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;------------------------------------------------------------------------------
;
; 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
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