diff options
Diffstat (limited to 'lib/debugobjects.c')
| -rw-r--r-- | lib/debugobjects.c | 693 |
1 files changed, 450 insertions, 243 deletions
diff --git a/lib/debugobjects.c b/lib/debugobjects.c index 55437fd5128b..fb12a9bacd2f 100644 --- a/lib/debugobjects.c +++ b/lib/debugobjects.c @@ -1,11 +1,8 @@ +// SPDX-License-Identifier: GPL-2.0 /* * Generic infrastructure for lifetime debugging of objects. * - * Started by Thomas Gleixner - * * Copyright (C) 2008, Thomas Gleixner <tglx@linutronix.de> - * - * For licencing details see kernel-base/COPYING */ #define pr_fmt(fmt) "ODEBUG: " fmt @@ -19,22 +16,44 @@ #include <linux/slab.h> #include <linux/hash.h> #include <linux/kmemleak.h> +#include <linux/cpu.h> #define ODEBUG_HASH_BITS 14 #define ODEBUG_HASH_SIZE (1 << ODEBUG_HASH_BITS) #define ODEBUG_POOL_SIZE 1024 #define ODEBUG_POOL_MIN_LEVEL 256 +#define ODEBUG_POOL_PERCPU_SIZE 64 +#define ODEBUG_BATCH_SIZE 16 #define ODEBUG_CHUNK_SHIFT PAGE_SHIFT #define ODEBUG_CHUNK_SIZE (1 << ODEBUG_CHUNK_SHIFT) #define ODEBUG_CHUNK_MASK (~(ODEBUG_CHUNK_SIZE - 1)) +/* + * We limit the freeing of debug objects via workqueue at a maximum + * frequency of 10Hz and about 1024 objects for each freeing operation. + * So it is freeing at most 10k debug objects per second. + */ +#define ODEBUG_FREE_WORK_MAX 1024 +#define ODEBUG_FREE_WORK_DELAY DIV_ROUND_UP(HZ, 10) + struct debug_bucket { struct hlist_head list; raw_spinlock_t lock; }; +/* + * Debug object percpu free list + * Access is protected by disabling irq + */ +struct debug_percpu_free { + struct hlist_head free_objs; + int obj_free; +}; + +static DEFINE_PER_CPU(struct debug_percpu_free, percpu_obj_pool); + static struct debug_bucket obj_hash[ODEBUG_HASH_SIZE]; static struct debug_obj obj_static_pool[ODEBUG_POOL_SIZE] __initdata; @@ -44,13 +63,20 @@ static DEFINE_RAW_SPINLOCK(pool_lock); static HLIST_HEAD(obj_pool); static HLIST_HEAD(obj_to_free); +/* + * Because of the presence of percpu free pools, obj_pool_free will + * under-count those in the percpu free pools. Similarly, obj_pool_used + * will over-count those in the percpu free pools. Adjustments will be + * made at debug_stats_show(). Both obj_pool_min_free and obj_pool_max_used + * can be off. + */ static int obj_pool_min_free = ODEBUG_POOL_SIZE; static int obj_pool_free = ODEBUG_POOL_SIZE; static int obj_pool_used; static int obj_pool_max_used; +static bool obj_freeing; /* The number of objs on the global free list */ static int obj_nr_tofree; -static struct kmem_cache *obj_cache; static int debug_objects_maxchain __read_mostly; static int __maybe_unused debug_objects_maxchecked __read_mostly; @@ -62,7 +88,8 @@ static int debug_objects_pool_size __read_mostly = ODEBUG_POOL_SIZE; static int debug_objects_pool_min_level __read_mostly = ODEBUG_POOL_MIN_LEVEL; -static struct debug_obj_descr *descr_test __read_mostly; +static const struct debug_obj_descr *descr_test __read_mostly; +static struct kmem_cache *obj_cache __ro_after_init; /* * Track numbers of kmem_cache_alloc()/free() calls done. @@ -71,7 +98,7 @@ static int debug_objects_allocated; static int debug_objects_freed; static void free_obj_work(struct work_struct *work); -static DECLARE_WORK(debug_obj_work, free_obj_work); +static DECLARE_DELAYED_WORK(debug_obj_work, free_obj_work); static int __init enable_object_debug(char *str) { @@ -99,29 +126,33 @@ static const char *obj_states[ODEBUG_STATE_MAX] = { static void fill_pool(void) { - gfp_t gfp = GFP_ATOMIC | __GFP_NORETRY | __GFP_NOWARN; - struct debug_obj *new, *obj; + gfp_t gfp = __GFP_HIGH | __GFP_NOWARN; + struct debug_obj *obj; unsigned long flags; - if (likely(obj_pool_free >= debug_objects_pool_min_level)) + if (likely(READ_ONCE(obj_pool_free) >= debug_objects_pool_min_level)) return; /* * Reuse objs from the global free list; they will be reinitialized * when allocating. + * + * Both obj_nr_tofree and obj_pool_free are checked locklessly; the + * READ_ONCE()s pair with the WRITE_ONCE()s in pool_lock critical + * sections. */ - while (obj_nr_tofree && (obj_pool_free < obj_pool_min_free)) { + while (READ_ONCE(obj_nr_tofree) && (READ_ONCE(obj_pool_free) < obj_pool_min_free)) { raw_spin_lock_irqsave(&pool_lock, flags); /* * Recheck