;------------------------------------------------------------------------------ | |
; | |
; Copyright (c) 2006 - 2022, Intel Corporation. All rights reserved.<BR> | |
; SPDX-License-Identifier: BSD-2-Clause-Patent | |
; | |
; Module Name: | |
; | |
; SetJump.Asm | |
; | |
; Abstract: | |
; | |
; Implementation of SetJump() on IA-32. | |
; | |
;------------------------------------------------------------------------------ | |
%include "Nasm.inc" | |
SECTION .text | |
extern ASM_PFX(InternalAssertJumpBuffer) | |
extern ASM_PFX(PcdGet32 (PcdControlFlowEnforcementPropertyMask)) | |
;------------------------------------------------------------------------------ | |
; UINTN | |
; EFIAPI | |
; SetJump ( | |
; OUT BASE_LIBRARY_JUMP_BUFFER *JumpBuffer | |
; ); | |
;------------------------------------------------------------------------------ | |
global ASM_PFX(SetJump) | |
ASM_PFX(SetJump): | |
push DWORD [esp + 4] | |
call ASM_PFX(InternalAssertJumpBuffer) ; To validate JumpBuffer | |
pop ecx | |
pop ecx ; ecx <- return address | |
mov edx, [esp] | |
xor eax, eax | |
mov [edx + 24], eax ; save 0 to SSP | |
mov eax, [ASM_PFX(PcdGet32 (PcdControlFlowEnforcementPropertyMask))] | |
test eax, eax | |
jz CetDone | |
mov eax, cr4 | |
bt eax, 23 ; check if CET is enabled | |
jnc CetDone | |
mov eax, 1 | |
incsspd eax ; to read original SSP | |
rdsspd eax | |
mov [edx + 0x24], eax ; save SSP | |
CetDone: | |
mov [edx], ebx | |
mov [edx + 4], esi | |
mov [edx + 8], edi | |
mov [edx + 12], ebp | |
mov [edx + 16], esp | |
mov [edx + 20], ecx ; eip value to restore in LongJump | |
xor eax, eax | |
jmp ecx | |