Policy must be fully initialized before it is being made available for use by others. Otherwise cpufreq_cpu_get() would be able to grab a half initialized policy structure that might not have affected_cpus (for example) filled. And so anybody accessing those fields will get the wrong value and hence the results would be unpredictable.
So, in order to fix this lets do all the necessary initialization before we make policy structure available via cpufreq_cpu_get(). With this we can guarantee that any code accessing fields of policy would be stable enough, as policy would be completely initialized by now.
Signed-off-by: Viresh Kumar viresh.kumar@linaro.org --- V1->V2: - Improved commit logs
drivers/cpufreq/cpufreq.c | 28 ++++++++++++++-------------- 1 file changed, 14 insertions(+), 14 deletions(-)
diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c index fff2968..3c6f9a5 100644 --- a/drivers/cpufreq/cpufreq.c +++ b/drivers/cpufreq/cpufreq.c @@ -1114,6 +1114,20 @@ static int __cpufreq_add_dev(struct device *dev, struct subsys_interface *sif, goto err_set_policy_cpu; }
+ /* related cpus should atleast have policy->cpus */ + cpumask_or(policy->related_cpus, policy->related_cpus, policy->cpus); + + /* + * affected cpus must always be the one, which are online. We aren't + * managing offline cpus here. + */ + cpumask_and(policy->cpus, policy->cpus, cpu_online_mask); + + if (!frozen) { + policy->user_policy.min = policy->min; + policy->user_policy.max = policy->max; + } + write_lock_irqsave(&cpufreq_driver_lock, flags); for_each_cpu(j, policy->cpus) per_cpu(cpufreq_cpu_data, j) = policy; @@ -1167,20 +1181,6 @@ static int __cpufreq_add_dev(struct device *dev, struct subsys_interface *sif, } }
- /* related cpus should atleast have policy->cpus */ - cpumask_or(policy->related_cpus, policy->related_cpus, policy->cpus); - - /* - * affected cpus must always be the one, which are online. We aren't - * managing offline cpus here. - */ - cpumask_and(policy->cpus, policy->cpus, cpu_online_mask); - - if (!frozen) { - policy->user_policy.min = policy->min; - policy->user_policy.max = policy->max; - } - blocking_notifier_call_chain(&cpufreq_policy_notifier_list, CPUFREQ_START, policy);