From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753900AbcDFVBt (ORCPT ); Wed, 6 Apr 2016 17:01:49 -0400 Received: from mail-yw0-f193.google.com ([209.85.161.193]:36380 "EHLO mail-yw0-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753802AbcDFVBq (ORCPT ); Wed, 6 Apr 2016 17:01:46 -0400 From: Len Brown To: linux-pm@vger.kernel.org Cc: linux-kernel@vger.kernel.org, Richard Cochran , Len Brown Subject: [PATCH 05/13] intel_idle: Fix deallocation order on the driver exit path. Date: Wed, 6 Apr 2016 17:00:51 -0400 Message-Id: <6baa6b86d4fa30b117145f78459cbedbe96d7e6b.1459975717.git.len.brown@intel.com> X-Mailer: git-send-email 2.8.0.rc4.16.g56331f8 In-Reply-To: <1459976459-2532-1-git-send-email-lenb@kernel.org> References: <1459976459-2532-1-git-send-email-lenb@kernel.org> In-Reply-To: <6513da0f2332d2333848af18e374b99f77c124aa.1459975717.git.len.brown@intel.com> References: <6513da0f2332d2333848af18e374b99f77c124aa.1459975717.git.len.brown@intel.com> Reply-To: Len Brown Organization: Intel Open Source Technology Center Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Richard Cochran In the module_exit() method, this driver first frees its per-CPU pointer, then unregisters a callback making use of the pointer. Furthermore, the function, intel_idle_cpuidle_devices_uninit, is racy against CPU hot plugging as it calls for_each_online_cpu(). This patch corrects the issues by unregistering first on the exit path while holding the hot plug lock. Signed-off-by: Richard Cochran Signed-off-by: Len Brown --- drivers/idle/intel_idle.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/drivers/idle/intel_idle.c b/drivers/idle/intel_idle.c index c50859d..5b309e5 100644 --- a/drivers/idle/intel_idle.c +++ b/drivers/idle/intel_idle.c @@ -1379,16 +1379,16 @@ static int __init intel_idle_init(void) static void __exit intel_idle_exit(void) { - intel_idle_cpuidle_devices_uninit(); - cpuidle_unregister_driver(&intel_idle_driver); - cpu_notifier_register_begin(); if (lapic_timer_reliable_states != LAPIC_TIMER_ALWAYS_RELIABLE) on_each_cpu(__setup_broadcast_timer, (void *)false, 1); __unregister_cpu_notifier(&cpu_hotplug_notifier); + intel_idle_cpuidle_devices_uninit(); cpu_notifier_register_done(); + + cpuidle_unregister_driver(&intel_idle_driver); } module_init(intel_idle_init); -- 2.8.0.rc4.16.g56331f8