Re: [Patch] UefiCpuPkg PiSmmCpuDxeSmm: Remove unnecessary jmp _SmiHandler

[Laszlo Ersek <lersek@redhat.com>]

On 09/10/18 10:20, Liming Gao wrote:
> This change is wrong introduced by e21e355e2ca7fefb15b4df7078f995d3fb9c2b89
> It is not required. So, revert it.
> 
> Contributed-under: TianoCore Contribution Agreement 1.1
> Signed-off-by: Liming Gao <liming.gao@intel.com>
> Cc: Jiewen Yao <jiewen.yao@intel.com>
> ---
>  UefiCpuPkg/PiSmmCpuDxeSmm/X64/SmiEntry.nasm | 9 ++-------
>  1 file changed, 2 insertions(+), 7 deletions(-)
> 
> diff --git a/UefiCpuPkg/PiSmmCpuDxeSmm/X64/SmiEntry.nasm b/UefiCpuPkg/PiSmmCpuDxeSmm/X64/SmiEntry.nasm
> index 315d0f8..7b1b3ca 100644
> --- a/UefiCpuPkg/PiSmmCpuDxeSmm/X64/SmiEntry.nasm
> +++ b/UefiCpuPkg/PiSmmCpuDxeSmm/X64/SmiEntry.nasm
> @@ -173,9 +173,8 @@ SmiHandlerIdtrAbsAddr:
>      mov     gs, eax
>      mov     ax, [rbx + DSC_SS]
>      mov     ss, eax
> -    mov     rax, strict qword 0         ;   mov     rax, _SmiHandler
> -_SmiHandlerAbsAddr:
> -    jmp     rax
> +
> +;   jmp     _SmiHandler                 ; instruction is not needed
>  
>  _SmiHandler:
>      mov     rbx, [rsp + 0x8]             ; rcx <- CpuIndex
> @@ -229,8 +228,4 @@ ASM_PFX(PiSmmCpuSmiEntryFixupAddress):
>      lea    rax, [ASM_PFX(gSmiHandlerIdtr)]
>      lea    rcx, [SmiHandlerIdtrAbsAddr]
>      mov    qword [rcx - 8], rax
> -
> -    lea    rax, [_SmiHandler]
> -    lea    rcx, [_SmiHandlerAbsAddr]
> -    mov    qword [rcx - 8], rax
>      ret
> 

Please remember to CC package maintainers / reviewers directly.

The patch makes sense to me, and indeed it restores the original code.

Reviewed-by: Laszlo Ersek <lersek@redhat.com>

Can you perhaps add another sentence to the commit message, before you
push the patch, such as "the original code already uses RIP-relative
addressing"?

Thanks
Laszlo