extcon: Fix missing locking when [un]registering notifiers

Since extcon.c is using raw_notifiers it must protect the notifier
list itself when [un]registering notifiers to avoid the list changing while
extcon_update_state is walking the list (through raw_notifier_call_chain).

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
[cw00.choi: Apply this patch to extcon.c driver instead of old extcon-class.c]
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
This commit is contained in:
Hans de Goede 2015-03-21 17:26:24 +01:00 коммит произвёл Chanwoo Choi
Родитель b9b518f539
Коммит 66bee35f29
1 изменённых файлов: 31 добавлений и 4 удалений

Просмотреть файл

@ -445,6 +445,9 @@ int extcon_register_interest(struct extcon_specific_cable_nb *obj,
const char *extcon_name, const char *cable_name,
struct notifier_block *nb)
{
unsigned long flags;
int ret;
if (!obj || !cable_name || !nb)
return -EINVAL;
@ -462,8 +465,11 @@ int extcon_register_interest(struct extcon_specific_cable_nb *obj,
obj->internal_nb.notifier_call = _call_per_cable;
return raw_notifier_chain_register(&obj->edev->nh,
spin_lock_irqsave(&obj->edev->lock, flags);
ret = raw_notifier_chain_register(&obj->edev->nh,
&obj->internal_nb);
spin_unlock_irqrestore(&obj->edev->lock, flags);
return ret;
} else {
struct class_dev_iter iter;
struct extcon_dev *extd;
@ -496,10 +502,17 @@ EXPORT_SYMBOL_GPL(extcon_register_interest);
*/
int extcon_unregister_interest(struct extcon_specific_cable_nb *obj)
{
unsigned long flags;
int ret;
if (!obj)
return -EINVAL;
return raw_notifier_chain_unregister(&obj->edev->nh, &obj->internal_nb);
spin_lock_irqsave(&obj->edev->lock, flags);
ret = raw_notifier_chain_unregister(&obj->edev->nh, &obj->internal_nb);
spin_unlock_irqrestore(&obj->edev->lock, flags);
return ret;
}
EXPORT_SYMBOL_GPL(extcon_unregister_interest);
@ -516,7 +529,14 @@ EXPORT_SYMBOL_GPL(extcon_unregister_interest);
int extcon_register_notifier(struct extcon_dev *edev,
struct notifier_block *nb)
{
return raw_notifier_chain_register(&edev->nh, nb);
unsigned long flags;
int ret;
spin_lock_irqsave(&edev->lock, flags);
ret = raw_notifier_chain_register(&edev->nh, nb);
spin_unlock_irqrestore(&edev->lock, flags);
return ret;
}
EXPORT_SYMBOL_GPL(extcon_register_notifier);
@ -528,7 +548,14 @@ EXPORT_SYMBOL_GPL(extcon_register_notifier);
int extcon_unregister_notifier(struct extcon_dev *edev,
struct notifier_block *nb)
{
return raw_notifier_chain_unregister(&edev->nh, nb);
unsigned long flags;
int ret;
spin_lock_irqsave(&edev->lock, flags);
ret = raw_notifier_chain_unregister(&edev->nh, nb);
spin_unlock_irqrestore(&edev->lock, flags);
return ret;
}
EXPORT_SYMBOL_GPL(extcon_unregister_notifier);