/* $Id: DBGPlugInDarwin.cpp $ */ /** @file * DBGPlugInDarwin - Debugger and Guest OS Digger Plugin For Darwin / OS X. */ /* * Copyright (C) 2008-2019 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 /// @todo add new log group. #include "DBGPlugIns.h" #include #include #include #include #include #include #include #include /********************************************************************************************************************************* * Structures and Typedefs * *********************************************************************************************************************************/ /** @name Internal Darwin structures * @{ */ /** * 32-bit darwin kernel module info structure (kmod_info_t). */ typedef struct OSX32_kmod_info { uint32_t next; int32_t info_version; uint32_t id; char name[64]; char version[64]; int32_t reference_count; uint32_t reference_list; /**< Points to kmod_reference_t. */ uint32_t address; /**< Where in memory the kext is loaded. */ uint32_t size; uint32_t hdr_size; uint32_t start; /**< Address of kmod_start_func_t. */ uint32_t stop; /**< Address of kmod_stop_func_t. */ } OSX32_kmod_info_t; /** * 32-bit darwin kernel module info structure (kmod_info_t). */ #pragma pack(1) typedef struct OSX64_kmod_info { uint64_t next; int32_t info_version; uint32_t id; char name[64]; char version[64]; int32_t reference_count; uint64_t reference_list; /**< Points to kmod_reference_t. Misaligned, duh. */ uint64_t address; /**< Where in memory the kext is loaded. */ uint64_t size; uint64_t hdr_size; uint64_t start; /**< Address of kmod_start_func_t. */ uint64_t stop; /**< Address of kmod_stop_func_t. */ } OSX64_kmod_info_t; #pragma pack() /** The value of the info_version field. */ #define OSX_KMOD_INFO_VERSION INT32_C(1) /** @} */ /** * Linux guest OS digger instance data. */ typedef struct DBGDIGGERDARWIN { /** Whether the information is valid or not. * (For fending off illegal interface method calls.) */ bool fValid; /** Set if 64-bit kernel, clear if 32-bit. * Set during probing. */ bool f64Bit; /** The address of an kernel version string (there are several). * This is set during probing. */ DBGFADDRESS AddrKernelVersion; /** Kernel base address. * This is set during probing. */ DBGFADDRESS AddrKernel; /** The kernel message log interface. */ DBGFOSIDMESG IDmesg; } DBGDIGGERDARWIN; /** Pointer to the linux guest OS digger instance data. */ typedef DBGDIGGERDARWIN *PDBGDIGGERDARWIN; /********************************************************************************************************************************* * Defined Constants And Macros * *********************************************************************************************************************************/ /** Validates a 32-bit darwin kernel address */ #define OSX32_VALID_ADDRESS(Addr) ((Addr) > UINT32_C(0x00001000) && (Addr) < UINT32_C(0xfffff000)) /** Validates a 64-bit darwin kernel address */ #define OSX64_VALID_ADDRESS(Addr) ((Addr) > UINT64_C(0xffff800000000000) && (Addr) < UINT64_C(0xfffffffffffff000)) /** Validates a 32-bit or 64-bit darwin kernel address. */ #define OSX_VALID_ADDRESS(a_f64Bits, a_Addr) \ ((a_f64Bits) ? OSX64_VALID_ADDRESS(a_Addr) : OSX32_VALID_ADDRESS(a_Addr)) /** AppleOsX on little endian ASCII systems. */ #define DIG_DARWIN_MOD_TAG UINT64_C(0x58734f656c707041) /********************************************************************************************************************************* * Internal