//===----------------------------------------------------------------------===//
#include "RuntimeDyldELF.h"
+#include "RuntimeDyldCheckerImpl.h"
#include "llvm/ADT/IntervalMap.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/ADT/StringRef.h"
sym->st_value = static_cast<addr_type>(Addr);
}
-class LoadedELFObjectInfo : public RuntimeDyld::LoadedObjectInfo {
+class LoadedELFObjectInfo
+ : public RuntimeDyld::LoadedObjectInfoHelper<LoadedELFObjectInfo> {
public:
LoadedELFObjectInfo(RuntimeDyldImpl &RTDyld, unsigned BeginIdx,
unsigned EndIdx)
- : RuntimeDyld::LoadedObjectInfo(RTDyld, BeginIdx, EndIdx) {}
+ : LoadedObjectInfoHelper(RTDyld, BeginIdx, EndIdx) {}
OwningBinary<ObjectFile>
getObjectForDebug(const ObjectFile &Obj) const override;
namespace llvm {
-RuntimeDyldELF::RuntimeDyldELF(RTDyldMemoryManager *mm) : RuntimeDyldImpl(mm) {}
+RuntimeDyldELF::RuntimeDyldELF(RuntimeDyld::MemoryManager &MemMgr,
+ RuntimeDyld::SymbolResolver &Resolver)
+ : RuntimeDyldImpl(MemMgr, Resolver), GOTSectionID(0), CurrentGOTIndex(0) {}
RuntimeDyldELF::~RuntimeDyldELF() {}
void RuntimeDyldELF::registerEHFrames() {
- if (!MemMgr)
- return;
for (int i = 0, e = UnregisteredEHFrameSections.size(); i != e; ++i) {
SID EHFrameSID = UnregisteredEHFrameSections[i];
uint8_t *EHFrameAddr = Sections[EHFrameSID].Address;
uint64_t EHFrameLoadAddr = Sections[EHFrameSID].LoadAddress;
size_t EHFrameSize = Sections[EHFrameSID].Size;
- MemMgr->registerEHFrames(EHFrameAddr, EHFrameLoadAddr, EHFrameSize);
+ MemMgr.registerEHFrames(EHFrameAddr, EHFrameLoadAddr, EHFrameSize);
RegisteredEHFrameSections.push_back(EHFrameSID);
}
UnregisteredEHFrameSections.clear();
}
void RuntimeDyldELF::deregisterEHFrames() {
- if (!MemMgr)
- return;
for (int i = 0, e = RegisteredEHFrameSections.size(); i != e; ++i) {
SID EHFrameSID = RegisteredEHFrameSections[i];
uint8_t *EHFrameAddr = Sections[EHFrameSID].Address;
uint64_t EHFrameLoadAddr = Sections[EHFrameSID].LoadAddress;
size_t EHFrameSize = Sections[EHFrameSID].Size;
- MemMgr->deregisterEHFrames(EHFrameAddr, EHFrameLoadAddr, EHFrameSize);
+ MemMgr.deregisterEHFrames(EHFrameAddr, EHFrameLoadAddr, EHFrameSize);
}
RegisteredEHFrameSections.clear();
}
<< format("%p\n", Section.Address + Offset));
break;
}
- case ELF::R_X86_64_GOTPCREL: {
- // findGOTEntry returns the 'G + GOT' part of the relocation calculation
- // based on the load/target address of the GOT (not the current/local addr).
- uint64_t GOTAddr = findGOTEntry(Value, SymOffset);
- uint64_t FinalAddress = Section.LoadAddress + Offset;
- // The processRelocationRef method combines the symbol offset and the addend
- // and in most cases that's what we want. For this relocation type, we need
- // the raw addend, so we subtract the symbol offset to get it.
