From 01b4c9a1ae07a25d208cad0da7dd288007a22984 Mon Sep 17 00:00:00 2001 From: Chanwoo Choi Date: Mon, 19 Dec 2016 21:02:33 +0900 Subject: [PATCH] extcon: Remove potential problem when calling extcon_register_notifier() This patch removes the potential problem of extcon_register_notifier() when edev parameter is NULL. When edev is NULL, this function returns the first extcon device which includes the sepecific external connector of second paramter. But, it don't guarantee the same operation in all cases. To remove this confusion and potential problem, this patch fixes it. Signed-off-by: Chanwoo Choi --- drivers/extcon/extcon.c | 33 +++++++-------------------------- 1 file changed, 7 insertions(+), 26 deletions(-) diff --git a/drivers/extcon/extcon.c b/drivers/extcon/extcon.c index 7c1e3a7b14e0..d0e367959c91 100644 --- a/drivers/extcon/extcon.c +++ b/drivers/extcon/extcon.c @@ -906,35 +906,16 @@ int extcon_register_notifier(struct extcon_dev *edev, unsigned int id, unsigned long flags; int ret, idx = -EINVAL; - if (!nb) + if (!edev || !nb) return -EINVAL; - if (edev) { - idx = find_cable_index_by_id(edev, id); - if (idx < 0) - return idx; - - spin_lock_irqsave(&edev->lock, flags); - ret = raw_notifier_chain_register(&edev->nh[idx], nb); - spin_unlock_irqrestore(&edev->lock, flags); - } else { - struct extcon_dev *extd; - - mutex_lock(&extcon_dev_list_lock); - list_for_each_entry(extd, &extcon_dev_list, entry) { - idx = find_cable_index_by_id(extd, id); - if (idx >= 0) - break; - } - mutex_unlock(&extcon_dev_list_lock); + idx = find_cable_index_by_id(edev, id); + if (idx < 0) + return idx; - if (idx >= 0) { - edev = extd; - return extcon_register_notifier(extd, id, nb); - } else { - ret = -ENODEV; - } - } + spin_lock_irqsave(&edev->lock, flags); + ret = raw_notifier_chain_register(&edev->nh[idx], nb); + spin_unlock_irqrestore(&edev->lock, flags); return ret; } -- 2.20.1