Re: [PATCH] UefiCpuPkg: Check invalid RegisterCpuFeature parameter

["Ni, Ruiyu" <ruiyu.ni@Intel.com>]

On 12/11/2017 4:16 PM, Song, BinX wrote:
> Check and assert invalid RegisterCpuFeature function parameter
> 
> Cc: Eric Dong <eric.dong@intel.com>
> Cc: Laszlo Ersek <lersek@redhat.com>
> Contributed-under: TianoCore Contribution Agreement 1.1
> Signed-off-by: Bell Song <binx.song@intel.com>
> ---
>   .../Include/Library/RegisterCpuFeaturesLib.h       |  4 ++++
>   .../RegisterCpuFeaturesLib.c                       | 28 ++++++++++++++++++++++
>   2 files changed, 32 insertions(+)
> 
> diff --git a/UefiCpuPkg/Include/Library/RegisterCpuFeaturesLib.h b/UefiCpuPkg/Include/Library/RegisterCpuFeaturesLib.h
> index 9331e49..54244cd 100644
> --- a/UefiCpuPkg/Include/Library/RegisterCpuFeaturesLib.h
> +++ b/UefiCpuPkg/Include/Library/RegisterCpuFeaturesLib.h
> @@ -72,6 +72,10 @@
>   #define CPU_FEATURE_ENERGY_PERFORMANCE_BIAS         (32+10)
>   #define CPU_FEATURE_PPIN                            (32+11)
> +//
> +// When you add new CPU features, please also replace the minor CPU feature
> +// with the max CPU feature in the IsFeatureValidCheck() function.
> +//
>   #define CPU_FEATURE_PROC_TRACE                      (32+12)
> 
>   #define CPU_FEATURE_BEFORE_ALL                      BIT27
>   #define CPU_FEATURE_AFTER_ALL                       BIT28
> diff --git a/UefiCpuPkg/Library/RegisterCpuFeaturesLib/RegisterCpuFeaturesLib.c b/UefiCpuPkg/Library/RegisterCpuFeaturesLib/RegisterCpuFeaturesLib.c
> index dd6a82b..f75d900 100644
> --- a/UefiCpuPkg/Library/RegisterCpuFeaturesLib/RegisterCpuFeaturesLib.c
> +++ b/UefiCpuPkg/Library/RegisterCpuFeaturesLib/RegisterCpuFeaturesLib.c
> @@ -81,6 +81,33 @@ DumpCpuFeature (
>   }
>   
>   /**
> +  Determines if the CPU feature is valid.
> +
> +  @param[in]  Feature        Pointer to CPU feature
> +
> +  @retval TRUE  The CPU feature is valid.
> +  @retval FALSE The CPU feature is invalid.
> +**/
> +BOOLEAN
> +IsFeatureValidCheck (
Can we rename this function name to
"RegisterCpuFeatureLibIsFeatureValid"?


> +  IN UINT32        Feature
> +  )
> +{
> +  UINT32      Data;
> +
> +  Data = Feature;
> +  Data &= ~(CPU_FEATURE_BEFORE | CPU_FEATURE_AFTER | CPU_FEATURE_BEFORE_ALL | CPU_FEATURE_AFTER_ALL);
> +  //
> +  // Please replace CPU feature below with the MAX one if have.
Can we just say "CPU_FEATURE_PROC_TRACE" is the MAX feature we support?


> +  //
> +  if (Data > CPU_FEATURE_PROC_TRACE) {
> +    DEBUG ((DEBUG_ERROR, "Invalid CPU feature: 0x%x ", Feature));
> +    return FALSE;
> +  }
> +  return TRUE;
> +}
> +
> +/**
>     Determines if the feature bit mask is in dependent CPU feature bit mask buffer.
>   
>     @param[in]  FeatureMask        Pointer to CPU feature bit mask
> @@ -444,6 +471,7 @@ RegisterCpuFeature (
>   
>     VA_START (Marker, InitializeFunc);
>     Feature = VA_ARG (Marker, UINT32);
> +  ASSERT (IsFeatureValidCheck(Feature));
>     while (Feature != CPU_FEATURE_END) {
>       ASSERT ((Feature & (CPU_FEATURE_BEFORE | CPU_FEATURE_AFTER))
>                       != (CPU_FEATURE_BEFORE | CPU_FEATURE_AFTER));
> 


-- 
Thanks,
Ray