- int64_t RealOffset = GOTAddr + Addend - SymOffset - FinalAddress;
- assert(RealOffset <= INT32_MAX && RealOffset >= INT32_MIN);
- int32_t TruncOffset = (RealOffset & 0xFFFFFFFF);
- support::ulittle32_t::ref(Section.Address + Offset) = TruncOffset;
- break;
- }
case ELF::R_X86_64_PC32: {
- // Get the placeholder value from the generated object since
- // a previous relocation attempt may have overwritten the loaded version
- support::ulittle32_t::ref Placeholder(
- (void *)(Section.ObjAddress + Offset));
uint64_t FinalAddress = Section.LoadAddress + Offset;
- int64_t RealOffset = Placeholder + Value + Addend - FinalAddress;
- assert(RealOffset <= INT32_MAX && RealOffset >= INT32_MIN);
+ int64_t RealOffset = Value + Addend - FinalAddress;
+ assert(isInt<32>(RealOffset));
int32_t TruncOffset = (RealOffset & 0xFFFFFFFF);
support::ulittle32_t::ref(Section.Address + Offset) = TruncOffset;
break;
}
case ELF::R_X86_64_PC64: {
- // Get the placeholder value from the generated object since
- // a previous relocation attempt may have overwritten the loaded version
- support::ulittle64_t::ref Placeholder(
- (void *)(Section.ObjAddress + Offset));
uint64_t FinalAddress = Section.LoadAddress + Offset;
- support::ulittle64_t::ref(Section.Address + Offset) =
- Placeholder + Value + Addend - FinalAddress;
+ int64_t RealOffset = Value + Addend - FinalAddress;
+ support::ulittle64_t::ref(Section.Address + Offset) = RealOffset;
break;
}
}
uint32_t Type, int32_t Addend) {
switch (Type) {
case ELF::R_386_32: {
- // Get the placeholder value from the generated object since
- // a previous relocation attempt may have overwritten the loaded version
- support::ulittle32_t::ref Placeholder(
- (void *)(Section.ObjAddress + Offset));
- support::ulittle32_t::ref(Section.Address + Offset) =
- Placeholder + Value + Addend;
+ support::ulittle32_t::ref(Section.Address + Offset) = Value + Addend;
break;
}
case ELF::R_386_PC32: {
- // Get the placeholder value from the generated object since
- // a previous relocation attempt may have overwritten the loaded version
- support::ulittle32_t::ref Placeholder(
- (void *)(Section.ObjAddress + Offset));
uint32_t FinalAddress = ((Section.LoadAddress + Offset) & 0xFFFFFFFF);
- uint32_t RealOffset = Placeholder + Value + Addend - FinalAddress;
+ uint32_t RealOffset = Value + Addend - FinalAddress;
support::ulittle32_t::ref(Section.Address + Offset) = RealOffset;
break;
}
uint64_t BranchImm = Value + Addend - FinalAddress;
// "Check that -2^27 <= result < 2^27".
- assert(-(1LL << 27) <= static_cast<int64_t>(BranchImm) &&
- static_cast<int64_t>(BranchImm) < (1LL << 27));
+ assert(isInt<28>(BranchImm));
// AArch64 code is emitted with .rela relocations. The data already in any
// bits affected by the relocation on entry is garbage.
((Value + Addend) & ~0xfffULL) - (FinalAddress & ~0xfffULL);
// Check that -2^32 <= X < 2^32
- assert(static_cast<int64_t>(Result) >= (-1LL << 32) &&
- static_cast<int64_t>(Result) < (1LL << 32) &&
- "overflow check failed for relocation");
+ assert(isInt<33>(Result) && "overflow check failed for relocation");
// AArch64 code is emitted with .rela relocations. The data already in any
// bits affected by the relocation on entry is garbage.
uint64_t Offset, uint32_t Value,
uint32_t Type, int32_t Addend) {
// TODO: Add Thumb relocations.