with the lock held as the worker thread might have * won the race and freed the global free list already. */ - if (obj_nr_tofree) { + while (obj_nr_tofree && (obj_pool_free < obj_pool_min_free)) { obj = hlist_entry(obj_to_free.first, typeof(*obj), node); hlist_del(&obj->node); - obj_nr_tofree--; + WRITE_ONCE(obj_nr_tofree, obj_nr_tofree - 1); hlist_add_head(&obj->node, &obj_pool); - obj_pool_free++; + WRITE_ONCE(obj_pool_free, obj_pool_free + 1); } raw_spin_unlock_irqrestore(&pool_lock, flags); } @@ -129,16 +160,24 @@ static void fill_pool(void) if (unlikely(!obj_cache)) return; - while (obj_pool_free < debug_objects_pool_min_level) { + while (READ_ONCE(obj_pool_free) < debug_objects_pool_min_level) { + struct debug_obj *new[ODEBUG_BATCH_SIZE]; + int cnt; - new = kmem_cache_zalloc(obj_cache, gfp); - if (!new) + for (cnt = 0; cnt < ODEBUG_BATCH_SIZE; cnt++) { + new[cnt] = kmem_cache_zalloc(obj_cache, gfp); + if (!new[cnt]) + break; + } + if (!cnt) return; raw_spin_lock_irqsave(&pool_lock, flags); - hlist_add_head(&new->node, &obj_pool); - debug_objects_allocated++; - obj_pool_free++; + while (cnt) { + hlist_add_head(&new[--cnt]->node, &obj_pool); + debug_objects_allocated++; + WRITE_ONCE(obj_pool_free, obj_pool_free + 1); + } raw_spin_unlock_irqrestore(&pool_lock, flags); } } @@ -163,36 +202,77 @@ static struct debug_obj *lookup_object(void *addr, struct debug_bucket *b) } /* - * Allocate a new object. If the pool is empty, switch off the debugger. - * Must be called with interrupts disabled. + * Allocate a new object from the hlist */ -static struct debug_obj * -alloc_object(void *addr, struct debug_bucket *b, struct debug_obj_descr *descr) +static struct debug_obj *__alloc_object(struct hlist_head *list) { struct debug_obj *obj = NULL; - raw_spin_lock(&pool_lock); - if (obj_pool.first) { - obj = hlist_entry(obj_pool.first, typeof(*obj), node); - - obj->object = addr; - obj->descr = descr; - obj->state = ODEBUG_STATE_NONE; - obj->astate = 0; + if (list->first) { + obj = hlist_entry(list->first, typeof(*obj), node); hlist_del(&obj->node); + } - hlist_add_head(&obj->node, &b->list); + return obj; +} + +static struct debug_obj * +alloc_object(void *addr, struct debug_bucket *b, const struct debug_obj_descr *descr) +{ + struct debug_percpu_free *percpu_pool = this_cpu_ptr(&percpu_obj_pool); + struct debug_obj *obj; + if (likely(obj_cache)) { + obj = __alloc_object(&percpu_pool->free_objs); + if (obj) { + percpu_pool->obj_free--; + goto init_obj; + } + } + + raw_spin_lock(&pool_lock); + obj = __alloc_object(&obj_pool); + if (obj) { obj_pool_used++; + WRITE_ONCE(obj_pool_free, obj_pool_free - 1); + + /* + * Looking ahead, allocate one batch of debug objects and + * put them into the percpu free pool. + */ + if (likely(obj_cache)) { + int i; + + for (i = 0; i < ODEBUG_BATCH_SIZE; i++) { + struct debug_obj *obj2; + + obj2 = __alloc_object(&obj_pool); + if (!obj2) + break; + hlist_add_head(&obj2->node, + &percpu_pool->free_objs); + percpu_pool->obj_free++; + obj_pool_used++; + WRITE_ONCE(obj_pool_free, obj_pool_free - 1); + } + } + if (obj_pool_used > obj_pool_max_used) obj_pool_max_used = obj_pool_used; - obj_pool_free--; if (obj_pool_free < obj_pool_min_free) obj_pool_min_free = obj_pool_free; } raw_spin_unlock(&pool_lock); +init_obj: + if (obj) { + obj->object = addr; + obj->descr = descr; + obj->state = ODEBUG_STATE_NONE; + obj->astate = 0; + hlist_add_head(&obj->node, &b->list); + } return obj; } @@ -209,22 +289,31 @@ static void free_obj_work(struct work_struct *work) unsigned long flags; HLIST_HEAD(tofree); + WRITE_ONCE(obj_freeing, false); if (!raw_spin_trylock_irqsave(&pool_lock, flags)) return; + if (obj_pool_free >= debug_objects_pool_size) + goto free_objs; + /* * The objs on the pool list might be allocated before the work is * run, so recheck if pool list it full or not, if not fill pool - * list from the global free list + * list from the global free list. As it is likely that a workload + * may be gearing up to use more and more objects, don't free any + * of them until the next round. */ while (obj_nr_tofree && obj_pool_free < debug_objects_pool_size) { obj = hlist_entry(obj_to_free.first, typeof(*obj), node); hlist_del(&obj->node); hlist_add_head(&obj->node, &obj_pool); - obj_pool_free++; - obj_nr_tofree--; + WRITE_ONCE(obj_pool_free, obj_pool_free + 1); + WRITE_ONCE(obj_nr_tofree, obj_nr_tofree - 1); } + raw_spin_unlock_irqrestore(&pool_lock, flags); + return; +free_objs: /* * Pool list is already full and there are still objs on the free * list. Move remaining free objs to a temporary list to free the @@ -233,7 +322,7 @@ static void free_obj_work(struct work_struct *work) if (obj_nr_tofree) { hlist_move_list(&obj_to_free, &tofree); debug_objects_freed += obj_nr_tofree; - obj_nr_tofree = 0; + WRITE_ONCE(obj_nr_tofree, 0); } raw_spin_unlock_irqrestore(&pool_lock, flags); @@ -243,24 +332,86 @@ static void free_obj_work(struct work_struct *work) } } -static bool __free_object(struct debug_obj *obj) +static void __free_object(struct debug_obj *obj) { + struct debug_obj *objs[ODEBUG_BATCH_SIZE]; + struct debug_percpu_free *percpu_pool; + int lookahead_count = 0; unsigned long flags; bool work; - raw_spin_lock_irqsave(&pool_lock, flags); - work = (obj_pool_free > debug_objects_pool_size) && obj_cache; + local_irq_save(flags); + if (!obj_cache) + goto free_to_obj_pool; + + /* + * Try to free it into the percpu pool first. + */ + percpu_pool = this_cpu_ptr(&percpu_obj_pool); + if (percpu_pool->obj_free < ODEBUG_POOL_PERCPU_SIZE) { + hlist_add_head(&obj->node, &percpu_pool->free_objs); + percpu_pool->obj_free++; + local_irq_restore(flags); + return; + } + + /* + * As the percpu pool is full, look ahead and pull out a batch + * of objects from the percpu pool and free them as well. + */ + for (; lookahead_count < ODEBUG_BATCH_SIZE; lookahead_count++) { + objs[lookahead_count] = __alloc_object(&percpu_pool->free_objs); + if (!objs[lookahead_count]) + break; + percpu_pool->obj_free--; + } + +free_to_obj_pool: + raw_spin_lock(&pool_lock); + work = (obj_pool_free > debug_objects_pool_size) && obj_cache && + (obj_nr_tofree < ODEBUG_FREE_WORK_MAX); obj_pool_used--; if (work) { - obj_nr_tofree++; + WRITE_ONCE(obj_nr_tofree, obj_nr_tofree + 1); hlist_add_head(&obj->node, &obj_to_free); + if (lookahead_count) { + WRITE_ONCE(obj_nr_tofree, obj_nr_tofree + lookahead_count); + obj_pool_used -= lookahead_count; + while (lookahead_count) { + hlist_add_head(&objs[--lookahead_count]->node, + &obj_to_free); + } + } + + if ((obj_pool_free > debug_objects_pool_size) && + (obj_nr_tofree < ODEBUG_FREE_WORK_MAX)) { + int i; + + /* + * Free one more batch of objects from obj_pool. + */ + for (i = 0; i < ODEBUG_BATCH_SIZE; i++) { + obj = __alloc_object(&obj_pool); + hlist_add_head(&obj->node, &obj_to_free); + WRITE_ONCE(obj_pool_free, obj_pool_free - 1); + WRITE_ONCE(obj_nr_tofree, obj_nr_tofree + 1); + } + } } else { - obj_pool_free++; + WRITE_ONCE(obj_pool_free, obj_pool_free + 1); hlist_add_head(&obj->node, &obj_pool); + if (lookahead_count) { + WRITE_ONCE(obj_pool_free, obj_pool_free + lookahead_count); + obj_pool_used -= lookahead_count; + while (lookahead_count) { + hlist_add_head(&objs[--lookahead_count]->node, + &obj_pool); + } + } } - raw_spin_unlock_irqrestore(&pool_lock, flags); - return work; + raw_spin_unlock(&pool_lock); + local_irq_restore(flags); } /* @@ -269,9 +420,38 @@ static bool __free_object(struct debug_obj *obj) */ static void free_object(struct debug_obj *obj) { - if (__free_object(obj)) - schedule_work(&debug_obj_work); + __free_object(obj); + if (!READ_ONCE(obj_freeing) && READ_ONCE(obj_nr_tofree)) { + WRITE_ONCE(obj_freeing, true); + schedule_delayed_work(&debug_obj_work, ODEBUG_FREE_WORK_DELAY); + } +} + +#ifdef CONFIG_HOTPLUG_CPU +static int object_cpu_offline(unsigned int cpu) +{ + struct debug_percpu_free *percpu_pool; + struct hlist_node *tmp; + struct debug_obj *obj; + unsigned long flags; + + /* Remote access is safe as the CPU is dead already */ + percpu_pool = per_cpu_ptr(&percpu_obj_pool, cpu); + hlist_for_each_entry_safe(obj, tmp, &percpu_pool->free_objs, node) { + hlist_del(&obj->node); + kmem_cache_free(obj_cache, obj); + } + + raw_spin_lock_irqsave(&pool_lock, flags); + obj_pool_used -= percpu_pool->obj_free; + debug_objects_freed += percpu_pool->obj_free; + raw_spin_unlock_irqrestore(&pool_lock, flags); + + percpu_pool->obj_free = 0; + + return 0; } +#endif /* * We run out of memory. That means we probably have tons of objects @@ -315,17 +495,26 @@ static struct debug_bucket *get_bucket(unsigned long addr) static void debug_print_object(struct debug_obj *obj, char *msg) { - struct debug_obj_descr *descr = obj->descr; + const struct debug_obj_descr *descr = obj->descr; static int limit; + /* + * Don't report if lookup_object_or_alloc() by the current thread + * failed because lookup_object_or_alloc()/debug_objects_oom() by a + * concurrent thread turned off debug_objects_enabled and cleared + * the hash buckets. + */ + if (!debug_objects_enabled) + return; + if (limit < 5 && descr != descr_test) { void *hint = descr->debug_hint ? descr->debug_hint(obj->object) : NULL; limit++; WARN(1, KERN_ERR "ODEBUG: %s %s (active state %u) " - "object type: %s hint: %pS\n", + "object: %p object type: %s hint: %pS\n", msg, obj_states[obj->state], obj->astate, - descr->name, hint); + obj->object, descr->name, hint); } debug_objects_warnings++; } @@ -368,30 +557,84 @@ static void debug_object_is_on_stack(void *addr, int onstack) WARN_ON(1); } +static struct debug_obj *lookup_object_or_alloc(void *addr, struct debug_bucket *b, + const struct debug_obj_descr *descr, + bool onstack, bool alloc_ifstatic) +{ + struct debug_obj *obj = lookup_object(addr, b); + enum debug_obj_state state = ODEBUG_STATE_NONE; + + if (likely(obj)) + return obj; + + /* + * debug_object_init() unconditionally allocates untracked + * objects. It does not matter whether it is a static object or + * not. + * + * debug_object_assert_init() and debug_object_activate() allow + * allocation only if the descriptor callback confirms that the + * object is static and considered initialized. For non-static + * objects the allocation needs to be done from the fixup callback. + */ + if (unlikely(alloc_ifstatic)) { + if (!descr->is_static_object || !descr->is_static_object(addr)) + return ERR_PTR(-ENOENT); + /* Statically allocated objects are considered initialized */ + state = ODEBUG_STATE_INIT; + } + + obj = alloc_object(addr, b, descr); + if (likely(obj)) { + obj->state = state; + debug_object_is_on_stack(addr, onstack); + return obj; + } + + /* Out of memory. Do the cleanup outside of the locked region */ + debug_objects_enabled = 0; + return NULL; +} + +static void debug_objects_fill_pool(void) +{ + /* + * On RT enabled kernels the pool refill must happen in preemptible + * context -- for !RT kernels we rely on the fact that spinlock_t and + * raw_spinlock_t are basically the same type and this lock-type + * inversion works just fine. + */ + if (!IS_ENABLED(CONFIG_PREEMPT_RT) || preemptible()) { + /* + * Annotate away the spinlock_t inside raw_spinlock_t warning + * by temporarily raising the wait-type to WAIT_SLEEP, matching + * the preemptible() condition above. + */ + static DEFINE_WAIT_OVERRIDE_MAP(fill_pool_map, LD_WAIT_SLEEP); + lock_map_acquire_try(&fill_pool_map); + fill_pool(); + lock_map_release(&fill_pool_map); + } +} + static void -__debug_object_init(void *addr, struct debug_obj_descr *descr, int onstack) +__debug_object_init(void *addr, const struct debug_obj_descr *descr, int onstack) { - enum debug_obj_state state; + struct debug_obj *obj, o; struct debug_bucket *db; - struct debug_obj *obj; unsigned long flags; - fill_pool(); + debug_objects_fill_pool(); db = get_bucket((unsigned long) addr); raw_spin_lock_irqsave(&db->lock, flags); - obj = lookup_object(addr, db); - if (!obj) { - obj = alloc_object(addr, db, descr); - if (!obj) { - debug_objects_enabled = 0; - raw_spin_unlock_irqrestore(&db->lock, flags); - debug_objects_oom(); - return; - } - debug_object_is_on_stack(addr, onstack); + obj = lookup_object_or_alloc(addr, db, descr, onstack, false); + if (unlikely(!obj)) { + raw_spin_unlock_irqrestore(&db->lock, flags); + debug_objects_oom(); + return; } switch (obj->state) { @@ -399,23 +642,18 @@ __debug_object_init(void *addr, struct debug_obj_descr *descr, int onstack) case ODEBUG_STATE_INIT: case ODEBUG_STATE_INACTIVE: obj->state = ODEBUG_STATE_INIT; - break; - - case