Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756872AbcC2NRc (ORCPT ); Tue, 29 Mar 2016 09:17:32 -0400 Received: from www.linutronix.de ([62.245.132.108]:54670 "EHLO Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756107AbcC2NQF (ORCPT ); Tue, 29 Mar 2016 09:16:05 -0400 From: Richard Cochran To: Cc: , Len Brown , linux-pm@vger.kernel.org Subject: [PATCH 04/10] intel_idle: Fix deallocation order on the driver exit path. Date: Tue, 29 Mar 2016 15:15:56 +0200 Message-Id: X-Mailer: git-send-email 1.7.10.4 In-Reply-To: References: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1318 Lines: 41 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. Cc: Len Brown Cc: linux-pm@vger.kernel.org Signed-off-by: Richard Cochran --- 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 cb85c4c..4a1de3d 100644 --- a/drivers/idle/intel_idle.c +++ b/drivers/idle/intel_idle.c @@ -1242,16 +1242,16 @@ 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); -- 2.1.4