Re: [PATCH] cpufreq: brcmstb-avs-cpufreq: Fix some resource leaks in the error handling path of the probe function

[Viresh Kumar]

On 19-12-20, 11:17, Christophe JAILLET wrote:
> If 'cpufreq_register_driver()' fails, we must release the resources
> allocated in 'brcm_avs_prepare_init()' as already done in the remove
> function.
> 
> To do that, introduce a new function 'brcm_avs_prepare_uninit()' in order
> to avoid code duplication. This also makes the code more readable (IMHO).
> 
> Fixes: de322e085995 ("cpufreq: brcmstb-avs-cpufreq: AVS CPUfreq driver for 
> Broadcom STB SoCs")
> Signed-off-by: Christophe JAILLET <christophe.jail...@wanadoo.fr>
> ---
> I'm not sure that the existing error handling in the remove function is
> correct and/or needed.
> ---
>  drivers/cpufreq/brcmstb-avs-cpufreq.c | 25 ++++++++++++++++++++-----
>  1 file changed, 20 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/cpufreq/brcmstb-avs-cpufreq.c 
> b/drivers/cpufreq/brcmstb-avs-cpufreq.c
> index 3e31e5d28b79..750ca7cfccb0 100644
> --- a/drivers/cpufreq/brcmstb-avs-cpufreq.c
> +++ b/drivers/cpufreq/brcmstb-avs-cpufreq.c
> @@ -597,6 +597,16 @@ static int brcm_avs_prepare_init(struct platform_device 
> *pdev)
>       return ret;
>  }
>  
> +static void brcm_avs_prepare_uninit(struct platform_device *pdev)
> +{
> +     struct private_data *priv;
> +
> +     priv = platform_get_drvdata(pdev);
> +
> +     iounmap(priv->avs_intr_base);
> +     iounmap(priv->base);
> +}
> +
>  static int brcm_avs_cpufreq_init(struct cpufreq_policy *policy)
>  {
>       struct cpufreq_frequency_table *freq_table;
> @@ -732,21 +742,26 @@ static int brcm_avs_cpufreq_probe(struct 
> platform_device *pdev)
>  
>       brcm_avs_driver.driver_data = pdev;
>  
> -     return cpufreq_register_driver(&brcm_avs_driver);
> +     ret = cpufreq_register_driver(&brcm_avs_driver);
> +     if (ret)
> +             goto err_uninit;
> +
> +     return 0;
> +
> +err_uninit:
> +     brcm_avs_prepare_uninit(pdev);
> +     return ret;

Maybe rewrite as:

        ret = cpufreq_register_driver(&brcm_avs_driver);
        if (ret)
                brcm_avs_prepare_uninit(pdev);
        return ret;

>  }
>  
>  static int brcm_avs_cpufreq_remove(struct platform_device *pdev)
>  {
> -     struct private_data *priv;
>       int ret;
>  
>       ret = cpufreq_unregister_driver(&brcm_avs_driver);
>       if (ret)
>               return ret;

Instead of returning here, it can be just WARN_ON(ret); and then go on and free
the resources and this needs to be done in a separate patch.

>  
> -     priv = platform_get_drvdata(pdev);
> -     iounmap(priv->base);
> -     iounmap(priv->avs_intr_base);
> +     brcm_avs_prepare_uninit(pdev);
>  
>       return 0;
>  }

-- 
viresh