Re: [PATCH v12 15/19] tpm, tpm_tis: Address positive localities in tpm_tis_request_locality()

[Jarkko Sakkinen]

On Thu, Dec 19, 2024 at 11:42:12AM -0800, Ross Philipson wrote:
> From: "Daniel P. Smith" <dpsmith@xxxxxxxxxxxxxxxxxxxx>
> 
> Validate that the input locality is within the correct range, as specified
> by TCG standards, and increase the locality count also for the positive
> localities.
> 
> Signed-off-by: Daniel P. Smith <dpsmith@xxxxxxxxxxxxxxxxxxxx>
> Signed-off-by: Ross Philipson <ross.philipson@xxxxxxxxxx>
> Signed-off-by: Jarkko Sakkinen <jarkko@xxxxxxxxxx>
> ---
>  drivers/char/tpm/tpm_tis_core.c | 5 ++++-
>  1 file changed, 4 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/char/tpm/tpm_tis_core.c b/drivers/char/tpm/tpm_tis_core.c
> index c58f360fb4a4..c86100ad743a 100644
> --- a/drivers/char/tpm/tpm_tis_core.c
> +++ b/drivers/char/tpm/tpm_tis_core.c
> @@ -234,10 +234,13 @@ static int tpm_tis_request_locality(struct tpm_chip *chip, int l)
>  	struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
>  	int ret = 0;
>  
> +	if (l < 0 || l > TPM_MAX_LOCALITY)
> +		return -EINVAL;

I would mind if we put do dev_warn() here because it is unexpected
condition or even perhaps dev_err(). Or am I missing something?

> +
>  	mutex_lock(&priv->locality_count_mutex);
>  	if (priv->locality_count == 0)
>  		ret = __tpm_tis_request_locality(chip, l);
> -	if (!ret)
> +	if (ret >= 0)
>  		priv->locality_count++;
>  	mutex_unlock(&priv->locality_count_mutex);
>  	return ret;
> -- 
> 2.39.3
> 

I agree with this now.

BR, Jarkko