From 59b015133cd0034f5904a76969d73476380aac46 Mon Sep 17 00:00:00 2001 From: "Eric W. Biederman" Date: Tue, 5 Jan 2010 17:56:02 -0800 Subject: Input: serio - fix potential deadlock when unbinding drivers sysfs_remove_group() waits for sysfs attributes to be removed, therefore we do not need to worry about driver-specific attributes being accessed after driver has been detached from the device. In fact, attempts to take serio->drv_mutex in attribute methods may lead to the following deadlock: sysfs_read_file() fill_read_buffer() sysfs_get_active_two() psmouse_attr_show_helper() serio_pin_driver() serio_disconnect_driver() mutex_lock(&serio->drv_mutex); <--------> mutex_lock(&serio_drv_mutex); psmouse_disconnect() sysfs_remove_group(... psmouse_attr_group); .... sysfs_deactivate(); wait_for_completion(); Fix this by removing calls to serio_[un]pin_driver() and functions themselves and using driver-private mutexes to serialize access to attribute's set() methods that may change device state. Signed-off-by: Eric W. Biederman Signed-off-by: Dmitry Torokhov --- include/linux/serio.h | 19 ------------------- 1 file changed, 19 deletions(-) (limited to 'include/linux') diff --git a/include/linux/serio.h b/include/linux/serio.h index e2f3044..813d26c 100644 --- a/include/linux/serio.h +++ b/include/linux/serio.h @@ -136,25 +136,6 @@ static inline void serio_continue_rx(struct serio *serio) spin_unlock_irq(&serio->lock); } -/* - * Use the following functions to pin serio's driver in process context - */ -static inline int serio_pin_driver(struct serio *serio) -{ - return mutex_lock_interruptible(&serio->drv_mutex); -} - -static inline void serio_pin_driver_uninterruptible(struct serio *serio) -{ - mutex_lock(&serio->drv_mutex); -} - -static inline void serio_unpin_driver(struct serio *serio) -{ - mutex_unlock(&serio->drv_mutex); -} - - #endif /* -- cgit v1.1