| /* -*- mode: C++; c-basic-offset: 4; tab-width: 4 vi:set tabstop=4 expandtab: -*/ |
| //===-- DwarfParser.hpp -----------------------------------------*- C++ -*-===// |
| // |
| // The LLVM Compiler Infrastructure |
| // |
| // This file is distributed under the University of Illinois Open Source |
| // License. See LICENSE.TXT for details. |
| // |
| //===----------------------------------------------------------------------===// |
| |
| // |
| // processor specific parsing of dwarf unwind instructions |
| // |
| |
| #ifndef __DWARF_PARSER_HPP__ |
| #define __DWARF_PARSER_HPP__ |
| |
| #include <stdint.h> |
| #include <stdio.h> |
| #include <stdlib.h> |
| |
| #include <vector> |
| |
| #include "libunwind.h" |
| #include "dwarf2.h" |
| |
| #include "AddressSpace.hpp" |
| #include "RemoteUnwindProfile.h" |
| |
| namespace lldb_private { |
| |
| |
| /// |
| /// CFI_Parser does basic parsing of a CFI (Call Frame Information) records. |
| /// See Dwarf Spec for details: |
| /// http://www.linux-foundation.org/spec/booksets/LSB-Core-generic/LSB-Core-generic/ehframechpt.html |
| /// |
| template <typename A> |
| class CFI_Parser |
| { |
| public: |
| typedef typename A::pint_t pint_t; |
| |
| /// |
| /// Information encoded in a CIE (Common Information Entry) |
| /// |
| struct CIE_Info { |
| pint_t cieStart; |
| pint_t cieLength; |
| pint_t cieInstructions; |
| uint8_t pointerEncoding; |
| uint8_t lsdaEncoding; |
| uint8_t personalityEncoding; |
| uint8_t personalityOffsetInCIE; |
| pint_t personality; |
| int codeAlignFactor; |
| int dataAlignFactor; |
| bool isSignalFrame; |
| bool fdesHaveAugmentationData; |
| }; |
| |
| /// |
| /// Information about an FDE (Frame Description Entry) |
| /// |
| struct FDE_Info { |
| pint_t fdeStart; |
| pint_t fdeLength; |
| pint_t fdeInstructions; |
| pint_t pcStart; |
| pint_t pcEnd; |
| pint_t lsda; |
| }; |
| |
| /// |
| /// Used by linker when parsing __eh_frame section |
| /// |
| struct FDE_Reference { |
| pint_t address; |
| uint32_t offsetInFDE; |
| uint8_t encodingOfAddress; |
| }; |
| struct FDE_Atom_Info { |
| pint_t fdeAddress; |
| FDE_Reference function; |
| FDE_Reference cie; |
| FDE_Reference lsda; |
| }; |
| struct CIE_Atom_Info { |
| pint_t cieAddress; |
| FDE_Reference personality; |
| }; |
| |
| |
| /// |
| /// Information about a frame layout and registers saved determined |
| /// by "running" the dwarf FDE "instructions" |
| /// |
| enum { kMaxRegisterNumber = 120 }; |
| enum RegisterSavedWhere { kRegisterUnused, kRegisterInCFA, kRegisterOffsetFromCFA, |
| kRegisterInRegister, kRegisterAtExpression, kRegisterIsExpression } ; |
| struct RegisterLocation { |
| RegisterSavedWhere location; |
| int64_t value; |
| }; |
| struct PrologInfo { |
| uint32_t cfaRegister; |
| int32_t cfaRegisterOffset; // CFA = (cfaRegister)+cfaRegisterOffset |
| int64_t cfaExpression; // CFA = expression |
| bool registersInOtherRegisters; |
| bool registerSavedMoreThanOnce; |
| bool cfaOffsetWasNegative; |
| uint32_t spExtraArgSize; |
| uint32_t codeOffsetAtStackDecrement; |
| |
| RegisterLocation savedRegisters[kMaxRegisterNumber]; // from where to restore registers |
| }; |
| |
| struct PrologInfoStackEntry { |
| PrologInfoStackEntry(PrologInfoStackEntry* n, const PrologInfo& i) |
| : next(n), info(i) {} |
| PrologInfoStackEntry* next; |
| PrologInfo info; |
| }; |
| |
| static bool findFDE(A& addressSpace, pint_t pc, pint_t ehSectionStart, uint32_t sectionLength, pint_t fdeHint, FDE_Info* fdeInfo, CIE_Info* cieInfo); |
| |
| #if defined (SUPPORT_REMOTE_UNWINDING) |
| static bool functionFuncBoundsViaFDE(A& addressSpace, pint_t ehSectionStart, uint32_t sectionLength, std::vector<FuncBounds> &funcbounds); |
| #endif |
| |
| static const char* decodeFDE(A& addressSpace, pint_t fdeStart, FDE_Info* fdeInfo, CIE_Info* cieInfo); |
| static bool parseFDEInstructions(A& addressSpace, const FDE_Info& fdeInfo, const CIE_Info& cieInfo, pint_t upToPC, PrologInfo* results); |
