Re: [PATCH Resend] cpufreq: Set cpufreq_cpu_data to NULL before putting kobject

[ethan zhao <ethan.zhao@oracle.com>]

On 2015/2/2 12:09, Viresh Kumar wrote:
> On 2 February 2015 at 09:36, ethan zhao <ethan.zhao@oracle.com> wrote:
>>   Is that an idea it supposed to be or fact ?
>>
>> if (!cpufreq_suspended)
>>              cpufreq_policy_free(policy);
>>
>>   static void cpufreq_policy_free(struct cpufreq_policy *policy)
>> {
>>      free_cpumask_var(policy->related_cpus);
>>      free_cpumask_var(policy->cpus);
>>      kfree(policy);
>> }
>>
>>   It seems
>>   you just think about it ideally in mind.
  We am talking about the policy allocation and de-allocation. right ?
  I showed you the cpufreq_policy_free(policy) doesn't check kobject
  refcount  as above.

  Hmmm, you are still sleeping in the kobject, wake up and don't mix
  water anymore.

Thanks,
Ethan


> if (!cpufreq_suspended)
>          cpufreq_policy_put_kobj(policy);
>
> static void cpufreq_policy_put_kobj(struct cpufreq_policy *policy)
> {
>          ...
>
>          kobject_put(kobj);
>
>          /*
>          * We need to make sure that the underlying kobj is
>          * actually not referenced anymore by anybody before we
>          * proceed with unloading.
>          */
>          pr_debug("waiting for dropping of refcount\n");
>          wait_for_completion(cmp);
> }