diff options
| author | Joonyoung Shim <jy0922.shim@samsung.com> | 2017-01-17 13:54:36 +0900 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2017-01-26 08:23:48 +0100 |
| commit | 098b62b757a4303f576a6d2bb8f11d0ad93797d1 (patch) | |
| tree | 1fbc7a586d6490b3ed4edaf2f8953440ccc7bba7 | |
| parent | a07563c3cf05ead6e08c50513a386261c93b8f33 (diff) | |
clocksource/exynos_mct: Clear interrupt when cpu is shut down
commit bc7c36eedb0c7004aa06c2afc3c5385adada8fa3 upstream.
When a CPU goes offline a potentially pending timer interrupt is not
cleared. When the CPU comes online again then the pending interrupt is
delivered before the per cpu clockevent device is initialized. As a
consequence the tick interrupt handler dereferences a NULL pointer.
[ 51.251378] Unable to handle kernel NULL pointer dereference at virtual address 00000040
[ 51.289348] task: ee942d00 task.stack: ee960000
[ 51.293861] PC is at tick_periodic+0x38/0xb0
[ 51.298102] LR is at tick_handle_periodic+0x1c/0x90
Clear the pending interrupt in the cpu dying path.
Fixes: 56a94f13919c ("clocksource: exynos_mct: Avoid blocking calls in the cpu hotplug notifier")
Reported-by: Seung-Woo Kim <sw0312.kim@samsung.com>
Signed-off-by: Joonyoung Shim <jy0922.shim@samsung.com>
Cc: linux-samsung-soc@vger.kernel.org
Cc: cw00.choi@samsung.com
Cc: daniel.lezcano@linaro.org
Cc: javier@osg.samsung.com
Cc: kgene@kernel.org
Cc: krzk@kernel.org
Cc: linux-arm-kernel@lists.infradead.org
Link: http://lkml.kernel.org/r/1484628876-22065-1-git-send-email-jy0922.shim@samsung.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/clocksource/exynos_mct.c | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/drivers/clocksource/exynos_mct.c b/drivers/clocksource/exynos_mct.c index ff44082a0827..47f8aafe3344 100644 --- a/drivers/clocksource/exynos_mct.c +++ b/drivers/clocksource/exynos_mct.c @@ -482,6 +482,7 @@ static void exynos4_local_timer_stop(struct mct_clock_event_device *mevt) if (mct_int_type == MCT_INT_SPI) { if (evt->irq != -1) disable_irq_nosync(evt->irq); + exynos4_mct_write(0x1, mevt->base + MCT_L_INT_CSTAT_OFFSET); } else { disable_percpu_irq(mct_irqs[MCT_L0_IRQ]); } |