Re: [PATCH] UefiCpuPkg: Check invalid RegisterCpuFeature parameter

["Song, BinX" <binx.song@intel.com>]

Hi Ray,

Got it, I will update a V2 patch.

Best Regards,
Bell Song

> -----Original Message-----
> From: Ni, Ruiyu
> Sent: Tuesday, December 12, 2017 4:44 PM
> To: Song, BinX <binx.song@intel.com>; edk2-devel@lists.01.org
> Cc: lersek@redhat.com; Dong, Eric <eric.dong@intel.com>
> Subject: RE: [edk2] [PATCH] UefiCpuPkg: Check invalid RegisterCpuFeature
> parameter
> 
> > -----Original Message-----
> > From: Song, BinX
> > Sent: Monday, December 11, 2017 6:00 PM
> > To: Ni, Ruiyu <ruiyu.ni@intel.com>; edk2-devel@lists.01.org
> > Cc: lersek@redhat.com; Dong, Eric <eric.dong@intel.com>
> > Subject: RE: [edk2] [PATCH] UefiCpuPkg: Check invalid RegisterCpuFeature
> > parameter
> >
> > Hi Ray,
> >
> > Below is my opinions for your 2 questions:
> > 1. Can we rename this function name to
> > "RegisterCpuFeatureLibIsFeatureValid"?
> > [Bell]: In content of RegisterCpuFeaturesLib.c, there is a function named
> > IsBitMaskMatchCheck(), it's my function's base, they have similar function -
> a
> > small valid/invalid check, So I think it is better to keep them align.
> The original function name IsXXXXCheck() is not good. Please do not follow
> the
> same naming style.
> 
> > 2. Can we just say "CPU_FEATURE_PROC_TRACE" is the MAX feature we
> > support?
> > [Bell]: Discussed with Eric before, we should not define this as a MAX
> feature
> > for future extension purpose.
> I didn't mean to define a new MAX macro.
> You just need to update the comments.
> >
> > Best Regards,
> > Bell Song
> >
> >
> > > -----Original Message-----
> > > From: Ni, Ruiyu
> > > Sent: Monday, December 11, 2017 5:40 PM
> > > To: Song, BinX <binx.song@intel.com>; edk2-devel@lists.01.org
> > > Cc: lersek@redhat.com; Dong, Eric <eric.dong@intel.com>
> > > Subject: Re: [edk2] [PATCH] UefiCpuPkg: Check invalid
> > > RegisterCpuFeature parameter
> > >
> > > 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