You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
77 lines
2.2 KiB
77 lines
2.2 KiB
/** @file
|
|
Implementation of _LongJump() on IA-32.
|
|
|
|
Copyright (c) 2006 - 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 "BaseLibInternals.h"
|
|
|
|
|
|
/**
|
|
Restores the CPU context that was saved with SetJump().
|
|
|
|
Restores the CPU context from the buffer specified by JumpBuffer.
|
|
This function never returns to the caller.
|
|
Instead is resumes execution based on the state of JumpBuffer.
|
|
|
|
@param JumpBuffer A pointer to CPU context buffer.
|
|
@param Value The value to return when the SetJump() context is restored.
|
|
|
|
**/
|
|
__declspec (naked)
|
|
VOID
|
|
EFIAPI
|
|
InternalLongJump (
|
|
IN BASE_LIBRARY_JUMP_BUFFER *JumpBuffer,
|
|
IN UINTN Value
|
|
)
|
|
{
|
|
_asm {
|
|
mov eax, [PcdGet32 (PcdControlFlowEnforcementPropertyMask)]
|
|
test eax, eax
|
|
jz CetDone
|
|
_emit 0x0F
|
|
_emit 0x20
|
|
_emit 0xE0 ; mov eax, cr4
|
|
bt eax, 23 ; check if CET is enabled
|
|
jnc CetDone
|
|
|
|
mov edx, [esp + 4] ; edx = JumpBuffer
|
|
mov edx, [edx + 24] ; edx = target SSP
|
|
_emit 0xF3
|
|
_emit 0x0F
|
|
_emit 0x1E
|
|
_emit 0xC8 ; READSSP EAX
|
|
sub edx, eax ; edx = delta
|
|
mov eax, edx ; eax = delta
|
|
|
|
shr eax, 2 ; eax = delta/sizeof(UINT32)
|
|
_emit 0xF3
|
|
_emit 0x0F
|
|
_emit 0xAE
|
|
_emit 0xE8 ; INCSSP EAX
|
|
|
|
CetDone:
|
|
|
|
pop eax ; skip return address
|
|
pop edx ; edx <- JumpBuffer
|
|
pop eax ; eax <- Value
|
|
mov ebx, [edx]
|
|
mov esi, [edx + 4]
|
|
mov edi, [edx + 8]
|
|
mov ebp, [edx + 12]
|
|
mov esp, [edx + 16]
|
|
jmp dword ptr [edx + 20]
|
|
}
|
|
}
|
|
|