+ uint64_t Offset;
+ Check(RelI.getOffset(Offset));
+
+ DEBUG(dbgs() << "\t\tSectionID: " << SectionID
+ << " Offset: " << Offset
+ << "\n");
+ if (Arch == Triple::aarch64 &&
+ (RelType == ELF::R_AARCH64_CALL26 ||
+ RelType == ELF::R_AARCH64_JUMP26)) {
+ // This is an AArch64 branch relocation, need to use a stub function.
+ DEBUG(dbgs() << "\t\tThis is an AArch64 branch relocation.");
+ SectionEntry &Section = Sections[SectionID];
+
+ // Look for an existing stub.
+ StubMap::const_iterator i = Stubs.find(Value);
+ if (i != Stubs.end()) {
+ resolveRelocation(Section, Offset,
+ (uint64_t)Section.Address + i->second, RelType, 0);
+ DEBUG(dbgs() << " Stub function found\n");
+ } else {
+ // Create a new stub function.
+ DEBUG(dbgs() << " Create a new stub function\n");
+ Stubs[Value] = Section.StubOffset;
+ uint8_t *StubTargetAddr = createStubFunction(Section.Address +
+ Section.StubOffset);
+
+ RelocationEntry REmovz_g3(SectionID,
+ StubTargetAddr - Section.Address,
+ ELF::R_AARCH64_MOVW_UABS_G3, Value.Addend);
+ RelocationEntry REmovk_g2(SectionID,
+ StubTargetAddr - Section.Address + 4,
+ ELF::R_AARCH64_MOVW_UABS_G2_NC, Value.Addend);
+ RelocationEntry REmovk_g1(SectionID,
+ StubTargetAddr - Section.Address + 8,
+ ELF::R_AARCH64_MOVW_UABS_G1_NC, Value.Addend);
+ RelocationEntry REmovk_g0(SectionID,
+ StubTargetAddr - Section.Address + 12,
+ ELF::R_AARCH64_MOVW_UABS_G0_NC, Value.Addend);
+
+ if (Value.SymbolName) {
+ addRelocationForSymbol(REmovz_g3, Value.SymbolName);
+ addRelocationForSymbol(REmovk_g2, Value.SymbolName);
+ addRelocationForSymbol(REmovk_g1, Value.SymbolName);
+ addRelocationForSymbol(REmovk_g0, Value.SymbolName);
+ } else {
+ addRelocationForSection(REmovz_g3, Value.SectionID);
+ addRelocationForSection(REmovk_g2, Value.SectionID);
+ addRelocationForSection(REmovk_g1, Value.SectionID);
+ addRelocationForSection(REmovk_g0, Value.SectionID);
+ }
+ resolveRelocation(Section, Offset,
+ (uint64_t)Section.Address + Section.StubOffset,
+ RelType, 0);
+ Section.StubOffset += getMaxStubSize();
+ }
+ } else if (Arch == Triple::arm &&
+ (RelType == ELF::R_ARM_PC24 ||
+ RelType == ELF::R_ARM_CALL ||
+ RelType == ELF::R_ARM_JUMP24)) {
+ // This is an ARM branch relocation, need to use a stub function.
+ DEBUG(dbgs() << "\t\tThis is an ARM branch relocation.");
+ SectionEntry &Section = Sections[SectionID];
+
+ // Look for an existing stub.
+ StubMap::const_iterator i = Stubs.find(Value);
+ if (i != Stubs.end()) {
+ resolveRelocation(Section, Offset,
+ (uint64_t)Section.Address + i->second, RelType, 0);
+ DEBUG(dbgs() << " Stub function found\n");
+ } else {
+ // Create a new stub function.
