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|
;------------------------------------------------------------------------------ ;
; Copyright (c) 2009 - 2019, Intel Corporation. All rights reserved.<BR>
; SPDX-License-Identifier: BSD-2-Clause-Patent
;
; Module Name:
;
; SmiException.nasm
;
; Abstract:
;
; Exception handlers used in SM mode
;
;-------------------------------------------------------------------------------
extern ASM_PFX(FeaturePcdGet (PcdCpuSmmProfileEnable))
extern ASM_PFX(SmiPFHandler)
extern ASM_PFX(mSetupDebugTrap)
global ASM_PFX(gcSmiIdtr)
global ASM_PFX(gcSmiGdtr)
global ASM_PFX(gTaskGateDescriptor)
global ASM_PFX(gcPsd)
SECTION .data
NullSeg: DQ 0 ; reserved by architecture
CodeSeg32:
DW -1 ; LimitLow
DW 0 ; BaseLow
DB 0 ; BaseMid
DB 0x9b
DB 0xcf ; LimitHigh
DB 0 ; BaseHigh
ProtModeCodeSeg32:
DW -1 ; LimitLow
DW 0 ; BaseLow
DB 0 ; BaseMid
DB 0x9b
DB 0xcf ; LimitHigh
DB 0 ; BaseHigh
ProtModeSsSeg32:
DW -1 ; LimitLow
DW 0 ; BaseLow
DB 0 ; BaseMid
DB 0x93
DB 0xcf ; LimitHigh
DB 0 ; BaseHigh
DataSeg32:
DW -1 ; LimitLow
DW 0 ; BaseLow
DB 0 ; BaseMid
DB 0x93
DB 0xcf ; LimitHigh
DB 0 ; BaseHigh
CodeSeg16:
DW -1
DW 0
DB 0
DB 0x9b
DB 0x8f
DB 0
DataSeg16:
DW -1
DW 0
DB 0
DB 0x93
DB 0x8f
DB 0
CodeSeg64:
DW -1 ; LimitLow
DW 0 ; BaseLow
DB 0 ; BaseMid
DB 0x9b
DB 0xaf ; LimitHigh
DB 0 ; BaseHigh
GDT_SIZE equ $ - NullSeg
TssSeg:
DW TSS_DESC_SIZE ; LimitLow
DW 0 ; BaseLow
DB 0 ; BaseMid
DB 0x89
DB 0x80 ; LimitHigh
DB 0 ; BaseHigh
ExceptionTssSeg:
DW EXCEPTION_TSS_DESC_SIZE ; LimitLow
DW 0 ; BaseLow
DB 0 ; BaseMid
DB 0x89
DB 0x80 ; LimitHigh
DB 0 ; BaseHigh
CODE_SEL equ CodeSeg32 - NullSeg
DATA_SEL equ DataSeg32 - NullSeg
TSS_SEL equ TssSeg - NullSeg
EXCEPTION_TSS_SEL equ ExceptionTssSeg - NullSeg
struc IA32_TSS
resw 1
resw 1
.ESP0: resd 1
.SS0: resw 1
resw 1
.ESP1: resd 1
.SS1: resw 1
resw 1
.ESP2: resd 1
.SS2: resw 1
resw 1
._CR3: resd 1
.EIP: resd 1
.EFLAGS: resd 1
._EAX: resd 1
._ECX: resd 1
._EDX: resd 1
._EBX: resd 1
._ESP: resd 1
._EBP: resd 1
._ESI: resd 1
._EDI: resd 1
._ES: resw 1
resw 1
._CS: resw 1
resw 1
._SS: resw 1
resw 1
._DS: resw 1
resw 1
._FS: resw 1
resw 1
._GS: resw 1
resw 1
.LDT: resw 1
resw 1
resw 1
resw 1
endstruc
; Create 2 TSS segments just after GDT
TssDescriptor:
DW 0 ; PreviousTaskLink
DW 0 ; Reserved
DD 0 ; ESP0
DW 0 ; SS0
DW 0 ; Reserved
DD 0 ; ESP1
