diff options
| author | Mark Rutland <mark.rutland@arm.com> | 2013-03-07 15:09:24 +0000 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2013-03-28 12:12:26 -0700 |
| commit | 8d96fcec68c30196fca01a75a911835c7b89a50d (patch) | |
| tree | 1a5524de1f2dda9b4426e941f7955eb854d8bc22 | |
| parent | 3d2e7424b3e18dc851a4b0efdc6676c09573f55f (diff) | |
clockevents: Don't allow dummy broadcast timers
commit a7dc19b8652c862d5b7c4d2339bd3c428bd29c4a upstream.
Currently tick_check_broadcast_device doesn't reject clock_event_devices
with CLOCK_EVT_FEAT_DUMMY, and may select them in preference to real
hardware if they have a higher rating value. In this situation, the
dummy timer is responsible for broadcasting to itself, and the core
clockevents code may attempt to call non-existent callbacks for
programming the dummy, eventually leading to a panic.
This patch makes tick_check_broadcast_device always reject dummy timers,
preventing this problem.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: Jon Medhurst (Tixy) <tixy@linaro.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | kernel/time/tick-broadcast.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/kernel/time/tick-broadcast.c b/kernel/time/tick-broadcast.c index f113755695e..a13987af44f 100644 --- a/kernel/time/tick-broadcast.c +++ b/kernel/time/tick-broadcast.c @@ -66,7 +66,8 @@ static void tick_broadcast_start_periodic(struct clock_event_device *bc) */ int tick_check_broadcast_device(struct clock_event_device *dev) { - if ((tick_broadcast_device.evtdev && + if ((dev->features & CLOCK_EVT_FEAT_DUMMY) || + (tick_broadcast_device.evtdev && tick_broadcast_device.evtdev->rating >= dev->rating) || (dev->features & CLOCK_EVT_FEAT_C3STOP)) return 0; |