Adding upstream version 4.19.249.upstream/4.19.249upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1201 insertions, 0 deletions

diff --git a/lib/debugobjects.c b/lib/debugobjects.c
new file mode 100644
index 000000000..14afeeb7d
--- /dev/null
+++ b/lib/debugobjects.c
@@ -0,0 +1,1201 @@
+/*
+ * 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
+
+#include <linux/debugobjects.h>
+#include <linux/interrupt.h>
+#include <linux/sched.h>
+#include <linux/sched/task_stack.h>
+#include <linux/seq_file.h>
+#include <linux/debugfs.h>
+#include <linux/slab.h>
+#include <linux/hash.h>
+#include <linux/kmemleak.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_CHUNK_SHIFT	PAGE_SHIFT
+#define ODEBUG_CHUNK_SIZE	(1 << ODEBUG_CHUNK_SHIFT)
+#define ODEBUG_CHUNK_MASK	(~(ODEBUG_CHUNK_SIZE - 1))
+
+struct debug_bucket {
+	struct hlist_head	list;
+	raw_spinlock_t		lock;
+};
+
+static struct debug_bucket	obj_hash[ODEBUG_HASH_SIZE];
+
+static struct debug_obj		obj_static_pool[ODEBUG_POOL_SIZE] __initdata;
+
+static DEFINE_RAW_SPINLOCK(pool_lock);
+
+static HLIST_HEAD(obj_pool);
+static HLIST_HEAD(obj_to_free);
+
+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;
+static int			debug_objects_fixups __read_mostly;
+static int			debug_objects_warnings __read_mostly;
+static int			debug_objects_enabled __read_mostly
+				= CONFIG_DEBUG_OBJECTS_ENABLE_DEFAULT;
+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;
+
+/*
+ * Track numbers of kmem_cache_alloc()/free() calls done.
+ */
+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 int __init enable_object_debug(char *str)
+{
+	debug_objects_enabled = 1;
+	return 0;
+}
+
+static int __init disable_object_debug(char *str)
+{
+	debug_objects_enabled = 0;
+	return 0;
+}
+
+early_param("debug_objects", enable_object_debug);
+early_param("no_debug_objects", disable_object_debug);
+
+static const char *obj_states[ODEBUG_STATE_MAX] = {
+	[ODEBUG_STATE_NONE]		= "none",
+	[ODEBUG_STATE_INIT]		= "initialized",
+	[ODEBUG_STATE_INACTIVE]		= "inactive",
+	[ODEBUG_STATE_ACTIVE]		= "active",
+	[ODEBUG_STATE_DESTROYED]	= "destroyed",
+	[ODEBUG_STATE_NOTAVAILABLE]	= "not available",
+};
+
+static void fill_pool(void)
+{
+	gfp_t gfp = GFP_ATOMIC | __GFP_NORETRY | __GFP_NOWARN;
+	struct debug_obj *new, *obj;
+	unsigned long flags;
+
+	if (likely(obj_pool_free >= debug_objects_pool_min_level))
+		return;
+
+	/*
+	 * Reuse objs from the global free list; they will be reinitialized
+	 * when allocating.
+	 */
+	while (obj_nr_tofree && (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) {
+			obj = hlist_entry(obj_to_free.first, typeof(*obj), node);
+			hlist_del(&obj->node);
+			obj_nr_tofree--;
+			hlist_add_head(&obj->node, &obj_pool);
+			obj_pool_free++;
+		}
+		raw_spin_unlock_irqrestore(&pool_lock, flags);
+	}
+
+	if (unlikely(!obj_cache))
+		return;
+
+	while (obj_pool_free < debug_objects_pool_min_level) {
+
+		new = kmem_cache_zalloc(obj_cache, gfp);
+		if (!new)
+			return;
+
+		raw_spin_lock_irqsave(&pool_lock, flags);
+		hlist_add_head(&new->node, &obj_pool);
+		debug_objects_allocated++;
+		obj_pool_free++;
+		raw_spin_unlock_irqrestore(&pool_lock, flags);
+	}
+}
+
+/*
+ * Lookup an object in the hash bucket.
