From: Len Brown <lenb@kernel.org>
To: linux-pm@vger.kernel.org
Cc: linux-kernel@vger.kernel.org,
Richard Cochran <rcochran@linutronix.de>,
Len Brown <len.brown@intel.com>
Subject: [PATCH 05/13] intel_idle: Fix deallocation order on the driver exit path.
Date: Wed, 6 Apr 2016 17:00:51 -0400 [thread overview]
Message-ID: <6baa6b86d4fa30b117145f78459cbedbe96d7e6b.1459975717.git.len.brown@intel.com> (raw)
In-Reply-To: <1459976459-2532-1-git-send-email-lenb@kernel.org>
In-Reply-To: <6513da0f2332d2333848af18e374b99f77c124aa.1459975717.git.len.brown@intel.com>
From: Richard Cochran <rcochran@linutronix.de>
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 <rcochran@linutronix.de>
Signed-off-by: Len Brown <len.brown@intel.com>
---
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
next prev parent reply other threads:[~2016-04-06 21:01 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-04-06 21:00 [PATCH 0/13] intel_idle patches ready for upstream Len Brown
2016-04-06 21:00 ` [PATCH 01/13] intel_idle: add BXT support Len Brown
2016-04-06 21:00 ` [PATCH 02/13] intel_idle: remove useless return from void function Len Brown
2016-04-06 21:00 ` [PATCH 03/13] intel_idle: Fix a helper function's return value Len Brown
2016-04-06 21:00 ` [PATCH 04/13] intel_idle: Remove redundant initialization calls Len Brown
2016-04-06 21:00 ` Len Brown [this message]
2016-04-06 21:00 ` [PATCH 06/13] intel_idle: Fix dangling registration on error path Len Brown
2016-04-06 21:00 ` [PATCH 07/13] intel_idle: Avoid a double free of the per-CPU data Len Brown
2016-04-06 21:00 ` [PATCH 08/13] intel_idle: Setup the timer broadcast only on successful driver load Len Brown
2016-04-06 21:00 ` [PATCH 09/13] intel_idle: Don't overreact to a cpuidle registration failure Len Brown
2016-04-06 21:00 ` [PATCH 10/13] intel_idle: Propagate hot plug errors Len Brown
2016-04-06 21:00 ` [PATCH 11/13] intel_idle: Clean up all registered devices on exit Len Brown
2016-04-06 21:00 ` [PATCH 12/13] intel_idle: Add SKX support Len Brown
2016-04-06 21:00 ` [PATCH 13/13] intel_idle: Add KBL support Len Brown
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