; $Id: PATMA.asm 40007 2012-02-06 11:16:59Z vboxsync $ ;; @file ; PATM Assembly Routines. ; ; Copyright (C) 2006-2007 Oracle Corporation ; ; This file is part of VirtualBox Open Source Edition (OSE), as ; available from http://www.virtualbox.org. This file is free software; ; you can redistribute it and/or modify it under the terms of the GNU ; General Public License (GPL) as published by the Free Software ; Foundation, in version 2 as it comes in the "COPYING" file of the ; VirtualBox OSE distribution. VirtualBox OSE is distributed in the ; hope that it will be useful, but WITHOUT ANY WARRANTY of any kind. ; ;; ; @note This method has problems in theory. If we fault for any reason, then we won't be able to restore ; the guest's context properly!! ; E.g if one of the push instructions causes a fault or SS isn't wide open and our patch GC state accesses aren't valid. ; @assumptions ; - Enough stack for a few pushes ; - The SS selector has base 0 and limit 0xffffffff ; ; @todo stack probing is currently hardcoded and not present everywhere (search for 'probe stack') ;******************************************************************************* ;* Header Files * ;******************************************************************************* %include "VBox/asmdefs.mac" %include "VBox/err.mac" %include "iprt/x86.mac" %include "VBox/vmm/vm.mac" %include "PATMA.mac" %ifdef DEBUG ; Noisy, but useful for debugging certain problems ;;;%define PATM_LOG_PATCHINSTR ;;%define PATM_LOG_PATCHIRET %endif BEGINCONST %ifdef RT_ARCH_AMD64 BITS 32 ; switch to 32-bit mode (x86). %endif %ifdef VBOX_WITH_STATISTICS ; ; Patch call statistics ; BEGINPROC PATMStats PATMStats_Start: mov dword [ss:PATM_INTERRUPTFLAG], 0 pushf inc dword [ss:PATM_ALLPATCHCALLS] inc dword [ss:PATM_PERPATCHCALLS] popf mov dword [ss:PATM_INTERRUPTFLAG], 1 PATMStats_End: ENDPROC PATMStats ; Patch record for statistics GLOBALNAME PATMStatsRecord RTCCPTR_DEF PATMStats_Start DD 0 DD 0 DD 0 DD PATMStats_End - PATMStats_Start DD 4 DD PATM_INTERRUPTFLAG DD 0 DD PATM_ALLPATCHCALLS DD 0 DD PATM_PERPATCHCALLS DD 0 DD PATM_INTERRUPTFLAG DD 0 DD 0ffffffffh %endif ; ; Set PATM_INTERRUPTFLAG ; BEGINPROC PATMSetPIF PATMSetPIF_Start: mov dword [ss:PATM_INTERRUPTFLAG], 1 PATMSetPIF_End: ENDPROC PATMSetPIF SECTION .data ; Patch record for setting PATM_INTERRUPTFLAG GLOBALNAME PATMSetPIFRecord RTCCPTR_DEF PATMSetPIF_Start DD 0 DD 0 DD 0 DD PATMSetPIF_End - PATMSetPIF_Start DD 1 DD PATM_INTERRUPTFLAG DD 0 DD 0ffffffffh SECTION .text ; ; Clear PATM_INTERRUPTFLAG ; BEGINPROC PATMClearPIF PATMClearPIF_Start: ; probe stack here as we can't recover from page faults later on not dword [esp-64] not dword [esp-64] mov dword [ss:PATM_INTERRUPTFLAG], 0 PATMClearPIF_End: ENDPROC PATMClearPIF SECTION .data ; Patch record for clearing PATM_INTERRUPTFLAG GLOBALNAME PATMClearPIFRecord RTCCPTR_DEF PATMClearPIF_Start DD 0 DD 0 DD 0 DD PATMClearPIF_End - PATMClearPIF_Start DD 1 DD PATM_INTERRUPTFLAG DD 0 DD 0ffffffffh SECTION .text ; ; Clear PATM_INHIBITIRQADDR and fault if IF=0 ; BEGINPROC PATMClearInhibitIRQFaultIF0 PATMClearInhibitIRQFaultIF0_Start: mov dword [ss:PATM_INTERRUPTFLAG], 0 mov dword [ss:PATM_INHIBITIRQADDR], 0 pushf test dword [ss:PATM_VMFLAGS], X86_EFL_IF jz PATMClearInhibitIRQFaultIF0_Fault ; if interrupts are pending, then we must go back to the host context to handle them! test dword [ss:PATM_VM_FORCEDACTIONS], VMCPU_FF_INTERRUPT_APIC | VMCPU_FF_INTERRUPT_PIC | VMCPU_FF_TIMER | VMCPU_FF_REQUEST jz PATMClearInhibitIRQFaultIF0_Continue ; Go to our hypervisor trap handler to dispatch the pending irq mov dword [ss:PATM_TEMP_EAX], eax mov dword [ss:PATM_TEMP_ECX], ecx mov dword [ss:PATM_TEMP_EDI], edi mov dword [ss:PATM_TEMP_RESTORE_FLAGS], PATM_RESTORE_EAX | PATM_RESTORE_ECX | PATM_RESTORE_EDI mov eax, PATM_ACTION_DISPATCH_PENDING_IRQ lock or dword [ss:PATM_PENDINGACTION], eax mov ecx, PATM_ACTION_MAGIC mov edi, PATM_NEXTINSTRADDR popfd ; restore flags we pushed above (the or instruction changes the flags as well) db 0fh, 0bh ; illegal instr (hardcoded assumption in PATMHandleIllegalInstrTrap) ; does not return PATMClearInhibitIRQFaultIF0_Fault: popf mov dword [ss:PATM_INTERRUPTFLAG], 1 PATM_INT3 PATMClearInhibitIRQFaultIF0_Continue: popf mov dword [ss:PATM_INTERRUPTFLAG], 1 PATMClearInhibitIRQFaultIF0_End: ENDPROC PATMClearInhibitIRQFaultIF0 SECTION .data ; Patch record for clearing PATM_INHIBITIRQADDR GLOBALNAME PATMClearInhibitIRQFaultIF0Record RTCCPTR_DEF PATMClearInhibitIRQFaultIF0_Start DD 0 DD 0 DD 0 DD PATMClearInhibitIRQFaultIF0_End - PATMClearInhibitIRQFaultIF0_Start DD 12 DD PATM_INTERRUPTFLAG DD 0 DD PATM_INHIBITIRQADDR DD 0 DD PATM_VMFLAGS DD 0 DD PATM_VM_FORCEDACTIONS DD 0 DD PATM_TEMP_EAX DD 0 DD PATM_TEMP_ECX DD 0 DD PATM_TEMP_EDI DD 0 DD PATM_TEMP_RESTORE_FLAGS DD 0 DD PATM_PENDINGACTION DD 0 DD PATM_NEXTINSTRADDR DD 0 DD PATM_INTERRUPTFLAG DD 0 DD PATM_INTERRUPTFLAG DD 0 DD 0ffffffffh SECTION .text ; ; Clear PATM_INHIBITIRQADDR and continue if IF=0 (duplicated function only; never jump back to guest code afterwards!!) ; BEGINPROC PATMClearInhibitIRQContIF0 PATMClearInhibitIRQContIF0_Start: mov dword [ss:PATM_INTERRUPTFLAG], 0 mov dword [ss:PATM_INHIBITIRQADDR], 0 pushf test dword [ss:PATM_VMFLAGS], X86_EFL_IF jz PATMClearInhibitIRQContIF0_Continue ; if interrupts are pending, then we must go back to the host context to handle them! test dword [ss:PATM_VM_FORCEDACTIONS], VMCPU_FF_INTERRUPT_APIC | VMCPU_FF_INTERRUPT_PIC | VMCPU_FF_TIMER | VMCPU_FF_REQUEST jz PATMClearInhibitIRQContIF0_Continue ; Go to our hypervisor trap handler to dispatch the pending irq mov dword [ss:PATM_TEMP_EAX], eax mov dword [ss:PATM_TEMP_ECX], ecx mov dword [ss:PATM_TEMP_EDI], edi mov dword [ss:PATM_TEMP_RESTORE_FLAGS], PATM_RESTORE_EAX | PATM_RESTORE_ECX | PATM_RESTORE_EDI mov eax, PATM_ACTION_DISPATCH_PENDING_IRQ lock or dword [ss:PATM_PENDINGACTION], eax mov ecx, PATM_ACTION_MAGIC mov edi, PATM_NEXTINSTRADDR popfd ; restore flags we pushed above (the or instruction changes the flags as well) db 0fh, 0bh ; illegal instr (hardcoded assumption in PATMHandleIllegalInstrTrap) ; does not return PATMClearInhibitIRQContIF0_Continue: popf mov dword [ss:PATM_INTERRUPTFLAG], 1 PATMClearInhibitIRQContIF0_End: ENDPROC PATMClearInhibitIRQContIF0 SECTION .data ; Patch record for clearing PATM_INHIBITIRQADDR GLOBALNAME PATMClearInhibitIRQContIF0Record RTCCPTR_DEF PATMClearInhibitIRQContIF0_Start DD 0 DD 0 DD 0 DD PATMClearInhibitIRQContIF0_End - PATMClearInhibitIRQContIF0_Start DD 11 DD PATM_INTERRUPTFLAG DD 0 DD PATM_INHIBITIRQADDR DD 0 DD PATM_VMFLAGS DD 0 DD PATM_VM_FORCEDACTIONS DD 0 DD PATM_TEMP_EAX DD 0 DD PATM_TEMP_ECX DD 0 DD PATM_TEMP_EDI DD 0 DD PATM_TEMP_RESTORE_FLAGS DD 0 DD PATM_PENDINGACTION DD 0 DD PATM_NEXTINSTRADDR DD 0 DD PATM_INTERRUPTFLAG DD 0 DD 0ffffffffh SECTION .text BEGINPROC PATMCliReplacement PATMCliStart: mov dword [ss:PATM_INTERRUPTFLAG], 0 pushf %ifdef PATM_LOG_PATCHINSTR push eax push ecx mov eax, PATM_ACTION_LOG_CLI lock or dword [ss:PATM_PENDINGACTION], eax mov ecx, PATM_ACTION_MAGIC db 0fh, 0bh ; illegal instr (hardcoded assumption in PATMHandleIllegalInstrTrap) pop ecx pop eax %endif and dword [ss:PATM_VMFLAGS], ~X86_EFL_IF popf mov