//===--- ARMEHABIPrinter.h - ARM EHABI Unwind Information Printer ----------===// // // The LLVM Compiler Infrastructure // // This file is distributed under the University of Illinois Open Source // License. See LICENSE.TXT for details. // //===----------------------------------------------------------------------===// #ifndef LLVM_TOOLS_LLVM_READOBJ_ARMEHABIPRINTER_H #define LLVM_TOOLS_LLVM_READOBJ_ARMEHABIPRINTER_H #include "Error.h" #include "StreamWriter.h" #include "llvm/ADT/STLExtras.h" #include "llvm/Object/ELF.h" #include "llvm/Object/ELFTypes.h" #include "llvm/Support/ARMEHABI.h" #include "llvm/Support/Debug.h" #include "llvm/Support/Endian.h" #include "llvm/Support/Format.h" #include "llvm/Support/type_traits.h" namespace llvm { namespace ARM { namespace EHABI { class OpcodeDecoder { StreamWriter &SW; raw_ostream &OS; struct RingEntry { uint8_t Mask; uint8_t Value; void (OpcodeDecoder::*Routine)(const uint8_t *Opcodes, unsigned &OI); }; static const RingEntry Ring[]; void Decode_00xxxxxx(const uint8_t *Opcodes, unsigned &OI); void Decode_01xxxxxx(const uint8_t *Opcodes, unsigned &OI); void Decode_1000iiii_iiiiiiii(const uint8_t *Opcodes, unsigned &OI); void Decode_10011101(const uint8_t *Opcodes, unsigned &OI); void Decode_10011111(const uint8_t *Opcodes, unsigned &OI); void Decode_1001nnnn(const uint8_t *Opcodes, unsigned &OI); void Decode_10100nnn(const uint8_t *Opcodes, unsigned &OI); void Decode_10101nnn(const uint8_t *Opcodes, unsigned &OI); void Decode_10110000(const uint8_t *Opcodes, unsigned &OI); void Decode_10110001_0000iiii(const uint8_t *Opcodes, unsigned &OI); void Decode_10110010_uleb128(const uint8_t *Opcodes, unsigned &OI); void Decode_10110011_sssscccc(const uint8_t *Opcodes, unsigned &OI); void Decode_101101nn(const uint8_t *Opcodes, unsigned &OI); void Decode_10111nnn(const uint8_t *Opcodes, unsigned &OI); void Decode_11000110_sssscccc(const uint8_t *Opcodes, unsigned &OI); void Decode_11000111_0000iiii(const uint8_t *Opcodes, unsigned &OI); void Decode_11001000_sssscccc(const uint8_t *Opcodes, unsigned &OI); void Decode_11001001_sssscccc(const uint8_t *Opcodes, unsigned &OI); void Decode_11001yyy(const uint8_t *Opcodes, unsigned &OI); void Decode_11000nnn(const uint8_t *Opcodes, unsigned &OI); void Decode_11010nnn(const uint8_t *Opcodes, unsigned &OI); void Decode_11xxxyyy(const uint8_t *Opcodes, unsigned &OI); void PrintGPR(uint16_t GPRMask); void PrintRegisters(uint32_t Mask, StringRef Prefix); public: OpcodeDecoder(StreamWriter &SW) : SW(SW), OS(SW.getOStream()) {} void Decode(const uint8_t *Opcodes, off_t Offset, size_t Length); }; const OpcodeDecoder::RingEntry OpcodeDecoder::Ring[] = { { 0xc0, 0x00, &OpcodeDecoder::Decode_00xxxxxx }, { 0xc0, 0x40, &OpcodeDecoder::Decode_01xxxxxx }, { 0xf0, 0x80, &OpcodeDecoder::Decode_1000iiii_iiiiiiii }, { 0xff, 0x9d, &OpcodeDecoder::Decode_10011101 }, { 0xff, 0x9f, &OpcodeDecoder::Decode_10011111 }, { 0xf0, 0x90, &OpcodeDecoder::Decode_1001nnnn }, { 0xf8, 0xa0, &OpcodeDecoder::Decode_10100nnn }, { 0xf8, 0xa8, &OpcodeDecoder::Decode_10101nnn }, { 0xff, 