diff options
Diffstat (limited to 'lib/debugobjects.c')
-rw-r--r-- | lib/debugobjects.c | 312 |
1 files changed, 213 insertions, 99 deletions
diff --git a/lib/debugobjects.c b/lib/debugobjects.c index e28481c402ae..62d095fd0c52 100644 --- a/lib/debugobjects.c +++ b/lib/debugobjects.c @@ -25,6 +25,7 @@ #define ODEBUG_POOL_SIZE 1024 #define ODEBUG_POOL_MIN_LEVEL 256 +#define ODEBUG_POOL_PERCPU_SIZE 64 #define ODEBUG_CHUNK_SHIFT PAGE_SHIFT #define ODEBUG_CHUNK_SIZE (1 << ODEBUG_CHUNK_SHIFT) @@ -35,6 +36,17 @@ struct debug_bucket { 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 +56,19 @@ 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; /* 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; @@ -63,6 +81,7 @@ static int debug_objects_pool_size __read_mostly static int debug_objects_pool_min_level __read_mostly = ODEBUG_POOL_MIN_LEVEL; static struct debug_obj_descr *descr_test __read_mostly; +static struct kmem_cache *obj_cache __read_mostly; /* * Track numbers of kmem_cache_alloc()/free() calls done. @@ -163,26 +182,38 @@ 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, struct debug_obj_descr *descr) +{ + struct debug_percpu_free *percpu_pool; + struct debug_obj *obj; + + if (likely(obj_cache)) { + percpu_pool = this_cpu_ptr(&percpu_obj_pool); + 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++; if (obj_pool_used > obj_pool_max_used) obj_pool_max_used = obj_pool_used; @@ -193,6 +224,14 @@ alloc_object(void *addr, struct debug_bucket *b, struct debug_obj_descr *descr) } 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; } @@ -247,8 +286,21 @@ static bool __free_object(struct debug_obj *obj) { unsigned long flags; bool work; + struct debug_percpu_free *percpu_pool; - raw_spin_lock_irqsave(&pool_lock, flags); + local_irq_save(flags); + /* + * Try to free it into the percpu pool first. + */ + percpu_pool = this_cpu_ptr(&percpu_obj_pool); + if (obj_cache && 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 false; + } + + raw_spin_lock(&pool_lock); work = (obj_pool_free > debug_objects_pool_size) && obj_cache; obj_pool_used--; @@ -259,7 +311,8 @@ static bool __free_object(struct debug_obj *obj) obj_pool_free++; hlist_add_head(&obj->node, &obj_pool); } - raw_spin_unlock_irqrestore(&pool_lock, flags); + raw_spin_unlock(&pool_lock); + local_irq_restore(flags); return work; } @@ -318,6 +371,15 @@ static void debug_print_object(struct debug_obj *obj, char *msg) 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; @@ -368,6 +430,55 @@ 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, + 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: + */ + if (!IS_ENABLED(CONFIG_PREEMPT_RT) || preemptible()) + fill_pool(); +} + static void __debug_object_init(void *addr, struct debug_obj_descr *descr, int onstack) { @@ -376,25 +487,17 @@ __debug_object_init(void *addr, struct debug_obj_descr *descr, int onstack) struct debug_obj *obj; unsigned long flags; -#ifdef CONFIG_PREEMPT_RT_FULL - if (preempt_count() == 0 && !irqs_disabled()) -#endif - 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) { @@ -405,15 +508,16 @@ __debug_object_init(void *addr, struct debug_obj_descr *descr, int onstack) break; case ODEBUG_STATE_ACTIVE: - debug_print_object(obj, "init"); state = obj->state; raw_spin_unlock_irqrestore(&db->lock, flags); + debug_print_object(obj, "init"); debug_object_fixup(descr->fixup_init, addr, state); return; case ODEBUG_STATE_DESTROYED: + raw_spin_unlock_irqrestore(&db->lock, flags); debug_print_object(obj, "init"); - break; + return; default: break; } @@ -458,24 +562,26 @@ EXPORT_SYMBOL_GPL(debug_object_init_on_stack); */ int debug_object_activate(void *addr, struct debug_obj_descr *descr) { + struct debug_obj o = { .object = addr, .state = ODEBUG_STATE_NOTAVAILABLE, .descr = descr }; enum debug_obj_state state; 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 (likely(!IS_ERR_OR_NULL(obj))) { + bool print_object = false; + switch (obj->state) { case ODEBUG_STATE_INIT: case ODEBUG_STATE_INACTIVE: @@ -484,14 +590,14 @@ int debug_object_activate(void *addr, struct debug_obj_descr *descr) break; case ODEBUG_STATE_ACTIVE: - debug_print_object(obj, "activate"); state = obj->state; raw_spin_unlock_irqrestore(&db->lock, flags); + debug_print_object(obj, "activate"); ret = debug_object_fixup(descr->fixup_activate, addr, state); return ret ? 