Functions * *********************************************************************************************************************************/ static DECLCALLBACK(int) dbgDiggerDarwinInit(PUVM pUVM, void *pvData); /** * @interface_method_impl{DBGFOSIDMESG,pfnQueryKernelLog} */ static DECLCALLBACK(int) dbgDiggerDarwinIDmsg_QueryKernelLog(PDBGFOSIDMESG pThis, PUVM pUVM, uint32_t fFlags, uint32_t cMessages, char *pszBuf, size_t cbBuf, size_t *pcbActual) { RT_NOREF1(fFlags); PDBGDIGGERDARWIN pData = RT_FROM_MEMBER(pThis, DBGDIGGERDARWIN, IDmesg); if (cMessages < 1) return VERR_INVALID_PARAMETER; /* * The 'msgbufp' variable points to a struct msgbuf (bsd/kern/subr_log.c). */ RTDBGAS hAs = DBGFR3AsResolveAndRetain(pUVM, DBGF_AS_KERNEL); RTDBGMOD hMod; int rc = RTDbgAsModuleByName(hAs, "mach_kernel", 0, &hMod); if (RT_FAILURE(rc)) return VERR_NOT_FOUND; RTDbgAsRelease(hAs); DBGFADDRESS Addr; RTGCPTR GCPtrMsgBufP = 0; RTDBGSYMBOL SymInfo; rc = RTDbgModSymbolByName(hMod, "_msgbufp", &SymInfo); if (RT_SUCCESS(rc)) { rc = DBGFR3MemRead(pUVM, 0 /*idCpu*/, DBGFR3AddrFromFlat(pUVM, &Addr, SymInfo.Value + pData->AddrKernel.FlatPtr), &GCPtrMsgBufP, pData->f64Bit ? sizeof(uint64_t) : sizeof(uint32_t)); if (RT_FAILURE(rc)) { Log(("dbgDiggerDarwinIDmsg_QueryKernelLog: failed to read _msgbufp at %RGv: %Rrc\n", Addr.FlatPtr, rc)); return VERR_NOT_FOUND; } if (!OSX_VALID_ADDRESS(pData->f64Bit, GCPtrMsgBufP)) { Log(("dbgDiggerDarwinIDmsg_QueryKernelLog: Invalid address for _msgbufp: %RGv\n", GCPtrMsgBufP)); return VERR_NOT_FOUND; } } else { rc = RTDbgModSymbolByName(hMod, "_msgbuf", &SymInfo); if (RT_FAILURE(rc)) { Log(("dbgDiggerDarwinIDmsg_QueryKernelLog: failed to find _msgbufp and _msgbuf: %Rrc\n", rc)); return VERR_NOT_FOUND; } GCPtrMsgBufP = SymInfo.Value + pData->AddrKernel.FlatPtr; if (!OSX_VALID_ADDRESS(pData->f64Bit, GCPtrMsgBufP)) { Log(("dbgDiggerDarwinIDmsg_QueryKernelLog: Invalid address for _msgbuf: %RGv\n", GCPtrMsgBufP)); return VERR_NOT_FOUND; } } /* * Read the msgbuf structure. */ struct { uint32_t msg_magic; uint32_t msg_size; uint32_t msg_bufx; uint32_t msg_bufr; uint64_t msg_bufc; /**< Size depends on windows size. */ } MsgBuf; rc = DBGFR3MemRead(pUVM, 0 /*idCpu*/, DBGFR3AddrFromFlat(pUVM, &Addr, GCPtrMsgBufP), &MsgBuf, sizeof(MsgBuf) - (pData->f64Bit ? 0 : sizeof(uint32_t)) ); if (RT_FAILURE(rc)) { Log(("dbgDiggerDarwinIDmsg_QueryKernelLog: failed to read msgbuf struct at %RGv: %Rrc\n", Addr.FlatPtr, rc)); return VERR_NOT_FOUND; } if (!pData->f64Bit) MsgBuf.msg_bufc &= UINT32_MAX; /* * Validate the structure. */ if ( MsgBuf.msg_magic != UINT32_C(0x63061) || MsgBuf.msg_size < UINT32_C(4096) || MsgBuf.msg_size > 16*_1M || MsgBuf.msg_bufx > MsgBuf.msg_size || MsgBuf.msg_bufr > MsgBuf.msg_size || !OSX_VALID_ADDRESS(pData->f64Bit, MsgBuf.msg_bufc) ) { Log(("dbgDiggerDarwinIDmsg_QueryKernelLog: Invalid MsgBuf data: magic=%#x size=%#x bufx=%#x bufr=%#x bufc=%RGv\n", MsgBuf.msg_magic, MsgBuf.msg_size, MsgBuf.msg_bufx, MsgBuf.msg_bufr, MsgBuf.msg_bufc)); return VERR_INVALID_STATE; } /* * Read the buffer. */ char *pchMsgBuf = (char *)RTMemAlloc(MsgBuf.msg_size); if (!pchMsgBuf) { Log(("dbgDiggerDarwinIDmsg_QueryKernelLog: Failed to allocate %#x bytes of memory for the log buffer\n", MsgBuf.msg_size)); return VERR_INVALID_STATE; } rc = DBGFR3MemRead(pUVM, 0 /*idCpu*/, DBGFR3AddrFromFlat(pUVM, &Addr, MsgBuf.msg_bufc), pchMsgBuf, MsgBuf.msg_size); if (RT_SUCCESS(rc)) { /* * Copy it out raw. */ uint32_t offDst = 0; if (MsgBuf.msg_bufr < MsgBuf.msg_bufx) { /* Single chunk between the read and write offsets. */ uint32_t cbToCopy = MsgBuf.msg_bufx - MsgBuf.msg_bufr; if (cbToCopy < cbBuf) { memcpy(pszBuf, &pchMsgBuf[MsgBuf.msg_bufr], cbToCopy); pszBuf[cbToCopy] = '\0'; rc = VINF_SUCCESS; } else { if (cbBuf) { memcpy(pszBuf, &pchMsgBuf[MsgBuf.msg_bufr], cbBuf - 1); pszBuf[cbBuf - 1] = '\0'; } rc = VERR_BUFFER_OVERFLOW; } offDst = cbToCopy + 1; } else { /* Two chunks, read offset to end, start to write offset. */ uint32_t cbFirst = MsgBuf.msg_size - MsgBuf.msg_bufr; uint32_t cbSecond = MsgBuf.msg_bufx; if (cbFirst + cbSecond < cbBuf) { memcpy(pszBuf, &pchMsgBuf[MsgBuf.msg_bufr], cbFirst); memcpy(&pszBuf[cbFirst], pchMsgBuf, cbSecond); offDst = cbFirst + cbSecond; pszBuf[offDst++] = '\0'; rc = VINF_SUCCESS; } else { offDst = cbFirst + cbSecond + 1; if (cbFirst < cbBuf) { memcpy(pszBuf, &pchMsgBuf[MsgBuf.msg_bufr], cbFirst); memcpy(&pszBuf[cbFirst], pchMsgBuf, cbBuf - cbFirst); pszBuf[cbBuf - 1] = '\0'; } else if (cbBuf) { memcpy(pszBuf, &pchMsgBuf[MsgBuf.msg_bufr], cbBuf - 1); pszBuf[cbBuf - 1] = '\0'; } rc = VERR_BUFFER_OVERFLOW; } } if (pcbActual) *pcbActual = offDst; } else Log(("dbgDiggerDarwinIDmsg_QueryKernelLog: Error reading %#x bytes at %RGv: %Rrc\n", MsgBuf.msg_size, MsgBuf.msg_bufc, rc)); RTMemFree(pchMsgBuf); return rc; } /** * @copydoc DBGFOSREG::pfnStackUnwindAssist */ static DECLCALLBACK(int) dbgDiggerDarwinStackUnwindAssist(PUVM pUVM, void *pvData, VMCPUID idCpu, PDBGFSTACKFRAME pFrame, PRTDBGUNWINDSTATE pState, PCCPUMCTX pInitialCtx, RTDBGAS hAs, uint64_t *puScratch) { RT_NOREF(pUVM, pvData, idCpu, pFrame, pState, pInitialCtx, hAs, puScratch); return VINF_SUCCESS; } /** * @copydoc DBGFOSREG::pfnQueryInterface */ static DECLCALLBACK(void *) dbgDiggerDarwinQueryInterface(PUVM pUVM, void *pvData, DBGFOSINTERFACE enmIf) { RT_NOREF1(pUVM); PDBGDIGGERDARWIN pThis = (PDBGDIGGERDARWIN)pvData; switch (enmIf) { case DBGFOSINTERFACE_DMESG: return &pThis->IDmesg; default: return NULL; } } /** * @copydoc DBGFOSREG::pfnQueryVersion */ static DECLCALLBACK(int) dbgDiggerDarwinQueryVersion(PUVM pUVM, void *pvData, char *pszVersion, size_t cchVersion) { PDBGDIGGERDARWIN pThis = (PDBGDIGGERDARWIN)pvData; Assert(pThis->fValid); /* * It's all in the linux banner. */ int rc = DBGFR3MemReadString(pUVM, 0, &pThis->AddrKernelVersion, pszVersion, cchVersion); if (RT_SUCCESS(rc)) { char *pszEnd = RTStrEnd(pszVersion, cchVersion); AssertReturn(pszEnd, VERR_BUFFER_OVERFLOW); while ( pszEnd > pszVersion && RT_C_IS_SPACE(pszEnd[-1])) pszEnd--; *pszEnd = '\0'; } else RTStrPrintf(pszVersion, cchVersion, "DBGFR3MemRead -> %Rrc", rc); return rc; } /** * @copydoc DBGFOSREG::pfnTerm */ static DECLCALLBACK(void) dbgDiggerDarwinTerm(PUVM pUVM, void *pvData) { RT_NOREF1(pUVM); PDBGDIGGERDARWIN pThis = (PDBGDIGGERDARWIN)pvData; pThis->fValid = false; } /** * @copydoc DBGFOSREG::pfnRefresh */ static DECLCALLBACK(int) dbgDiggerDarwinRefresh(PUVM pUVM, void *pvData) { PDBGDIGGERDARWIN pThis = (PDBGDIGGERDARWIN)pvData; NOREF(pThis); Assert(pThis->fValid); /* * For now we'll flush and reload everything. */ dbgDiggerDarwinTerm(pUVM, pvData); return dbgDiggerDarwinInit(pUVM, pvData); } /** * Helper function that validates a segment (or section) name. * * @returns true if valid, false if