*/
#include <linux/debugobjects.h>
#include <linux/interrupt.h>
+#include <linux/sched.h>
#include <linux/seq_file.h>
#include <linux/debugfs.h>
#include <linux/hash.h>
static struct debug_bucket obj_hash[ODEBUG_HASH_SIZE];
-static struct debug_obj obj_static_pool[ODEBUG_POOL_SIZE];
+static struct debug_obj obj_static_pool[ODEBUG_POOL_SIZE] __initdata;
static DEFINE_SPINLOCK(pool_lock);
static int debug_objects_maxchain __read_mostly;
static int debug_objects_fixups __read_mostly;
static int debug_objects_warnings __read_mostly;
-static int debug_objects_enabled __read_mostly;
+static int debug_objects_enabled __read_mostly
+ = CONFIG_DEBUG_OBJECTS_ENABLE_DEFAULT;
+
static struct debug_obj_descr *descr_test __read_mostly;
+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",
{
gfp_t gfp = GFP_ATOMIC | __GFP_NORETRY | __GFP_NOWARN;
struct debug_obj *new;
+ unsigned long flags;
if (likely(obj_pool_free >= ODEBUG_POOL_MIN_LEVEL))
return obj_pool_free;
if (!new)
return obj_pool_free;
- spin_lock(&pool_lock);
+ spin_lock_irqsave(&pool_lock, flags);
hlist_add_head(&new->node, &obj_pool);
obj_pool_free++;
- spin_unlock(&pool_lock);
+ spin_unlock_irqrestore(&pool_lock, flags);
}
return obj_pool_free;
}
}
/*
- * Allocate a new object. If the pool is empty and no refill possible,
- * switch off the debugger.
+ * 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;
- int retry = 0;
-repeat:
spin_lock(&pool_lock);
if (obj_pool.first) {
obj = hlist_entry(obj_pool.first, typeof(*obj), node);
}
spin_unlock(&pool_lock);
- if (fill_pool() && !obj && !retry++)
- goto repeat;
-
return obj;
}
/*
- * Put the object back into the pool or give it back to kmem_cache:
+ * workqueue function to free objects.
*/
-static void free_object(struct debug_obj *obj)
+static void free_obj_work(struct work_struct *work)
{
- unsigned long idx = (unsigned long)(obj - obj_static_pool);
+ struct debug_obj *obj;
+ unsigned long flags;
- if (obj_pool_free < ODEBUG_POOL_SIZE || idx < ODEBUG_POOL_SIZE) {
- spin_lock(&pool_lock);
- hlist_add_head(&obj->node, &obj_pool);
- obj_pool_free++;
- obj_pool_used--;
- spin_unlock(&pool_lock);
- } else {
- spin_lock(&pool_lock);
- obj_pool_used--;
- spin_unlock(&pool_lock);
+ spin_lock_irqsave(&pool_lock, flags);
+ while (obj_pool_free > ODEBUG_POOL_SIZE) {
+ obj = hlist_entry(obj_pool.first, typeof(*obj), node);
+ hlist_del(&obj->node);
+ obj_pool_free--;
+ /*
+ * We release pool_lock across kmem_cache_free() to
+ * avoid contention on pool_lock.
+ */
+ spin_unlock_irqrestore(&pool_lock, flags);
kmem_cache_free(obj_cache, obj);
+ spin_lock_irqsave(&pool_lock, flags);
}
+ spin_unlock_irqrestore(&pool_lock, flags);
+}
+
+/*
+ * Put the object back into the pool and schedule work to free objects
+ * if necessary.
