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Diffstat (limited to 'lldb/source/Plugins/Process/Utility/libunwind/src/DwarfInstructions.hpp')
| -rw-r--r-- | lldb/source/Plugins/Process/Utility/libunwind/src/DwarfInstructions.hpp | 1686 |
1 files changed, 1686 insertions, 0 deletions
diff --git a/lldb/source/Plugins/Process/Utility/libunwind/src/DwarfInstructions.hpp b/lldb/source/Plugins/Process/Utility/libunwind/src/DwarfInstructions.hpp new file mode 100644 index 00000000000..589c30b50b9 --- /dev/null +++ b/lldb/source/Plugins/Process/Utility/libunwind/src/DwarfInstructions.hpp @@ -0,0 +1,1686 @@ +/* -*- mode: C++; c-basic-offset: 4; tab-width: 4 vi:set tabstop=4 expandtab: -*/ +//===-- DwarfInstructions.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_INSTRUCTIONS_HPP__ +#define __DWARF_INSTRUCTIONS_HPP__ + +#include <stdint.h> +#include <stdio.h> +#include <stdlib.h> + +#include <algorithm> +#include <vector> + +#include <libunwind.h> +#include <mach-o/compact_unwind_encoding.h> + +#include "dwarf2.h" +#include "AddressSpace.hpp" +#include "Registers.hpp" +#include "DwarfParser.hpp" +#include "InternalMacros.h" +//#include "CompactUnwinder.hpp" + +#define EXTRACT_BITS(value, mask) \ + ( (value >> __builtin_ctz(mask)) & (((1 << __builtin_popcount(mask)))-1) ) + +#define CFI_INVALID_ADDRESS ((pint_t)(-1)) + +namespace lldb_private { + +/// +/// Used by linker when parsing __eh_frame section +/// +template <typename A> +struct CFI_Reference { + typedef typename A::pint_t pint_t; + uint8_t encodingOfTargetAddress; + uint32_t offsetInCFI; + pint_t targetAddress; +}; +template <typename A> +struct CFI_Atom_Info { + typedef typename A::pint_t pint_t; + pint_t address; + uint32_t size; + bool isCIE; + union { + struct { + CFI_Reference<A> function; + CFI_Reference<A> cie; + CFI_Reference<A> lsda; + uint32_t compactUnwindInfo; + } fdeInfo; + struct { + CFI_Reference<A> personality; + } cieInfo; + } u; +}; + +typedef void (*WarnFunc)(void* ref, uint64_t funcAddr, const char* msg); + +/// +/// DwarfInstructions maps abtract dwarf unwind instructions to a particular architecture +/// +template <typename A, typename R> +class DwarfInstructions +{ +public: + typedef typename A::pint_t pint_t; + typedef typename A::sint_t sint_t; + + static const char* parseCFIs(A& addressSpace, pint_t ehSectionStart, uint32_t sectionLength, + CFI_Atom_Info<A>* infos, uint32_t infosCount, void* ref, WarnFunc warn); + + + static compact_unwind_encoding_t createCompactEncodingFromFDE(A& addressSpace, pint_t fdeStart, + pint_t* lsda, pint_t* personality, + char warningBuffer[1024]); + + static int stepWithDwarf(A& addressSpace, pint_t pc, pint_t fdeStart, R& registers); + +private: + + enum { + DW_X86_64_RET_ADDR = 16 + }; + + enum { + DW_X86_RET_ADDR = 8 + }; + + static pint_t evaluateExpression(pint_t expression, A& addressSpace, const R& registers, pint_t initialStackValue); + static pint_t getSavedRegister(A& addressSpace, const R& registers, pint_t cfa, + const typename CFI_Parser<A>::RegisterLocation& savedReg); + static double getSavedFloatRegister(A& addressSpace, const R& registers, pint_t cfa, + const typename CFI_Parser<A>::RegisterLocation& savedReg); + static v128 getSavedVectorRegister(A& addressSpace, const R& registers, pint_t cfa, + const typename CFI_Parser<A>::RegisterLocation& savedReg); + + // x86 specific variants + static int lastRestoreReg(const Registers_x86&); + static bool isReturnAddressRegister(int regNum, const Registers_x86&); + static pint_t getCFA(A& addressSpace, const typename CFI_Parser<A>::PrologInfo& prolog, const Registers_x86&); + + static uint32_t getEBPEncodedRegister(uint32_t reg, int32_t regOffsetFromBaseOffset, bool& failure); + static compact_unwind_encoding_t encodeToUseDwarf(const Registers_x86&); + static compact_unwind_encoding_t createCompactEncodingFromProlog(A& addressSpace, pint_t funcAddr, + const Registers_x86&, const typename CFI_Parser<A>::PrologInfo& prolog, + char warningBuffer[1024]); + + // x86_64 specific variants + static int lastRestoreReg(const Registers_x86_64&); + static bool isReturnAddressRegister(int regNum, const Registers_x86_64&); + static pint_t getCFA(A& addressSpace, const typename CFI_Parser<A>::PrologInfo& prolog, const Registers_x86_64&); + + static uint32_t getRBPEncodedRegister(uint32_t reg, int32_t regOffsetFromBaseOffset, bool& failure); + static compact_unwind_encoding_t encodeToUseDwarf(const Registers_x86_64&); + static compact_unwind_encoding_t createCompactEncodingFromProlog(A& addressSpace, pint_t funcAddr, + const Registers_x86_64&, const typename CFI_Parser<A>::PrologInfo& prolog, + char warningBuffer[1024]); + + // ppc specific variants + static int lastRestoreReg(const Registers_ppc&); + static bool isReturnAddressRegister(int regNum, const Registers_ppc&); + static pint_t getCFA(A& addressSpace, const typename CFI_Parser<A>::PrologInfo& prolog, const Registers_ppc&); + static compact_unwind_encoding_t encodeToUseDwarf(const Registers_ppc&); + static compact_unwind_encoding_t createCompactEncodingFromProlog(A& addressSpace, pint_t funcAddr, + const Registers_ppc&, const typename CFI_Parser<A>::PrologInfo& prolog, + char warningBuffer[1024]); +}; + + + + +template <typename A, typename R> +const char* DwarfInstructions<A,R>::parseCFIs(A& addressSpace, pint_t ehSectionStart, uint32_t sectionLength, + CFI_Atom_Info<A>* infos, uint32_t infosCount, void* ref, WarnFunc warn) +{ + typename CFI_Parser<A>::CIE_Info cieInfo; + CFI_Atom_Info<A>* entry = infos; + CFI_Atom_Info<A>* end = &infos[infosCount]; + 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 + if ( entry >= end ) + return "too little space allocated for parseCFIs"; + pint_t nextCFI = p + cfiLength; + uint32_t id = addressSpace.get32(p); + if ( id == 0 ) { + // is CIE + const char* err = CFI_Parser<A>::parseCIE(addressSpace, currentCFI, &cieInfo); + if ( err != NULL ) + return err; + entry->address = currentCFI; + entry->size = nextCFI - currentCFI; + entry->isCIE = true; + entry->u.cieInfo.personality.targetAddress = cieInfo.personality; + entry->u.cieInfo.personality.offsetInCFI = cieInfo.personalityOffsetInCIE; + entry->u.cieInfo.personality.encodingOfTargetAddress = cieInfo.personalityEncoding; + ++entry; + } + else { + // is FDE + entry->address = currentCFI; + entry->size = nextCFI - currentCFI; + entry->isCIE = false; + entry->u.fdeInfo.function.targetAddress = CFI_INVALID_ADDRESS; + entry->u.fdeInfo.cie.targetAddress = CFI_INVALID_ADDRESS; + entry->u.fdeInfo.lsda.targetAddress = CFI_INVALID_ADDRESS; + 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"; + // optimize usual case where cie is same for all FDEs + if ( cieStart != cieInfo.cieStart ) { + const char* err = CFI_Parser<A>::parseCIE(addressSpace, cieStart, &cieInfo); + if ( err != NULL ) + return err; + } + entry->u.fdeInfo.cie.targetAddress = cieStart; + entry->u.fdeInfo.cie.offsetInCFI = p-currentCFI; + entry->u.fdeInfo.cie.encodingOfTargetAddress = 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->u.fdeInfo.function.targetAddress = pcStart; + entry->u.fdeInfo.function.offsetInCFI = offsetOfFunctionAddress; + entry->u.fdeInfo.function.encodingOfTargetAddress = cieInfo.pointerEncoding; + // 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; + pint_t offsetOfLSDAAddress = p-currentCFI; + entry->u.fdeInfo.lsda.targetAddress = addressSpace.getEncodedP(p, nextCFI, cieInfo.lsdaEncoding); + entry->u.fdeInfo.lsda.offsetInCFI = offsetOfLSDAAddress; + entry->u.fdeInfo.lsda.encodingOfTargetAddress = cieInfo.lsdaEncoding; + } + } + p = endOfAug; + } + // compute compact unwind encoding + typename CFI_Parser<A>::FDE_Info fdeInfo; + fdeInfo.fdeStart = currentCFI; + fdeInfo.fdeLength = nextCFI - currentCFI; + fdeInfo.fdeInstructions = p; + fdeInfo.pcStart = pcStart; + fdeInfo.pcEnd = pcStart + pcRange; + fdeInfo.lsda = entry->u.fdeInfo.lsda.targetAddress; + typename CFI_Parser<A>::PrologInfo prolog; + R dummy; // for proper selection of architecture specific functions + if ( CFI_Parser<A>::parseFDEInstructions(addressSpace, fdeInfo, cieInfo, CFI_INVALID_ADDRESS, &prolog) ) { + char warningBuffer[1024]; + entry->u.fdeInfo.compactUnwindInfo = createCompactEncodingFromProlog(addressSpace, fdeInfo.pcStart, dummy, prolog, warningBuffer); + if ( fdeInfo.lsda != CFI_INVALID_ADDRESS ) + entry->u.fdeInfo.compactUnwindInfo |= UNWIND_HAS_LSDA; + if ( warningBuffer[0] != '\0' ) + warn(ref, fdeInfo.pcStart, warningBuffer); + } + else { + warn(ref, CFI_INVALID_ADDRESS, "dwarf unwind instructions could not be parsed"); + entry->u.fdeInfo.compactUnwindInfo = encodeToUseDwarf(dummy); + } + ++entry; + } + p = nextCFI; + } + if ( entry != end ) + return "wrong entry count for parseCFIs"; + return NULL; // success +} + + + + +template <typename A, typename R> +compact_unwind_encoding_t DwarfInstructions<A,R>::createCompactEncodingFromFDE(A& addressSpace, pint_t fdeStart, + pint_t* lsda, pint_t* personality, + char warningBuffer[1024]) +{ + typename CFI_Parser<A>::FDE_Info fdeInfo; + typename CFI_Parser<A>::CIE_Info cieInfo; + R dummy; // for proper selection of architecture specific functions + if ( CFI_Parser<A>::decodeFDE(addressSpace, fdeStart, &fdeInfo, &cieInfo) == NULL ) { + typename CFI_Parser<A>::PrologInfo prolog; + if ( CFI_Parser<A>::parseFDEInstructions(addressSpace, fdeInfo, cieInfo, CFI_INVALID_ADDRESS, &prolog) ) { + *lsda = fdeInfo.lsda; + *personality = cieInfo.personality; + compact_unwind_encoding_t encoding; + encoding = createCompactEncodingFromProlog(addressSpace, fdeInfo.pcStart, dummy, prolog, warningBuffer); + if ( fdeInfo.lsda != 0 ) + encoding |= UNWIND_HAS_LSDA; + return encoding; + } + else { + strcpy(warningBuffer, "dwarf unwind instructions could not be parsed"); + return encodeToUseDwarf(dummy); + } + } + else { + strcpy(warningBuffer, "dwarf FDE could not be parsed"); + return encodeToUseDwarf(dummy); + } +} + + +template <typename A, typename R> +typename A::pint_t DwarfInstructions<A,R>::getSavedRegister(A& addressSpace, const R& registers, pint_t cfa, + const typename CFI_Parser<A>::RegisterLocation& savedReg) +{ + switch ( savedReg.location ) { + case CFI_Parser<A>::kRegisterInCFA: + return addressSpace.getP(cfa + savedReg.value); + + case CFI_Parser<A>::kRegisterAtExpression: + return addressSpace.getP(evaluateExpression(savedReg.value, addressSpace, registers, cfa)); + + case CFI_Parser<A>::kRegisterIsExpression: + return evaluateExpression(savedReg.value, addressSpace, registers, cfa); + + case CFI_Parser<A>::kRegisterInRegister: + return registers.getRegister(savedReg.value); + + case CFI_Parser<A>::kRegisterUnused: + case CFI_Parser<A>::kRegisterOffsetFromCFA: + // FIX ME + break; + } + ABORT("unsupported restore location for register"); +} + +template <typename A, typename R> +double DwarfInstructions<A,R>::getSavedFloatRegister(A& addressSpace, const R& registers, pint_t cfa, + const typename CFI_Parser<A>::RegisterLocation& savedReg) +{ + switch ( savedReg.location ) { + case CFI_Parser<A>::kRegisterInCFA: + return addressSpace.getDouble(cfa + savedReg.value); + + case CFI_Parser<A>::kRegisterAtExpression: + return addressSpace.getDouble(evaluateExpression(savedReg.value, addressSpace, registers, cfa)); + + case CFI_Parser<A>::kRegisterIsExpression: + case CFI_Parser<A>::kRegisterUnused: + case CFI_Parser<A>::kRegisterOffsetFromCFA: + case CFI_Parser<A>::kRegisterInRegister: + // FIX ME + break; + } + ABORT("unsupported restore location for float register"); +} + +template <typename A, typename R> +v128 DwarfInstructions<A,R>::getSavedVectorRegister(A& addressSpace, const R& registers, pint_t cfa, + const typename CFI_Parser<A>::RegisterLocation& savedReg) +{ + switch ( savedReg.location ) { + case CFI_Parser<A>::kRegisterInCFA: + return addressSpace.getVector(cfa + savedReg.value); + + case CFI_Parser<A>::kRegisterAtExpression: + return addressSpace.getVector(evaluateExpression(savedReg.value, addressSpace, registers, cfa)); + + case CFI_Parser<A>::kRegisterIsExpression: + case CFI_Parser<A>::kRegisterUnused: + case CFI_Parser<A>::kRegisterOffsetFromCFA: + case CFI_Parser<A>::kRegisterInRegister: + // FIX ME + break; + } + ABORT("unsupported restore location for vector register"); +} + + +template <typename A, typename R> +int DwarfInstructions<A,R>::stepWithDwarf(A& addressSpace, pint_t pc, pint_t fdeStart, R& registers) +{ + //fprintf(stderr, "stepWithDwarf(pc=0x%0llX, fdeStart=0x%0llX)\n", (uint64_t)pc, (uint64_t)fdeStart); + typename