Re: [PATCH] cpufreq: Avoid double kobject_put() for the same kobjectin error code path

From: Srivatsa S. Bhat
Date: Fri Aug 02 2013 - 02:57:47 EST


On 08/02/2013 03:01 AM, Rafael J. Wysocki wrote:
> From: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
>
> The only case triggering a jump to the err_out_unregister label in
> __cpufreq_add_dev() is when cpufreq_add_dev_interface() fails.
> However, if cpufreq_add_dev_interface() fails, it calls kobject_put()
> for the policy kobject in its error code path and since that causes
> the kobject's refcount to become 0, the additional kobject_put() for
> the same kobject under err_out_unregister and the
> wait_for_completion() following it are pointless, so drop them.
>
> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>

Reviewed-by: Srivatsa S. Bhat <srivatsa.bhat@xxxxxxxxxxxxxxxxxx>

Regards,
Srivatsa S. Bhat

> ---
> drivers/cpufreq/cpufreq.c | 3 ---
> 1 file changed, 3 deletions(-)
>
> Index: linux-pm/drivers/cpufreq/cpufreq.c
> ===================================================================
> --- linux-pm.orig/drivers/cpufreq/cpufreq.c
> +++ linux-pm/drivers/cpufreq/cpufreq.c
> @@ -1109,9 +1109,6 @@ err_out_unregister:
> }
> write_unlock_irqrestore(&cpufreq_driver_lock, flags);
>
> - kobject_put(&policy->kobj);
> - wait_for_completion(&policy->kobj_unregister);
> -
> err_set_policy_cpu:
> per_cpu(cpufreq_policy_cpu, cpu) = -1;
> cpufreq_policy_free(policy);
>

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