 | static const struct debug_obj_descr *descr_test __read_mostly; |
| 92 | static struct kmem_cache *obj_cache __read_mostly; |
| 93 | |
| 94 | /* |
| 95 | * Track numbers of kmem_cache_alloc()/free() calls done. |
| 96 | */ |
| 97 | static int debug_objects_allocated; |
| 98 | static int debug_objects_freed; |
| 99 | |
| 100 | static void free_obj_work(struct work_struct *work); |
| 101 | static DECLARE_DELAYED_WORK(debug_obj_work, free_obj_work); |
| 102 | |
| 103 | static int __init enable_object_debug(char *str) |
| 104 | { |
| 105 | debug_objects_enabled = 1; |
| 106 | return 0; |
| 107 | } |
| 108 | |
| 109 | static int __init disable_object_debug(char *str) |
| 110 | { |
| 111 | debug_objects_enabled = 0; |
| 112 | return 0; |
| 113 | } |
| 114 | |
| 115 | early_param("debug_objects", enable_object_debug); |
| 116 | early_param("no_debug_objects", disable_object_debug); |
| 117 | |
| 118 | static const char *obj_states[ODEBUG_STATE_MAX] = { |
| 119 | [ODEBUG_STATE_NONE] = "none", |
| 120 | [ODEBUG_STATE_INIT] = "initialized", |
| 121 | [ODEBUG_STATE_INACTIVE] = "inactive", |
| 122 | [ODEBUG_STATE_ACTIVE] = "active", |
| 123 | [ODEBUG_STATE_DESTROYED] = "destroyed", |
| 124 | [ODEBUG_STATE_NOTAVAILABLE] = "not available", |
| 125 | }; |
| 126 | |
| 127 | static void fill_pool(void) |
| 128 | { |
| 129 | gfp_t gfp = GFP_ATOMIC | __GFP_NORETRY | __GFP_NOWARN; |
| 130 | struct debug_obj *obj; |
| 131 | unsigned long flags; |
| 132 | |
| 133 | if (likely(READ_ONCE(obj_pool_free) >= debug_objects_pool_min_level)) |
| 134 | return; |
| 135 | |
| 136 | /* |
| 137 | * Reuse objs from the global free list; they will be reinitialized |
| 138 | * when allocating. |
| 139 | * |
| 140 | * Both obj_nr_tofree and obj_pool_free are checked locklessly; the |
| 141 | * READ_ONCE()s pair with the WRITE_ONCE()s in pool_lock critical |
| 142 | * sections. |
| 143 | */ |
| 144 | while (READ_ONCE(obj_nr_tofree) && (READ_ONCE(obj_pool_free) < obj_pool_min_free)) { |
| 145 | raw_spin_lock_irqsave(&pool_lock, flags); |
| 146 | /* |
| 147 | * Recheck with the lock held as the worker thread might have |
| 148 | * won the race and freed the global free list already. |
| 149 | */ |
| 150 | while (obj_nr_tofree && (obj_pool_free < obj_pool_min_free)) { |
| 151 | obj = hlist_entry(obj_to_free.first, typeof(*obj), node); |
| 152 | hlist_del(&obj->node); |
| 153 | WRITE_ONCE(obj_nr_tofree, obj_nr_tofree - 1); |
| 154 | hlist_add_head(&obj->node, &obj_pool); |
| 155 | WRITE_ONCE(obj_pool_free, obj_pool_free + 1); |
| 156 | } |
| 157 | raw_spin_unlock_irqrestore(&pool_lock, flags); |
| 158 | } |
| 159 | |
| 160 | if (unlikely(!obj_cache)) |
| 161 | return; |
| 162 | |
| 163 | while (READ_ONCE(obj_pool_free) < debug_objects_pool_min_level) { |
| 164 | struct debug_obj *new[ODEBUG_BATCH_SIZE]; |
| 165 | int cnt; |
| 166 | |
| 167 | for (cnt = 0; cnt < ODEBUG_BATCH_SIZE; cnt++) { |
| 168 | new[cnt] = kmem_cache_zalloc(obj_cache, gfp); |
| 169 | if (!new[cnt]) |
| 170 | break; |
| 171 | } |
| 172 | if (!cnt) |
| 173 | return; |
| 174 | |
| 175 | raw_spin_lock_irqsave(&pool_lock, flags); |
| 176 | while (cnt) { |
| 177 | hlist_add_head(&new[--cnt]->node, &obj_pool); |
| 178 | debug_objects_allocated++; |
| 179 | WRITE_ONCE(obj_pool_free, obj_pool_free + 1); |
| 180 | } |
| 181 | raw_spin_unlock_irqrestore(&pool_lock, flags); |
| 182 | } |
| 183 | } |
| 184 | |
| 185 | /* |
| 186 | * Lookup an object in the hash bucket. |
| 187 | */ |
| 188 | static struct debug_obj *lookup_object(void *addr, struct debug_bucket *b) |
| 189 | { |
| 190 | struct debug_obj *obj; |
| 191 | int cnt = 0; |
| 192 | |
| 193 | hlist_for_each_entry(obj, &b->list, node) { |
| 194 | cnt++; |
| 195 | if (obj->object == addr) |
| 196 | return obj; |
| 197 | } |
| 198 | if (cnt > debug_objects_maxchain) |
| 199 | debug_objects_maxchain = cnt; |
| 200 | |
| 201 | return NULL; |
| 202 | } |
| 203 | |
| 204 | /* |
| 205 | * Allocate a new object from the hlist |
| 206 | */ |
| 207 | static struct debug_obj *__alloc_object(struct hlist_head *list) |
| 208 | { |
| 209 | struct debug_obj *obj = NULL; |
| 210 | |
| 211 | if (list->first) { |
| 212 | obj = hlist_entry(list->first, typeof(*obj), node); |
| 213 | hlist_del(&obj->node); |
| 214 | } |
| 215 | |
| 216 | return obj; |
| 217 | } |
| 218 | |
| 219 | static struct debug_obj * |
| 220 | alloc_object(void *addr, struct debug_bucket *b, const struct debug_obj_descr *descr) |
| 221 | { |
| 222 | struct debug_percpu_free *percpu_pool = this_cpu_ptr(&percpu_obj_pool); |
| 223 | struct debug_obj *obj; |
| 224 | |
| 225 | if (likely(obj_cache)) { |
| 226 | obj = __alloc_object(&percpu_pool->free_objs); |
| 227 | if (obj) { |
| 228 | percpu_pool->obj_free--; |
| 229 | goto init_obj; |
| 230 | } |
| 231 | } |
| 232 | |
| 233 | raw_spin_lock(&pool_lock); |
| 234 | obj = __alloc_object(&obj_pool); |
| 235 | if (obj) { |
| 236 | obj_pool_used++; |
| 237 | WRITE_ONCE(obj_pool_free, obj_pool_free - 1); |
| 238 | |
| 239 | /* |
| 240 | * Looking ahead, allocate one batch of debug objects and |
| 241 | * put them into the percpu free pool. |
| 242 | */ |
| 243 | if (likely(obj_cache)) { |
| 244 | int i; |
| 245 | |
| 246 | for (i = 0; i < ODEBUG_BATCH_SIZE; i++) { |
| 247 | struct debug_obj *obj2; |
| 248 | |
| 249 | obj2 = __alloc_object(&obj_pool); |
| 250 | if (!obj2) |
| 251 | break; |
| 252 | hlist_add_head(&obj2->node, |
| 253 | &percpu_pool->free_objs); |
| 254 | percpu_pool->obj_free++; |
| 255 | obj_pool_used++; |
| 256 | WRITE_ONCE(obj_pool_free, obj_pool_free - 1); |
| 257 | } |
| 258 | } |
| 259 | |
| 260 | if (obj_pool_used > obj_pool_max_used) |
| 261 | obj_pool_max_used = obj_pool_used; |
| 262 | |
| 263 | if (obj_pool_free < obj_pool_min_free) |