CFI_Parser<A>::FDE_Info fdeInfo; + typename CFI_Parser<A>::CIE_Info cieInfo; + if ( CFI_Parser<A>::decodeFDE(addressSpace, fdeStart, &fdeInfo, &cieInfo) == NULL ) { + typename CFI_Parser<A>::PrologInfo prolog; + if ( CFI_Parser<A>::parseFDEInstructions(addressSpace, fdeInfo, cieInfo, pc, &prolog) ) { + R newRegisters = registers; + + // get pointer to cfa (architecture specific) + pint_t cfa = getCFA(addressSpace, prolog, registers); + + // restore registers that dwarf says were saved + pint_t returnAddress = 0; + for (int i=0; i <= lastRestoreReg(newRegisters); ++i) { + if ( prolog.savedRegisters[i].location != CFI_Parser<A>::kRegisterUnused ) { + if ( registers.validFloatRegister(i) ) + newRegisters.setFloatRegister(i, getSavedFloatRegister(addressSpace, registers, cfa, prolog.savedRegisters[i])); + else if ( registers.validVectorRegister(i) ) + newRegisters.setVectorRegister(i, getSavedVectorRegister(addressSpace, registers, cfa, prolog.savedRegisters[i])); + else if ( isReturnAddressRegister(i, registers) ) + returnAddress = getSavedRegister(addressSpace, registers, cfa, prolog.savedRegisters[i]); + else if ( registers.validRegister(i) ) + newRegisters.setRegister(i, getSavedRegister(addressSpace, registers, cfa, prolog.savedRegisters[i])); + else + return UNW_EBADREG; + } + } + + // by definition the CFA is the stack pointer at the call site, so restoring SP means setting it to CFA + newRegisters.setSP(cfa); + + // return address is address after call site instruction, so setting IP to that does a return + newRegisters.setIP(returnAddress); + + // do the actual step by replacing the register set with the new ones + registers = newRegisters; + + return UNW_STEP_SUCCESS; + } + } + return UNW_EBADFRAME; +} + + + +template <typename A, typename R> +typename A::pint_t DwarfInstructions<A,R>::evaluateExpression(pint_t expression, A& addressSpace, + const R& registers, pint_t initialStackValue) +{ + const bool log = false; + pint_t p = expression; + pint_t expressionEnd = expression+20; // just need something until length is read + uint64_t length = addressSpace.getULEB128(p, expressionEnd); + expressionEnd = p + length; + if (log) fprintf(stderr, "evaluateExpression(): length=%llu\n", length); + pint_t stack[100]; + pint_t* sp = stack; + *(++sp) = initialStackValue; + + while ( p < expressionEnd ) { + if (log) { + for(pint_t* t = sp; t > stack; --t) { + fprintf(stderr, "sp[] = 0x%llX\n", (uint64_t)(*t)); + } + } + uint8_t opcode = addressSpace.get8(p++); + sint_t svalue; + pint_t value; + uint32_t reg; + switch (opcode) { + case DW_OP_addr: + // push immediate address sized value + value = addressSpace.getP(p); + p += sizeof(pint_t); + *(++sp) = value; + if (log) fprintf(stderr, "push 0x%llX\n", (uint64_t)value); + break; + + case DW_OP_deref: + // pop stack, dereference, push result + value = *sp--; + *(++sp) = addressSpace.getP(value); + if (log) fprintf(stderr, "dereference 0x%llX\n", (uint64_t)value); + break; + + case DW_OP_const1u: + // push immediate 1 byte value + value = addressSpace.get8(p); + p += 1; + *(++sp) = value; + if (log) fprintf(stderr, "push 0x%llX\n", (uint64_t)value); + break; + + case DW_OP_const1s: + // push immediate 1 byte signed value + svalue = (int8_t)addressSpace.get8(p); + p += 1; + *(++sp) = svalue; + if (log) fprintf(stderr, "push 0x%llX\n", (uint64_t)svalue); + break; + + case DW_OP_const2u: + // push immediate 2 byte value + value = addressSpace.get16(p); + p += 2; + *(++sp) = value; + if (log) fprintf(stderr, "push 0x%llX\n", (uint64_t)value); + break; + + case DW_OP_const2s: + // push immediate 2 byte signed value + svalue = (int16_t)addressSpace.get16(p); + p += 2; + *(++sp) = svalue; + if (log) fprintf(stderr, "push 0x%llX\n", (uint64_t)svalue); + break; + + case DW_OP_const4u: + // push immediate 4 byte value + value = addressSpace.get32(p); + p += 4; + *(++sp) = value; + if (log) fprintf(stderr, "push 0x%llX\n", (uint64_t)value); + break; + + case DW_OP_const4s: + // push immediate 4 byte signed value + svalue = (int32_t)addressSpace.get32(p); + p += 4; + *(++sp) = svalue; + if (log) fprintf(stderr, "push 0x%llX\n", (uint64_t)svalue); + break; + + case DW_OP_const8u: + // push immediate 8 byte value + value = addressSpace.get64(p); + p += 8; + *(++sp) = value; + if (log) fprintf(stderr, "push 0x%llX\n", (uint64_t)value); + break; + + case DW_OP_const8s: + // push immediate 8 byte signed value + value = (int32_t)addressSpace.get64(p); + p += 8; + *(++sp) = value; + if (log) fprintf(stderr, "push 0x%llX\n", (uint64_t)value); + break; + + case DW_OP_constu: + // push immediate ULEB128 value + value = addressSpace.getULEB128(p, expressionEnd); + *(++sp) = value; + if (log) fprintf(stderr, "push 0x%llX\n", (uint64_t)value); + break; + + case DW_OP_consts: + // push immediate SLEB128 value + svalue = addressSpace.getSLEB128(p, expressionEnd); + *(++sp) = svalue; + if (log) fprintf(stderr, "push 0x%llX\n", (uint64_t)svalue); + break; + + case DW_OP_dup: + // push top of stack + value = *sp; + *(++sp) = value; + if (log) fprintf(stderr, "duplicate top of stack\n"); + break; + + case DW_OP_drop: + // pop + --sp; + if (log) fprintf(stderr, "pop top of stack\n"); + break; + + case DW_OP_over: + // dup second + value = sp[-1]; + *(++sp) = value; + if (log) fprintf(stderr, "duplicate second in stack\n"); + break; + + case DW_OP_pick: + // pick from + reg = addressSpace.get8(p); + p += 1; + value = sp[-reg]; + *(++sp) = value; + if (log) fprintf(stderr, "duplicate %d in stack\n", reg); + break; + + case DW_OP_swap: + // swap top two + value = sp[0]; + sp[0] = sp[-1]; + sp[-1] = value; + if (log) fprintf(stderr, "swap top of stack\n"); + break; + + case DW_OP_rot: + // rotate top three + value = sp[0]; + sp[0] = sp[-1]; + sp[-1] = sp[-2]; + sp[-2] = value; + if (log) fprintf(stderr, "rotate top three of stack\n"); + break; + + case DW_OP_xderef: + // pop stack, dereference, push result + value = *sp--; + *sp = *((uint64_t*)value); + if (log) fprintf(stderr, "x-dereference 0x%llX\n", (uint64_t)value); + break; + + case DW_OP_abs: + svalue = *sp; + if ( svalue < 0 ) + *sp = -svalue; + if (log) fprintf(stderr, "abs\n"); + break; + + case DW_OP_and: + value = *sp--; + *sp &= value; + if (log) fprintf(stderr, "and\n"); + break; + + case DW_OP_div: + svalue = *sp--; + *sp = *sp / svalue; + if (log) fprintf(stderr, "div\n"); + break; + + case DW_OP_minus: + svalue = *sp--; + *sp = *sp - svalue; + if (log) fprintf(stderr, "minus\n"); + break; + + case DW_OP_mod: + svalue = *sp--; + *sp = *sp % svalue; + if (log) fprintf(stderr, "module\n"); + break; + + case DW_OP_mul: + svalue = *sp--; + *sp = *sp * svalue; + if (log) fprintf(stderr, "mul\n"); + break; + + case DW_OP_neg: + *sp = 0 - *sp; + if (log) fprintf(stderr, "neg\n"); + break; + + case DW_OP_not: + svalue = *sp; + *sp = ~svalue; + if (log) fprintf(stderr, "not\n"); + break; + + case DW_OP_or: + value = *sp--; + *sp |= value; + if (log) fprintf(stderr, "or\n"); + break; + + case DW_OP_plus: + value = *sp--; + *sp += value; + if (log) fprintf(stderr, "plus\n"); + break; + + case DW_OP_plus_uconst: + // pop stack, add uelb128 constant, push result + *sp += addressSpace.getULEB128(p, expressionEnd); + if (log) fprintf(stderr, "add constant\n"); + break; + + case DW_OP_shl: + value = *sp--; + *sp = *sp << value; + if (log) fprintf(stderr, "shift left\n"); + break; + + case DW_OP_shr: + value = *sp--; + *sp = *sp >> value; + if (log) fprintf(stderr, "shift left\n"); + break; + + case DW_OP_shra: + value = *sp--; + svalue = *sp; + *sp = svalue >> value; + if (log) fprintf(stderr, "shift left arithmetric\n"); + break; + + case DW_OP_xor: + value = *sp--; + *sp ^= value; + if (log) fprintf(stderr, "xor\n"); + break; + + case DW_OP_skip: + svalue = (int16_t)addressSpace.get16(p); + p += 2; + p += svalue; + if (log) fprintf(stderr, "skip %lld\n", (uint64_t)svalue); + break; + + case DW_OP_bra: + svalue = (int16_t)addressSpace.get16(p); + p += 2; + if ( *sp-- ) + p += svalue; + if (log) fprintf(stderr, "bra %lld\n", (uint64_t)svalue); + break; + + case DW_OP_eq: + value = *sp--; + *sp = (*sp == value); + if (log) fprintf(stderr, "eq\n"); + break; + + case DW_OP_ge: + value = *sp--; + *sp = (*sp >= value); + if (log) fprintf(stderr, "ge\n"); + break; + + case DW_OP_gt: + value = *sp--; + *sp = (*sp > value); + if (log) fprintf(stderr, "gt\n"); + break; + + case DW_OP_le: + value = *sp--; + *sp = (*sp <= value); + if (log) fprintf(stderr, "le\n"); + break; + + case DW_OP_lt: + value = *sp--; + *sp = (*sp < value); + if (log) fprintf(stderr, "lt\n"); + break; + + case DW_OP_ne: + value = *sp--; + *sp = (*sp != value); + if (log) fprintf(stderr, "ne\n"); + break; + + case DW_OP_lit0: + case DW_OP_lit1: + case DW_OP_lit2: + case DW_OP_lit3: + case DW_OP_lit4: + case DW_OP_lit5: + case DW_OP_lit6: + case DW_OP_lit7: + case DW_OP_lit8: + case DW_OP_lit9: + case DW_OP_lit10: + case DW_OP_lit11: + case DW_OP_lit12: + case DW_OP_lit13: + case DW_OP_lit14: + case DW_OP_lit15: + case DW_OP_lit16: + case DW_OP_lit17: + case DW_OP_lit18: + case DW_OP_lit19: + case DW_OP_lit20: + case DW_OP_lit21: + case DW_OP_lit22: + case DW_OP_lit23: + case DW_OP_lit24: + case DW_OP_lit25: + case DW_OP_lit26: + case DW_OP_lit27: + case DW_OP_lit28: + case DW_OP_lit29: + case DW_OP_lit30: + case DW_OP_lit31: + value = opcode - DW_OP_lit0; + *(++sp) = value; + if (log) fprintf(stderr, "push literal 0x%llX\n", (uint64_t)value); + break; + + case DW_OP_reg0: + case DW_OP_reg1: + case DW_OP_reg2: + case DW_OP_reg3: + case DW_OP_reg4: + case DW_OP_reg5: + case DW_OP_reg6: + case DW_OP_reg7: + case DW_OP_reg8: + case DW_OP_reg9: + case DW_OP_reg10: + case DW_OP_reg11: + case DW_OP_reg12: + case DW_OP_reg13: + case DW_OP_reg14: + case DW_OP_reg15: + case DW_OP_reg16: + case DW_OP_reg17: + case DW_OP_reg18: + case DW_OP_reg19: + case DW_OP_reg20: + case DW_OP_reg21: + case DW_OP_reg22: + case DW_OP_reg23: + case DW_OP_reg24: + case DW_OP_reg25: + case DW_OP_reg26: + case DW_OP_reg27: + case DW_OP_reg28: + case DW_OP_reg29: + case DW_OP_reg30: + case DW_OP_reg31: + reg = opcode - DW_OP_reg0; + *(++sp) = registers.getRegister(reg); + if (log) fprintf(stderr, "push reg %d\n", reg); + break; + + case DW_OP_regx: + reg = addressSpace.getULEB128(p, expressionEnd); + *(++sp) = registers.getRegister(reg); + if (log) fprintf(stderr, "push reg %d + 0x%llX\n", reg, (uint64_t)svalue); + break; + + case DW_OP_breg0: + case DW_OP_breg1: + case DW_OP_breg2: + case DW_OP_breg3: + case DW_OP_breg4: + case DW_OP_breg5: + case DW_OP_breg6: + case DW_OP_breg7: + case DW_OP_breg8: + case DW_OP_breg9: + case DW_OP_breg10: + case DW_OP_breg11: + case DW_OP_breg12: + case DW_OP_breg13: + case DW_OP_breg14: + case DW_OP_breg15: + case DW_OP_breg16: + case DW_OP_breg17: + case DW_OP_breg18: + case DW_OP_breg19: + case DW_OP_breg20: + case DW_OP_breg21: + case DW_OP_breg22: + case DW_OP_breg23: + case DW_OP_breg24: + case DW_OP_breg25: + case DW_OP_breg26: + case DW_OP_breg27: + case DW_OP_breg28: + case DW_OP_breg29: + case DW_OP_breg30: + case DW_OP_breg31: + reg = opcode - DW_OP_breg0; + svalue = addressSpace.getSLEB128(p, expressionEnd); + *(++sp) = registers.getRegister(reg) + svalue; + if (log) fprintf(stderr, "push reg %d + 0x%llX\n", reg, (uint64_t)svalue); + break; + + case DW_OP_bregx: + reg = addressSpace.getULEB128(p, expressionEnd); + svalue = addressSpace.getSLEB128(p, expressionEnd); + *(++sp) = registers.getRegister(reg) + svalue; + if (log) fprintf(stderr, "push reg %d + 0x%llX\n", reg, (uint64_t)svalue); + break; + + case DW_OP_fbreg: + ABORT("DW_OP_fbreg not implemented"); + break; + + case DW_OP_piece: + ABORT("DW_OP_piece not implemented"); + break; + + case DW_OP_deref_size: + // pop stack, dereference, push result + value = *sp--; + switch ( addressSpace.get8(p++) ) { + case 1: + value = addressSpace.get8(value); + break; + case 2: + value = addressSpace.get16(value); + break; + case 4: + value = addressSpace.get32(value); + break; + case 8: + value = addressSpace.get64(value); + break; + default: + ABORT("DW_OP_deref_size with bad size"); + } + *(++sp) = value; + if (log) fprintf(stderr, "sized dereference 0x%llX\n", (uint64_t)value); + break; + + case DW_OP_xderef_size: + case DW_OP_nop: + case DW_OP_push_object_addres: + case DW_OP_call2: + case DW_OP_call4: + case DW_OP_call_ref: + default: + ABORT("dwarf opcode not implemented"); + } + + } + if (log) fprintf(stderr, "expression evaluates to 0x%llX\n", (uint64_t)*sp); + return *sp; +} + + + +// +// x86_64 specific functions +// + +template <typename A, typename R> +int DwarfInstructions<A,R>::lastRestoreReg(const Registers_x86_64&) +{ + COMPILE_TIME_ASSERT( (int)CFI_Parser<A>::kMaxRegisterNumber > (int)DW_X86_64_RET_ADDR ); + return DW_X86_64_RET_ADDR; +} + +template <typename A, typename R> +bool DwarfInstructions<A,R>::isReturnAddressRegister(int regNum, const Registers_x86_64&) +{ + return (regNum == DW_X86_64_RET_ADDR); +} + +template <typename A, typename R> +typename A::pint_t DwarfInstructions<A,R>::getCFA(A& addressSpace, const typename CFI_Parser<A>::PrologInfo& prolog, + const Registers_x86_64& registers) +{ + if ( prolog.cfaRegister != 0 ) + return registers.getRegister(prolog.cfaRegister) + prolog.cfaRegisterOffset; + else if ( prolog.cfaExpression != 0 ) + return evaluateExpression(prolog.cfaExpression, addressSpace, registers, 0); + else + ABORT("getCFA(): unknown location for x86_64 cfa"); +} + + + +template <typename A, typename R> +compact_unwind_encoding_t DwarfInstructions<A,R>::encodeToUseDwarf(const Registers_x86_64&) +{ + return UNWIND_X86_64_MODE_DWARF; +} + +template <typename A, typename R> +compact_unwind_encoding_t DwarfInstructions<A,R>::encodeToUseDwarf(const Registers_x86&) +{ + return UNWIND_X86_MODE_DWARF; +} + + + +template <typename A, typename R> +uint32_t DwarfInstructions<A,R>::getRBPEncodedRegister(uint32_t reg, int32_t regOffsetFromBaseOffset, bool& failure) +{ + if ( (regOffsetFromBaseOffset < 0) || (regOffsetFromBaseOffset > 32) ) { + failure = true; + return 0; + } + unsigned int slotIndex = regOffsetFromBaseOffset/8; + + switch ( reg ) { + case UNW_X86_64_RBX: + return UNWIND_X86_64_REG_RBX << (slotIndex*3); + case UNW_X86_64_R12: + return UNWIND_X86_64_REG_R12 << (slotIndex*3); + case UNW_X86_64_R13: + return UNWIND_X86_64_REG_R13 << (slotIndex*3); + case UNW_X86_64_R14: + return UNWIND_X86_64_REG_R14 << (slotIndex*3); + case UNW_X86_64_R15: + return UNWIND_X86_64_REG_R15 << (slotIndex*3); + } + + // invalid register + failure = true; + return 0; +} + + + +template <typename A, typename R> +compact_unwind_encoding_t DwarfInstructions<A,R>::createCompactEncodingFromProlog(A& addressSpace, pint_t funcAddr, + const Registers_x86_64& r, const typename CFI_Parser<A>::PrologInfo& prolog, + char warningBuffer[1024]) +{ + warningBuffer[0] = '\0'; + + // don't create compact unwind info for unsupported dwarf kinds + if ( prolog.registerSavedMoreThanOnce ) { + strcpy(warningBuffer, "register saved more than once (might be shrink wrap)"); + return UNWIND_X86_64_MODE_DWARF; + } + if ( prolog.cfaOffsetWasNegative ) { + strcpy(warningBuffer, "cfa had negative offset (dwarf might contain epilog)"); + return UNWIND_X86_64_MODE_DWARF; + } + if ( prolog.spExtraArgSize != 0 ) { + strcpy(warningBuffer, "dwarf uses DW_CFA_GNU_args_size"); + return UNWIND_X86_64_MODE_DWARF; + } + + // figure out which kind of frame this function uses + bool standardRBPframe = ( + (prolog.cfaRegister == UNW_X86_64_RBP) + && (prolog.cfaRegisterOffset == 16) + && (prolog.savedRegisters[UNW_X86_64_RBP].location == CFI_Parser<A>::kRegisterInCFA) + && (prolog.savedRegisters[UNW_X86_64_RBP].value == -16) ); + bool standardRSPframe = (prolog.cfaRegister == UNW_X86_64_RSP); + if ( !standardRBPframe && !standardRSPframe ) { + // no compact encoding for this + strcpy(warningBuffer, "does not use RBP or RSP based frame"); + return UNWIND_X86_64_MODE_DWARF; + } + + // scan which registers are saved + int saveRegisterCount = 0; + bool rbxSaved = false; + bool r12Saved = false; + bool r13Saved = false; + bool r14Saved = false; + bool r15Saved = false; + bool rbpSaved = false; + for (int i=0; i < 64; ++i) { + if ( prolog.savedRegisters[i].location != CFI_Parser<A>::kRegisterUnused ) { + if ( prolog.savedRegisters[i].location != CFI_Parser<A>::kRegisterInCFA ) { + sprintf(warningBuffer, "register %d saved somewhere other that in frame", i); + return UNWIND_X86_64_MODE_DWARF; + } + switch (i) { + case UNW_X86_64_RBX: + rbxSaved = true; + ++saveRegisterCount; + break; + case UNW_X86_64_R12: + r12Saved = true; + ++saveRegisterCount; + break; + case UNW_X86_64_R13: + r13Saved = true; + ++saveRegisterCount; + break; + case UNW_X86_64_R14: + r14Saved = true; + ++saveRegisterCount; + break; + case UNW_X86_64_R15: + r15Saved = true; + ++saveRegisterCount; + break; + case UNW_X86_64_RBP: + rbpSaved = true; + ++saveRegisterCount; + break; + case DW_X86_64_RET_ADDR: + break; + default: + sprintf(warningBuffer, "non-standard register %d being saved in prolog", i); + return UNWIND_X86_64_MODE_DWARF; + } + } + } + const int64_t cfaOffsetRBX = prolog.savedRegisters[UNW_X86_64_RBX].value; + const int64_t cfaOffsetR12 = prolog.savedRegisters[UNW_X86_64_R12].value; + const int64_t cfaOffsetR13 = prolog.savedRegisters[UNW_X86_64_R13].value; + const int64_t cfaOffsetR14 = prolog.savedRegisters[UNW_X86_64_R14].value; + const int64_t cfaOffsetR15 = prolog.savedRegisters[UNW_X86_64_R15].value; + const int64_t cfaOffsetRBP = prolog.savedRegisters[UNW_X86_64_RBP].value; + + // encode standard RBP frames + compact_unwind_encoding_t encoding = 0; + if ( standardRBPframe ) { + // | | + // +--------------+ <- CFA + // | ret addr | + // +--------------+ + // | rbp | + // +--------------+ <- rbp + // ~ ~ + // +--------------+ + // | saved reg3 | + // +--------------+ <- CFA - offset+16 + // | saved reg2 | + // +--------------+ <- CFA - offset+8 + // | saved reg1 | + // +--------------+ <- CFA - offset + // | | + // +--------------+ + // | | + // <- rsp + // + encoding = UNWIND_X86_64_MODE_RBP_FRAME; + + // find save location of farthest register from rbp + int furthestCfaOffset = 0; + if ( rbxSaved & (cfaOffsetRBX < furthestCfaOffset) ) + furthestCfaOffset = cfaOffsetRBX; + if ( r12Saved & (cfaOffsetR12 < furthestCfaOffset) ) + furthestCfaOffset = cfaOffsetR12; + if ( r13Saved & (cfaOffsetR13 < furthestCfaOffset) ) + furthestCfaOffset = cfaOffsetR13; + if ( r14Saved & (cfaOffsetR14 < furthestCfaOffset) ) + furthestCfaOffset = cfaOffsetR14; + if ( r15Saved & (cfaOffsetR15 < furthestCfaOffset) ) + furthestCfaOffset = cfaOffsetR15; + + if ( furthestCfaOffset == 