#define MSECS_MIN_AGE 5000 /* minimum object age for reporting */
#define SECS_FIRST_SCAN 60 /* delay before the first scan */
#define SECS_SCAN_WAIT 600 /* subsequent auto scanning delay */
+#define GRAY_LIST_PASSES 25 /* maximum number of gray list scans */
#define BYTES_PER_POINTER sizeof(void *)
#define OBJECT_REPORTED (1 << 1)
/* flag set to not scan the object */
#define OBJECT_NO_SCAN (1 << 2)
+/* flag set on newly allocated objects */
+#define OBJECT_NEW (1 << 3)
/* the list of all allocated objects */
static LIST_HEAD(object_list);
enum {
KMEMLEAK_ALLOC,
KMEMLEAK_FREE,
+ KMEMLEAK_FREE_PART,
KMEMLEAK_NOT_LEAK,
KMEMLEAK_IGNORE,
KMEMLEAK_SCAN_AREA,
return object->min_count != -1 && object->count >= object->min_count;
}
+static int color_black(const struct kmemleak_object *object)
+{
+ return object->min_count == -1;
+}
+
/*
* Objects are considered unreferenced only if their color is white, they have
* not be deleted and have a minimum age to avoid false positives caused by
INIT_HLIST_HEAD(&object->area_list);
spin_lock_init(&object->lock);
atomic_set(&object->use_count, 1);
- object->flags = OBJECT_ALLOCATED;
+ object->flags = OBJECT_ALLOCATED | OBJECT_NEW;
object->pointer = ptr;
object->size = size;
object->min_count = min_count;
* Remove the metadata (struct kmemleak_object) for a memory block from the
* object_list and object_tree_root and decrement its use_count.
*/
-static void delete_object(unsigned long ptr)
+static void __delete_object(struct kmemleak_object *object)
{
unsigned long flags;
- struct kmemleak_object *object;
write_lock_irqsave(&kmemleak_lock, flags);
- object = lookup_object(ptr, 0);
- if (!object) {
-#ifdef DEBUG
- kmemleak_warn("Freeing unknown object at 0x%08lx\n",
- ptr);
-#endif
- write_unlock_irqrestore(&kmemleak_lock, flags);
- return;
- }
prio_tree_remove(&object_tree_root, &object->tree_node);
list_del_rcu(&object->object_list);
write_unlock_irqrestore(&kmemleak_lock, flags);
WARN_ON(!(object->flags & OBJECT_ALLOCATED));
- WARN_ON(atomic_read(&object->use_count) < 1);
+ WARN_ON(atomic_read(&object->use_count) < 2);
/*
* Locking here also ensures that the corresponding memory block
}
/*
+ * Look up the metadata (struct kmemleak_object) corresponding to ptr and
+ * delete it.
+ */
+static void delete_object_full(unsigned long ptr)
+{
+ struct kmemleak_object *object;
+
+ object = find_and_get_object(ptr, 0);
+ if (!object) {
+#ifdef DEBUG
+ kmemleak_warn("Freeing unknown object at 0x%08lx\n",
+ ptr);
+#endif
+ return;
+ }
+ __delete_object(object);
+ put_object(object);
+}
+
+/*
+ * Look up the metadata (struct kmemleak_object) corresponding to ptr and
+ * delete it. If the memory block is partially freed, the function may create
+ * additional metadata for the remaining parts of the block.
+ */
+static void delete_object_part(unsigned long ptr, size_t size)
+{
+ struct kmemleak_object *object;
+ unsigned long start, end;
+
+ object = find_and_get_object(ptr, 1);
+ if (!object) {
+#ifdef DEBUG
+ kmemleak_warn("Partially freeing unknown object at 0x%08lx "
+ "(size %zu)\n", ptr, size);
+#endif
+ return;
+ }
+ __delete_object(object);
+
+ /*
+ * Create one or two objects that may result from the memory block
+ * split. Note that partial freeing is only done by free_bootmem() and
+ * this happens before kmemleak_init() is called. The path below is
+ * only executed during early log recording in kmemleak_init(), so
+ * GFP_KERNEL is enough.
+ */
+ start = object->pointer;
+ end = object->pointer + object->size;
+ if (ptr > start)
+ create_object(start, ptr - start, object->min_count,
+ GFP_KERNEL);
+ if (ptr + size < end)
+ create_object(ptr + size, end - ptr - size, object->min_count,
+ GFP_KERNEL);
+
+ put_object(object);
+}
+/*
* Make a object permanently as gray-colored so that it can no longer be
* reported as a leak. This is used in general to mark a false positive.
