Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 45fe4fe1 authored by Ingo Molnar's avatar Ingo Molnar
Browse files

x86: make clockevents more robust 



detect zero event-device multiplicators - they then cause
division-by-zero crashes if a clockevent has been initialized
incorrectly.

Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
parent 1a0c009a

kernel/time/clockevents.c

+13 −0
Original line number Diff line number Diff line
@@ -41,6 +41,11 @@ unsigned long clockevent_delta2ns(unsigned long latch, 
{

	u64 clc = ((u64) latch << evt->shift);



	if (unlikely(!evt->mult)) {

		evt->mult = 1;

		WARN_ON(1);

	}



	do_div(clc, evt->mult);

	if (clc < 1000)

		clc = 1000;
@@ -151,6 +156,14 @@ static void clockevents_notify_released(void) 
void clockevents_register_device(struct clock_event_device *dev)

{

	BUG_ON(dev->mode != CLOCK_EVT_MODE_UNUSED);

	/*

	 * A nsec2cyc multiplicator of 0 is invalid and we'd crash

	 * on it, so fix it up and emit a warning:

	 */

	if (unlikely(!dev->mult)) {

		dev->mult = 1;

		WARN_ON(1);

	}



	spin_lock(&clockevents_lock);