0 ) { + // no registers saved, nothing more to encode + return encoding; + } + + // add stack offset to encoding + int rbpOffset = furthestCfaOffset + 16; + int encodedOffset = rbpOffset/(-8); + if ( encodedOffset > 255 ) { + strcpy(warningBuffer, "offset of saved registers too far to encode"); + return UNWIND_X86_64_MODE_DWARF; + } + encoding |= (encodedOffset << __builtin_ctz(UNWIND_X86_64_RBP_FRAME_OFFSET)); + + // add register saved from each stack location + bool encodingFailure = false; + if ( rbxSaved ) + encoding |= getRBPEncodedRegister(UNW_X86_64_RBX, cfaOffsetRBX - furthestCfaOffset, encodingFailure); + if ( r12Saved ) + encoding |= getRBPEncodedRegister(UNW_X86_64_R12, cfaOffsetR12 - furthestCfaOffset, encodingFailure); + if ( r13Saved ) + encoding |= getRBPEncodedRegister(UNW_X86_64_R13, cfaOffsetR13 - furthestCfaOffset, encodingFailure); + if ( r14Saved ) + encoding |= getRBPEncodedRegister(UNW_X86_64_R14, cfaOffsetR14 - furthestCfaOffset, encodingFailure); + if ( r15Saved ) + encoding |= getRBPEncodedRegister(UNW_X86_64_R15, cfaOffsetR15 - furthestCfaOffset, encodingFailure); + + if ( encodingFailure ){ + strcpy(warningBuffer, "saved registers not contiguous"); + return UNWIND_X86_64_MODE_DWARF; + } + + return encoding; + } + else { + // | | + // +--------------+ <- CFA + // | ret addr | + // +--------------+ + // | saved reg1 | + // +--------------+ <- CFA - 16 + // | saved reg2 | + // +--------------+ <- CFA - 24 + // | saved reg3 | + // +--------------+ <- CFA - 32 + // | saved reg4 | + // +--------------+ <- CFA - 40 + // | saved reg5 | + // +--------------+ <- CFA - 48 + // | saved reg6 | + // +--------------+ <- CFA - 56 + // | | + // <- esp + // + + // for RSP based frames we need to encode stack size in unwind info + encoding = UNWIND_X86_64_MODE_STACK_IMMD; + uint64_t stackValue = prolog.cfaRegisterOffset / 8; + uint32_t stackAdjust = 0; + bool immedStackSize = true; + const uint32_t stackMaxImmedValue = EXTRACT_BITS(0xFFFFFFFF,UNWIND_X86_64_FRAMELESS_STACK_SIZE); + if ( stackValue > stackMaxImmedValue ) { + // stack size is too big to fit as an immediate value, so encode offset of subq instruction in function + pint_t functionContentAdjustStackIns = funcAddr + prolog.codeOffsetAtStackDecrement - 4; + uint32_t stackDecrementInCode = addressSpace.get32(functionContentAdjustStackIns); + stackAdjust = (prolog.cfaRegisterOffset - stackDecrementInCode)/8; + stackValue = functionContentAdjustStackIns - funcAddr; + immedStackSize = false; + if ( stackAdjust > 7 ) { + strcpy(warningBuffer, "stack subq instruction is too different from dwarf stack size"); + return UNWIND_X86_64_MODE_DWARF; + } + encoding = UNWIND_X86_64_MODE_STACK_IND; + } + + + // validate that saved registers are all within 6 slots abutting return address + int registers[6]; + for (int i=0; i < 6;++i) + registers[i] = 0; + if ( r15Saved ) { + if ( cfaOffsetR15 < -56 ) { + strcpy(warningBuffer, "r15 is saved too far from return address"); + return UNWIND_X86_64_MODE_DWARF; + } + registers[(cfaOffsetR15+56)/8] = UNWIND_X86_64_REG_R15; + } + if ( r14Saved ) { + if ( cfaOffsetR14 < -56 ) { + strcpy(warningBuffer, "r14 is saved too far from return address"); + return UNWIND_X86_64_MODE_DWARF; + } + registers[(cfaOffsetR14+56)/8] = UNWIND_X86_64_REG_R14; + } + if ( r13Saved ) { + if ( cfaOffsetR13 < -56 ) { + strcpy(warningBuffer, "r13 is saved too far from return address"); + return UNWIND_X86_64_MODE_DWARF; + } + registers[(cfaOffsetR13+56)/8] = UNWIND_X86_64_REG_R13; + } + if ( r12Saved ) { + if ( cfaOffsetR12 < -56 ) { + strcpy(warningBuffer, "r12 is saved too far from return address"); + return UNWIND_X86_64_MODE_DWARF; + } + registers[(cfaOffsetR12+56)/8] = UNWIND_X86_64_REG_R12; + } + if ( rbxSaved ) { + if ( cfaOffsetRBX < -56 ) { + strcpy(warningBuffer, "rbx is saved too far from return address"); + return UNWIND_X86_64_MODE_DWARF; + } + registers[(cfaOffsetRBX+56)/8] = UNWIND_X86_64_REG_RBX; + } + if ( rbpSaved ) { + if ( cfaOffsetRBP < -56 ) { + strcpy(warningBuffer, "rbp is saved too far from return address"); + return UNWIND_X86_64_MODE_DWARF; + } + registers[(cfaOffsetRBP+56)/8] = UNWIND_X86_64_REG_RBP; + } + + // validate that saved registers are contiguous and abut return address on stack + for (int i=0; i < saveRegisterCount; ++i) { + if ( registers[5-i] == 0 ) { + strcpy(warningBuffer, "registers not save contiguously in stack"); + return UNWIND_X86_64_MODE_DWARF; + } + } + + // encode register permutation + // the 10-bits are encoded differently depending on the number of registers saved + int renumregs[6]; + for (int i=6-saveRegisterCount; i < 6; ++i) { + int countless = 0; + for (int j=6-saveRegisterCount; j < i; ++j) { + if ( registers[j] < registers[i] ) + ++countless; + } + renumregs[i] = registers[i] - countless -1; + } + uint32_t permutationEncoding = 0; + switch ( saveRegisterCount ) { + case 6: + permutationEncoding |= (120*renumregs[0] + 24*renumregs[1] + 6*renumregs[2] + 2*renumregs[3] + renumregs[4]); + break; + case 5: + permutationEncoding |= (120*renumregs[1] + 24*renumregs[2] + 6*renumregs[3] + 2*renumregs[4] + renumregs[5]); + break; + case 4: + permutationEncoding |= (60*renumregs[2] + 12*renumregs[3] + 3*renumregs[4] + renumregs[5]); + break; + case 3: + permutationEncoding |= (20*renumregs[3] + 4*renumregs[4] + renumregs[5]); + break; + case 2: + permutationEncoding |= (5*renumregs[4] + renumregs[5]); + break; + case 1: + permutationEncoding |= (renumregs[5]); + break; + } + + encoding |= (stackValue << __builtin_ctz(UNWIND_X86_64_FRAMELESS_STACK_SIZE)); + encoding |= (stackAdjust << __builtin_ctz(UNWIND_X86_64_FRAMELESS_STACK_ADJUST)); + encoding |= (saveRegisterCount << __builtin_ctz(UNWIND_X86_64_FRAMELESS_STACK_REG_COUNT)); + encoding |= (permutationEncoding << __builtin_ctz(UNWIND_X86_64_FRAMELESS_STACK_REG_PERMUTATION)); + return encoding; + } +} + + + + +// +// x86 specific functions +// +template <typename A, typename R> +int DwarfInstructions<A,R>::lastRestoreReg(const Registers_x86&) +{ + COMPILE_TIME_ASSERT( (int)CFI_Parser<A>::kMaxRegisterNumber > (int)DW_X86_RET_ADDR ); + return DW_X86_RET_ADDR; +} + +template <typename A, typename R> +bool DwarfInstructions<A,R>::isReturnAddressRegister(int