From b0142d66f4edb8578b7772d6d7ad731836b82ddb Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Tue, 10 Dec 2019 12:48:35 +0100 Subject: cpuidle: Fix cpuidle_driver_state_disabled() It turns out that cpuidle_driver_state_disabled() can be called before registering the cpufreq driver on some platforms, which was not expected when it was introduced and which leads to a NULL pointer dereference when trying to walk the CPUs associated with the given cpuidle driver. Fix the problem by making cpuidle_driver_state_disabled() check if the driver's mask of CPUs associated with it is present and to set CPUIDLE_FLAG_UNUSABLE for the given idle state in the driver's states list if that is not the case to cause __cpuidle_register_device() to set CPUIDLE_STATE_DISABLED_BY_DRIVER for that state for all cpuidle devices registered by it later. Fixes: cbda56d5fefc ("cpuidle: Introduce cpuidle_driver_state_disabled() for driver quirks") Reported-by: Daniel Lezcano Tested-by: Daniel Lezcano Signed-off-by: Rafael J. Wysocki --- drivers/cpuidle/driver.c | 10 ++++++++++ 1 file changed, 10 insertions(+) (limited to 'drivers/cpuidle') diff --git a/drivers/cpuidle/driver.c b/drivers/cpuidle/driver.c index c76423aaef4d..ce6a5f80fb83 100644 --- a/drivers/cpuidle/driver.c +++ b/drivers/cpuidle/driver.c @@ -403,6 +403,13 @@ void cpuidle_driver_state_disabled(struct cpuidle_driver *drv, int idx, mutex_lock(&cpuidle_lock); + spin_lock(&cpuidle_driver_lock); + + if (!drv->cpumask) { + drv->states[idx].flags |= CPUIDLE_FLAG_UNUSABLE; + goto unlock; + } + for_each_cpu(cpu, drv->cpumask) { struct cpuidle_device *dev = per_cpu(cpuidle_devices, cpu); @@ -415,5 +422,8 @@ void cpuidle_driver_state_disabled(struct cpuidle_driver *drv, int idx, dev->states_usage[idx].disable &= ~CPUIDLE_STATE_DISABLED_BY_DRIVER; } +unlock: + spin_unlock(&cpuidle_driver_lock); + mutex_unlock(&cpuidle_lock); } -- cgit v1.2.3