driver core: class: properly reference count class_dev_iter()

When class_dev_iter is initialized, the reference count for the subsys private structure is incremented, but never decremented, causing a memory leak over time. To resolve this, save off a pointer to the internal structure into the class_dev_iter structure and then when the iterator is finished, drop the reference count.

Greg Kroah-Hartman committed 3 years ago

Commit ddaf0981 parent 1e94be72 files · +3 −0Browse files

Unified · Split

2 files

drivers/base/class.c +2 −0
include/linux/device/class.h +1 −0

drivers/base/class.c+2−0

@@ -320,6 +320,7 @@ void class_dev_iter_init(struct class_dev_iter iter, const struct class class, · 319 unmodified lines
320	320	start_knode = &start->p->knode_class;
321	321	klist_iter_init_node(&sp->klist_devices, &iter->ki, start_knode);
322	322	iter->type = type;
	323	+ iter->sp = sp;
323	324	}
324	325	EXPORT_SYMBOL_GPL(class_dev_iter_init);
325	326
@@ -361,6 +362,7 @@ EXPORT_SYMBOL_GPL(class_dev_iter_next); · 35 unmodified lines
361	362	void class_dev_iter_exit(struct class_dev_iter *iter)
362	363	{
363	364	klist_iter_exit(&iter->ki);
	365	+ subsys_put(iter->sp);
364	366	}
365	367	EXPORT_SYMBOL_GPL(class_dev_iter_exit);
366	368

include/linux/device/class.h+1−0

@@ -74,6 +74,7 @@ struct class { · 73 unmodified lines
74	74	struct class_dev_iter {
75	75	struct klist_iter ki;
76	76	const struct device_type *type;
	77	+ struct subsys_private *sp;
77	78	};
78	79
79	80	int __must_check class_register(const struct class *class);