Hi Karthik,
On Fri, Dec 01, 2023 at 08:04:30PM +0530, Karthik Poosa wrote:
> Updated i915 hwmon with fixes for issues reported by static analysis tool.
> Fixed unintentional buffer overflow (OVERFLOW_BEFORE_WIDEN) with upcasting.
what kind of error was this? Was it caught by a static analyzer
or did you actually hit the overflow?
Thanks,
Andi
> Fixes: 4c2572fe0ae7 ("drm/i915/hwmon: Expose power1_max_interval")
> Signed-off-by: Karthik Poosa <karthik.poosa@xxxxxxxxx>
> ---
> 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)
> --
> 2.25.1