ODEBUG_STATE_ACTIVE: - debug_print_object(obj, "init"); - state = obj->state; raw_spin_unlock_irqrestore(&db->lock, flags); - debug_object_fixup(descr->fixup_init, addr, state); return; - - case ODEBUG_STATE_DESTROYED: - debug_print_object(obj, "init"); - break; default: break; } + o = *obj; raw_spin_unlock_irqrestore(&db->lock, flags); + debug_print_object(&o, "init"); + + if (o.state == ODEBUG_STATE_ACTIVE) + debug_object_fixup(descr->fixup_init, addr, o.state); } /** @@ -423,7 +661,7 @@ __debug_object_init(void *addr, struct debug_obj_descr *descr, int onstack) * @addr: address of the object * @descr: pointer to an object specific debug description structure */ -void debug_object_init(void *addr, struct debug_obj_descr *descr) +void debug_object_init(void *addr, const struct debug_obj_descr *descr) { if (!debug_objects_enabled) return; @@ -438,7 +676,7 @@ EXPORT_SYMBOL_GPL(debug_object_init); * @addr: address of the object * @descr: pointer to an object specific debug description structure */ -void debug_object_init_on_stack(void *addr, struct debug_obj_descr *descr) +void debug_object_init_on_stack(void *addr, const struct debug_obj_descr *descr) { if (!debug_objects_enabled) return; @@ -453,71 +691,55 @@ EXPORT_SYMBOL_GPL(debug_object_init_on_stack); * @descr: pointer to an object specific debug description structure * Returns 0 for success, -EINVAL for check failed. */ -int debug_object_activate(void *addr, struct debug_obj_descr *descr) +int debug_object_activate(void *addr, const struct debug_obj_descr *descr) { - enum debug_obj_state state; + struct debug_obj o = { .object = addr, .state = ODEBUG_STATE_NOTAVAILABLE, .descr = descr }; struct debug_bucket *db; struct debug_obj *obj; unsigned long flags; - int ret; - struct debug_obj o = { .object = addr, - .state = ODEBUG_STATE_NOTAVAILABLE, - .descr = descr }; if (!debug_objects_enabled) return 0; + debug_objects_fill_pool(); + db = get_bucket((unsigned long) addr); raw_spin_lock_irqsave(&db->lock, flags); - obj = lookup_object(addr, db); - if (obj) { + obj = lookup_object_or_alloc(addr, db, descr, false, true); + if (unlikely(!obj)) { + raw_spin_unlock_irqrestore(&db->lock, flags); + debug_objects_oom(); + return 0; + } else if (likely(!IS_ERR(obj))) { switch (obj->state) { - case ODEBUG_STATE_INIT: - case ODEBUG_STATE_INACTIVE: - obj->state = ODEBUG_STATE_ACTIVE; - ret = 0; - break; - case ODEBUG_STATE_ACTIVE: - debug_print_object(obj, "activate"); - state = obj->state; - raw_spin_unlock_irqrestore(&db->lock, flags); - ret = debug_object_fixup(descr->fixup_activate, addr, state); - return ret ? 0 : -EINVAL; - case ODEBUG_STATE_DESTROYED: - debug_print_object(obj, "activate"); - ret = -EINVAL; + o = *obj; break; + case ODEBUG_STATE_INIT: + case ODEBUG_STATE_INACTIVE: + obj->state = ODEBUG_STATE_ACTIVE; + fallthrough; default: - ret = 0; - break; + raw_spin_unlock_irqrestore(&db->lock, flags); + return 0; } - raw_spin_unlock_irqrestore(&db->lock, flags); - return ret; } raw_spin_unlock_irqrestore(&db->lock, flags); - /* - * We are here when a static object is activated. We - * let the type specific code confirm whether this is - * true or not. if true, we just make sure that the - * static object is tracked in the object tracker. If - * not, this must be a bug, so we try to fix it up. - */ - if (descr->is_static_object && descr->is_static_object(addr)) { - /* track this static object */ - debug_object_init(addr, descr); - debug_object_activate(addr, descr); - } else { - debug_print_object(&o, "activate"); - ret = debug_object_fixup(descr->fixup_activate, addr, - ODEBUG_STATE_NOTAVAILABLE); - return ret ? 