+ */
+static struct debug_obj *lookup_object(void *addr, struct debug_bucket *b)
+{
+	struct debug_obj *obj;
+	int cnt = 0;
+
+	hlist_for_each_entry(obj, &b->list, node) {
+		cnt++;
+		if (obj->object == addr)
+			return obj;
+	}
+	if (cnt > debug_objects_maxchain)
+		debug_objects_maxchain = cnt;
+
+	return NULL;
+}
+
+/*
+ * Allocate a new object. If the pool is empty, switch off the debugger.
+ * Must be called with interrupts disabled.
+ */
+static struct debug_obj *
+alloc_object(void *addr, struct debug_bucket *b, struct debug_obj_descr *descr)
+{
+	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;
+		hlist_del(&obj->node);
+
+		hlist_add_head(&obj->node, &b->list);
+
+		obj_pool_used++;
+		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);
+
+	return obj;
+}
+
+/*
+ * workqueue function to free objects.
+ *
+ * To reduce contention on the global pool_lock, the actual freeing of
+ * debug objects will be delayed if the pool_lock is busy.
+ */
+static void free_obj_work(struct work_struct *work)
+{
+	struct hlist_node *tmp;
+	struct debug_obj *obj;
+	unsigned long flags;
+	HLIST_HEAD(tofree);
+
+	if (!raw_spin_trylock_irqsave(&pool_lock, flags))
+		return;
+
+	/*
+	 * 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
+	 */
+	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--;
+	}
+
+	/*
+	 * 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
+	 * memory outside the pool_lock held region.
+	 */
+	if (obj_nr_tofree) {
+		hlist_move_list(&obj_to_free, &tofree);
+		debug_objects_freed += obj_nr_tofree;
+		obj_nr_tofree = 0;
+	}
+	raw_spin_unlock_irqrestore(&pool_lock, flags);
+
+	hlist_for_each_entry_safe(obj, tmp, &tofree, node) {
+		hlist_del(&obj->node);
+		kmem_cache_free(obj_cache, obj);
+	}
+}
+
+static bool __free_object(struct debug_obj *obj)
+{
+	unsigned long flags;
+	bool work;
+
+	raw_spin_lock_irqsave(&pool_lock, flags);
+	work = (obj_pool_free > debug_objects_pool_size) && obj_cache;
+	obj_pool_used--;
+
+	if (work) {
+		obj_nr_tofree++;
+		hlist_add_head(&obj->node, &obj_to_free);
+	} else {
+		obj_pool_free++;
+		hlist_add_head(&obj->node, &obj_pool);
+	}
+	raw_spin_unlock_irqrestore(&pool_lock, flags);
+	return work;
+}
+
+/*
+ * Put the object back into the pool and schedule work to free objects
+ * if necessary.
+ */
+static void free_object(struct debug_obj *obj)
+{
+	if (__free_object(obj))
+		schedule_work(&debug_obj_work);
+}
+
+/*
+ * We run out of memory. That means we probably have tons of objects
+ * allocated.
+ */
+static void debug_objects_oom(void)
+{
+	struct debug_bucket *db = obj_hash;
+	struct hlist_node *tmp;
+	HLIST_HEAD(freelist);
+	struct debug_obj *obj;
+	unsigned long flags;
+	int i;
+
+	pr_warn("Out of memory. ODEBUG disabled\n");
+
+	for (i = 0; i < ODEBUG_HASH_SIZE; i++, db++) {
+		raw_spin_lock_irqsave(&db->lock, flags);
+		hlist_move_list(&db->list, &freelist);
+		raw_spin_unlock_irqrestore(&db->lock, flags);
+
+		/* Now free them */
+		hlist_for_each_entry_safe(obj, tmp, &freelist, node) {
+			hlist_del(&obj->node);
+			free_object(obj);
+		}
+	}
+}
+
+/*
+ * We use the pfn of the address for the hash. That way we can check
+ * for freed objects simply by checking the affected bucket.