| 264 | obj_pool_min_free = obj_pool_free; |
| 265 | } |
| 266 | raw_spin_unlock(&pool_lock); |
| 267 | |
| 268 | init_obj: |
| 269 | if (obj) { |
| 270 | obj->object = addr; |
| 271 | obj->descr = descr; |
| 272 | obj->state = ODEBUG_STATE_NONE; |
| 273 | obj->astate = 0; |
| 274 | hlist_add_head(&obj->node, &b->list); |
| 275 | } |
| 276 | return obj; |
| 277 | } |
| 278 | |
| 279 | /* |
| 280 | * workqueue function to free objects. |
| 281 | * |
| 282 | * To reduce contention on the global pool_lock, the actual freeing of |
| 283 | * debug objects will be delayed if the pool_lock is busy. |
| 284 | */ |
| 285 | static void free_obj_work(struct work_struct *work) |
| 286 | { |
| 287 | struct hlist_node *tmp; |
| 288 | struct debug_obj *obj; |
| 289 | unsigned long flags; |
| 290 | HLIST_HEAD(tofree); |
| 291 | |
| 292 | WRITE_ONCE(obj_freeing, false); |
| 293 | if (!raw_spin_trylock_irqsave(&pool_lock, flags)) |
| 294 | return; |
| 295 | |
| 296 | if (obj_pool_free >= debug_objects_pool_size) |
| 297 | goto free_objs; |
| 298 | |
| 299 | /* |
| 300 | * The objs on the pool list might be allocated before the work is |
| 301 | * run, so recheck if pool list it full or not, if not fill pool |
| 302 | * list from the global free list. As it is likely that a workload |
| 303 | * may be gearing up to use more and more objects, don't free any |
| 304 | * of them until the next round. |
| 305 | */ |
| 306 | while (obj_nr_tofree && obj_pool_free < debug_objects_pool_size) { |
| 307 | obj = hlist_entry(obj_to_free.first, typeof(*obj), node); |
| 308 | hlist_del(&obj->node); |
| 309 | hlist_add_head(&obj->node, &obj_pool); |
| 310 | WRITE_ONCE(obj_pool_free, obj_pool_free + 1); |
| 311 | WRITE_ONCE(obj_nr_tofree, obj_nr_tofree - 1); |
| 312 | } |
| 313 | raw_spin_unlock_irqrestore(&pool_lock, flags); |
| 314 | return; |
| 315 | |
| 316 | free_objs: |
| 317 | /* |
| 318 | * Pool list is already full and there are still objs on the free |
| 319 | * list. Move remaining free objs to a temporary list to free the |
| 320 | * memory outside the pool_lock held region. |
| 321 | */ |
| 322 | if (obj_nr_tofree) { |
| 323 | hlist_move_list(&obj_to_free, &tofree); |
| 324 | debug_objects_freed += obj_nr_tofree; |
| 325 | WRITE_ONCE(obj_nr_tofree, 0); |
| 326 | } |
| 327 | raw_spin_unlock_irqrestore(&pool_lock, flags); |
| 328 | |
| 329 | hlist_for_each_entry_safe(obj, tmp, &tofree, node) { |
| 330 | hlist_del(&obj->node); |
| 331 | kmem_cache_free(obj_cache, obj); |
| 332 | } |
| 333 | } |
| 334 | |
| 335 | static void __free_object(struct debug_obj *obj) |
| 336 | { |
| 337 | struct debug_obj *objs[ODEBUG_BATCH_SIZE]; |
| 338 | struct debug_percpu_free *percpu_pool; |
| 339 | int lookahead_count = 0; |
| 340 | unsigned long flags; |
| 341 | bool work; |
| 342 | |
| 343 | local_irq_save(flags); |
| 344 | if (!obj_cache) |
| 345 | goto free_to_obj_pool; |
| 346 | |
| 347 | /* |
| 348 | * Try to free it into the percpu pool first. |
| 349 | */ |
| 350 | percpu_pool = this_cpu_ptr(&percpu_obj_pool); |
| 351 | if (percpu_pool->obj_free < ODEBUG_POOL_PERCPU_SIZE) { |
| 352 | hlist_add_head(&obj->node, &percpu_pool->free_objs); |
| 353 | percpu_pool->obj_free++; |
| 354 | local_irq_restore(flags); |
| 355 | return; |
| 356 | } |
| 357 | |
| 358 | /* |
| 359 | * As the percpu pool is full, look ahead and pull out a batch |
| 360 | * of objects from the percpu pool and free them as well. |
| 361 | */ |
| 362 | for (; lookahead_count < ODEBUG_BATCH_SIZE; lookahead_count++) { |
| 363 | objs[lookahead_count] = __alloc_object(&percpu_pool->free_objs); |
| 364 | if (!objs[lookahead_count]) |
| 365 | break; |
| 366 | percpu_pool->obj_free--; |
| 367 | } |
| 368 | |
| 369 | free_to_obj_pool: |
| 370 | raw_spin_lock(&pool_lock); |
| 371 | work = (obj_pool_free > debug_objects_pool_size) && obj_cache && |
| 372 | (obj_nr_tofree < ODEBUG_FREE_WORK_MAX); |
| 373 | obj_pool_used--; |
| 374 | |
| 375 | if (work) { |
| 376 | WRITE_ONCE(obj_nr_tofree, obj_nr_tofree + 1); |
| 377 | hlist_add_head(&obj->node, &obj_to_free); |
| 378 | if (lookahead_count) { |
| 379 | WRITE_ONCE(obj_nr_tofree, obj_nr_tofree + lookahead_count); |
| 380 | obj_pool_used -= lookahead_count; |
| 381 | while (lookahead_count) { |
| 382 | hlist_add_head(&objs[--lookahead_count]->node, |
| 383 | &obj_to_free); |
| 384 | } |
| 385 | } |
| 386 | |
| 387 | if ((obj_pool_free > debug_objects_pool_size) && |
| 388 | (obj_nr_tofree < ODEBUG_FREE_WORK_MAX)) { |
| 389 | int i; |
| 390 | |
| 391 | /* |
| 392 | * Free one more batch of objects from obj_pool. |
| 393 | */ |
| 394 | for (i = 0; i < ODEBUG_BATCH_SIZE; i++) { |
| 395 | obj = __alloc_object(&obj_pool); |
| 396 | hlist_add_head(&obj->node, &obj_to_free); |
| 397 | WRITE_ONCE(obj_pool_free, obj_pool_free - 1); |
| 398 | WRITE_ONCE(obj_nr_tofree, obj_nr_tofree + 1); |
| 399 | } |
| 400 | } |
| 401 | } else { |
| 402 | WRITE_ONCE(obj_pool_free, obj_pool_free + 1); |
| 403 | hlist_add_head(&obj->node, &obj_pool); |
| 404 | if (lookahead_count) { |
| 405 | WRITE_ONCE(obj_pool_free, obj_pool_free + lookahead_count); |
| 406 | obj_pool_used -= lookahead_count; |
| 407 | while (lookahead_count) { |
| 408 | hlist_add_head(&objs[--lookahead_count]->node, |
| 409 | &obj_pool); |
| 410 | } |
| 411 | } |
| 412 | } |
| 413 | raw_spin_unlock(&pool_lock); |
| 414 | local_irq_restore(flags); |
| 415 | } |
| 416 | |
| 417 | /* |
| 418 | * Put the object back into the pool and schedule work to free objects |
| 419 | * if necessary. |
| 420 | */ |
| 421 | static void free_object(struct debug_obj *obj) |
| 422 | { |
| 423 | __free_object(obj); |
| 424 | if (!READ_ONCE(obj_freeing) && READ_ONCE(obj_nr_tofree)) { |
| 425 | WRITE_ONCE(obj_freeing, true); |
| 426 | schedule_delayed_work(&debug_obj_work, ODEBUG_FREE_WORK_DELAY); |
