Commit ceda408c authored by Xion Wang's avatar Xion Wang Committed by Greg Kroah-Hartman
Browse files

misc: remove ineffective WARN_ON() check from misc_deregister() 



The WARN_ON(list_empty(&misc->list)) in misc_deregister() does
not catch any practical error conditions:
- For statically allocated miscdevice structures, the list pointers
 are zero-initialized, so list_empty() returns false, not true.
- After list_del(), the pointers are set to LIST_POISON1 and LIST_POISON2,
 so repeated deregistration also fails to trigger the check.

Signed-off-by: default avatarXion Wang <xion.wang@mediatek.com>
Link: https://lore.kernel.org/r/20250827024201.21407-2-xion.wang@mediatek.com


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 20f2044b

drivers/char/misc.c

+0 −3
Original line number Diff line number Diff line
@@ -283,9 +283,6 @@ EXPORT_SYMBOL(misc_register); 


void misc_deregister(struct miscdevice *misc)

{

	if (WARN_ON(list_empty(&misc->list)))

		return;



	mutex_lock(&misc_mtx);

	list_del(&misc->list);

	device_destroy(&misc_class, MKDEV(MISC_MAJOR, misc->minor));