Power management and ACPI fixes for v4.3-rc5

- Two fixes for cpufreq regressions, an acpi-cpufreq driver one
    introduced during the 4.2 cycle when we started to preserve
    cpufreq directories for offline CPUs and a general one
    introduced recently (Srinivas Pandruvada).
 
  - Two devfreq fixes, one for a double kfree() in an error code
    path and one for a confusing sysfs-related failure (Geliang Tang,
    Tobias Jakobi).
 
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Merge tag 'pm+acpi-4.3-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

Pull power management and ACPI fixes from Rafael Wysocki:
 "These are four fixes for bugs in the devfreq and cpufreq subsystems,
  including two regression fixes (one for a recent regression and one
  for a problem introduced in 4.2).

  Specifics:

   - Two fixes for cpufreq regressions, an acpi-cpufreq driver one
     introduced during the 4.2 cycle when we started to preserve cpufreq
     directories for offline CPUs and a general one introduced recently
     (Srinivas Pandruvada).

   - Two devfreq fixes, one for a double kfree() in an error code path
     and one for a confusing sysfs-related failure (Geliang Tang, Tobias
     Jakobi)"

* tag 'pm+acpi-4.3-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  cpufreq: prevent lockup on reading scaling_available_frequencies
  cpufreq: acpi_cpufreq: prevent crash on reading freqdomain_cpus
  PM / devfreq: fix double kfree
  PM / devfreq: Fix governor_store()

drivers/cpufreq/acpi-cpufreq.c

@@ -149,6 +149,9 @@ static ssize_t show_freqdomain_cpus(struct cpufreq_policy *policy, char *buf)
 {
 	struct acpi_cpufreq_data *data = policy->driver_data;
 
+	if (unlikely(!data))
+		return -ENODEV;
+
 	return cpufreq_show_cpus(data->freqdomain_cpus, buf);
 }
 

drivers/cpufreq/cpufreq.c

@@ -1436,8 +1436,10 @@ static void cpufreq_offline_finish(unsigned int cpu)
 	 * since this is a core component, and is essential for the
 	 * subsequent light-weight ->init() to succeed.
 	 */
-	if (cpufreq_driver->exit)
+	if (cpufreq_driver->exit) {
 		cpufreq_driver->exit(policy);
+		policy->freq_table = NULL;
+	}
 }
 
 /**

drivers/devfreq/devfreq.c

@@ -492,7 +492,7 @@ struct devfreq *devfreq_add_device(struct device *dev,
 	if (err) {
 		put_device(&devfreq->dev);
 		mutex_unlock(&devfreq->lock);
-		goto err_dev;
+		goto err_out;
 	}
 
 	mutex_unlock(&devfreq->lock);
@@ -518,7 +518,6 @@ struct devfreq *devfreq_add_device(struct device *dev,
 err_init:
 	list_del(&devfreq->node);
 	device_unregister(&devfreq->dev);
-err_dev:
 	kfree(devfreq);
 err_out:
 	return ERR_PTR(err);
@@ -795,8 +794,10 @@ static ssize_t governor_store(struct device *dev, struct device_attribute *attr,
 		ret = PTR_ERR(governor);
 		goto out;
 	}
-	if (df->governor == governor)
+	if (df->governor == governor) {
+		ret = 0;
 		goto out;
+	}
 
 	if (df->governor) {
 		ret = df->governor->event_handler(df, DEVFREQ_GOV_STOP, NULL);