[edk2-devel] [PATCH v1 1/1] UefiCpuPkg: Clean up save state boundary checks and comments.

[Laszlo Ersek]

Hi Mark,

On 10/15/20 18:32, Mark Wilson wrote:
> REF: https://bugzilla.tianocore.org/show_bug.cgi?id=2956
> 
> In functions ReadSaveStateRegisterByIndex and WriteSaveStateRegister:
> * check width > 4 instead of >= 4 when writing upper 32 bytes.
>   - This improves the code but will not affect functionality.
> * Update related comments to better describe code.
> 
> Cc: Eric Dong <eric.dong at intel.com>
> Cc: Ray Ni <ray.ni at intel.com>
> Signed-off-by: Mark Wilson <Mark.Wilson at amd.com>
> ---
>  UefiCpuPkg/PiSmmCpuDxeSmm/SmramSaveState.c | 26 ++++++++++----------
>  1 file changed, 13 insertions(+), 13 deletions(-)

I suggest separating the cosmetic changes (such as the whitespace fixes)
from the cleanups (comments etc) to different patches.

Also, please run "BaseTools/Scripts/SetupGit.py" in your edk2 clone.

Thanks,
Laszlo

> 
> diff --git a/UefiCpuPkg/PiSmmCpuDxeSmm/SmramSaveState.c b/UefiCpuPkg/PiSmmCpuDxeSmm/SmramSaveState.c
> index 661cc51f361a..4a872e400b7a 100644
> --- a/UefiCpuPkg/PiSmmCpuDxeSmm/SmramSaveState.c
> +++ b/UefiCpuPkg/PiSmmCpuDxeSmm/SmramSaveState.c
> @@ -297,8 +297,8 @@ ReadSaveStateRegisterByIndex (
>      //
> 
>      // Write return buffer
> 
>      //
> 
> -    ASSERT(CpuSaveState != NULL);
> 
> -    CopyMem(Buffer, (UINT8 *)CpuSaveState + mSmmCpuWidthOffset[RegisterIndex].Offset32, Width);
> 
> +    ASSERT (CpuSaveState != NULL);
> 
> +    CopyMem (Buffer, (UINT8 *)CpuSaveState + mSmmCpuWidthOffset[RegisterIndex].Offset32, Width);
> 
>    } else {
> 
>      //
> 
>      // If 64-bit mode width is zero, then the specified register can not be accessed
> 
> @@ -315,14 +315,14 @@ ReadSaveStateRegisterByIndex (
>      }
> 
>  
> 
>      //
> 
> -    // Write lower 32-bits of return buffer
> 
> +    // Write at most 4 of the lower bytes of the return buffer
> 
>      //
> 
> -    CopyMem(Buffer, (UINT8 *)CpuSaveState + mSmmCpuWidthOffset[RegisterIndex].Offset64Lo, MIN(4, Width));
> 
> -    if (Width >= 4) {
> 
> +    CopyMem (Buffer, (UINT8 *)CpuSaveState + mSmmCpuWidthOffset[RegisterIndex].Offset64Lo, MIN(4, Width));
> 
> +    if (Width > 4) {
> 
>        //
> 
> -      // Write upper 32-bits of return buffer
> 
> +      // Write at most 4 of the upper bytes of the return buffer
> 
>        //
> 
> -      CopyMem((UINT8 *)Buffer + 4, (UINT8 *)CpuSaveState + mSmmCpuWidthOffset[RegisterIndex].Offset64Hi, Width - 4);
> 
> +      CopyMem ((UINT8 *)Buffer + 4, (UINT8 *)CpuSaveState + mSmmCpuWidthOffset[RegisterIndex].Offset64Hi, Width - 4);
> 
>      }
> 
>    }
> 
>    return EFI_SUCCESS;
> 
> @@ -522,7 +522,7 @@ WriteSaveStateRegister (
>      // Write SMM State register
> 
>      //
> 
>      ASSERT (CpuSaveState != NULL);
> 
> -    CopyMem((UINT8 *)CpuSaveState + mSmmCpuWidthOffset[RegisterIndex].Offset32, Buffer, Width);
> 
> +    CopyMem ((UINT8 *)CpuSaveState + mSmmCpuWidthOffset[RegisterIndex].Offset32, Buffer, Width);
> 
>    } else {
> 
>      //
> 
>      // If 64-bit mode width is zero, then the specified register can not be accessed
> 
> @@ -539,14 +539,14 @@ WriteSaveStateRegister (
>      }
> 
>  
> 
>      //
> 
> -    // Write lower 32-bits of SMM State register
> 
> +    // Write at most 4 of the lower bytes of SMM State register
> 
>      //
> 
> -    CopyMem((UINT8 *)CpuSaveState + mSmmCpuWidthOffset[RegisterIndex].Offset64Lo, Buffer, MIN (4, Width));
> 
> -    if (Width >= 4) {
> 
> +    CopyMem ((UINT8 *)CpuSaveState + mSmmCpuWidthOffset[RegisterIndex].Offset64Lo, Buffer, MIN (4, Width));
> 
> +    if (Width > 4) {
> 
>        //
> 
> -      // Write upper 32-bits of SMM State register
> 
> +      // Write at most 4 of the upper bytes of SMM State register
> 
>        //
> 
> -      CopyMem((UINT8 *)CpuSaveState + mSmmCpuWidthOffset[RegisterIndex].Offset64Hi, (UINT8 *)Buffer + 4, Width - 4);
> 
> +      CopyMem ((UINT8 *)CpuSaveState + mSmmCpuWidthOffset[RegisterIndex].Offset64Hi, (UINT8 *)Buffer + 4, Width - 4);
> 
>      }
> 
>    }
> 
>    return EFI_SUCCESS;
> 



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