| 427 | } |
| 428 | } |
| 429 | |
| 430 | #ifdef CONFIG_HOTPLUG_CPU |
| 431 | static int object_cpu_offline(unsigned int cpu) |
| 432 | { |
| 433 | struct debug_percpu_free *percpu_pool; |
| 434 | struct hlist_node *tmp; |
| 435 | struct debug_obj *obj; |
| 436 | unsigned long flags; |
| 437 | |
| 438 | /* Remote access is safe as the CPU is dead already */ |
| 439 | percpu_pool = per_cpu_ptr(&percpu_obj_pool, cpu); |
| 440 | hlist_for_each_entry_safe(obj, tmp, &percpu_pool->free_objs, node) { |
| 441 | hlist_del(&obj->node); |
| 442 | kmem_cache_free(obj_cache, obj); |
| 443 | } |
| 444 | |
| 445 | raw_spin_lock_irqsave(&pool_lock, flags); |
| 446 | obj_pool_used -= percpu_pool->obj_free; |
| 447 | debug_objects_freed += percpu_pool->obj_free; |
| 448 | raw_spin_unlock_irqrestore(&pool_lock, flags); |
| 449 | |
| 450 | percpu_pool->obj_free = 0; |
| 451 | |
| 452 | return 0; |
| 453 | } |
| 454 | #endif |
| 455 | |
| 456 | /* |
| 457 | * We run out of memory. That means we probably have tons of objects |
| 458 | * allocated. |
| 459 | */ |
| 460 | static void debug_objects_oom(void) |
| 461 | { |
| 462 | struct debug_bucket *db = obj_hash; |
| 463 | struct hlist_node *tmp; |
| 464 | HLIST_HEAD(freelist); |
| 465 | struct debug_obj *obj; |
| 466 | unsigned long flags; |
| 467 | int i; |
| 468 | |
| 469 | pr_warn("Out of memory. ODEBUG disabled\n"); |
| 470 | |
| 471 | for (i = 0; i < ODEBUG_HASH_SIZE; i++, db++) { |
| 472 | raw_spin_lock_irqsave(&db->lock, flags); |
| 473 | hlist_move_list(&db->list, &freelist); |
| 474 | raw_spin_unlock_irqrestore(&db->lock, flags); |
| 475 | |
| 476 | /* Now free them */ |
| 477 | hlist_for_each_entry_safe(obj, tmp, &freelist, node) { |
| 478 | hlist_del(&obj->node); |
| 479 | free_object(obj); |
| 480 | } |
| 481 | } |
| 482 | } |
| 483 | |
| 484 | /* |
| 485 | * We use the pfn of the address for the hash. That way we can check |
| 486 | * for freed objects simply by checking the affected bucket. |
| 487 | */ |
| 488 | static struct debug_bucket *get_bucket(unsigned long addr) |
| 489 | { |
| 490 | unsigned long hash; |
| 491 | |
| 492 | hash = hash_long((addr >> ODEBUG_CHUNK_SHIFT), ODEBUG_HASH_BITS); |
| 493 | return &obj_hash[hash]; |
| 494 | } |
| 495 | |
| 496 | static void debug_print_object(struct debug_obj *obj, char *msg) |
| 497 | { |
| 498 | const struct debug_obj_descr *descr = obj->descr; |
| 499 | static int limit; |
| 500 | |
| 501 | if (limit < 5 && descr != descr_test) { |
| 502 | void *hint = descr->debug_hint ? |
| 503 | descr->debug_hint(obj->object) : NULL; |
| 504 | limit++; |
| 505 | WARN(1, KERN_ERR "ODEBUG: %s %s (active state %u) " |
| 506 | "object: %p object type: %s hint: %pS\n", |
| 507 | msg, obj_states[obj->state], obj->astate, |
| 508 | obj->object, descr->name, hint); |
| 509 | } |
| 510 | debug_objects_warnings++; |
| 511 | } |
| 512 | |
| 513 | /* |
| 514 | * Try to repair the damage, so we have a better chance to get useful |
| 515 | * debug output. |
| 516 | */ |
| 517 | static bool |
| 518 | debug_object_fixup(bool (*fixup)(void *addr, enum debug_obj_state state), |
| 519 | void * addr, enum debug_obj_state state) |
| 520 | { |
| 521 | if (fixup && fixup(addr, state)) { |
| 522 | debug_objects_fixups++; |
| 523 | return true; |
| 524 | } |
| 525 | return false; |
| 526 | } |
| 527 | |
| 528 | static void debug_object_is_on_stack(void *addr, int onstack) |
| 529 | { |
| 530 | int is_on_stack; |
| 531 | static int limit; |
| 532 | |
| 533 | if (limit > 4) |
| 534 | return; |
| 535 | |
| 536 | is_on_stack = object_is_on_stack(addr); |
| 537 | if (is_on_stack == onstack) |
| 538 | return; |
| 539 | |
| 540 | limit++; |
| 541 | if (is_on_stack) |
| 542 | pr_warn("object %p is on stack %p, but NOT annotated.\n", addr, |
| 543 | task_stack_page(current)); |
| 544 | else |
| 545 | pr_warn("object %p is NOT on stack %p, but annotated.\n", addr, |
| 546 | task_stack_page(current)); |
| 547 | |
| 548 | WARN_ON(1); |
| 549 | } |
| 550 | |
| 551 | static struct debug_obj *lookup_object_or_alloc(void *addr, struct debug_bucket *b, |
| 552 | const struct debug_obj_descr *descr, |
| 553 | bool onstack, bool alloc_ifstatic) |
| 554 | { |
| 555 | struct debug_obj *obj = lookup_object(addr, b); |
| 556 | enum debug_obj_state state = ODEBUG_STATE_NONE; |
| 557 | |
| 558 | if (likely(obj)) |
| 559 | return obj; |
| 560 | |
| 561 | /* |
| 562 | * debug_object_init() unconditionally allocates untracked |
| 563 | * objects. It does not matter whether it is a static object or |
| 564 | * not. |
| 565 | * |
| 566 | * debug_object_assert_init() and debug_object_activate() allow |
| 567 | * allocation only if the descriptor callback confirms that the |
| 568 | * object is static and considered initialized. For non-static |
| 569 | * objects the allocation needs to be done from the fixup callback. |
| 570 | */ |
| 571 | if (unlikely(alloc_ifstatic)) { |
| 572 | if (!descr->is_static_object || !descr->is_static_object(addr)) |
| 573 | return ERR_PTR(-ENOENT); |
| 574 | /* Statically allocated objects are considered initialized */ |
| 575 | state = ODEBUG_STATE_INIT; |
| 576 | } |
| 577 | |
| 578 | obj = alloc_object(addr, b, descr); |
| 579 | if (likely(obj)) { |
| 580 | obj->state = state; |
| 581 | debug_object_is_on_stack(addr, onstack); |
| 582 | return obj; |
| 583 | } |
| 584 | |
| 585 | /* Out of memory. Do the cleanup outside of the locked region */ |
| 586 | debug_objects_enabled = 0; |
| 587 | return NULL; |
| 588 | } |
| 589 | |
| 590 | static void |
| 591 | __debug_object_init(void *addr, const struct debug_obj_descr *descr, int onstack) |
| 592 | { |
| 593 | enum debug_obj_state state; |
| 594 | struct debug_bucket *db; |
| 595 | struct debug_obj *obj; |
| 596 | unsigned long flags; |
| 597 | |
| 598 | /* |
| 599 | * On RT enabled kernels the pool refill must happen in preemptible |
| 600 | * context: |
| 601 | */ |
| 602 | if (!IS_ENABLED(CONFIG_PREEMPT_RT) || preemptible()) |
| 603 | fill_pool(); |
| 604 | |
| 605 | db = get_bucket((unsigned long) addr); |
| 606 | |
| 607 | raw_spin_lock_irqsave(&db->lock, flags); |
| 608 | |
| 609 | obj = lookup_object_or_alloc(addr, db, descr, onstack, false); |
| 610 | if (unlikely(!obj)) { |
| 611 | raw_spin_unlock_irqrestore(&db->lock, flags); |
| 612 | debug_objects_oom(); |
| 613 | return; |
| 614 | } |
| 615 | |
| 616 | switch (obj->state) { |
| 617 | case ODEBUG_STATE_NONE: |
| 618 | case ODEBUG_STATE_INIT: |
| 619 | case ODEBUG_STATE_INACTIVE: |
| 620 | obj->state = ODEBUG_STATE_INIT; |
| 621 | break; |
| 622 | |
| 623 | case ODEBUG_STATE_ACTIVE: |
| 624 | state = obj->state; |
| 625 | raw_spin_unlock_irqrestore(&db->lock, flags); |
| 626 | debug_print_object(obj, "init"); |
| 627 | debug_object_fixup(descr->fixup_init, addr, state); |
| 628 | return; |
| 629 | |
| 630 | case ODEBUG_STATE_DESTROYED: |
| 631 | raw_spin_unlock_irqrestore(&db->lock, flags); |
| 632 | debug_print_object(obj, "init"); |
| 633 | return; |
| 634 | default: |
| 635 | break; |
| 636 | } |
| 637 | |
| 638 | raw_spin_unlock_irqrestore(&db->lock, flags); |
| 639 | } |
| 640 | |
| 641 | /** |
| 642 | * debug_object_init - debug checks when an object is initialized |
| 643 | * @addr: address of the object |
| 644 | * @descr: pointer to an object specific debug description structure |
| 645 | */ |
| 646 | void debug_object_init(void *addr, const struct debug_obj_descr *descr) |
| 647 | { |
| 648 | if (!debug_objects_enabled) |
| 649 | return; |
| 650 | |
| 651 | __debug_object_init(addr, descr, 0); |
| 652 | } |
| 653 | EXPORT_SYMBOL_GPL(debug_object_init); |
| 654 | |
| 655 | /** |
| 656 | * debug_object_init_on_stack - debug checks when an object on stack is |
| 657 | * initialized |
| 658 | * @addr: address of the object |
| 659 | * @descr: pointer to an object specific debug description structure |
| 660 | */ |
| 661 | void debug_object_init_on_stack(void *addr, const struct debug_obj_descr *descr) |
| 662 | { |
| 663 | if (!debug_objects_enabled) |
| 664 | return; |
| 665 | |
| 666 | __debug_object_init(addr, descr, 1); |
| 667 | } |
| 668 | EXPORT_SYMBOL_GPL(debug_object_init_on_stack); |
| 669 | |
| 670 | /** |
| 671 | * debug_object_activate - debug checks when an object is activated |
| 672 | * @addr: address of the object |
| 673 | * @descr: pointer to an object specific debug description structure |
| 674 | * Returns 0 for success, -EINVAL for check failed. |
| 675 | */ |
| 676 | int debug_object_activate(void *addr, const struct debug_obj_descr *descr) |
| 677 | { |
| 678 | struct debug_obj o = { .object = addr, .state = ODEBUG_STATE_NOTAVAILABLE, .descr = descr }; |
| 679 | enum debug_obj_state state; |
| 680 | struct debug_bucket *db; |
| 681 | struct debug_obj *obj; |
| 682 | unsigned long flags; |
| 683 | int ret; |
| 684 | |
| 685 | if (!debug_objects_enabled) |
| 686 | return 0; |
| 687 | |
| 688 | db = get_bucket((unsigned long) addr); |
| 689 | |
| 690 | raw_spin_lock_irqsave(&db->lock, flags); |
| 691 | |
| 692 | obj = lookup_object_or_alloc(addr, db, descr, false, true); |
| 693 | if (likely(!IS_ERR_OR_NULL(obj))) { |
| 694 | bool print_object = false; |
| 695 | |
| 696 | switch (obj->state) { |
| 697 | case ODEBUG_STATE_INIT: |
| 698 | case ODEBUG_STATE_INACTIVE: |
| 699 | obj->state = ODEBUG_STATE_ACTIVE; |
| 700 | ret = 0; |
| 701 | break; |
| 702 | |
| 703 | case ODEBUG_STATE_ACTIVE: |
| 704 | state = obj->state; |
| 705 | raw_spin_unlock_irqrestore(&db->lock, flags); |
| 706 | debug_print_object(obj, "activate"); |
| 707 | ret = debug_object_fixup(descr->fixup_activate, addr, state); |
| 708 | return ret ? 0 : -EINVAL; |
| 709 | |
| 710 | case ODEBUG_STATE_DESTROYED: |
| 711 | print_object = true; |
| 712 | ret = -EINVAL; |
| 713 | break; |
| 714 | default: |
| 715 | ret = 0; |
| 716 | break; |
| 717 | } |
| 718 | raw_spin_unlock_irqrestore(&db->lock, flags); |
| 719 | if (print_object) |
| 720 | debug_print_object(obj, "activate"); |
| 721 | return ret; |
| 722 | } |
| 723 | |
| 724 | raw_spin_unlock_irqrestore(&db->lock, flags); |
| 725 | |
| 726 | /* If NULL the allocation has hit OOM */ |
| 727 | if (!obj) { |
| 728 | debug_objects_oom(); |
| 729 | return 0; |
| 730 | } |
| 731 | |
| 732 | /* Object is neither static nor tracked. It's not initialized */ |
| 733 | debug_print_object(&o, "activate"); |
| 734 | ret = debug_object_fixup(descr->fixup_activate, addr, ODEBUG_STATE_NOTAVAILABLE); |
| 735 | return ret ? 0 : -EINVAL; |
| 736 | } |
| 737 | EXPORT_SYMBOL_GPL(debug_object_activate); |
| 738 | |
| 739 | /** |
| 740 | * debug_object_deactivate - debug checks when an object is deactivated |
| 741 | * @addr: address of the object |
| 742 | * @descr: pointer to an object specific debug description structure |
| 743 | */ |
| 744 | void debug_object_deactivate(void *addr, const struct debug_obj_descr *descr) |
| 745 | { |
| 746 | struct debug_bucket *db; |
| 747 | struct debug_obj *obj; |
| 748 | unsigned long flags; |
| 749 | bool print_object = false; |
| 750 | |
| 751 | if (!debug_objects_enabled) |
| 752 | return; |
| 753 | |
| 754 | db = get_bucket((unsigned long) addr); |
| 755 | |
| 756 | raw_spin_lock_irqsave(&db->lock, flags); |
| 757 | |
| 758 | obj = lookup_object(addr, db); |
| 759 | if (obj) { |
| 760 | switch (obj->state) { |
| 761 | case ODEBUG_STATE_INIT: |
| 762 | case ODEBUG_STATE_INACTIVE: |
| 763 | case ODEBUG_STATE_ACTIVE: |
| 764 | if (!obj->astate) |
| 765 | obj->state = ODEBUG_STATE_INACTIVE; |
| 766 | else |
| 767 | print_object = true; |
