From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received-SPF: Pass (sender SPF authorized) identity=mailfrom; client-ip=192.55.52.115; helo=mga14.intel.com; envelope-from=jian.j.wang@intel.com; receiver=edk2-devel@lists.01.org Received: from mga14.intel.com (mga14.intel.com [192.55.52.115]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ml01.01.org (Postfix) with ESMTPS id 63DBF2035D10F for ; Tue, 31 Oct 2017 07:22:07 -0700 (PDT) Received: from fmsmga006.fm.intel.com ([10.253.24.20]) by fmsmga103.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 31 Oct 2017 07:25:59 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.44,324,1505804400"; d="scan'208";a="170043598" Received: from jwang36-mobl2.ccr.corp.intel.com ([10.254.212.126]) by fmsmga006.fm.intel.com with ESMTP; 31 Oct 2017 07:25:57 -0700 From: Jian J Wang To: edk2-devel@lists.01.org Cc: Star Zeng , Eric Dong , Jiewen Yao , Michael Kinney Date: Tue, 31 Oct 2017 22:24:12 +0800 Message-Id: <20171031142412.21680-4-jian.j.wang@intel.com> X-Mailer: git-send-email 2.14.1.windows.1 In-Reply-To: <20171031142412.21680-1-jian.j.wang@intel.com> References: <20171031142412.21680-1-jian.j.wang@intel.com> Subject: [PATCH 3/3] UefiCpuPkg/CpuExceptionHandlerLib: Add stack switch support X-BeenThere: edk2-devel@lists.01.org X-Mailman-Version: 2.1.22 Precedence: list List-Id: EDK II Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 31 Oct 2017 14:22:07 -0000 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). Note: Stack switch needs to allocate memory pages to be new stacks. So this functionality works only in the boot phases capable of memory allocation (besides the paging, for the sake of Stack Guard). In other words, only DXE phase can supports Stack Guard with stack switch. Cc: Star Zeng Cc: Eric Dong Cc: Jiewen Yao Cc: Michael Kinney Suggested-by: Ayellet Wolman Contributed-under: TianoCore Contribution Agreement 1.1 Signed-off-by: Jian J Wang --- .../CpuExceptionHandlerLib/CpuExceptionCommon.h | 22 ++ .../DxeCpuExceptionHandlerLib.inf | 5 + .../Library/CpuExceptionHandlerLib/DxeException.c | 19 + .../Ia32/ArchExceptionHandler.c | 135 +++++++ .../Ia32/ArchInterruptDefs.h | 136 +++++++ .../Ia32/ExceptionTssEntryAsm.nasm | 398 +++++++++++++++++++++ .../PeiCpuExceptionHandlerLib.inf | 1 + .../SecPeiCpuExceptionHandlerLib.inf | 3 + .../SmmCpuExceptionHandlerLib.inf | 1 + .../X64/ArchExceptionHandler.c | 108 ++++++ .../CpuExceptionHandlerLib/X64/ArchInterruptDefs.h | 40 +++ .../X64/ExceptionHandlerAsm.S | 12 + .../X64/ExceptionHandlerAsm.asm | 12 + .../X64/ExceptionHandlerAsm.nasm | 12 + 14 files changed, 904 insertions(+) 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..fd4a26a458 100644 --- a/UefiCpuPkg/Library/CpuExceptionHandlerLib/CpuExceptionCommon.h +++ b/UefiCpuPkg/Library/CpuExceptionHandlerLib/CpuExceptionCommon.h @@ -25,6 +25,7 @@ #include #include #include +#include #define CPU_EXCEPTION_NUM 32 #define