+ DEBUG(dbgs() << " Create a new stub function\n");
+ Stubs[Value] = Section.StubOffset;
+ uint8_t *StubTargetAddr = createStubFunction(Section.Address +
+ Section.StubOffset);
+ RelocationEntry RE(SectionID, StubTargetAddr - Section.Address,
+ ELF::R_ARM_PRIVATE_0, Value.Addend);
+ if (Value.SymbolName)
+ addRelocationForSymbol(RE, Value.SymbolName);
+ else
+ addRelocationForSection(RE, Value.SectionID);
+
+ resolveRelocation(Section, Offset,
+ (uint64_t)Section.Address + Section.StubOffset,
+ RelType, 0);
+ Section.StubOffset += getMaxStubSize();
+ }
+ } else if ((Arch == Triple::mipsel || Arch == Triple::mips) &&
+ RelType == ELF::R_MIPS_26) {
+ // This is an Mips branch relocation, need to use a stub function.
+ DEBUG(dbgs() << "\t\tThis is a Mips branch relocation.");
+ SectionEntry &Section = Sections[SectionID];
+ uint8_t *Target = Section.Address + Offset;
+ uint32_t *TargetAddress = (uint32_t *)Target;
+
+ // Extract the addend from the instruction.
+ uint32_t Addend = ((*TargetAddress) & 0x03ffffff) << 2;
+
+ Value.Addend += Addend;
+
+ // Look up for existing stub.
+ StubMap::const_iterator i = Stubs.find(Value);
+ if (i != Stubs.end()) {
+ RelocationEntry RE(SectionID, Offset, RelType, i->second);
+ addRelocationForSection(RE, SectionID);
+ DEBUG(dbgs() << " Stub function found\n");
+ } else {
+ // Create a new stub function.
+ DEBUG(dbgs() << " Create a new stub function\n");
+ Stubs[Value] = Section.StubOffset;
+ uint8_t *StubTargetAddr = createStubFunction(Section.Address +
+ Section.StubOffset);
+
+ // Creating Hi and Lo relocations for the filled stub instructions.
+ RelocationEntry REHi(SectionID,
+ StubTargetAddr - Section.Address,
+ ELF::R_MIPS_UNUSED1, Value.Addend);
+ RelocationEntry RELo(SectionID,
+ StubTargetAddr - Section.Address + 4,
+ ELF::R_MIPS_UNUSED2, Value.Addend);
+
+ if (Value.SymbolName) {
+ addRelocationForSymbol(REHi, Value.SymbolName);
+ addRelocationForSymbol(RELo, Value.SymbolName);
+ } else {
+ addRelocationForSection(REHi, Value.SectionID);
+ addRelocationForSection(RELo, Value.SectionID);
+ }
+
+ RelocationEntry RE(SectionID, Offset, RelType, Section.StubOffset);
+ addRelocationForSection(RE, SectionID);
+ Section.StubOffset += getMaxStubSize();
+ }
+ } else if (Arch == Triple::ppc64 || Arch == Triple::ppc64le) {
+ if (RelType == ELF::R_PPC64_REL24) {
+ // A PPC branch relocation will need a stub function if the target is
+ // an external symbol (Symbol::ST_Unknown) or if the target address
+ // is not within the signed 24-bits branch address.
+ SectionEntry &Section = Sections[SectionID];
+ uint8_t *Target = Section.Address + Offset;
+ bool RangeOverflow = false;
+ if (SymType != SymbolRef::ST_Unknown) {
+ // A function call may points to the .opd entry, so the final symbol value
+ // in calculated based in the relocation values in .opd section.
+ findOPDEntrySection(Obj, ObjSectionToID, Value);
+ uint8_t *RelocTarget = Sections[Value.SectionID].Address + Value.Addend;
+ int32_t delta = static_cast<int32_t>(Target - RelocTarget);
+ // If it is within 24-bits branch range, just set the branch target
+ if (SignExtend32<24>(delta) == delta) {
+ RelocationEntry RE(SectionID, Offset, RelType, Value.Addend);
+ if (Value.SymbolName)
+ addRelocationForSymbol(RE, Value.SymbolName);
+ else
+ addRelocationForSection(RE, Value.SectionID);
+ } else {
+ RangeOverflow = true;
+ }
+ }
+ if (SymType == SymbolRef::ST_Unknown || RangeOverflow == true) {
+ // It is an external symbol (SymbolRef::ST_Unknown) or within a range
+ // larger than 24-bits.
