.../CpuExceptionHandlerLib/CpuExceptionCommon.h | 50 +++ .../DxeCpuExceptionHandlerLib.inf | 6 + .../Library/CpuExceptionHandlerLib/DxeException.c | 53 ++- .../Ia32/ArchExceptionHandler.c | 167 +++++++++ .../Ia32/ArchInterruptDefs.h | 8 + .../Ia32/ExceptionTssEntryAsm.nasm | 398 +++++++++++++++++++++ .../PeiCpuExceptionHandlerLib.inf | 1 + .../SecPeiCpuExceptionHandlerLib.inf | 1 + .../SmmCpuExceptionHandlerLib.inf | 1 + .../X64/ArchExceptionHandler.c | 133 +++++++ .../CpuExceptionHandlerLib/X64/ArchInterruptDefs.h | 3 + 11 files changed, 820 insertions(+), 1 deletion(-) create mode 100644 UefiCpuPkg/Library/CpuExceptionHandlerLib/Ia32/ExceptionTssEntryAsm.nasm
Jian,
EFIAPI is not required for ArchSetupExcpetionStack().
Reviewed-by: Jeff Fan <vanjeff_919@hotmail.com>
Jeff
________________________________
From: edk2-devel <edk2-devel-bounces@lists.01.org> on behalf of Jian J Wang <jian.j.wang@intel.com>
Sent: Wednesday, November 22, 2017 4:45:47 PM
To: edk2-devel@lists.01.org
Cc: Michael Kinney; Jiewen Yao; Eric Dong; Star Zeng
Subject: [edk2] [PATCH v2 7/8] UefiCpuPkg/CpuExceptionHandlerLib: Add stack switch support
> v2:
> a. Move common TSS structure and API definitions to BaseLib.h
> b. Add EXCEPTION_STACK_SWITCH_DATA to convery data used to setup stack
> switch. This can avoid allocating memory for it in this library.
> c. Add globals to reserve memory for stack switch initialized in early
> phase of DXE core.
> d. Remove the filter code used to exclude boot modes which doesn't support
> memory allocation because those memory can passed in by parameter now.
> e. Remove the nasm macro to define exception handler one by one and add a
> function to return the start address of each handler.
If Stack Guard is enabled and there's really a stack overflow happened during
boot, a Page Fault exception will be triggered. Because the stack is out of
usage, the exception handler, which shares the stack with normal UEFI driver,
cannot be executed and cannot dump the processor information.
Without those information, it's very difficult for the BIOS developers locate
the root cause of stack overflow. And without a workable stack, the developer
cannot event use single step to debug the UEFI driver with JTAG debugger.
In order to make sure the exception handler to execute normally after stack
overflow. We need separate stacks for exception handlers in case of unusable
stack.
IA processor allows to switch to a new stack during handling interrupt and
exception. But X64 and IA32 provides different ways to make it. X64 provides
interrupt stack table (IST) to allow maximum 7 different exceptions to have
new stack for its handler. IA32 doesn't have IST mechanism and can only use
task gate to do it since task switch allows to load a new stack through its
task-state segment (TSS).
Cc: Star Zeng <star.zeng@intel.com>
Cc: Eric Dong <eric.dong@intel.com>
Cc: Jiewen Yao <jiewen.yao@intel.com>
Cc: Michael Kinney <michael.d.kinney@intel.com>
Suggested-by: Ayellet Wolman <ayellet.wolman@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Jian J Wang <jian.j.wang@intel.com>
---
.../CpuExceptionHandlerLib/CpuExceptionCommon.h | 50 +++
.../DxeCpuExceptionHandlerLib.inf | 6 +
.../Library/CpuExceptionHandlerLib/DxeException.c | 53 ++-
.../Ia32/ArchExceptionHandler.c | 167 +++++++++
.../Ia32/ArchInterruptDefs.h | 8 +
.../Ia32/ExceptionTssEntryAsm.nasm | 398 +++++++++++++++++++++
.../PeiCpuExceptionHandlerLib.inf | 1 +
.../SecPeiCpuExceptionHandlerLib.inf | 1 +