DW 0 ; SS1
DW 0 ; Reserved
DD 0 ; ESP2
DW 0 ; SS2
DW 0 ; Reserved
DD 0 ; CR3
DD 0 ; EIP
DD 0 ; EFLAGS
DD 0 ; EAX
DD 0 ; ECX
DD 0 ; EDX
DD 0 ; EBX
DD 0 ; ESP
DD 0 ; EBP
DD 0 ; ESI
DD 0 ; EDI
DW 0 ; ES
DW 0 ; Reserved
DW 0 ; CS
DW 0 ; Reserved
DW 0 ; SS
DW 0 ; Reserved
DW 0 ; DS
DW 0 ; Reserved
DW 0 ; FS
DW 0 ; Reserved
DW 0 ; GS
DW 0 ; Reserved
DW 0 ; LDT Selector
DW 0 ; Reserved
DW 0 ; T
DW 0 ; I/O Map Base
TSS_DESC_SIZE equ $ - TssDescriptor
ExceptionTssDescriptor:
DW 0 ; PreviousTaskLink
DW 0 ; Reserved
DD 0 ; ESP0
DW 0 ; SS0
DW 0 ; Reserved
DD 0 ; ESP1
DW 0 ; SS1
DW 0 ; Reserved
DD 0 ; ESP2
DW 0 ; SS2
DW 0 ; Reserved
DD 0 ; CR3
DD PFHandlerEntry ; EIP
DD 00000002 ; EFLAGS
DD 0 ; EAX
DD 0 ; ECX
DD 0 ; EDX
DD 0 ; EBX
DD 0 ; ESP
DD 0 ; EBP
DD 0 ; ESI
DD 0 ; EDI
DW DATA_SEL ; ES
DW 0 ; Reserved
DW CODE_SEL ; CS
DW 0 ; Reserved
DW DATA_SEL ; SS
DW 0 ; Reserved
DW DATA_SEL ; DS
DW 0 ; Reserved
DW DATA_SEL ; FS
DW 0 ; Reserved
DW DATA_SEL ; GS
DW 0 ; Reserved
DW 0 ; LDT Selector
DW 0 ; Reserved
DW 0 ; T
DW 0 ; I/O Map Base
DD 0 ; SSP
EXCEPTION_TSS_DESC_SIZE equ $ - ExceptionTssDescriptor
ASM_PFX(gcPsd):
DB 'PSDSIG '
DW PSD_SIZE
DW 2
DW 1 << 2
DW CODE_SEL
DW DATA_SEL
DW DATA_SEL
DW DATA_SEL
DW 0
DQ 0
DQ 0
DQ 0
DD 0
DD NullSeg
DD GDT_SIZE
DD 0
times 24 DB 0
DD 0
DD 0
PSD_SIZE equ $ - ASM_PFX(gcPsd)
ASM_PFX(gcSmiGdtr):
DW GDT_SIZE - 1
DD NullSeg
ASM_PFX(gcSmiIdtr):
DW 0
DD 0
ASM_PFX(gTaskGateDescriptor):
DW 0 ; Reserved
DW EXCEPTION_TSS_SEL ; TSS Segment selector
DB 0 ; Reserved
DB 0x85 ; Task Gate, present, DPL = 0
DW 0 ; Reserved
SECTION .text
;------------------------------------------------------------------------------
; PageFaultIdtHandlerSmmProfile is the entry point page fault only
;
;
; Stack:
; +---------------------+
; + EFlags +
; +---------------------+
; + CS +
; +---------------------+
; + EIP +
; +---------------------+
; + Error Code +
; +---------------------+
; + Vector Number +
; +---------------------+
; + EBP +
; +---------------------+ <-- EBP
;
;
;------------------------------------------------------------------------------
global ASM_PFX(PageFaultIdtHandlerSmmProfile)
ASM_PFX(PageFaultIdtHandlerSmmProfile):
push 0xe ; Page Fault
push ebp
mov ebp, esp
;
; Align stack to make sure that EFI_FX_SAVE_STATE_IA32 of EFI_SYSTEM_CONTEXT_IA32
; is 16-byte aligned
;
