Re: [PATCH] tpm/ppi: fix return type in tpm_show_ppi_response()

[Jarkko Sakkinen <jarkko@kernel.org>]

On Thu, Aug 04, 2022 at 10:07:42AM +0300, Dan Carpenter wrote:
> This "status" is declared as type acpi_status but it is never used to
> store any acpi_statuses, only int.
> 
> The tpm_show_ppi_response() function returns ssize_t (signed long) and
> acpi_status is unsigned int.  That means that negative error codes will
> be type promoted to large positive values.
> 
> Fixes: 84b1667dea23 ("ACPI / TPM: replace open-coded _DSM code with helper functions")
> Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
> ---
>  drivers/char/tpm/tpm_ppi.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/char/tpm/tpm_ppi.c b/drivers/char/tpm/tpm_ppi.c
> index 40018a73b3cb..240df925c38c 100644
> --- a/drivers/char/tpm/tpm_ppi.c
> +++ b/drivers/char/tpm/tpm_ppi.c
> @@ -222,7 +222,7 @@ static ssize_t tpm_show_ppi_response(struct device *dev,
>  				     struct device_attribute *attr,
>  				     char *buf)
>  {
> -	acpi_status status = -EINVAL;
> +	int status = -EINVAL;
>  	union acpi_object *obj, *ret_obj;
>  	u64 req, res;
>  	struct tpm_chip *chip = to_tpm_chip(dev);
> -- 
> 2.35.1
> 


Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org>

BR, Jarkko