On 12/13/17 03:35, Song, BinX wrote: > V2: > Update function name, add more detail description. > V1: > Check and assert invalid RegisterCpuFeature function parameter > > Cc: Eric Dong <[email protected]> > Cc: Laszlo Ersek <[email protected]> > Contributed-under: TianoCore Contribution Agreement 1.1 > Signed-off-by: Bell Song <[email protected]> > --- > .../Include/Library/RegisterCpuFeaturesLib.h | 5 ++++ > .../RegisterCpuFeaturesLib.c | 29 > ++++++++++++++++++++++ > 2 files changed, 34 insertions(+) > > diff --git a/UefiCpuPkg/Include/Library/RegisterCpuFeaturesLib.h > b/UefiCpuPkg/Include/Library/RegisterCpuFeaturesLib.h > index 9331e49..fc3ccda 100644 > --- a/UefiCpuPkg/Include/Library/RegisterCpuFeaturesLib.h > +++ b/UefiCpuPkg/Include/Library/RegisterCpuFeaturesLib.h > @@ -71,6 +71,11 @@ > #define CPU_FEATURE_APIC_TPR_UPDATE_MESSAGE (32+9) > #define CPU_FEATURE_ENERGY_PERFORMANCE_BIAS (32+10) > #define CPU_FEATURE_PPIN (32+11) > +// > +// Currently, CPU_FEATURE_PROC_TRACE is the MAX feature we support. > +// If you define a feature bigger than it, please also replace it > +// in RegisterCpuFeatureLibIsFeatureValid function. > +// > #define CPU_FEATURE_PROC_TRACE (32+12) > > #define CPU_FEATURE_BEFORE_ALL BIT27 > diff --git > a/UefiCpuPkg/Library/RegisterCpuFeaturesLib/RegisterCpuFeaturesLib.c > b/UefiCpuPkg/Library/RegisterCpuFeaturesLib/RegisterCpuFeaturesLib.c > index dd6a82b..6ec26e1 100644 > --- a/UefiCpuPkg/Library/RegisterCpuFeaturesLib/RegisterCpuFeaturesLib.c > +++ b/UefiCpuPkg/Library/RegisterCpuFeaturesLib/RegisterCpuFeaturesLib.c > @@ -81,6 +81,34 @@ 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 > +RegisterCpuFeatureLibIsFeatureValid ( > + IN UINT32 Feature > + ) > +{ > + UINT32 Data; > + > + Data = Feature; > + Data &= ~(CPU_FEATURE_BEFORE | CPU_FEATURE_AFTER | CPU_FEATURE_BEFORE_ALL > | CPU_FEATURE_AFTER_ALL); > + // > + // Currently, CPU_FEATURE_PROC_TRACE is the MAX feature we support. > + // If you define a feature bigger than it, please replace it at below. > + // > + 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 +472,7 @@ RegisterCpuFeature ( > > VA_START (Marker, InitializeFunc); > Feature = VA_ARG (Marker, UINT32); > + ASSERT (RegisterCpuFeatureLibIsFeatureValid(Feature)); > while (Feature != CPU_FEATURE_END) { > ASSERT ((Feature & (CPU_FEATURE_BEFORE | CPU_FEATURE_AFTER)) > != (CPU_FEATURE_BEFORE | CPU_FEATURE_AFTER)); >
The consensus thus far seems to be that we should not add a separate _MAX macro for this purpose. I don't understand why -- in my opinion it would be easier to update the macro in one place only. Now, I realize we have a library class header file here, and a library instance. Those things are separate; it is conceivable that another library instance is developed independently, and thus we should not tie the MAX feature of *all* library instances to the same central class header. However, this separation is already being violated in this patch: the RegisterCpuFeatureLibIsFeatureValid() function is an implementation detail of the (currently only one) library instance. Thus, the lib class header should not refer to it, even in a comment. So, I don't understand why we can't just add a _MAX macro. The central library instance could use _MAX; all other (out of tree) instances would not use _MAX. Anyway, this doesn't mean the patch is not correct. Acked-by: Laszlo Ersek <[email protected]> Thanks Laszlo _______________________________________________ edk2-devel mailing list [email protected] https://lists.01.org/mailman/listinfo/edk2-devel
