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| author | Mark Rutland <mark.rutland@arm.com> | 2013-03-07 16:09:24 +0100 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2013-03-07 17:16:11 +0100 |
| commit | a7dc19b8652c862d5b7c4d2339bd3c428bd29c4a (patch) | |
| tree | cc31aa42ae65ec413ae1ee586307cf8687fdbc92 /kernel/time | |
| parent | Linux 3.9-rc1 (diff) | |
| download | linux-a7dc19b8652c862d5b7c4d2339bd3c428bd29c4a.tar.xz linux-a7dc19b8652c862d5b7c4d2339bd3c428bd29c4a.zip | |
clockevents: Don't allow dummy broadcast timers
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>
Cc: stable@vger.kernel.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Diffstat (limited to 'kernel/time')
| -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 2fb8cb88df8d..7f32fe0e52cd 100644 --- a/kernel/time/tick-broadcast.c +++ b/kernel/time/tick-broadcast.c @@ -67,7 +67,8 @@ 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; |