diff mbox

cpufreq: Avoid double kobject_put() for the same kobject in error code path

Message ID 2204970.DYsqYi7YjZ@vostro.rjw.lan (mailing list archive)
State Accepted, archived
Headers show

Commit Message

Rafael Wysocki Aug. 1, 2013, 9:31 p.m. UTC 
From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

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@intel.com>
---
 drivers/cpufreq/cpufreq.c |    3 ---
 1 file changed, 3 deletions(-)


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Comments

Srivatsa S. Bhat Aug. 2, 2013, 6:54 a.m. UTC | #1 
On 08/02/2013 03:01 AM, Rafael J. Wysocki wrote:
> From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
> 
> 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@intel.com>

Reviewed-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>

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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diff mbox

Patch

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);