| //===--- ARMEHABIPrinter.h - ARM EHABI Unwind Information Printer ----------===// |
| // |
| // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
| // See https://llvm.org/LICENSE.txt for license information. |
| // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #ifndef LLVM_TOOLS_LLVM_READOBJ_ARMEHABIPRINTER_H |
| #define LLVM_TOOLS_LLVM_READOBJ_ARMEHABIPRINTER_H |
| |
| #include "llvm-readobj.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/ScopedPrinter.h" |
| #include "llvm/Support/type_traits.h" |
| |
| namespace llvm { |
| namespace ARM { |
| namespace EHABI { |
| |
| class OpcodeDecoder { |
| ScopedPrinter &SW; |
| raw_ostream &OS; |
| |
| struct RingEntry { |
| uint8_t Mask; |
| uint8_t Value; |
| void (OpcodeDecoder::*Routine)(const uint8_t *Opcodes, unsigned &OI); |
| }; |
| static ArrayRef<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(ScopedPrinter &SW) : SW(SW), OS(SW.getOStream()) {} |
| void Decode(const uint8_t *Opcodes, off_t Offset, size_t Length); |
| }; |
| |
| inline ArrayRef<OpcodeDecoder::RingEntry> OpcodeDecoder::ring() { |
| static const OpcodeDecoder::RingEntry 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}, |
| }; |
| return ArrayRef(Ring); |
| } |
| |
| inline 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); |
| } |
| inline 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); |
| } |
| inline 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'; |
| } |
| inline 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); |
| } |
| inline 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); |
| } |
| inline 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)); |
| } |
| inline 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'; |
| } |
| inline 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'; |
| } |
| inline void OpcodeDecoder::Decode_10110000(const uint8_t *Opcodes, |
| unsigned &OI) { |
| uint8_t Opcode = Opcodes[OI++ ^ 3]; |
| SW.startLine() << format("0x%02X ; finish\n", Opcode); |
| } |
| inline 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) ? "spare" : "pop "); |
| if (((Opcode1 & 0xf0) == 0x00) && Opcode1) |
| PrintGPR((Opcode1 & 0x0f)); |
| OS << '\n'; |
| } |
| inline 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)); |
| } |
| inline 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'; |
| } |
| inline void OpcodeDecoder::Decode_101101nn(const uint8_t *Opcodes, |
| unsigned &OI) { |
| uint8_t Opcode = Opcodes[OI++ ^ 3]; |
| SW.startLine() << format("0x%02X ; %s\n", Opcode, |
| (Opcode == 0xb4) ? "pop ra_auth_code" : "spare"); |
| } |
| inline 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'; |
| } |
| inline 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'; |
| } |
| inline 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'; |
| } |
| inline 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'; |
| } |
| inline 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'; |
| } |
| inline void OpcodeDecoder::Decode_11001yyy(const uint8_t *Opcodes, |
| unsigned &OI) { |
| uint8_t Opcode = Opcodes[OI++ ^ 3]; |
| SW.startLine() << format("0x%02X ; spare\n", Opcode); |
| } |
| inline 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'; |
| } |
| inline 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'; |
| } |
| inline void OpcodeDecoder::Decode_11xxxyyy(const uint8_t *Opcodes, |
| unsigned &OI) { |
| uint8_t Opcode = Opcodes[OI++ ^ 3]; |
| SW.startLine() << format("0x%02X ; spare\n", Opcode); |
| } |
| |
| inline 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 << '}'; |
| } |
| |
| inline 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 << '}'; |
| } |
| |
| inline void OpcodeDecoder::Decode(const uint8_t *Opcodes, off_t Offset, |
| size_t Length) { |
| for (unsigned OCI = Offset; OCI < Length + Offset; ) { |
| bool Decoded = false; |
| for (const auto &RE : ring()) { |
| if ((Opcodes[OCI ^ 3] & RE.Mask) == RE.Value) { |
