From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752985AbdJTLsJ (ORCPT ); Fri, 20 Oct 2017 07:48:09 -0400 Received: from terminus.zytor.com ([65.50.211.136]:59779 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752649AbdJTLsH (ORCPT ); Fri, 20 Oct 2017 07:48:07 -0400 Date: Fri, 20 Oct 2017 04:45:52 -0700 From: tip-bot for David Kozub Message-ID: Cc: tglx@linutronix.de, hpa@zytor.com, daniel.lezcano@linaro.org, linux-kernel@vger.kernel.org, zub@linux.fjfi.cvut.cz, mingo@kernel.org Reply-To: zub@linux.fjfi.cvut.cz, linux-kernel@vger.kernel.org, mingo@kernel.org, hpa@zytor.com, tglx@linutronix.de, daniel.lezcano@linaro.org In-Reply-To: <20171020093103.3317F6004D@linux.fjfi.cvut.cz> References: <20171020093103.3317F6004D@linux.fjfi.cvut.cz> To: linux-tip-commits@vger.kernel.org Subject: [tip:timers/urgent] clockevents/drivers/cs5535: Improve resilience to spurious interrupts Git-Commit-ID: eb39a7c0355393c5a8d930f342ad7a6231b552c4 X-Mailer: tip-git-log-daemon Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit-ID: eb39a7c0355393c5a8d930f342ad7a6231b552c4 Gitweb: https://git.kernel.org/tip/eb39a7c0355393c5a8d930f342ad7a6231b552c4 Author: David Kozub AuthorDate: Thu, 19 Oct 2017 22:57:02 +0200 Committer: Thomas Gleixner CommitDate: Fri, 20 Oct 2017 13:41:52 +0200 clockevents/drivers/cs5535: Improve resilience to spurious interrupts The interrupt handler mfgpt_tick() is not robust versus spurious interrupts which happen before the clock event device is registered and fully initialized. The reason is that the safe guard against spurious interrupts solely checks for the clockevents shutdown state, but lacks a check for detached state. If the interrupt hits while the device is in detached state it passes the safe guard and dereferences the event handler call back which is NULL. Add the missing state check. Fixes: 8f9327cbb6e8 ("clockevents/drivers/cs5535: Migrate to new 'set-state' interface") Suggested-by: Thomas Gleixner Signed-off-by: David Kozub Signed-off-by: Thomas Gleixner Cc: Daniel Lezcano Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/20171020093103.3317F6004D@linux.fjfi.cvut.cz --- drivers/clocksource/cs5535-clockevt.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/clocksource/cs5535-clockevt.c b/drivers/clocksource/cs5535-clockevt.c index a1df588..1de8cac 100644 --- a/drivers/clocksource/cs5535-clockevt.c +++ b/drivers/clocksource/cs5535-clockevt.c @@ -117,7 +117,8 @@ static irqreturn_t mfgpt_tick(int irq, void *dev_id) /* Turn off the clock (and clear the event) */ disable_timer(cs5535_event_clock); - if (clockevent_state_shutdown(&cs5535_clockevent)) + if (clockevent_state_detached(&cs5535_clockevent) || + clockevent_state_shutdown(&cs5535_clockevent)) return IRQ_HANDLED; /* Clear the counter */