diff options
| -rw-r--r-- | lld/ELF/OutputSections.cpp | 55 |
1 files changed, 48 insertions, 7 deletions
diff --git a/lld/ELF/OutputSections.cpp b/lld/ELF/OutputSections.cpp index fba61963a82..2cec4e71bb8 100644 --- a/lld/ELF/OutputSections.cpp +++ b/lld/ELF/OutputSections.cpp @@ -881,6 +881,34 @@ static void skipLeb128(ArrayRef<uint8_t> &D) { fatal("corrupted or unsupported CIE information"); } +template <class ELFT> static size_t getAugPSize(unsigned Enc) { + switch (Enc & 0x0f) { + case dwarf::DW_EH_PE_absptr: + case dwarf::DW_EH_PE_signed: + return ELFT::Is64Bits ? 8 : 4; + case dwarf::DW_EH_PE_udata2: + case dwarf::DW_EH_PE_sdata2: + return 2; + case dwarf::DW_EH_PE_udata4: + case dwarf::DW_EH_PE_sdata4: + return 4; + case dwarf::DW_EH_PE_udata8: + case dwarf::DW_EH_PE_sdata8: + return 8; + } + fatal("unknown FDE encoding"); +} + +template <class ELFT> static void skipAugP(ArrayRef<uint8_t> &D) { + uint8_t Enc = readByte(D); + if ((Enc & 0xf0) == dwarf::DW_EH_PE_aligned) + fatal("DW_EH_PE_aligned encoding is not supported"); + size_t Size = getAugPSize<ELFT>(Enc); + if (Size < D.size()) + fatal("corrupted CIE"); + D = D.slice(Size); +} + template <class ELFT> uint8_t EHOutputSection<ELFT>::getFdeEncoding(ArrayRef<uint8_t> D) { if (D.size() < 8) @@ -911,13 +939,26 @@ uint8_t EHOutputSection<ELFT>::getFdeEncoding(ArrayRef<uint8_t> D) { else skipLeb128(D); - // We assume that the augmentation string always starts with 'z' - // (which specifies the size of the CIE field) and 'R' (which - // specifies the FDE encoding.) - if (!Aug.startswith("zR")) - fatal("unknown .eh_frame augmentation string: " + Aug); - skipLeb128(D); - return readByte(D); + // We only care about an 'R' value, but other records may precede an 'R' + // record. Records are not in TLV (type-length-value) format, so we need + // to teach the linker how to skip records for each type. + for (; !Aug.empty(); Aug = Aug.substr(1)) { + switch (Aug[0]) { + case 'z': + skipLeb128(D); + break; + case 'R': + return readByte(D); + case 'P': + skipAugP<ELFT>(D); + break; + case 'L': + break; + default: + fatal("unknown .eh_frame augmentation string: " + Aug); + } + } + return dwarf::DW_EH_PE_absptr; } template <class ELFT> |