+ */
+static struct debug_bucket *get_bucket(unsigned long addr)
+{
+	unsigned long hash;
+
+	hash = hash_long((addr >> ODEBUG_CHUNK_SHIFT), ODEBUG_HASH_BITS);
+	return &obj_hash[hash];
+}
+
+static void debug_print_object(struct debug_obj *obj, char *msg)
+{
+	struct debug_obj_descr *descr = obj->descr;
+	static int limit;
+
+	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",
+			msg, obj_states[obj->state], obj->astate,
+			descr->name, hint);
+	}
+	debug_objects_warnings++;
+}
+
+/*
+ * Try to repair the damage, so we have a better chance to get useful
+ * debug output.
+ */
+static bool
+debug_object_fixup(bool (*fixup)(void *addr, enum debug_obj_state state),
+		   void * addr, enum debug_obj_state state)
+{
+	if (fixup && fixup(addr, state)) {
+		debug_objects_fixups++;
+		return true;
+	}
+	return false;
+}
+
+static void debug_object_is_on_stack(void *addr, int onstack)
+{
+	int is_on_stack;
+	static int limit;
+
+	if (limit > 4)
+		return;
+
+	is_on_stack = object_is_on_stack(addr);
+	if (is_on_stack == onstack)
+		return;
+
+	limit++;
+	if (is_on_stack)
+		pr_warn("object %p is on stack %p, but NOT annotated.\n", addr,
+			 task_stack_page(current));
+	else
+		pr_warn("object %p is NOT on stack %p, but annotated.\n", addr,
+			 task_stack_page(current));
+
+	WARN_ON(1);
+}
+
+static void
+__debug_object_init(void *addr, struct debug_obj_descr *descr, int onstack)
+{
+	enum debug_obj_state state;
+	struct debug_bucket *db;
+	struct debug_obj *obj;
+	unsigned long flags;
+
+	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);
+	}
+
+	switch (obj->state) {
+	case ODEBUG_STATE_NONE:
+	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;
+	}
+
+	raw_spin_unlock_irqrestore(&db->lock, flags);
+}
+
+/**
+ * debug_object_init - debug checks when an object is initialized
+ * @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)
+{
+	if (!debug_objects_enabled)
+		return;
+
+	__debug_object_init(addr, descr, 0);
+}
+EXPORT_SYMBOL_GPL(debug_object_init);
+
+/**
+ * debug_object_init_on_stack - debug checks when an object on stack is
+ *				initialized
+ * @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)
+{
+	if (!debug_objects_enabled)
+		return;
+
+	__debug_object_init(addr, descr, 1);
+}
+EXPORT_SYMBOL_GPL(debug_object_init_on_stack);
+
+/**
+ * debug_object_activate - debug checks when an object is activated
+ * @addr:	address of the object
+ * @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)
+{
+	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;
+
+	db = get_bucket((unsigned long) addr);
+
+	raw_spin_lock_irqsave(&db->lock, flags);
+
+	obj = lookup_object(addr, db);
+	if (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;
+			break;
+		default:
+			ret = 0;
+			break;
+		}
+		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;
+	}
+	return 0;
+}
+EXPORT_SYMBOL_GPL(debug_object_activate);
+
+/**
+ * debug_object_deactivate - debug checks when an object is deactivated
+ * @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)
+{
+	struct debug_bucket *db;
+	struct debug_obj *obj;
+	unsigned long flags;
+
+	if (!debug_objects_enabled)
+		return;
+
+	db = get_bucket((unsigned long) addr);
+
+	raw_spin_lock_irqsave(&db->lock, flags);
+
+	obj = lookup_object(addr, db);
+	if (obj) {
+		switch (obj->state) {
+		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;
+		default:
+			break;
+		}
+	} else {
+		struct debug_obj o = { .object = addr,
+				       .state = ODEBUG_STATE_NOTAVAILABLE,
+				       .descr = descr };
+
+		debug_print_object(&o, "deactivate");
+	}
+
+	raw_spin_unlock_irqrestore(&db->lock, flags);
+}
+EXPORT_SYMBOL_GPL(debug_object_deactivate);
+
+/**