| 768 | break; |
| 769 | |
| 770 | case ODEBUG_STATE_DESTROYED: |
| 771 | print_object = true; |
| 772 | break; |
| 773 | default: |
| 774 | break; |
| 775 | } |
| 776 | } |
| 777 | |
| 778 | raw_spin_unlock_irqrestore(&db->lock, flags); |
| 779 | if (!obj) { |
| 780 | struct debug_obj o = { .object = addr, |
| 781 | .state = ODEBUG_STATE_NOTAVAILABLE, |
| 782 | .descr = descr }; |
| 783 | |
| 784 | debug_print_object(&o, "deactivate"); |
| 785 | } else if (print_object) { |
| 786 | debug_print_object(obj, "deactivate"); |
| 787 | } |
| 788 | } |
| 789 | EXPORT_SYMBOL_GPL(debug_object_deactivate); |
| 790 | |
| 791 | /** |
| 792 | * debug_object_destroy - debug checks when an object is destroyed |
| 793 | * @addr: address of the object |
| 794 | * @descr: pointer to an object specific debug description structure |
| 795 | */ |
| 796 | void debug_object_destroy(void *addr, const struct debug_obj_descr *descr) |
| 797 | { |
| 798 | enum debug_obj_state state; |
| 799 | struct debug_bucket *db; |
| 800 | struct debug_obj *obj; |
| 801 | unsigned long flags; |
| 802 | bool print_object = false; |
| 803 | |
| 804 | if (!debug_objects_enabled) |
| 805 | return; |
| 806 | |
| 807 | db = get_bucket((unsigned long) addr); |
| 808 | |
| 809 | raw_spin_lock_irqsave(&db->lock, flags); |
| 810 | |
| 811 | obj = lookup_object(addr, db); |
| 812 | if (!obj) |
| 813 | goto out_unlock; |
| 814 | |
| 815 | switch (obj->state) { |
| 816 | case ODEBUG_STATE_NONE: |
| 817 | case ODEBUG_STATE_INIT: |
| 818 | case ODEBUG_STATE_INACTIVE: |
| 819 | obj->state = ODEBUG_STATE_DESTROYED; |
| 820 | break; |
| 821 | case ODEBUG_STATE_ACTIVE: |
| 822 | state = obj->state; |
| 823 | raw_spin_unlock_irqrestore(&db->lock, flags); |
| 824 | debug_print_object(obj, "destroy"); |
| 825 | debug_object_fixup(descr->fixup_destroy, addr, state); |
| 826 | return; |
| 827 | |
| 828 | case ODEBUG_STATE_DESTROYED: |
| 829 | print_object = true; |
| 830 | break; |
| 831 | default: |
| 832 | break; |
| 833 | } |
| 834 | out_unlock: |
| 835 | raw_spin_unlock_irqrestore(&db->lock, flags); |
| 836 | if (print_object) |
| 837 | debug_print_object(obj, "destroy"); |
| 838 | } |
| 839 | EXPORT_SYMBOL_GPL(debug_object_destroy); |
| 840 | |
| 841 | /** |
| 842 | * debug_object_free - debug checks when an object is freed |
| 843 | * @addr: address of the object |
| 844 | * @descr: pointer to an object specific debug description structure |
| 845 | */ |
| 846 | void debug_object_free(void *addr, const struct debug_obj_descr *descr) |
| 847 | { |
| 848 | enum debug_obj_state state; |
| 849 | struct debug_bucket *db; |
| 850 | struct debug_obj *obj; |
| 851 | unsigned long flags; |
| 852 | |
| 853 | if (!debug_objects_enabled) |
| 854 | return; |
| 855 | |
| 856 | db = get_bucket((unsigned long) addr); |
| 857 | |
| 858 | raw_spin_lock_irqsave(&db->lock, flags); |
| 859 | |
| 860 | obj = lookup_object(addr, db); |
| 861 | if (!obj) |
| 862 | goto out_unlock; |
| 863 | |
| 864 | switch (obj->state) { |
| 865 | case ODEBUG_STATE_ACTIVE: |
| 866 | state = obj->state; |
| 867 | raw_spin_unlock_irqrestore(&db->lock, flags); |
| 868 | debug_print_object(obj, "free"); |
| 869 | debug_object_fixup(descr->fixup_free, addr, state); |
| 870 | return; |
| 871 | default: |
| 872 | hlist_del(&obj->node); |
| 873 | raw_spin_unlock_irqrestore(&db->lock, flags); |
| 874 | free_object(obj); |
| 875 | return; |
| 876 | } |
| 877 | out_unlock: |
| 878 | raw_spin_unlock_irqrestore(&db->lock, flags); |
| 879 | } |
| 880 | EXPORT_SYMBOL_GPL(debug_object_free); |
| 881 | |
| 882 | /** |
| 883 | * debug_object_assert_init - debug checks when object should be init-ed |
| 884 | * @addr: address of the object |
| 885 | * @descr: pointer to an object specific debug description structure |
| 886 | */ |
| 887 | void debug_object_assert_init(void *addr, const struct debug_obj_descr *descr) |
| 888 | { |
| 889 | struct debug_obj o = { .object = addr, .state = ODEBUG_STATE_NOTAVAILABLE, .descr = descr }; |
| 890 | struct debug_bucket *db; |
| 891 | struct debug_obj *obj; |
| 892 | unsigned long flags; |
| 893 | |
| 894 | if (!debug_objects_enabled) |
| 895 | return; |
| 896 | |
| 897 | db = get_bucket((unsigned long) addr); |
| 898 | |
| 899 | raw_spin_lock_irqsave(&db->lock, flags); |
| 900 | obj = lookup_object_or_alloc(addr, db, descr, false, true); |
| 901 | raw_spin_unlock_irqrestore(&db->lock, flags); |
| 902 | if (likely(!IS_ERR_OR_NULL(obj))) |
| 903 | return; |
| 904 | |
| 905 | /* If NULL the allocation has hit OOM */ |
| 906 | if (!obj) { |
| 907 | debug_objects_oom(); |
| 908 | return; |
| 909 | } |
| 910 | |
| 911 | /* Object is neither tracked nor static. It's not initialized. */ |
| 912 | debug_print_object(&o, "assert_init"); |
| 913 | debug_object_fixup(descr->fixup_assert_init, addr, ODEBUG_STATE_NOTAVAILABLE); |
| 914 | } |
| 915 | EXPORT_SYMBOL_GPL(debug_object_assert_init); |
| 916 | |
| 917 | /** |
| 918 | * debug_object_active_state - debug checks object usage state machine |
| 919 | * @addr: address of the object |
| 920 | * @descr: pointer to an object specific debug description structure |
| 921 | * @expect: expected state |
| 922 | * @next: state to move to if expected state is found |
| 923 | */ |
| 924 | void |
| 925 | debug_object_active_state(void *addr, const struct debug_obj_descr *descr, |
| 926 | unsigned int expect, unsigned int next) |
| 927 | { |
| 928 | struct debug_bucket *db; |
| 929 | struct debug_obj *obj; |
| 930 | unsigned long flags; |
| 931 | bool print_object = false; |
| 932 | |
| 933 | if (!debug_objects_enabled) |
| 934 | return; |
| 935 | |
| 936 | db = get_bucket((unsigned long) addr); |
| 937 | |
| 938 | raw_spin_lock_irqsave(&db->lock, flags); |
| 939 | |