0xb0, &OpcodeDecoder::Decode_10110000 }, { 0xff, 0xb1, &OpcodeDecoder::Decode_10110001_0000iiii }, { 0xff, 0xb2, &OpcodeDecoder::Decode_10110010_uleb128 }, { 0xff, 0xb3, &OpcodeDecoder::Decode_10110011_sssscccc }, { 0xfc, 0xb4, &OpcodeDecoder::Decode_101101nn }, { 0xf8, 0xb8, &OpcodeDecoder::Decode_10111nnn }, { 0xff, 0xc6, &OpcodeDecoder::Decode_11000110_sssscccc }, { 0xff, 0xc7, &OpcodeDecoder::Decode_11000111_0000iiii }, { 0xff, 0xc8, &OpcodeDecoder::Decode_11001000_sssscccc }, { 0xff, 0xc9, &OpcodeDecoder::Decode_11001001_sssscccc }, { 0xc8, 0xc8, &OpcodeDecoder::Decode_11001yyy }, { 0xf8, 0xc0, &OpcodeDecoder::Decode_11000nnn }, { 0xf8, 0xd0, &OpcodeDecoder::Decode_11010nnn }, { 0xc0, 0xc0, &OpcodeDecoder::Decode_11xxxyyy }, }; void OpcodeDecoder::Decode_00xxxxxx(const uint8_t *Opcodes, unsigned &OI) { uint8_t Opcode = Opcodes[OI++ ^ 3]; SW.startLine() << format("0x%02X ; vsp = vsp + %u\n", Opcode, ((Opcode & 0x3f) << 2) + 4); } void OpcodeDecoder::Decode_01xxxxxx(const uint8_t *Opcodes, unsigned &OI) { uint8_t Opcode = Opcodes[OI++ ^ 3]; SW.startLine() << format("0x%02X ; vsp = vsp - %u\n", Opcode, ((Opcode & 0x3f) << 2) + 4); } void OpcodeDecoder::Decode_1000iiii_iiiiiiii(const uint8_t *Opcodes, unsigned &OI) { uint8_t Opcode0 = Opcodes[OI++ ^ 3]; uint8_t Opcode1 = Opcodes[OI++ ^ 3]; uint16_t GPRMask = (Opcode1 << 4) | ((Opcode0 & 0x0f) << 12); SW.startLine() << format("0x%02X 0x%02X ; %s", Opcode0, Opcode1, GPRMask ? "pop " : "refuse to unwind"); if (GPRMask) PrintGPR(GPRMask); OS << '\n'; } void OpcodeDecoder::Decode_10011101(const uint8_t *Opcodes, unsigned &OI) { uint8_t Opcode = Opcodes[OI++ ^ 3]; SW.startLine() << format("0x%02X ; reserved (ARM MOVrr)\n", Opcode); } void OpcodeDecoder::Decode_10011111(const uint8_t *Opcodes, unsigned &OI) { uint8_t Opcode = Opcodes[OI++ ^ 3]; SW.startLine() << format("0x%02X ; reserved (WiMMX MOVrr)\n", Opcode); } void OpcodeDecoder::Decode_1001nnnn(const uint8_t *Opcodes, unsigned &OI) { uint8_t Opcode = Opcodes[OI++ ^ 3]; SW.startLine() << format("0x%02X ; vsp = r%u\n", Opcode, (Opcode & 0x0f)); } void OpcodeDecoder::Decode_10100nnn(const uint8_t *Opcodes, unsigned &OI) { uint8_t Opcode = Opcodes[OI++ ^ 3]; SW.startLine() << format("0x%02X ; pop ", Opcode); PrintGPR((((1 << ((Opcode & 0x7) + 1)) - 1) << 4)); OS << '\n'; } void OpcodeDecoder::Decode_10101nnn(const uint8_t *Opcodes, unsigned &OI) { uint8_t Opcode = Opcodes[OI++ ^ 3]; SW.startLine() << format("0x%02X ; pop ", Opcode); PrintGPR((((1 << ((Opcode & 0x7) + 1)) - 1) << 4) | (1 << 14)); OS << '\n'; } void OpcodeDecoder::Decode_10110000(const uint8_t *Opcodes, unsigned &OI) { uint8_t Opcode = Opcodes[OI++ ^ 3]; SW.startLine() << format("0x%02X ; finish\n", Opcode); } void OpcodeDecoder::Decode_10110001_0000iiii(const uint8_t *Opcodes, unsigned &OI) { uint8_t Opcode0 = Opcodes[OI++ ^ 3]; uint8_t Opcode1 = Opcodes[OI++ ^ 3]; SW.startLine() << format("0x%02X 0x%02X ; %s", Opcode0, Opcode1, ((Opcode1 & 0xf0) || Opcode1 == 0x00) ? "spare" : "pop "); if (((Opcode1 & 0xf0) == 0x00) && Opcode1) PrintGPR((Opcode1 & 0x0f)); OS << '\n'; } void