dword [ss:PATM_INTERRUPTFLAG], 1 DB 0xE9 PATMCliJump: DD PATM_JUMPDELTA PATMCliEnd: ENDPROC PATMCliReplacement SECTION .data ; Patch record for 'cli' GLOBALNAME PATMCliRecord RTCCPTR_DEF PATMCliStart DD PATMCliJump - PATMCliStart DD 0 DD 0 DD PATMCliEnd - PATMCliStart %ifdef PATM_LOG_PATCHINSTR DD 4 %else DD 3 %endif DD PATM_INTERRUPTFLAG DD 0 %ifdef PATM_LOG_PATCHINSTR DD PATM_PENDINGACTION DD 0 %endif DD PATM_VMFLAGS DD 0 DD PATM_INTERRUPTFLAG DD 0 DD 0ffffffffh SECTION .text BEGINPROC PATMStiReplacement PATMStiStart: mov dword [ss:PATM_INTERRUPTFLAG], 0 mov dword [ss:PATM_INHIBITIRQADDR], PATM_NEXTINSTRADDR pushf %ifdef PATM_LOG_PATCHINSTR push eax push ecx mov eax, PATM_ACTION_LOG_STI lock or dword [ss:PATM_PENDINGACTION], eax mov ecx, PATM_ACTION_MAGIC db 0fh, 0bh ; illegal instr (hardcoded assumption in PATMHandleIllegalInstrTrap) pop ecx pop eax %endif or dword [ss:PATM_VMFLAGS], X86_EFL_IF popf mov dword [ss:PATM_INTERRUPTFLAG], 1 PATMStiEnd: ENDPROC PATMStiReplacement SECTION .data ; Patch record for 'sti' GLOBALNAME PATMStiRecord RTCCPTR_DEF PATMStiStart DD 0 DD 0 DD 0 DD PATMStiEnd - PATMStiStart %ifdef PATM_LOG_PATCHINSTR DD 6 %else DD 5 %endif DD PATM_INTERRUPTFLAG DD 0 DD PATM_INHIBITIRQADDR DD 0 DD PATM_NEXTINSTRADDR DD 0 %ifdef PATM_LOG_PATCHINSTR DD PATM_PENDINGACTION DD 0 %endif DD PATM_VMFLAGS DD 0 DD PATM_INTERRUPTFLAG DD 0 DD 0ffffffffh SECTION .text ; ; Trampoline code for trap entry (without error code on the stack) ; ; esp + 32 - GS (V86 only) ; esp + 28 - FS (V86 only) ; esp + 24 - DS (V86 only) ; esp + 20 - ES (V86 only) ; esp + 16 - SS (if transfer to inner ring) ; esp + 12 - ESP (if transfer to inner ring) ; esp + 8 - EFLAGS ; esp + 4 - CS ; esp - EIP ; BEGINPROC PATMTrapEntry PATMTrapEntryStart: mov dword [ss:PATM_INTERRUPTFLAG], 0 pushf %ifdef PATM_LOG_PATCHIRET push eax push ecx push edx lea edx, dword [ss:esp+12+4] ;3 dwords + pushed flags -> iret eip mov eax, PATM_ACTION_LOG_GATE_ENTRY lock or dword [ss:PATM_PENDINGACTION], eax mov ecx, PATM_ACTION_MAGIC db 0fh, 0bh ; illegal instr (hardcoded assumption in PATMHandleIllegalInstrTrap) pop edx pop ecx pop eax %endif test dword [esp+12], X86_EFL_VM jnz PATMTrapNoRing1 ; make sure the saved CS selector for ring 1 is made 0 test dword [esp+8], 2 jnz PATMTrapNoRing1 test dword [esp+8], 1 jz PATMTrapNoRing1 and dword [esp+8], dword ~1 ; yasm / nasm dword PATMTrapNoRing1: ; correct EFLAGS on the stack to include the current IOPL push eax mov eax, dword [ss:PATM_VMFLAGS] and eax, X86_EFL_IOPL and dword [esp+16], ~X86_EFL_IOPL ; esp+16 = eflags = esp+8+4(efl)+4(eax) or dword [esp+16], eax pop eax popf mov dword [ss:PATM_INTERRUPTFLAG], 1 DB 0xE9 PATMTrapEntryJump: DD PATM_JUMPDELTA PATMTrapEntryEnd: ENDPROC PATMTrapEntry SECTION .data ; Patch record for trap gate entrypoint GLOBALNAME PATMTrapEntryRecord RTCCPTR_DEF PATMTrapEntryStart DD PATMTrapEntryJump - PATMTrapEntryStart DD 0 DD 0 DD PATMTrapEntryEnd - PATMTrapEntryStart %ifdef PATM_LOG_PATCHIRET DD 4 %else DD 3 %endif DD PATM_INTERRUPTFLAG DD 0 %ifdef PATM_LOG_PATCHIRET DD PATM_PENDINGACTION DD 0 %endif DD PATM_VMFLAGS DD 0 DD PATM_INTERRUPTFLAG DD 0 DD 0ffffffffh SECTION .text ; ; Trampoline code for trap entry (with error code on the stack) ; ; esp + 36 - GS (V86 only) ; esp + 32 - FS (V86 only) ; esp + 28 - DS (V86 only) ; esp + 24 - ES (V86 only) ; esp + 20 - SS (if transfer to inner ring) ; esp + 16 - ESP (if transfer to inner ring) ; esp + 12 - EFLAGS ; esp + 8 - CS ; esp + 4 - EIP ; esp - error code ; BEGINPROC PATMTrapEntryErrorCode PATMTrapErrorCodeEntryStart: mov dword [ss:PATM_INTERRUPTFLAG], 0 pushf %ifdef PATM_LOG_PATCHIRET push eax push ecx push edx lea edx, dword [ss:esp+12+4+4] ;3 dwords + pushed flags + error code -> iret eip mov eax, PATM_ACTION_LOG_GATE_ENTRY lock or dword [ss:PATM_PENDINGACTION], eax mov ecx, PATM_ACTION_MAGIC db 0fh, 0bh ; illegal instr (hardcoded assumption in PATMHandleIllegalInstrTrap) pop edx pop ecx pop eax %endif test dword [esp+16], X86_EFL_VM jnz PATMTrapErrorCodeNoRing1 ; make sure the saved CS selector for ring 1 is made 0 test dword [esp+12], 2 jnz PATMTrapErrorCodeNoRing1 test dword [esp+12], 1 jz PATMTrapErrorCodeNoRing1 and dword [esp+12], dword ~1 ; yasm / nasm dword PATMTrapErrorCodeNoRing1: ; correct EFLAGS on the stack to include the current IOPL push eax mov eax, dword [ss:PATM_VMFLAGS] and eax, X86_EFL_IOPL and dword [esp+20], ~X86_EFL_IOPL ; esp+20 = eflags = esp+8+4(efl)+4(error code)+4(eax) or dword [esp+20], eax pop eax popf mov dword [ss:PATM_INTERRUPTFLAG], 1 DB 0xE9 PATMTrapErrorCodeEntryJump: DD PATM_JUMPDELTA PATMTrapErrorCodeEntryEnd: ENDPROC PATMTrapEntryErrorCode SECTION .data ; Patch record for trap gate entrypoint GLOBALNAME PATMTrapEntryRecordErrorCode RTCCPTR_DEF PATMTrapErrorCodeEntryStart DD PATMTrapErrorCodeEntryJump - PATMTrapErrorCodeEntryStart DD 0 DD 0 DD PATMTrapErrorCodeEntryEnd - PATMTrapErrorCodeEntryStart %ifdef PATM_LOG_PATCHIRET DD 4 %else DD 3 %endif DD PATM_INTERRUPTFLAG DD 0 %ifdef PATM_LOG_PATCHIRET DD PATM_PENDINGACTION DD 0 %endif DD PATM_VMFLAGS DD 0 DD PATM_INTERRUPTFLAG DD 0 DD 0ffffffffh SECTION .text ; ; Trampoline code for interrupt gate entry (without error code on the stack) ; ; esp + 32 - GS (V86 only) ; esp + 28 - FS (V86 only) ; esp + 24 - DS (V86 only) ; esp + 20 - ES (V86 only) ; esp + 16 - SS (if transfer to inner ring) ; esp + 12 - ESP (if transfer to inner ring) ; esp + 8 - EFLAGS ; esp + 4 - CS ; esp - EIP ; BEGINPROC PATMIntEntry PATMIntEntryStart: mov dword [ss:PATM_INTERRUPTFLAG], 0 pushf %ifdef PATM_LOG_PATCHIRET push eax push ecx push edx lea edx, dword [ss:esp+12+4] ;3 dwords + pushed flags -> iret eip mov eax, PATM_ACTION_LOG_GATE_ENTRY lock or dword [ss:PATM_PENDINGACTION], eax mov ecx, PATM_ACTION_MAGIC db 0fh, 0bh ; illegal instr (hardcoded assumption in PATMHandleIllegalInstrTrap) pop edx pop ecx pop eax %endif test dword [esp+12], X86_EFL_VM jnz PATMIntNoRing1 ; make sure the saved CS selector for ring 1 is made 0 test dword [esp+8], 2 jnz PATMIntNoRing1 test dword [esp+8], 1 jz PATMIntNoRing1 and dword [esp+8], dword ~1 ; yasm / nasm dword PATMIntNoRing1: ; correct EFLAGS on the stack to include the current IOPL push eax mov eax, dword [ss:PATM_VMFLAGS] and eax, X86_EFL_IOPL and dword [esp+16], ~X86_EFL_IOPL ; esp+16 = eflags = esp+8+4(efl)+4(eax) or dword [esp+16], eax pop eax popf mov dword [ss:PATM_INTERRUPTFLAG], 1 PATMIntEntryEnd: ENDPROC PATMIntEntry SECTION .data ; Patch record for interrupt gate entrypoint GLOBALNAME PATMIntEntryRecord RTCCPTR_DEF PATMIntEntryStart DD 0 DD 0 DD 0 DD PATMIntEntryEnd - PATMIntEntryStart %ifdef PATM_LOG_PATCHIRET DD 4 %else DD 3 %endif DD PATM_INTERRUPTFLAG DD 0 %ifdef PATM_LOG_PATCHIRET DD PATM_PENDINGACTION DD 0 %endif DD PATM_VMFLAGS DD 0 DD PATM_INTERRUPTFLAG DD 0 DD 0ffffffffh SECTION .text ; ; Trampoline code for interrupt gate entry (*with* error code on the stack) ; ; esp + 36 - GS (V86 only) ; esp + 32 - FS (V86 only) ; esp + 28 - DS (V86 only) ; esp + 24 - ES (V86 only) ; esp + 20 - SS (if transfer to inner ring) ; esp + 16 - ESP (if transfer to inner ring) ; esp + 12 - EFLAGS ; esp + 8 - CS ; esp + 4 - EIP ; esp - error code ; BEGINPROC PATMIntEntryErrorCode PATMIntEntryErrorCodeStart: mov dword [ss:PATM_INTERRUPTFLAG], 0 pushf %ifdef PATM_LOG_PATCHIRET push eax push ecx push edx lea edx, dword [ss:esp+12+4+4] ;3 dwords + pushed flags + error code -> iret eip mov eax, PATM_ACTION_LOG_GATE_ENTRY lock or dword [ss:PATM_PENDINGACTION], eax mov ecx, PATM_ACTION_MAGIC db 0fh, 0bh ; illegal instr (hardcoded assumption in PATMHandleIllegalInstrTrap) pop edx pop ecx pop eax %endif test dword [esp+16], X86_EFL_VM jnz PATMIntNoRing1_ErrorCode ; make sure the saved CS selector for ring 1 is made 0 test dword [esp+12], 2 jnz PATMIntNoRing1_ErrorCode test dword [esp+12], 1 jz PATMIntNoRing1_ErrorCode and dword [esp+12], dword ~1 ; yasm / nasm dword PATMIntNoRing1_ErrorCode: ; correct EFLAGS on the stack to include the current IOPL push eax mov eax, dword [ss:PATM_VMFLAGS] and eax, X86_EFL_IOPL and dword [esp+20], ~X86_EFL_IOPL ; esp+20 = eflags = esp+8+4(efl)+4(eax)+4(error code) or dword [esp+20], eax pop eax popf mov dword [ss:PATM_INTERRUPTFLAG], 1 PATMIntEntryErrorCodeEnd: ENDPROC PATMIntEntryErrorCode SECTION .data ; Patch record for interrupt gate entrypoint GLOBALNAME PATMIntEntryRecordErrorCode RTCCPTR_DEF PATMIntEntryErrorCodeStart DD 0 DD 0 DD 0 DD PATMIntEntryErrorCodeEnd - PATMIntEntryErrorCodeStart %ifdef PATM_LOG_PATCHIRET DD 4 %else DD 3 %endif DD PATM_INTERRUPTFLAG DD 0 %ifdef PATM_LOG_PATCHIRET DD PATM_PENDINGACTION DD 0 %endif DD PATM_VMFLAGS DD 0 DD PATM_INTERRUPTFLAG DD 0 DD 0ffffffffh SECTION .text ; ; 32 bits Popf replacement that faults when IF remains 0 ; BEGINPROC PATMPopf32Replacement PATMPopf32Start: mov dword [ss:PATM_INTERRUPTFLAG], 0 %ifdef PATM_LOG_PATCHINSTR push eax push ecx mov eax, PATM_ACTION_LOG_POPF_IF1 test dword [esp+8], X86_EFL_IF jnz PATMPopf32_Log mov eax, PATM_ACTION_LOG_POPF_IF0 PATMPopf32_Log: lock or dword [ss:PATM_PENDINGACTION], eax mov ecx, PATM_ACTION_MAGIC db 0fh, 0bh ; illegal instr (hardcoded assumption in PATMHandleIllegalInstrTrap) pop ecx pop eax %endif test dword [esp], X86_EFL_IF jnz PATMPopf32_Ok mov dword [ss:PATM_INTERRUPTFLAG], 1 PATM_INT3 PATMPopf32_Ok: ; Note: we don't allow popf instructions to change the current IOPL; we simply ignore such changes (!!!) ; In this particular patch it's rather unlikely the pushf was included, so we have no way to check if the flags on the stack were correctly synced ; PATMPopf32Replacement_NoExit is different, because it's only used in IDT and function patches or dword [ss:PATM_VMFLAGS], X86_EFL_IF ; if interrupts are pending, then we must go back to the host context to handle them! test dword [ss:PATM_VM_FORCEDACTIONS], VMCPU_FF_INTERRUPT_APIC | VMCPU_FF_INTERRUPT_PIC | VMCPU_FF_TIMER | VMCPU_FF_REQUEST jz PATMPopf32_Continue ; Go to our hypervisor trap handler to dispatch the pending irq mov dword [ss:PATM_TEMP_EAX], eax mov dword [ss:PATM_TEMP_ECX], ecx mov dword [ss:PATM_TEMP_EDI], edi mov dword [ss:PATM_TEMP_RESTORE_FLAGS], PATM_RESTORE_EAX | PATM_RESTORE_ECX | PATM_RESTORE_EDI mov eax, PATM_ACTION_DISPATCH_PENDING_IRQ lock or dword [ss:PATM_PENDINGACTION], eax mov ecx, PATM_ACTION_MAGIC mov edi, PATM_NEXTINSTRADDR popfd ; restore flags we pushed above (the or instruction changes the flags as well) db 0fh, 0bh ; illegal instr (hardcoded assumption in PATMHandleIllegalInstrTrap) ; does not return PATMPopf32_Continue: popfd ; restore flags we pushed above mov dword [ss:PATM_INTERRUPTFLAG], 1 DB 0xE9 PATMPopf32Jump: DD PATM_JUMPDELTA PATMPopf32End: ENDPROC PATMPopf32Replacement SECTION .data ; Patch record for 'popfd' GLOBALNAME PATMPopf32Record RTCCPTR_DEF PATMPopf32Start DD PATMPopf32Jump - PATMPopf32Start DD 0 DD 0 DD PATMPopf32End - PATMPopf32Start %ifdef PATM_LOG_PATCHINSTR DD 12 %else DD 11 %endif DD PATM_INTERRUPTFLAG DD 0 %ifdef PATM_LOG_PATCHINSTR DD PATM_PENDINGACTION DD 0 %endif DD PATM_INTERRUPTFLAG DD 0 DD PATM_VMFLAGS DD 0 DD PATM_VM_FORCEDACTIONS DD 0 DD PATM_TEMP_EAX DD 0 DD PATM_TEMP_ECX DD 0 DD PATM_TEMP_EDI DD 0 DD PATM_TEMP_RESTORE_FLAGS DD 0 DD PATM_PENDINGACTION DD 0 DD PATM_NEXTINSTRADDR DD 0 DD PATM_INTERRUPTFLAG DD 0 DD 0ffffffffh SECTION .text ; no need to check the IF flag when popf isn't an exit point of a patch (e.g. function duplication) BEGINPROC PATMPopf32Replacement_NoExit PATMPopf32_NoExitStart: mov dword [ss:PATM_INTERRUPTFLAG], 0 %ifdef PATM_LOG_PATCHINSTR push eax push ecx mov eax, PATM_ACTION_LOG_POPF_IF1 test dword [esp+8], X86_EFL_IF jnz PATMPopf32_NoExitLog mov eax, PATM_ACTION_LOG_POPF_IF0 PATMPopf32_NoExitLog: lock or dword [ss:PATM_PENDINGACTION], eax mov ecx, PATM_ACTION_MAGIC db 0fh, 0bh ; illegal instr (hardcoded assumption in PATMHandleIllegalInstrTrap) pop ecx pop eax %endif test dword [esp], X86_EFL_IF jz PATMPopf32_NoExit_Continue ; if interrupts are pending, then we must go back to the host context to handle them! test dword [ss:PATM_VM_FORCEDACTIONS], VMCPU_FF_INTERRUPT_APIC | VMCPU_FF_INTERRUPT_PIC | VMCPU_FF_TIMER | VMCPU_FF_REQUEST jz PATMPopf32_NoExit_Continue ; Go to our hypervisor trap handler to dispatch the pending irq mov dword [ss:PATM_TEMP_EAX], eax mov dword [ss:PATM_TEMP_ECX], ecx mov dword [ss:PATM_TEMP_EDI], edi mov dword [ss:PATM_TEMP_RESTORE_FLAGS], PATM_RESTORE_EAX | PATM_RESTORE_ECX | PATM_RESTORE_EDI mov eax, PATM_ACTION_DISPATCH_PENDING_IRQ lock or dword [ss:PATM_PENDINGACTION], eax mov ecx, PATM_ACTION_MAGIC mov edi, PATM_NEXTINSTRADDR pop dword [ss:PATM_VMFLAGS] ; restore flags now (the or instruction changes the flags as well) push dword [ss:PATM_VMFLAGS] popfd db 0fh, 0bh ; illegal instr (hardcoded assumption in PATMHandleIllegalInstrTrap) ; does not return PATMPopf32_NoExit_Continue: pop dword [ss:PATM_VMFLAGS] push dword [ss:PATM_VMFLAGS] popfd mov dword [ss:PATM_INTERRUPTFLAG], 1 PATMPopf32_NoExitEnd: ENDPROC PATMPopf32Replacement_NoExit SECTION .data ; Patch record for 'popfd' GLOBALNAME PATMPopf32Record_NoExit RTCCPTR_DEF PATMPopf32_NoExitStart DD 0 DD 0 DD 0 DD PATMPopf32_NoExitEnd - PATMPopf32_NoExitStart %ifdef PATM_LOG_PATCHINSTR DD 14 %else DD 13 %endif DD PATM_INTERRUPTFLAG DD 0 %ifdef PATM_LOG_PATCHINSTR DD PATM_PENDINGACTION DD 0 %endif DD PATM_VM_FORCEDACTIONS DD 0 DD PATM_TEMP_EAX DD 0 DD PATM_TEMP_ECX DD 0 DD PATM_TEMP_EDI DD 0 DD PATM_TEMP_RESTORE_FLAGS DD 0 DD PATM_PENDINGACTION DD 0 DD PATM_NEXTINSTRADDR DD 0 DD PATM_VMFLAGS DD 0 DD PATM_VMFLAGS DD 0 DD PATM_VMFLAGS DD 0 DD PATM_VMFLAGS DD 0 DD PATM_INTERRUPTFLAG DD 0 DD 0ffffffffh SECTION .text ; ; 16 bits Popf replacement that faults when IF remains 0 ; BEGINPROC PATMPopf16Replacement PATMPopf16Start: mov dword [ss:PATM_INTERRUPTFLAG], 0 test word [esp], X86_EFL_IF jnz PATMPopf16_Ok mov dword [ss:PATM_INTERRUPTFLAG], 1 PATM_INT3 PATMPopf16_Ok: ; if interrupts are pending, then we must go back to the host context to handle them! ; @note we destroy the flags here, but that should really not matter (PATM_INT3 case) test dword [ss:PATM_VM_FORCEDACTIONS], VMCPU_FF_INTERRUPT_APIC | VMCPU_FF_INTERRUPT_PIC | VMCPU_FF_TIMER | VMCPU_FF_REQUEST jz PATMPopf16_Continue mov dword [ss:PATM_INTERRUPTFLAG], 1 PATM_INT3 PATMPopf16_Continue: pop word [ss:PATM_VMFLAGS] push word [ss:PATM_VMFLAGS] and dword [ss:PATM_VMFLAGS], PATM_VIRTUAL_FLAGS_MASK or dword [ss:PATM_VMFLAGS], PATM_VIRTUAL_FLAGS_MASK DB 0x66 ; size override popf ;after