| static const char* getCFIs(A& addressSpace, pint_t ehSectionStart, uint32_t sectionLength, |
| std::vector<FDE_Atom_Info>& fdes, std::vector<CIE_Atom_Info>& cies); |
| static uint32_t getCFICount(A& addressSpace, pint_t ehSectionStart, uint32_t sectionLength); |
| |
| static const char* parseCIE(A& addressSpace, pint_t cie, CIE_Info* cieInfo); |
| |
| private: |
| static bool parseInstructions(A& addressSpace, pint_t instructions, pint_t instructionsEnd, const CIE_Info& cieInfo, |
| pint_t pcoffset, PrologInfoStackEntry*& rememberStack, PrologInfo* results); |
| |
| }; |
| |
| |
| /// |
| /// Parse a FDE into a CIE_Info and an FDE_Info |
| /// |
| template <typename A> |
| const char* CFI_Parser<A>::decodeFDE(A& addressSpace, pint_t fdeStart, FDE_Info* fdeInfo, CIE_Info* cieInfo) |
| { |
| pint_t p = fdeStart; |
| uint64_t cfiLength = addressSpace.get32(p); |
| p += 4; |
| if ( cfiLength == 0xffffffff ) { |
| // 0xffffffff means length is really next 8 bytes |
| cfiLength = addressSpace.get64(p); |
| p += 8; |
| } |
| if ( cfiLength == 0 ) |
| return "FDE has zero length"; // end marker |
| uint32_t ciePointer = addressSpace.get32(p); |
| if ( ciePointer == 0 ) |
| return "FDE is really a CIE"; // this is a CIE not an FDE |
| pint_t nextCFI = p + cfiLength; |
| pint_t cieStart = p-ciePointer; |
| const char* err = parseCIE(addressSpace, cieStart, cieInfo); |
| if (err != NULL) |
| return err; |
| p += 4; |
| // parse pc begin and range |
| pint_t pcStart = addressSpace.getEncodedP(p, nextCFI, cieInfo->pointerEncoding); |
| pint_t pcRange = addressSpace.getEncodedP(p, nextCFI, cieInfo->pointerEncoding & 0x0F); |
| // parse rest of info |
| fdeInfo->lsda = 0; |
| // check for augmentation length |
| if ( cieInfo->fdesHaveAugmentationData ) { |
| uintptr_t augLen = addressSpace.getULEB128(p, nextCFI); |
| pint_t endOfAug = p + augLen; |
| if ( cieInfo->lsdaEncoding != 0 ) { |
| // peek at value (without indirection). Zero means no lsda |
| pint_t lsdaStart = p; |
| if ( addressSpace.getEncodedP(p, nextCFI, cieInfo->lsdaEncoding & 0x0F) != 0 ) { |
| // reset pointer and re-parse lsda address |
| p = lsdaStart; |
| fdeInfo->lsda = addressSpace.getEncodedP(p, nextCFI, cieInfo->lsdaEncoding); |
| } |
| } |
| p = endOfAug; |
| } |
| fdeInfo->fdeStart = fdeStart; |
| fdeInfo->fdeLength = nextCFI - fdeStart; |
| fdeInfo->fdeInstructions = p; |
| fdeInfo->pcStart = pcStart; |
| fdeInfo->pcEnd = pcStart+pcRange; |
| return NULL; // success |
| } |
| |
| |
| /// |
| /// Scan an eh_frame section to find an FDE for a pc |
| /// |
| template <typename A> |
| bool CFI_Parser<A>::findFDE(A& addressSpace, pint_t pc, pint_t ehSectionStart, uint32_t sectionLength, pint_t fdeHint, FDE_Info* fdeInfo, CIE_Info* cieInfo) |
| { |
| //fprintf(stderr, "findFDE(0x%llX)\n", (long long)pc); |
| pint_t p = (fdeHint != 0) ? fdeHint : ehSectionStart; |
| const pint_t ehSectionEnd = p + sectionLength; |
| while ( p < ehSectionEnd ) { |
| pint_t currentCFI = p; |
| //fprintf(stderr, "findFDE() CFI at 0x%llX\n", (long long)p); |
| uint64_t cfiLength = addressSpace.get32(p); |
| p += 4; |
| if ( cfiLength == 0xffffffff ) { |
| // 0xffffffff means length is really next 8 bytes |
| cfiLength = addressSpace.get64(p); |
| p += 8; |
| } |
| if ( cfiLength == 0 ) |
| return false; // end marker |
| uint32_t id = addressSpace.get32(p); |
| if ( id == 0 ) { |
| // skip over CIEs |
| p += cfiLength; |
| } |
| else { |
| // process FDE to see if it covers pc |
| pint_t nextCFI = p + cfiLength; |
| uint32_t ciePointer = addressSpace.get32(p); |
| pint_t cieStart = p-ciePointer; |
| // validate pointer to CIE is within section |
| if ( (ehSectionStart <= cieStart) && (cieStart < ehSectionEnd) ) { |
| if ( parseCIE(addressSpace, cieStart, cieInfo) == NULL ) { |
| p += 4; |
| // parse pc begin and range |
| pint_t pcStart = addressSpace.getEncodedP(p, nextCFI, cieInfo->pointerEncoding); |
| pint_t pcRange = addressSpace.getEncodedP(p, nextCFI, cieInfo->pointerEncoding & 0x0F); |
