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cpuidle: Fix cpuidle_driver_state_disabled()

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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: cbda56d5fe ("cpuidle: Introduce cpuidle_driver_state_disabled() for driver quirks")
Reported-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Tested-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
This commit is contained in:
Rafael J. Wysocki 2019-12-10 12:48:35 +01:00
parent 36fcb42924
commit b0142d66f4
1 changed files with 10 additions and 0 deletions
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10
drivers/cpuidle/driver.c
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@ -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);
}