.../SmmCpuExceptionHandlerLib.inf | 1 +
.../X64/ArchExceptionHandler.c | 133 +++++++
.../CpuExceptionHandlerLib/X64/ArchInterruptDefs.h | 3 +
11 files changed, 820 insertions(+), 1 deletion(-)
create mode 100644 UefiCpuPkg/Library/CpuExceptionHandlerLib/Ia32/ExceptionTssEntryAsm.nasm
diff --git a/UefiCpuPkg/Library/CpuExceptionHandlerLib/CpuExceptionCommon.h b/UefiCpuPkg/Library/CpuExceptionHandlerLib/CpuExceptionCommon.h
index 740a58828b..30334105d2 100644
--- a/UefiCpuPkg/Library/CpuExceptionHandlerLib/CpuExceptionCommon.h
+++ b/UefiCpuPkg/Library/CpuExceptionHandlerLib/CpuExceptionCommon.h
@@ -48,6 +48,32 @@
0xb21d9148, 0x9211, 0x4d8f, { 0xad, 0xd3, 0x66, 0xb1, 0x89, 0xc9, 0x2c, 0x83 } \
}
+#define CPU_STACK_SWITCH_EXCEPTION_NUMBER \
+ FixedPcdGetSize (PcdCpuStackSwitchExceptionList)
+
+#define CPU_STACK_SWITCH_EXCEPTION_LIST \
+ FixedPcdGetPtr (PcdCpuStackSwitchExceptionList)
+
+#define CPU_KNOWN_GOOD_STACK_SIZE \
+ FixedPcdGet32 (PcdCpuKnownGoodStackSize)
+
+#define CPU_TSS_GDT_SIZE (SIZE_2KB + CPU_TSS_DESC_SIZE + CPU_TSS_SIZE)
+
+#define IA32_GDT_TYPE_TSS 0x9
+#define IA32_GDT_ALIGNMENT 8
+
+typedef struct {
+ UINTN StackTop;
+ UINTN StackSize;
+ UINT8 *Exceptions;
+ UINTN ExceptionNumber;
+ IA32_IDT_GATE_DESCRIPTOR *IdtTable;
+ IA32_SEGMENT_DESCRIPTOR *GdtTable;
+ UINTN GdtSize;
+ IA32_TSS_DESCRIPTOR *TssDesc;
+ IA32_TASK_STATE_SEGMENT *Tss;
+} EXCEPTION_STACK_SWITCH_DATA;
+
//
// Record exception handler information
//
@@ -288,5 +314,29 @@ CommonExceptionHandlerWorker (
IN EXCEPTION_HANDLER_DATA *ExceptionHandlerData
);
+/**
+ Setup separate stack for specific exceptions.
+
+ @param[in] IdtTable IDT table base.
+**/
+EFI_STATUS
+EFIAPI
+ArchSetupExcpetionStack (
+ IN EXCEPTION_STACK_SWITCH_DATA *StackSwitchData
+ );
+
+/**
+ Return address map of exception handler template so that C code can generate
+ exception tables. The template is only for exceptions using task gate instead
+ of interrupt gate.
+
+ @param AddressMap Pointer to a buffer where the address map is returned.
+**/
+VOID
+EFIAPI
+AsmGetTssTemplateMap (
+ OUT EXCEPTION_HANDLER_TEMPLATE_MAP *AddressMap
+ );
+
#endif
diff --git a/UefiCpuPkg/Library/CpuExceptionHandlerLib/DxeCpuExceptionHandlerLib.inf b/UefiCpuPkg/Library/CpuExceptionHandlerLib/DxeCpuExceptionHandlerLib.inf
index f4a8d01c80..58e55a8a2e 100644
--- a/UefiCpuPkg/Library/CpuExceptionHandlerLib/DxeCpuExceptionHandlerLib.inf
+++ b/UefiCpuPkg/Library/CpuExceptionHandlerLib/DxeCpuExceptionHandlerLib.inf
@@ -30,6 +30,7 @@
[Sources.Ia32]
Ia32/ExceptionHandlerAsm.asm
Ia32/ExceptionHandlerAsm.nasm
+ Ia32/ExceptionTssEntryAsm.nasm
Ia32/ExceptionHandlerAsm.S
Ia32/ArchExceptionHandler.c
Ia32/ArchInterruptDefs.h
@@ -47,6 +48,11 @@
PeiDxeSmmCpuException.c
DxeException.c
+[Pcd]
+ gEfiMdeModulePkgTokenSpaceGuid.PcdCpuStackGuard
+ gUefiCpuPkgTokenSpaceGuid.PcdCpuStackSwitchExceptionList
+ gUefiCpuPkgTokenSpaceGuid.PcdCpuKnownGoodStackSize
+
[Packages]
MdePkg/MdePkg.dec
MdeModulePkg/MdeModulePkg.dec
diff --git a/UefiCpuPkg/Library/CpuExceptionHandlerLib/DxeException.c b/UefiCpuPkg/Library/CpuExceptionHandlerLib/DxeException.c
index 31febec976..c0b2c615aa 100644
--- a/UefiCpuPkg/Library/CpuExceptionHandlerLib/DxeException.c
+++ b/UefiCpuPkg/Library/CpuExceptionHandlerLib/DxeException.c
@@ -25,6 +25,10 @@ UINTN mEnabledInterruptNum = 0;
EXCEPTION_HANDLER_DATA mExceptionHandlerData;
+UINT8 mNewStack[CPU_STACK_SWITCH_EXCEPTION_NUMBER *
+ CPU_KNOWN_GOOD_STACK_SIZE] = {0};
+UINT8 mNewGdt[CPU_TSS_GDT_SIZE] = {0};
+
/**
Common exception handler.