| (this->*RE.Routine)(Opcodes, OCI); |
| Decoded = true; |
| break; |
| } |
| } |
| if (!Decoded) |
| SW.startLine() << format("0x%02X ; reserved\n", Opcodes[OCI++ ^ 3]); |
| } |
| } |
| |
| template <typename ET> |
| class PrinterContext { |
| typedef typename ET::Sym Elf_Sym; |
| typedef typename ET::Shdr Elf_Shdr; |
| typedef typename ET::Rel Elf_Rel; |
| typedef typename ET::Word Elf_Word; |
| |
| ScopedPrinter &SW; |
| const object::ELFFile<ET> &ELF; |
| StringRef FileName; |
| const Elf_Shdr *Symtab; |
| ArrayRef<Elf_Word> ShndxTable; |
| |
| static const size_t IndexTableEntrySize; |
| |
| static uint64_t PREL31(uint32_t Address, uint32_t Place) { |
| uint64_t Location = Address & 0x7fffffff; |
| if (Location & 0x40000000) |
| Location |= (uint64_t) ~0x7fffffff; |
| return Location + Place; |
| } |
| |
| ErrorOr<StringRef> |
| FunctionAtAddress(uint64_t Address, |
| std::optional<unsigned> SectionIndex) 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 &EHT, |
| uint64_t TableEntryOffset) const; |
| void PrintOpcodes(const uint8_t *Entry, size_t Length, off_t Offset) const; |
| |
| public: |
| PrinterContext(ScopedPrinter &SW, const object::ELFFile<ET> &ELF, |
| StringRef FileName, const Elf_Shdr *Symtab) |
| : SW(SW), ELF(ELF), FileName(FileName), Symtab(Symtab) {} |
| |
| void PrintUnwindInformation() const; |
| }; |
| |
| template <typename ET> |
| const size_t PrinterContext<ET>::IndexTableEntrySize = 8; |
| |
| template <typename ET> |
| ErrorOr<StringRef> PrinterContext<ET>::FunctionAtAddress( |
| uint64_t Address, std::optional<unsigned> SectionIndex) const { |
| if (!Symtab) |
| return inconvertibleErrorCode(); |
| auto StrTableOrErr = ELF.getStringTableForSymtab(*Symtab); |
| if (!StrTableOrErr) |
| reportError(StrTableOrErr.takeError(), FileName); |
| StringRef StrTable = *StrTableOrErr; |
| |
| for (const Elf_Sym &Sym : unwrapOrError(FileName, ELF.symbols(Symtab))) { |
| if (SectionIndex && *SectionIndex != Sym.st_shndx) |
| continue; |
| |
| if (Sym.st_value == Address && Sym.getType() == ELF::STT_FUNC) { |
| auto NameOrErr = Sym.getName(StrTable); |
| if (!NameOrErr) { |
| // TODO: Actually report errors helpfully. |
| consumeError(NameOrErr.takeError()); |
| return inconvertibleErrorCode(); |
| } |
| return *NameOrErr; |
| } |
| } |
| |
| return inconvertibleErrorCode(); |
| } |
| |
| template <typename ET> |
| const typename ET::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 (const Elf_Shdr &Sec : unwrapOrError(FileName, ELF.sections())) { |
| if (Sec.sh_type != ELF::SHT_REL || Sec.sh_info != IndexSectionIndex) |
| continue; |
| |
| auto SymTabOrErr = ELF.getSection(Sec.sh_link); |
| if (!SymTabOrErr) |
| reportError(SymTabOrErr.takeError(), FileName); |
| const Elf_Shdr *SymTab = *SymTabOrErr; |
| |
| for (const Elf_Rel &R : unwrapOrError(FileName, ELF.rels(Sec))) { |
| if (R.r_offset != static_cast<unsigned>(IndexTableOffset)) |
| continue; |
| |
| typename ET::Rela RelA; |
| RelA.r_offset = R.r_offset; |
| RelA.r_info = R.r_info; |
| RelA.r_addend = 0; |
| |
| const Elf_Sym *Symbol = |
| unwrapOrError(FileName, ELF.getRelocationSymbol(RelA, SymTab)); |
| |
| auto Ret = ELF.getSection(*Symbol, SymTab, ShndxTable); |
| if (!Ret) |
| report_fatal_error(Twine(errorToErrorCode(Ret.takeError()).message())); |
| return *Ret; |
| } |
| } |
| return nullptr; |
| } |
| |
| template <typename ET> |
| static const typename ET::Shdr * |
| findSectionContainingAddress(const object::ELFFile<ET> &Obj, StringRef FileName, |
| uint64_t Address) { |
| for (const typename ET::Shdr &Sec : unwrapOrError(FileName, Obj.sections())) |
| if (Address >= Sec.sh_addr && Address < Sec.sh_addr + Sec.sh_size) |
| return &Sec; |
| return nullptr; |
| } |
| |
| template <typename ET> |
| void PrinterContext<ET>::PrintExceptionTable(const Elf_Shdr &EHT, |
| uint64_t TableEntryOffset) const { |
| // TODO: handle failure. |