not. * @param pszName The name string. * @param cbName The size of the string, including terminator. */ static bool dbgDiggerDarwinIsValidSegOrSectName(const char *pszName, size_t cbName) { /* ascii chars */ char ch; size_t off = 0; while (off < cbName && (ch = pszName[off])) { if (RT_C_IS_CNTRL(ch) || ch >= 127) return false; off++; } /* Not empty nor 100% full. */ if (off == 0 || off == cbName) return false; /* remainder should be zeros. */ while (off < cbName) { if (pszName[off]) return false; off++; } return true; } static int dbgDiggerDarwinAddModule(PDBGDIGGERDARWIN pThis, PUVM pUVM, uint64_t uModAddr, const char *pszName, bool *pf64Bit) { RT_NOREF1(pThis); union { uint8_t ab[2 * X86_PAGE_4K_SIZE]; mach_header_64_t Hdr64; mach_header_32_t Hdr32; } uBuf; /* Read the first page of the image. */ DBGFADDRESS ModAddr; int rc = DBGFR3MemRead(pUVM, 0 /*idCpu*/, DBGFR3AddrFromFlat(pUVM, &ModAddr, uModAddr), uBuf.ab, X86_PAGE_4K_SIZE); if (RT_FAILURE(rc)) return rc; /* Validate the header. */ AssertCompileMembersSameSizeAndOffset(mach_header_64_t, magic, mach_header_32_t, magic); if ( uBuf.Hdr64.magic != IMAGE_MACHO64_SIGNATURE && uBuf.Hdr32.magic != IMAGE_MACHO32_SIGNATURE) return VERR_INVALID_EXE_SIGNATURE; AssertCompileMembersSameSizeAndOffset(mach_header_64_t, cputype, mach_header_32_t, cputype); bool f64Bit = uBuf.Hdr64.magic == IMAGE_MACHO64_SIGNATURE; if (uBuf.Hdr32.cputype != (f64Bit ? CPU_TYPE_X86_64 : CPU_TYPE_I386)) return VERR_LDR_ARCH_MISMATCH; AssertCompileMembersSameSizeAndOffset(mach_header_64_t, filetype, mach_header_32_t, filetype); if ( uBuf.Hdr32.filetype != MH_EXECUTE && uBuf.Hdr32.filetype != (f64Bit ? MH_KEXT_BUNDLE : MH_OBJECT)) return VERR_BAD_EXE_FORMAT; AssertCompileMembersSameSizeAndOffset(mach_header_64_t, ncmds, mach_header_32_t, ncmds); if (uBuf.Hdr32.ncmds > 256) return VERR_BAD_EXE_FORMAT; AssertCompileMembersSameSizeAndOffset(mach_header_64_t, sizeofcmds, mach_header_32_t, sizeofcmds); if (uBuf.Hdr32.sizeofcmds > X86_PAGE_4K_SIZE * 2 - sizeof(mach_header_64_t)) return VERR_BAD_EXE_FORMAT; /* Do we need to read a 2nd page to get all the load commands? If so, do it. */ if (uBuf.Hdr32.sizeofcmds + (f64Bit ? sizeof(mach_header_64_t) : sizeof(mach_header_32_t)) > X86_PAGE_4K_SIZE) { rc = DBGFR3MemRead(pUVM, 0 /*idCpu*/, DBGFR3AddrFromFlat(pUVM, &ModAddr, uModAddr + X86_PAGE_4K_SIZE), &uBuf.ab[X86_PAGE_4K_SIZE], X86_PAGE_4K_SIZE); if (RT_FAILURE(rc)) return rc; } /* * Process the load commands. */ RTDBGSEGMENT aSegs[24]; uint32_t cSegs = 0; RTUUID Uuid = RTUUID_INITIALIZE_NULL; uint32_t cLeft = uBuf.Hdr32.ncmds; uint32_t cbLeft = uBuf.Hdr32.sizeofcmds; union { uint8_t const *pb; load_command_t const *pGenric; segment_command_32_t const *pSeg32; segment_command_64_t const *pSeg64; section_32_t const *pSect32; section_64_t const *pSect64; symtab_command_t const *pSymTab; uuid_command_t const *pUuid; } uLCmd; uLCmd.pb = &uBuf.ab[f64Bit ? sizeof(mach_header_64_t) : sizeof(mach_header_32_t)]; while (cLeft-- > 0) { uint32_t const cbCmd = uLCmd.pGenric->cmdsize; if (cbCmd > cbLeft || cbCmd < sizeof(load_command_t)) return VERR_BAD_EXE_FORMAT; switch (uLCmd.pGenric->cmd) { case LC_SEGMENT_32: if (cbCmd != sizeof(segment_command_32_t) + uLCmd.pSeg32->nsects * sizeof(section_32_t)) return VERR_BAD_EXE_FORMAT; if (!dbgDiggerDarwinIsValidSegOrSectName(uLCmd.pSeg32->segname, sizeof(uLCmd.pSeg32->segname))) return VERR_INVALID_NAME; if (!strcmp(uLCmd.pSeg32->segname, "__LINKEDIT")) break; /* This usually is discarded or not loaded at all. */ if (cSegs >= RT_ELEMENTS(aSegs)) return VERR_BUFFER_OVERFLOW; aSegs[cSegs].Address = uLCmd.pSeg32->vmaddr; aSegs[cSegs].uRva = uLCmd.pSeg32->vmaddr - uModAddr; aSegs[cSegs].cb = uLCmd.pSeg32->vmsize; aSegs[cSegs].fFlags = uLCmd.pSeg32->flags; /* Abusing the flags field here... */ aSegs[cSegs].iSeg = cSegs; AssertCompile(RTDBG_SEGMENT_NAME_LENGTH > sizeof(uLCmd.pSeg32->segname)); strcpy(aSegs[cSegs].szName, uLCmd.pSeg32->segname); cSegs++; break; case LC_SEGMENT_64: if (cbCmd != sizeof(segment_command_64_t) + uLCmd.pSeg64->nsects * sizeof(section_64_t)) return VERR_BAD_EXE_FORMAT; if (!dbgDiggerDarwinIsValidSegOrSectName(uLCmd.pSeg64->segname, sizeof(uLCmd.pSeg64->segname))) return VERR_INVALID_NAME; if (!strcmp(uLCmd.pSeg64->segname, "__LINKEDIT")) break; /* This usually is discarded or not loaded at all. */ if (cSegs >= RT_ELEMENTS(aSegs)) return VERR_BUFFER_OVERFLOW; aSegs[cSegs].Address = uLCmd.pSeg64->vmaddr; aSegs[cSegs].uRva = uLCmd.pSeg64->vmaddr - uModAddr; aSegs[cSegs].cb = uLCmd.pSeg64->vmsize; aSegs[cSegs].fFlags = uLCmd.pSeg64->flags; /* Abusing the flags field here... */ aSegs[cSegs].iSeg = cSegs; AssertCompile(RTDBG_SEGMENT_NAME_LENGTH > sizeof(uLCmd.pSeg64->segname)); strcpy(aSegs[cSegs].szName, uLCmd.pSeg64->segname); cSegs++; break; case LC_UUID: if (cbCmd != sizeof(uuid_command_t)) return VERR_BAD_EXE_FORMAT; if (RTUuidIsNull((PCRTUUID)&uLCmd.pUuid->uuid[0])) return VERR_BAD_EXE_FORMAT; memcpy(&Uuid, &uLCmd.pUuid->uuid[0], sizeof(uLCmd.pUuid->uuid)); break; default: /* Current known max plus a lot of slack. */ if (uLCmd.pGenric->cmd > LC_DYLIB_CODE_SIGN_DRS + 32) return VERR_BAD_EXE_FORMAT; break; } /* next */ cbLeft -= cbCmd; uLCmd.pb += cbCmd; } if (cbLeft != 0) return VERR_BAD_EXE_FORMAT; /* * Some post processing checks. */ uint32_t iSeg; for (iSeg = 0; iSeg < cSegs; iSeg++) if (aSegs[iSeg].Address == uModAddr) break; if (iSeg >= cSegs) return VERR_ADDRESS_CONFLICT; /* * Create a debug module. */ RTDBGMOD hMod; rc = RTDbgModCreateFromMachOImage(&hMod, pszName, NULL, f64Bit ? RTLDRARCH_AMD64 : RTLDRARCH_X86_32, 0 /*cbImage*/, cSegs, aSegs, &Uuid, DBGFR3AsGetConfig(pUVM), RTDBGMOD_F_NOT_DEFERRED); if (RT_FAILURE(rc)) { /* * Final fallback is a container module. */ rc = RTDbgModCreate(&hMod, pszName, 0, 0); if (RT_FAILURE(rc)) return rc; uint64_t uRvaNext = 0; for (iSeg = 0; iSeg < cSegs && RT_SUCCESS(rc); iSeg++) { if ( aSegs[iSeg].uRva > uRvaNext && aSegs[iSeg].uRva - uRvaNext < _1M) uRvaNext = aSegs[iSeg].uRva; rc = RTDbgModSegmentAdd(hMod, aSegs[iSeg].uRva, aSegs[iSeg].cb, aSegs[iSeg].szName, 0, NULL); if (aSegs[iSeg].cb > 0 && RT_SUCCESS(rc)) { char szTmp[RTDBG_SEGMENT_NAME_LENGTH + sizeof("_start")]; strcat(strcpy(szTmp, aSegs[iSeg].szName), "_start"); rc = RTDbgModSymbolAdd(hMod, szTmp, iSeg, 0 /*uRva*/, 0 /*cb*/, 0 /*fFlags*/, NULL); } uRvaNext += aSegs[iSeg].cb; } if (RT_FAILURE(rc)) { RTDbgModRelease(hMod); return rc; } } /* Tag the module. */ rc = RTDbgModSetTag(hMod, DIG_DARWIN_MOD_TAG); AssertRC(rc); /* * Link the module. */ RTDBGAS hAs = DBGFR3AsResolveAndRetain(pUVM, DBGF_AS_KERNEL); if (hAs != NIL_RTDBGAS) { //uint64_t uRvaNext = 0; - what was this? uint32_t cLinked = 0; iSeg = cSegs; while (iSeg-- > 0) /* HACK: Map in reverse order to avoid replacing __TEXT. */ if (aSegs[iSeg].cb) { /* Find matching segment in the debug module. */ uint32_t iDbgSeg = 0; while (iDbgSeg < cSegs) { RTDBGSEGMENT SegInfo; int rc3 = RTDbgModSegmentByIndex(hMod, iDbgSeg, &SegInfo); if (RT_SUCCESS(rc3) && !strcmp(SegInfo.szName, aSegs[iSeg].szName)) break; iDbgSeg++; } AssertMsgStmt(iDbgSeg < cSegs, ("%s\n", aSegs[iSeg].szName), continue); /* Map it. */ int rc2 = RTDbgAsModuleLinkSeg(hAs, hMod, iDbgSeg, aSegs[iSeg].Address, RTDBGASLINK_FLAGS_REPLACE /*fFlags*/); if (RT_SUCCESS(rc2)) cLinked++; else if (RT_SUCCESS(rc)) rc = rc2; } if (RT_FAILURE(rc) && cLinked != 0) rc = -rc; } else rc = VERR_INTERNAL_ERROR; RTDbgModRelease(hMod); RTDbgAsRelease(hAs); if (pf64Bit) *pf64Bit = f64Bit; return rc; } static bool dbgDiggerDarwinIsValidName(const char *pszName) { char ch; while ((ch = *pszName++) != '\0') { if (ch < 0x20 || ch >= 127) return false; } return true; } static bool dbgDiggerDarwinIsValidVersion(const char *pszVersion) { char ch; while ((ch = *pszVersion++) != '\0') { if (ch < 0x20 || ch >= 127) return false; } return true; } /** * @copydoc DBGFOSREG::pfnInit */ static DECLCALLBACK(int) dbgDiggerDarwinInit(PUVM pUVM, void *pvData) { PDBGDIGGERDARWIN pThis = (PDBGDIGGERDARWIN)pvData; Assert(!pThis->fValid); /* * Add the kernel module. */ bool f64Bit; int rc = dbgDiggerDarwinAddModule(pThis, pUVM, pThis->AddrKernel.FlatPtr, "mach_kernel", &f64Bit); if (RT_SUCCESS(rc)) { /* * The list of modules can be found at the 'kmod' symbol, that means * that we currently require some kind of symbol file for the kernel * to be loaded at this point. * * Note! Could also use the 'gLoadedKextSummaries', but I don't think * it's any easier to find without any kernel map than 'kmod'. */ RTDBGSYMBOL SymInfo; rc = DBGFR3AsSymbolByName(pUVM, DBGF_AS_KERNEL, "mach_kernel!kmod", &SymInfo, NULL); if (RT_FAILURE(rc)) rc = DBGFR3AsSymbolByName(pUVM, DBGF_AS_KERNEL, "mach_kernel!_kmod", &SymInfo, NULL); if (RT_SUCCESS(rc)) { DBGFADDRESS AddrModInfo; DBGFR3AddrFromFlat(pUVM, &AddrModInfo, SymInfo.Value); /* Read the variable. */ RTUINT64U uKmodValue = { 0 }; if (f64Bit) rc = DBGFR3MemRead(pUVM, 0 /*idCpu*/, &AddrModInfo, &uKmodValue.u, sizeof(uKmodValue.u)); else rc = DBGFR3MemRead (pUVM, 0 /*idCpu*/, &AddrModInfo, &uKmodValue.s.Lo, sizeof(uKmodValue.s.Lo)); if (RT_SUCCESS(rc)) { DBGFR3AddrFromFlat(pUVM, &AddrModInfo, uKmodValue.u); /* Walk the list of modules. */ uint32_t cIterations = 0; while (AddrModInfo.FlatPtr != 0) { /* Some extra loop conditions... */ if (!OSX_VALID_ADDRESS(f64Bit, AddrModInfo.FlatPtr)) { Log(("OSXDig: Invalid kmod_info pointer: %RGv\n", AddrModInfo.FlatPtr)); break; } if (AddrModInfo.FlatPtr == uKmodValue.u && cIterations != 0) { Log(("OSXDig: kmod_info list looped back to the start.\n")); break; } if (cIterations++ >= 2048) { Log(("OSXDig: Too many mod_info loops (%u)\n", cIterations)); break; } /* * Read the kmod_info_t structure. */ union { OSX64_kmod_info_t Info64; OSX32_kmod_info_t Info32; } uMod; RT_ZERO(uMod); rc = DBGFR3MemRead(pUVM, 0 /*idCpu*/, &AddrModInfo, &uMod, f64Bit ? sizeof(uMod.Info64) : sizeof(uMod.Info32)); if (RT_FAILURE(rc)) { Log(("OSXDig: Error reading kmod_info structure at %RGv: %Rrc\n", AddrModInfo.FlatPtr, rc)); break; } /* * Validate the kmod_info_t structure. */ int32_t iInfoVer = f64Bit ? uMod.Info64.info_version : uMod.Info32.info_version; if (iInfoVer != OSX_KMOD_INFO_VERSION) { Log(("OSXDig: kmod_info @%RGv: Bad info_version %d\n", AddrModInfo.FlatPtr, iInfoVer)); break; } const char *pszName = f64Bit ? uMod.Info64.name : uMod.Info32.name; if ( !