@@ -63,10 +67,34 @@ InitializeCpuExceptionHandlers (
IN EFI_VECTOR_HANDOFF_INFO *VectorInfo OPTIONAL
)
{
+ EFI_STATUS Status;
+ EXCEPTION_STACK_SWITCH_DATA StackSwitchData;
+ IA32_DESCRIPTOR Idtr;
+ IA32_DESCRIPTOR Gdtr;
+
mExceptionHandlerData.ReservedVectors = mReservedVectorsData;
mExceptionHandlerData.ExternalInterruptHandler = mExternalInterruptHandlerTable;
InitializeSpinLock (&mExceptionHandlerData.DisplayMessageSpinLock);
- return InitializeCpuExceptionHandlersWorker (VectorInfo, &mExceptionHandlerData);
+ Status = InitializeCpuExceptionHandlersWorker (VectorInfo, &mExceptionHandlerData);
+ if (!EFI_ERROR (Status) && PcdGetBool (PcdCpuStackGuard)) {
+ AsmReadIdtr (&Idtr);
+ AsmReadGdtr (&Gdtr);
+
+ StackSwitchData.StackTop = (UINTN)mNewStack;
+ StackSwitchData.StackSize = CPU_KNOWN_GOOD_STACK_SIZE;
+ StackSwitchData.Exceptions = CPU_STACK_SWITCH_EXCEPTION_LIST;
+ StackSwitchData.ExceptionNumber = CPU_STACK_SWITCH_EXCEPTION_NUMBER;
+ StackSwitchData.IdtTable = (IA32_IDT_GATE_DESCRIPTOR *)Idtr.Base;
+ StackSwitchData.GdtTable = (IA32_SEGMENT_DESCRIPTOR *)mNewGdt;
+ StackSwitchData.GdtSize = sizeof (mNewGdt);
+ StackSwitchData.TssDesc = (IA32_TSS_DESCRIPTOR *)(mNewGdt + Gdtr.Limit + 1);
+ StackSwitchData.Tss = (IA32_TASK_STATE_SEGMENT *)(mNewGdt + Gdtr.Limit + 1 +
+ CPU_TSS_DESC_SIZE);
+ Status = InitializeCpuExceptionStackSwitchHandlers (
+ &StackSwitchData
+ );
+ }
+ return Status;
}
/**
@@ -197,3 +225,26 @@ RegisterCpuInterruptHandler (
{
return RegisterCpuInterruptHandlerWorker (InterruptType, InterruptHandler, &mExceptionHandlerData);
}
+
+/**
+ Setup separate stack for given exceptions. This is required by
+ PcdCpuStackGuard feature.
+
+ Note: For IA32 processor, StackSwitchData is a required parameter.
+
+ @param[in] StackSwitchData Pointer to data required for setuping up
+ stack switch.
+
+ @retval EFI_SUCCESS The exceptions have been successfully
+ initialized.
+ @retval EFI_INVALID_PARAMETER StackSwitchData contains invalid content.
+
+**/
+EFI_STATUS
+EFIAPI
+InitializeCpuExceptionStackSwitchHandlers (
+ IN VOID *StackSwitchData OPTIONAL
+ )
+{
+ return ArchSetupExcpetionStack (StackSwitchData);
+}
diff --git a/UefiCpuPkg/Library/CpuExceptionHandlerLib/Ia32/ArchExceptionHandler.c b/UefiCpuPkg/Library/CpuExceptionHandlerLib/Ia32/ArchExceptionHandler.c
index f2c39eb193..0aaf794795 100644
--- a/UefiCpuPkg/Library/CpuExceptionHandlerLib/Ia32/ArchExceptionHandler.c
+++ b/UefiCpuPkg/Library/CpuExceptionHandlerLib/Ia32/ArchExceptionHandler.c
@@ -107,6 +107,173 @@ ArchRestoreExceptionContext (
SystemContext.SystemContextIa32->ExceptionData = ReservedVectors[ExceptionType].ExceptionData;
}
+/**
+ Setup separate stack for given exceptions.
+
+ @param[in] StackSwitchData Pointer to data required for setuping up
+ stack switch.
+ @retval EFI_SUCCESS The exceptions have been successfully
+ initialized.
+ @retval EFI_INVALID_PARAMETER StackSwitchData contains invalid content.
+
+**/
+EFI_STATUS
+EFIAPI
+ArchSetupExcpetionStack (
+ IN EXCEPTION_STACK_SWITCH_DATA *StackSwitchData
+ )
+{
+ IA32_DESCRIPTOR Gdtr;
+ IA32_DESCRIPTOR Idtr;
+ IA32_IDT_GATE_DESCRIPTOR *IdtTable;
+ IA32_TSS_DESCRIPTOR *TssDesc;
+ IA32_TASK_STATE_SEGMENT *Tss;
+ UINTN StackTop;
+ UINTN Index;
+ UINTN Vector;
+ UINTN TssBase;
+ UINTN GdtSize;
+ EXCEPTION_HANDLER_TEMPLATE_MAP TemplateMap;
+
+ if (StackSwitchData == NULL ||
+ StackSwitchData->StackTop == 0 ||
+ StackSwitchData->StackSize == 0 ||
+ StackSwitchData->Exceptions == NULL ||
+ StackSwitchData->ExceptionNumber == 0 ||
+ StackSwitchData->GdtTable == NULL ||
+ StackSwitchData->IdtTable == NULL ||
+ StackSwitchData->TssDesc == NULL ||
+ StackSwitchData->Tss == NULL) {
+ return EFI_INVALID_PARAMETER;
+ }
+
+ //
+ // The caller is responsible for that the GDT table, no matter the existing
+ // one or newly allocated, has enough space to hold descriptors for exception
+ // task-state segments.
+ //
+ if (((UINTN)StackSwitchData->GdtTable & (IA32_GDT_ALIGNMENT - 1)) != 0) {
+ return EFI_INVALID_PARAMETER;
+ }
+
+ if ((UINTN)StackSwitchData->TssDesc < (UINTN)(StackSwitchData->GdtTable)) {
+ return EFI_INVALID_PARAMETER;
+ }
+
+ if ((UINTN)StackSwitchData->TssDesc >=
+ ((UINTN)(StackSwitchData->GdtTable) + StackSwitchData->GdtSize)) {
+ return EFI_INVALID_PARAMETER;
+ }
+
+ GdtSize = (UINTN)StackSwitchData->TssDesc -
+ (UINTN)(StackSwitchData->GdtTable) +
+ sizeof (IA32_TSS_DESCRIPTOR) *
+ (StackSwitchData->ExceptionNumber + 1);
+ if (GdtSize > StackSwitchData->GdtSize) {
+ return EFI_INVALID_PARAMETER;
+ }
+
+ //
+ // Initialize new GDT table and/or IDT table, if any
+ //
+ AsmReadIdtr (&Idtr);
+ AsmReadGdtr (&Gdtr);
+ if ((UINTN)StackSwitchData->GdtTable != Gdtr.Base) {
+ CopyMem (StackSwitchData->GdtTable, (VOID *)Gdtr.Base, Gdtr.Limit + 1);
+ Gdtr.Base = (UINTN)StackSwitchData->GdtTable;
+ Gdtr.Limit = (UINT16)StackSwitchData->GdtSize - 1;
+ }
+
+ if ((UINTN)StackSwitchData->IdtTable != Idtr.Base) {
+ Idtr.Base = (UINTN)StackSwitchData->IdtTable;
+ }
+
+ //
+ // Fixup current task descriptor. Task-state segment for current task will
+ // be filled by processor during task switching.
+ //
+ TssDesc = StackSwitchData->TssDesc;
+ Tss = StackSwitchData->Tss;
+
+ TssBase = (UINTN)Tss;
+ TssDesc->Bits.LimitLow = sizeof(IA32_TASK_STATE_SEGMENT) - 1;
+ TssDesc->Bits.BaseLow = (UINT16)TssBase;
+ TssDesc->Bits.BaseMid = (UINT8)(TssBase >> 16);
+ TssDesc->Bits.Type = IA32_GDT_TYPE_TSS;
+ TssDesc->Bits.P = 1;
+ TssDesc->Bits.LimitHigh = 0;
+ TssDesc->Bits.BaseHigh = (UINT8)(TssBase >> 24);
+
+ //
+ // Fixup exception task descriptor and task-state segment
+ //
+ AsmGetTssTemplateMap (&TemplateMap);
+ StackTop = StackSwitchData->StackTop - CPU_STACK_ALIGNMENT;
+ StackTop = (UINTN)ALIGN_POINTER (StackTop, CPU_STACK_ALIGNMENT);
+ IdtTable = StackSwitchData->IdtTable;
+ for (Index = 0; Index < StackSwitchData->ExceptionNumber; ++Index) {
+ TssDesc += 1;
+ Tss += 1;
+
+ //
+ // Fixup TSS descriptor
+ //
+ TssBase = (UINTN)Tss;
+
+ TssDesc->Bits.LimitLow = sizeof(IA32_TASK_STATE_SEGMENT) - 1;
+ TssDesc->Bits.BaseLow = (UINT16)TssBase;
+ TssDesc->Bits.BaseMid = (UINT8)(TssBase >> 16);
+ TssDesc->Bits.Type = IA32_GDT_TYPE_TSS;
+ TssDesc->Bits.P = 1;
+ TssDesc->Bits.LimitHigh = 0;
+ TssDesc->Bits.BaseHigh = (UINT8)(TssBase >> 24);
+
+ //
+ // Fixup TSS
+ //
+ Vector = StackSwitchData->Exceptions[Index];
+ Tss->EIP = (UINT32)(TemplateMap.ExceptionStart
+ + Vector * TemplateMap.ExceptionStubHeaderSize);
+ Tss->EFLAGS = 0x2;
+ Tss->ESP = StackTop;
+ Tss->CR3 = AsmReadCr3 ();
+ Tss->ES = AsmReadEs ();
+ Tss->CS = AsmReadCs ();
+ Tss->SS = AsmReadSs ();
+ Tss->DS = AsmReadDs ();
+ Tss->FS = AsmReadFs ();
+ Tss->GS = AsmReadGs ();
+
+ StackTop -= StackSwitchData->StackSize;
+
+ //
+ // Update IDT to use Task Gate for given exception
+ //
+ IdtTable[Vector].Bits.OffsetLow = 0;
+ IdtTable[Vector].Bits.Selector = (UINT16)((UINTN)TssDesc - Gdtr.Base);
+ IdtTable[Vector].Bits.Reserved_0 = 0;
+ IdtTable[Vector].Bits.GateType = IA32_IDT_GATE_TYPE_TASK;
+ IdtTable[Vector].Bits.OffsetHigh = 0;
+ }
+
+ //
+ // Publish GDT
+ //
+ AsmWriteGdtr (&Gdtr);
+
+ //
+ // Load current task
+ //
+ AsmWriteTr ((UINT16)((UINTN)StackSwitchData->TssDesc - Gdtr.Base));
+
+ //
+ // Publish IDT
+ //
+ AsmWriteIdtr (&Idtr);
+
+ return EFI_SUCCESS;
+}
+
/**
Display processor context.
diff --git a/UefiCpuPkg/Library/CpuExceptionHandlerLib/Ia32/ArchInterruptDefs.h b/UefiCpuPkg/Library/CpuExceptionHandlerLib/Ia32/ArchInterruptDefs.h
index a8d3556a80..d9ded5977f 100644
--- a/UefiCpuPkg/Library/CpuExceptionHandlerLib/Ia32/ArchInterruptDefs.h
+++ b/UefiCpuPkg/Library/CpuExceptionHandlerLib/Ia32/ArchInterruptDefs.h
@@ -41,4 +41,12 @@ typedef struct {
UINT8 HookAfterStubHeaderCode[HOOKAFTER_STUB_SIZE];
} RESERVED_VECTORS_DATA;
+#define CPU_TSS_DESC_SIZE \
+ (sizeof (IA32_TSS_DESCRIPTOR) * \
+ (PcdGetSize (PcdCpuStackSwitchExceptionList) + 1))
+
+#define CPU_TSS_SIZE \
+ (sizeof (IA32_TASK_STATE_SEGMENT) * \
+ (PcdGetSize (PcdCpuStackSwitchExceptionList) + 1))
+
#endif
diff --git a/UefiCpuPkg/Library/CpuExceptionHandlerLib/Ia32/ExceptionTssEntryAsm.nasm b/UefiCpuPkg/Library/CpuExceptionHandlerLib/Ia32/ExceptionTssEntryAsm.nasm
new file mode 100644
index 0000000000..62bcedea1a
--- /dev/null
+++ b/UefiCpuPkg/Library/CpuExceptionHandlerLib/Ia32/ExceptionTssEntryAsm.nasm
@@ -0,0 +1,398 @@
+;------------------------------------------------------------------------------ ;
+; Copyright (c) 2017, 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.
+;
+; Module Name:
+;
+; ExceptionTssEntryAsm.Asm
+;
+; Abstract:
+;
+; IA32 CPU Exception Handler with Separate Stack
+;
+; Notes:
+;
+;------------------------------------------------------------------------------
+
+;
+; IA32 TSS Memory Layout Description
+;
+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
+
+;
+; CommonExceptionHandler()
+;
+extern ASM_PFX(CommonExceptionHandler)
+
+SECTION .data
+
+SECTION .text
+
+ALIGN 8
+
+;
+; Exception handler stub table
+;
+AsmExceptionEntryBegin:
+%assign Vector 0
+%rep 32
+
+DoIret%[Vector]:
+ iretd
+ASM_PFX(ExceptionTaskSwtichEntry%[Vector]):
+ db 0x6a ; push #VectorNum
+ db %[Vector]
+ mov eax, ASM_PFX(CommonTaskSwtichEntryPoint)
+ call eax
+ mov esp, eax ; Restore stack top
+ jmp DoIret%[Vector]
+
+%assign Vector Vector+1
+%endrep
+AsmExceptionEntryEnd:
+
+;
+; Common part of exception handler
+;
+global ASM_PFX(CommonTaskSwtichEntryPoint)
+ASM_PFX(CommonTaskSwtichEntryPoint):
+ ;
+ ; Stack:
+ ; +---------------------+ <-- EBP - 8
+ ; + TSS Base +
+ ; +---------------------+ <-- EBP - 4
+ ; + CPUID.EDX +
+ ; +---------------------+ <-- EBP
+ ; + EIP +
+ ; +---------------------+ <-- EBP + 4
+ ; + Vector Number +
+ ; +---------------------+ <-- EBP + 8
+ ; + Error Code +
+ ; +---------------------+
+ ;
+
+ mov ebp, esp ; Stack frame
+
+; Use CPUID to determine if FXSAVE/FXRESTOR and DE are supported
+ mov eax, 1
+ cpuid
+ push edx
+
+; Get TSS base of interrupted task through PreviousTaskLink field in
+; current TSS base
+ sub esp, 8
+ sgdt [esp + 2]
+ mov eax, [esp + 4] ; GDT base
+ add esp, 8
+
+ xor ebx, ebx
+ str bx ; Current TR
+
+ mov ecx, [eax + ebx + 2]
+ shl ecx, 8
+ mov cl, [eax + ebx + 7]
+ ror ecx, 8 ; ecx = Current TSS base
+ push ecx ; keep it in stack for later use
+
+ movzx ebx, word [ecx] ; Previous Task Link
+ mov ecx, [eax + ebx + 2]
+ shl ecx, 8
+ mov cl, [eax + ebx + 7]
+ ror ecx, 8 ; ecx = Previous TSS base
+
+;
+; 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, ebx ; ebx still keeps selector of interrupted task
+ 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
+ push eax ; push cr4 firstly
+
+ mov edx, [ebp - 4] ; cpuid.edx
+ test edx, BIT24 ; Test for FXSAVE/FXRESTOR support
+ jz .1
+ or eax, BIT9 ; Set CR4.OSFXSR
+.1:
+ test edx, BIT2 ; Test for Debugging Extensions support
+ jz .2
+ or eax, BIT3 ; Set CR4.DE
+.2:
+ mov cr4, 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
+ test edx, BIT24 ; Test for FXSAVE/FXRESTOR support.
+ ; edx still contains result from CPUID above
+ jz .3
+ clts
+ sub esp, 512
+ mov edi, esp
+ db 0xf, 0xae, 0x7 ;fxsave [edi]
+.3:
+
+;; UINT32 ExceptionData;
+ push dword [ebp + 8]
+
+;; UEFI calling convention for IA32 requires that Direction flag in EFLAGs is clear
+ cld
+
+;; call into exception handler
+ mov esi, ecx ; Keep TSS base to avoid overwrite
+ mov eax, ASM_PFX(CommonExceptionHandler)
+
+;; Prepare parameter and call
+ mov edx, esp
+ push edx ; EFI_SYSTEM_CONTEXT
+ push dword [ebp + 4] ; EFI_EXCEPTION_TYPE (vector number)
+
+ ;
+ ; Call External Exception Handler
+ ;
+ call eax
+ add esp, 8 ; Restore stack before calling
+ mov ecx, esi ; Restore TSS base
+
+;; UINT32 ExceptionData;
+ add esp, 4
+
+;; FX_SAVE_STATE_IA32 FxSaveState;
+ mov edx, [ebp - 4] ; cpuid.edx
+ test edx, BIT24 ; Test for FXSAVE/FXRESTOR support
+ jz .4
+ mov esi, esp
+ db 0xf, 0xae, 0xe ; fxrstor [esi]
+.4:
+ 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]
+ mov ebx, dword [ecx + IA32_TSS.EFLAGS]
+ btr ebx, 9 ; Do 'cli'
+ mov dword [ecx + IA32_TSS.EFLAGS], ebx
+
+;; 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]
+
+; Set single step DB# to allow debugger to able to go back to the EIP
+; where the exception is triggered.
+
+;; 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 dword [ecx + IA32_TSS.EFLAGS], ebx ; update eflags in old TSS
+ 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(SingleStepStubFunction)
+ mov dword [ecx + IA32_TSS.EIP], eax
+
+ mov ecx, [ebp - 8] ; Get current TSS base
+ mov eax, dword [ecx + IA32_TSS._ESP] ; Return current stack top
+ mov esp, ebp
+
+ ret
+
+global ASM_PFX(SingleStepStubFunction)
+ASM_PFX(SingleStepStubFunction):
+;
+; we need clean TS bit in CR0 to execute
+; x87 FPU/MMX/SSE/SSE2/SSE3/SSSE3/SSE4 instructions.
+;
+ clts
+ iretd
+
+global ASM_PFX(AsmGetTssTemplateMap)
+ASM_PFX(AsmGetTssTemplateMap):
+ push ebp ; C prolog
+ mov ebp, esp
+ pushad
+
+ mov ebx, dword [ebp + 0x8]
+ mov dword [ebx], ASM_PFX(ExceptionTaskSwtichEntry0)
+ mov dword [ebx + 0x4], (AsmExceptionEntryEnd - AsmExceptionEntryBegin) / 32
+ mov dword [ebx + 0x8], 0
+
+ popad
+ pop ebp
+ ret
+
diff --git a/UefiCpuPkg/Library/CpuExceptionHandlerLib/PeiCpuExceptionHandlerLib.inf b/UefiCpuPkg/Library/CpuExceptionHandlerLib/PeiCpuExceptionHandlerLib.inf
index 75443288a9..4c0d435136 100644
--- a/UefiCpuPkg/Library/CpuExceptionHandlerLib/PeiCpuExceptionHandlerLib.inf
+++ b/UefiCpuPkg/Library/CpuExceptionHandlerLib/PeiCpuExceptionHandlerLib.inf
@@ -30,6 +30,7 @@
[Sources.Ia32]
Ia32/ExceptionHandlerAsm.asm
Ia32/ExceptionHandlerAsm.nasm
+ Ia32/ExceptionTssEntryAsm.nasm
Ia32/ExceptionHandlerAsm.S
Ia32/ArchExceptionHandler.c
Ia32/ArchInterruptDefs.h
diff --git a/UefiCpuPkg/Library/CpuExceptionHandlerLib/SecPeiCpuExceptionHandlerLib.inf b/UefiCpuPkg/Library/CpuExceptionHandlerLib/SecPeiCpuExceptionHandlerLib.inf
index d70a99c100..e5c03c16c9 100644
--- a/UefiCpuPkg/Library/CpuExceptionHandlerLib/SecPeiCpuExceptionHandlerLib.inf
+++ b/UefiCpuPkg/Library/CpuExceptionHandlerLib/SecPeiCpuExceptionHandlerLib.inf
@@ -30,6 +30,7 @@
[Sources.Ia32]
Ia32/ExceptionHandlerAsm.asm
Ia32/ExceptionHandlerAsm.nasm
+ Ia32/ExceptionTssEntryAsm.nasm
Ia32/ExceptionHandlerAsm.S
Ia32/ArchExceptionHandler.c
Ia32/ArchInterruptDefs.h
diff --git a/UefiCpuPkg/Library/CpuExceptionHandlerLib/SmmCpuExceptionHandlerLib.inf b/UefiCpuPkg/Library/CpuExceptionHandlerLib/SmmCpuExceptionHandlerLib.inf
index 634ffcb21d..56b875b7c8 100644
--- a/UefiCpuPkg/Library/CpuExceptionHandlerLib/SmmCpuExceptionHandlerLib.inf
+++ b/UefiCpuPkg/Library/CpuExceptionHandlerLib/SmmCpuExceptionHandlerLib.inf
@@ -30,6 +30,7 @@
[Sources.Ia32]
Ia32/ExceptionHandlerAsm.asm
Ia32/ExceptionHandlerAsm.nasm
+ Ia32/ExceptionTssEntryAsm.nasm
Ia32/ExceptionHandlerAsm.S
Ia32/ArchExceptionHandler.c
Ia32/ArchInterruptDefs.h
diff --git a/UefiCpuPkg/Library/CpuExceptionHandlerLib/X64/ArchExceptionHandler.c b/UefiCpuPkg/Library/CpuExceptionHandlerLib/X64/ArchExceptionHandler.c
index 65f0cff680..214aafcc13 100644
--- a/UefiCpuPkg/Library/CpuExceptionHandlerLib/X64/ArchExceptionHandler.c
+++ b/UefiCpuPkg/Library/CpuExceptionHandlerLib/X64/ArchExceptionHandler.c
@@ -112,6 +112,139 @@ ArchRestoreExceptionContext (
SystemContext.SystemContextX64->ExceptionData = ReservedVectors[ExceptionType].ExceptionData;
}
+/**
+ Setup separate stack for given exceptions.
+
+ @param[in] StackSwitchData Pointer to data required for setuping up
+ stack switch.
+
+ @retval EFI_SUCCESS The exceptions have been successfully
+ initialized.
+ @retval EFI_INVALID_PARAMETER StackSwitchData contains invalid content.
+
+**/
+EFI_STATUS
+EFIAPI
+ArchSetupExcpetionStack (
+ IN EXCEPTION_STACK_SWITCH_DATA *StackSwitchData
+ )
+{
+ IA32_DESCRIPTOR Gdtr;
+ IA32_DESCRIPTOR Idtr;
+ IA32_IDT_GATE_DESCRIPTOR *IdtTable;
+ IA32_TSS_DESCRIPTOR *TssDesc;
+ IA32_TASK_STATE_SEGMENT *Tss;
+ UINTN StackTop;
+ UINTN Index;
+ UINTN TssBase;
+ UINTN GdtSize;
+
+ if (StackSwitchData == NULL ||
+ StackSwitchData->StackTop == 0 ||
+ StackSwitchData->StackSize == 0 ||
+ StackSwitchData->Exceptions == NULL ||
+ StackSwitchData->ExceptionNumber == 0 ||
+ StackSwitchData->GdtTable == NULL ||
+ StackSwitchData->IdtTable == NULL ||
+ StackSwitchData->TssDesc == NULL ||
+ StackSwitchData->Tss == NULL) {
+ return EFI_INVALID_PARAMETER;
+ }
+
+ //
+ // The caller is responsible for that the GDT table, no matter the existing
+ // one or newly allocated, has enough space to hold descriptors for exception
+ // task-state segments.
+ //
+ if (((UINTN)StackSwitchData->GdtTable & (IA32_GDT_ALIGNMENT - 1)) != 0) {
+ return EFI_INVALID_PARAMETER;
+ }
+
+ if ((UINTN)StackSwitchData->TssDesc < (UINTN)(StackSwitchData->GdtTable)) {
+ return EFI_INVALID_PARAMETER;
+ }
+
+ if ((UINTN)StackSwitchData->TssDesc >=
+ ((UINTN)(StackSwitchData->GdtTable) + StackSwitchData->GdtSize)) {
+ return EFI_INVALID_PARAMETER;
+ }
+
+ GdtSize = (UINTN)StackSwitchData->TssDesc -
+ (UINTN)(StackSwitchData->GdtTable) +
+ sizeof (IA32_TSS_DESCRIPTOR);
+ if (GdtSize > StackSwitchData->GdtSize) {
+ return EFI_INVALID_PARAMETER;
+ }
+
+ //
+ // Initialize new GDT table and/or IDT table, if any
+ //
+ AsmReadIdtr (&Idtr);
+ AsmReadGdtr (&Gdtr);
+ if ((UINTN)StackSwitchData->GdtTable != Gdtr.Base) {
+ CopyMem (StackSwitchData->GdtTable, (VOID *)Gdtr.Base, Gdtr.Limit + 1);
+ Gdtr.Base = (UINTN)StackSwitchData->GdtTable;
+ Gdtr.Limit = (UINT16)GdtSize - 1;
+ }
+
+ if ((UINTN)StackSwitchData->IdtTable != Idtr.Base) {
+ Idtr.Base = (UINTN)StackSwitchData->IdtTable;
+ }
+
+ //
+ // Fixup current task descriptor. Task-state segment for current task will
+ // be filled by processor during task switching.
+ //
+ TssDesc = StackSwitchData->TssDesc;
+ Tss = StackSwitchData->Tss;
+
+ TssBase = (UINTN)Tss;
+ TssDesc->Bits.LimitLow = sizeof(IA32_TASK_STATE_SEGMENT) - 1;
+ TssDesc->Bits.BaseLow = (UINT16)TssBase;
+ TssDesc->Bits.BaseMidl = (UINT8)(TssBase >> 16);
+ TssDesc->Bits.Type = IA32_GDT_TYPE_TSS;
+ TssDesc->Bits.P = 1;
+ TssDesc->Bits.LimitHigh = 0;
+ TssDesc->Bits.BaseMidh = (UINT8)(TssBase >> 24);
+ TssDesc->Bits.BaseHigh = (UINT32)(TssBase >> 32);
+
+ //
+ // Fixup exception task descriptor and task-state segment
+ //
+ StackTop = StackSwitchData->StackTop - CPU_STACK_ALIGNMENT;
+ StackTop = (UINTN)ALIGN_POINTER (StackTop, CPU_STACK_ALIGNMENT);
+ IdtTable = StackSwitchData->IdtTable;
+ for (Index = 0; Index < StackSwitchData->ExceptionNumber; ++Index) {
+ //
+ // Fixup IST
+ //
+ Tss->IST[Index] = StackTop;
+ StackTop -= StackSwitchData->StackSize;
+
+ //
+ // Set the IST field to enable corresponding IST
+ //
+ IdtTable[StackSwitchData->Exceptions[Index]].Bits.Reserved_0 = (UINT8)(Index + 1);
+ }
+
+ //
+ // Publish GDT
+ //
+ AsmWriteGdtr (&Gdtr);
+
+ //
+ // Load current task
+ //
+ AsmWriteTr ((UINT16)((UINTN)StackSwitchData->TssDesc - Gdtr.Base));
+
+ //
+ // Publish IDT
+ //
+ AsmWriteIdtr (&Idtr);
+
+ return EFI_SUCCESS;
+}
+
/**
Display CPU information.
diff --git a/UefiCpuPkg/Library/CpuExceptionHandlerLib/X64/ArchInterruptDefs.h b/UefiCpuPkg/Library/CpuExceptionHandlerLib/X64/ArchInterruptDefs.h
index 906480134a..c88be46286 100644
--- a/UefiCpuPkg/Library/CpuExceptionHandlerLib/X64/ArchInterruptDefs.h
+++ b/UefiCpuPkg/Library/CpuExceptionHandlerLib/X64/ArchInterruptDefs.h
@@ -43,4 +43,7 @@ typedef struct {
UINT8 HookAfterStubHeaderCode[HOOKAFTER_STUB_SIZE];
} RESERVED_VECTORS_DATA;
+#define CPU_TSS_DESC_SIZE sizeof (IA32_TSS_DESCRIPTOR)
+#define CPU_TSS_SIZE sizeof (IA32_TASK_STATE_SEGMENT)
+
#endif
--
2.14.1.windows.1
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