| Expected<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")); |
| const bool IsRelocatable = ELF.getHeader().e_type == ELF::ET_REL; |
| uint64_t Address = IsRelocatable |
| ? PREL31(Word, EHT.sh_addr) |
| : PREL31(Word, EHT.sh_addr + TableEntryOffset); |
| SW.printHex("PersonalityRoutineAddress", Address); |
| std::optional<unsigned> SecIndex = |
| IsRelocatable ? std::optional<unsigned>(EHT.sh_link) : std::nullopt; |
| if (ErrorOr<StringRef> Name = FunctionAtAddress(Address, SecIndex)) |
| 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(SW).Decode(Entry, Offset, Length); |
| } |
| |
| template <typename ET> |
| void PrinterContext<ET>::PrintIndexTable(unsigned SectionIndex, |
| const Elf_Shdr *IT) const { |
| // TODO: handle failure. |
| Expected<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; |
| const bool IsRelocatable = ELF.getHeader().e_type == ELF::ET_REL; |
| |
| 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; |
| } |
| |
| // FIXME: For a relocatable object ideally we might want to: |
| // 1) Find a relocation for the offset of Word0. |
| // 2) Verify this relocation is of an expected type (R_ARM_PREL31) and |
| // verify the symbol index. |
| // 3) Resolve the relocation using it's symbol value, addend etc. |
| // Currently the code assumes that Word0 contains an addend of a |
| // R_ARM_PREL31 REL relocation that references a section symbol. RELA |
| // relocations are not supported and it works because addresses of sections |
| // are nulls in relocatable objects. |
| // |
| // For a non-relocatable object, Word0 contains a place-relative signed |
| // offset to the referenced entity. |
| const uint64_t Address = |
| IsRelocatable |
| ? PREL31(Word0, IT->sh_addr) |
| : PREL31(Word0, IT->sh_addr + Entry * IndexTableEntrySize); |
| SW.printHex("FunctionAddress", Address); |
| |
| // In a relocatable output we might have many .ARM.exidx sections linked to |
| // their code sections via the sh_link field. For a non-relocatable ELF file |
| // the sh_link field is not reliable, because we have one .ARM.exidx section |
| // normally, but might have many code sections. |
| std::optional<unsigned> SecIndex = |
| IsRelocatable ? std::optional<unsigned>(IT->sh_link) : std::nullopt; |
| if (ErrorOr<StringRef> Name = FunctionAtAddress(Address, SecIndex)) |
| 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; |
| uint64_t TableEntryAddress; |
| if (IsRelocatable) { |
| TableEntryAddress = PREL31(Word1, IT->sh_addr); |
| EHT = FindExceptionTable(SectionIndex, Entry * IndexTableEntrySize + 4); |
| } else { |
| TableEntryAddress = |
| PREL31(Word1, IT->sh_addr + Entry * IndexTableEntrySize + 4); |
| EHT = findSectionContainingAddress(ELF, FileName, TableEntryAddress); |
| } |
| |
| if (EHT) |
| // TODO: handle failure. |
| if (Expected<StringRef> Name = ELF.getSectionName(*EHT)) |
| SW.printString("ExceptionHandlingTable", *Name); |
| |
| SW.printHex(IsRelocatable ? "TableEntryOffset" : "TableEntryAddress", |
| TableEntryAddress); |
| if (EHT) { |
| if (IsRelocatable) |
| PrintExceptionTable(*EHT, TableEntryAddress); |
| else |
| PrintExceptionTable(*EHT, TableEntryAddress - EHT->sh_addr); |
| } |
| } |
| } |
| } |
| |
| template <typename ET> |
| void PrinterContext<ET>::PrintUnwindInformation() const { |
| DictScope UI(SW, "UnwindInformation"); |
| |
| int SectionIndex = 0; |
| for (const Elf_Shdr &Sec : unwrapOrError(FileName, ELF.sections())) { |
| if (Sec.sh_type == ELF::SHT_ARM_EXIDX) { |
| DictScope UIT(SW, "UnwindIndexTable"); |
| |
| SW.printNumber("SectionIndex", SectionIndex); |
| // TODO: handle failure. |
| if (Expected<StringRef> SectionName = ELF.getSectionName(Sec)) |
| SW.printString("SectionName", *SectionName); |
| SW.printHex("SectionOffset", Sec.sh_offset); |
| |
| PrintIndexTable(SectionIndex, &Sec); |
| } |
| ++SectionIndex; |
| } |
| } |
| } |
| } |
| } |
| |
| #endif |
