From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.6 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 74869ECDE46 for ; Thu, 25 Oct 2018 14:20:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3C7B7214E0 for ; Thu, 25 Oct 2018 14:20:55 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="mj5ksQx7" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 3C7B7214E0 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731245AbeJYWxu (ORCPT ); Thu, 25 Oct 2018 18:53:50 -0400 Received: from mail.kernel.org ([198.145.29.99]:36510 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729445AbeJYWxt (ORCPT ); Thu, 25 Oct 2018 18:53:49 -0400 Received: from sasha-vm.mshome.net (unknown [167.98.65.38]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id B38B42086D; Thu, 25 Oct 2018 14:20:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1540477251; bh=cbSHfCGldFQfgA6G4YXr5JHdOoC7UICgr8ILQAwk9C8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=mj5ksQx7R8mS/OUUGpqMTZSg7Lyw5sqYa0pUMRIBTPo3xnM0WFCqMAWD7slkjC4cl 5H7RwJ02CA2fkOm//zLO1Ud4LURpAL0n3vU2DaZfUgGponMeUh6CDzPfc9uj7Y+l75 nYu46Rb7oB+CAzmbGBvvH5IUixrAcmLlDBrsDdsk= From: Sasha Levin To: stable@vger.kernel.org, linux-kernel@vger.kernel.org Cc: Joonyoung Shim , linux-samsung-soc@vger.kernel.org, cw00.choi@samsung.com, daniel.lezcano@linaro.org, javier@osg.samsung.com, kgene@kernel.org, krzk@kernel.org, linux-arm-kernel@lists.infradead.org, Thomas Gleixner , Sasha Levin Subject: [PATCH AUTOSEL 3.18 77/98] clocksource/exynos_mct: Clear interrupt when cpu is shut down Date: Thu, 25 Oct 2018 10:18:32 -0400 Message-Id: <20181025141853.214051-77-sashal@kernel.org> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20181025141853.214051-1-sashal@kernel.org> References: <20181025141853.214051-1-sashal@kernel.org> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Joonyoung Shim [ Upstream commit bc7c36eedb0c7004aa06c2afc3c5385adada8fa3 ] 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: stable@vger.kernel.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: Sasha Levin --- drivers/clocksource/exynos_mct.c | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/clocksource/exynos_mct.c b/drivers/clocksource/exynos_mct.c index c844616028d2..714f9a767b17 100644 --- a/drivers/clocksource/exynos_mct.c +++ b/drivers/clocksource/exynos_mct.c @@ -487,6 +487,7 @@ static void exynos4_local_timer_stop(struct clock_event_device *evt) 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]); } -- 2.17.1