- uint32_t *Placeholder =
- reinterpret_cast<uint32_t *>(Section.ObjAddress + Offset);
uint32_t *TargetPtr = (uint32_t *)(Section.Address + Offset);
uint32_t FinalAddress = ((Section.LoadAddress + Offset) & 0xFFFFFFFF);
Value += Addend;
case ELF::R_ARM_NONE:
break;
- // Write a 32bit value to relocation address, taking into account the
- // implicit addend encoded in the target.
case ELF::R_ARM_PREL31:
case ELF::R_ARM_TARGET1:
case ELF::R_ARM_ABS32:
- *TargetPtr = *Placeholder + Value;
+ *TargetPtr = Value;
break;
- // Write first 16 bit of 32 bit value to the mov instruction.
- // Last 4 bit should be shifted.
+ // Write first 16 bit of 32 bit value to the mov instruction.
+ // Last 4 bit should be shifted.
case ELF::R_ARM_MOVW_ABS_NC:
- // We are not expecting any other addend in the relocation address.
- // Using 0x000F0FFF because MOVW has its 16 bit immediate split into 2
- // non-contiguous fields.
- assert((*Placeholder & 0x000F0FFF) == 0);
- Value = Value & 0xFFFF;
- *TargetPtr = *Placeholder | (Value & 0xFFF);
- *TargetPtr |= ((Value >> 12) & 0xF) << 16;
- break;
- // Write last 16 bit of 32 bit value to the mov instruction.
- // Last 4 bit should be shifted.
case ELF::R_ARM_MOVT_ABS:
- // We are not expecting any other addend in the relocation address.
- // Use 0x000F0FFF for the same reason as R_ARM_MOVW_ABS_NC.
- assert((*Placeholder & 0x000F0FFF) == 0);
-
- Value = (Value >> 16) & 0xFFFF;
- *TargetPtr = *Placeholder | (Value & 0xFFF);
+ if (Type == ELF::R_ARM_MOVW_ABS_NC)
+ Value = Value & 0xFFFF;
+ else if (Type == ELF::R_ARM_MOVT_ABS)
+ Value = (Value >> 16) & 0xFFFF;
+ *TargetPtr &= ~0x000F0FFF;
+ *TargetPtr |= Value & 0xFFF;
*TargetPtr |= ((Value >> 12) & 0xF) << 16;
break;
- // Write 24 bit relative value to the branch instruction.
+ // Write 24 bit relative value to the branch instruction.
case ELF::R_ARM_PC24: // Fall through.
case ELF::R_ARM_CALL: // Fall through.
- case ELF::R_ARM_JUMP24: {
+ case ELF::R_ARM_JUMP24:
int32_t RelValue = static_cast<int32_t>(Value - FinalAddress - 8);
RelValue = (RelValue & 0x03FFFFFC) >> 2;
assert((*TargetPtr & 0xFFFFFF) == 0xFFFFFE);
*TargetPtr |= RelValue;
break;
}
- case ELF::R_ARM_PRIVATE_0:
- // This relocation is reserved by the ARM ELF ABI for internal use. We
- // appropriate it here to act as an R_ARM_ABS32 without any addend for use
- // in the stubs created during JIT (which can't put an addend into the
- // original object file).
- *TargetPtr = Value;
- break;
- }
}
void RuntimeDyldELF::resolveMIPSRelocation(const SectionEntry &Section,
uint64_t Offset, uint32_t Value,
uint32_t Type, int32_t Addend) {
- uint32_t *Placeholder =
- reinterpret_cast<uint32_t *>(Section.ObjAddress + Offset);
uint32_t *TargetPtr = (uint32_t *)(Section.Address + Offset);
Value += Addend;
llvm_unreachable("Not implemented relocation type!");
break;
case ELF::R_MIPS_32:
- *TargetPtr = Value + (*Placeholder);
+ *TargetPtr = Value;
break;
case ELF::R_MIPS_26:
- *TargetPtr = ((*Placeholder) & 0xfc000000) | ((Value & 0x0fffffff) >> 2);
+ *TargetPtr = ((*TargetPtr) & 0xfc000000) | ((Value & 0x0fffffff) >> 2);
break;
case ELF::R_MIPS_HI16:
// Get the higher 16-bits. Also add 1 if bit 15 is 1.
