Re: [PATCH v3] cpufreq: cppc: Set fie_disabled to FIE_DISABLED if fails to create kworker_fie

[Viresh Kumar <viresh.kumar@linaro.org>]

On 17-08-23, 07:47, Liao Chang wrote:
> The function cppc_freq_invariance_init() may failed to create
> kworker_fie, make it more robust by setting fie_disabled to FIE_DISBALED
> to prevent an invalid pointer dereference in kthread_destroy_worker(),
> which called from cppc_freq_invariance_exit().
> 
> v3:
> Simplify cleanup code when invariance initialization fails.
> 
> v2:
> Set fie_disabled to FIE_DISABLED when invariance initialization fails.
> 
> Link: https://lore.kernel.org/all/20230816034630.a4hvsj373q6aslk3@vireshk-i7/
> 
> Signed-off-by: Liao Chang <liaochang1@huawei.com>
> ---
>  drivers/cpufreq/cppc_cpufreq.c | 9 ++++++---
>  1 file changed, 6 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/cpufreq/cppc_cpufreq.c b/drivers/cpufreq/cppc_cpufreq.c
> index 022e3555407c..4d501f0bf55d 100644
> --- a/drivers/cpufreq/cppc_cpufreq.c
> +++ b/drivers/cpufreq/cppc_cpufreq.c
> @@ -249,15 +249,19 @@ static void __init cppc_freq_invariance_init(void)
>  		return;
>  
>  	kworker_fie = kthread_create_worker(0, "cppc_fie");
> -	if (IS_ERR(kworker_fie))
> +	if (IS_ERR(kworker_fie)) {
> +		pr_warn("%s: failed to create kworker_fie: %ld\n", __func__,
> +			PTR_ERR(kworker_fie));
> +		fie_disabled = FIE_DISABLED;
>  		return;
> +	}
>  
>  	ret = sched_setattr_nocheck(kworker_fie->task, &attr);
>  	if (ret) {
>  		pr_warn("%s: failed to set SCHED_DEADLINE: %d\n", __func__,
>  			ret);
>  		kthread_destroy_worker(kworker_fie);
> -		return;
> +		fie_disabled = FIE_DISABLED;
>  	}
>  }
>  
> @@ -267,7 +271,6 @@ static void cppc_freq_invariance_exit(void)
>  		return;
>  
>  	kthread_destroy_worker(kworker_fie);
> -	kworker_fie = NULL;
>  }
>  
>  #else

Applied. Thanks.

-- 
viresh