[Intel-gfx] [PATCH 5/5] drm/i915/dmc: check incoming dmc id validity

[Imre Deak]

On Thu, Feb 02, 2023 at 02:04:52PM +0200, Jani Nikula wrote:
> Add validity checks for the dmc ids computed from pipe parameters in
> intel_dmc_enable_pipe() and intel_dmc_disable_pipe(). It's slightly
> difficult for humans and static analyzers alike to ensure the resulting
> dmc ids are within bounds. Just check them and reject invalid ones.
> 
> Signed-off-by: Jani Nikula <jani.nikula at intel.com>

Patchset looks ok to me:
Reviewed-by: Imre Deak <imre.deak at intel.com>

> ---
>  drivers/gpu/drm/i915/display/intel_dmc.c | 8 ++++++--
>  1 file changed, 6 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/display/intel_dmc.c b/drivers/gpu/drm/i915/display/intel_dmc.c
> index ab0ad8e3e620..3b8e8193d042 100644
> --- a/drivers/gpu/drm/i915/display/intel_dmc.c
> +++ b/drivers/gpu/drm/i915/display/intel_dmc.c
> @@ -415,7 +415,9 @@ static void pipedmc_clock_gating_wa(struct drm_i915_private *i915, bool enable)
>  
>  void intel_dmc_enable_pipe(struct drm_i915_private *i915, enum pipe pipe)
>  {
> -	if (!has_dmc_id_fw(i915, PIPE_TO_DMC_ID(pipe)))
> +	enum intel_dmc_id dmc_id = PIPE_TO_DMC_ID(pipe);
> +
> +	if (!is_valid_dmc_id(dmc_id) || !has_dmc_id_fw(i915, dmc_id))
>  		return;
>  
>  	if (DISPLAY_VER(i915) >= 14)
> @@ -426,7 +428,9 @@ void intel_dmc_enable_pipe(struct drm_i915_private *i915, enum pipe pipe)
>  
>  void intel_dmc_disable_pipe(struct drm_i915_private *i915, enum pipe pipe)
>  {
> -	if (!has_dmc_id_fw(i915, PIPE_TO_DMC_ID(pipe)))
> +	enum intel_dmc_id dmc_id = PIPE_TO_DMC_ID(pipe);
> +
> +	if (!is_valid_dmc_id(dmc_id) || !has_dmc_id_fw(i915, dmc_id))
>  		return;
>  
>  	if (DISPLAY_VER(i915) >= 14)
> -- 
> 2.34.1
>