- Value += ((*Placeholder) & 0x0000ffff) << 16;
*TargetPtr =
- ((*Placeholder) & 0xffff0000) | (((Value + 0x8000) >> 16) & 0xffff);
+ ((*TargetPtr) & 0xffff0000) | (((Value + 0x8000) >> 16) & 0xffff);
break;
case ELF::R_MIPS_LO16:
- Value += ((*Placeholder) & 0x0000ffff);
- *TargetPtr = ((*Placeholder) & 0xffff0000) | (Value & 0xffff);
- break;
- case ELF::R_MIPS_UNUSED1:
- // Similar to ELF::R_ARM_PRIVATE_0, R_MIPS_UNUSED1 and R_MIPS_UNUSED2
- // are used for internal JIT purpose. These relocations are similar to
- // R_MIPS_HI16 and R_MIPS_LO16, but they do not take any addend into
- // account.
- *TargetPtr =
- ((*TargetPtr) & 0xffff0000) | (((Value + 0x8000) >> 16) & 0xffff);
- break;
- case ELF::R_MIPS_UNUSED2:
*TargetPtr = ((*TargetPtr) & 0xffff0000) | (Value & 0xffff);
break;
}
}
}
+void *RuntimeDyldELF::computePlaceholderAddress(unsigned SectionID, uint64_t Offset) const {
+ return (void*)(Sections[SectionID].ObjAddress + Offset);
+}
+
+void RuntimeDyldELF::processSimpleRelocation(unsigned SectionID, uint64_t Offset, unsigned RelType, RelocationValueRef Value) {
+ RelocationEntry RE(SectionID, Offset, RelType, Value.Addend, Value.Offset);
+ if (Value.SymbolName)
+ addRelocationForSymbol(RE, Value.SymbolName);
+ else
+ addRelocationForSection(RE, Value.SectionID);
+}
+
relocation_iterator RuntimeDyldELF::processRelocationRef(
unsigned SectionID, relocation_iterator RelI,
const ObjectFile &Obj,
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];
+ } else if (Arch == Triple::arm) {
+ if (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 =
+ // 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();
+ RelocationEntry RE(SectionID, StubTargetAddr - Section.Address,
+ ELF::R_ARM_ABS32, 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 {
+ uint32_t *Placeholder =
+ reinterpret_cast<uint32_t*>(computePlaceholderAddress(SectionID, Offset));
+ if (RelType == ELF::R_ARM_PREL31 || RelType == ELF::R_ARM_TARGET1 ||
+ RelType == ELF::R_ARM_ABS32) {
+ Value.Addend += *Placeholder;
+ } else if (RelType == ELF::R_ARM_MOVW_ABS_NC || RelType == ELF::R_ARM_MOVT_ABS) {
+ // See ELF for ARM documentation
+ Value.Addend += (int16_t)((*Placeholder & 0xFFF) | (((*Placeholder >> 16) & 0xF) << 12));
+ }
+ processSimpleRelocation(SectionID, Offset, RelType, Value);
}
- } 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;
+ } else if ((Arch == Triple::mipsel || Arch == Triple::mips)) {
+ uint32_t *Placeholder = reinterpret_cast<uint32_t*>(computePlaceholderAddress(SectionID, Offset));
+ if (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];
- // Extract the addend from the instruction.
- uint32_t Addend = ((*TargetAddress) & 0x03ffffff) << 2;
+ // Extract the addend from the instruction.
+ // We shift up by two since the Value will be down shifted again
+ // when applying the relocation.
+ uint32_t Addend = ((*Placeholder) & 0x03ffffff) << 2;
- Value.Addend += Addend;
+ 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 =
+ // 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);
+ // Creating Hi and Lo relocations for the filled stub instructions.
