Re: [PATCH 1/3][RESEND] cpufreq: qcom-cpufreq-hw: Avoid stack buffer for IRQ name

[Bjorn Andersson <bjorn.andersson@linaro.org>]

On Thu 11 Nov 09:48 CST 2021, Vladimir Zapolskiy wrote:

> From: Ard Biesheuvel <ardb@kernel.org>
> 
> Registering an IRQ requires the string buffer containing the name to
> remain allocated, as the name is not copied into another buffer.
> 
> So let's add a irq_name field to the data struct instead, which is
> guaranteed to have the appropriate lifetime.
> 
> Cc: Thara Gopinath <thara.gopinath@linaro.org>
> Cc: Bjorn Andersson <bjorn.andersson@linaro.org>
> Cc: Andy Gross <agross@kernel.org>
> Cc: linux-arm-msm@vger.kernel.org
> Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
> Reviewed-by: Thara Gopinath <thara.gopinath@linaro.org>
> Tested-by: Steev Klimaszewski <steev@kali.org>
> Signed-off-by: Vladimir Zapolskiy <vladimir.zapolskiy@linaro.org>

Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>

Thanks for reposting this Vladimir.

Regards,
Bjorn

> ---
> vzapolskiy: rebased, added all collected tags and resend the change from Ard
> 
>  drivers/cpufreq/qcom-cpufreq-hw.c | 8 ++++----
>  1 file changed, 4 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/cpufreq/qcom-cpufreq-hw.c b/drivers/cpufreq/qcom-cpufreq-hw.c
> index a2be0df7e174..3b5835336658 100644
> --- a/drivers/cpufreq/qcom-cpufreq-hw.c
> +++ b/drivers/cpufreq/qcom-cpufreq-hw.c
> @@ -46,6 +46,7 @@ struct qcom_cpufreq_data {
>  	 */
>  	struct mutex throttle_lock;
>  	int throttle_irq;
> +	char irq_name[15];
>  	bool cancel_throttle;
>  	struct delayed_work throttle_work;
>  	struct cpufreq_policy *policy;
> @@ -375,7 +376,6 @@ static int qcom_cpufreq_hw_lmh_init(struct cpufreq_policy *policy, int index)
>  {
>  	struct qcom_cpufreq_data *data = policy->driver_data;
>  	struct platform_device *pdev = cpufreq_get_driver_data();
> -	char irq_name[15];
>  	int ret;
>  
>  	/*
> @@ -392,11 +392,11 @@ static int qcom_cpufreq_hw_lmh_init(struct cpufreq_policy *policy, int index)
>  	mutex_init(&data->throttle_lock);
>  	INIT_DEFERRABLE_WORK(&data->throttle_work, qcom_lmh_dcvs_poll);
>  
> -	snprintf(irq_name, sizeof(irq_name), "dcvsh-irq-%u", policy->cpu);
> +	snprintf(data->irq_name, sizeof(data->irq_name), "dcvsh-irq-%u", policy->cpu);
>  	ret = request_threaded_irq(data->throttle_irq, NULL, qcom_lmh_dcvs_handle_irq,
> -				   IRQF_ONESHOT, irq_name, data);
> +				   IRQF_ONESHOT, data->irq_name, data);
>  	if (ret) {
> -		dev_err(&pdev->dev, "Error registering %s: %d\n", irq_name, ret);
> +		dev_err(&pdev->dev, "Error registering %s: %d\n", data->irq_name, ret);
>  		return 0;
>  	}
>  
> -- 
> 2.32.0
>