CPU_INTERRUPT_NUM 256 @@ -288,5 +289,26 @@ CommonExceptionHandlerWorker ( IN EXCEPTION_HANDLER_DATA *ExceptionHandlerData ); +/** + Load given selector into TR register + + @param Selector Task segment selector +**/ +VOID +AsmWriteTr ( + UINT16 Selector + ); + +/** + Setup separate stack for specific exceptions. + + @param[in] IdtTable IDT table base. +**/ +VOID +EFIAPI +ArchSetupExcpetionStack ( + IN IA32_IDT_GATE_DESCRIPTOR *IdtTable + ); + #endif diff --git a/UefiCpuPkg/Library/CpuExceptionHandlerLib/DxeCpuExceptionHandlerLib.inf b/UefiCpuPkg/Library/CpuExceptionHandlerLib/DxeCpuExceptionHandlerLib.inf index f4a8d01c80..b099ef4dad 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 +48,9 @@ PeiDxeSmmCpuException.c DxeException.c +[Pcd] + gEfiMdeModulePkgTokenSpaceGuid.PcdCpuStackGuard + [Packages] MdePkg/MdePkg.dec MdeModulePkg/MdeModulePkg.dec @@ -61,3 +65,4 @@ PeCoffGetEntryPointLib MemoryAllocationLib DebugLib + HobLib diff --git a/UefiCpuPkg/Library/CpuExceptionHandlerLib/DxeException.c b/UefiCpuPkg/Library/CpuExceptionHandlerLib/DxeException.c index 31febec976..e9dcd00e02 100644 --- a/UefiCpuPkg/Library/CpuExceptionHandlerLib/DxeException.c +++ b/UefiCpuPkg/Library/CpuExceptionHandlerLib/DxeException.c @@ -16,6 +16,7 @@ #include "CpuExceptionCommon.h" #include #include +#include CONST UINTN mDoFarReturnFlag = 0; @@ -155,6 +156,24 @@ InitializeCpuInterruptHandlers ( UpdateIdtTable (IdtTable, &TemplateMap, &mExceptionHandlerData); + if (PcdGetBool (PcdCpuStackGuard)) { + // + // Stack Guard works with the support of page table established and + // memory management. So we have to exclude those boot modes without + // them. + // + switch (GetBootModeHob()) { + case BOOT_ON_FLASH_UPDATE: + case BOOT_IN_RECOVERY_MODE: + case BOOT_ON_S3_RESUME: + break; + + default: + ArchSetupExcpetionStack (IdtTable); + break; + } + } + // // Load Interrupt Descriptor Table // diff --git a/UefiCpuPkg/Library/CpuExceptionHandlerLib/Ia32/ArchExceptionHandler.c b/UefiCpuPkg/Library/CpuExceptionHandlerLib/Ia32/ArchExceptionHandler.c index f2c39eb193..3d41df75a5 100644 --- a/UefiCpuPkg/Library/CpuExceptionHandlerLib/Ia32/ArchExceptionHandler.c +++ b/UefiCpuPkg/Library/CpuExceptionHandlerLib/Ia32/ArchExceptionHandler.c @@ -14,6 +14,19 @@ #include "CpuExceptionCommon.h" +// +// List of exceptions needing separate stack +// +STATIC IA32_EXCEPTION_TS_ENTRY mExceptionsWithStack[] = { + {6, ExceptionTaskSwtichEntry6}, //#UD: Invalid Opcode Exception + {8, ExceptionTaskSwtichEntry8}, //#DF: Double Fault Exception + {12, ExceptionTaskSwtichEntry12}, //#SS: Stack Fault Exception + {13, ExceptionTaskSwtichEntry13}, //#GP: General Protection Exception + {14, ExceptionTaskSwtichEntry14}, //#PF: Page-Fault Exception + {17, ExceptionTaskSwtichEntry17}, //#AC: Alignment Check Exception + {18, ExceptionTaskSwtichEntry18} //#MC: Machine-Check Exception +}; + /** Return address map of exception handler template so that C code