/* $Id: PATMGC.cpp 5999 2007-12-07 15:05:06Z vboxsync $ */ /** @file * PATM - Dynamic Guest OS Patching Manager - Guest Context */ /* * Copyright (C) 2006-2007 innotek GmbH * * 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. */ /******************************************************************************* * Header Files * *******************************************************************************/ #define LOG_GROUP LOG_GROUP_PATM #include #include #include #include #include #include #include #include #include #include "PATMInternal.h" #include "PATMA.h" #include #include #include #include #include #include #include #include #include #include #include #include #include /** * #PF Virtual Handler callback for Guest access a page monitored by PATM * * @returns VBox status code (appropritate for trap handling and GC return). * @param pVM VM Handle. * @param uErrorCode CPU Error code. * @param pRegFrame Trap register frame. * @param pvFault The fault address (cr2). * @param pvRange The base address of the handled virtual range. * @param offRange The offset of the access into this range. * (If it's a EIP range this's the EIP, if not it's pvFault.) */ PATMGCDECL(int) PATMGCMonitorPage(PVM pVM, RTGCUINT uErrorCode, PCPUMCTXCORE pRegFrame, void *pvFault, void *pvRange, uintptr_t offRange) { pVM->patm.s.pvFaultMonitor = pvFault; return VINF_PATM_CHECK_PATCH_PAGE; } /** * Checks if the write is located on a page with was patched before. * (if so, then we are not allowed to turn on r/w) * * @returns VBox status * @param pVM The VM to operate on. * @param pRegFrame CPU context * @param GCPtr GC pointer to write address * @param cbWrite Nr of bytes to write * */ PATMGCDECL(int) PATMGCHandleWriteToPatchPage(PVM pVM, PCPUMCTXCORE pRegFrame, RTGCPTR GCPtr, uint32_t cbWrite) { RTGCUINTPTR pWritePageStart, pWritePageEnd; PPATMPATCHPAGE pPatchPage; /* Quick boundary check */ if ( PAGE_ADDRESS(GCPtr) < PAGE_ADDRESS(pVM->patm.s.pPatchedInstrGCLowest) || PAGE_ADDRESS(GCPtr) > PAGE_ADDRESS(pVM->patm.s.pPatchedInstrGCHighest) ) return VERR_PATCH_NOT_FOUND; STAM_PROFILE_ADV_START(&pVM->patm.s.StatPatchWriteDetect, a); pWritePageStart = (RTGCUINTPTR)GCPtr & PAGE_BASE_GC_MASK; pWritePageEnd = ((RTGCUINTPTR)GCPtr + cbWrite - 1) & PAGE_BASE_GC_MASK; pPatchPage = (PPATMPATCHPAGE)RTAvloGCPtrGet(CTXSUFF(&pVM->patm.s.PatchLookupTree)->PatchTreeByPage, (RTGCPTR)pWritePageStart); if ( !pPatchPage && pWritePageStart != pWritePageEnd ) { pPatchPage = (PPATMPATCHPAGE)RTAvloGCPtrGet(CTXSUFF(&pVM->patm.s.PatchLookupTree)->PatchTreeByPage, (RTGCPTR)pWritePageEnd); } #ifdef LOG_ENABLED if (pPatchPage) Log(("PATMIsWriteToPatchPage: Found page %VGv for write to %VGv %d bytes (page low:high %VGv:%VGv\n", pPatchPage->Core.Key, GCPtr, cbWrite, pPatchPage->pLowestAddrGC, pPatchPage->pHighestAddrGC)); #endif if (pPatchPage) { if ( pPatchPage->pLowestAddrGC > (RTGCPTR)((RTGCUINTPTR)GCPtr + cbWrite - 1) || pPatchPage->pHighestAddrGC < GCPtr) { /* This part of the page was not patched; try to emulate the instruction. */ uint32_t cb; LogFlow(("PATMHandleWriteToPatchPage: Interpret %VGv accessing %VGv\n", pRegFrame->eip, GCPtr)); int rc = EMInterpretInstruction(pVM, pRegFrame, GCPtr, &cb); if (rc == VINF_SUCCESS) { STAM_COUNTER_INC(&pVM->patm.s.StatPatchWriteInterpreted); STAM_PROFILE_ADV_STOP(&pVM->patm.s.StatPatchWriteDetect, a); return VINF_SUCCESS; } STAM_COUNTER_INC(&pVM->patm.s.StatPatchWriteInterpretedFailed); } R3PTRTYPE(PPATCHINFO) *paPatch = (R3PTRTYPE(PPATCHINFO) *)MMHyperHC2GC(pVM, pPatchPage->aPatch); /* Increase the invalid write counter for each patch that's registered for that page. */ for (uint32_t i=0;icCount;i++) { PPATCHINFO pPatch = (PPATCHINFO)MMHyperHC2GC(pVM, paPatch[i]); pPatch->cInvalidWrites++; } STAM_PROFILE_ADV_STOP(&pVM->patm.s.StatPatchWriteDetect, a); return VINF_EM_RAW_EMULATE_INSTR; } STAM_PROFILE_ADV_STOP(&pVM->patm.s.StatPatchWriteDetect, a); return VERR_PATCH_NOT_FOUND; } /** * Checks if the illegal instruction was caused by a patched instruction * * @returns VBox status * * @param pVM The VM handle. * @param pCtxCore The relevant core context. */ PATMDECL(int) PATMGCHandleIllegalInstrTrap(PVM pVM, PCPUMCTXCORE pRegFrame) { PPATMPATCHREC pRec; int rc; /* Very important check -> otherwise we have a security leak. */ AssertReturn(!pRegFrame->eflags.Bits.u1VM && (pRegFrame->ss & X86_SEL_RPL) == 1, VERR_ACCESS_DENIED); Assert(PATMIsPatchGCAddr(pVM, (RTGCPTR)pRegFrame->eip)); /* OP_ILLUD2 in PATM generated code? */ if (CTXSUFF(pVM->patm.s.pGCState)->uPendingAction) { LogFlow(("PATMGC: Pending action %x at %VGv\n", CTXSUFF(pVM->patm.s.pGCState)->uPendingAction, pRegFrame->eip)); /* Private PATM interface (@todo hack due to lack of anything generic). */ /* Parameters: * eax = Pending action (currently PATM_ACTION_LOOKUP_ADDRESS) * ecx = PATM_ACTION_MAGIC */ if ( (pRegFrame->eax & CTXSUFF(pVM->patm.s.pGCState)->uPendingAction) && pRegFrame->ecx == PATM_ACTION_MAGIC ) { CTXSUFF(pVM->patm.s.pGCState)->uPendingAction = 0; switch (pRegFrame->eax) { case PATM_ACTION_LOOKUP_ADDRESS: { /* Parameters: * edx = GC address to find * edi = PATCHJUMPTABLE ptr */ AssertMsg(!pRegFrame->edi || PATMIsPatchGCAddr(pVM, (RTGCPTR)pRegFrame->edi), ("edx = %VGv\n", pRegFrame->edi)); Log(("PATMGC: lookup %VGv jump table=%VGv\n", pRegFrame->edx, pRegFrame->edi)); pRec = PATMQueryFunctionPatch(pVM, (RTGCPTR)(pRegFrame->edx)); if (pRec) { if (pRec->patch.uState == PATCH_ENABLED) { RTGCUINTPTR pRelAddr = pRec->patch.pPatchBlockOffset; /* make it relative */ rc = PATMAddBranchToLookupCache(pVM, (RTGCPTR)pRegFrame->edi, (RTGCPTR)pRegFrame->edx, pRelAddr); if (rc == VINF_SUCCESS) { pRegFrame->eip += PATM_ILLEGAL_INSTR_SIZE; pRegFrame->eax = pRelAddr; STAM_COUNTER_INC(&pVM->patm.s.StatFunctionFound); return VINF_SUCCESS; } AssertFailed(); } else { pRegFrame->eip += PATM_ILLEGAL_INSTR_SIZE; pRegFrame->eax = 0; /* make it fault */ STAM_COUNTER_INC(&pVM->patm.s.StatFunctionNotFound); return VINF_SUCCESS; } } else { #if 0 if (pRegFrame->edx == 0x806eca98) { pRegFrame->eip += PATM_ILLEGAL_INSTR_SIZE; pRegFrame->eax = 0; /* make it fault */ STAM_COUNTER_INC(&pVM->patm.s.StatFunctionNotFound); return VINF_SUCCESS; } #endif STAM_COUNTER_INC(&pVM->patm.s.StatFunctionNotFound); return VINF_PATM_DUPLICATE_FUNCTION; } } case PATM_ACTION_DISPATCH_PENDING_IRQ: /* Parameters: * edi = GC address to jump to */ Log(("PATMGC: Dispatch pending interrupt; eip=%VGv->%VGv\n", pRegFrame->eip, pRegFrame->edi)); /* Change EIP to the guest address the patch would normally jump to after setting IF. */ pRegFrame->eip = pRegFrame->edi; Assert(pVM->patm.s.CTXSUFF(pGCState)->Restore.uFlags == (PATM_RESTORE_EAX|PATM_RESTORE_ECX|PATM_RESTORE_EDI)); Assert(pVM->patm.s.CTXSUFF(pGCState)->fPIF == 0); pRegFrame->eax = pVM->patm.s.CTXSUFF(pGCState)->Restore.uEAX; pRegFrame->ecx = pVM->patm.s.CTXSUFF(pGCState)->Restore.uECX; pRegFrame->edi = pVM->patm.s.CTXSUFF(pGCState)->Restore.uEDI; pVM->patm.s.CTXSUFF(pGCState)->Restore.uFlags = 0; /* We are no longer executing PATM code; set PIF again. */ pVM->patm.s.CTXSUFF(pGCState)->fPIF = 1; STAM_COUNTER_INC(&pVM->patm.s.StatCheckPendingIRQ); /* The caller will call trpmGCExitTrap, which will dispatch pending interrupts for us. */ return VINF_SUCCESS; case PATM_ACTION_PENDING_IRQ_AFTER_IRET: /* Parameters: * edi = GC address to jump to */ Log(("PATMGC: Dispatch pending interrupt (iret); eip=%VGv->%VGv\n", pRegFrame->eip, pRegFrame->edi)); Assert(pVM->patm.s.CTXSUFF(pGCState)->Restore.uFlags == (PATM_RESTORE_EAX|PATM_RESTORE_ECX|PATM_RESTORE_EDI)); Assert(pVM->patm.s.CTXSUFF(pGCState)->fPIF == 0); /* Change EIP to the guest address of the iret. */ pRegFrame->eip = pRegFrame->edi; pRegFrame->eax = pVM->patm.s.CTXSUFF(pGCState)->Restore.uEAX; pRegFrame->ecx = pVM->patm.s.CTXSUFF(pGCState)->Restore.uECX; pRegFrame->edi = pVM->patm.s.CTXSUFF(pGCState)->Restore.uEDI; pVM->patm.s.CTXSUFF(pGCState)->Restore.uFlags = 0; /* We are no longer executing PATM code; set PIF again. */ pVM->patm.s.CTXSUFF(pGCState)->fPIF = 1; return VINF_PATM_PENDING_IRQ_AFTER_IRET; case PATM_ACTION_DO_V86_IRET: { Log(("PATMGC: Do iret to V86 code; eip=%VGv\n", pRegFrame->eip)); Assert(pVM->patm.s.CTXSUFF(pGCState)->Restore.uFlags == (PATM_RESTORE_EAX|PATM_RESTORE_ECX)); Assert(pVM->patm.s.CTXSUFF(pGCState)->fPIF == 0); pRegFrame->eax = pVM->patm.s.CTXSUFF(pGCState)->Restore.uEAX; pRegFrame->ecx = pVM->patm.s.CTXSUFF(pGCState)->Restore.uECX; pVM->patm.s.CTXSUFF(pGCState)->Restore.uFlags = 0; rc = EMInterpretIret(pVM, pRegFrame); if (VBOX_SUCCESS(rc)) { STAM_COUNTER_INC(&pVM->patm.s.StatEmulIret); /* We are no longer executing PATM code; set PIF again. */ pVM->patm.s.CTXSUFF(pGCState)->fPIF = 1; CPUMGCCallV86Code(pRegFrame); /* does not return */ } else STAM_COUNTER_INC(&pVM->patm.s.StatEmulIretFailed); return rc; } #ifdef DEBUG case PATM_ACTION_LOG_CLI: Log(("PATMGC: CLI at %VGv (current IF=%d iopl=%d)\n", pRegFrame->eip, !!(pVM->patm.s.CTXSUFF(pGCState)->uVMFlags & X86_EFL_IF), X86_EFL_GET_IOPL(pVM->patm.s.CTXSUFF(pGCState)->uVMFlags) )); pRegFrame->eip += PATM_ILLEGAL_INSTR_SIZE; return VINF_SUCCESS; case PATM_ACTION_LOG_STI: Log(("PATMGC: STI at %VGv (current IF=%d iopl=%d)\n", pRegFrame->eip, !!(pVM->patm.s.CTXSUFF(pGCState)->uVMFlags & X86_EFL_IF), X86_EFL_GET_IOPL(pVM->patm.s.CTXSUFF(pGCState)->uVMFlags) )); pRegFrame->eip += PATM_ILLEGAL_INSTR_SIZE; return VINF_SUCCESS; case PATM_ACTION_LOG_POPF_IF1: Log(("PATMGC: POPF setting IF at %VGv (current IF=%d iopl=%d)\n", pRegFrame->eip, !!(pVM->patm.s.CTXSUFF(pGCState)->uVMFlags & X86_EFL_IF), X86_EFL_GET_IOPL(pVM->patm.s.CTXSUFF(pGCState)->uVMFlags))); pRegFrame->eip += PATM_ILLEGAL_INSTR_SIZE; return VINF_SUCCESS; case PATM_ACTION_LOG_POPF_IF0: Log(("PATMGC: POPF at %VGv (current IF=%d iopl=%d)\n", pRegFrame->eip, !!(pVM->patm.s.CTXSUFF(pGCState)->uVMFlags & X86_EFL_IF), X86_EFL_GET_IOPL(pVM->patm.s.CTXSUFF(pGCState)->uVMFlags))); pRegFrame->eip += PATM_ILLEGAL_INSTR_SIZE; return VINF_SUCCESS; case PATM_ACTION_LOG_PUSHF: Log(("PATMGC: PUSHF at %VGv (current IF=%d iopl=%d)\n", pRegFrame->eip, !!(pVM->patm.s.CTXSUFF(pGCState)->uVMFlags & X86_EFL_IF), X86_EFL_GET_IOPL(pVM->patm.s.CTXSUFF(pGCState)->uVMFlags) )); pRegFrame->eip += PATM_ILLEGAL_INSTR_SIZE; return VINF_SUCCESS; case PATM_ACTION_LOG_IF1: Log(("PATMGC: IF=1 escape from %VGv\n", pRegFrame->eip)); pRegFrame->eip += PATM_ILLEGAL_INSTR_SIZE; return VINF_SUCCESS; case PATM_ACTION_LOG_IRET: { char *pIretFrame = (char *)pRegFrame->edx; uint32_t eip, selCS, uEFlags; rc = MMGCRamRead(pVM, &eip, pIretFrame, 4); rc |= MMGCRamRead(pVM, &selCS, pIretFrame + 4, 4); rc |= MMGCRamRead(pVM, &uEFlags, pIretFrame + 8, 4); if (rc == VINF_SUCCESS) { if ( (uEFlags & X86_EFL_VM) || (selCS & X86_SEL_RPL) == 3) { uint32_t selSS, esp; rc |= MMGCRamRead(pVM, &esp, pIretFrame + 12, 4); rc |= MMGCRamRead(pVM, &selSS, pIretFrame + 16, 4); if (uEFlags & X86_EFL_VM) { uint32_t selDS, selES, selFS, selGS; rc = MMGCRamRead(pVM, &selES, pIretFrame + 20, 4); rc |= MMGCRamRead(pVM, &selDS, pIretFrame + 24, 4); rc |= MMGCRamRead(pVM, &selFS, pIretFrame + 28, 4); rc |= MMGCRamRead(pVM, &selGS, pIretFrame + 32, 4); if (rc == VINF_SUCCESS) { Log(("PATMGC: IRET->VM stack frame: return address %04X:%VGv eflags=%08x ss:esp=%04X:%VGv\n", selCS, eip, uEFlags, selSS, esp)); Log(("PATMGC: IRET->VM stack frame: DS=%04X ES=%04X FS=%04X GS=%04X\n", selDS, selES, selFS, selGS)); } } else Log(("PATMGC: IRET stack frame: return address %04X:%VGv eflags=%08x ss:esp=%04X:%VGv\n", selCS, eip, uEFlags, selSS, esp)); } else Log(("PATMGC: IRET stack frame: return address %04X:%VGv eflags=%08x\n", selCS, eip, uEFlags)); } Log(("PATMGC: IRET from %VGv (IF->1) current eflags=%x\n", pRegFrame->eip, pVM->patm.s.CTXSUFF(pGCState)->uVMFlags)); pRegFrame->eip += PATM_ILLEGAL_INSTR_SIZE; return VINF_SUCCESS; } case PATM_ACTION_LOG_GATE_ENTRY: { char *pIretFrame = (char *)pRegFrame->edx; uint32_t eip, selCS, uEFlags; rc = MMGCRamRead(pVM, &eip, pIretFrame, 4); rc |= MMGCRamRead(pVM, &selCS, pIretFrame + 4, 4); rc |= MMGCRamRead(pVM, &uEFlags, pIretFrame + 8, 4); if (rc == VINF_SUCCESS) { if ( (uEFlags & X86_EFL_VM) || (selCS & X86_SEL_RPL) == 3) { uint32_t selSS, esp; rc |= MMGCRamRead(pVM, &esp, pIretFrame + 12, 4); rc |= MMGCRamRead(pVM, &selSS, pIretFrame + 16, 4); if (uEFlags & X86_EFL_VM) { uint32_t selDS, selES, selFS, selGS; rc = MMGCRamRead(pVM, &selES, pIretFrame + 20, 4); rc |= MMGCRamRead(pVM, &selDS, pIretFrame + 24, 4); rc |= MMGCRamRead(pVM, &selFS, pIretFrame + 28, 4); rc |= MMGCRamRead(pVM, &selGS, pIretFrame + 32, 4); if (rc == VINF_SUCCESS) { Log(("PATMGC: GATE->VM stack frame: return address %04X:%VGv eflags=%08x ss:esp=%04X:%VGv\n", selCS, eip, uEFlags, selSS, esp)); Log(("PATMGC: GATE->VM stack frame: DS=%04X ES=%04X FS=%04X GS=%04X\n", selDS, selES, selFS, selGS)); } } else Log(("PATMGC: GATE stack frame: return address %04X:%VGv eflags=%08x ss:esp=%04X:%VGv\n", selCS, eip, uEFlags, selSS, esp)); } else Log(("PATMGC: GATE stack frame: return address %04X:%VGv eflags=%08x\n", selCS, eip, uEFlags)); } pRegFrame->eip += PATM_ILLEGAL_INSTR_SIZE; return VINF_SUCCESS; } case PATM_ACTION_LOG_RET: Log(("PATMGC: RET to %VGv ESP=%VGv iopl=%d\n", pRegFrame->edx, pRegFrame->ebx, X86_EFL_GET_IOPL(pVM->patm.s.CTXSUFF(pGCState)->uVMFlags))); pRegFrame->eip += PATM_ILLEGAL_INSTR_SIZE; return VINF_SUCCESS; case PATM_ACTION_LOG_CALL: Log(("PATMGC: CALL to %VGv return addr %VGv ESP=%VGv iopl=%d\n", pVM->patm.s.CTXSUFF(pGCState)->GCCallPatchTargetAddr, pVM->patm.s.CTXSUFF(pGCState)->GCCallReturnAddr, pRegFrame->edx, X86_EFL_GET_IOPL(pVM->patm.s.CTXSUFF(pGCState)->uVMFlags))); pRegFrame->eip += PATM_ILLEGAL_INSTR_SIZE; return VINF_SUCCESS; #endif default: AssertFailed(); break; } } else AssertFailed(); CTXSUFF(pVM->patm.s.pGCState)->uPendingAction = 0; } AssertMsgFailed(("Unexpected OP_ILLUD2 in patch code at %VGv (pending action %x)!!!!\n", pRegFrame->eip, CTXSUFF(pVM->patm.s.pGCState)->uPendingAction)); return VINF_EM_RAW_EMULATE_INSTR; } /** * Checks if the int 3 was caused by a patched instruction * * @returns VBox status * * @param pVM The VM handle. * @param pCtxCore The relevant core context. */ PATMDECL(int) PATMHandleInt3PatchTrap(PVM pVM, PCPUMCTXCORE pRegFrame) { PPATMPATCHREC pRec; int rc; AssertReturn(!pRegFrame->eflags.Bits.u1VM && (pRegFrame->ss & X86_SEL_RPL) == 1, VERR_ACCESS_DENIED); /* Int 3 in PATM generated code? (most common case) */ if (PATMIsPatchGCAddr(pVM, (RTGCPTR)pRegFrame->eip)) { /* @note hardcoded assumption about it being a single byte int 3 instruction. */ pRegFrame->eip--; return VINF_PATM_PATCH_INT3; } /** @todo could use simple caching here to speed things up. */ pRec = (PPATMPATCHREC)RTAvloGCPtrGet(&CTXSUFF(pVM->patm.s.PatchLookupTree)->PatchTree, (RTGCPTR)(pRegFrame->eip - 1)); /* eip is pointing to the instruction *after* 'int 3' already */ if (pRec && pRec->patch.uState == PATCH_ENABLED) { if (pRec->patch.flags & PATMFL_INT3_REPLACEMENT_BLOCK) { Assert(pRec->patch.opcode == OP_CLI); /* This is a special cli block that was turned into an int 3 patch. We jump to the generated code manually. */ pRegFrame->eip = (uint32_t)PATCHCODE_PTR_GC(&pRec->patch); STAM_COUNTER_INC(&pVM->patm.s.StatInt3BlockRun); return VINF_SUCCESS; } else if (pRec->patch.flags & PATMFL_INT3_REPLACEMENT) { uint32_t size, cbOp; DISCPUSTATE cpu; /* eip is pointing to the instruction *after* 'int 3' already */ pRegFrame->eip = pRegFrame->eip - 1; PATM_STAT_RUN_INC(&pRec->patch); Log(("PATMHandleInt3PatchTrap found int3 for %s at %VGv\n", patmGetInstructionString(pRec->patch.opcode, 0), pRegFrame->eip)); switch(pRec->patch.opcode) { case OP_CPUID: case OP_IRET: break; case OP_STR: case OP_SGDT: case OP_SLDT: case OP_SIDT: case OP_LSL: case OP_LAR: case OP_SMSW: case OP_VERW: case OP_VERR: default: PATM_STAT_FAULT_INC(&pRec->patch); pRec->patch.cTraps++; return VINF_EM_RAW_EMULATE_INSTR; } cpu.mode = SELMIsSelector32Bit(pVM, pRegFrame->eflags, pRegFrame->cs, 0) ? CPUMODE_32BIT : CPUMODE_16BIT; if(cpu.mode != CPUMODE_32BIT) { AssertFailed(); return VINF_EM_RAW_EMULATE_INSTR; } rc = DISCoreOne(&cpu, (RTUINTPTR)&pRec->patch.aPrivInstr[0], &cbOp); if (VBOX_FAILURE(rc)) { Log(("DISCoreOne failed with %Vrc\n", rc)); PATM_STAT_FAULT_INC(&pRec->patch); pRec->patch.cTraps++; return VINF_EM_RAW_EMULATE_INSTR; } rc = EMInterpretInstructionCPU(pVM, &cpu, pRegFrame, 0 /* not relevant here */, &size); if (rc != VINF_SUCCESS) { Log(("EMInterpretInstructionCPU failed with %Vrc\n", rc)); PATM_STAT_FAULT_INC(&pRec->patch); pRec->patch.cTraps++; return VINF_EM_RAW_EMULATE_INSTR; } pRegFrame->eip += cpu.opsize; return VINF_SUCCESS; } } return VERR_PATCH_NOT_FOUND; }