| 940 | obj = lookup_object(addr, db); |
| 941 | if (obj) { |
| 942 | switch (obj->state) { |
| 943 | case ODEBUG_STATE_ACTIVE: |
| 944 | if (obj->astate == expect) |
| 945 | obj->astate = next; |
| 946 | else |
| 947 | print_object = true; |
| 948 | break; |
| 949 | |
| 950 | default: |
| 951 | print_object = true; |
| 952 | break; |
| 953 | } |
| 954 | } |
| 955 | |
| 956 | raw_spin_unlock_irqrestore(&db->lock, flags); |
| 957 | if (!obj) { |
| 958 | struct debug_obj o = { .object = addr, |
| 959 | .state = ODEBUG_STATE_NOTAVAILABLE, |
| 960 | .descr = descr }; |
| 961 | |
| 962 | debug_print_object(&o, "active_state"); |
| 963 | } else if (print_object) { |
| 964 | debug_print_object(obj, "active_state"); |
| 965 | } |
| 966 | } |
| 967 | EXPORT_SYMBOL_GPL(debug_object_active_state); |
| 968 | |
| 969 | #ifdef CONFIG_DEBUG_OBJECTS_FREE |
| 970 | static void __debug_check_no_obj_freed(const void *address, unsigned long size) |
| 971 | { |
| 972 | unsigned long flags, oaddr, saddr, eaddr, paddr, chunks; |
| 973 | const struct debug_obj_descr *descr; |
| 974 | enum debug_obj_state state; |
| 975 | struct debug_bucket *db; |
| 976 | struct hlist_node *tmp; |
| 977 | struct debug_obj *obj; |
| 978 | int cnt, objs_checked = 0; |
| 979 | |
| 980 | saddr = (unsigned long) address; |
| 981 | eaddr = saddr + size; |
| 982 | paddr = saddr & ODEBUG_CHUNK_MASK; |
| 983 | chunks = ((eaddr - paddr) + (ODEBUG_CHUNK_SIZE - 1)); |
| 984 | chunks >>= ODEBUG_CHUNK_SHIFT; |
| 985 | |
| 986 | for (;chunks > 0; chunks--, paddr += ODEBUG_CHUNK_SIZE) { |
| 987 | db = get_bucket(paddr); |
| 988 | |
| 989 | repeat: |
| 990 | cnt = 0; |
| 991 | raw_spin_lock_irqsave(&db->lock, flags); |
| 992 | hlist_for_each_entry_safe(obj, tmp, &db->list, node) { |
| 993 | cnt++; |
| 994 | oaddr = (unsigned long) obj->object; |
| 995 | if (oaddr < saddr || oaddr >= eaddr) |
| 996 | continue; |
| 997 | |
| 998 | switch (obj->state) { |
| 999 | case ODEBUG_STATE_ACTIVE: |
| 1000 | descr = obj->descr; |
| 1001 | state = obj->state; |
| 1002 | raw_spin_unlock_irqrestore(&db->lock, flags); |
| 1003 | debug_print_object(obj, "free"); |
| 1004 | debug_object_fixup(descr->fixup_free, |
| 1005 | (void *) oaddr, state); |
| 1006 | goto repeat; |
| 1007 | default: |
| 1008 | hlist_del(&obj->node); |
| 1009 | __free_object(obj); |
| 1010 | break; |
| 1011 | } |
| 1012 | } |
| 1013 | raw_spin_unlock_irqrestore(&db->lock, flags); |
| 1014 | |
| 1015 | if (cnt > debug_objects_maxchain) |
| 1016 | debug_objects_maxchain = cnt; |
| 1017 | |
| 1018 | objs_checked += cnt; |
| 1019 | } |
| 1020 | |
| 1021 | if (objs_checked > debug_objects_maxchecked) |
| 1022 | debug_objects_maxchecked = objs_checked; |
| 1023 | |
| 1024 | /* Schedule work to actually kmem_cache_free() objects */ |
| 1025 | if (!READ_ONCE(obj_freeing) && READ_ONCE(obj_nr_tofree)) { |
| 1026 | WRITE_ONCE(obj_freeing, true); |
| 1027 | schedule_delayed_work(&debug_obj_work, ODEBUG_FREE_WORK_DELAY); |
| 1028 | } |
| 1029 | } |
| 1030 | |
| 1031 | void debug_check_no_obj_freed(const void *address, unsigned long size) |
| 1032 | { |
| 1033 | if (debug_objects_enabled) |
| 1034 | __debug_check_no_obj_freed(address, size); |
| 1035 | } |
| 1036 | #endif |
| 1037 | |
| 1038 | #ifdef CONFIG_DEBUG_FS |
| 1039 | |
| 1040 | static int debug_stats_show(struct seq_file *m, void *v) |
| 1041 | { |
| 1042 | int cpu, obj_percpu_free = 0; |
| 1043 | |
| 1044 | for_each_possible_cpu(cpu) |
| 1045 | obj_percpu_free += per_cpu(percpu_obj_pool.obj_free, cpu); |
| 1046 | |
| 1047 | seq_printf(m, "max_chain :%d\n", debug_objects_maxchain); |
| 1048 | seq_printf(m, "max_checked :%d\n", debug_objects_maxchecked); |
| 1049 | seq_printf(m, "warnings :%d\n", debug_objects_warnings); |
| 1050 | seq_printf(m, "fixups :%d\n", debug_objects_fixups); |
| 1051 | seq_printf(m, "pool_free :%d\n", READ_ONCE(obj_pool_free) + obj_percpu_free); |
| 1052 | seq_printf(m, "pool_pcp_free :%d\n", obj_percpu_free); |
| 1053 | seq_printf(m, "pool_min_free :%d\n", obj_pool_min_free); |
| 1054 | seq_printf(m, "pool_used :%d\n", obj_pool_used - obj_percpu_free); |
| 1055 | seq_printf(m, "pool_max_used :%d\n", obj_pool_max_used); |
| 1056 | seq_printf(m, "on_free_list :%d\n", READ_ONCE(obj_nr_tofree)); |
| 1057 | seq_printf(m, "objs_allocated:%d\n", debug_objects_allocated); |
| 1058 | seq_printf(m, "objs_freed :%d\n", debug_objects_freed); |
| 1059 | return 0; |
| 1060 | } |
| 1061 | DEFINE_SHOW_ATTRIBUTE(debug_stats); |
| 1062 | |
| 1063 | static int __init debug_objects_init_debugfs(void) |
| 1064 | { |
| 1065 | struct dentry *dbgdir; |
| 1066 | |
| 1067 | if (!debug_objects_enabled) |
| 1068 | return 0; |
| 1069 | |
| 1070 | dbgdir = debugfs_create_dir("debug_objects", NULL); |
| 1071 | |
| 1072 | debugfs_create_file("stats", 0444, dbgdir, NULL, &debug_stats_fops); |
| 1073 | |
| 1074 | return 0; |
| 1075 | } |
| 1076 | __initcall(debug_objects_init_debugfs); |
| 1077 | |
| 1078 | #else |
| 1079 | static inline void debug_objects_init_debugfs(void) { } |
| 1080 | #endif |
| 1081 | |
| 1082 | #ifdef CONFIG_DEBUG_OBJECTS_SELFTEST |
| 1083 | |
| 1084 | /* Random data structure for the self test */ |
| 1085 | struct self_test { |
| 1086 | unsigned long dummy1[6]; |
| 1087 | int static_init; |
| 1088 | unsigned long dummy2[3]; |
| 1089 | }; |
| 1090 | |
| 1091 | static __initconst const struct debug_obj_descr descr_type_test; |
| 1092 | |
| 1093 | static bool __init is_static_object(void *addr) |
| 1094 | { |
| 1095 | struct self_test *obj = addr; |
| 1096 | |
| 1097 | return obj->static_init; |
| 1098 | } |
| 1099 | |
| 1100 | /* |
| 1101 | * fixup_init is called when: |
| 1102 | * - an active object is initialized |
| 1103 | */ |
| 1104 | static bool __init fixup_init(void *addr, enum debug_obj_state state) |