0 : -EINVAL; + debug_print_object(&o, "activate"); + + switch (o.state) { + case ODEBUG_STATE_ACTIVE: + case ODEBUG_STATE_NOTAVAILABLE: + if (debug_object_fixup(descr->fixup_activate, addr, o.state)) + return 0; + fallthrough; + default: + return -EINVAL; } - return 0; } EXPORT_SYMBOL_GPL(debug_object_activate); @@ -526,8 +748,9 @@ EXPORT_SYMBOL_GPL(debug_object_activate); * @addr: address of the object * @descr: pointer to an object specific debug description structure */ -void debug_object_deactivate(void *addr, struct debug_obj_descr *descr) +void debug_object_deactivate(void *addr, const struct debug_obj_descr *descr) { + struct debug_obj o = { .object = addr, .state = ODEBUG_STATE_NOTAVAILABLE, .descr = descr }; struct debug_bucket *db; struct debug_obj *obj; unsigned long flags; @@ -542,30 +765,24 @@ void debug_object_deactivate(void *addr, struct debug_obj_descr *descr) obj = lookup_object(addr, db); if (obj) { switch (obj->state) { + case ODEBUG_STATE_DESTROYED: + break; case ODEBUG_STATE_INIT: case ODEBUG_STATE_INACTIVE: case ODEBUG_STATE_ACTIVE: - if (!obj->astate) - obj->state = ODEBUG_STATE_INACTIVE; - else - debug_print_object(obj, "deactivate"); - break; - - case ODEBUG_STATE_DESTROYED: - debug_print_object(obj, "deactivate"); - break; + if (obj->astate) + break; + obj->state = ODEBUG_STATE_INACTIVE; + fallthrough; default: - break; + raw_spin_unlock_irqrestore(&db->lock, flags); + return; } - } else { - struct debug_obj o = { .object = addr, - .state = ODEBUG_STATE_NOTAVAILABLE, - .descr = descr }; - - debug_print_object(&o, "deactivate"); + o = *obj; } raw_spin_unlock_irqrestore(&db->lock, flags); + debug_print_object(&o, "deactivate"); } EXPORT_SYMBOL_GPL(debug_object_deactivate); @@ -574,11 +791,10 @@ EXPORT_SYMBOL_GPL(debug_object_deactivate); * @addr: address of the object * @descr: pointer to an object specific debug description structure */ -void debug_object_destroy(void *addr, struct debug_obj_descr *descr) +void debug_object_destroy(void *addr, const struct debug_obj_descr *descr) { - enum debug_obj_state state; + struct debug_obj *obj, o; struct debug_bucket *db; - struct debug_obj *obj; unsigned long flags; if (!debug_objects_enabled) @@ -589,30 +805,31 @@ void debug_object_destroy(void *addr, struct debug_obj_descr *descr) raw_spin_lock_irqsave(&db->lock, flags); obj = lookup_object(addr, db); - if (!obj) - goto out_unlock; + if (!obj) { + raw_spin_unlock_irqrestore(&db->lock, flags); + return; + } switch (obj->state) { + case ODEBUG_STATE_ACTIVE: + case ODEBUG_STATE_DESTROYED: + break; case ODEBUG_STATE_NONE: case ODEBUG_STATE_INIT: case ODEBUG_STATE_INACTIVE: obj->state = ODEBUG_STATE_DESTROYED; - break; - case ODEBUG_STATE_ACTIVE: - debug_print_object(obj, "destroy"); - state = obj->state; + fallthrough; + default: raw_spin_unlock_irqrestore(&db->lock, flags); - debug_object_fixup(descr->fixup_destroy, addr, state); return; - - case ODEBUG_STATE_DESTROYED: - debug_print_object(obj, "destroy"); - break; - default: - break; } -out_unlock: + + o = *obj; raw_spin_unlock_irqrestore(&db->lock, flags); + debug_print_object(&o, "destroy"); + + if (o.state == ODEBUG_STATE_ACTIVE) + debug_object_fixup(descr->fixup_destroy, addr, o.state); } EXPORT_SYMBOL_GPL(debug_object_destroy); @@ -621,11 +838,10 @@ EXPORT_SYMBOL_GPL(debug_object_destroy); * @addr: address of the object * @descr: pointer to an object specific debug description structure */ -void debug_object_free(void *addr, struct debug_obj_descr *descr) +void debug_object_free(void *addr, const struct debug_obj_descr *descr) { - enum debug_obj_state state; + struct debug_obj *obj, o; struct debug_bucket *db; - struct debug_obj *obj; unsigned long flags; if (!debug_objects_enabled) @@ -636,24 +852,26 @@ void debug_object_free(void *addr, struct debug_obj_descr *descr) raw_spin_lock_irqsave(&db->lock, flags); obj = lookup_object(addr, db); - if (!obj) - goto out_unlock; + if (!obj) { + raw_spin_unlock_irqrestore(&db->lock, flags); + return; + } switch (obj->state) { case ODEBUG_STATE_ACTIVE: - debug_print_object(obj, "free"); - state = obj->state; - raw_spin_unlock_irqrestore(&db->lock, flags); - debug_object_fixup(descr->fixup_free, addr, state); - return; + break; default: hlist_del(&obj->node); raw_spin_unlock_irqrestore(&db->lock, flags); free_object(obj); return; } -out_unlock: + + o = *obj; raw_spin_unlock_irqrestore(&db->lock, flags); + debug_print_object(&o, "free"); + + debug_object_fixup(descr->fixup_free, addr, o.state); } EXPORT_SYMBOL_GPL(debug_object_free); @@ -662,8 +880,9 @@ EXPORT_SYMBOL_GPL(debug_object_free); * @addr: address of the object * @descr: pointer to an object specific debug description structure */ -void