+ StubMap::const_iterator i = Stubs.find(Value);
+ if (i != Stubs.end()) {
+ // Symbol function stub already created, just relocate to it
+ resolveRelocation(Section, Offset,
+ (uint64_t)Section.Address + i->second, RelType, 0);
+ DEBUG(dbgs() << " Stub function found\n");
+ } else {
+ // Create a new stub function.
+ DEBUG(dbgs() << " Create a new stub function\n");
+ Stubs[Value] = Section.StubOffset;
+ uint8_t *StubTargetAddr = createStubFunction(Section.Address +
+ Section.StubOffset);
+ RelocationEntry RE(SectionID, StubTargetAddr - Section.Address,
+ ELF::R_PPC64_ADDR64, Value.Addend);
+
+ // Generates the 64-bits address loads as exemplified in section
+ // 4.5.1 in PPC64 ELF ABI.
+ RelocationEntry REhst(SectionID,
+ StubTargetAddr - Section.Address + 2,
+ ELF::R_PPC64_ADDR16_HIGHEST, Value.Addend);
+ RelocationEntry REhr(SectionID,
+ StubTargetAddr - Section.Address + 6,
+ ELF::R_PPC64_ADDR16_HIGHER, Value.Addend);
+ RelocationEntry REh(SectionID,
+ StubTargetAddr - Section.Address + 14,
+ ELF::R_PPC64_ADDR16_HI, Value.Addend);
+ RelocationEntry REl(SectionID,
+ StubTargetAddr - Section.Address + 18,
+ ELF::R_PPC64_ADDR16_LO, Value.Addend);
+
+ if (Value.SymbolName) {
+ addRelocationForSymbol(REhst, Value.SymbolName);
+ addRelocationForSymbol(REhr, Value.SymbolName);
+ addRelocationForSymbol(REh, Value.SymbolName);
+ addRelocationForSymbol(REl, Value.SymbolName);
+ } else {
+ addRelocationForSection(REhst, Value.SectionID);
+ addRelocationForSection(REhr, Value.SectionID);
+ addRelocationForSection(REh, Value.SectionID);
+ addRelocationForSection(REl, Value.SectionID);
+ }
+
+ resolveRelocation(Section, Offset,
+ (uint64_t)Section.Address + Section.StubOffset,
+ RelType, 0);
+ if (SymType == SymbolRef::ST_Unknown)
+ // Restore the TOC for external calls
+ writeInt32BE(Target+4, 0xE8410028); // ld r2,40(r1)
+ Section.StubOffset += getMaxStubSize();
+ }
+ }
+ } else {
+ RelocationEntry RE(SectionID, Offset, RelType, Value.Addend);
+ // Extra check to avoid relocation againt empty symbols (usually
+ // the R_PPC64_TOC).
+ if (SymType != SymbolRef::ST_Unknown && TargetName.empty())
+ Value.SymbolName = NULL;
+
+ if (Value.SymbolName)
+ addRelocationForSymbol(RE, Value.SymbolName);
+ else
+ addRelocationForSection(RE, Value.SectionID);
+ }
+ } else if (Arch == Triple::systemz &&
+ (RelType == ELF::R_390_PLT32DBL ||
+ RelType == ELF::R_390_GOTENT)) {
+ // Create function stubs for both PLT and GOT references, regardless of
+ // whether the GOT reference is to data or code. The stub contains the
+ // full address of the symbol, as needed by GOT references, and the
+ // executable part only adds an overhead of 8 bytes.
+ //
+ // We could try to conserve space by allocating the code and data
+ // parts of the stub separately. However, as things stand, we allocate
+ // a stub for every relocation, so using a GOT in JIT code should be
+ // no less space efficient than using an explicit constant pool.
+ DEBUG(dbgs() << "\t\tThis is a SystemZ indirect relocation.");
+ SectionEntry &Section = Sections[SectionID];
+
+ // Look for an existing stub.
+ StubMap::const_iterator i = Stubs.find(Value);
+ uintptr_t StubAddress;
+ if (i != Stubs.end()) {
+ StubAddress = uintptr_t(Section.Address) + i->second;
+ DEBUG(dbgs() << " Stub function found\n");
+ } else {
+ // Create a new stub function.
