From: Michael Buesch Date: Tue, 6 Jan 2009 22:43:14 +0000 (-0800) Subject: parport: ieee1284: use del_timer_sync() in parport_wait_event() X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=f59abb161c955b68fd3d473368420c5919733e09;p=GitHub%2FLineageOS%2Fandroid_kernel_samsung_universal7580.git parport: ieee1284: use del_timer_sync() in parport_wait_event() Use del_timer_sync() instead of del_timer() to make sure the timer won't be running when we return from parport_wait_event(), because this would crash due to destruction of timer_list. This is untested and just based on a code review. Just think about the following sequence of events: - add_timer() - down_interruptible() is interrupted by a signal. - we enter the timer callback handler on another CPU. - del_timer(), but the timer callback is still running. - eturn from parport_wait_even, which destroys the automatic variable "timer" while the callback is running on another CPU. [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Michael Buesch Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- diff --git a/drivers/parport/ieee1284.c b/drivers/parport/ieee1284.c index ac2a805ac7e..8901ecf6e03 100644 --- a/drivers/parport/ieee1284.c +++ b/drivers/parport/ieee1284.c @@ -84,7 +84,7 @@ int parport_wait_event (struct parport *port, signed long timeout) add_timer (&timer); ret = down_interruptible (&port->physport->ieee1284.irq); - if (!del_timer (&timer) && !ret) + if (!del_timer_sync(&timer) && !ret) /* Timed out. */ ret = 1;