debug_object_assert_init(void *addr, struct debug_obj_descr *descr) +void debug_object_assert_init(void *addr, const struct debug_obj_descr *descr) { + struct debug_obj o = { .object = addr, .state = ODEBUG_STATE_NOTAVAILABLE, .descr = descr }; struct debug_bucket *db; struct debug_obj *obj; unsigned long flags; @@ -671,34 +890,25 @@ void debug_object_assert_init(void *addr, struct debug_obj_descr *descr) if (!debug_objects_enabled) return; + debug_objects_fill_pool(); + db = get_bucket((unsigned long) addr); raw_spin_lock_irqsave(&db->lock, flags); + obj = lookup_object_or_alloc(addr, db, descr, false, true); + raw_spin_unlock_irqrestore(&db->lock, flags); + if (likely(!IS_ERR_OR_NULL(obj))) + return; - obj = lookup_object(addr, db); + /* If NULL the allocation has hit OOM */ if (!obj) { - struct debug_obj o = { .object = addr, - .state = ODEBUG_STATE_NOTAVAILABLE, - .descr = descr }; - - raw_spin_unlock_irqrestore(&db->lock, flags); - /* - * Maybe the object is static, and we let the type specific - * code confirm. Track this static object if true, else invoke - * fixup. - */ - if (descr->is_static_object && descr->is_static_object(addr)) { - /* Track this static object */ - debug_object_init(addr, descr); - } else { - debug_print_object(&o, "assert_init"); - debug_object_fixup(descr->fixup_assert_init, addr, - ODEBUG_STATE_NOTAVAILABLE); - } + debug_objects_oom(); return; } - raw_spin_unlock_irqrestore(&db->lock, flags); + /* Object is neither tracked nor static. It's not initialized. */ + debug_print_object(&o, "assert_init"); + debug_object_fixup(descr->fixup_assert_init, addr, ODEBUG_STATE_NOTAVAILABLE); } EXPORT_SYMBOL_GPL(debug_object_assert_init); @@ -710,9 +920,10 @@ EXPORT_SYMBOL_GPL(debug_object_assert_init); * @next: state to move to if expected state is found */ void -debug_object_active_state(void *addr, struct debug_obj_descr *descr, +debug_object_active_state(void *addr, const struct debug_obj_descr *descr, unsigned int expect, unsigned int next) { + struct debug_obj o = { .object = addr, .state = ODEBUG_STATE_NOTAVAILABLE, .descr = descr }; struct debug_bucket *db; struct debug_obj *obj; unsigned long flags; @@ -728,25 +939,19 @@ debug_object_active_state(void *addr, struct debug_obj_descr *descr, if (obj) { switch (obj->state) { case ODEBUG_STATE_ACTIVE: - if (obj->astate == expect) - obj->astate = next; - else - debug_print_object(obj, "active_state"); - break; - + if (obj->astate != expect) + break; + obj->astate = next; + raw_spin_unlock_irqrestore(&db->lock, flags); + return; default: - debug_print_object(obj, "active_state"); break; } - } else { - struct debug_obj o = { .object = addr, - .state = ODEBUG_STATE_NOTAVAILABLE, - .descr = descr }; - - debug_print_object(&o, "active_state"); + o = *obj; } raw_spin_unlock_irqrestore(&db->lock, flags); + debug_print_object(&o, "active_state"); } EXPORT_SYMBOL_GPL(debug_object_active_state); @@ -754,13 +959,10 @@ EXPORT_SYMBOL_GPL(debug_object_active_state); static void __debug_check_no_obj_freed(const void *address, unsigned long size) { unsigned long flags, oaddr, saddr, eaddr, paddr, chunks; - struct debug_obj_descr *descr; - enum debug_obj_state state; + int cnt, objs_checked = 0; + struct debug_obj *obj, o; struct debug_bucket *db; struct hlist_node *tmp; - struct debug_obj *obj; - int cnt, objs_checked = 0; - bool work = false; saddr = (unsigned long) address; eaddr = saddr + size; @@ -782,16 +984,14 @@ repeat: switch (obj->state) { case ODEBUG_STATE_ACTIVE: - debug_print_object(obj, "free"); - descr = obj->descr; - state = obj->state; + o = *obj; raw_spin_unlock_irqrestore(&db->lock, flags); - debug_object_fixup(descr->fixup_free, - (void *) oaddr, state); + debug_print_object(&o, "free"); + debug_object_fixup(o.descr->fixup_free, (void *)oaddr, o.state); goto repeat; default: hlist_del(&obj->node); - work |= __free_object(obj); + __free_object(obj); break; } } @@ -807,8 +1007,10 @@ repeat: debug_objects_maxchecked = objs_checked; /* Schedule work to actually kmem_cache_free() objects */ - if (work) - schedule_work(&debug_obj_work); + if (!READ_ONCE(obj_freeing) && READ_ONCE(obj_nr_tofree)) { + WRITE_ONCE(obj_freeing, true); + schedule_delayed_work(&debug_obj_work, ODEBUG_FREE_WORK_DELAY); + } } void