the and and or operations!! (flags must be preserved) mov dword [ss:PATM_INTERRUPTFLAG], 1 DB 0xE9 PATMPopf16Jump: DD PATM_JUMPDELTA PATMPopf16End: ENDPROC PATMPopf16Replacement SECTION .data ; Patch record for 'popf' GLOBALNAME PATMPopf16Record RTCCPTR_DEF PATMPopf16Start DD PATMPopf16Jump - PATMPopf16Start DD 0 DD 0 DD PATMPopf16End - PATMPopf16Start DD 9 DD PATM_INTERRUPTFLAG DD 0 DD PATM_INTERRUPTFLAG DD 0 DD PATM_VM_FORCEDACTIONS DD 0 DD PATM_INTERRUPTFLAG DD 0 DD PATM_VMFLAGS DD 0 DD PATM_VMFLAGS DD 0 DD PATM_VMFLAGS DD 0 DD PATM_VMFLAGS DD 0 DD PATM_INTERRUPTFLAG DD 0 DD 0ffffffffh SECTION .text ; ; 16 bits Popf replacement that faults when IF remains 0 ; @todo not necessary to fault in that case (see 32 bits version) BEGINPROC PATMPopf16Replacement_NoExit PATMPopf16Start_NoExit: mov dword [ss:PATM_INTERRUPTFLAG], 0 test word [esp], X86_EFL_IF jnz PATMPopf16_Ok_NoExit mov dword [ss:PATM_INTERRUPTFLAG], 1 PATM_INT3 PATMPopf16_Ok_NoExit: ; if interrupts are pending, then we must go back to the host context to handle them! ; @note we destroy the flags here, but that should really not matter (PATM_INT3 case) test dword [ss:PATM_VM_FORCEDACTIONS], VMCPU_FF_INTERRUPT_APIC | VMCPU_FF_INTERRUPT_PIC | VMCPU_FF_TIMER | VMCPU_FF_REQUEST jz PATMPopf16_Continue_NoExit mov dword [ss:PATM_INTERRUPTFLAG], 1 PATM_INT3 PATMPopf16_Continue_NoExit: pop word [ss:PATM_VMFLAGS] push word [ss:PATM_VMFLAGS] and dword [ss:PATM_VMFLAGS], PATM_VIRTUAL_FLAGS_MASK or dword [ss:PATM_VMFLAGS], PATM_VIRTUAL_FLAGS_MASK DB 0x66 ; size override popf ;after the and and or operations!! (flags must be preserved) mov dword [ss:PATM_INTERRUPTFLAG], 1 PATMPopf16End_NoExit: ENDPROC PATMPopf16Replacement_NoExit SECTION .data ; Patch record for 'popf' GLOBALNAME PATMPopf16Record_NoExit RTCCPTR_DEF PATMPopf16Start_NoExit DD 0 DD 0 DD 0 DD PATMPopf16End_NoExit - PATMPopf16Start_NoExit DD 9 DD PATM_INTERRUPTFLAG DD 0 DD PATM_INTERRUPTFLAG DD 0 DD PATM_VM_FORCEDACTIONS DD 0 DD PATM_INTERRUPTFLAG DD 0 DD PATM_VMFLAGS DD 0 DD PATM_VMFLAGS DD 0 DD PATM_VMFLAGS DD 0 DD PATM_VMFLAGS DD 0 DD PATM_INTERRUPTFLAG DD 0 DD 0ffffffffh SECTION .text BEGINPROC PATMPushf32Replacement PATMPushf32Start: mov dword [ss:PATM_INTERRUPTFLAG], 0 pushfd %ifdef PATM_LOG_PATCHINSTR push eax push ecx mov eax, PATM_ACTION_LOG_PUSHF lock or dword [ss:PATM_PENDINGACTION], eax mov ecx, PATM_ACTION_MAGIC db 0fh, 0bh ; illegal instr (hardcoded assumption in PATMHandleIllegalInstrTrap) pop ecx pop eax %endif pushfd push eax mov eax, dword [esp+8] and eax, PATM_FLAGS_MASK or eax, dword [ss:PATM_VMFLAGS] mov dword [esp+8], eax pop eax popfd mov dword [ss:PATM_INTERRUPTFLAG], 1 PATMPushf32End: ENDPROC PATMPushf32Replacement SECTION .data ; Patch record for 'pushfd' GLOBALNAME PATMPushf32Record RTCCPTR_DEF PATMPushf32Start DD 0 DD 0 DD 0 DD PATMPushf32End - PATMPushf32Start %ifdef PATM_LOG_PATCHINSTR DD 4 %else DD 3 %endif DD PATM_INTERRUPTFLAG DD 0 %ifdef PATM_LOG_PATCHINSTR DD PATM_PENDINGACTION DD 0 %endif DD PATM_VMFLAGS DD 0 DD PATM_INTERRUPTFLAG DD 0 DD 0ffffffffh SECTION .text BEGINPROC PATMPushf16Replacement PATMPushf16Start: mov dword [ss:PATM_INTERRUPTFLAG], 0 DB 0x66 ; size override pushf DB 0x66 ; size override pushf push eax xor eax, eax mov ax, word [esp+6] and eax, PATM_FLAGS_MASK or eax, dword [ss:PATM_VMFLAGS] mov word [esp+6], ax pop eax DB 0x66 ; size override popf mov dword [ss:PATM_INTERRUPTFLAG], 1 PATMPushf16End: ENDPROC PATMPushf16Replacement SECTION .data ; Patch record for 'pushf' GLOBALNAME PATMPushf16Record RTCCPTR_DEF PATMPushf16Start DD 0 DD 0 DD 0 DD PATMPushf16End - PATMPushf16Start DD 3 DD PATM_INTERRUPTFLAG DD 0 DD PATM_VMFLAGS DD 0 DD PATM_INTERRUPTFLAG DD 0 DD 0ffffffffh SECTION .text BEGINPROC PATMPushCSReplacement PATMPushCSStart: mov dword [ss:PATM_INTERRUPTFLAG], 0 push cs pushfd test dword [esp+4], 2 jnz pushcs_notring1 ; change dpl from 1 to 0 and dword [esp+4], dword ~1 ; yasm / nasm dword pushcs_notring1: popfd mov dword [ss:PATM_INTERRUPTFLAG], 1 DB 0xE9 PATMPushCSJump: DD PATM_JUMPDELTA PATMPushCSEnd: ENDPROC PATMPushCSReplacement SECTION .data ; Patch record for 'push cs' GLOBALNAME PATMPushCSRecord RTCCPTR_DEF PATMPushCSStart DD PATMPushCSJump - PATMPushCSStart DD 0 DD 0 DD PATMPushCSEnd - PATMPushCSStart DD 2 DD PATM_INTERRUPTFLAG DD 0 DD PATM_INTERRUPTFLAG DD 0 DD 0ffffffffh SECTION .text ;;**************************************************** ;; Abstract: ;; ;; if eflags.NT==0 && iretstack.eflags.VM==0 && iretstack.eflags.IOPL==0 ;; then ;; if return to ring 0 (iretstack.new_cs & 3 == 0) ;; then ;; if iretstack.new_eflags.IF == 1 && iretstack.new_eflags.IOPL == 0 ;; then ;; iretstack.new_cs |= 1 ;; else ;; int 3 ;; endif ;; uVMFlags &= ~X86_EFL_IF ;; iret ;; else ;; int 3 ;;**************************************************** ;; ; Stack: ; ; esp + 32 - GS (V86 only) ; esp + 28 - FS (V86 only) ; esp + 24 - DS (V86 only) ; esp + 20 - ES (V86 only) ; esp + 16 - SS (if transfer to outer ring) ; esp + 12 - ESP (if transfer to outer ring) ; esp + 8 - EFLAGS ; esp + 4 - CS ; esp - EIP ;; BEGINPROC PATMIretReplacement PATMIretStart: mov dword [ss:PATM_INTERRUPTFLAG], 0 pushfd %ifdef PATM_LOG_PATCHIRET push eax push ecx push edx lea edx, dword [ss:esp+12+4] ;3 dwords + pushed flags -> iret eip mov eax, PATM_ACTION_LOG_IRET lock or dword [ss:PATM_PENDINGACTION], eax mov ecx, PATM_ACTION_MAGIC db 0fh, 0bh ; illegal instr (hardcoded assumption in PATMHandleIllegalInstrTrap) pop edx pop ecx pop eax %endif test dword [esp], X86_EFL_NT jnz near iret_fault1 ; we can't do an iret to v86 code, as we run with CPL=1. The iret would attempt a protected mode iret and (most likely) fault. test dword [esp+12], X86_EFL_VM jnz near iret_return_to_v86 ;;!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! ;;@todo: not correct for iret back to ring 2!!!!! ;;!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! test dword [esp+8], 2 jnz iret_notring0 test dword [esp+12], X86_EFL_IF jz near iret_clearIF ; force ring 1 CS RPL or dword [esp+8], 1 iret_notring0: ; if interrupts are pending, then we must go back to the host context to handle them! ; Note: This is very important as pending pic interrupts can be overridden by apic interrupts if we don't check early enough (Fedora 5 boot) ; @@todo fix this properly, so we can dispatch pending interrupts in GC test dword [ss:PATM_VM_FORCEDACTIONS], VMCPU_FF_INTERRUPT_APIC | VMCPU_FF_INTERRUPT_PIC jz iret_continue ; Go to our hypervisor trap handler to dispatch the pending irq mov dword [ss:PATM_TEMP_EAX], eax mov dword [ss:PATM_TEMP_ECX], ecx mov dword [ss:PATM_TEMP_EDI], edi mov dword [ss:PATM_TEMP_RESTORE_FLAGS], PATM_RESTORE_EAX | PATM_RESTORE_ECX | PATM_RESTORE_EDI mov eax, PATM_ACTION_PENDING_IRQ_AFTER_IRET lock or dword [ss:PATM_PENDINGACTION], eax mov ecx, PATM_ACTION_MAGIC mov edi, PATM_CURINSTRADDR popfd db 0fh, 0bh ; illegal instr (hardcoded assumption in PATMHandleIllegalInstrTrap) ; does not return iret_continue : ; This section must *always* be executed (!!) ; Extract the IOPL from the return flags, save them to our virtual flags and ; put them back to zero ; @note we assume iretd doesn't fault!!! push eax mov eax, dword [esp+16] and eax, X86_EFL_IOPL and dword [ss:PATM_VMFLAGS], ~X86_EFL_IOPL or dword [ss:PATM_VMFLAGS], eax pop eax and dword [esp+12], ~X86_EFL_IOPL ; Set IF again; below we make sure this won't cause problems. or dword [ss:PATM_VMFLAGS], X86_EFL_IF ; make sure iret is executed fully (including the iret below; cli ... iret can otherwise be interrupted) mov dword [ss:PATM_INHIBITIRQADDR], PATM_CURINSTRADDR popfd mov dword [ss:PATM_INTERRUPTFLAG], 1 iretd PATM_INT3 iret_fault: popfd mov dword [ss:PATM_INTERRUPTFLAG], 1 PATM_INT3 iret_fault1: nop popfd mov dword [ss:PATM_INTERRUPTFLAG], 1 PATM_INT3 iret_clearIF: push dword [esp+4] ; eip to return to pushfd push eax push PATM_FIXUP DB 0E8h ; call DD PATM_IRET_FUNCTION add esp, 4 ; pushed address of jump table cmp eax, 0 je near iret_fault3 mov dword [esp+12+4], eax ; stored eip in iret frame pop eax popfd add esp, 4 ; pushed eip ; always ring 0 return -> change to ring 1 (CS in iret frame) or dword [esp+8], 1 ; This section must *always* be executed (!!) ; Extract the IOPL from the return flags, save them to our virtual flags and ; put them back to zero push eax mov eax, dword [esp+16] and eax, X86_EFL_IOPL and dword [ss:PATM_VMFLAGS], ~X86_EFL_IOPL or dword [ss:PATM_VMFLAGS], eax pop eax and dword [esp+12], ~X86_EFL_IOPL ; Clear IF and dword [ss:PATM_VMFLAGS], ~X86_EFL_IF popfd ; the patched destination code will set PATM_INTERRUPTFLAG after the return! iretd iret_return_to_v86: test dword [esp+12], X86_EFL_IF jz iret_fault ; Go to our hypervisor trap handler to perform the iret to v86 code mov dword [ss:PATM_TEMP_EAX], eax mov dword [ss:PATM_TEMP_ECX], ecx mov dword [ss:PATM_TEMP_RESTORE_FLAGS], PATM_RESTORE_EAX | PATM_RESTORE_ECX mov eax, PATM_ACTION_DO_V86_IRET lock or dword [ss:PATM_PENDINGACTION], eax mov ecx, PATM_ACTION_MAGIC popfd db 0fh, 0bh ; illegal instr (hardcoded assumption in PATMHandleIllegalInstrTrap) ; does not return iret_fault3: pop eax popfd add esp, 4 ; pushed eip jmp iret_fault align 4 PATMIretTable: DW PATM_MAX_JUMPTABLE_ENTRIES ; nrSlots DW 0 ; ulInsertPos DD 0 ; cAddresses TIMES PATCHJUMPTABLE_SIZE DB 0 ; lookup slots PATMIretEnd: ENDPROC PATMIretReplacement SECTION .data ; Patch record for 'iretd' GLOBALNAME PATMIretRecord RTCCPTR_DEF PATMIretStart DD 0 DD 0 DD 0 DD PATMIretEnd- PATMIretStart %ifdef PATM_LOG_PATCHIRET DD 26 %else DD 25 %endif DD PATM_INTERRUPTFLAG DD 0 %ifdef PATM_LOG_PATCHIRET DD PATM_PENDINGACTION DD 0 %endif DD PATM_VM_FORCEDACTIONS DD 0 DD PATM_TEMP_EAX DD 0 DD PATM_TEMP_ECX DD 0 DD PATM_TEMP_EDI DD 0 DD PATM_TEMP_RESTORE_FLAGS DD 0 DD PATM_PENDINGACTION DD 0 DD PATM_CURINSTRADDR DD 0 DD PATM_VMFLAGS DD 0 DD PATM_VMFLAGS DD 0 DD PATM_VMFLAGS DD 0 DD PATM_INHIBITIRQADDR DD 0 DD PATM_CURINSTRADDR DD 0 DD PATM_INTERRUPTFLAG DD 0 DD PATM_INTERRUPTFLAG DD 0 DD PATM_INTERRUPTFLAG DD 0 DD PATM_FIXUP DD PATMIretTable - PATMIretStart DD PATM_IRET_FUNCTION DD 0 DD PATM_VMFLAGS DD 0 DD PATM_VMFLAGS DD 0 DD PATM_VMFLAGS DD 0 DD PATM_TEMP_EAX DD 0 DD PATM_TEMP_ECX DD 0 DD PATM_TEMP_RESTORE_FLAGS DD 0 DD PATM_PENDINGACTION DD 0 DD 0ffffffffh SECTION .text ; ; global function for implementing 'iret' to code with IF cleared ; ; Caller is responsible for right stack layout ; + 16 original return address ; + 12 eflags ; + 8 eax ; + 4 Jump table address ;( + 0 return address ) ; ; @note assumes PATM_INTERRUPTFLAG is zero ; @note assumes it can trash eax and eflags ; ; @returns eax=0 on failure ; otherwise return address in eax ; ; @note NEVER change this without bumping the SSM version align 32 BEGINPROC PATMIretFunction PATMIretFunction_Start: push ecx push edx push edi ; Event order: ; 1) Check if the return patch address can be found in the lookup table ; 2) Query return patch address from the hypervisor ; 1) Check if the return patch address can be found in the lookup table mov edx, dword [esp+12+16] ; pushed target address xor eax, eax ; default result -> nothing found mov edi, dword [esp+12+4] ; jump table mov ecx, [ss:edi + PATCHJUMPTABLE.cAddresses] cmp ecx, 0 je near PATMIretFunction_AskHypervisor PATMIretFunction_SearchStart: cmp [ss:edi + PATCHJUMPTABLE.Slot_pInstrGC + eax*8], edx ; edx = GC address to search for je near PATMIretFunction_SearchHit inc eax cmp eax, ecx jl near PATMIretFunction_SearchStart PATMIretFunction_AskHypervisor: ; 2) Query return patch address from the hypervisor ; @todo private ugly interface, since we have nothing generic at the moment lock or dword [ss:PATM_PENDINGACTION], PATM_ACTION_LOOKUP_ADDRESS mov eax, PATM_ACTION_LOOKUP_ADDRESS mov ecx, PATM_ACTION_MAGIC mov edi, dword [esp+12+4] ; jump table address mov edx, dword [esp+12+16] ; original return address db 0fh, 0bh ; illegal instr (hardcoded assumption in PATMHandleIllegalInstrTrap) jmp near PATMIretFunction_SearchEnd PATMIretFunction_SearchHit: mov eax, [ss:edi + PATCHJUMPTABLE.Slot_pRelPatchGC + eax*8] ; found a match! ;@note can be zero, so the next check is required!! PATMIretFunction_SearchEnd: cmp eax, 0 jz PATMIretFunction_Failure add eax, PATM_PATCHBASE pop edi pop edx pop ecx ret PATMIretFunction_Failure: ;signal error xor eax, eax pop edi pop edx pop ecx ret PATMIretFunction_End: ENDPROC PATMIretFunction SECTION .data GLOBALNAME PATMIretFunctionRecord RTCCPTR_DEF PATMIretFunction_Start DD 0 DD 0 DD 0 DD PATMIretFunction_End - PATMIretFunction_Start DD 2 DD PATM_PENDINGACTION DD 0 DD PATM_PATCHBASE DD 0 DD 0ffffffffh SECTION .text align 32 ; yasm / nasm diff - remove me! BEGINPROC PATMCpuidReplacement PATMCpuidStart: mov dword [ss:PATM_INTERRUPTFLAG], 0 pushf cmp eax, PATM_CPUID_STD_MAX jb cpuid_std cmp eax, 0x80000000 jb cpuid_def cmp eax, PATM_CPUID_EXT_MAX jb cpuid_ext cmp eax, 0xc0000000 jb cpuid_def cmp eax, PATM_CPUID_CENTAUR_MAX jb cpuid_centaur ; Dirty assumptions in patmCorrectFixup about the pointer fixup order!!!! cpuid_def: mov eax, PATM_CPUID_DEF_PTR jmp cpuid_fetch cpuid_std: mov edx, PATM_CPUID_STD_PTR jmp cpuid_calc cpuid_ext: and eax, 0ffh ; strictly speaking not necessary. mov edx, PATM_CPUID_EXT_PTR jmp cpuid_calc cpuid_centaur: and eax, 0ffh ; strictly speaking not necessary. mov edx, PATM_CPUID_CENTAUR_PTR cpuid_calc: lea eax, [ss:eax * 4] ; 4 entries... lea eax, [ss:eax * 4] ; 4 bytes each add eax, edx cpuid_fetch: mov edx, [ss:eax + 12] ; CPUMCPUID layout assumptions! mov ecx, [ss:eax + 8] mov ebx, [ss:eax + 4] mov eax, [ss:eax] popf mov dword [ss:PATM_INTERRUPTFLAG], 1 PATMCpuidEnd: ENDPROC PATMCpuidReplacement SECTION .data ; Patch record for 'cpuid' GLOBALNAME PATMCpuidRecord RTCCPTR_DEF PATMCpuidStart DD 0 DD 0 DD 0 DD PATMCpuidEnd- PATMCpuidStart DD 9 DD PATM_INTERRUPTFLAG DD 0 DD PATM_CPUID_STD_MAX DD 0 DD PATM_CPUID_EXT_MAX DD 0 DD PATM_CPUID_CENTAUR_MAX DD 0 DD PATM_CPUID_DEF_PTR DD 0 DD PATM_CPUID_STD_PTR DD 0 DD PATM_CPUID_EXT_PTR DD 0 DD PATM_CPUID_CENTAUR_PTR DD 0 DD PATM_INTERRUPTFLAG DD 0 DD 0ffffffffh SECTION .text BEGINPROC PATMJEcxReplacement PATMJEcxStart: mov dword [ss:PATM_INTERRUPTFLAG], 0 pushfd PATMJEcxSizeOverride: DB 0x90 ; nop cmp ecx, dword 0 ; yasm / nasm dword jnz PATMJEcxContinue popfd mov dword [ss:PATM_INTERRUPTFLAG], 1 DB 0xE9 PATMJEcxJump: DD PATM_JUMPDELTA PATMJEcxContinue: popfd mov dword [ss:PATM_INTERRUPTFLAG], 1 PATMJEcxEnd: ENDPROC PATMJEcxReplacement SECTION .data ; Patch record for 'JEcx' GLOBALNAME PATMJEcxRecord RTCCPTR_DEF PATMJEcxStart DD 0 DD PATMJEcxJump - PATMJEcxStart DD PATMJEcxSizeOverride - PATMJEcxStart DD PATMJEcxEnd- PATMJEcxStart DD 3 DD PATM_INTERRUPTFLAG DD 0 DD PATM_INTERRUPTFLAG DD 0 DD PATM_INTERRUPTFLAG DD 0 DD 0ffffffffh SECTION .text align 32; yasm / nasm diffing. remove me! BEGINPROC PATMLoopReplacement PATMLoopStart: mov dword [ss:PATM_INTERRUPTFLAG], 0 pushfd PATMLoopSizeOverride: DB 0x90 ; nop dec ecx jz PATMLoopContinue popfd mov dword [ss:PATM_INTERRUPTFLAG], 1 DB 0xE9 PATMLoopJump: DD PATM_JUMPDELTA PATMLoopContinue: popfd mov dword [ss:PATM_INTERRUPTFLAG], 1 PATMLoopEnd: ENDPROC PATMLoopReplacement SECTION .data ; Patch record for 'Loop' GLOBALNAME PATMLoopRecord RTCCPTR_DEF PATMLoopStart DD 0 DD PATMLoopJump - PATMLoopStart DD PATMLoopSizeOverride - PATMLoopStart DD PATMLoopEnd- PATMLoopStart DD 3 DD PATM_INTERRUPTFLAG DD 0 DD PATM_INTERRUPTFLAG DD 0 DD PATM_INTERRUPTFLAG DD 0 DD 0ffffffffh SECTION .text BEGINPROC PATMLoopZReplacement PATMLoopZStart: ; jump if ZF=1 AND (E)CX != 0 mov dword [ss:PATM_INTERRUPTFLAG], 0 jnz PATMLoopZEnd pushfd PATMLoopZSizeOverride: DB 0x90 ; nop dec ecx jz PATMLoopZContinue popfd mov dword [ss:PATM_INTERRUPTFLAG], 1 DB 0xE9 PATMLoopZJump: DD PATM_JUMPDELTA PATMLoopZContinue: popfd mov dword [ss:PATM_INTERRUPTFLAG], 1 PATMLoopZEnd: ENDPROC PATMLoopZReplacement SECTION .data ; Patch record for 'Loopz' GLOBALNAME PATMLoopZRecord RTCCPTR_DEF PATMLoopZStart DD 0 DD PATMLoopZJump - PATMLoopZStart DD PATMLoopZSizeOverride - PATMLoopZStart DD PATMLoopZEnd- PATMLoopZStart DD 3 DD PATM_INTERRUPTFLAG DD 0 DD PATM_INTERRUPTFLAG DD 0 DD PATM_INTERRUPTFLAG DD 0 DD 0ffffffffh SECTION .text BEGINPROC PATMLoopNZReplacement PATMLoopNZStart: ; jump if ZF=0 AND (E)CX != 0 mov dword [ss:PATM_INTERRUPTFLAG], 0 jz PATMLoopNZEnd pushfd PATMLoopNZSizeOverride: DB 0x90 ; nop dec ecx jz PATMLoopNZContinue popfd mov dword [ss:PATM_INTERRUPTFLAG], 1 DB 0xE9 PATMLoopNZJump: DD PATM_JUMPDELTA PATMLoopNZContinue: popfd mov dword [ss:PATM_INTERRUPTFLAG], 1 PATMLoopNZEnd: ENDPROC PATMLoopNZReplacement SECTION .data ; Patch record for 'LoopNZ' GLOBALNAME PATMLoopNZRecord RTCCPTR_DEF PATMLoopNZStart DD 0 DD PATMLoopNZJump - PATMLoopNZStart DD PATMLoopNZSizeOverride - PATMLoopNZStart DD PATMLoopNZEnd- PATMLoopNZStart DD 3 DD PATM_INTERRUPTFLAG DD 0 DD PATM_INTERRUPTFLAG DD 0 DD PATM_INTERRUPTFLAG DD 0 DD 0ffffffffh SECTION .text align 32 ; Global patch function for indirect calls ; Caller is responsible for clearing PATM_INTERRUPTFLAG and doing: ; + 20 push [pTargetGC] ; + 16 pushfd ; + 12 push [JumpTableAddress] ; + 8 push [PATMRelReturnAddress] ; + 4 push [GuestReturnAddress] ;( + 0 return address ) ; ; @note NEVER change this without bumping the SSM version BEGINPROC PATMLookupAndCall PATMLookupAndCallStart: push eax push edx push edi push ecx mov eax, dword [esp+16+4] ; guest return address mov dword [ss:PATM_CALL_RETURN_ADDR], eax ; temporary storage mov edx, dword [esp+16+20] ; pushed target address xor eax, eax ; default result -> nothing found mov edi, dword [esp+16+12] ; jump table mov ecx, [ss:edi + PATCHJUMPTABLE.cAddresses] cmp ecx, 0 je near PATMLookupAndCall_QueryPATM PATMLookupAndCall_SearchStart: cmp [ss:edi + PATCHJUMPTABLE.Slot_pInstrGC + eax*8], edx ; edx = GC address to search for je near PATMLookupAndCall_SearchHit inc eax cmp eax, ecx jl near PATMLookupAndCall_SearchStart PATMLookupAndCall_QueryPATM: ; nothing found -> let our trap handler try to find it ; @todo private ugly interface, since we have nothing generic at the moment lock or dword [ss:PATM_PENDINGACTION], PATM_ACTION_LOOKUP_ADDRESS mov eax, PATM_ACTION_LOOKUP_ADDRESS mov ecx, PATM_ACTION_MAGIC ; edx = GC address to find ; edi = jump table address db 0fh, 0bh ; illegal instr (hardcoded assumption in PATMHandleIllegalInstrTrap) jmp near PATMLookupAndCall_SearchEnd PATMLookupAndCall_Failure: ; return to caller; it must raise an error, due to patch to guest address translation (remember that there's only one copy of this code block). pop ecx pop edi pop edx pop eax ret PATMLookupAndCall_SearchHit: mov eax, [ss:edi + PATCHJUMPTABLE.Slot_pRelPatchGC + eax*8] ; found a match! ;@note can be zero, so the next check is required!! PATMLookupAndCall_SearchEnd: cmp eax, 0 je near PATMLookupAndCall_Failure mov ecx, eax ; ECX = target address (relative!) add ecx, PATM_PATCHBASE ; Make it absolute mov edx, dword PATM_STACKPTR cmp dword [ss:edx], PATM_STACK_SIZE ja near PATMLookupAndCall_Failure ; should never happen actually!!! cmp dword [ss:edx], 0 je near PATMLookupAndCall_Failure ; no more room ; save the patch return address on our private stack sub dword [ss:edx], 4 ; sizeof(RTGCPTR) mov eax, dword PATM_STACKBASE add eax, dword [ss:edx] ; stack base + stack position mov edi, dword [esp+16+8] ; PATM return address mov dword [ss:eax], edi ; relative address of patch return (instruction following this block) ; save the original return address as well (checked by ret to make sure the guest hasn't messed around with the stack) mov edi, dword PATM_STACKBASE_GUEST add edi, dword [ss:edx] ; stack base (guest) + stack position mov eax, dword [esp+16+4] ; guest return address mov dword [ss:edi], eax mov dword [ss:PATM_CALL_PATCH_TARGET_ADDR], ecx ; temporarily store the target address pop ecx pop edi pop edx pop eax add esp, 24 ; parameters + return address pushed by caller (changes the flags, but that shouldn't matter) %ifdef PATM_LOG_PATCHINSTR push eax push ecx push edx lea edx, [esp + 12 - 4] ; stack address to store return address lock or dword [ss:PATM_PENDINGACTION], PATM_ACTION_LOG_CALL mov eax, PATM_ACTION_LOG_CALL mov ecx, PATM_ACTION_MAGIC db 0fh, 0bh ; illegal instr (hardcoded assumption in PATMHandleIllegalInstrTrap) pop edx pop ecx pop eax %endif push dword [ss:PATM_CALL_RETURN_ADDR] ; push original guest return address ; the called function will set PATM_INTERRUPTFLAG (!!) jmp dword [ss:PATM_CALL_PATCH_TARGET_ADDR] PATMLookupAndCallEnd: ; returning here -> do not add code here or after the jmp!!!!! ENDPROC PATMLookupAndCall SECTION .data ; Patch record for indirect calls and jumps GLOBALNAME PATMLookupAndCallRecord RTCCPTR_DEF PATMLookupAndCallStart DD 0 DD 0 DD 0 DD PATMLookupAndCallEnd - PATMLookupAndCallStart %ifdef PATM_LOG_PATCHINSTR DD 10 %else DD 9 %endif DD PATM_CALL_RETURN_ADDR DD 0 DD PATM_PENDINGACTION DD 0 DD PATM_PATCHBASE DD 0 DD PATM_STACKPTR DD 0 DD PATM_STACKBASE DD 0 DD PATM_STACKBASE_GUEST DD 0 DD PATM_CALL_PATCH_TARGET_ADDR DD 0 %ifdef PATM_LOG_PATCHINSTR DD PATM_PENDINGACTION DD 0 %endif DD PATM_CALL_RETURN_ADDR DD 0 DD PATM_CALL_PATCH_TARGET_ADDR DD 0 DD 0ffffffffh SECTION .text align 32 ; Global patch function for indirect jumps ; Caller is responsible for clearing PATM_INTERRUPTFLAG and doing: ; + 8 push [pTargetGC] ; + 4 push [JumpTableAddress] ;( + 0 return address ) ; And saving eflags in PATM_TEMP_EFLAGS ; ; @note NEVER change this without bumping the SSM version BEGINPROC PATMLookupAndJump PATMLookupAndJumpStart: push eax push edx push edi push ecx mov edx, dword [esp+16+8] ; pushed target address xor eax, eax ; default result -> nothing found mov edi, dword [esp+16+4] ; jump table mov ecx, [ss:edi + PATCHJUMPTABLE.cAddresses] cmp ecx, 0 je near PATMLookupAndJump_QueryPATM PATMLookupAndJump_SearchStart: cmp [ss:edi + PATCHJUMPTABLE.Slot_pInstrGC + eax*8], edx ; edx = GC address to search for je near PATMLookupAndJump_SearchHit inc eax cmp eax, ecx jl near PATMLookupAndJump_SearchStart PATMLookupAndJump_QueryPATM: ; nothing found -> let our trap handler try to find it ; @todo private ugly interface, since we have nothing generic at the moment lock or dword [ss:PATM_PENDINGACTION], PATM_ACTION_LOOKUP_ADDRESS mov eax, PATM_ACTION_LOOKUP_ADDRESS mov ecx, PATM_ACTION_MAGIC ; edx = GC address to find ; edi = jump table address db 0fh, 0bh ; illegal instr (hardcoded assumption in PATMHandleIllegalInstrTrap) jmp near PATMLookupAndJump_SearchEnd PATMLookupAndJump_Failure: ; return to caller; it must raise an error, due to patch to guest address translation (remember that there's only one copy of this code block). pop ecx pop edi pop edx pop eax ret PATMLookupAndJump_SearchHit: mov eax, [ss:edi + PATCHJUMPTABLE.Slot_pRelPatchGC + eax*8] ; found a match! ;@note can be zero, so the next check is required!! PATMLookupAndJump_SearchEnd: cmp eax, 0 je near PATMLookupAndJump_Failure mov ecx, eax ; ECX = target address (relative!) add ecx, PATM_PATCHBASE ; Make it absolute ; save jump patch target mov dword [ss:PATM_TEMP_EAX], ecx pop ecx pop edi pop edx pop eax add esp, 12 ; parameters + return address pushed by caller ; restore flags (just to be sure) push dword [ss:PATM_TEMP_EFLAGS] popfd ; the jump destination will set PATM_INTERRUPTFLAG (!!) jmp dword [ss:PATM_TEMP_EAX] ; call duplicated patch destination address PATMLookupAndJumpEnd: ENDPROC PATMLookupAndJump SECTION .data ; Patch record for indirect calls and jumps GLOBALNAME PATMLookupAndJumpRecord RTCCPTR_DEF PATMLookupAndJumpStart DD 0 DD 0 DD 0 DD PATMLookupAndJumpEnd - PATMLookupAndJumpStart DD 5 DD PATM_PENDINGACTION DD 0 DD PATM_PATCHBASE DD 0 DD PATM_TEMP_EAX DD 0 DD PATM_TEMP_EFLAGS DD 0 DD PATM_TEMP_EAX DD 0 DD 0ffffffffh SECTION .text align 32 ; Patch function for static calls ; @note static calls have only one lookup slot! ; Caller is responsible for clearing PATM_INTERRUPTFLAG and adding: ; push [pTargetGC] ; BEGINPROC PATMCall PATMCallStart: pushfd push PATM_FIXUP ; fixup for jump table below push PATM_PATCHNEXTBLOCK push PATM_RETURNADDR DB 0E8h ; call DD PATM_LOOKUP_AND_CALL_FUNCTION ; we only return in case of a failure add esp, 12 ; pushed address of jump table popfd add esp, 4 ; pushed by caller (changes the flags, but that shouldn't matter (@todo)) mov dword [ss:PATM_INTERRUPTFLAG], 1 PATM_INT3 %ifdef DEBUG ; for disassembly jmp PATMCallEnd %endif align 4 PATMCallTable: DW 1 ; nrSlots DW 0 ; ulInsertPos DD 0 ; cAddresses TIMES PATCHDIRECTJUMPTABLE_SIZE DB 0 ; only one lookup slot PATMCallEnd: ; returning here -> do not add code here or after the jmp!!!!! ENDPROC PATMCall SECTION .data ; Patch record for direct calls GLOBALNAME PATMCallRecord RTCCPTR_DEF PATMCallStart DD 0 DD 0 DD 0 DD PATMCallEnd - PATMCallStart DD 5 DD PATM_FIXUP DD PATMCallTable - PATMCallStart DD PATM_PATCHNEXTBLOCK DD 0 DD PATM_RETURNADDR DD 0 DD PATM_LOOKUP_AND_CALL_FUNCTION DD 0 DD PATM_INTERRUPTFLAG DD 0 DD 0ffffffffh SECTION .text align 32 ; Patch function for indirect calls ; Caller is responsible for clearing PATM_INTERRUPTFLAG and adding: ; push [pTargetGC] ; BEGINPROC PATMCallIndirect PATMCallIndirectStart: pushfd push PATM_FIXUP ; fixup for jump table below push PATM_PATCHNEXTBLOCK push PATM_RETURNADDR DB 0E8h ; call DD PATM_LOOKUP_AND_CALL_FUNCTION ; we only return in case of a failure add esp, 12 ; pushed address of jump table popfd add esp, 4 ; pushed by caller (changes the flags, but that shouldn't matter (@todo)) mov dword [ss:PATM_INTERRUPTFLAG], 1 PATM_INT3 %ifdef DEBUG ; for disassembly jmp PATMCallIndirectEnd %endif align 4 PATMCallIndirectTable: DW PATM_MAX_JUMPTABLE_ENTRIES ; nrSlots DW 0 ; ulInsertPos DD 0 ; cAddresses TIMES PATCHJUMPTABLE_SIZE DB 0 ; lookup slots PATMCallIndirectEnd: ; returning here -> do not add code here or after the jmp!!!!! ENDPROC PATMCallIndirect SECTION .data ; Patch record for indirect calls GLOBALNAME PATMCallIndirectRecord RTCCPTR_DEF PATMCallIndirectStart DD 0 DD 0 DD 0 DD PATMCallIndirectEnd - PATMCallIndirectStart DD 5 DD PATM_FIXUP DD PATMCallIndirectTable - PATMCallIndirectStart DD PATM_PATCHNEXTBLOCK DD 0 DD PATM_RETURNADDR DD 0 DD PATM_LOOKUP_AND_CALL_FUNCTION DD 0 DD PATM_INTERRUPTFLAG DD 0 DD 0ffffffffh SECTION .text align 32 ; Patch function for indirect jumps ; Caller is responsible for clearing PATM_INTERRUPTFLAG and adding: ; push [pTargetGC] ; BEGINPROC PATMJumpIndirect PATMJumpIndirectStart: ; save flags (just to be sure) pushfd pop dword [ss:PATM_TEMP_EFLAGS] push PATM_FIXUP ; fixup for jump table below DB 0E8h ; call DD PATM_LOOKUP_AND_JUMP_FUNCTION ; we only return in case of a failure add esp, 8 ; pushed address of jump table + pushed target address ; restore flags (just to be sure) push dword [ss:PATM_TEMP_EFLAGS] popfd mov dword [ss:PATM_INTERRUPTFLAG], 1 PATM_INT3 %ifdef DEBUG ; for disassembly jmp PATMJumpIndirectEnd %endif align 4 PATMJumpIndirectTable: DW PATM_MAX_JUMPTABLE_ENTRIES ; nrSlots DW 0 ; ulInsertPos DD 0 ; cAddresses TIMES PATCHJUMPTABLE_SIZE DB 0 ; lookup slots PATMJumpIndirectEnd: ; returning here -> do not add code here or after the jmp!!!!! ENDPROC PATMJumpIndirect SECTION .data ; Patch record for indirect jumps GLOBALNAME PATMJumpIndirectRecord RTCCPTR_DEF PATMJumpIndirectStart DD 0 DD 0 DD 0 DD PATMJumpIndirectEnd - PATMJumpIndirectStart DD 5 DD PATM_TEMP_EFLAGS DD 0 DD PATM_FIXUP DD PATMJumpIndirectTable - PATMJumpIndirectStart DD PATM_LOOKUP_AND_JUMP_FUNCTION DD 0 DD PATM_TEMP_EFLAGS DD 0 DD PATM_INTERRUPTFLAG DD 0 DD 0ffffffffh SECTION .text ; ; return from duplicated function ; align 32 BEGINPROC PATMRet PATMRet_Start: ; probe stack here as we can't recover from page faults later on not dword [esp-32] not dword [esp-32] mov dword [ss:PATM_INTERRUPTFLAG], 0 pushfd push eax push PATM_FIXUP DB 0E8h ; call DD PATM_RETURN_FUNCTION add esp, 4 ; pushed address of jump table cmp eax, 0 jne near PATMRet_Success pop eax popfd mov dword [ss:PATM_INTERRUPTFLAG], 1 PATM_INT3 %ifdef DEBUG ; for disassembly jmp PATMRet_Success %endif align 4 PATMRetTable: DW PATM_MAX_JUMPTABLE_ENTRIES ; nrSlots DW 0 ; ulInsertPos DD 0 ; cAddresses TIMES PATCHJUMPTABLE_SIZE DB 0 ; lookup slots PATMRet_Success: mov dword [esp+8], eax ; overwrite the saved return address pop eax popf ; caller will duplicate the ret or ret n instruction ; the patched call will set PATM_INTERRUPTFLAG after the return! PATMRet_End: ENDPROC PATMRet SECTION .data GLOBALNAME PATMRetRecord RTCCPTR_DEF PATMRet_Start DD 0 DD 0 DD 0 DD PATMRet_End - PATMRet_Start DD 4 DD PATM_INTERRUPTFLAG DD 0 DD PATM_FIXUP DD PATMRetTable - PATMRet_Start DD PATM_RETURN_FUNCTION DD 0 DD PATM_INTERRUPTFLAG DD 0 DD 0ffffffffh SECTION .text ; ; global function for implementing 'retn' ; ; Caller is responsible for right stack layout ; + 16 original return address ; + 12 eflags ; + 8 eax ; + 4 Jump table address ;( + 0 return address ) ; ; @note assumes PATM_INTERRUPTFLAG is zero ; @note assumes it can trash eax and eflags ; ; @returns eax=0 on failure ; otherwise return address in eax ; ; @note NEVER change this without bumping the SSM version align 32 BEGINPROC PATMRetFunction PATMRetFunction_Start: push ecx push edx push edi ; Event order: ; (@todo figure out which path is taken most often (1 or 2)) ; 1) Check if the return patch address was pushed onto the PATM stack ; 2) Check if the return patch address can be found in the lookup table ; 3) Query return patch address from the hypervisor ; 1) Check if the return patch address was pushed on the PATM stack cmp dword [ss:PATM_STACKPTR], PATM_STACK_SIZE jae near PATMRetFunction_FindReturnAddress mov edx, dword PATM_STACKPTR ; check if the return address is what we expect it to be mov eax, dword PATM_STACKBASE_GUEST add eax, dword [ss:edx] ; stack base + stack position mov eax, dword [ss:eax] ; original return address cmp eax, dword [esp+12+16] ; pushed return address ; the return address was changed -> let our trap handler try to find it ; (can happen when the guest messes with the stack (seen it) or when we didn't call this function ourselves) jne near PATMRetFunction_FindReturnAddress ; found it, convert relative to absolute patch address and return the result to the caller mov eax, dword PATM_STACKBASE add eax, dword [ss:edx] ; stack base + stack position mov eax, dword [ss:eax] ; relative patm return address add eax, PATM_PATCHBASE %ifdef PATM_LOG_PATCHINSTR push eax push ebx push ecx push edx mov edx, eax ; return address lea ebx, [esp+16+12+16] ; stack address containing the return address lock or dword [ss:PATM_PENDINGACTION], PATM_ACTION_LOG_RET mov eax, PATM_ACTION_LOG_RET mov ecx, PATM_ACTION_MAGIC db 0fh, 0bh ; illegal instr (hardcoded assumption in PATMHandleIllegalInstrTrap) pop edx pop ecx pop ebx pop eax %endif add dword [ss:edx], 4 ; pop return address from the PATM stack (sizeof(RTGCPTR); @note hardcoded assumption!) pop edi pop edx pop ecx ret PATMRetFunction_FindReturnAddress: ; 2) Check if the return patch address can be found in the lookup table mov edx, dword [esp+12+16] ; pushed target address xor eax, eax ; default result -> nothing found mov edi, dword [esp+12+4] ; jump table mov ecx, [ss:edi + PATCHJUMPTABLE.cAddresses] cmp ecx, 0 je near PATMRetFunction_AskHypervisor PATMRetFunction_SearchStart: cmp [ss:edi + PATCHJUMPTABLE.Slot_pInstrGC + eax*8], edx ; edx = GC address to search for je near PATMRetFunction_SearchHit inc eax cmp eax, ecx jl near PATMRetFunction_SearchStart PATMRetFunction_AskHypervisor: ; 3) Query return patch address from the hypervisor ; @todo private ugly interface, since we have nothing generic at the moment lock or dword [ss:PATM_PENDINGACTION], PATM_ACTION_LOOKUP_ADDRESS mov eax, PATM_ACTION_LOOKUP_ADDRESS mov ecx, PATM_ACTION_MAGIC mov edi, dword [esp+12+4] ; jump table address mov edx, dword [esp+12+16] ; original return address db 0fh, 0bh ; illegal instr (hardcoded assumption in PATMHandleIllegalInstrTrap) jmp near PATMRetFunction_SearchEnd PATMRetFunction_SearchHit: mov eax, [ss:edi + PATCHJUMPTABLE.Slot_pRelPatchGC + eax*8] ; found a match! ;@note can be zero, so the next check is required!! PATMRetFunction_SearchEnd: cmp eax, 0 jz PATMRetFunction_Failure add eax, PATM_PATCHBASE %ifdef PATM_LOG_PATCHINSTR push eax push ebx push ecx push edx mov edx, eax ; return address lea ebx, [esp+16+12+16] ; stack address containing the return address lock or dword [ss:PATM_PENDINGACTION], PATM_ACTION_LOG_RET mov eax, PATM_ACTION_LOG_RET mov ecx, PATM_ACTION_MAGIC db 0fh, 0bh ; illegal instr (hardcoded assumption in PATMHandleIllegalInstrTrap) pop edx pop ecx pop ebx pop eax %endif pop edi pop edx pop ecx ret PATMRetFunction_Failure: ;signal error xor eax, eax pop edi pop edx pop ecx ret PATMRetFunction_End: ENDPROC PATMRetFunction SECTION .data GLOBALNAME PATMRetFunctionRecord RTCCPTR_DEF PATMRetFunction_Start DD 0 DD 0 DD 0 DD PATMRetFunction_End - PATMRetFunction_Start %ifdef PATM_LOG_PATCHINSTR DD 9 %else DD 7 %endif DD PATM_STACKPTR DD 0 DD PATM_STACKPTR DD 0 DD PATM_STACKBASE_GUEST DD 0 DD PATM_STACKBASE DD 0 DD PATM_PATCHBASE DD 0 %ifdef PATM_LOG_PATCHINSTR DD PATM_PENDINGACTION DD 0 %endif DD PATM_PENDINGACTION DD 0 DD PATM_PATCHBASE DD 0 %ifdef PATM_LOG_PATCHINSTR DD PATM_PENDINGACTION DD 0 %endif DD 0ffffffffh SECTION .text ; ; Jump to original instruction if IF=1 ; BEGINPROC PATMCheckIF PATMCheckIF_Start: mov dword [ss:PATM_INTERRUPTFLAG], 0 pushf test dword [ss:PATM_VMFLAGS], X86_EFL_IF jnz PATMCheckIF_Safe nop ; IF=0 -> unsafe, so we must call the duplicated function (which we don't do here) popf mov dword [ss:PATM_INTERRUPTFLAG], 1 jmp PATMCheckIF_End PATMCheckIF_Safe: ; invalidate the PATM stack as we'll jump back to guest code mov dword [ss:PATM_STACKPTR], PATM_STACK_SIZE %ifdef PATM_LOG_PATCHINSTR push eax push ecx lock or dword [ss:PATM_PENDINGACTION], PATM_ACTION_LOG_IF1 mov eax, PATM_ACTION_LOG_IF1 mov ecx, PATM_ACTION_MAGIC db 0fh, 0bh ; illegal instr (hardcoded assumption in PATMHandleIllegalInstrTrap) pop ecx pop eax %endif popf mov dword [ss:PATM_INTERRUPTFLAG], 1 ; IF=1 -> we can safely jump back to the original instruction DB 0xE9 PATMCheckIF_Jump: DD PATM_JUMPDELTA PATMCheckIF_End: ENDPROC PATMCheckIF SECTION .data ; Patch record for call instructions GLOBALNAME PATMCheckIFRecord RTCCPTR_DEF PATMCheckIF_Start DD PATMCheckIF_Jump - PATMCheckIF_Start DD 0 DD 0 DD PATMCheckIF_End - PATMCheckIF_Start %ifdef PATM_LOG_PATCHINSTR DD 6 %else DD 5 %endif DD PATM_INTERRUPTFLAG DD 0 DD PATM_VMFLAGS DD 0 DD PATM_INTERRUPTFLAG DD 0 DD PATM_STACKPTR DD 0 %ifdef PATM_LOG_PATCHINSTR DD PATM_PENDINGACTION DD 0 %endif DD PATM_INTERRUPTFLAG DD 0 DD 0ffffffffh SECTION .text ; ; Jump back to guest if IF=1, else fault ; BEGINPROC PATMJumpToGuest_IF1 PATMJumpToGuest_IF1_Start: mov dword [ss:PATM_INTERRUPTFLAG], 0 pushf test dword [ss:PATM_VMFLAGS], X86_EFL_IF jnz PATMJumpToGuest_IF1_Safe nop ; IF=0 -> unsafe, so fault popf mov dword [ss:PATM_INTERRUPTFLAG], 1 PATM_INT3 PATMJumpToGuest_IF1_Safe: ; IF=1 -> we can safely jump back to the original instruction popf mov dword [ss:PATM_INTERRUPTFLAG], 1 DB 0xE9 PATMJumpToGuest_IF1_Jump: DD PATM_JUMPDELTA PATMJumpToGuest_IF1_End: ENDPROC PATMJumpToGuest_IF1 SECTION .data ; Patch record for call instructions GLOBALNAME PATMJumpToGuest_IF1Record RTCCPTR_DEF PATMJumpToGuest_IF1_Start DD PATMJumpToGuest_IF1_Jump - PATMJumpToGuest_IF1_Start DD 0 DD 0 DD PATMJumpToGuest_IF1_End - PATMJumpToGuest_IF1_Start DD 4 DD PATM_INTERRUPTFLAG DD 0 DD PATM_VMFLAGS DD 0 DD PATM_INTERRUPTFLAG DD 0 DD PATM_INTERRUPTFLAG DD 0 DD 0ffffffffh SECTION .text ; check and correct RPL of pushed ss BEGINPROC PATMMovFromSS PATMMovFromSS_Start: push eax pushfd mov ax, ss and ax, 3 cmp ax, 1 jne near PATMMovFromSS_Continue and dword [esp+8], ~3 ; clear RPL 1 PATMMovFromSS_Continue: popfd pop eax PATMMovFromSS_Start_End: ENDPROC PATMMovFromSS SECTION .data GLOBALNAME PATMMovFromSSRecord RTCCPTR_DEF PATMMovFromSS_Start DD 0 DD 0 DD 0 DD PATMMovFromSS_Start_End - PATMMovFromSS_Start DD 0 DD 0ffffffffh SECTION .rodata ; For assertion during init (to make absolutely sure the flags are in sync in vm.mac & vm.h) GLOBALNAME PATMInterruptFlag DD VMCPU_FF_INTERRUPT_APIC | VMCPU_FF_INTERRUPT_PIC | VMCPU_FF_TIMER | VMCPU_FF_REQUEST