0 : -EINVAL; case ODEBUG_STATE_DESTROYED: - debug_print_object(obj, "activate"); + print_object = true; ret = -EINVAL; break; default: @@ -499,28 +605,23 @@ int debug_object_activate(void *addr, struct debug_obj_descr *descr) break; } raw_spin_unlock_irqrestore(&db->lock, flags); + if (print_object) + debug_print_object(obj, "activate"); 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; + + /* If NULL the allocation has hit OOM */ + if (!obj) { + debug_objects_oom(); + return 0; } - return 0; + + /* Object is neither static nor tracked. It's not initialized */ + debug_print_object(&o, "activate"); + ret = debug_object_fixup(descr->fixup_activate, addr, ODEBUG_STATE_NOTAVAILABLE); + return ret ? 0 : -EINVAL; } EXPORT_SYMBOL_GPL(debug_object_activate); @@ -534,6 +635,7 @@ void debug_object_deactivate(void *addr, struct debug_obj_descr *descr) struct debug_bucket *db; struct debug_obj *obj; unsigned long flags; + bool print_object = false; if (!debug_objects_enabled) return; @@ -551,24 +653,27 @@ void debug_object_deactivate(void *addr, struct debug_obj_descr *descr) if (!obj->astate) obj->state = ODEBUG_STATE_INACTIVE; else - debug_print_object(obj, "deactivate"); + print_object = true; break; case ODEBUG_STATE_DESTROYED: - debug_print_object(obj, "deactivate"); + print_object = true; break; default: break; } - } else { + } + + raw_spin_unlock_irqrestore(&db->lock, flags); + if (!obj) { struct debug_obj o = { .object = addr, .state = ODEBUG_STATE_NOTAVAILABLE, .descr = descr }; debug_print_object(&o, "deactivate"); + } else if (print_object) { + debug_print_object(obj, "deactivate"); } - - raw_spin_unlock_irqrestore(&db->lock, flags); } EXPORT_SYMBOL_GPL(debug_object_deactivate); @@ -583,6 +688,7 @@ void debug_object_destroy(void *addr, struct debug_obj_descr *descr) struct debug_bucket *db; struct debug_obj *obj; unsigned long flags; + bool print_object = false; if (!debug_objects_enabled) return; @@ -602,20 +708,22 @@ void debug_object_destroy(void *addr, struct debug_obj_descr *descr) obj->state = ODEBUG_STATE_DESTROYED; break; case ODEBUG_STATE_ACTIVE: - debug_print_object(obj, "destroy"); state = obj->state; raw_spin_unlock_irqrestore(&db->lock, flags); + debug_print_object(obj, "destroy"); debug_object_fixup(descr->fixup_destroy, addr, state); return; case ODEBUG_STATE_DESTROYED: - debug_print_object(obj, "destroy"); + print_object = true; break; default: break; } out_unlock: raw_spin_unlock_irqrestore(&db->lock, flags); + if (print_object) + debug_print_object(obj, "destroy"); } EXPORT_SYMBOL_GPL(debug_object_destroy); @@ -644,9 +752,9 @@ void debug_object_free(void *addr, struct debug_obj_descr *descr) switch (obj->state) { case ODEBUG_STATE_ACTIVE: - debug_print_object(obj, "free"); state = obj->state; raw_spin_unlock_irqrestore(&db->lock, flags); + debug_print_object(obj, "free"); debug_object_fixup(descr->fixup_free, addr, state); return; default: @@ -667,6 +775,7 @@ EXPORT_SYMBOL_GPL(debug_object_free); */ void debug_object_assert_init(void *addr, 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; @@ -674,34 +783,25 @@ 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); @@ -719,6 +819,7 @@ debug_object_active_state(void *addr, struct debug_obj_descr *descr, struct debug_bucket *db; struct debug_obj *obj; unsigned long flags; + bool print_object = false; if (!debug_objects_enabled) return; @@ -734,22 +835,25 @@ debug_object_active_state(void *addr, struct debug_obj_descr *descr, if (obj->astate == expect) obj->astate = next; else - debug_print_object(obj, "active_state"); + print_object = true; break; default: - debug_print_object(obj, "active_state"); + print_object = true; break; } - } else { + } + + raw_spin_unlock_irqrestore(&db->lock, flags); + if (!obj) { struct debug_obj o = { .object = addr, .state = ODEBUG_STATE_NOTAVAILABLE, .descr = descr }; debug_print_object(&o, "active_state"); + } else if (print_object) { + debug_print_object(obj, "active_state"); } - - raw_spin_unlock_irqrestore(&db->lock, flags); } EXPORT_SYMBOL_GPL(debug_object_active_state); @@ -785,10 +889,10 @@ repeat: switch (obj->state) { case ODEBUG_STATE_ACTIVE: - debug_print_object(obj, "free"); descr = obj->descr; state = obj->state; raw_spin_unlock_irqrestore(&db->lock, flags); + debug_print_object(obj, "free"); debug_object_fixup(descr->fixup_free, (void *) oaddr, state); goto repeat; @@ -825,13 +929,19 @@ 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", 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, "objs_allocated:%d\n", debug_objects_allocated); @@ -1180,9 +1290,20 @@ free: */ void __init debug_objects_mem_init(void) { + int cpu; + 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, @@ -1194,11 +1315,4 @@ void __init debug_objects_mem_init(void) pr_warn("out of memory.\n"); } else debug_objects_selftest(); - - /* - * 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; } |