From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752617AbaCWPJd (ORCPT ); Sun, 23 Mar 2014 11:09:33 -0400 Received: from www.linutronix.de ([62.245.132.108]:58099 "EHLO Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752386AbaCWPJX (ORCPT ); Sun, 23 Mar 2014 11:09:23 -0400 Message-Id: <20140323150754.272874059@linutronix.de> User-Agent: quilt/0.60-1 Date: Sun, 23 Mar 2014 15:09:32 -0000 From: Thomas Gleixner To: LKML Cc: Julia Lawall , Andrew Morton , "Rafael J. Wysocki" , cpufreq , pm Subject: [patch 15/16] cpufreq: intel-pstate: Use del_timer_sync in intel_pstate_cpu_exit() References: <20140323150557.288925975@linutronix.de> Content-Disposition: inline; filename=cpufreq-intel-pstate-use-del_timer_sync.patch X-Linutronix-Spam-Score: -1.0 X-Linutronix-Spam-Level: - X-Linutronix-Spam-Status: No , -1.0 points, 5.0 required, ALL_TRUSTED=-1,SHORTCIRCUIT=-0.0001 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org We are about to free the data structure. Make sure no timer callback is running. I might be paranoid, but the ->exit callback can be invoked from so many places, that it is not entirely clear whether del_timer is always called on the cpu on which it is enqueued. While looking through the call sites I noticed, that cpufreq_init_policy() can fail and invoke cpufreq_driver->exit() but it does not return the failure and the callsite happily proceeds. Signed-off-by: Thomas Gleixner Cc: "Rafael J. Wysocki" Cc: cpufreq Cc: pm --- drivers/cpufreq/intel_pstate.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) Index: tip/drivers/cpufreq/intel_pstate.c =================================================================== --- tip.orig/drivers/cpufreq/intel_pstate.c +++ tip/drivers/cpufreq/intel_pstate.c @@ -777,7 +777,7 @@ static int intel_pstate_cpu_exit(struct { int cpu = policy->cpu; - del_timer(&all_cpu_data[cpu]->timer); + del_timer_sync(&all_cpu_data[cpu]->timer); kfree(all_cpu_data[cpu]); all_cpu_data[cpu] = NULL; return 0;