+ * debug_object_destroy - debug checks when an object is destroyed
+ * @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)
+{
+	enum debug_obj_state state;
+	struct debug_bucket *db;
+	struct debug_obj *obj;
+	unsigned long flags;
+
+	if (!debug_objects_enabled)
+		return;
+
+	db = get_bucket((unsigned long) addr);
+
+	raw_spin_lock_irqsave(&db->lock, flags);
+
+	obj = lookup_object(addr, db);
+	if (!obj)
+		goto out_unlock;
+
+	switch (obj->state) {
+	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;
+		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:
+	raw_spin_unlock_irqrestore(&db->lock, flags);
+}
+EXPORT_SYMBOL_GPL(debug_object_destroy);
+
+/**
+ * debug_object_free - debug checks when an object is freed
+ * @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)
+{
+	enum debug_obj_state state;
+	struct debug_bucket *db;
+	struct debug_obj *obj;
+	unsigned long flags;
+
+	if (!debug_objects_enabled)
+		return;
+
+	db = get_bucket((unsigned long) addr);
+
+	raw_spin_lock_irqsave(&db->lock, flags);
+
+	obj = lookup_object(addr, db);
+	if (!obj)
+		goto out_unlock;
+
+	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;
+	default:
+		hlist_del(&obj->node);
+		raw_spin_unlock_irqrestore(&db->lock, flags);
+		free_object(obj);
+		return;
+	}
+out_unlock:
+	raw_spin_unlock_irqrestore(&db->lock, flags);
+}
+EXPORT_SYMBOL_GPL(debug_object_free);
+
+/**
+ * debug_object_assert_init - debug checks when object should be init-ed
+ * @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)
+{
+	struct debug_bucket *db;
+	struct debug_obj *obj;
+	unsigned long flags;
+
+	if (!debug_objects_enabled)
+		return;
+
+	db = get_bucket((unsigned long) addr);
+
+	raw_spin_lock_irqsave(&db->lock, flags);
+
+	obj = lookup_object(addr, db);
+	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);
+		}
+		return;
+	}
+
+	raw_spin_unlock_irqrestore(&db->lock, flags);
+}
+EXPORT_SYMBOL_GPL(debug_object_assert_init);
+
+/**
+ * debug_object_active_state - debug checks object usage state machine
+ * @addr:	address of the object
+ * @descr:	pointer to an object specific debug description structure
+ * @expect:	expected state
+ * @next:	state to move to if expected state is found
+ */
+void
+debug_object_active_state(void *addr, struct debug_obj_descr *descr,
+			  unsigned int expect, unsigned int next)
+{
+	struct debug_bucket *db;
+	struct debug_obj *obj;
+	unsigned long flags;
+
+	if (!debug_objects_enabled)
+		return;
+
+	db = get_bucket((unsigned long) addr);
+
+	raw_spin_lock_irqsave(&db->lock, flags);
+
+	obj = lookup_object(addr, db);
+	if (obj) {
+		switch (obj->state) {
+		case ODEBUG_STATE_ACTIVE:
+			if (obj->astate == expect)
+				obj->astate = next;
+			else
+				debug_print_object(obj, "active_state");
+			break;
+
+		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");
+	}
+
+	raw_spin_unlock_irqrestore(&db->lock, flags);
+}
+EXPORT_SYMBOL_GPL(debug_object_active_state);
+
+#ifdef CONFIG_DEBUG_OBJECTS_FREE
+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;
+	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;
+	paddr = saddr & ODEBUG_CHUNK_MASK;
+	chunks = ((eaddr - paddr) + (ODEBUG_CHUNK_SIZE - 1));
+	chunks >>= ODEBUG_CHUNK_SHIFT;
+
+	for (;chunks > 0; chunks--, paddr += ODEBUG_CHUNK_SIZE) {
+		db = get_bucket(paddr);
+
+repeat:
+		cnt = 0;
+		raw_spin_lock_irqsave(&db->lock, flags);
+		hlist_for_each_entry_safe(obj, tmp, &db->list, node) {
+			cnt++;
+			oaddr = (unsigned long) obj->object;
+			if (oaddr < saddr || oaddr >= eaddr)
+				continue;
+
+			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_object_fixup(descr->fixup_free,
+						   (void *) oaddr, state);
+				goto repeat;
+			default:
+				hlist_del(&obj->node);
+				work |= __free_object(obj);
+				break;
+			}
+		}
+		raw_spin_unlock_irqrestore(&db->lock, flags);
+
+		if (cnt > debug_objects_maxchain)
+			debug_objects_maxchain = cnt;
+
+		objs_checked += cnt;
+	}
+
+	if (objs_checked > debug_objects_maxchecked)
+		debug_objects_maxchecked = objs_checked;
+
+	/* Schedule work to actually kmem_cache_free() objects */
+	if (work)
+		schedule_work(&debug_obj_work);
+}
+
+void debug_check_no_obj_freed(const void *address, unsigned long size)
+{
+	if (debug_objects_enabled)
+		__debug_check_no_obj_freed(address, size);
+}
+#endif
+
+#ifdef CONFIG_DEBUG_FS
+
+static int debug_stats_show(struct seq_file *m, void *v)
+{
+	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_min_free :%d\n", obj_pool_min_free);
+	seq_printf(m, "pool_used     :%d\n", obj_pool_used);
+	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);
+	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,
+};
+
+static int __init debug_objects_init_debugfs(void)
+{
+	struct dentry *dbgdir, *dbgstats;
+
+	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;
+
+	return 0;
+
+err:
+	debugfs_remove(dbgdir);
+
+	return -ENOMEM;
+}
+__initcall(debug_objects_init_debugfs);
+
+#else
+static inline void debug_objects_init_debugfs(void) { }
+#endif
+
+#ifdef CONFIG_DEBUG_OBJECTS_SELFTEST
+
+/* Random data structure for the self test */
+struct self_test {
+	unsigned long	dummy1[6];
+	int		static_init;
+	unsigned long	dummy2[3];
+};
+
+static __initdata struct debug_obj_descr descr_type_test;
+
+static bool __init is_static_object(void *addr)
+{
+	struct self_test *obj = addr;
+
+	return obj->static_init;
+}
+
+/*
+ * fixup_init is called when:
+ * - an active object is initialized
+ */
+static bool __init fixup_init(void *addr, enum debug_obj_state state)
+{
+	struct self_test *obj = addr;
+
+	switch (state) {
+	case ODEBUG_STATE_ACTIVE:
+		debug_object_deactivate(obj, &descr_type_test);
+		debug_object_init(obj, &descr_type_test);
+		return true;
+	default:
+		return false;
+	}
+}
+
+/*
+ * fixup_activate is called when:
+ * - an active object is activated
+ * - an unknown non-static object is activated
+ */
+static bool __init fixup_activate(void *addr, enum debug_obj_state state)
+{
+	struct self_test *obj = addr;
+
+	switch (state) {
+	case ODEBUG_STATE_NOTAVAILABLE:
+		return true;
+	case ODEBUG_STATE_ACTIVE:
+		debug_object_deactivate(obj, &descr_type_test);
+		debug_object_activate(obj, &descr_type_test);
+		return true;
+
+	default:
+		return false;
+	}
+}
+
+/*
+ * fixup_destroy is called when:
+ * - an active object is destroyed
+ */
+static bool __init fixup_destroy(void *addr, enum debug_obj_state state)
+{
+	struct self_test *obj = addr;
+
+	switch (state) {
+	case ODEBUG_STATE_ACTIVE:
+		debug_object_deactivate(obj, &descr_type_test);
+		debug_object_destroy(obj, &descr_type_test);
+		return true;
+	default:
+		return false;
+	}
+}
+
+/*
+ * fixup_free is called when:
+ * - an active object is freed
+ */
+static bool __init fixup_free(void *addr, enum debug_obj_state state)
+{
+	struct self_test *obj = addr;
+
+	switch (state) {
+	case ODEBUG_STATE_ACTIVE:
+		debug_object_deactivate(obj, &descr_type_test);
+		debug_object_free(obj, &descr_type_test);
+		return true;
+	default:
+		return false;
+	}
+}
+
+static int __init
+check_results(void *addr, enum debug_obj_state state, int fixups, int warnings)
+{
+	struct debug_bucket *db;
+	struct debug_obj *obj;
+	unsigned long flags;
+	int res = -EINVAL;
+
+	db = get_bucket((unsigned long) addr);
+
+	raw_spin_lock_irqsave(&db->lock, flags);
+
+	obj = lookup_object(addr, db);
+	if (!obj && state != ODEBUG_STATE_NONE) {
+		WARN(1, KERN_ERR "ODEBUG: selftest object not found\n");
+		goto out;
+	}
+	if (obj && obj->state != state) {
+		WARN(1, KERN_ERR "ODEBUG: selftest wrong state: %d != %d\n",
+		       obj->state, state);
+		goto out;
+	}
+	if (fixups != debug_objects_fixups) {
+		WARN(1, KERN_ERR "ODEBUG: selftest fixups failed %d != %d\n",
+		       fixups, debug_objects_fixups);
+		goto out;
+	}
+	if (warnings != debug_objects_warnings) {
+		WARN(1, KERN_ERR "ODEBUG: selftest warnings failed %d != %d\n",
+		       warnings, debug_objects_warnings);
+		goto out;
+	}
+	res = 0;
+out:
+	raw_spin_unlock_irqrestore(&db->lock, flags);
+	if (res)
+		debug_objects_enabled = 0;
+	return res;
+}
+
+static __initdata struct debug_obj_descr descr_type_test = {
+	.name			= "selftest",
+	.is_static_object	= is_static_object,
+	.fixup_init		= fixup_init,
+	.fixup_activate		= fixup_activate,
+	.fixup_destroy		= fixup_destroy,
+	.fixup_free		= fixup_free,
+};
+
+static __initdata struct self_test obj = { .static_init = 0 };
+
+static void __init debug_objects_selftest(void)
+{
+	int fixups, oldfixups, warnings, oldwarnings;
+	unsigned long flags;
+
+	local_irq_save(flags);
+
+	fixups = oldfixups = debug_objects_fixups;
+	warnings = oldwarnings = debug_objects_warnings;
+	descr_test = &descr_type_test;
+
+	debug_object_init(&obj, &descr_type_test);
+	if (check_results(&obj, ODEBUG_STATE_INIT, fixups, warnings))
+		goto out;
+	debug_object_activate(&obj, &descr_type_test);
+	if (check_results(&obj, ODEBUG_STATE_ACTIVE, fixups, warnings))
+		goto out;
+	debug_object_activate(&obj, &descr_type_test);
+	if (check_results(&obj, ODEBUG_STATE_ACTIVE, ++fixups, ++warnings))
+		goto out;
+	debug_object_deactivate(&obj, &descr_type_test);
+	if (check_results(&obj, ODEBUG_STATE_INACTIVE, fixups, warnings))
+		goto out;
+	debug_object_destroy(&obj, &descr_type_test);
+	if (check_results(&obj, ODEBUG_STATE_DESTROYED, fixups, warnings))
+		goto out;
+	debug_object_init(&obj, &descr_type_test);
+	if (check_results(&obj, ODEBUG_STATE_DESTROYED, fixups, ++warnings))
+		goto out;
+	debug_object_activate(&obj, &descr_type_test);
+	if (check_results(&obj, ODEBUG_STATE_DESTROYED, fixups, ++warnings))
+		goto out;
+	debug_object_deactivate(&obj, &descr_type_test);
+	if (check_results(&obj, ODEBUG_STATE_DESTROYED, fixups, ++warnings))
+		goto out;
+	debug_object_free(&obj, &descr_type_test);
+	if (check_results(&obj, ODEBUG_STATE_NONE, fixups, warnings))
+		goto out;
+
+	obj.static_init = 1;
+	debug_object_activate(&obj, &descr_type_test);
+	if (check_results(&obj, ODEBUG_STATE_ACTIVE, fixups, warnings))
+		goto out;
+	debug_object_init(&obj, &descr_type_test);
+	if (check_results(&obj, ODEBUG_STATE_INIT, ++fixups, ++warnings))
+		goto out;
+	debug_object_free(&obj, &descr_type_test);
+	if (check_results(&obj, ODEBUG_STATE_NONE, fixups, warnings))
+		goto out;
+
+#ifdef CONFIG_DEBUG_OBJECTS_FREE
+	debug_object_init(&obj, &descr_type_test);
+	if (check_results(&obj, ODEBUG_STATE_INIT, fixups, warnings))
+		goto out;
+	debug_object_activate(&obj, &descr_type_test);
+	if (check_results(&obj, ODEBUG_STATE_ACTIVE, fixups, warnings))
+		goto out;
+	__debug_check_no_obj_freed(&obj, sizeof(obj));
+	if (check_results(&obj, ODEBUG_STATE_NONE, ++fixups, ++warnings))
+		goto out;
+#endif
+	pr_info("selftest passed\n");
+
+out:
+	debug_objects_fixups = oldfixups;
+	debug_objects_warnings = oldwarnings;
+	descr_test = NULL;
+
+	local_irq_restore(flags);
+}
+#else
+static inline void debug_objects_selftest(void) { }
+#endif
+
+/*
+ * Called during early boot to initialize the hash buckets and link
+ * the static object pool objects into the poll list. After this call
+ * the object tracker is fully operational.