can generate exception tables. @@ -107,6 +120,128 @@ ArchRestoreExceptionContext ( SystemContext.SystemContextIa32->ExceptionData = ReservedVectors[ExceptionType].ExceptionData; } +/** + Setup separate stack for specific exceptions. + + @param[in] IdtTable IDT table base. +**/ +VOID +EFIAPI +ArchSetupExcpetionStack ( + IN IA32_IDT_GATE_DESCRIPTOR *IdtTable + ) +{ + VOID *NewGdt; + IA32_DESCRIPTOR GdtDesc; + UINTN OldGdtSize; + TSS_ENTRIES *TssEntry; + IA32_TSS_DESCRIPTOR *TssDesc; + IA32_TASK_STATE_SEGMENT *Tss; + UINTN StackBase; + UINTN StackTop; + UINTN StackSize; + UINTN Index; + UINTN Vector; + UINTN TssBase; + + // + // Allocate Runtime Data for the GDT + // + AsmReadGdtr(&GdtDesc); + OldGdtSize = GdtDesc.Limit + 1; + NewGdt = AllocateRuntimeZeroPool(OldGdtSize + sizeof(TSS_ENTRIES) + + IA32_GDT_ALIGNMENT); + if (NewGdt == NULL) { + return; + } + NewGdt = ALIGN_POINTER (NewGdt, IA32_GDT_ALIGNMENT); + + // + // Initialize new GDT entries + // + CopyMem(NewGdt, (VOID *)GdtDesc.Base, OldGdtSize); + GdtDesc.Base = (UINTN)(VOID*)NewGdt; + GdtDesc.Limit = (UINT16)(OldGdtSize + TSS_OFFSET - 1); + + // + // Reserve statck memory for given exceptions + // + StackSize = ARRAY_SIZE (mExceptionsWithStack) * EXCEPTION_STACK_SIZE; + StackSize = EFI_PAGES_TO_SIZE (EFI_SIZE_TO_PAGES (StackSize)); + StackBase = (UINT64)(UINTN)AllocatePages (EFI_SIZE_TO_PAGES (StackSize)); + if (StackBase == 0) { + FreePool (NewGdt); + return; + } + + // + // Fixup TSS descriptors and segments + // + TssEntry = (VOID *)(GdtDesc.Base + OldGdtSize); + + TssBase = (UINTN)(VOID *)&TssEntry->Tss; + TssEntry->TssSeg.Limit15_0 = sizeof(IA32_TASK_STATE_SEGMENT) - 1; + TssEntry->TssSeg.Base15_0 = (UINT16)TssBase; + TssEntry->TssSeg.Base23_16 = (UINT8)(TssBase >> 16); + TssEntry->TssSeg.Type = IA32_GDT_TYPE_TSS; + TssEntry->TssSeg.Limit19_16_and_flags = 0; + TssEntry->TssSeg.Base31_24 = (UINT8)(TssBase >> 24); + + StackTop = StackBase + StackSize - CPU_STACK_ALIGNMENT; + StackTop = (UINTN)ALIGN_POINTER (StackTop, CPU_STACK_ALIGNMENT); + for (Index = 0; Index < ARRAY_SIZE (mExceptionsWithStack); ++Index) { + // + // Fixup TSS descriptor + // + TssBase = (UINTN)(VOID *)&TssEntry->ExceptionTss[Index]; + TssDesc = &TssEntry->ExceptionTssSeg[Index]; + + TssDesc->Limit15_0 = sizeof(IA32_TASK_STATE_SEGMENT) - 1; + TssDesc->Base15_0 = (UINT16)TssBase; + TssDesc->Base23_16 = (UINT8)(TssBase >> 16); + TssDesc->Type = IA32_GDT_TYPE_TSS; + TssDesc->Limit19_16_and_flags = 0; + TssDesc->Base31_24 = (UINT8)(TssBase >> 24); + + // + // Fixup TSS + // + Tss = &TssEntry->ExceptionTss[Index]; + Tss->CR3 = AsmReadCr3(); + Tss->EIP = (UINT32)mExceptionsWithStack[Index].EntryPoint; + Tss->EFLAGS = 0x2; + Tss->ESP = StackTop; + Tss->ES = AsmReadEs(); + Tss->CS = AsmReadCs(); + Tss->SS = AsmReadSs(); + Tss->DS = AsmReadDs(); + Tss->FS = AsmReadFs(); + Tss->GS = AsmReadGs(); + StackTop -= EXCEPTION_STACK_SIZE; + + // + // Change specified exceptions