OpcodeDecoder::Decode_10110010_uleb128(const uint8_t *Opcodes, unsigned &OI) { uint8_t Opcode = Opcodes[OI++ ^ 3]; SW.startLine() << format("0x%02X ", Opcode); SmallVector<uint8_t, 4> ULEB; do { ULEB.push_back(Opcodes[OI ^ 3]); } while (Opcodes[OI++ ^ 3] & 0x80); for (unsigned BI = 0, BE = ULEB.size(); BI != BE; ++BI) OS << format("0x%02X ", ULEB[BI]); uint64_t Value = 0; for (unsigned BI = 0, BE = ULEB.size(); BI != BE; ++BI) Value = Value | ((ULEB[BI] & 0x7f) << (7 * BI)); OS << format("; vsp = vsp + %" PRIu64 "\n", 0x204 + (Value << 2)); } void OpcodeDecoder::Decode_10110011_sssscccc(const uint8_t *Opcodes, unsigned &OI) { uint8_t Opcode0 = Opcodes[OI++ ^ 3]; uint8_t Opcode1 = Opcodes[OI++ ^ 3]; SW.startLine() << format("0x%02X 0x%02X ; pop ", Opcode0, Opcode1); uint8_t Start = ((Opcode1 & 0xf0) >> 4); uint8_t Count = ((Opcode1 & 0x0f) >> 0); PrintRegisters((((1 << (Count + 1)) - 1) << Start), "d"); OS << '\n'; } void OpcodeDecoder::Decode_101101nn(const uint8_t *Opcodes, unsigned &OI) { uint8_t Opcode = Opcodes[OI++ ^ 3]; SW.startLine() << format("0x%02X ; spare\n", Opcode); } void OpcodeDecoder::Decode_10111nnn(const uint8_t *Opcodes, unsigned &OI) { uint8_t Opcode = Opcodes[OI++ ^ 3]; SW.startLine() << format("0x%02X ; pop ", Opcode); PrintRegisters((((1 << ((Opcode & 0x07) + 1)) - 1) << 8), "d"); OS << '\n'; } void OpcodeDecoder::Decode_11000110_sssscccc(const uint8_t *Opcodes, unsigned &OI) { uint8_t Opcode0 = Opcodes[OI++ ^ 3]; uint8_t Opcode1 = Opcodes[OI++ ^ 3]; SW.startLine() << format("0x%02X 0x%02X ; pop ", Opcode0, Opcode1); uint8_t Start = ((Opcode1 & 0xf0) >> 4); uint8_t Count = ((Opcode1 & 0x0f) >> 0); PrintRegisters((((1 << (Count + 1)) - 1) << Start), "wR"); OS << '\n'; } void OpcodeDecoder::Decode_11000111_0000iiii(const uint8_t *Opcodes, unsigned &OI) { uint8_t Opcode0 = Opcodes[OI++ ^ 3]; uint8_t Opcode1 = Opcodes[OI++ ^ 3]; SW.startLine() << format("0x%02X 0x%02X ; %s", Opcode0, Opcode1, ((Opcode1 & 0xf0) || Opcode1 == 0x00) ? "spare" : "pop "); if ((Opcode1 & 0xf0) == 0x00 && Opcode1) PrintRegisters(Opcode1 & 0x0f, "wCGR"); OS << '\n'; } void OpcodeDecoder::Decode_11001000_sssscccc(const uint8_t *Opcodes, unsigned &OI) { uint8_t Opcode0 = Opcodes[OI++ ^ 3]; uint8_t Opcode1 = Opcodes[OI++ ^ 3]; SW.startLine() << format("0x%02X 0x%02X ; pop ", Opcode0, Opcode1); uint8_t Start = 16 + ((Opcode1 & 0xf0) >> 4); uint8_t Count = ((Opcode1 & 0x0f) >> 0); PrintRegisters((((1 << (Count + 1)) - 1) << Start), "d"); OS << '\n'; } void OpcodeDecoder::Decode_11001001_sssscccc(const uint8_t *Opcodes, unsigned &OI) { uint8_t Opcode0 = Opcodes[OI++ ^ 3]; uint8_t Opcode1 = Opcodes[OI++ ^ 3]; SW.startLine() << format("0x%02X 0x%02X ; pop ", Opcode0, Opcode1); uint8_t Start = ((Opcode1 & 0xf0) >> 4); uint8_t Count = ((Opcode1 & 0x0f) >> 0); PrintRegisters((((1 << (Count + 1)) - 1) << Start), "d"); OS << '\n'; } void OpcodeDecoder::Decode_11001yyy(const uint8_t *Opcodes, unsigned &OI) { uint8_t Opcode = Opcodes[OI++ ^ 3]; SW.startLine() << format("0x%02X ; spare\n", Opcode); } void OpcodeDecoder::Decode_11000nnn(const uint8_t *Opcodes, unsigned &OI) { uint8_t Opcode = Opcodes[OI++ ^ 3]; SW.startLine() << format("0x%02X ; pop ", Opcode); PrintRegisters((((1 << ((Opcode & 0x07) + 1)) - 1) << 10), "wR"); OS << '\n'; } void OpcodeDecoder::Decode_11010nnn(const uint8_t *Opcodes, unsigned &OI) { uint8_t Opcode = Opcodes[OI++ ^ 3]; SW.startLine() << format("0x%02X ; pop ", Opcode); PrintRegisters((((1 << ((Opcode & 0x07) + 1)) - 1) << 8), "d"); OS << '\n'; } void OpcodeDecoder::Decode_11xxxyyy(const uint8_t *Opcodes, unsigned &OI) { uint8_t Opcode = Opcodes[OI++ ^ 3]; SW.startLine() << format("0x%02X ; spare\n", Opcode); } void OpcodeDecoder::PrintGPR(uint16_t GPRMask) { static const char *GPRRegisterNames[16] = { "r0", "r1", "r2", "r3", "r4", "r5", "r6", "r7", "r8", "r9", "r10", "fp", "ip", "sp", "lr", "pc" }; OS << '{'; bool Comma = false; for (unsigned RI = 0, RE = 17; RI < RE; ++RI) { if (GPRMask & (1 << RI)) { if (Comma) OS << ", "; OS << GPRRegisterNames[RI]; Comma = true; } } OS << '}'; } void OpcodeDecoder::PrintRegisters(uint32_t VFPMask, StringRef Prefix) { OS << '{'; bool Comma = false; for (unsigned RI = 0, RE = 32; RI < RE; ++RI) { if (VFPMask & (1 << RI)) { if (Comma) OS << ", "; OS << Prefix << RI; Comma = true; } } OS << '}'; } void OpcodeDecoder::Decode(const uint8_t *Opcodes, off_t Offset, size_t Length) { for (unsigned OCI = Offset; OCI < Length + Offset; ) { bool Decoded = false; for (unsigned REI = 0, REE = array_lengthof(Ring); REI != REE && !Decoded; ++REI) { if ((Opcodes[OCI ^ 3] & Ring[REI].Mask) == Ring[REI].Value) { (this->*Ring[REI].Routine)(Opcodes, OCI); Decoded = true; break; } } if (!Decoded) SW.startLine() << format("0x%02X ; reserved\n", Opcodes[OCI++ ^ 3]); } } template <typename ET> class PrinterContext { StreamWriter &SW; const object::ELFFile<ET> *ELF; typedef typename object::ELFFile<ET>::Elf_Sym Elf_Sym; typedef typename object::ELFFile<ET>::Elf_Shdr Elf_Shdr; typedef typename object::ELFFile<ET>::Elf_Rel_Iter Elf_Rel_iterator; typedef typename object::ELFFile<ET>::Elf_Sym_Iter Elf_Sym_iterator; typedef typename object::ELFFile<ET>::Elf_Shdr_Iter Elf_Shdr_iterator; static const size_t IndexTableEntrySize; static uint64_t PREL31(uint32_t Address, uint32_t Place) { uint64_t Location = Address & 0x7fffffff; if (Location & 0x04000000) Location |= (uint64_t) ~0x7fffffff; return Location + Place; } ErrorOr<StringRef> FunctionAtAddress(unsigned Section, uint64_t Address) const; const Elf_Shdr *FindExceptionTable(unsigned IndexTableIndex, off_t IndexTableOffset) const; void PrintIndexTable(unsigned SectionIndex, const Elf_Shdr *IT) const; void PrintExceptionTable(const Elf_Shdr *IT, const Elf_Shdr *EHT, uint64_t TableEntryOffset) const; void PrintOpcodes(const uint8_t *Entry, size_t Length, off_t Offset) const; public: PrinterContext(StreamWriter &Writer, const object::ELFFile<ET> *File) : SW(Writer), ELF(File) {} void PrintUnwindInformation() const; }; template <typename ET> const size_t PrinterContext<ET>::IndexTableEntrySize = 8; template <typename ET> ErrorOr<StringRef> PrinterContext<ET>::FunctionAtAddress(unsigned Section, uint64_t Address) const { for (Elf_Sym_iterator SI = ELF->begin_symbols(), SE = ELF->end_symbols(); SI != SE; ++SI) if (SI->st_shndx == Section && SI->st_value == Address && SI->getType() == ELF::STT_FUNC) return ELF->getSymbolName(SI); return readobj_error::unknown_symbol; } template <typename ET> const typename object::ELFFile<ET>::Elf_Shdr * PrinterContext<ET>::FindExceptionTable(unsigned IndexSectionIndex, off_t IndexTableOffset) const { /// Iterate through the sections, searching for the relocation section /// associated with the unwind index table section specified by /// IndexSectionIndex. Iterate the associated section searching for the /// relocation associated with the index table entry specified by /// IndexTableOffset. The symbol is the section symbol for the exception /// handling table. Use this symbol to recover the actual exception handling /// table. for (Elf_Shdr_iterator SI = ELF->begin_sections(), SE = ELF->end_sections(); SI != SE; ++SI) { if (SI->sh_type == ELF::SHT_REL && SI->sh_info == IndexSectionIndex) { for (Elf_Rel_iterator RI = ELF->begin_rel(&*SI), RE = ELF->end_rel(&*SI); RI != RE; ++RI) { if (RI->r_offset == static_cast<unsigned>(IndexTableOffset)) { typename object::ELFFile<ET>::Elf_Rela RelA; RelA.r_offset = RI->r_offset; RelA.r_info = RI->r_info; RelA.r_addend = 0; std::pair<const Elf_Shdr *, const Elf_Sym *> Symbol = ELF->getRelocationSymbol(&(*SI), &RelA); return ELF->getSection(Symbol.second); } } } } return nullptr; } template <typename ET> void PrinterContext<ET>::PrintExceptionTable(const Elf_Shdr *IT, const Elf_Shdr *EHT, uint64_t TableEntryOffset) const { ErrorOr<ArrayRef<uint8_t> > Contents = ELF->getSectionContents(EHT); if (!Contents) return; /// ARM EHABI Section 6.2 - The generic model /// /// An exception-handling table entry for the generic model is laid out as: /// /// 3 3 /// 1 0 0 /// +-+------------------------------+ /// |0| personality routine offset | /// +-+------------------------------+ /// | personality routine data ... | /// /// /// ARM EHABI Section 6.3 - The ARM-defined compact model /// /// An exception-handling table entry for the compact model looks like: /// /// 3 3 2 2 2 2 /// 1 0 8 7 4 3 0 /// +-+---+----+-----------------------+ /// |1| 0 | Ix | data for pers routine | /// +-+---+----+-----------------------+ /// | more personality routine data | const support::ulittle32_t Word = *reinterpret_cast<const support::ulittle32_t *>(Contents->data() + TableEntryOffset); if (Word & 0x80000000) { SW.printString("Model", StringRef("Compact")); unsigned PersonalityIndex = (Word & 0x0f000000) >> 24; SW.printNumber("PersonalityIndex", PersonalityIndex); switch (PersonalityIndex) { case AEABI_UNWIND_CPP_PR0: PrintOpcodes(Contents->data() + TableEntryOffset, 3, 1); break; case AEABI_UNWIND_CPP_PR1: case AEABI_UNWIND_CPP_PR2: unsigned AdditionalWords = (Word & 0x00ff0000) >> 16; PrintOpcodes(Contents->data() + TableEntryOffset, 2 + 4 * AdditionalWords, 2); break; } } else { SW.printString("Model", StringRef("Generic")); uint64_t Address = PREL31(Word, EHT->sh_addr); SW.printHex("PersonalityRoutineAddress", Address); if (ErrorOr<StringRef> Name = FunctionAtAddress(EHT->sh_link, Address)) SW.printString("PersonalityRoutineName", *Name); } } template <typename ET> void PrinterContext<ET>::PrintOpcodes(const uint8_t *Entry, size_t Length, off_t Offset) const { ListScope OCC(SW, "Opcodes"); OpcodeDecoder(OCC.W).Decode(Entry, Offset, Length); } template <typename ET> void PrinterContext<ET>::PrintIndexTable(unsigned SectionIndex, const Elf_Shdr *IT) const { ErrorOr<ArrayRef<uint8_t> > Contents = ELF->getSectionContents(IT); if (!Contents) return; /// ARM EHABI Section 5 - Index Table Entries /// * The first word contains a PREL31 offset to the start of a function with /// bit 31 clear /// * The second word contains one of: /// - The PREL31 offset of the start of the table entry for the function, /// with bit 31 clear /// - The exception-handling table entry itself with bit 31 set /// - The special bit pattern EXIDX_CANTUNWIND, indicating that associated /// frames cannot be unwound const support::ulittle32_t *Data = reinterpret_cast<const support::ulittle32_t *>(Contents->data()); const unsigned Entries = IT->sh_size / IndexTableEntrySize; ListScope E(SW, "Entries"); for (unsigned Entry = 0; Entry < Entries; ++Entry) { DictScope E(SW, "Entry"); const support::ulittle32_t Word0 = Data[Entry * (IndexTableEntrySize / sizeof(*Data)) + 0]; const support::ulittle32_t Word1 = Data[Entry * (IndexTableEntrySize / sizeof(*Data)) + 1]; if (Word0 & 0x80000000) { errs() << "corrupt unwind data in section " << SectionIndex << "\n"; continue; } const uint64_t Offset = PREL31(Word0, IT->sh_addr); SW.printHex("FunctionAddress", Offset); if (ErrorOr<StringRef> Name = FunctionAtAddress(IT->sh_link, Offset)) SW.printString("FunctionName", *Name); if (Word1 == EXIDX_CANTUNWIND) { SW.printString("Model", StringRef("CantUnwind")); continue; } if (Word1 & 0x80000000) { SW.printString("Model", StringRef("Compact (Inline)")); unsigned PersonalityIndex = (Word1 & 0x0f000000) >> 24; SW.printNumber("PersonalityIndex", PersonalityIndex); PrintOpcodes(Contents->data() + Entry * IndexTableEntrySize + 4, 3, 1); } else { const Elf_Shdr *EHT = FindExceptionTable(SectionIndex, Entry * IndexTableEntrySize + 4); if (ErrorOr<StringRef> Name = ELF->getSectionName(EHT)) SW.printString("ExceptionHandlingTable", *Name); uint64_t TableEntryOffset = PREL31(Word1, IT->sh_addr); SW.printHex("TableEntryOffset", TableEntryOffset); PrintExceptionTable(IT, EHT, TableEntryOffset); } } } template <typename ET> void PrinterContext<ET>::PrintUnwindInformation() const { DictScope UI(SW, "UnwindInformation"); int SectionIndex = 0; for (Elf_Shdr_iterator SI = ELF->begin_sections(), SE = ELF->end_sections(); SI != SE; ++SI, ++SectionIndex) { if (SI->sh_type == ELF::SHT_ARM_EXIDX) { const Elf_Shdr *IT = &(*SI); DictScope UIT(SW, "UnwindIndexTable"); SW.printNumber("SectionIndex", SectionIndex); if (ErrorOr<StringRef> SectionName = ELF->getSectionName(IT)) SW.printString("SectionName", *SectionName); SW.printHex("SectionOffset", IT->sh_offset); PrintIndexTable(SectionIndex, IT); } } } } } } #endif