+ */
+static void free_object(struct debug_obj *obj)
+{
+ unsigned long flags;
+ int sched = 0;
+
+ spin_lock_irqsave(&pool_lock, flags);
+ /*
+ * schedule work when the pool is filled and the cache is
+ * initialized:
+ */
+ if (obj_pool_free > ODEBUG_POOL_SIZE && obj_cache)
+ sched = !work_pending(&debug_obj_work);
+ hlist_add_head(&obj->node, &obj_pool);
+ obj_pool_free++;
+ obj_pool_used--;
+ spin_unlock_irqrestore(&pool_lock, flags);
+ if (sched)
+ schedule_work(&debug_obj_work);
}
/*
{
struct debug_bucket *db = obj_hash;
struct hlist_node *node, *tmp;
+ HLIST_HEAD(freelist);
struct debug_obj *obj;
unsigned long flags;
int i;
for (i = 0; i < ODEBUG_HASH_SIZE; i++, db++) {
spin_lock_irqsave(&db->lock, flags);
- hlist_for_each_entry_safe(obj, node, tmp, &db->list, node) {
+ hlist_move_list(&db->list, &freelist);
+ spin_unlock_irqrestore(&db->lock, flags);
+
+ /* Now free them */
+ hlist_for_each_entry_safe(obj, node, tmp, &freelist, node) {
hlist_del(&obj->node);
free_object(obj);
}
- spin_unlock_irqrestore(&db->lock, flags);
}
}
if (limit < 5 && obj->descr != descr_test) {
limit++;
- printk(KERN_ERR "ODEBUG: %s %s object type: %s\n", msg,
+ WARN(1, KERN_ERR "ODEBUG: %s %s object type: %s\n", msg,
obj_states[obj->state], obj->descr->name);
- WARN_ON(1);
}
debug_objects_warnings++;
}
static void debug_object_is_on_stack(void *addr, int onstack)
{
- void *stack = current->stack;
int is_on_stack;
static int limit;
if (limit > 4)
return;
- is_on_stack = (addr >= stack && addr < (stack + THREAD_SIZE));
-
+ is_on_stack = object_is_on_stack(addr);
if (is_on_stack == onstack)
return;
struct debug_obj *obj;
unsigned long flags;
+ fill_pool();
+
db = get_bucket((unsigned long) addr);
spin_lock_irqsave(&db->lock, flags);
return;
default:
hlist_del(&obj->node);
+ spin_unlock_irqrestore(&db->lock, flags);
free_object(obj);
- break;
+ return;
}
out_unlock:
spin_unlock_irqrestore(&db->lock, flags);
{
unsigned long flags, oaddr, saddr, eaddr, paddr, chunks;
struct hlist_node *node, *tmp;
+ HLIST_HEAD(freelist);
struct debug_obj_descr *descr;
enum debug_obj_state state;
struct debug_bucket *db;
goto repeat;
default:
hlist_del(&obj->node);
- free_object(obj);
+ hlist_add_head(&obj->node, &freelist);
break;
}
}
spin_unlock_irqrestore(&db->lock, flags);
+
+ /* Now free them */
+ hlist_for_each_entry_safe(obj, node, tmp, &freelist, node) {
+ hlist_del(&obj->node);
+ free_object(obj);
+ }
+
if (cnt > debug_objects_maxchain)
debug_objects_maxchain = cnt;
}
obj = lookup_object(addr, db);
if (!obj && state != ODEBUG_STATE_NONE) {
- printk(KERN_ERR "ODEBUG: selftest object not found\n");
- WARN_ON(1);
+ WARN(1, KERN_ERR "ODEBUG: selftest object not found\n");
goto out;
}
if (obj && obj->state != state) {
- printk(KERN_ERR "ODEBUG: selftest wrong state: %d != %d\n",
+ WARN(1, KERN_ERR "ODEBUG: selftest wrong state: %d != %d\n",
obj->state, state);
- WARN_ON(1);
goto out;
}
if (fixups != debug_objects_fixups) {
- printk(KERN_ERR "ODEBUG: selftest fixups failed %d != %d\n",
+ WARN(1, KERN_ERR "ODEBUG: selftest fixups failed %d != %d\n",
fixups, debug_objects_fixups);
- WARN_ON(1);
goto out;
}
if (warnings != debug_objects_warnings) {
- printk(KERN_ERR "ODEBUG: selftest warnings failed %d != %d\n",
+ WARN(1, KERN_ERR "ODEBUG: selftest warnings failed %d != %d\n",
warnings, debug_objects_warnings);
- WARN_ON(1);
goto out;
}
res = 0;
}
/*
+ * Convert the statically allocated objects to dynamic ones:
+ */
+static int debug_objects_replace_static_objects(void)
+{
+ struct debug_bucket *db = obj_hash;
+ struct hlist_node *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, node, 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, node, &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++;
+ }
+ }
+
+ printk(KERN_DEBUG "ODEBUG: %d of %d active objects replaced\n", cnt,
+ obj_pool_used);
+ local_irq_enable();
+ return 0;
+free:
+ hlist_for_each_entry_safe(obj, node, 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
sizeof (struct debug_obj), 0,
SLAB_DEBUG_OBJECTS, NULL);
- if (!obj_cache)
+ if (!obj_cache || debug_objects_replace_static_objects()) {
debug_objects_enabled = 0;
- else
+ if (obj_cache)
+ kmem_cache_destroy(obj_cache);
+ printk(KERN_WARNING "ODEBUG: out of memory.\n");
+ } else
debug_objects_selftest();
}
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff