From 0ff5aa9cae1ea276668fa4398d047aa9fda3c2c7 Mon Sep 17 00:00:00 2001 From: Jian J Wang Date: Thu, 7 Dec 2017 20:15:12 +0800 Subject: [PATCH] UefiCpuPkg/CpuExceptionHandlerLib: Add stack switch support 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). The new API, InitializeCpuExceptionHandlersEx, is implemented to complete extra initialization for stack switch of exception handler. Since setting up stack switch needs allocating new memory for new stack, new GDT table and task-state segment but the initialization method will be called in different phases which have no consistent way to reserve those memory, this new API is allowed to pass the reserved resources to complete the extra works. This is cannot be done by original InitializeCpuExceptionHandlers. Considering exception handler initialization for MP situation, this new API is also necessary, because AP is not supposed to allocate memory. So the memory needed for stack switch have to be reserved in BSP before waking up AP and then pass them to InitializeCpuExceptionHandlersEx afterwards. Since Stack Guard feature is available only for DXE phase at this time, the new API is fully implemented for DXE only. Other phases implement a dummy one which just calls InitializeCpuExceptionHandlers(). Cc: Jiewen Yao Cc: Eric Dong Cc: Laszlo Ersek Cc: Michael Kinney Suggested-by: Ayellet Wolman Contributed-under: TianoCore Contribution Agreement 1.1 Signed-off-by: Jian J Wang Reviewed-by: Jeff Fan Reviewed-by: Jiewen.yao@intel.com --- .../CpuExceptionCommon.h | 39 ++ .../DxeCpuExceptionHandlerLib.inf | 6 + .../CpuExceptionHandlerLib/DxeException.c | 84 ++++ .../Ia32/ArchExceptionHandler.c | 188 +++++++++ .../Ia32/ArchInterruptDefs.h | 8 + .../Ia32/ExceptionTssEntryAsm.nasm | 398 ++++++++++++++++++ .../CpuExceptionHandlerLib/PeiCpuException.c | 34 +- .../PeiCpuExceptionHandlerLib.inf | 1 + .../SecPeiCpuException.c | 34 +- .../SecPeiCpuExceptionHandlerLib.inf | 1 + .../SmmCpuExceptionHandlerLib.inf | 1 + .../CpuExceptionHandlerLib/SmmException.c | 34 +- .../X64/ArchExceptionHandler.c | 156 +++++++ .../X64/ArchInterruptDefs.h | 3 + 14 files changed, 984 insertions(+), 3 deletions(-) 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..e10d9379d5 100644 --- a/UefiCpuPkg/Library/CpuExceptionHandlerLib/CpuExceptionCommon.h +++ b/UefiCpuPkg/Library/CpuExceptionHandlerLib/CpuExceptionCommon.h @@ -48,6 +48,17 @@ 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) + // // Record exception handler information // @@ -288,5 +299,33 @@ CommonExceptionHandlerWorker ( IN EXCEPTION_HANDLER_DATA *ExceptionHandlerData ); +/** + Setup separate stack for specific exceptions. + + @param[in] StackSwitchData Pointer to data required for setuping up + stack switch. + + @retval EFI_SUCCESS The exceptions have been successfully + initialized with new stack. + @retval EFI_INVALID_PARAMETER StackSwitchData contains invalid content. +**/ +EFI_STATUS +ArchSetupExcpetionStack ( + IN CPU_EXCEPTION_INIT_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..9a72b37e77 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]; +UINT8 mNewGdt[CPU_TSS_GDT_SIZE]; + /** Common exception handler. @@ -197,3 +201,83 @@ RegisterCpuInterruptHandler ( { return RegisterCpuInterruptHandlerWorker (InterruptType, InterruptHandler, &mExceptionHandlerData); } + +/** + Initializes CPU exceptions entries and setup stack switch for given exceptions. + + This method will call InitializeCpuExceptionHandlers() to setup default + exception handlers unless indicated not to do it explicitly. + + If InitData is passed with NULL, this method will use the resource reserved + by global variables to initialize it; Otherwise it will use data in InitData + to setup stack switch. This is for the different use cases in DxeCore and + Cpu MP exception initialization. + + @param[in] VectorInfo Pointer to reserved vector list. + @param[in] InitData Pointer to data required to setup stack switch for + given exceptions. + + @retval EFI_SUCCESS The exceptions have been successfully + initialized. + @retval EFI_INVALID_PARAMETER VectorInfo or InitData contains invalid + content. + +**/ +EFI_STATUS +EFIAPI +InitializeCpuExceptionHandlersEx ( + IN EFI_VECTOR_HANDOFF_INFO *VectorInfo OPTIONAL, + IN CPU_EXCEPTION_INIT_DATA *InitData OPTIONAL + ) +{ + EFI_STATUS Status; + CPU_EXCEPTION_INIT_DATA EssData; + IA32_DESCRIPTOR Idtr; + IA32_DESCRIPTOR Gdtr; + + // + // To avoid repeat initialization of default handlers, the caller should pass + // an extended init data with InitDefaultHandlers set to FALSE. There's no + // need to call this method to just initialize default handlers. Call non-ex + // version instead; or this method must be implemented as a simple wrapper of + // non-ex version of it, if this version has to be called. + // + if (InitData == NULL || InitData->X64.InitDefaultHandlers) { + Status = InitializeCpuExceptionHandlers (VectorInfo); + } else { + Status = EFI_SUCCESS; + } + + if (!EFI_ERROR (Status)) { + // + // Initializing stack switch is only necessary for Stack Guard functionality. + // + if (PcdGetBool (PcdCpuStackGuard)) { + if (InitData == NULL) { + SetMem (mNewGdt, sizeof (mNewGdt), 0); + + AsmReadIdtr (&Idtr); + AsmReadGdtr (&Gdtr); + + EssData.X64.Revision = CPU_EXCEPTION_INIT_DATA_REV; + EssData.X64.KnownGoodStackTop = (UINTN)mNewStack; + EssData.X64.KnownGoodStackSize = CPU_KNOWN_GOOD_STACK_SIZE; + EssData.X64.StackSwitchExceptions = CPU_STACK_SWITCH_EXCEPTION_LIST; + EssData.X64.StackSwitchExceptionNumber = CPU_STACK_SWITCH_EXCEPTION_NUMBER; + EssData.X64.IdtTable = (VOID *)Idtr.Base; + EssData.X64.IdtTableSize = Idtr.Limit + 1; + EssData.X64.GdtTable = mNewGdt; + EssData.X64.GdtTableSize = sizeof (mNewGdt); + EssData.X64.ExceptionTssDesc = mNewGdt + Gdtr.Limit + 1; + EssData.X64.ExceptionTssDescSize = CPU_TSS_DESC_SIZE; + EssData.X64.ExceptionTss = mNewGdt + Gdtr.Limit + 1 + CPU_TSS_DESC_SIZE; + EssData.X64.ExceptionTssSize = CPU_TSS_SIZE; + + InitData = &EssData; + } + Status = ArchSetupExcpetionStack (InitData); + } + } + + return Status; +} diff --git a/UefiCpuPkg/Library/CpuExceptionHandlerLib/Ia32/ArchExceptionHandler.c b/UefiCpuPkg/Library/CpuExceptionHandlerLib/Ia32/ArchExceptionHandler.c index f2c39eb193..6ac8549839 100644 --- a/UefiCpuPkg/Library/CpuExceptionHandlerLib/Ia32/ArchExceptionHandler.c +++ b/UefiCpuPkg/Library/CpuExceptionHandlerLib/Ia32/ArchExceptionHandler.c @@ -107,6 +107,194 @@ 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 with new stack. + @retval EFI_INVALID_PARAMETER StackSwitchData contains invalid content. + +**/ +EFI_STATUS +ArchSetupExcpetionStack ( + IN CPU_EXCEPTION_INIT_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->Ia32.Revision != CPU_EXCEPTION_INIT_DATA_REV || + StackSwitchData->Ia32.KnownGoodStackTop == 0 || + StackSwitchData->Ia32.KnownGoodStackSize == 0 || + StackSwitchData->Ia32.StackSwitchExceptions == NULL || + StackSwitchData->Ia32.StackSwitchExceptionNumber == 0 || + StackSwitchData->Ia32.StackSwitchExceptionNumber > CPU_EXCEPTION_NUM || + StackSwitchData->Ia32.GdtTable == NULL || + StackSwitchData->Ia32.IdtTable == NULL || + StackSwitchData->Ia32.ExceptionTssDesc == NULL || + StackSwitchData->Ia32.ExceptionTss == 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->Ia32.GdtTable & (IA32_GDT_ALIGNMENT - 1)) != 0) { + return EFI_INVALID_PARAMETER; + } + + if ((UINTN)StackSwitchData->Ia32.ExceptionTssDesc < (UINTN)(StackSwitchData->Ia32.GdtTable)) { + return EFI_INVALID_PARAMETER; + } + + if ((UINTN)StackSwitchData->Ia32.ExceptionTssDesc + StackSwitchData->Ia32.ExceptionTssDescSize > + ((UINTN)(StackSwitchData->Ia32.GdtTable) + StackSwitchData->Ia32.GdtTableSize)) { + return EFI_INVALID_PARAMETER; + } + + // + // We need one descriptor and one TSS for current task and every exception + // specified. + // + if (StackSwitchData->Ia32.ExceptionTssDescSize < + sizeof (IA32_TSS_DESCRIPTOR) * (StackSwitchData->Ia32.StackSwitchExceptionNumber + 1)) { + return EFI_INVALID_PARAMETER; + } + if (StackSwitchData->Ia32.ExceptionTssSize < + sizeof (IA32_TASK_STATE_SEGMENT) * (StackSwitchData->Ia32.StackSwitchExceptionNumber + 1)) { + return EFI_INVALID_PARAMETER; + } + + TssDesc = StackSwitchData->Ia32.ExceptionTssDesc; + Tss = StackSwitchData->Ia32.ExceptionTss; + + // + // Initialize new GDT table and/or IDT table, if any + // + AsmReadIdtr (&Idtr); + AsmReadGdtr (&Gdtr); + + GdtSize = (UINTN)TssDesc + + sizeof (IA32_TSS_DESCRIPTOR) * + (StackSwitchData->Ia32.StackSwitchExceptionNumber + 1) - + (UINTN)(StackSwitchData->Ia32.GdtTable); + if ((UINTN)StackSwitchData->Ia32.GdtTable != Gdtr.Base) { + CopyMem (StackSwitchData->Ia32.GdtTable, (VOID *)Gdtr.Base, Gdtr.Limit + 1); + Gdtr.Base = (UINTN)StackSwitchData->Ia32.GdtTable; + Gdtr.Limit = (UINT16)GdtSize - 1; + } + + if ((UINTN)StackSwitchData->Ia32.IdtTable != Idtr.Base) { + Idtr.Base = (UINTN)StackSwitchData->Ia32.IdtTable; + } + if (StackSwitchData->Ia32.IdtTableSize > 0) { + Idtr.Limit = (UINT16)(StackSwitchData->Ia32.IdtTableSize - 1); + } + + // + // Fixup current task descriptor. Task-state segment for current task will + // be filled by processor during task switching. + // + 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->Ia32.KnownGoodStackTop - CPU_STACK_ALIGNMENT; + StackTop = (UINTN)ALIGN_POINTER (StackTop, CPU_STACK_ALIGNMENT); + IdtTable = StackSwitchData->Ia32.IdtTable; + for (Index = 0; Index < StackSwitchData->Ia32.StackSwitchExceptionNumber; ++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->Ia32.StackSwitchExceptions[Index]; + if (Vector >= CPU_EXCEPTION_NUM || + Vector >= (Idtr.Limit + 1) / sizeof (IA32_IDT_GATE_DESCRIPTOR)) { + continue; + } + + 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->Ia32.KnownGoodStackSize; + + // + // 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->Ia32.ExceptionTssDesc - 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.
+; 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/PeiCpuException.c b/UefiCpuPkg/Library/CpuExceptionHandlerLib/PeiCpuException.c index 8d8d16ecbd..6f271983f2 100644 --- a/UefiCpuPkg/Library/CpuExceptionHandlerLib/PeiCpuException.c +++ b/UefiCpuPkg/Library/CpuExceptionHandlerLib/PeiCpuException.c @@ -177,4 +177,36 @@ RegisterCpuInterruptHandler ( ) { return EFI_UNSUPPORTED; -} \ No newline at end of file +} + +/** + Initializes all CPU exceptions entries with optional extra initializations. + + By default, this method should include all functionalities implemented by + InitializeCpuExceptionHandlers(), plus extra initialization works, if any. + This could be done by calling InitializeCpuExceptionHandlers() directly + in this method besides the extra works. + + InitData is optional and its use and content are processor arch dependent. + The typical usage of it is to convey resources which have to be reserved + elsewhere and are necessary for the extra initializations of exception. + + @param[in] VectorInfo Pointer to reserved vector list. + @param[in] InitData Pointer to data optional for extra initializations + of exception. + + @retval EFI_SUCCESS The exceptions have been successfully + initialized. + @retval EFI_INVALID_PARAMETER VectorInfo