From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:40388 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750714AbdAWOer (ORCPT ); Mon, 23 Jan 2017 09:34:47 -0500 Subject: Patch "clocksource/exynos_mct: Clear interrupt when cpu is shut down" has been added to the 4.4-stable tree To: jy0922.shim@samsung.com, gregkh@linuxfoundation.org, sw0312.kim@samsung.com, tglx@linutronix.de Cc: , From: Date: Mon, 23 Jan 2017 15:34:41 +0100 Message-ID: <1485182081218167@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org List-ID: This is a note to let you know that I've just added the patch titled clocksource/exynos_mct: Clear interrupt when cpu is shut down to the 4.4-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: clocksource-exynos_mct-clear-interrupt-when-cpu-is-shut-down.patch and it can be found in the queue-4.4 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let know about it. >>From bc7c36eedb0c7004aa06c2afc3c5385adada8fa3 Mon Sep 17 00:00:00 2001 From: Joonyoung Shim Date: Tue, 17 Jan 2017 13:54:36 +0900 Subject: clocksource/exynos_mct: Clear interrupt when cpu is shut down From: Joonyoung Shim 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 Signed-off-by: Joonyoung Shim 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 Signed-off-by: Greg Kroah-Hartman --- drivers/clocksource/exynos_mct.c | 1 + 1 file changed, 1 insertion(+) --- a/drivers/clocksource/exynos_mct.c +++ b/drivers/clocksource/exynos_mct.c @@ -482,6 +482,7 @@ static void exynos4_local_timer_stop(str 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]); } Patches currently in stable-queue which might be from jy0922.shim@samsung.com are queue-4.4/clocksource-exynos_mct-clear-interrupt-when-cpu-is-shut-down.patch