and esp, 0xfffffff0
sub esp, 12
;; UINT32 Edi, Esi, Ebp, Esp, Ebx, Edx, Ecx, Eax;
push eax
push ecx
push edx
push ebx
lea ecx, [ebp + 6 * 4]
push ecx ; ESP
push dword [ebp] ; EBP
push esi
push edi
;; UINT32 Gs, Fs, Es, Ds, Cs, Ss;
mov eax, ss
push eax
movzx eax, word [ebp + 4 * 4]
push eax
mov eax, ds
push eax
mov eax, es
push eax
mov eax, fs
push eax
mov eax, gs
push eax
;; UINT32 Eip;
mov eax, [ebp + 3 * 4]
push eax
;; UINT32 Gdtr[2], Idtr[2];
sub esp, 8
sidt [esp]
mov eax, [esp + 2]
xchg eax, [esp]
and eax, 0xFFFF
mov [esp+4], eax
sub esp, 8
sgdt [esp]
mov eax, [esp + 2]
xchg eax, [esp]
and eax, 0xFFFF
mov [esp+4], eax
;; UINT32 Ldtr, Tr;
xor eax, eax
str ax
push eax
sldt ax
push eax
;; UINT32 EFlags;
mov eax, [ebp + 5 * 4]
push eax
;; UINT32 Cr0, Cr1, Cr2, Cr3, Cr4;
mov eax, cr4
or eax, 0x208
mov cr4, eax
push eax
mov eax, cr3
push eax
mov eax, cr2
push eax
xor eax, eax
push eax
mov eax, cr0
push eax
;; UINT32 Dr0, Dr1, Dr2, Dr3, Dr6, Dr7;
mov eax, dr7
push eax
mov eax, dr6
push eax
mov eax, dr3
push eax
mov eax, dr2
push eax
mov eax, dr1
push eax
mov eax, dr0
push eax
;; FX_SAVE_STATE_IA32 FxSaveState;
sub esp, 512
mov edi, esp
fxsave [edi]
; UEFI calling convention for IA32 requires that Direction flag in EFLAGs is clear
cld
;; UINT32 ExceptionData;
push dword [ebp + 2 * 4]
;; call into exception handler
;; Prepare parameter and call
mov edx, esp
push edx
mov edx, dword [ebp + 1 * 4]
push edx
;
; Call External Exception Handler
;
mov eax, ASM_PFX(SmiPFHandler)
call eax
add esp, 8
;; UINT32 ExceptionData;
add esp, 4
;; FX_SAVE_STATE_IA32 FxSaveState;
mov esi, esp
fxrstor [esi]
add esp, 512
;; UINT32 Dr0, Dr1, Dr2, Dr3, Dr6, Dr7;
;; Skip restoration of DRx registers to support debuggers
;; that set breakpoint in interrupt/exception context
add esp, 4 * 6
;; UINT32 Cr0, Cr1, Cr2, Cr3, Cr4;
pop eax
mov cr0, eax
add esp, 4 ; not for Cr1
pop eax
mov cr2, eax
pop eax
mov cr3, eax
pop eax
mov cr4, eax
;; UINT32 EFlags;
pop dword [ebp + 5 * 4]
;; UINT32 Ldtr, Tr;
;; UINT32 Gdtr[2], Idtr[2];
;; Best not let anyone mess with these particular registers...
add esp, 24
;; UINT32 Eip;
pop dword [ebp + 3 * 4]
;; UINT32 Gs, Fs, Es, Ds, Cs, Ss;
;; NOTE - modified segment registers could hang the debugger... We
;; could attempt to insulate ourselves against this possibility,
;; but that poses risks as well.