| //fprintf(stderr, "FDE with pcRange [0x%08llX, 0x%08llX)\n",(uint64_t)pcStart, (uint64_t)(pcStart+pcRange)); |
| // test if pc is within the function this FDE covers |
| if ( (pcStart < pc) && (pc <= pcStart+pcRange) ) { |
| // parse rest of info |
| fdeInfo->lsda = 0; |
| // check for augmentation length |
| if ( cieInfo->fdesHaveAugmentationData ) { |
| uintptr_t augLen = addressSpace.getULEB128(p, nextCFI); |
| pint_t endOfAug = p + augLen; |
| if ( cieInfo->lsdaEncoding != 0 ) { |
| // peek at value (without indirection). Zero means no lsda |
| pint_t lsdaStart = p; |
| if ( addressSpace.getEncodedP(p, nextCFI, cieInfo->lsdaEncoding & 0x0F) != 0 ) { |
| // reset pointer and re-parse lsda address |
| p = lsdaStart; |
| fdeInfo->lsda = addressSpace.getEncodedP(p, nextCFI, cieInfo->lsdaEncoding); |
| } |
| } |
| p = endOfAug; |
| } |
| fdeInfo->fdeStart = currentCFI; |
| fdeInfo->fdeLength = nextCFI - currentCFI; |
| fdeInfo->fdeInstructions = p; |
| fdeInfo->pcStart = pcStart; |
| fdeInfo->pcEnd = pcStart+pcRange; |
| //fprintf(stderr, "findFDE(pc=0x%llX) found with pcRange [0x%08llX, 0x%08llX)\n",(uint64_t)pc, (uint64_t)pcStart, (uint64_t)(pcStart+pcRange)); |
| return true; |
| } |
| else { |
| //fprintf(stderr, "findFDE(pc=0x%llX) not found with pcRange [0x%08llX, 0x%08llX)\n",(uint64_t)pc, (uint64_t)pcStart, (uint64_t)(pcStart+pcRange)); |
| // pc is not in begin/range, skip this FDE |
| } |
| } |
| else { |
| // malformed CIE, now augmentation describing pc range encoding |
| //fprintf(stderr, "malformed CIE\n"); |
| } |
| } |
| else { |
| // malformed FDE. CIE is bad |
| //fprintf(stderr, "malformed FDE, cieStart=0x%llX, ehSectionStart=0x%llX, ehSectionEnd=0x%llX\n", |
| // (uint64_t)cieStart, (uint64_t)ehSectionStart, (uint64_t)ehSectionEnd); |
| } |
| p = nextCFI; |
| } |
| } |
| //fprintf(stderr, "findFDE(pc=0x%llX) not found\n",(uint64_t)pc); |
| return false; |
| } |
| |
| #if defined (SUPPORT_REMOTE_UNWINDING) |
| /// Scan an eh_frame section to find all the function start addresses |
| /// This is only made for working with libunwind-remote. It copies |
| /// the eh_frame section into local memory and steps through it quickly |
| /// to find the start addresses of the CFIs. |
| /// |
| template <typename A> |
| bool CFI_Parser<A>::functionFuncBoundsViaFDE(A& addressSpace, pint_t ehSectionStart, |
| uint32_t sectionLength, std::vector<FuncBounds> &funcbounds) |
| { |
| //fprintf(stderr, "functionFuncBoundsViaFDE(0x%llX)\n", (long long)pc); |
| pint_t p = ehSectionStart; |
| const pint_t ehSectionEnd = p + sectionLength; |
| pint_t lastCieSeen = (pint_t) -1; |
| CIE_Info cieInfo; |
| while ( p < ehSectionEnd ) { |
| //fprintf(stderr, "functionFuncBoundsViaFDE() CFI at 0x%llX\n", (long long)p); |
| uint64_t cfiLength = addressSpace.get32(p); |
| p += 4; |
| if ( cfiLength == 0xffffffff ) { |
| // 0xffffffff means length is really next 8 bytes |
| cfiLength = addressSpace.get64(p); |
| p += 8; |
| } |
| if ( cfiLength == 0 ) |
| return false; // end marker |
| uint32_t id = addressSpace.get32(p); |
| if ( id == 0 ) { |
| // skip over CIEs |
| p += cfiLength; |
| } |
| else { |
| // process FDE to see if it covers pc |
| pint_t nextCFI = p + cfiLength; |
| uint32_t ciePointer = addressSpace.get32(p); |
| pint_t cieStart = p-ciePointer; |
| // validate pointer to CIE is within section |
| if ( (ehSectionStart <= cieStart) && (cieStart < ehSectionEnd) ) { |
| const char *errmsg; |
| // don't re-parse the cie if this fde is pointing to one we already parsed |
| if (cieStart == lastCieSeen) { |
| errmsg = NULL; |
| } |
| else { |
| errmsg = parseCIE(addressSpace, cieStart, &cieInfo); |
| if (errmsg == NULL) |
| lastCieSeen = cieStart; |
| } |
| if ( errmsg == NULL ) { |
| p += 4; |
| // parse pc begin and range |
| pint_t pcStart = addressSpace.getEncodedP(p, nextCFI, cieInfo.pointerEncoding); |
| pint_t pcRange = addressSpace.getEncodedP(p, nextCFI, cieInfo.pointerEncoding & 0x0F); |