in IDT to use TSS + // + Vector = mExceptionsWithStack[Index].Vector; + + IdtTable[Vector].Bits.OffsetLow = 0; + IdtTable[Vector].Bits.Selector = OldGdtSize + EXCEPTION_TSS_SEL(Index); + IdtTable[Vector].Bits.Reserved_0 = 0; + IdtTable[Vector].Bits.GateType = IA32_IDT_GATE_TYPE_TASK; + IdtTable[Vector].Bits.OffsetHigh = 0; + } + + // + // Publish the changes + // + AsmWriteGdtr(&GdtDesc); + + // + // Load task register + // + AsmWriteTr ((UINT16)(OldGdtSize + TSS_SEL)); +} + /** Display processor context. diff --git a/UefiCpuPkg/Library/CpuExceptionHandlerLib/Ia32/ArchInterruptDefs.h b/UefiCpuPkg/Library/CpuExceptionHandlerLib/Ia32/ArchInterruptDefs.h index a8d3556a80..77cc6f9919 100644 --- a/UefiCpuPkg/Library/CpuExceptionHandlerLib/Ia32/ArchInterruptDefs.h +++ b/UefiCpuPkg/Library/CpuExceptionHandlerLib/Ia32/ArchInterruptDefs.h @@ -41,4 +41,140 @@ typedef struct { UINT8 HookAfterStubHeaderCode[HOOKAFTER_STUB_SIZE]; } RESERVED_VECTORS_DATA; +#pragma pack (1) + +#define EXCEPTION_LIST_MAX 7 +#define EXCEPTION_STACK_SIZE EFI_PAGE_SIZE +#define IA32_GDT_TYPE_TSS 0x89 +#define IA32_GDT_ALIGNMENT 8 + +// +// IA32 TSS Definition +// +typedef struct { + UINT16 PreviousTaskLink; // 00 + UINT16 Reserved_2; + UINT32 ESP0; // 04 + UINT16 SS0; // 08 + UINT16 Reserved_10; + UINT32 ESP1; // 0C + UINT16 SS1; // 10 + UINT16 Reserved_18; + UINT32 ESP2; // 14 + UINT16 SS2; // 18 + UINT16 Reserved_26; + UINT32 CR3; // 1C + UINT32 EIP; // 20 + UINT32 EFLAGS; // 24 + UINT32 EAX; // 28 + UINT32 ECX; // 2C + UINT32 EDX; // 30 + UINT32 EBX; // 34 + UINT32 ESP; // 38 + UINT32 EBP; + UINT32 ESI; + UINT32 EDI; + UINT16 ES; + UINT16 Reserved_74; + UINT16 CS; + UINT16 Reserved_78; + UINT16 SS; + UINT16 Reserved_82; + UINT16 DS; + UINT16 Reserved_86; + UINT16 FS; + UINT16 Reserved_90; + UINT16 GS; + UINT16 Reserved_94; + UINT16 LDTSegmentSelector; + UINT16 Reserved_98; + UINT16 T; + UINT16 IOMapBaseAddress; +} IA32_TASK_STATE_SEGMENT; + +typedef struct { + UINT16 Limit15_0; + UINT16 Base15_0; + UINT8 Base23_16; + UINT8 Type; + UINT8 Limit19_16_and_flags; + UINT8 Base31_24; +} IA32_TSS_DESCRIPTOR; + +typedef struct { + IA32_TSS_DESCRIPTOR TssSeg; + IA32_TSS_DESCRIPTOR ExceptionTssSeg[EXCEPTION_LIST_MAX]; + IA32_TASK_STATE_SEGMENT Tss; + IA32_TASK_STATE_SEGMENT ExceptionTss[EXCEPTION_LIST_MAX]; +} TSS_ENTRIES; + +#pragma pack () + +#define TSS_SEL OFFSET_OF (TSS_ENTRIES, TssSeg) +#define EXCEPTION_TSS_SEL(n) OFFSET_OF (TSS_ENTRIES, ExceptionTssSeg[n]) +#define TSS_OFFSET OFFSET_OF (TSS_ENTRIES, Tss) + +typedef VOID (*EXCEPTION_ENTRY) (VOID); + +typedef struct { + UINTN Vector; + EXCEPTION_ENTRY EntryPoint; +} IA32_EXCEPTION_TS_ENTRY; + +/** + Exception handling entry through task gate for exception #UD. + **/ +VOID +ExceptionTaskSwtichEntry6 ( + VOID + ); + +/** + Exception handling entry through task gate for exception #DF. + **/ +VOID +ExceptionTaskSwtichEntry8 ( + VOID + ); + +/** + Exception handling entry through