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Subject: Re: [PATCH] cpuidle_set accepts alpha numeric values for idle-set
 operation
To:     Brahadambal Srinivasan <latha@linux.vnet.ibm.com>,
        shuah@kernel.org, trenn@suse.com
Cc:     linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org,
        Shuah Khan <skhan@linuxfoundation.org>
References: <20210105122452.8687-1-latha@linux.vnet.ibm.com>
From:   Shuah Khan <skhan@linuxfoundation.org>
Message-ID: <e2234e38-e18e-e0d3-1a2a-7c8b136d8817@linuxfoundation.org>
Date:   Tue, 5 Jan 2021 11:03:47 -0700
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On 1/5/21 5:24 AM, Brahadambal Srinivasan wrote:
> For both the d and e options in cpuidle_set, an atoi() conversion is
> done without checking if the input argument is all numeric. So, an
> atoi conversion is done on any character provided as input and the
> CPU idle_set operation continues with that integer value, which may
> not be what is intended or entirely correct.
> 
> A similar check is present for cpufreq-set already.
> 
> This patch adds a check to see that the idle_set value is all numeric
> before doing a string-to-int conversion.
> 
> Signed-off-by: Brahadambal Srinivasan <latha@linux.vnet.ibm.com>
> ---
>   tools/power/cpupower/utils/cpuidle-set.c | 39 +++++++++++++++++++++---
>   1 file changed, 34 insertions(+), 5 deletions(-)
> 
> diff --git a/tools/power/cpupower/utils/cpuidle-set.c b/tools/power/cpupower/utils/cpuidle-set.c
> index 46158928f9ad..b3dec48e7141 100644
> --- a/tools/power/cpupower/utils/cpuidle-set.c
> +++ b/tools/power/cpupower/utils/cpuidle-set.c
> @@ -21,6 +21,19 @@ static struct option info_opts[] = {
>        { },
>   };
>   
> +int is_number(char *arg)
> +{
> +	size_t len, i = 0;
> +
> +	len = strlen(arg);
> +
> +	for (i = 0; i < len; i++) {
> +		if (!isdigit(arg[i]))
> +			return 0;
> +	}
> +
> +	return 1;
> +}
>   

Any reason why you can't use isdigit()? Please see isdigit()
usages examples in other tools and cpupower itself.

thanks,
-- Shuah

thanks,
-- Shuah