| //fprintf(stderr, "FDE with pcRange [0x%08llX, 0x%08llX)\n",(uint64_t)pcStart, (uint64_t)(pcStart+pcRange)); |
| funcbounds.push_back(FuncBounds(pcStart, pcStart + pcRange)); |
| } |
| else { |
| // malformed CIE, now augmentation describing pc range encoding |
| //fprintf(stderr, "malformed CIE\n"); |
| return false; |
| } |
| } |
| else { |
| // malformed FDE. CIE is bad |
| //fprintf(stderr, "malformed FDE, cieStart=0x%llX, ehSectionStart=0x%llX, ehSectionEnd=0x%llX\n", |
| // (uint64_t)cieStart, (uint64_t)ehSectionStart, (uint64_t)ehSectionEnd); |
| return false; |
| } |
| p = nextCFI; |
| } |
| } |
| return true; |
| } |
| #endif // SUPPORT_REMOTE_UNWINDING |
| |
| |
| |
| /// |
| /// Extract info from a CIE |
| /// |
| template <typename A> |
| const char* CFI_Parser<A>::parseCIE(A& addressSpace, pint_t cie, CIE_Info* cieInfo) |
| { |
| //fprintf(stderr, "parseCIE(0x%llX)\n", (long long)cie); |
| cieInfo->pointerEncoding = 0; |
| cieInfo->lsdaEncoding = 0; |
| cieInfo->personalityEncoding = 0; |
| cieInfo->personalityOffsetInCIE = 0; |
| cieInfo->personality = 0; |
| cieInfo->codeAlignFactor = 0; |
| cieInfo->dataAlignFactor = 0; |
| cieInfo->isSignalFrame = false; |
| cieInfo->fdesHaveAugmentationData = false; |
| cieInfo->cieStart = cie; |
| pint_t p = cie; |
| uint64_t cieLength = addressSpace.get32(p); |
| p += 4; |
| pint_t cieContentEnd = p + cieLength; |
| if ( cieLength == 0xffffffff ) { |
| // 0xffffffff means length is really next 8 bytes |
| cieLength = addressSpace.get64(p); |
| p += 8; |
| cieContentEnd = p + cieLength; |
| } |
| if ( cieLength == 0 ) |
| return false; |
| // CIE ID is always 0 |
| if ( addressSpace.get32(p) != 0 ) |
| return "CIE ID is not zero"; |
| p += 4; |
| // Version is always 1 or 3 |
| uint8_t version = addressSpace.get8(p); |
| if ( (version != 1) && (version != 3) ) |
| return "CIE version is not 1 or 3"; |
| ++p; |
| // save start of augmentation string and find end |
| pint_t strStart = p; |
| while ( addressSpace.get8(p) != 0 ) |
| ++p; |
| ++p; |
| // parse code aligment factor |
| cieInfo->codeAlignFactor = addressSpace.getULEB128(p, cieContentEnd); |
| // parse data alignment factor |
| cieInfo->dataAlignFactor = addressSpace.getSLEB128(p, cieContentEnd); |
| // parse return address register |
| addressSpace.getULEB128(p, cieContentEnd); |
| // parse augmentation data based on augmentation string |
| const char* result = NULL; |
| if ( addressSpace.get8(strStart) == 'z' ) { |
| // parse augmentation data length |
| addressSpace.getULEB128(p, cieContentEnd); |
| for (pint_t s=strStart; addressSpace.get8(s) != '\0'; ++s) { |
| switch ( addressSpace.get8(s) ) { |
| case 'z': |
| cieInfo->fdesHaveAugmentationData = true; |
| break; |
| case 'P': |
| cieInfo->personalityEncoding = addressSpace.get8(p); |
| ++p; |
| cieInfo->personalityOffsetInCIE = p-cie; |
| cieInfo->personality = addressSpace.getEncodedP(p, cieContentEnd, cieInfo->personalityEncoding); |
| break; |
| case 'L': |
| cieInfo->lsdaEncoding = addressSpace.get8(p); |
| ++p; |
| break; |
| case 'R': |
| cieInfo->pointerEncoding = addressSpace.get8(p); |
| ++p; |
| break; |
| case 'S': |
| cieInfo->isSignalFrame = true; |
| break; |
| default: |
| // ignore unknown letters |
| break; |
| } |
| } |
| } |
| cieInfo->cieLength = cieContentEnd - cieInfo->cieStart; |
| cieInfo->cieInstructions = p; |
| return result; |
| } |
| |
| |
| template <typename A> |
| uint32_t CFI_Parser<A>::getCFICount(A& addressSpace, pint_t ehSectionStart, uint32_t sectionLength) |
| { |
| uint32_t count = 0; |
| const pint_t ehSectionEnd = ehSectionStart + sectionLength; |
| for (pint_t p=ehSectionStart; p < ehSectionEnd; ) { |
| uint64_t cfiLength = addressSpace.get32(p); |
| p += 4; |
| if ( cfiLength == 0xffffffff ) { |
| // 0xffffffff means length is really next 8 bytes |
| cfiLength = addressSpace.get64(p); |
| p += 8; |
| } |
| if ( cfiLength == 0 ) |
| return count; // end marker |
| ++count; |
| p += cfiLength; |
| } |
| return count; |
| } |
| |
| |
| |