+ DEBUG(dbgs() << " Create a new stub function\n");
+
+ uintptr_t BaseAddress = uintptr_t(Section.Address);
+ uintptr_t StubAlignment = getStubAlignment();
+ StubAddress = (BaseAddress + Section.StubOffset +
+ StubAlignment - 1) & -StubAlignment;
+ unsigned StubOffset = StubAddress - BaseAddress;
+
+ Stubs[Value] = StubOffset;
+ createStubFunction((uint8_t *)StubAddress);
+ RelocationEntry RE(SectionID, StubOffset + 8,
+ ELF::R_390_64, Value.Addend - Addend);
+ if (Value.SymbolName)
+ addRelocationForSymbol(RE, Value.SymbolName);
+ else
+ addRelocationForSection(RE, Value.SectionID);
+ Section.StubOffset = StubOffset + getMaxStubSize();
+ }
+
+ if (RelType == ELF::R_390_GOTENT)
+ resolveRelocation(Section, Offset, StubAddress + 8,
+ ELF::R_390_PC32DBL, Addend);
+ else
+ resolveRelocation(Section, Offset, StubAddress, RelType, Addend);
+ } else if (Arch == Triple::x86_64 && RelType == ELF::R_X86_64_PLT32) {
+ // The way the PLT relocations normally work is that the linker allocates the
+ // PLT and this relocation makes a PC-relative call into the PLT. The PLT
+ // entry will then jump to an address provided by the GOT. On first call, the
+ // GOT address will point back into PLT code that resolves the symbol. After
+ // the first call, the GOT entry points to the actual function.
+ //
+ // For local functions we're ignoring all of that here and just replacing
+ // the PLT32 relocation type with PC32, which will translate the relocation
+ // into a PC-relative call directly to the function. For external symbols we
+ // can't be sure the function will be within 2^32 bytes of the call site, so
+ // we need to create a stub, which calls into the GOT. This case is
+ // equivalent to the usual PLT implementation except that we use the stub
+ // mechanism in RuntimeDyld (which puts stubs at the end of the section)
+ // rather than allocating a PLT section.
+ if (Value.SymbolName) {
+ // This is a call to an external function.
+ // Look for an existing stub.
+ SectionEntry &Section = Sections[SectionID];
+ StubMap::const_iterator i = Stubs.find(Value);
+ uintptr_t StubAddress;
+ if (i != Stubs.end()) {
+ StubAddress = uintptr_t(Section.Address) + i->second;
+ DEBUG(dbgs() << " Stub function found\n");
+ } else {
+ // Create a new stub function (equivalent to a PLT entry).
+ DEBUG(dbgs() << " Create a new stub function\n");
+
+ uintptr_t BaseAddress = uintptr_t(Section.Address);
+ uintptr_t StubAlignment = getStubAlignment();
+ StubAddress = (BaseAddress + Section.StubOffset +
+ StubAlignment - 1) & -StubAlignment;
+ unsigned StubOffset = StubAddress - BaseAddress;
+ Stubs[Value] = StubOffset;
+ createStubFunction((uint8_t *)StubAddress);
+
+ // Create a GOT entry for the external function.
+ GOTEntries.push_back(Value);
+
+ // Make our stub function a relative call to the GOT entry.
+ RelocationEntry RE(SectionID, StubOffset + 2,
+ ELF::R_X86_64_GOTPCREL, -4);
+ addRelocationForSymbol(RE, Value.SymbolName);
+
+ // Bump our stub offset counter
+ Section.StubOffset = StubOffset + getMaxStubSize();
+ }
+
+ // Make the target call a call into the stub table.
