audk/UefiCpuPkg/PiSmmCpuDxeSmm/Ia32/Cet.nasm

34 lines
786 B
NASM

;------------------------------------------------------------------------------ ;
; Copyright (c) 2019, Intel Corporation. All rights reserved.<BR>
; SPDX-License-Identifier: BSD-2-Clause-Patent
;
;-------------------------------------------------------------------------------
%include "Nasm.inc"
SECTION .text
global ASM_PFX(DisableCet)
ASM_PFX(DisableCet):
; Skip the pushed data for call
mov eax, 1
INCSSP_EAX
mov eax, cr4
btr eax, 23 ; clear CET
mov cr4, eax
ret
global ASM_PFX(EnableCet)
ASM_PFX(EnableCet):
mov eax, cr4
bts eax, 23 ; set CET
mov cr4, eax
; use jmp to skip the check for ret
pop eax
jmp eax