| template <typename A> |
| const char* CFI_Parser<A>::getCFIs(A& addressSpace, pint_t ehSectionStart, uint32_t sectionLength, |
| std::vector<FDE_Atom_Info>& fdes, std::vector<CIE_Atom_Info>& cies) |
| { |
| const pint_t ehSectionEnd = ehSectionStart + sectionLength; |
| for (pint_t p=ehSectionStart; p < ehSectionEnd; ) { |
| pint_t currentCFI = p; |
| uint64_t cfiLength = addressSpace.get32(p); |
| p += 4; |
| if ( cfiLength == 0xffffffff ) { |
| // 0xffffffff means length is really next 8 bytes |
| cfiLength = addressSpace.get64(p); |
| p += 8; |
| } |
| if ( cfiLength == 0 ) |
| return NULL; // end marker |
| uint32_t id = addressSpace.get32(p); |
| if ( id == 0 ) { |
| // is CIE |
| CIE_Info cieInfo; |
| const char* err = parseCIE(addressSpace, currentCFI, &cieInfo); |
| if ( err != NULL ) |
| return err; |
| CIE_Atom_Info entry; |
| entry.cieAddress = currentCFI; |
| entry.personality.address = cieInfo.personality; |
| entry.personality.offsetInFDE = cieInfo.personalityOffsetInCIE; |
| entry.personality.encodingOfAddress = cieInfo.personalityEncoding; |
| cies.push_back(entry); |
| p += cfiLength; |
| } |
| else { |
| // is FDE |
| FDE_Atom_Info entry; |
| entry.fdeAddress = currentCFI; |
| entry.function.address = 0; |
| entry.cie.address = 0; |
| entry.lsda.address = 0; |
| pint_t nextCFI = p + cfiLength; |
| uint32_t ciePointer = addressSpace.get32(p); |
| pint_t cieStart = p-ciePointer; |
| // validate pointer to CIE is within section |
| if ( (cieStart < ehSectionStart) || (cieStart > ehSectionEnd) ) |
| return "FDE points to CIE outside __eh_frame section"; |
| CIE_Info cieInfo; |
| const char* err = parseCIE(addressSpace, cieStart, &cieInfo); |
| if ( err != NULL ) |
| return err; |
| entry.cie.address = cieStart; |
| entry.cie.offsetInFDE = p-currentCFI; |
| entry.cie.encodingOfAddress = DW_EH_PE_sdata4 | DW_EH_PE_pcrel; |
| p += 4; |
| // parse pc begin and range |
| pint_t offsetOfFunctionAddress = p-currentCFI; |
| pint_t pcStart = addressSpace.getEncodedP(p, nextCFI, cieInfo.pointerEncoding); |
| pint_t pcRange = addressSpace.getEncodedP(p, nextCFI, cieInfo.pointerEncoding & 0x0F); |
| //fprintf(stderr, "FDE with pcRange [0x%08llX, 0x%08llX)\n",(uint64_t)pcStart, (uint64_t)(pcStart+pcRange)); |
| // test if pc is within the function this FDE covers |
| entry.function.address = pcStart; |
| entry.function.offsetInFDE = offsetOfFunctionAddress; |
| entry.function.encodingOfAddress = cieInfo.pointerEncoding; |
| // skip over augmentation length |
| if ( cieInfo.fdesHaveAugmentationData ) { |
| uintptr_t augLen = addressSpace.getULEB128(p, nextCFI); |
| pint_t endOfAug = p + augLen; |
| if ( (cieInfo.lsdaEncoding != 0) && (addressSpace.getP(p) != 0) ) { |
| pint_t offsetOfLSDAAddress = p-currentCFI; |
| entry.lsda.address = addressSpace.getEncodedP(p, nextCFI, cieInfo.lsdaEncoding); |
| entry.lsda.offsetInFDE = offsetOfLSDAAddress; |
| entry.lsda.encodingOfAddress = cieInfo.lsdaEncoding; |
| } |
| p = endOfAug; |
| } |
| fdes.push_back(entry); |
| p = nextCFI; |
| } |
| } |
| return NULL; // success |
| } |
| |
| |
| |
| /// |
| /// "run" the dwarf instructions and create the abstact PrologInfo for an FDE |
| /// |
| template <typename A> |
| bool CFI_Parser<A>::parseFDEInstructions(A& addressSpace, const FDE_Info& fdeInfo, const CIE_Info& cieInfo, pint_t upToPC, PrologInfo* results) |
| { |
| // clear results |
| bzero(results, sizeof(PrologInfo)); |
| PrologInfoStackEntry* rememberStack = NULL; |
| |
| // parse CIE then FDE instructions |
| return parseInstructions(addressSpace, cieInfo.cieInstructions, cieInfo.cieStart+cieInfo.cieLength, |
| cieInfo, (pint_t)(-1), rememberStack, results) |
| && parseInstructions(addressSpace, fdeInfo.fdeInstructions, fdeInfo.fdeStart+fdeInfo.fdeLength, |
| cieInfo, upToPC-fdeInfo.pcStart, rememberStack, results); |
| } |
| |
| |
| /// |
| /// "run" the dwarf instructions |
| /// |
| template <typename A> |
| bool CFI_Parser<A>::parseInstructions(A& addressSpace, pint_t instructions, pint_t instructionsEnd, const CIE_Info& cieInfo, |
