audk/UefiCpuPkg/PiSmmCpuDxeSmm/X64/Cet.nasm

41 lines
1.1 KiB
NASM

;------------------------------------------------------------------------------ ;
; Copyright (c) 2019, Intel Corporation. All rights reserved.<BR>
; This program and the accompanying materials
; are licensed and made available under the terms and conditions of the BSD License
; which accompanies this distribution. The full text of the license may be found at
; http://opensource.org/licenses/bsd-license.php.
;
; THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
; WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
;
;-------------------------------------------------------------------------------
%include "Nasm.inc"
DEFAULT REL
SECTION .text
global ASM_PFX(DisableCet)
ASM_PFX(DisableCet):
; Skip the pushed data for call
mov rax, 1
INCSSP_RAX
mov rax, cr4
btr eax, 23 ; clear CET
mov cr4, rax
ret
global ASM_PFX(EnableCet)
ASM_PFX(EnableCet):
mov rax, cr4
bts eax, 23 ; set CET
mov cr4, rax
; use jmp to skip the check for ret
pop rax
jmp rax