;;
pop gs
pop fs
pop es
pop ds
pop dword [ebp + 4 * 4]
pop ss
;; UINT32 Edi, Esi, Ebp, Esp, Ebx, Edx, Ecx, Eax;
pop edi
pop esi
add esp, 4 ; not for ebp
add esp, 4 ; not for esp
pop ebx
pop edx
pop ecx
pop eax
mov esp, ebp
pop ebp
; Enable TF bit after page fault handler runs
bts dword [esp + 16], 8 ; EFLAGS
add esp, 8 ; skip INT# & ErrCode
Return:
iretd
;
; Page Fault Exception Handler entry when SMM Stack Guard is enabled
; Executiot starts here after a task switch
;
PFHandlerEntry:
;
; Get this processor's TSS
;
sub esp, 8
sgdt [esp + 2]
mov eax, [esp + 4] ; GDT base
add esp, 8
mov ecx, [eax + TSS_SEL + 2]
shl ecx, 8
mov cl, [eax + TSS_SEL + 7]
ror ecx, 8 ; ecx = TSS base
mov ebp, esp
;
; Align stack to make sure that EFI_FX_SAVE_STATE_IA32 of EFI_SYSTEM_CONTEXT_IA32
; is 16-byte aligned
;
and esp, 0xfffffff0
sub esp, 12
;; UINT32 Edi, Esi, Ebp, Esp, Ebx, Edx, Ecx, Eax;
push dword [ecx + IA32_TSS._EAX]
push dword [ecx + IA32_TSS._ECX]
push dword [ecx + IA32_TSS._EDX]
push dword [ecx + IA32_TSS._EBX]
push dword [ecx + IA32_TSS._ESP]
push dword [ecx + IA32_TSS._EBP]
push dword [ecx + IA32_TSS._ESI]
push dword [ecx + IA32_TSS._EDI]
;; UINT32 Gs, Fs, Es, Ds, Cs, Ss;
movzx eax, word [ecx + IA32_TSS._SS]
push eax
movzx eax, word [ecx + IA32_TSS._CS]
push eax
movzx eax, word [ecx + IA32_TSS._DS]
push eax
movzx eax, word [ecx + IA32_TSS._ES]
push eax
movzx eax, word [ecx + IA32_TSS._FS]
push eax
movzx eax, word [ecx + IA32_TSS._GS]
push eax
;; UINT32 Eip;
push dword [ecx + IA32_TSS.EIP]
;; UINT32 Gdtr[2], Idtr[2];
sub esp, 8
sidt [esp]
mov eax, [esp + 2]
xchg eax, [esp]
and eax, 0xFFFF
mov [esp+4], eax
sub esp, 8
sgdt [esp]
mov eax, [esp + 2]
xchg eax, [esp]
and eax, 0xFFFF
mov [esp+4], eax
;; UINT32 Ldtr, Tr;
mov eax, TSS_SEL
push eax
movzx eax, word [ecx + IA32_TSS.LDT]
push eax
;; UINT32 EFlags;
push dword [ecx + IA32_TSS.EFLAGS]
;; UINT32 Cr0, Cr1, Cr2, Cr3, Cr4;
mov eax, cr4
or eax, 0x208
mov cr4, eax
push eax
mov eax, cr3
push eax
mov eax, cr2
push eax
xor eax, eax
push eax
mov eax, cr0
push eax
;; UINT32 Dr0, Dr1, Dr2, Dr3, Dr6, Dr7;
mov eax, dr7
push eax
mov eax, dr6
push eax
mov eax, dr3
push eax
mov eax, dr2
push eax
mov eax, dr1
push eax
mov eax, dr0
push eax
;; FX_SAVE_STATE_IA32 FxSaveState;
;; Clear TS bit in CR0 to avoid Device Not Available Exception (#NM)
;; when executing fxsave/fxrstor instruction
clts
sub esp, 512
mov edi, esp
fxsave [edi]
; UEFI calling convention for IA32 requires that Direction flag in EFLAGs is clear
cld
;; UINT32 ExceptionData;
push dword [ebp]
;; call into exception handler
mov ebx, ecx
mov eax, ASM_PFX(SmiPFHandler)
;; Prepare parameter and call
mov edx, esp
push edx
mov edx, 14
push edx
;
; Call External Exception Handler
;
call eax
add esp, 8
mov ecx, ebx
;; UINT32 ExceptionData;
add esp, 4
;; FX_SAVE_STATE_IA32 FxSaveState;
mov esi, esp
fxrstor [esi]
add esp, 512
;; UINT32 Dr0, Dr1, Dr2, Dr3, Dr6, Dr7;
;; Skip restoration of DRx registers to support debuggers
;; that set breakpoints in interrupt/exception context
add esp, 4 * 6
;; UINT32 Cr0, Cr1, Cr2, Cr3, Cr4;
pop eax
mov cr0, eax
add esp, 4 ; not for Cr1
pop eax
mov cr2, eax
pop eax
mov dword [ecx + IA32_TSS._CR3], eax
pop eax
mov cr4, eax
;; UINT32 EFlags;
pop dword [ecx + IA32_TSS.EFLAGS]
;; UINT32 Ldtr, Tr;
;; UINT32 Gdtr[2], Idtr[2];
;; Best not let anyone mess with these particular registers...