| pint_t pcoffset, PrologInfoStackEntry*& rememberStack, PrologInfo* results) |
| { |
| const bool logDwarf = false; |
| pint_t p = instructions; |
| uint32_t codeOffset = 0; |
| PrologInfo initialState = *results; |
| |
| // see Dwarf Spec, section 6.4.2 for details on unwind opcodes |
| while ( (p < instructionsEnd) && (codeOffset < pcoffset) ) { |
| uint64_t reg; |
| uint64_t reg2; |
| int64_t offset; |
| uint64_t length; |
| uint8_t opcode = addressSpace.get8(p); |
| uint8_t operand; |
| PrologInfoStackEntry* entry; |
| ++p; |
| switch (opcode) { |
| case DW_CFA_nop: |
| if ( logDwarf ) fprintf(stderr, "DW_CFA_nop\n"); |
| break; |
| case DW_CFA_set_loc: |
| codeOffset = addressSpace.getEncodedP(p, instructionsEnd, cieInfo.pointerEncoding); |
| if ( logDwarf ) fprintf(stderr, "DW_CFA_set_loc\n"); |
| break; |
| case DW_CFA_advance_loc1: |
| codeOffset += (addressSpace.get8(p) * cieInfo.codeAlignFactor); |
| p += 1; |
| if ( logDwarf ) fprintf(stderr, "DW_CFA_advance_loc1: new offset=%u\n", codeOffset); |
| break; |
| case DW_CFA_advance_loc2: |
| codeOffset += (addressSpace.get16(p) * cieInfo.codeAlignFactor); |
| p += 2; |
| if ( logDwarf ) fprintf(stderr, "DW_CFA_advance_loc2: new offset=%u\n", codeOffset); |
| break; |
| case DW_CFA_advance_loc4: |
| codeOffset += (addressSpace.get32(p) * cieInfo.codeAlignFactor); |
| p += 4; |
| if ( logDwarf ) fprintf(stderr, "DW_CFA_advance_loc4: new offset=%u\n", codeOffset); |
| break; |
| case DW_CFA_offset_extended: |
| reg = addressSpace.getULEB128(p, instructionsEnd); |
| offset = addressSpace.getULEB128(p, instructionsEnd) * cieInfo.dataAlignFactor; |
| if ( reg > kMaxRegisterNumber ) { |
| fprintf(stderr, "malformed DW_CFA_offset_extended dwarf unwind, reg too big\n"); |
| return false; |
| } |
| if ( results->savedRegisters[reg].location != kRegisterUnused ) |
| results->registerSavedMoreThanOnce = true; |
| results->savedRegisters[reg].location = kRegisterInCFA; |
| results->savedRegisters[reg].value = offset; |
| if ( logDwarf ) fprintf(stderr, "DW_CFA_offset_extended(reg=%lld, offset=%lld)\n", reg, offset); |
| break; |
| case DW_CFA_restore_extended: |
| reg = addressSpace.getULEB128(p, instructionsEnd);; |
| if ( reg > kMaxRegisterNumber ) { |
| fprintf(stderr, "malformed DW_CFA_restore_extended dwarf unwind, reg too big\n"); |
| return false; |
| } |
| results->savedRegisters[reg] = initialState.savedRegisters[reg]; |
| if ( logDwarf ) fprintf(stderr, "DW_CFA_restore_extended(reg=%lld)\n", reg); |
| break; |
| case DW_CFA_undefined: |
| reg = addressSpace.getULEB128(p, instructionsEnd); |
| if ( reg > kMaxRegisterNumber ) { |
| fprintf(stderr, "malformed DW_CFA_undefined dwarf unwind, reg too big\n"); |
| return false; |
| } |
| results->savedRegisters[reg].location = kRegisterUnused; |
| if ( logDwarf ) fprintf(stderr, "DW_CFA_undefined(reg=%lld)\n", reg); |
| break; |
| case DW_CFA_same_value: |
| reg = addressSpace.getULEB128(p, instructionsEnd); |
| if ( reg > kMaxRegisterNumber ) { |
| fprintf(stderr, "malformed DW_CFA_same_value dwarf unwind, reg too big\n"); |
| return false; |
| } |
| if ( logDwarf ) fprintf(stderr, "DW_CFA_same_value(reg=%lld)\n", reg); |
| break; |
| case DW_CFA_register: |
| reg = addressSpace.getULEB128(p, instructionsEnd); |
| reg2 = addressSpace.getULEB128(p, instructionsEnd); |
| if ( reg > kMaxRegisterNumber ) { |
| fprintf(stderr, "malformed DW_CFA_register dwarf unwind, reg too big\n"); |
| return false; |
| } |
| if ( reg2 > kMaxRegisterNumber ) { |
| fprintf(stderr, "malformed DW_CFA_register dwarf unwind, reg2 too big\n"); |
| return false; |
| } |
| results->savedRegisters[reg].location = kRegisterInRegister; |
| results->savedRegisters[reg].value = reg2; |
| results->registersInOtherRegisters = true; |
| if ( logDwarf ) fprintf(stderr, "DW_CFA_register(reg=%lld, reg2=%lld)\n", reg, reg2); |
| break; |
| case DW_CFA_remember_state: |
