intel_idle: Fix deallocation order on the driver exit path.

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>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
This commit is contained in:
Richard Cochran 2016-04-06 17:00:51 -04:00 committed by Rafael J. Wysocki
parent 4a3dfb3fc0
commit 51319918bc

View File

@ -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);