add esp, 24
;; UINT32 Eip;
pop dword [ecx + IA32_TSS.EIP]
;; UINT32 Gs, Fs, Es, Ds, Cs, Ss;
;; NOTE - modified segment registers could hang the debugger... We
;; could attempt to insulate ourselves against this possibility,
;; but that poses risks as well.
;;
pop eax
o16 mov [ecx + IA32_TSS._GS], ax
pop eax
o16 mov [ecx + IA32_TSS._FS], ax
pop eax
o16 mov [ecx + IA32_TSS._ES], ax
pop eax
o16 mov [ecx + IA32_TSS._DS], ax
pop eax
o16 mov [ecx + IA32_TSS._CS], ax
pop eax
o16 mov [ecx + IA32_TSS._SS], ax
;; UINT32 Edi, Esi, Ebp, Esp, Ebx, Edx, Ecx, Eax;
pop dword [ecx + IA32_TSS._EDI]
pop dword [ecx + IA32_TSS._ESI]
add esp, 4 ; not for ebp
add esp, 4 ; not for esp
pop dword [ecx + IA32_TSS._EBX]
pop dword [ecx + IA32_TSS._EDX]
pop dword [ecx + IA32_TSS._ECX]
pop dword [ecx + IA32_TSS._EAX]
mov esp, ebp
; Set single step DB# if SMM profile is enabled and page fault exception happens
cmp byte [dword ASM_PFX(mSetupDebugTrap)], 0
jz @Done2
; Create return context for iretd in stub function
mov eax, dword [ecx + IA32_TSS._ESP] ; Get old stack pointer
mov ebx, dword [ecx + IA32_TSS.EIP]
mov [eax - 0xc], ebx ; create EIP in old stack
movzx ebx, word [ecx + IA32_TSS._CS]
mov [eax - 0x8], ebx ; create CS in old stack
mov ebx, dword [ecx + IA32_TSS.EFLAGS]
bts ebx, 8
mov [eax - 0x4], ebx ; create eflags in old stack
mov eax, dword [ecx + IA32_TSS._ESP] ; Get old stack pointer
sub eax, 0xc ; minus 12 byte
mov dword [ecx + IA32_TSS._ESP], eax ; Set new stack pointer
; Replace the EIP of interrupted task with stub function
mov eax, ASM_PFX(PageFaultStubFunction)
mov dword [ecx + IA32_TSS.EIP], eax
; Jump to the iretd so next page fault handler as a task will start again after iretd.
@Done2:
add esp, 4 ; skip ErrCode
jmp Return
global ASM_PFX(PageFaultStubFunction)
ASM_PFX(PageFaultStubFunction):
;
; we need clean TS bit in CR0 to execute
; x87 FPU/MMX/SSE/SSE2/SSE3/SSSE3/SSE4 instructions.
;
clts
iretd
|