| // avoid operator new, because that would be an upward dependency |
| entry = (PrologInfoStackEntry*)malloc(sizeof(PrologInfoStackEntry)); |
| if ( entry != NULL ) { |
| entry->next = rememberStack; |
| entry->info = *results; |
| rememberStack = entry; |
| } |
| else { |
| return false; |
| } |
| if ( logDwarf ) fprintf(stderr, "DW_CFA_remember_state\n"); |
| break; |
| case DW_CFA_restore_state: |
| if ( rememberStack != NULL ) { |
| PrologInfoStackEntry* top = rememberStack; |
| *results = top->info; |
| rememberStack = top->next; |
| free((char*)top); |
| } |
| else { |
| return false; |
| } |
| if ( logDwarf ) fprintf(stderr, "DW_CFA_restore_state\n"); |
| break; |
| case DW_CFA_def_cfa: |
| reg = addressSpace.getULEB128(p, instructionsEnd); |
| offset = addressSpace.getULEB128(p, instructionsEnd); |
| if ( reg > kMaxRegisterNumber ) { |
| fprintf(stderr, "malformed DW_CFA_def_cfa dwarf unwind, reg too big\n"); |
| return false; |
| } |
| results->cfaRegister = reg; |
| results->cfaRegisterOffset = offset; |
| if ( offset > 0x80000000 ) |
| results->cfaOffsetWasNegative = true; |
| if ( logDwarf ) fprintf(stderr, "DW_CFA_def_cfa(reg=%lld, offset=%lld)\n", reg, offset); |
| break; |
| case DW_CFA_def_cfa_register: |
| reg = addressSpace.getULEB128(p, instructionsEnd); |
| if ( reg > kMaxRegisterNumber ) { |
| fprintf(stderr, "malformed DW_CFA_def_cfa_register dwarf unwind, reg too big\n"); |
| return false; |
| } |
| results->cfaRegister = reg; |
| if ( logDwarf ) fprintf(stderr, "DW_CFA_def_cfa_register(%lld)\n", reg); |
| break; |
| case DW_CFA_def_cfa_offset: |
| results->cfaRegisterOffset = addressSpace.getULEB128(p, instructionsEnd); |
| results->codeOffsetAtStackDecrement = codeOffset; |
| if ( logDwarf ) fprintf(stderr, "DW_CFA_def_cfa_offset(%d)\n", results->cfaRegisterOffset); |
| break; |
| case DW_CFA_def_cfa_expression: |
| results->cfaRegister = 0; |
| results->cfaExpression = p; |
| length = addressSpace.getULEB128(p, instructionsEnd); |
| p += length; |
| if ( logDwarf ) fprintf(stderr, "DW_CFA_def_cfa_expression(expression=0x%llX, length=%llu)\n", |
| results->cfaExpression, length); |
| break; |
| case DW_CFA_expression: |
| reg = addressSpace.getULEB128(p, instructionsEnd); |
| if ( reg > kMaxRegisterNumber ) { |
| fprintf(stderr, "malformed DW_CFA_expression dwarf unwind, reg too big\n"); |
| return false; |
| } |
| results->savedRegisters[reg].location = kRegisterAtExpression; |
| results->savedRegisters[reg].value = p; |
| length = addressSpace.getULEB128(p, instructionsEnd); |
| p += length; |
| if ( logDwarf ) fprintf(stderr, "DW_CFA_expression(reg=%lld, expression=0x%llX, length=%llu)\n", |
| reg, results->savedRegisters[reg].value, length); |
| break; |
| case DW_CFA_offset_extended_sf: |
| reg = addressSpace.getULEB128(p, instructionsEnd); |
| if ( reg > kMaxRegisterNumber ) { |
| fprintf(stderr, "malformed DW_CFA_offset_extended_sf dwarf unwind, reg too big\n"); |
| return false; |
| } |
| offset = addressSpace.getSLEB128(p, instructionsEnd) * cieInfo.dataAlignFactor; |
| if ( results->savedRegisters[reg].location != kRegisterUnused ) |
| results->registerSavedMoreThanOnce = true; |
| results->savedRegisters[reg].location = kRegisterInCFA; |
| results->savedRegisters[reg].value = offset; |
| if ( logDwarf ) fprintf(stderr, "DW_CFA_offset_extended_sf(reg=%lld, offset=%lld)\n", reg, offset); |
| break; |
| case DW_CFA_def_cfa_sf: |
| reg = addressSpace.getULEB128(p, instructionsEnd); |
| offset = addressSpace.getSLEB128(p, instructionsEnd) * cieInfo.dataAlignFactor; |
| if ( reg > kMaxRegisterNumber ) { |
| fprintf(stderr, "malformed DW_CFA_def_cfa_sf dwarf unwind, reg too big\n"); |
| return false; |
| } |
| results->cfaRegister = reg; |
| results->cfaRegisterOffset = offset; |
| if ( logDwarf ) fprintf(stderr, "DW_CFA_def_cfa_sf(reg=%lld, offset=%lld)\n", reg, offset); |
| break; |
| case DW_CFA_def_cfa_offset_sf: |
| results->cfaRegisterOffset = addressSpace.getSLEB128(p, instructionsEnd) * cieInfo.dataAlignFactor; |
