Re: [PATCH] hwmon: (cros-ec_hwmon) Fix access to restricted __le16

[Thomas Weißschuh]

Thanks!

On 2024-06-06 11:05:07+0000, Guenter Roeck wrote:
> 0-day complains:
> 
> drivers-hwmon-cros_ec_hwmon.c:sparse:sparse:cast-to-restricted-__le16
> 
> Fix by using a __le16 typed variable as parameter to le16_to_cpu().
> 
> Fixes: bc3e45258096 ("hwmon: add ChromeOS EC driver")
> Cc: Thomas Weißschuh <linux@xxxxxxxxxxxxxx>
> Cc: Tzung-Bi Shih <tzungbi@xxxxxxxxxx>
> Signed-off-by: Guenter Roeck <linux@xxxxxxxxxxxx>

Acked-by: Thomas Weißschuh <linux@xxxxxxxxxxxxxx>

Guenter, does sparse work locally for you?

When I run it via "make C=1 drivers/hwmon/cros_ec_hwmon.o" I only get
some random warnings from included headers but nothing of value.

Tzung-Bi, could you pick up this patch through chrome-platform?
(And also "hwmon: (cros_ec) Prevent read overflow in probe()" [0])

[0] https://lore.kernel.org/lkml/42331b70-bd3c-496c-8c79-3ec4faad40b8@moroto.mountain/

> ---
>  drivers/hwmon/cros_ec_hwmon.c | 5 +++--
>  1 file changed, 3 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/hwmon/cros_ec_hwmon.c b/drivers/hwmon/cros_ec_hwmon.c
> index 41f268fa8260..f586987c3502 100644
> --- a/drivers/hwmon/cros_ec_hwmon.c
> +++ b/drivers/hwmon/cros_ec_hwmon.c
> @@ -26,12 +26,13 @@ struct cros_ec_hwmon_priv {
>  static int cros_ec_hwmon_read_fan_speed(struct cros_ec_device *cros_ec, u8 index, u16 *speed)
>  {
>  	int ret;
> +	__le16 __speed;
>  
> -	ret = cros_ec_cmd_readmem(cros_ec, EC_MEMMAP_FAN + index * 2, 2, speed);
> +	ret = cros_ec_cmd_readmem(cros_ec, EC_MEMMAP_FAN + index * 2, 2, &__speed);
>  	if (ret < 0)
>  		return ret;
>  
> -	*speed = le16_to_cpu(*speed);
> +	*speed = le16_to_cpu(__speed);
>  	return 0;
>  }
>  
> -- 
> 2.39.2
>