+ RelocationEntry REHi(SectionID, StubTargetAddr - Section.Address,
+ ELF::R_MIPS_HI16, Value.Addend);
+ RelocationEntry RELo(SectionID, StubTargetAddr - Section.Address + 4,
+ ELF::R_MIPS_LO16, Value.Addend);
- if (Value.SymbolName) {
- addRelocationForSymbol(REHi, Value.SymbolName);
- addRelocationForSymbol(RELo, Value.SymbolName);
- } else {
- addRelocationForSection(REHi, Value.SectionID);
- addRelocationForSection(RELo, Value.SectionID);
- }
+ 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();
+ RelocationEntry RE(SectionID, Offset, RelType, Section.StubOffset);
+ addRelocationForSection(RE, SectionID);
+ Section.StubOffset += getMaxStubSize();
+ }
+ } else {
+ if (RelType == ELF::R_MIPS_HI16)
+ Value.Addend += ((*Placeholder) & 0x0000ffff) << 16;
+ else if (RelType == ELF::R_MIPS_LO16)
+ Value.Addend += ((*Placeholder) & 0x0000ffff);
+ else if (RelType == ELF::R_MIPS_32)
+ Value.Addend += *Placeholder;
+ processSimpleRelocation(SectionID, Offset, RelType, Value);
}
} else if (Arch == Triple::ppc64 || Arch == Triple::ppc64le) {
if (RelType == ELF::R_PPC64_REL24) {
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()) {
+ } else if (Arch == Triple::x86_64) {
+ if (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 {
+ } 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;
+ -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();
+
+ // Allocate a GOT Entry
+ uint64_t GOTOffset = allocateGOTEntries(SectionID, 1);
+
+ // The load of the GOT address has an addend of -4
+ resolveGOTOffsetRelocation(SectionID, StubOffset + 2, GOTOffset - 4);
+
+ // Fill in the value of the symbol we're targeting into the GOT
+ addRelocationForSymbol(computeGOTOffsetRE(SectionID,GOTOffset,0,ELF::R_X86_64_64),
+ Value.SymbolName);
+ }
+
+ // 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 (RelType == ELF::R_X86_64_GOTPCREL) {
+ uint64_t GOTOffset = allocateGOTEntries(SectionID, 1);
+ resolveGOTOffsetRelocation(SectionID, Offset, GOTOffset + Addend);
- // Make the target call a call into the stub table.
- resolveRelocation(Section, Offset, StubAddress, ELF::R_X86_64_PC32,
- Addend);
+ // Fill in the value of the symbol we're targeting into the GOT
+ RelocationEntry RE = computeGOTOffsetRE(SectionID, GOTOffset, Value.Offset, ELF::R_X86_64_64);
+ if (Value.SymbolName)
+ addRelocationForSymbol(RE, Value.SymbolName);
+ else
+ addRelocationForSection(RE, Value.SectionID);
+ } else if (RelType == ELF::R_X86_64_PC32) {
+ Value.Addend += support::ulittle32_t::ref(computePlaceholderAddress(SectionID, Offset));
+ processSimpleRelocation(SectionID, Offset, RelType, Value);
+ } else if (RelType == ELF::R_X86_64_PC64) {
+ Value.Addend += support::ulittle64_t::ref(computePlaceholderAddress(SectionID, Offset));
+ processSimpleRelocation(SectionID, Offset, RelType, Value);
} else {
- RelocationEntry RE(SectionID, Offset, ELF::R_X86_64_PC32, Value.Addend,
- Value.Offset);
- addRelocationForSection(RE, Value.SectionID);
+ processSimpleRelocation(SectionID, Offset, RelType, Value);
}
} else {
- if (Arch == Triple::x86_64 && RelType == ELF::R_X86_64_GOTPCREL) {
- GOTEntries.push_back(Value);
+ if (Arch == Triple::x86) {
+ Value.Addend += support::ulittle32_t::ref(computePlaceholderAddress(SectionID, Offset));
}
- RelocationEntry RE(SectionID, Offset, RelType, Value.Addend, Value.Offset);
- if (Value.SymbolName)
- addRelocationForSymbol(RE, Value.SymbolName);
- else
- addRelocationForSection(RE, Value.SectionID);
+ processSimpleRelocation(SectionID, Offset, RelType, Value);
}
return ++RelI;
}
-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 != nullptr &&
- 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.