*/
pr_debug("%s(0x%p)\n", __func__, ptr);
if (atomic_read(&kmemleak_enabled) && ptr && !IS_ERR(ptr))
- delete_object((unsigned long)ptr);
+ delete_object_full((unsigned long)ptr);
else if (atomic_read(&kmemleak_early_log))
log_early(KMEMLEAK_FREE, ptr, 0, 0, 0, 0);
}
EXPORT_SYMBOL_GPL(kmemleak_free);
/*
+ * Partial memory freeing function callback. This function is usually called
+ * from bootmem allocator when (part of) a memory block is freed.
+ */
+void kmemleak_free_part(const void *ptr, size_t size)
+{
+ pr_debug("%s(0x%p)\n", __func__, ptr);
+
+ if (atomic_read(&kmemleak_enabled) && ptr && !IS_ERR(ptr))
+ delete_object_part((unsigned long)ptr, size);
+ else if (atomic_read(&kmemleak_early_log))
+ log_early(KMEMLEAK_FREE_PART, ptr, size, 0, 0, 0);
+}
+EXPORT_SYMBOL_GPL(kmemleak_free_part);
+
+/*
* Mark an already allocated memory block as a false positive. This will cause
* the block to no longer be reported as leak and always be scanned.
*/
struct task_struct *task;
int i;
int new_leaks = 0;
+ int gray_list_pass = 0;
jiffies_last_scan = jiffies;
#endif
/* reset the reference count (whiten the object) */
object->count = 0;
+ object->flags &= ~OBJECT_NEW;
if (color_gray(object) && get_object(object))
list_add_tail(&object->gray_list, &gray_list);
* kmemleak objects cannot be freed from outside the loop because their
* use_count was increased.
*/
+repeat:
object = list_entry(gray_list.next, typeof(*object), gray_list);
while (&object->gray_list != &gray_list) {
cond_resched();
object = tmp;
}
+
+ if (scan_should_stop() || ++gray_list_pass >= GRAY_LIST_PASSES)
+ goto scan_end;
+
+ /*
+ * Check for new objects allocated during this scanning and add them
+ * to the gray list.
+ */
+ rcu_read_lock();
+ list_for_each_entry_rcu(object, &object_list, object_list) {
+ spin_lock_irqsave(&object->lock, flags);
+ if ((object->flags & OBJECT_NEW) && !color_black(object) &&
+ get_object(object)) {
+ object->flags &= ~OBJECT_NEW;
+ list_add_tail(&object->gray_list, &gray_list);
+ }
+ spin_unlock_irqrestore(&object->lock, flags);
+ }
+ rcu_read_unlock();
+
+ if (!list_empty(&gray_list))
+ goto repeat;
+
+scan_end:
WARN_ON(!list_empty(&gray_list));
/*
- * If scanning was stopped do not report any new unreferenced objects.
+ * If scanning was stopped or new objects were being allocated at a
+ * higher rate than gray list scanning, do not report any new
+ * unreferenced objects.
*/
- if (scan_should_stop())
+ if (scan_should_stop() || gray_list_pass >= GRAY_LIST_PASSES)
return;
/*
}
object = NULL;
out:
- rcu_read_unlock();
return object;
}
++(*pos);
- rcu_read_lock();
list_for_each_continue_rcu(n, &object_list) {
next_obj = list_entry(n, struct kmemleak_object, object_list);
if (get_object(next_obj))
break;
}
- rcu_read_unlock();
put_object(prev_obj);
return next_obj;
* kmemleak_seq_start may return ERR_PTR if the scan_mutex
* waiting was interrupted, so only release it if !IS_ERR.
*/
+ rcu_read_unlock();
mutex_unlock(&scan_mutex);
if (v)
put_object(v);
rcu_read_lock();
list_for_each_entry_rcu(object, &object_list, object_list)
- delete_object(object->pointer);
+ delete_object_full(object->pointer);
rcu_read_unlock();
mutex_unlock(&scan_mutex);
case KMEMLEAK_FREE:
kmemleak_free(log->ptr);
break;
+ case KMEMLEAK_FREE_PART:
+ kmemleak_free_part(log->ptr, log->size);
+ break;
case KMEMLEAK_NOT_LEAK:
kmemleak_not_leak(log->ptr);
break;
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff