/* $Id: DBGFRZ.cpp $ */ /** @file * DBGF - Debugger Facility, RZ part. */ /* * Copyright (C) 2006-2020 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. */ /********************************************************************************************************************************* * Header Files * *********************************************************************************************************************************/ #define LOG_GROUP LOG_GROUP_DBGF #include #include #ifdef IN_RC # include #endif #include #include "DBGFInternal.h" #include #include #include #ifdef IN_RC DECLASM(void) TRPMRCHandlerAsmTrap03(void); #endif /** * \#DB (Debug event) handler. * * @returns VBox status code. * VINF_SUCCESS means we completely handled this trap, * other codes are passed execution to host context. * * @param pVM The cross context VM structure. * @param pVCpu The cross context virtual CPU structure. * @param pRegFrame Pointer to the register frame for the trap. * @param uDr6 The DR6 hypervisor register value. * @param fAltStepping Alternative stepping indicator. */ VMMRZ_INT_DECL(int) DBGFRZTrap01Handler(PVM pVM, PVMCPU pVCpu, PCPUMCTXCORE pRegFrame, RTGCUINTREG uDr6, bool fAltStepping) { #ifdef IN_RC const bool fInHyper = !(pRegFrame->ss.Sel & X86_SEL_RPL) && !pRegFrame->eflags.Bits.u1VM; #else NOREF(pRegFrame); const bool fInHyper = false; #endif /** @todo Intel docs say that X86_DR6_BS has the highest priority... */ /* * A breakpoint? */ AssertCompile(X86_DR6_B0 == 1 && X86_DR6_B1 == 2 && X86_DR6_B2 == 4 && X86_DR6_B3 == 8); if ( (uDr6 & (X86_DR6_B0 | X86_DR6_B1 | X86_DR6_B2 | X86_DR6_B3)) && pVM->dbgf.s.cEnabledHwBreakpoints > 0) { for (unsigned iBp = 0; iBp < RT_ELEMENTS(pVM->dbgf.s.aHwBreakpoints); iBp++) { if ( ((uint32_t)uDr6 & RT_BIT_32(iBp)) && pVM->dbgf.s.aHwBreakpoints[iBp].enmType == DBGFBPTYPE_REG) { pVCpu->dbgf.s.iActiveBp = pVM->dbgf.s.aHwBreakpoints[iBp].iBp; pVCpu->dbgf.s.fSingleSteppingRaw = false; LogFlow(("DBGFRZTrap03Handler: hit hw breakpoint %d at %04x:%RGv\n", pVM->dbgf.s.aHwBreakpoints[iBp].iBp, pRegFrame->cs.Sel, pRegFrame->rip)); return fInHyper ? VINF_EM_DBG_HYPER_BREAKPOINT : VINF_EM_DBG_BREAKPOINT; } } } /* * Single step? * Are we single stepping or is it the guest? */ if ( (uDr6 & X86_DR6_BS) && (fInHyper || pVCpu->dbgf.s.fSingleSteppingRaw || fAltStepping)) { pVCpu->dbgf.s.fSingleSteppingRaw = false; LogFlow(("DBGFRZTrap01Handler: single step at %04x:%RGv\n", pRegFrame->cs.Sel, pRegFrame->rip)); return fInHyper ? VINF_EM_DBG_HYPER_STEPPED : VINF_EM_DBG_STEPPED; } #ifdef IN_RC /* * Either an ICEBP in hypervisor code or a guest related debug exception * of sorts. */ if (RT_UNLIKELY(fInHyper)) { /* * Is this a guest debug event that was delayed past a ring transition? * * Since we do no allow sysenter/syscall in raw-mode, the only * non-trap/fault type transitions that can occur are thru interrupt gates. * Of those, only INT3 (#BP) has a DPL other than 0 with a CS.RPL of 0. * See bugref:9171 and bs3-cpu-weird-1 for more details. * * We need to reconstruct the guest register state from the hypervisor one * here, so here is the layout of the IRET frame on the stack: * 20:[8] GS (V86 only) * 1C:[7] FS (V86 only) * 18:[6] DS (V86 only) * 14:[5] ES (V86 only) * 10:[4] SS * 0c:[3] ESP * 08:[2] EFLAGS * 04:[1] CS * 00:[0] EIP */ if (pRegFrame->rip == (uintptr_t)TRPMRCHandlerAsmTrap03) { uint32_t const *pu32Stack = (uint32_t const *)pRegFrame->esp; if ( (pu32Stack[2] & X86_EFL_VM) || (pu32Stack[1] & X86_SEL_RPL)) { LogFlow(("DBGFRZTrap01Handler: Detected guest #DB delayed past ring transition %04x:%RX32 %#x\n", pu32Stack[1] & 0xffff, pu32Stack[0], pu32Stack[2])); PCPUMCTX pGstCtx = CPUMQueryGuestCtxPtr(pVCpu); pGstCtx->rip = pu32Stack[0]; pGstCtx->cs.Sel = pu32Stack[1]; pGstCtx->eflags.u = pu32Stack[2]; pGstCtx->rsp = pu32Stack[3]; pGstCtx->ss.Sel = pu32Stack[4]; if (pu32Stack[2] & X86_EFL_VM) { pGstCtx->es.Sel = pu32Stack[5]; pGstCtx->ds.Sel = pu32Stack[6]; pGstCtx->fs.Sel = pu32Stack[7]; pGstCtx->gs.Sel = pu32Stack[8]; } else { pGstCtx->es.Sel = pRegFrame->es.Sel; pGstCtx->ds.Sel = pRegFrame->ds.Sel; pGstCtx->fs.Sel = pRegFrame->fs.Sel; pGstCtx->gs.Sel = pRegFrame->gs.Sel; } pGstCtx->rax = pRegFrame->rax; pGstCtx->rcx = pRegFrame->rcx; pGstCtx->rdx = pRegFrame->rdx; pGstCtx->rbx = pRegFrame->rbx; pGstCtx->rsi = pRegFrame->rsi; pGstCtx->rdi = pRegFrame->rdi; pGstCtx->rbp = pRegFrame->rbp; /* * We should assert a #BP followed by a #DB here, but TRPM cannot * do that. So, we'll just assert the #BP and ignore the #DB, even * if that isn't strictly correct. */ TRPMResetTrap(pVCpu); TRPMAssertTrap(pVCpu, X86_XCPT_BP, TRPM_SOFTWARE_INT); return VINF_EM_RAW_GUEST_TRAP; } } LogFlow(("DBGFRZTrap01Handler: Unknown bp at %04x:%RGv\n", pRegFrame->cs.Sel, pRegFrame->rip)); return VERR_DBGF_HYPER_DB_XCPT; } #endif LogFlow(("DBGFRZTrap01Handler: guest debug event %#x at %04x:%RGv!\n", (uint32_t)uDr6, pRegFrame->cs.Sel, pRegFrame->rip)); return VINF_EM_RAW_GUEST_TRAP; } /** * \#BP (Breakpoint) handler. * * @returns VBox status code. * VINF_SUCCESS means we completely handled this trap, * other codes are passed execution to host context. * * @param pVM The cross context VM structure. * @param pVCpu The cross context virtual CPU structure. * @param pRegFrame Pointer to the register frame for the trap. */ VMMRZ_INT_DECL(int) DBGFRZTrap03Handler(PVM pVM, PVMCPU pVCpu, PCPUMCTXCORE pRegFrame) { #ifdef IN_RC const bool fInHyper = !(pRegFrame->ss.Sel & X86_SEL_RPL) && !pRegFrame->eflags.Bits.u1VM; #else const bool fInHyper = false; #endif /* * Get the trap address and look it up in the breakpoint table. * Don't bother if we don't have any breakpoints. */ unsigned cToSearch = pVM->dbgf.s.Int3.cToSearch; if (cToSearch > 0) { RTGCPTR pPc; int rc = SELMValidateAndConvertCSAddr(pVCpu, pRegFrame->eflags, pRegFrame->ss.Sel, pRegFrame->cs.Sel, &pRegFrame->cs, #ifdef IN_RC pRegFrame->eip - 1, #else pRegFrame->rip /* no -1 in R0 */, #endif &pPc); AssertRCReturn(rc, rc); unsigned iBp = pVM->dbgf.s.Int3.iStartSearch; while (cToSearch-- > 0) { if ( pVM->dbgf.s.aBreakpoints[iBp].u.GCPtr == (RTGCUINTPTR)pPc && pVM->dbgf.s.aBreakpoints[iBp].enmType == DBGFBPTYPE_INT3) { pVM->dbgf.s.aBreakpoints[iBp].cHits++; pVCpu->dbgf.s.iActiveBp = pVM->dbgf.s.aBreakpoints[iBp].iBp; LogFlow(("DBGFRZTrap03Handler: hit breakpoint %d at %RGv (%04x:%RGv) cHits=0x%RX64\n", pVM->dbgf.s.aBreakpoints[iBp].iBp, pPc, pRegFrame->cs.Sel, pRegFrame->rip, pVM->dbgf.s.aBreakpoints[iBp].cHits)); return fInHyper ? VINF_EM_DBG_HYPER_BREAKPOINT : VINF_EM_DBG_BREAKPOINT; } iBp++; } } return fInHyper ? VINF_EM_DBG_HYPER_ASSERTION : VINF_EM_RAW_GUEST_TRAP; }