regNum, const Registers_x86&) +{ + return (regNum == DW_X86_RET_ADDR); +} + +template <typename A, typename R> +typename A::pint_t DwarfInstructions<A,R>::getCFA(A& addressSpace, const typename CFI_Parser<A>::PrologInfo& prolog, + const Registers_x86& registers) +{ + if ( prolog.cfaRegister != 0 ) + return registers.getRegister(prolog.cfaRegister) + prolog.cfaRegisterOffset; + else if ( prolog.cfaExpression != 0 ) + return evaluateExpression(prolog.cfaExpression, addressSpace, registers, 0); + else + ABORT("getCFA(): unknown location for x86 cfa"); +} + + + + + +template <typename A, typename R> +uint32_t DwarfInstructions<A,R>::getEBPEncodedRegister(uint32_t reg, int32_t regOffsetFromBaseOffset, bool& failure) +{ + if ( (regOffsetFromBaseOffset < 0) || (regOffsetFromBaseOffset > 16) ) { + failure = true; + return 0; + } + unsigned int slotIndex = regOffsetFromBaseOffset/4; + + switch ( reg ) { + case UNW_X86_EBX: + return UNWIND_X86_REG_EBX << (slotIndex*3); + case UNW_X86_ECX: + return UNWIND_X86_REG_ECX << (slotIndex*3); + case UNW_X86_EDX: + return UNWIND_X86_REG_EDX << (slotIndex*3); + case UNW_X86_EDI: + return UNWIND_X86_REG_EDI << (slotIndex*3); + case UNW_X86_ESI: + return UNWIND_X86_REG_ESI << (slotIndex*3); + } + + // invalid register + failure = true; + return 0; +} + +template <typename A, typename R> +compact_unwind_encoding_t DwarfInstructions<A,R>::createCompactEncodingFromProlog(A& addressSpace, pint_t funcAddr, + const Registers_x86& r, const typename CFI_Parser<A>::PrologInfo& prolog, + char warningBuffer[1024]) +{ + warningBuffer[0] = '\0'; + + // don't create compact unwind info for unsupported dwarf kinds + if ( prolog.registerSavedMoreThanOnce ) { + strcpy(warningBuffer, "register saved more than once (might be shrink wrap)"); + return UNWIND_X86_MODE_DWARF; + } + if ( prolog.spExtraArgSize != 0 ) { + strcpy(warningBuffer, "dwarf uses DW_CFA_GNU_args_size"); + return UNWIND_X86_MODE_DWARF; + } + + // figure out which kind of frame this function uses + bool standardEBPframe = ( + (prolog.cfaRegister == UNW_X86_EBP) + && (prolog.cfaRegisterOffset == 8) + && (prolog.savedRegisters[UNW_X86_EBP].location == CFI_Parser<A>::kRegisterInCFA) + && (prolog.savedRegisters[UNW_X86_EBP].value == -8) ); + bool standardESPframe = (prolog.cfaRegister == UNW_X86_ESP); + if ( !standardEBPframe && !standardESPframe ) { + // no compact encoding for this + strcpy(warningBuffer, "does not use EBP or ESP based frame"); + return UNWIND_X86_MODE_DWARF; + } + + // scan which registers are saved + int saveRegisterCount = 0; + bool ebxSaved = false; + bool ecxSaved = false; + bool edxSaved = false; + bool esiSaved = false; + bool ediSaved = false; + bool ebpSaved = false; + for (int i=0; i < 64; ++i) { + if ( prolog.savedRegisters[i].location != CFI_Parser<A>::kRegisterUnused ) { + if ( prolog.savedRegisters[i].location != CFI_Parser<A>::kRegisterInCFA ) { + sprintf(warningBuffer, "register %d saved somewhere other that in frame", i); + return UNWIND_X86_MODE_DWARF; + } + switch (i) { + case UNW_X86_EBX: + ebxSaved = true; + ++saveRegisterCount; + break; + case UNW_X86_ECX: + ecxSaved = true; + ++saveRegisterCount; + break; + case UNW_X86_EDX: + edxSaved = true; + ++saveRegisterCount; + break; + case UNW_X86_ESI: + esiSaved = true; + ++saveRegisterCount; + break; + case UNW_X86_EDI: + ediSaved = true; + ++saveRegisterCount; + break; + case UNW_X86_EBP: + ebpSaved = true; + ++saveRegisterCount; + break; + case DW_X86_RET_ADDR: + break; + default: + sprintf(warningBuffer, "non-standard register %d being saved in prolog", i); + return UNWIND_X86_MODE_DWARF; + } + } + } + const int32_t cfaOffsetEBX = prolog.savedRegisters[UNW_X86_EBX].value; + const int32_t cfaOffsetECX = prolog.savedRegisters[UNW_X86_ECX].value; + const int32_t cfaOffsetEDX = prolog.savedRegisters[UNW_X86_EDX].value; + const int32_t cfaOffsetEDI = prolog.savedRegisters[UNW_X86_EDI].value; + const int32_t cfaOffsetESI = prolog.savedRegisters[UNW_X86_ESI].value; + const int32_t cfaOffsetEBP = prolog.savedRegisters[UNW_X86_EBP].value; + + // encode standard RBP frames + compact_unwind_encoding_t encoding = 0; + if ( standardEBPframe ) { + // | | + // +--------------+ <- CFA + // | ret addr | + // +--------------+ + // | ebp | + // +--------------+ <- ebp + // ~ ~ + // +--------------+ + // | saved reg3 | + // +--------------+ <- CFA - offset+8 + // | saved reg2 | + // +--------------+ <- CFA - offset+e + // | saved reg1 | + // +--------------+ <- CFA - offset + // | | + // +--------------+ + // | | + // <- esp + // + encoding = UNWIND_X86_MODE_EBP_FRAME; + + // find save location of farthest register from ebp + int furthestCfaOffset = 0; + if ( ebxSaved & (cfaOffsetEBX < furthestCfaOffset) ) + furthestCfaOffset = cfaOffsetEBX; + if ( ecxSaved & (cfaOffsetECX < furthestCfaOffset) ) + furthestCfaOffset = cfaOffsetECX; + if ( edxSaved & (cfaOffsetEDX < furthestCfaOffset) ) + furthestCfaOffset = cfaOffsetEDX; + if ( ediSaved & (cfaOffsetEDI < furthestCfaOffset) ) + furthestCfaOffset = cfaOffsetEDI; + if ( esiSaved & (cfaOffsetESI < furthestCfaOffset) ) + furthestCfaOffset = cfaOffsetESI; + + if ( furthestCfaOffset == 0 ) { + // no registers saved, nothing more to encode + return encoding; + } + + // add stack offset to encoding + int ebpOffset = furthestCfaOffset + 8; + int encodedOffset = ebpOffset/(-4); + if ( encodedOffset > 255 ) { + strcpy(warningBuffer, "offset of saved registers too far to encode"); + return UNWIND_X86_MODE_DWARF; + } + encoding |= (encodedOffset << __builtin_ctz(UNWIND_X86_EBP_FRAME_OFFSET)); + + // add register saved from each stack location + bool encodingFailure = false; + if ( ebxSaved ) + encoding |= getEBPEncodedRegister(UNW_X86_EBX, cfaOffsetEBX - furthestCfaOffset, encodingFailure); + if ( ecxSaved ) + encoding |= getEBPEncodedRegister(UNW_X86_ECX, cfaOffsetECX - furthestCfaOffset, encodingFailure); + if ( edxSaved ) + encoding |= getEBPEncodedRegister(UNW_X86_EDX, cfaOffsetEDX - furthestCfaOffset, encodingFailure); + if ( ediSaved ) + encoding |= getEBPEncodedRegister(UNW_X86_EDI, cfaOffsetEDI - furthestCfaOffset, encodingFailure); + if ( esiSaved ) + encoding |= getEBPEncodedRegister(UNW_X86_ESI, cfaOffsetESI - furthestCfaOffset, encodingFailure); + + if ( encodingFailure ){ + strcpy(warningBuffer, "saved registers not contiguous"); + return UNWIND_X86_MODE_DWARF; + } + + return encoding; + } + else { + // | | + // +--------------+ <- CFA + // | ret addr | + // +--------------+ + // | saved reg1 | + // +--------------+ <- CFA - 8 + // | saved reg2 | + // +--------------+ <- CFA - 12 + // | saved reg3 | + // +--------------+ <- CFA - 16 + // | saved reg4 | + // +--------------+ <- CFA - 20 + // | saved reg5 | + // +--------------+ <- CFA - 24 + // | saved reg6 | + // +--------------+ <- CFA - 28 + // | | + // <- esp + // + + // for ESP based frames we need to encode stack size in unwind info + encoding = UNWIND_X86_MODE_STACK_IMMD; + uint64_t stackValue = prolog.cfaRegisterOffset / 4; + uint32_t stackAdjust = 0; + bool immedStackSize = true; + const uint32_t stackMaxImmedValue = EXTRACT_BITS(0xFFFFFFFF,UNWIND_X86_FRAMELESS_STACK_SIZE); + if ( stackValue > stackMaxImmedValue ) { + // stack size is too big to fit as an immediate value, so encode offset of subq instruction in function + pint_t functionContentAdjustStackIns = funcAddr + prolog.codeOffsetAtStackDecrement - 4; + uint32_t stackDecrementInCode = addressSpace.get32(functionContentAdjustStackIns); + stackAdjust = (prolog.cfaRegisterOffset - stackDecrementInCode)/4; + stackValue = functionContentAdjustStackIns - funcAddr; + immedStackSize = false; + if ( stackAdjust > 7 ) { + strcpy(warningBuffer, "stack subq instruction is too different from dwarf stack size"); + return UNWIND_X86_MODE_DWARF; + } + encoding = UNWIND_X86_MODE_STACK_IND; + } + + + // validate that saved registers are all within 6 slots abutting return address + int registers[6]; + for (int i=0; i < 6;++i) + registers[i] = 0; + if ( ebxSaved ) { + if ( cfaOffsetEBX < -28 ) { + strcpy(warningBuffer, "ebx is saved too far from return address"); + return UNWIND_X86_MODE_DWARF; + } + registers[(cfaOffsetEBX+28)/4] = UNWIND_X86_REG_EBX; + } + if ( ecxSaved ) { + if ( cfaOffsetECX < -28 ) { + strcpy(warningBuffer, "ecx is saved too far from return address"); + return UNWIND_X86_MODE_DWARF; + } + registers[(cfaOffsetECX+28)/4] = UNWIND_X86_REG_ECX; + } + if ( edxSaved ) { + if ( cfaOffsetEDX < -28 ) { + strcpy(warningBuffer, "edx is saved too far from return address"); + return UNWIND_X86_MODE_DWARF; + } + registers[(cfaOffsetEDX+28)/4] = UNWIND_X86_REG_EDX; + } + if ( ediSaved ) { + if ( cfaOffsetEDI < -28 ) { + strcpy(warningBuffer, "edi is saved too far from return address"); + return UNWIND_X86_MODE_DWARF; + } + registers[(cfaOffsetEDI+28)/4] = UNWIND_X86_REG_EDI; + } + if ( esiSaved ) { + if ( cfaOffsetESI < -28 ) { + strcpy(warningBuffer, "esi is saved too far from return address"); + return UNWIND_X86_MODE_DWARF; + } + registers[(cfaOffsetESI+28)/4] = UNWIND_X86_REG_ESI; + } + if ( ebpSaved ) { + if ( cfaOffsetEBP < -28 ) { + strcpy(warningBuffer, "ebp is saved too far from return address"); + return UNWIND_X86_MODE_DWARF; + } + registers[(cfaOffsetEBP+28)/4] = UNWIND_X86_REG_EBP; + } + + // validate that saved registers are contiguous and abut return address on stack + for (int i=0; i < saveRegisterCount; ++i) { + if ( registers[5-i] == 0 ) { + strcpy(warningBuffer, "registers not save contiguously in stack"); + return UNWIND_X86_MODE_DWARF; + } + } + + // encode register permutation + // the 10-bits are encoded differently depending on the number of registers saved + int renumregs[6]; + for (int i=6-saveRegisterCount; i < 6; ++i) { + int countless = 0; + for (int j=6-saveRegisterCount; j < i; ++j) { + if ( registers[j] < registers[i] ) + ++countless; + } + renumregs[i] = registers[i] - countless -1; + } + uint32_t permutationEncoding = 0; + switch ( saveRegisterCount ) { + case 6: + permutationEncoding |= (120*renumregs[0] + 24*renumregs[1] + 6*renumregs[2] + 2*renumregs[3] + renumregs[4]); + break; + case 5: + permutationEncoding |= (120*renumregs[1] + 24*renumregs[2] + 6*renumregs[3] + 2*renumregs[4] + renumregs[5]); + break; + case 4: + permutationEncoding |= (60*renumregs[2] + 12*renumregs[3] + 3*renumregs[4] + renumregs[5]); + break; + case 3: + permutationEncoding |= (20*renumregs[3] + 4*renumregs[4] + renumregs[5]); + break; + case 2: + permutationEncoding |= (5*renumregs[4] + renumregs[5]); + break; + case 1: + permutationEncoding |= (renumregs[5]); + break; + } + + encoding |= (stackValue << __builtin_ctz(UNWIND_X86_FRAMELESS_STACK_SIZE)); + encoding |= (stackAdjust << __builtin_ctz(UNWIND_X86_FRAMELESS_STACK_ADJUST)); + encoding |= (saveRegisterCount << __builtin_ctz(UNWIND_X86_FRAMELESS_STACK_REG_COUNT)); + encoding |= (permutationEncoding << __builtin_ctz(UNWIND_X86_FRAMELESS_STACK_REG_PERMUTATION)); + return encoding; + } +} + + + + + + + +// +// ppc specific functions +// +template <typename A, typename R> +int DwarfInstructions<A,R>::lastRestoreReg(const Registers_ppc&) +{ + COMPILE_TIME_ASSERT( (int)CFI_Parser<A>::kMaxRegisterNumber > (int)UNW_PPC_SPEFSCR ); + return UNW_PPC_SPEFSCR; +} + +template <typename A, typename R> +bool DwarfInstructions<A,R>::isReturnAddressRegister(int regNum, const Registers_ppc&) +{ + return (regNum == UNW_PPC_LR); +} + +template <typename A, typename R> +typename A::pint_t DwarfInstructions<A,R>::getCFA(A& addressSpace, const typename CFI_Parser<A>::PrologInfo& prolog, + const Registers_ppc& registers) +{ + if ( prolog.cfaRegister != 0 ) + return registers.getRegister(prolog.cfaRegister) + prolog.cfaRegisterOffset; + else if ( prolog.cfaExpression != 0 ) + return evaluateExpression(prolog.cfaExpression, addressSpace, registers, 0); + else + ABORT("getCFA(): unknown location for ppc cfa"); +} + + +template <typename A, typename R> +compact_unwind_encoding_t DwarfInstructions<A,R>::encodeToUseDwarf(const Registers_ppc&) +{ + return UNWIND_X86_MODE_DWARF; +} + + +template <typename A, typename R> +compact_unwind_encoding_t DwarfInstructions<A,R>::createCompactEncodingFromProlog(A& addressSpace, pint_t funcAddr, + const Registers_ppc& r, const typename CFI_Parser<A>::PrologInfo& prolog, + char warningBuffer[1024]) +{ + warningBuffer[0] = '\0'; + return UNWIND_X86_MODE_DWARF; +} + + + + +} // namespace lldb_private + + +#endif // __DWARF_INSTRUCTIONS_HPP__ + + + + |