| 1105 | { |
| 1106 | struct self_test *obj = addr; |
| 1107 | |
| 1108 | switch (state) { |
| 1109 | case ODEBUG_STATE_ACTIVE: |
| 1110 | debug_object_deactivate(obj, &descr_type_test); |
| 1111 | debug_object_init(obj, &descr_type_test); |
| 1112 | return true; |
| 1113 | default: |
| 1114 | return false; |
| 1115 | } |
| 1116 | } |
| 1117 | |
| 1118 | /* |
| 1119 | * fixup_activate is called when: |
| 1120 | * - an active object is activated |
| 1121 | * - an unknown non-static object is activated |
| 1122 | */ |
| 1123 | static bool __init fixup_activate(void *addr, enum debug_obj_state state) |
| 1124 | { |
| 1125 | struct self_test *obj = addr; |
| 1126 | |
| 1127 | switch (state) { |
| 1128 | case ODEBUG_STATE_NOTAVAILABLE: |
| 1129 | return true; |
| 1130 | case ODEBUG_STATE_ACTIVE: |
| 1131 | debug_object_deactivate(obj, &descr_type_test); |
| 1132 | debug_object_activate(obj, &descr_type_test); |
| 1133 | return true; |
| 1134 | |
| 1135 | default: |
| 1136 | return false; |
| 1137 | } |
| 1138 | } |
| 1139 | |
| 1140 | /* |
| 1141 | * fixup_destroy is called when: |
| 1142 | * - an active object is destroyed |
| 1143 | */ |
| 1144 | static bool __init fixup_destroy(void *addr, enum debug_obj_state state) |
| 1145 | { |
| 1146 | struct self_test *obj = addr; |
| 1147 | |
| 1148 | switch (state) { |
| 1149 | case ODEBUG_STATE_ACTIVE: |
| 1150 | debug_object_deactivate(obj, &descr_type_test); |
| 1151 | debug_object_destroy(obj, &descr_type_test); |
| 1152 | return true; |
| 1153 | default: |
| 1154 | return false; |
| 1155 | } |
| 1156 | } |
| 1157 | |
| 1158 | /* |
| 1159 | * fixup_free is called when: |
| 1160 | * - an active object is freed |
| 1161 | */ |
| 1162 | static bool __init fixup_free(void *addr, enum debug_obj_state state) |
| 1163 | { |
| 1164 | struct self_test *obj = addr; |
| 1165 | |
| 1166 | switch (state) { |
| 1167 | case ODEBUG_STATE_ACTIVE: |
| 1168 | debug_object_deactivate(obj, &descr_type_test); |
| 1169 | debug_object_free(obj, &descr_type_test); |
| 1170 | return true; |
| 1171 | default: |
| 1172 | return false; |
| 1173 | } |
| 1174 | } |
| 1175 | |
| 1176 | static int __init |
| 1177 | check_results(void *addr, enum debug_obj_state state, int fixups, int warnings) |
| 1178 | { |
| 1179 | struct debug_bucket *db; |
| 1180 | struct debug_obj *obj; |
| 1181 | unsigned long flags; |
| 1182 | int res = -EINVAL; |
| 1183 | |
| 1184 | db = get_bucket((unsigned long) addr); |
| 1185 | |
| 1186 | raw_spin_lock_irqsave(&db->lock, flags); |
| 1187 | |
| 1188 | obj = lookup_object(addr, db); |
| 1189 | if (!obj && state != ODEBUG_STATE_NONE) { |
| 1190 | WARN(1, KERN_ERR "ODEBUG: selftest object not found\n"); |
| 1191 | goto out; |
| 1192 | } |
| 1193 | if (obj && obj->state != state) { |
| 1194 | WARN(1, KERN_ERR "ODEBUG: selftest wrong state: %d != %d\n", |
| 1195 | obj->state, state); |
| 1196 | goto out; |
| 1197 | } |
| 1198 | if (fixups != debug_objects_fixups) { |
| 1199 | WARN(1, KERN_ERR "ODEBUG: selftest fixups failed %d != %d\n", |
| 1200 | fixups, debug_objects_fixups); |
| 1201 | goto out; |
| 1202 | } |
| 1203 | if (warnings != debug_objects_warnings) { |
| 1204 | WARN(1, KERN_ERR "ODEBUG: selftest warnings failed %d != %d\n", |
| 1205 | warnings, debug_objects_warnings); |
| 1206 | goto out; |
| 1207 | } |
| 1208 | res = 0; |
| 1209 | out: |
| 1210 | raw_spin_unlock_irqrestore(&db->lock, flags); |
| 1211 | if (res) |
| 1212 | debug_objects_enabled = 0; |
| 1213 | return res; |
| 1214 | } |
| 1215 | |
| 1216 | static __initconst const struct debug_obj_descr descr_type_test = { |
| 1217 | .name = "selftest", |
| 1218 | .is_static_object = is_static_object, |
| 1219 | .fixup_init = fixup_init, |
| 1220 | .fixup_activate = fixup_activate, |
| 1221 | .fixup_destroy = fixup_destroy, |
| 1222 | .fixup_free = fixup_free, |
| 1223 | }; |
| 1224 | |
| 1225 | static __initdata struct self_test obj = { .static_init = 0 }; |
| 1226 | |
| 1227 | static void __init debug_objects_selftest(void) |
| 1228 | { |
| 1229 | int fixups, oldfixups, warnings, oldwarnings; |
| 1230 | unsigned long flags; |
| 1231 | |
| 1232 | local_irq_save(flags); |
| 1233 | |
| 1234 | fixups = oldfixups = debug_objects_fixups; |
| 1235 | warnings = oldwarnings = debug_objects_warnings; |
| 1236 | descr_test = &descr_type_test; |
| 1237 | |
| 1238 | debug_object_init(&obj, &descr_type_test); |
| 1239 | if (check_results(&obj, ODEBUG_STATE_INIT, fixups, warnings)) |
| 1240 | goto out; |
| 1241 | debug_object_activate(&obj, &descr_type_test); |
| 1242 | if (check_results(&obj, ODEBUG_STATE_ACTIVE, fixups, warnings)) |
| 1243 | goto out; |
| 1244 | debug_object_activate(&obj, &descr_type_test); |
| 1245 | if (check_results(&obj, ODEBUG_STATE_ACTIVE, ++fixups, ++warnings)) |
| 1246 | goto out; |
| 1247 | debug_object_deactivate(&obj, &descr_type_test); |
| 1248 | if (check_results(&obj, ODEBUG_STATE_INACTIVE, fixups, warnings)) |
| 1249 | goto out; |
| 1250 | debug_object_destroy(&obj, &descr_type_test); |
| 1251 | if (check_results(&obj, ODEBUG_STATE_DESTROYED, fixups, warnings)) |
| 1252 | goto out; |
| 1253 | debug_object_init(&obj, &descr_type_test); |
| 1254 | if (check_results(&obj, ODEBUG_STATE_DESTROYED, fixups, ++warnings)) |
| 1255 | goto out; |
| 1256 | debug_object_activate(&obj, &descr_type_test); |
| 1257 | if (check_results(&obj, ODEBUG_STATE_DESTROYED, fixups, ++warnings)) |
| 1258 | goto out; |
| 1259 | debug_object_deactivate(&obj, &descr_type_test); |
| 1260 | if (check_results(&obj, ODEBUG_STATE_DESTROYED, fixups, ++warnings)) |
| 1261 | goto out; |
| 1262 | debug_object_free(&obj, &descr_type_test); |
| 1263 | if (check_results(&obj, ODEBUG_STATE_NONE, fixups, warnings)) |
| 1264 | goto out; |
| 1265 | |