or InitData contains invalid + content. + +**/ +EFI_STATUS +EFIAPI +InitializeCpuExceptionHandlersEx ( + IN EFI_VECTOR_HANDOFF_INFO *VectorInfo OPTIONAL, + IN CPU_EXCEPTION_INIT_DATA *InitData OPTIONAL + ) +{ + return InitializeCpuExceptionHandlers (VectorInfo); +} 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/SecPeiCpuException.c b/UefiCpuPkg/Library/CpuExceptionHandlerLib/SecPeiCpuException.c index af608bffb6..13bf20d143 100644 --- a/UefiCpuPkg/Library/CpuExceptionHandlerLib/SecPeiCpuException.c +++ b/UefiCpuPkg/Library/CpuExceptionHandlerLib/SecPeiCpuException.c @@ -176,4 +176,36 @@ RegisterCpuInterruptHandler ( ) { return EFI_UNSUPPORTED; -} \ No newline at end of file +} + +/** + Initializes all CPU exceptions entries with optional extra initializations. + + By default, this method should include all functionalities implemented by + InitializeCpuExceptionHandlers(), plus extra initialization works, if any. + This could be done by calling InitializeCpuExceptionHandlers() directly + in this method besides the extra works. + + InitData is optional and its use and content are processor arch dependent. + The typical usage of it is to convey resources which have to be reserved + elsewhere and are necessary for the extra initializations of exception. + + @param[in] VectorInfo Pointer to reserved vector list. + @param[in] InitData Pointer to data optional for extra initializations + of exception. + + @retval EFI_SUCCESS The exceptions have been successfully + initialized. + @retval EFI_INVALID_PARAMETER VectorInfo or InitData contains invalid + content. + +**/ +EFI_STATUS +EFIAPI +InitializeCpuExceptionHandlersEx ( + IN EFI_VECTOR_HANDOFF_INFO *VectorInfo OPTIONAL, + IN CPU_EXCEPTION_INIT_DATA *InitData OPTIONAL + ) +{ + return InitializeCpuExceptionHandlers (VectorInfo); +} 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/SmmException.c b/UefiCpuPkg/Library/CpuExceptionHandlerLib/SmmException.c index 7414d3f773..95f4ce51ea 100644 --- a/UefiCpuPkg/Library/CpuExceptionHandlerLib/SmmException.c +++ b/UefiCpuPkg/Library/CpuExceptionHandlerLib/SmmException.c @@ -125,4 +125,36 @@ RegisterCpuInterruptHandler ( ) { return RegisterCpuInterruptHandlerWorker (InterruptType, InterruptHandler, &mExceptionHandlerData); -} \ No newline at end of file +} + +/** + Initializes all CPU exceptions entries with optional extra initializations. + + By default, this method should include all functionalities implemented by + InitializeCpuExceptionHandlers(), plus extra initialization works, if any. + This could be done by calling InitializeCpuExceptionHandlers() directly + in this method besides the extra works. + + InitData is optional and its use and content are processor arch dependent. + The typical usage of it is to convey resources which have to be reserved + elsewhere and are necessary for the extra initializations of exception. + + @param[in] VectorInfo Pointer to reserved vector list. + @param[in] InitData Pointer to data optional for extra initializations + of exception. + + @retval EFI_SUCCESS The exceptions have been successfully + initialized. + @retval EFI_INVALID_PARAMETER VectorInfo or InitData contains invalid + content. + +**/ +EFI_STATUS +EFIAPI +InitializeCpuExceptionHandlersEx ( + IN EFI_VECTOR_HANDOFF_INFO *VectorInfo OPTIONAL, + IN CPU_EXCEPTION_INIT_DATA *InitData OPTIONAL + ) +{ + return InitializeCpuExceptionHandlers (VectorInfo); +} diff --git a/UefiCpuPkg/Library/CpuExceptionHandlerLib/X64/ArchExceptionHandler.c b/UefiCpuPkg/Library/CpuExceptionHandlerLib/X64/ArchExceptionHandler.c index 65f0cff680..1dcf4277de 100644 --- a/UefiCpuPkg/Library/CpuExceptionHandlerLib/X64/ArchExceptionHandler.c +++ b/UefiCpuPkg/Library/CpuExceptionHandlerLib/X64/ArchExceptionHandler.c @@ -112,6 +112,162 @@ 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 with new stack. + @retval EFI_INVALID_PARAMETER StackSwitchData contains invalid content. + +**/ +EFI_STATUS +ArchSetupExcpetionStack ( + IN CPU_EXCEPTION_INIT_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; + + if (StackSwitchData == NULL || + StackSwitchData->Ia32.Revision != CPU_EXCEPTION_INIT_DATA_REV || + StackSwitchData->X64.KnownGoodStackTop == 0 || + StackSwitchData->X64.KnownGoodStackSize == 0 || + StackSwitchData->X64.StackSwitchExceptions == NULL || + StackSwitchData->X64.StackSwitchExceptionNumber == 0 || + StackSwitchData->X64.StackSwitchExceptionNumber > CPU_EXCEPTION_NUM || + StackSwitchData->X64.GdtTable == NULL || + StackSwitchData->X64.IdtTable == NULL || + StackSwitchData->X64.ExceptionTssDesc == NULL || + StackSwitchData->X64.ExceptionTss == 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->X64.GdtTable & (IA32_GDT_ALIGNMENT - 1)) != 0) { + return EFI_INVALID_PARAMETER; + } + + if ((UINTN)StackSwitchData->X64.ExceptionTssDesc < (UINTN)(StackSwitchData->X64.GdtTable)) { + return EFI_INVALID_PARAMETER; + } + + if (((UINTN)StackSwitchData->X64.ExceptionTssDesc + StackSwitchData->X64.ExceptionTssDescSize) > + ((UINTN)(StackSwitchData->X64.GdtTable) + StackSwitchData->X64.GdtTableSize)) { + return EFI_INVALID_PARAMETER; + } + + // + // One task gate descriptor and one task-state segment are needed. + // + if (StackSwitchData->X64.ExceptionTssDescSize < sizeof (IA32_TSS_DESCRIPTOR)) { + return EFI_INVALID_PARAMETER; + } + if (StackSwitchData->X64.ExceptionTssSize < sizeof (IA32_TASK_STATE_SEGMENT)) { + return EFI_INVALID_PARAMETER; + } + + // + // Interrupt stack table supports only 7 vectors. + // + TssDesc = StackSwitchData->X64.ExceptionTssDesc; + Tss = StackSwitchData->X64.ExceptionTss; + if (StackSwitchData->X64.StackSwitchExceptionNumber > ARRAY_SIZE (Tss->IST)) { + return EFI_INVALID_PARAMETER; + } + + // + // Initialize new GDT table and/or IDT table, if any + // + AsmReadIdtr (&Idtr); + AsmReadGdtr (&Gdtr); + + GdtSize = (UINTN)TssDesc + sizeof (IA32_TSS_DESCRIPTOR) - + (UINTN)(StackSwitchData->X64.GdtTable); + if ((UINTN)StackSwitchData->X64.GdtTable != Gdtr.Base) { + CopyMem (StackSwitchData->X64.GdtTable, (VOID *)Gdtr.Base, Gdtr.Limit + 1); + Gdtr.Base = (UINTN)StackSwitchData->X64.GdtTable; + Gdtr.Limit = (UINT16)GdtSize - 1; + } + + if ((UINTN)StackSwitchData->X64.IdtTable != Idtr.Base) { + Idtr.Base = (UINTN)StackSwitchData->X64.IdtTable; + } + if (StackSwitchData->X64.IdtTableSize > 0) { + Idtr.Limit = (UINT16)(StackSwitchData->X64.IdtTableSize - 1); + } + + // + // Fixup current task descriptor. Task-state segment for current task will + // be filled by processor during task switching. + // + 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->X64.KnownGoodStackTop - CPU_STACK_ALIGNMENT; + StackTop = (UINTN)ALIGN_POINTER (StackTop, CPU_STACK_ALIGNMENT); + IdtTable = StackSwitchData->X64.IdtTable; + for (Index = 0; Index < StackSwitchData->X64.StackSwitchExceptionNumber; ++Index) { + // + // Fixup IST + // + Tss->IST[Index] = StackTop; + StackTop -= StackSwitchData->X64.KnownGoodStackSize; + + // + // Set the IST field to enable corresponding IST + // + Vector = StackSwitchData->X64.StackSwitchExceptions[Index]; + if (Vector >= CPU_EXCEPTION_NUM || + Vector >= (Idtr.Limit + 1) / sizeof (IA32_IDT_GATE_DESCRIPTOR)) { + continue; + } + IdtTable[Vector].Bits.Reserved_0 = (UINT8)(Index + 1); + } + + // + // Publish GDT + // + AsmWriteGdtr (&Gdtr); + + // + // Load current task + // + AsmWriteTr ((UINT16)((UINTN)StackSwitchData->X64.ExceptionTssDesc - 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 -- 2.39.2