Re: [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 
---
  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)

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

[Gupta, Anshuman]

> -Original Message-
> From: Poosa, Karthik 
> Sent: Friday, December 1, 2023 10:28 AM
> To: intel-gfx@lists.freedesktop.org
> Cc: Gupta, Anshuman ; Nilawar, Badal
> ; Poosa, Karthik 
> Subject: [PATCH] drm/i915/hwmon: Fix static analysis tool errors in i915
> hwmon
> 
> 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].
> 
> Signed-off-by: Karthik Poosa 
Reviewed-by: Anshuman Gupta 

> ---
>  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

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

[Jani Nikula]

On Wed, 29 Nov 2023, Karthik Poosa  wrote:
> Updated i915 hwmon with fixes for issues reported by static analysis tool.

What's the problem? It's not enough to say this fixes a static analyzer
report. Tell us what the problem is, and why this is the fix.

BR,
Jani.


>
> Signed-off-by: Karthik Poosa 
> ---
>  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..69bb49a684b6 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)

-- 
Jani Nikula, Intel