task gate for exception #SS. + **/ +VOID +ExceptionTaskSwtichEntry12 ( + VOID + ); + +/** + Exception handling entry through task gate for exception #GP. + **/ +VOID +ExceptionTaskSwtichEntry13 ( + VOID + ); + +/** + Exception handling entry through task gate for exception #PF. + **/ +VOID +ExceptionTaskSwtichEntry14 ( + VOID + ); + +/** + Exception handling entry through task gate for exception #AC. + **/ +VOID +ExceptionTaskSwtichEntry17 ( + VOID + ); + +/** + Exception handling entry through task gate for exception #MC. + **/ +VOID +ExceptionTaskSwtichEntry18 ( + VOID + ); + #endif diff --git a/UefiCpuPkg/Library/CpuExceptionHandlerLib/Ia32/ExceptionTssEntryAsm.nasm b/UefiCpuPkg/Library/CpuExceptionHandlerLib/Ia32/ExceptionTssEntryAsm.nasm new file mode 100644 index 0000000000..dbfbcfcf51 --- /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 +; +%macro DefExceptionTaskSwtichEntry 1 +%%DoIret: + iretd + +global ASM_PFX(ExceptionTaskSwtichEntry%1) +ASM_PFX(ExceptionTaskSwtichEntry%1): + db 0x6a ; push #VectorNum + db %1 ; VectorNum + mov eax, ASM_PFX(CommonTaskSwtichEntryPoint) + call eax + mov esp, eax ; Restore stack top + jmp %%DoIret +%endmacro + +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 + + ; +---------------------+ + ; +; +; Get TSS of interrupted task +; + 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 + +;------------------------------------------------------------------------------ +; VOID +; AsmWriteTr ( +; UINT16 Selector +; ); +;------------------------------------------------------------------------------ +global ASM_PFX(AsmWriteTr) +ASM_PFX(AsmWriteTr): + mov eax, [esp+4] + ltr ax + ret + +DefExceptionTaskSwtichEntry 6 +DefExceptionTaskSwtichEntry 8 +DefExceptionTaskSwtichEntry 12 +DefExceptionTaskSwtichEntry 13 +DefExceptionTaskSwtichEntry 14 +DefExceptionTaskSwtichEntry 17 +DefExceptionTaskSwtichEntry 18 + 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..adb415ba5a 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 @@ -57,3 +58,5 @@ PrintLib LocalApicLib PeCoffGetEntryPointLib + MemoryAllocationLib + 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..24f2a8486a 100644 --- a/UefiCpuPkg/Library/CpuExceptionHandlerLib/X64/ArchExceptionHandler.c +++ b/UefiCpuPkg/Library/CpuExceptionHandlerLib/X64/ArchExceptionHandler.c @@ -14,6 +14,19 @@ #include "CpuExceptionCommon.h" +// +// List of exceptions needing separate stack +// +STATIC UINTN mExceptionsWithStack[] = { + 6, //#UD: Invalid Opcode Exception + 8, //#DF: Double Fault Exception + 12, //#SS: Stack Fault Exception + 13, //#GP: General Protection Exception + 14, //#PF: Page-Fault Exception + 17, //#AC: Alignment Check Exception + 18 //#MC: Machine-Check Exception + }; + /** Return address map of exception handler template so that C code can generate exception tables. @@ -112,6 +125,101 @@ ArchRestoreExceptionContext ( SystemContext.SystemContextX64->ExceptionData = ReservedVectors[ExceptionType].ExceptionData; } +/** + Setup separate stack for specific exceptions. + + @param[in] IdtTable IDT table base. +**/ +VOID +EFIAPI +ArchSetupExcpetionStack ( + IN IA32_IDT_GATE_DESCRIPTOR *IdtTable + ) +{ + VOID *NewGdt; + IA32_DESCRIPTOR GdtDesc; + UINTN OldGdtSize; + TSS_ENTRIES *TssEntry; + UINTN StackBase; + UINTN StackTop; + UINTN StackSize; + UINTN TssBase; + UINTN Index; + + // + // Allocate Runtime Data for the GDT + // + AsmReadGdtr(&GdtDesc); + OldGdtSize = GdtDesc.Limit + 1; + NewGdt = AllocateRuntimeZeroPool(OldGdtSize + sizeof(TSS_ENTRIES) + + IA32_GDT_ALIGNMENT); + if (NewGdt == NULL) { + return; + } + NewGdt = ALIGN_POINTER (NewGdt, IA32_GDT_ALIGNMENT); + + // + // Initialize new GDT entries + // + CopyMem(NewGdt, (VOID *)GdtDesc.Base, OldGdtSize); + GdtDesc.Base = (UINTN)(VOID*)NewGdt; + GdtDesc.Limit = (UINT16)(OldGdtSize + TSS_OFFSET - 1); + + // + // Reserve statck memory for supported exceptions + // + StackSize = ARRAY_SIZE (mExceptionsWithStack) * EXCEPTION_STACK_SIZE; + StackSize = EFI_PAGES_TO_SIZE (EFI_SIZE_TO_PAGES (StackSize)); + StackBase = (UINT64)AllocatePages (EFI_SIZE_TO_PAGES (StackSize)); + if (StackBase == 0) { + FreePool (NewGdt); + return; + } + + // + // Fixup TSS descriptors + // + TssEntry = (VOID *)(GdtDesc.Base + OldGdtSize); + TssBase = (UINTN)(VOID *)&TssEntry->Tss; + + TssEntry->TssSeg.Limit15_0 = sizeof(IA32_TASK_STATE_SEGMENT) - 1; + TssEntry->TssSeg.Base15_0 = (UINT16)TssBase; + TssEntry->TssSeg.Base23_16 = (UINT8)(TssBase >> 16); + TssEntry->TssSeg.Type = IA32_GDT_TYPE_TSS; + TssEntry->TssSeg.Limit19_16_and_flags = 0; + TssEntry->TssSeg.Base31_24 = (UINT8)(TssBase >> 24); + TssEntry->TssSeg.Base63_32 = (UINT32)(TssBase >> 32); + TssEntry->TssSeg.Reserved = 0; + + // + // Enable Interrupt Stack Table (IST) for each required exception + // + StackTop = StackBase + StackSize - CPU_STACK_ALIGNMENT; + StackTop = (UINTN)ALIGN_POINTER (StackTop, CPU_STACK_ALIGNMENT); + for (Index = 0; Index < ARRAY_SIZE (mExceptionsWithStack); ++Index) { + // + // Fixup TSS + // + TssEntry->Tss.IST[Index] = StackTop; + StackTop -= EXCEPTION_STACK_SIZE; + + // + // Set the IST field to 1 to enable corresponding IST + // + IdtTable[mExceptionsWithStack[Index]].Bits.Reserved_0 = (UINT8)(Index + 1); + } + + // + // Publish the changes + // + AsmWriteGdtr(&GdtDesc); + + // + // Load task register + // + AsmWriteTr ((UINT16)(OldGdtSize + TSS_SEL)); +} + /** Display CPU information. diff --git a/UefiCpuPkg/Library/CpuExceptionHandlerLib/X64/ArchInterruptDefs.h b/UefiCpuPkg/Library/CpuExceptionHandlerLib/X64/ArchInterruptDefs.h index 906480134a..5a913bae7b 100644 --- a/UefiCpuPkg/Library/CpuExceptionHandlerLib/X64/ArchInterruptDefs.h +++ b/UefiCpuPkg/Library/CpuExceptionHandlerLib/X64/ArchInterruptDefs.h @@ -43,4 +43,44 @@ typedef struct { UINT8 HookAfterStubHeaderCode[HOOKAFTER_STUB_SIZE]; } RESERVED_VECTORS_DATA; +#pragma pack (1) + +#define EXCEPTION_LIST_MAX 7 +#define EXCEPTION_STACK_SIZE EFI_PAGE_SIZE +#define IA32_GDT_TYPE_TSS 0x89 +#define IA32_GDT_ALIGNMENT 8 + +typedef struct { + UINT32 Reserved_0; + UINT64 RSP0; + UINT64 RSP1; + UINT64 RSP2; + UINT64 Reserved_28; + UINT64 IST[7]; + UINT64 Reserved_92; + UINT16 Reserved_100; + UINT16 IOMapBaseAddress; +} IA32_TASK_STATE_SEGMENT; + +typedef struct { + UINT16 Limit15_0; + UINT16 Base15_0; + UINT8 Base23_16; + UINT8 Type; + UINT8 Limit19_16_and_flags; + UINT8 Base31_24; + UINT32 Base63_32; + UINT32 Reserved; +} IA32_TSS_DESCRIPTOR; + +typedef struct { + IA32_TSS_DESCRIPTOR TssSeg; + IA32_TASK_STATE_SEGMENT Tss; +} TSS_ENTRIES; + +#pragma pack () + +#define TSS_SEL OFFSET_OF (TSS_ENTRIES, TssSeg) +#define TSS_OFFSET OFFSET_OF (TSS_ENTRIES, Tss) + #endif diff --git a/UefiCpuPkg/Library/CpuExceptionHandlerLib/X64/ExceptionHandlerAsm.S b/UefiCpuPkg/Library/CpuExceptionHandlerLib/X64/ExceptionHandlerAsm.S index edd363cdaa..bdaf132cf5 100644 --- a/UefiCpuPkg/Library/CpuExceptionHandlerLib/X64/ExceptionHandlerAsm.S +++ b/UefiCpuPkg/Library/CpuExceptionHandlerLib/X64/ExceptionHandlerAsm.S @@ -429,6 +429,18 @@ ASM_PFX(AsmVectorNumFixup): popq %rbp ret +#------------------------------------------------------------------------------ +# VOID +# AsmWriteTr ( +# UINT16 Selector +# ); +#------------------------------------------------------------------------------ +ASM_GLOBAL ASM_PFX(AsmWriteTr) +ASM_PFX(AsmWriteTr): + movl %ecx, %eax + ltrw %ax + ret + #END diff --git a/UefiCpuPkg/Library/CpuExceptionHandlerLib/X64/ExceptionHandlerAsm.asm b/UefiCpuPkg/Library/CpuExceptionHandlerLib/X64/ExceptionHandlerAsm.asm index 726c64a140..aec56ef4bf 100644 --- a/UefiCpuPkg/Library/CpuExceptionHandlerLib/X64/ExceptionHandlerAsm.asm +++ b/UefiCpuPkg/Library/CpuExceptionHandlerLib/X64/ExceptionHandlerAsm.asm @@ -386,4 +386,16 @@ AsmVectorNumFixup PROC ret AsmVectorNumFixup ENDP +;------------------------------------------------------------------------------ +; VOID +; AsmWriteTr ( +; UINT16 Selector +; ); +;------------------------------------------------------------------------------ +AsmWriteTr PROC PUBLIC + mov eax, ecx + ltr ax + ret +AsmWriteTr ENDP + END diff --git a/UefiCpuPkg/Library/CpuExceptionHandlerLib/X64/ExceptionHandlerAsm.nasm b/UefiCpuPkg/Library/CpuExceptionHandlerLib/X64/ExceptionHandlerAsm.nasm index ba8993d84b..1e2ac411b0 100644 --- a/UefiCpuPkg/Library/CpuExceptionHandlerLib/X64/ExceptionHandlerAsm.nasm +++ b/UefiCpuPkg/Library/CpuExceptionHandlerLib/X64/ExceptionHandlerAsm.nasm @@ -385,3 +385,15 @@ ASM_PFX(AsmVectorNumFixup): mov [rcx + (@VectorNum - HookAfterStubHeaderBegin)], al ret +;------------------------------------------------------------------------------ +; VOID +; AsmWriteTr ( +; UINT16 Selector +; ); +;------------------------------------------------------------------------------ +global ASM_PFX(AsmWriteTr) +ASM_PFX(AsmWriteTr): + mov eax, ecx + ltr ax + ret + -- 2.14.1.windows.1