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) {
- 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);
- }
+uint64_t RuntimeDyldELF::allocateGOTEntries(unsigned SectionID, unsigned no)
+{
+ (void)SectionID; // The GOT Section is the same for all section in the object file
+ if (GOTSectionID == 0) {
+ GOTSectionID = Sections.size();
+ // Reserve a section id. We'll allocate the section later
+ // once we know the total size
+ Sections.push_back(SectionEntry(".got", 0, 0, 0));
}
+ uint64_t StartOffset = CurrentGOTIndex * getGOTEntrySize();
+ CurrentGOTIndex += no;
+ return StartOffset;
+}
+
+void RuntimeDyldELF::resolveGOTOffsetRelocation(unsigned SectionID, uint64_t Offset, uint64_t GOTOffset)
+{
+ // Fill in the relative address of the GOT Entry into the stub
+ RelocationEntry GOTRE(SectionID, Offset, ELF::R_X86_64_PC32, GOTOffset);
+ addRelocationForSection(GOTRE, GOTSectionID);
+}
- assert(GOTIndex != -1 && "Unable to find requested GOT entry.");
- return 0;
+RelocationEntry RuntimeDyldELF::computeGOTOffsetRE(unsigned SectionID, uint64_t GOTOffset, uint64_t SymbolOffset,
+ uint32_t Type)
+{
+ (void)SectionID; // The GOT Section is the same for all section in the object file
+ return RelocationEntry(GOTSectionID, GOTOffset, Type, SymbolOffset);
}
void RuntimeDyldELF::finalizeLoad(const ObjectFile &Obj,
ObjSectionToIDMap &SectionMap) {
// If necessary, allocate the global offset table
- if (MemMgr) {
- // Allocate the GOT if necessary
- size_t numGOTEntries = GOTEntries.size();
- if (numGOTEntries != 0) {
- // Allocate memory for the section
- unsigned SectionID = Sections.size();
- size_t TotalSize = numGOTEntries * getGOTEntrySize();
- uint8_t *Addr = MemMgr->allocateDataSection(TotalSize, getGOTEntrySize(),
- SectionID, ".got", false);
- if (!Addr)
- report_fatal_error("Unable to allocate memory for GOT!");
-
- GOTs.push_back(std::make_pair(SectionID, GOTEntries));
- Sections.push_back(SectionEntry(".got", Addr, TotalSize, 0));
- // For now, initialize all GOT entries to zero. We'll fill them in as
- // needed when GOT-based relocations are applied.
- memset(Addr, 0, TotalSize);
- }
- } else {
- report_fatal_error("Unable to allocate memory for GOT!");
+ if (GOTSectionID != 0) {
+ // Allocate memory for the section
+ size_t TotalSize = CurrentGOTIndex * getGOTEntrySize();
+ uint8_t *Addr = MemMgr.allocateDataSection(TotalSize, getGOTEntrySize(),
+ GOTSectionID, ".got", false);
+ if (!Addr)
+ report_fatal_error("Unable to allocate memory for GOT!");
+
+ Sections[GOTSectionID] = SectionEntry(".got", Addr, TotalSize, 0);
+
+ if (Checker)
+ Checker->registerSection(Obj.getFileName(), GOTSectionID);
+
+ // For now, initialize all GOT entries to zero. We'll fill them in as
+ // needed when GOT-based relocations are applied.
+ memset(Addr, 0, TotalSize);
}
// Look for and record the EH frame section.
break;
}
}
+
+ GOTSectionID = 0;
+ CurrentGOTIndex = 0;
}
bool RuntimeDyldELF::isCompatibleFile(const object::ObjectFile &Obj) const {
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