*pszName || !RTStrEnd(pszName, sizeof(uMod.Info64.name)) || !dbgDiggerDarwinIsValidName(pszName) ) { Log(("OSXDig: kmod_info @%RGv: Bad name '%.*s'\n", AddrModInfo.FlatPtr, sizeof(uMod.Info64.name), pszName)); break; } const char *pszVersion = f64Bit ? uMod.Info64.version : uMod.Info32.version; if ( !RTStrEnd(pszVersion, sizeof(uMod.Info64.version)) || !dbgDiggerDarwinIsValidVersion(pszVersion) ) { Log(("OSXDig: kmod_info @%RGv: Bad version '%.*s'\n", AddrModInfo.FlatPtr, sizeof(uMod.Info64.version), pszVersion)); break; } int32_t cRefs = f64Bit ? uMod.Info64.reference_count : uMod.Info32.reference_count; if (cRefs < -1 || cRefs > 16384) { Log(("OSXDig: kmod_info @%RGv: Bad reference_count %d\n", AddrModInfo.FlatPtr, cRefs)); break; } uint64_t uImageAddr = f64Bit ? uMod.Info64.address : uMod.Info32.address; if (!OSX_VALID_ADDRESS(f64Bit, uImageAddr)) { Log(("OSXDig: kmod_info @%RGv: Bad address %#llx\n", AddrModInfo.FlatPtr, uImageAddr)); break; } uint64_t cbImage = f64Bit ? uMod.Info64.size : uMod.Info32.size; if (cbImage > 64U*_1M) { Log(("OSXDig: kmod_info @%RGv: Bad size %#llx\n", AddrModInfo.FlatPtr, cbImage)); break; } uint64_t cbHdr = f64Bit ? uMod.Info64.hdr_size : uMod.Info32.hdr_size; if (cbHdr > 16U*_1M) { Log(("OSXDig: kmod_info @%RGv: Bad hdr_size %#llx\n", AddrModInfo.FlatPtr, cbHdr)); break; } uint64_t uStartAddr = f64Bit ? uMod.Info64.start : uMod.Info32.start; if (!uStartAddr && !OSX_VALID_ADDRESS(f64Bit, uStartAddr)) { Log(("OSXDig: kmod_info @%RGv: Bad start function %#llx\n", AddrModInfo.FlatPtr, uStartAddr)); break; } uint64_t uStopAddr = f64Bit ? uMod.Info64.stop : uMod.Info32.stop; if (!uStopAddr && !OSX_VALID_ADDRESS(f64Bit, uStopAddr)) { Log(("OSXDig: kmod_info @%RGv: Bad stop function %#llx\n", AddrModInfo.FlatPtr, uStopAddr)); break; } /* * Try add the module. */ Log(("OSXDig: kmod_info @%RGv: '%s' ver '%s', image @%#llx LB %#llx cbHdr=%#llx\n", AddrModInfo.FlatPtr, pszName, pszVersion, uImageAddr, cbImage, cbHdr)); rc = dbgDiggerDarwinAddModule(pThis, pUVM, uImageAddr, pszName, NULL); /* * Advance to the next kmod_info entry. */ DBGFR3AddrFromFlat(pUVM, &AddrModInfo, f64Bit ? uMod.Info64.next : uMod.Info32.next); } } else Log(("OSXDig: Error reading the 'kmod' variable: %Rrc\n", rc)); } else Log(("OSXDig: Failed to locate the 'kmod' variable in mach_kernel.\n")); pThis->fValid = true; return VINF_SUCCESS; } return rc; } /** * @copydoc DBGFOSREG::pfnProbe */ static DECLCALLBACK(bool) dbgDiggerDarwinProbe(PUVM pUVM, void *pvData) { PDBGDIGGERDARWIN pThis = (PDBGDIGGERDARWIN)pvData; /* * Look for a section + segment combo that normally only occures in * mach_kernel. Follow it up with probing of the rest of the executable * header. We must search a largish area because the more recent versions * of darwin have random load address for security raisins. */ static struct { uint64_t uStart, uEnd; } const s_aRanges[] = { /* 64-bit: */ { UINT64_C(0xffffff8000000000), UINT64_C(0xffffff81ffffffff), }, /* 32-bit - always search for this because of the hybrid 32-bit kernel with cpu in long mode that darwin used for a number of versions. */ { UINT64_C(0x00001000), UINT64_C(0x0ffff000), } }; for (unsigned iRange = DBGFR3CpuGetMode(pUVM, 0 /*idCpu*/) != CPUMMODE_LONG; iRange < RT_ELEMENTS(s_aRanges); iRange++) { DBGFADDRESS KernelAddr; for (DBGFR3AddrFromFlat(pUVM, &KernelAddr, s_aRanges[iRange].uStart); KernelAddr.FlatPtr < s_aRanges[iRange].uEnd; KernelAddr.FlatPtr += X86_PAGE_4K_SIZE) { static const uint8_t s_abNeedle[16 + 16] = { '_','_','t','e','x','t', 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, /* section_32_t::sectname */ '_','_','K','L','D', 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, /* section_32_t::segname. */ }; int rc = DBGFR3MemScan(pUVM, 0 /*idCpu*/, &KernelAddr, s_aRanges[iRange].uEnd - KernelAddr.FlatPtr, 1, s_abNeedle, sizeof(s_abNeedle), &KernelAddr); if (RT_FAILURE(rc)) break; DBGFR3AddrSub(&KernelAddr, KernelAddr.FlatPtr & X86_PAGE_4K_OFFSET_MASK); /* * Read the first page of the image and check the headers. */ union { uint8_t ab[X86_PAGE_4K_SIZE]; mach_header_64_t Hdr64; mach_header_32_t Hdr32; } uBuf; rc = DBGFR3MemRead(pUVM, 0 /*idCpu*/, &KernelAddr, uBuf.ab, X86_PAGE_4K_SIZE); if (RT_FAILURE(rc)) continue; AssertCompileMembersSameSizeAndOffset(mach_header_64_t, magic, mach_header_32_t, magic); if ( uBuf.Hdr64.magic != IMAGE_MACHO64_SIGNATURE && uBuf.Hdr32.magic != IMAGE_MACHO32_SIGNATURE) continue; AssertCompileMembersSameSizeAndOffset(mach_header_64_t, cputype, mach_header_32_t, cputype); bool f64Bit = uBuf.Hdr64.magic == IMAGE_MACHO64_SIGNATURE; if (uBuf.Hdr32.cputype != (f64Bit ? CPU_TYPE_X86_64 : CPU_TYPE_I386)) continue; AssertCompileMembersSameSizeAndOffset(mach_header_64_t, filetype, mach_header_32_t, filetype); if (uBuf.Hdr32.filetype != MH_EXECUTE) continue; AssertCompileMembersSameSizeAndOffset(mach_header_64_t, ncmds, mach_header_32_t, ncmds); if (uBuf.Hdr32.ncmds > 256) continue; AssertCompileMembersSameSizeAndOffset(mach_header_64_t, sizeofcmds, mach_header_32_t, sizeofcmds); if (uBuf.Hdr32.sizeofcmds > X86_PAGE_4K_SIZE * 2 - sizeof(mach_header_64_t)) continue; /* Seems good enough for now. If the above causes false positives, check the segments and make sure there is a kernel version string in the right one. */ pThis->AddrKernel = KernelAddr; pThis->f64Bit = f64Bit; /* * Finally, find the kernel version string. */ rc = DBGFR3MemScan(pUVM, 0 /*idCpu*/, &KernelAddr, 32*_1M, 1, RT_STR_TUPLE("Darwin Kernel Version"), &pThis->AddrKernelVersion); if (RT_FAILURE(rc)) DBGFR3AddrFromFlat(pUVM, &pThis->AddrKernelVersion, 0); return true; } } return false; } /** * @copydoc DBGFOSREG::pfnDestruct */ static DECLCALLBACK(void) dbgDiggerDarwinDestruct(PUVM pUVM, void *pvData) { RT_NOREF2(pUVM, pvData); } /** * @copydoc DBGFOSREG::pfnConstruct */ static DECLCALLBACK(int) dbgDiggerDarwinConstruct(PUVM pUVM, void *pvData) { RT_NOREF1(pUVM); PDBGDIGGERDARWIN pThis = (PDBGDIGGERDARWIN)pvData; pThis->IDmesg.u32Magic = DBGFOSIDMESG_MAGIC; pThis->IDmesg.pfnQueryKernelLog = dbgDiggerDarwinIDmsg_QueryKernelLog; pThis->IDmesg.u32EndMagic = DBGFOSIDMESG_MAGIC; return VINF_SUCCESS; } const DBGFOSREG g_DBGDiggerDarwin = { /* .u32Magic = */ DBGFOSREG_MAGIC, /* .fFlags = */ 0, /* .cbData = */ sizeof(DBGDIGGERDARWIN), /* .szName = */ "Darwin", /* .pfnConstruct = */ dbgDiggerDarwinConstruct, /* .pfnDestruct = */ dbgDiggerDarwinDestruct, /* .pfnProbe = */ dbgDiggerDarwinProbe, /* .pfnInit = */ dbgDiggerDarwinInit, /* .pfnRefresh = */ dbgDiggerDarwinRefresh, /* .pfnTerm = */ dbgDiggerDarwinTerm, /* .pfnQueryVersion = */ dbgDiggerDarwinQueryVersion, /* .pfnQueryInterface = */ dbgDiggerDarwinQueryInterface, /* .pfnStackUnwindAssist = */ dbgDiggerDarwinStackUnwindAssist, /* .u32EndMagic = */ DBGFOSREG_MAGIC };