+ resolveRelocation(Section, Offset, StubAddress,
+ ELF::R_X86_64_PC32, Addend);
+ } else {
+ RelocationEntry RE(SectionID, Offset, ELF::R_X86_64_PC32, Value.Addend,
+ Value.Offset);
+ addRelocationForSection(RE, Value.SectionID);
+ }
+ } else {
+ if (Arch == Triple::x86_64 && RelType == ELF::R_X86_64_GOTPCREL) {
+ GOTEntries.push_back(Value);
+ }
+ RelocationEntry RE(SectionID, Offset, RelType, Value.Addend, Value.Offset);
+ if (Value.SymbolName)
+ addRelocationForSymbol(RE, Value.SymbolName);
+ else
+ addRelocationForSection(RE, Value.SectionID);
+ }
+}
+
+void RuntimeDyldELF::updateGOTEntries(StringRef Name, uint64_t Addr) {
+
+ SmallVectorImpl<std::pair<SID, GOTRelocations> >::iterator it;
+ SmallVectorImpl<std::pair<SID, GOTRelocations> >::iterator end = GOTs.end();
+
+ for (it = GOTs.begin(); it != end; ++it) {
+ GOTRelocations &GOTEntries = it->second;
+ for (int i = 0, e = GOTEntries.size(); i != e; ++i) {
+ if (GOTEntries[i].SymbolName != 0 && GOTEntries[i].SymbolName == Name) {
+ GOTEntries[i].Offset = Addr;
+ }
+ }
+ }
+}
+
+size_t RuntimeDyldELF::getGOTEntrySize() {
+ // We don't use the GOT in all of these cases, but it's essentially free
+ // to put them all here.
+ size_t Result = 0;
+ switch (Arch) {
+ case Triple::x86_64:
+ case Triple::aarch64:
+ case Triple::ppc64:
+ case Triple::ppc64le:
+ case Triple::systemz:
+ Result = sizeof(uint64_t);
+ break;
+ case Triple::x86:
+ case Triple::arm:
+ case Triple::thumb:
+ case Triple::mips:
+ case Triple::mipsel:
+ Result = sizeof(uint32_t);
+ break;
+ default: llvm_unreachable("Unsupported CPU type!");
+ }
+ return Result;
+}
+
+uint64_t RuntimeDyldELF::findGOTEntry(uint64_t LoadAddress,
+ uint64_t Offset) {
+
+ const size_t GOTEntrySize = getGOTEntrySize();
+
+ SmallVectorImpl<std::pair<SID, GOTRelocations> >::const_iterator it;
+ SmallVectorImpl<std::pair<SID, GOTRelocations> >::const_iterator end = GOTs.end();
+
+ int GOTIndex = -1;
+ for (it = GOTs.begin(); it != end; ++it) {
+ SID GOTSectionID = it->first;
+ const GOTRelocations &GOTEntries = it->second;
+
+ // Find the matching entry in our vector.
+ uint64_t SymbolOffset = 0;
+ for (int i = 0, e = GOTEntries.size(); i != e; ++i) {
+ if (GOTEntries[i].SymbolName == 0) {
+ if (getSectionLoadAddress(GOTEntries[i].SectionID) == LoadAddress &&
+ GOTEntries[i].Offset == Offset) {
+ GOTIndex = i;
+ SymbolOffset = GOTEntries[i].Offset;
+ break;
+ }
+ } else {
+ // GOT entries for external symbols use the addend as the address when
+ // the external symbol has been resolved.
+ if (GOTEntries[i].Offset == LoadAddress) {
+ GOTIndex = i;
+ // Don't use the Addend here. The relocation handler will use it.
+ break;
+ }
+ }
+ }
+
+ if (GOTIndex != -1) {
+ if (GOTEntrySize == sizeof(uint64_t)) {
+ uint64_t *LocalGOTAddr = (uint64_t*)getSectionAddress(GOTSectionID);
+ // Fill in this entry with the address of the symbol being referenced.
+ LocalGOTAddr[GOTIndex] = LoadAddress + SymbolOffset;
+ } else {
+ uint32_t *LocalGOTAddr = (uint32_t*)getSectionAddress(GOTSectionID);
+ // Fill in this entry with the address of the symbol being referenced.
+ LocalGOTAddr[GOTIndex] = (uint32_t)(LoadAddress + SymbolOffset);
+ }
+
+ // Calculate the load address of this entry
+ return getSectionLoadAddress(GOTSectionID) + (GOTIndex * GOTEntrySize);
+ }
+ }
+
+ assert(GOTIndex != -1 && "Unable to find requested GOT entry.");
+ return 0;