debug_check_no_obj_freed(const void *address, unsigned long size) @@ -822,54 +1024,39 @@ void debug_check_no_obj_freed(const void *address, unsigned long size) static int debug_stats_show(struct seq_file *m, void *v) { + int cpu, obj_percpu_free = 0; + + for_each_possible_cpu(cpu) + obj_percpu_free += per_cpu(percpu_obj_pool.obj_free, cpu); + seq_printf(m, "max_chain :%d\n", debug_objects_maxchain); seq_printf(m, "max_checked :%d\n", debug_objects_maxchecked); seq_printf(m, "warnings :%d\n", debug_objects_warnings); seq_printf(m, "fixups :%d\n", debug_objects_fixups); - seq_printf(m, "pool_free :%d\n", obj_pool_free); + seq_printf(m, "pool_free :%d\n", READ_ONCE(obj_pool_free) + obj_percpu_free); + seq_printf(m, "pool_pcp_free :%d\n", obj_percpu_free); seq_printf(m, "pool_min_free :%d\n", obj_pool_min_free); - seq_printf(m, "pool_used :%d\n", obj_pool_used); + seq_printf(m, "pool_used :%d\n", obj_pool_used - obj_percpu_free); seq_printf(m, "pool_max_used :%d\n", obj_pool_max_used); - seq_printf(m, "on_free_list :%d\n", obj_nr_tofree); + seq_printf(m, "on_free_list :%d\n", READ_ONCE(obj_nr_tofree)); seq_printf(m, "objs_allocated:%d\n", debug_objects_allocated); seq_printf(m, "objs_freed :%d\n", debug_objects_freed); return 0; } - -static int debug_stats_open(struct inode *inode, struct file *filp) -{ - return single_open(filp, debug_stats_show, NULL); -} - -static const struct file_operations debug_stats_fops = { - .open = debug_stats_open, - .read = seq_read, - .llseek = seq_lseek, - .release = single_release, -}; +DEFINE_SHOW_ATTRIBUTE(debug_stats); static int __init debug_objects_init_debugfs(void) { - struct dentry *dbgdir, *dbgstats; + struct dentry *dbgdir; if (!debug_objects_enabled) return 0; dbgdir = debugfs_create_dir("debug_objects", NULL); - if (!dbgdir) - return -ENOMEM; - dbgstats = debugfs_create_file("stats", 0444, dbgdir, NULL, - &debug_stats_fops); - if (!dbgstats) - goto err; + debugfs_create_file("stats", 0444, dbgdir, NULL, &debug_stats_fops); return 0; - -err: - debugfs_remove(dbgdir); - - return -ENOMEM; } __initcall(debug_objects_init_debugfs); @@ -886,7 +1073,7 @@ struct self_test { unsigned long dummy2[3]; }; -static __initdata struct debug_obj_descr descr_type_test; +static __initconst const struct debug_obj_descr descr_type_test; static bool __init is_static_object(void *addr) { @@ -1011,7 +1198,7 @@ out: return res; } -static __initdata struct debug_obj_descr descr_type_test = { +static __initconst const struct debug_obj_descr descr_type_test = { .name = "selftest", .is_static_object = is_static_object, .fixup_init = fixup_init, @@ -1130,6 +1317,8 @@ static int __init debug_objects_replace_static_objects(void) hlist_add_head(&obj->node, &objects); } + debug_objects_allocated += i; + /* * debug_objects_mem_init() is now called early that only one CPU is up * and interrupts have been disabled, so it is safe to replace the @@ -1175,9 +1364,20 @@ free: */ void __init debug_objects_mem_init(void) { + int cpu, extras; + if (!debug_objects_enabled) return; + /* + * Initialize the percpu object pools + * + * Initialization is not strictly necessary, but was done for + * completeness. + */ + for_each_possible_cpu(cpu) + INIT_HLIST_HEAD(&per_cpu(percpu_obj_pool.free_objs, cpu)); + obj_cache = kmem_cache_create("debug_objects_cache", sizeof (struct debug_obj), 0, SLAB_DEBUG_OBJECTS | SLAB_NOLEAKTRACE, @@ -1187,13 +1387,20 @@ void __init debug_objects_mem_init(void) debug_objects_enabled = 0; kmem_cache_destroy(obj_cache); pr_warn("out of memory.\n"); + return; } else debug_objects_selftest(); +#ifdef CONFIG_HOTPLUG_CPU + cpuhp_setup_state_nocalls(CPUHP_DEBUG_OBJ_DEAD, "object:offline", NULL, + object_cpu_offline); +#endif + /* * Increase the thresholds for allocating and freeing objects * according to the number of possible CPUs available in the system. */ - debug_objects_pool_size += num_possible_cpus() * 32; - debug_objects_pool_min_level += num_possible_cpus() * 4; + extras = num_possible_cpus() * ODEBUG_BATCH_SIZE; + debug_objects_pool_size += extras; + debug_objects_pool_min_level += extras; } |