+ */
+void __init debug_objects_early_init(void)
+{
+	int i;
+
+	for (i = 0; i < ODEBUG_HASH_SIZE; i++)
+		raw_spin_lock_init(&obj_hash[i].lock);
+
+	for (i = 0; i < ODEBUG_POOL_SIZE; i++)
+		hlist_add_head(&obj_static_pool[i].node, &obj_pool);
+}
+
+/*
+ * Convert the statically allocated objects to dynamic ones:
+ */
+static int __init debug_objects_replace_static_objects(void)
+{
+	struct debug_bucket *db = obj_hash;
+	struct hlist_node *tmp;
+	struct debug_obj *obj, *new;
+	HLIST_HEAD(objects);
+	int i, cnt = 0;
+
+	for (i = 0; i < ODEBUG_POOL_SIZE; i++) {
+		obj = kmem_cache_zalloc(obj_cache, GFP_KERNEL);
+		if (!obj)
+			goto free;
+		hlist_add_head(&obj->node, &objects);
+	}
+
+	/*
+	 * When debug_objects_mem_init() is called we know that only
+	 * one CPU is up, so disabling interrupts is enough
+	 * protection. This avoids the lockdep hell of lock ordering.
+	 */
+	local_irq_disable();
+
+	/* Remove the statically allocated objects from the pool */
+	hlist_for_each_entry_safe(obj, tmp, &obj_pool, node)
+		hlist_del(&obj->node);
+	/* Move the allocated objects to the pool */
+	hlist_move_list(&objects, &obj_pool);
+
+	/* Replace the active object references */
+	for (i = 0; i < ODEBUG_HASH_SIZE; i++, db++) {
+		hlist_move_list(&db->list, &objects);
+
+		hlist_for_each_entry(obj, &objects, node) {
+			new = hlist_entry(obj_pool.first, typeof(*obj), node);
+			hlist_del(&new->node);
+			/* copy object data */
+			*new = *obj;
+			hlist_add_head(&new->node, &db->list);
+			cnt++;
+		}
+	}
+	local_irq_enable();
+
+	pr_debug("%d of %d active objects replaced\n",
+		 cnt, obj_pool_used);
+	return 0;
+free:
+	hlist_for_each_entry_safe(obj, tmp, &objects, node) {
+		hlist_del(&obj->node);
+		kmem_cache_free(obj_cache, obj);
+	}
+	return -ENOMEM;
+}
+
+/*
+ * Called after the kmem_caches are functional to setup a dedicated
+ * cache pool, which has the SLAB_DEBUG_OBJECTS flag set. This flag
+ * prevents that the debug code is called on kmem_cache_free() for the
+ * debug tracker objects to avoid recursive calls.
+ */
+void __init debug_objects_mem_init(void)
+{
+	if (!debug_objects_enabled)
+		return;
+
+	obj_cache = kmem_cache_create("debug_objects_cache",
+				      sizeof (struct debug_obj), 0,
+				      SLAB_DEBUG_OBJECTS | SLAB_NOLEAKTRACE,
+				      NULL);
+
+	if (!obj_cache || debug_objects_replace_static_objects()) {
+		debug_objects_enabled = 0;
+		kmem_cache_destroy(obj_cache);
+		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;
+}