| results->codeOffsetAtStackDecrement = codeOffset; |
| if ( logDwarf ) fprintf(stderr, "DW_CFA_def_cfa_offset_sf(%d)\n", results->cfaRegisterOffset); |
| break; |
| case DW_CFA_val_offset: |
| reg = addressSpace.getULEB128(p, instructionsEnd); |
| offset = addressSpace.getULEB128(p, instructionsEnd) * cieInfo.dataAlignFactor; |
| results->savedRegisters[reg].location = kRegisterOffsetFromCFA; |
| results->savedRegisters[reg].value = offset; |
| if ( logDwarf ) fprintf(stderr, "DW_CFA_val_offset(reg=%lld, offset=%lld\n", reg, offset); |
| break; |
| case DW_CFA_val_offset_sf: |
| reg = addressSpace.getULEB128(p, instructionsEnd); |
| if ( reg > kMaxRegisterNumber ) { |
| fprintf(stderr, "malformed DW_CFA_val_offset_sf dwarf unwind, reg too big\n"); |
| return false; |
| } |
| offset = addressSpace.getSLEB128(p, instructionsEnd) * cieInfo.dataAlignFactor; |
| results->savedRegisters[reg].location = kRegisterOffsetFromCFA; |
| results->savedRegisters[reg].value = offset; |
| if ( logDwarf ) fprintf(stderr, "DW_CFA_val_offset_sf(reg=%lld, offset=%lld\n", reg, offset); |
| break; |
| case DW_CFA_val_expression: |
| reg = addressSpace.getULEB128(p, instructionsEnd); |
| if ( reg > kMaxRegisterNumber ) { |
| fprintf(stderr, "malformed DW_CFA_val_expression dwarf unwind, reg too big\n"); |
| return false; |
| } |
| results->savedRegisters[reg].location = kRegisterIsExpression; |
| results->savedRegisters[reg].value = p; |
| length = addressSpace.getULEB128(p, instructionsEnd); |
| p += length; |
| if ( logDwarf ) fprintf(stderr, "DW_CFA_val_expression(reg=%lld, expression=0x%llX, length=%lld)\n", |
| reg, results->savedRegisters[reg].value, length); |
| break; |
| case DW_CFA_GNU_args_size: |
| offset = addressSpace.getULEB128(p, instructionsEnd); |
| results->spExtraArgSize = offset; |
| if ( logDwarf ) fprintf(stderr, "DW_CFA_GNU_args_size(%lld)\n", offset); |
| break; |
| case DW_CFA_GNU_negative_offset_extended: |
| reg = addressSpace.getULEB128(p, instructionsEnd); |
| if ( reg > kMaxRegisterNumber ) { |
| fprintf(stderr, "malformed DW_CFA_GNU_negative_offset_extended dwarf unwind, reg too big\n"); |
| return false; |
| } |
| offset = addressSpace.getULEB128(p, instructionsEnd) * cieInfo.dataAlignFactor; |
| if ( results->savedRegisters[reg].location != kRegisterUnused ) |
| results->registerSavedMoreThanOnce = true; |
| results->savedRegisters[reg].location = kRegisterInCFA; |
| results->savedRegisters[reg].value = -offset; |
| if ( logDwarf ) fprintf(stderr, "DW_CFA_GNU_negative_offset_extended(%lld)\n", offset); |
| break; |
| default: |
| operand = opcode & 0x3F; |
| switch ( opcode & 0xC0 ) { |
| case DW_CFA_offset: |
| reg = operand; |
| offset = addressSpace.getULEB128(p, instructionsEnd) * cieInfo.dataAlignFactor; |
| if ( results->savedRegisters[reg].location != kRegisterUnused ) |
| results->registerSavedMoreThanOnce = true; |
| results->savedRegisters[reg].location = kRegisterInCFA; |
| results->savedRegisters[reg].value = offset; |
| if ( logDwarf ) fprintf(stderr, "DW_CFA_offset(reg=%d, offset=%lld)\n", operand, offset); |
| break; |
| case DW_CFA_advance_loc: |
| codeOffset += operand * cieInfo.codeAlignFactor; |
| if ( logDwarf ) fprintf(stderr, "DW_CFA_advance_loc: new offset=%u\n", codeOffset); |
| break; |
| case DW_CFA_restore: |
| // <rdar://problem/7503075> Python crashes when handling an exception thrown by an obj-c object |
| // libffi uses DW_CFA_restore in the middle of some custom dward, so it is not a good epilog flag |
| //return true; // gcc-4.5 starts the epilog with this |
| reg = operand; |
| results->savedRegisters[reg] = initialState.savedRegisters[reg]; |
| if ( logDwarf ) fprintf(stderr, "DW_CFA_restore(reg=%lld)\n", reg); |
| break; |
| default: |
| if ( logDwarf ) fprintf(stderr, "unknown CFA opcode 0x%02X\n", opcode); |
| return false; |
| } |
| } |
| } |
| |
| return true; |
| } |
| |
| |
| } // namespace lldb_private |
| |
| |
| #endif // __DWARF_PARSER_HPP__ |
| |
| |
| |
| |