[Intel-gfx] [PATCH] drm/i915/hwmon: Fix static analysis tool errors in i915 hwmon

[Nilawar, Badal]

Hi Karthik,

On 01-12-2023 10:28, Karthik Poosa wrote:
> Updated i915 hwmon with fixes for issues reported by static analysis tool.
> Fixed unintentional buffer overflow (OVERFLOW_BEFORE_WIDEN) with upcasting.
> 
> v2: Updated commit message with details of issue [Jani].
Please add fixes tag.
Fixes: 4c2572fe0ae7 ("drm/i915/hwmon: Expose power1_max_interval")

Regards,
Badal
> 
> Signed-off-by: Karthik Poosa <karthik.poosa at intel.com>
> ---
>   drivers/gpu/drm/i915/i915_hwmon.c | 4 ++--
>   1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/i915_hwmon.c b/drivers/gpu/drm/i915/i915_hwmon.c
> index 975da8e7f2a9..8c3f443c8347 100644
> --- a/drivers/gpu/drm/i915/i915_hwmon.c
> +++ b/drivers/gpu/drm/i915/i915_hwmon.c
> @@ -175,7 +175,7 @@ hwm_power1_max_interval_show(struct device *dev, struct device_attribute *attr,
>   	 *     tau4 = (4 | x) << y
>   	 * but add 2 when doing the final right shift to account for units
>   	 */
> -	tau4 = ((1 << x_w) | x) << y;
> +	tau4 = (u64)((1 << x_w) | x) << y;
>   	/* val in hwmon interface units (millisec) */
>   	out = mul_u64_u32_shr(tau4, SF_TIME, hwmon->scl_shift_time + x_w);
>   
> @@ -211,7 +211,7 @@ hwm_power1_max_interval_store(struct device *dev,
>   	r = FIELD_PREP(PKG_MAX_WIN, PKG_MAX_WIN_DEFAULT);
>   	x = REG_FIELD_GET(PKG_MAX_WIN_X, r);
>   	y = REG_FIELD_GET(PKG_MAX_WIN_Y, r);
> -	tau4 = ((1 << x_w) | x) << y;
> +	tau4 = (u64)((1 << x_w) | x) << y;
>   	max_win = mul_u64_u32_shr(tau4, SF_TIME, hwmon->scl_shift_time + x_w);
>   
>   	if (val > max_win)