| 1266 | obj.static_init = 1; |
| 1267 | debug_object_activate(&obj, &descr_type_test); |
| 1268 | if (check_results(&obj, ODEBUG_STATE_ACTIVE, fixups, warnings)) |
| 1269 | goto out; |
| 1270 | debug_object_init(&obj, &descr_type_test); |
| 1271 | if (check_results(&obj, ODEBUG_STATE_INIT, ++fixups, ++warnings)) |
| 1272 | goto out; |
| 1273 | debug_object_free(&obj, &descr_type_test); |
| 1274 | if (check_results(&obj, ODEBUG_STATE_NONE, fixups, warnings)) |
| 1275 | goto out; |
| 1276 | |
| 1277 | #ifdef CONFIG_DEBUG_OBJECTS_FREE |
| 1278 | debug_object_init(&obj, &descr_type_test); |
| 1279 | if (check_results(&obj, ODEBUG_STATE_INIT, fixups, warnings)) |
| 1280 | goto out; |
| 1281 | debug_object_activate(&obj, &descr_type_test); |
| 1282 | if (check_results(&obj, ODEBUG_STATE_ACTIVE, fixups, warnings)) |
| 1283 | goto out; |
| 1284 | __debug_check_no_obj_freed(&obj, sizeof(obj)); |
| 1285 | if (check_results(&obj, ODEBUG_STATE_NONE, ++fixups, ++warnings)) |
| 1286 | goto out; |
| 1287 | #endif |
| 1288 | pr_info("selftest passed\n"); |
| 1289 | |
| 1290 | out: |
| 1291 | debug_objects_fixups = oldfixups; |
| 1292 | debug_objects_warnings = oldwarnings; |
| 1293 | descr_test = NULL; |
| 1294 | |
| 1295 | local_irq_restore(flags); |
| 1296 | } |
| 1297 | #else |
| 1298 | static inline void debug_objects_selftest(void) { } |
| 1299 | #endif |
| 1300 | |
| 1301 | /* |
| 1302 | * Called during early boot to initialize the hash buckets and link |
| 1303 | * the static object pool objects into the poll list. After this call |
| 1304 | * the object tracker is fully operational. |
| 1305 | */ |
| 1306 | void __init debug_objects_early_init(void) |
| 1307 | { |
| 1308 | int i; |
| 1309 | |
| 1310 | for (i = 0; i < ODEBUG_HASH_SIZE; i++) |
| 1311 | raw_spin_lock_init(&obj_hash[i].lock); |
| 1312 | |
| 1313 | for (i = 0; i < ODEBUG_POOL_SIZE; i++) |
| 1314 | hlist_add_head(&obj_static_pool[i].node, &obj_pool); |
| 1315 | } |
| 1316 | |
| 1317 | /* |
| 1318 | * Convert the statically allocated objects to dynamic ones: |
| 1319 | */ |
| 1320 | static int __init debug_objects_replace_static_objects(void) |
| 1321 | { |
| 1322 | struct debug_bucket *db = obj_hash; |
| 1323 | struct hlist_node *tmp; |
| 1324 | struct debug_obj *obj, *new; |
| 1325 | HLIST_HEAD(objects); |
| 1326 | int i, cnt = 0; |
| 1327 | |
| 1328 | for (i = 0; i < ODEBUG_POOL_SIZE; i++) { |
| 1329 | obj = kmem_cache_zalloc(obj_cache, GFP_KERNEL); |
| 1330 | if (!obj) |
| 1331 | goto free; |
| 1332 | hlist_add_head(&obj->node, &objects); |
| 1333 | } |
| 1334 | |
| 1335 | debug_objects_allocated += i; |
| 1336 | |
| 1337 | /* |
| 1338 | * debug_objects_mem_init() is now called early that only one CPU is up |
| 1339 | * and interrupts have been disabled, so it is safe to replace the |
| 1340 | * active object references. |
| 1341 | */ |
| 1342 | |
| 1343 | /* Remove the statically allocated objects from the pool */ |
| 1344 | hlist_for_each_entry_safe(obj, tmp, &obj_pool, node) |
| 1345 | hlist_del(&obj->node); |
| 1346 | /* Move the allocated objects to the pool */ |
| 1347 | hlist_move_list(&objects, &obj_pool); |
| 1348 | |
| 1349 | /* Replace the active object references */ |
| 1350 | for (i = 0; i < ODEBUG_HASH_SIZE; i++, db++) { |
| 1351 | hlist_move_list(&db->list, &objects); |
| 1352 | |
| 1353 | hlist_for_each_entry(obj, &objects, node) { |
| 1354 | new = hlist_entry(obj_pool.first, typeof(*obj), node); |
| 1355 | hlist_del(&new->node); |
| 1356 | /* copy object data */ |
| 1357 | *new = *obj; |
| 1358 | hlist_add_head(&new->node, &db->list); |
| 1359 | cnt++; |
| 1360 | } |
| 1361 | } |
| 1362 | |
| 1363 | pr_debug("%d of %d active objects replaced\n", |
| 1364 | cnt, obj_pool_used); |
| 1365 | return 0; |
| 1366 | free: |
| 1367 | hlist_for_each_entry_safe(obj, tmp, &objects, node) { |
| 1368 | hlist_del(&obj->node); |
| 1369 | kmem_cache_free(obj_cache, obj); |
| 1370 | } |
| 1371 | return -ENOMEM; |
| 1372 | } |
| 1373 | |
| 1374 | /* |
| 1375 | * Called after the kmem_caches are functional to setup a dedicated |
| 1376 | * cache pool, which has the SLAB_DEBUG_OBJECTS flag set. This flag |
| 1377 | * prevents that the debug code is called on kmem_cache_free() for the |
| 1378 | * debug tracker objects to avoid recursive calls. |
| 1379 | */ |
| 1380 | void __init debug_objects_mem_init(void) |
| 1381 | { |
| 1382 | int cpu, extras; |
| 1383 | |
| 1384 | if (!debug_objects_enabled) |
| 1385 | return; |
| 1386 | |
| 1387 | /* |
| 1388 | * Initialize the percpu object pools |
| 1389 | * |
| 1390 | * Initialization is not strictly necessary, but was done for |
| 1391 | * completeness. |
| 1392 | */ |
| 1393 | for_each_possible_cpu(cpu) |
| 1394 | INIT_HLIST_HEAD(&per_cpu(percpu_obj_pool.free_objs, cpu)); |
| 1395 | |
| 1396 | obj_cache = kmem_cache_create("debug_objects_cache", |
| 1397 | sizeof (struct debug_obj), 0, |
| 1398 | SLAB_DEBUG_OBJECTS | SLAB_NOLEAKTRACE, |
| 1399 | NULL); |
| 1400 | |
| 1401 | if (!obj_cache || debug_objects_replace_static_objects()) { |
| 1402 | debug_objects_enabled = 0; |
| 1403 | kmem_cache_destroy(obj_cache); |
| 1404 | pr_warn("out of memory.\n"); |
| 1405 | return; |
| 1406 | } else |
| 1407 | debug_objects_selftest(); |
| 1408 | |
| 1409 | #ifdef CONFIG_HOTPLUG_CPU |
| 1410 | cpuhp_setup_state_nocalls(CPUHP_DEBUG_OBJ_DEAD, "object:offline", NULL, |
| 1411 | object_cpu_offline); |
| 1412 | #endif |
| 1413 | |
| 1414 | /* |
| 1415 | * Increase the thresholds for allocating and freeing objects |
| 1416 | * according to the number of possible CPUs available in the system. |
| 1417 | */ |
| 1418 | extras = num_possible_cpus() * ODEBUG_BATCH_SIZE; |
| 1419 | debug_objects_pool_size += extras; |
| 1420 | debug_objects_pool_min_level += extras; |
| 1421 | } |