forked from OSchip/llvm-project
262 lines
9.6 KiB
C++
262 lines
9.6 KiB
C++
//===-- RuntimeDyldELF.cpp - Run-time dynamic linker for MC-JIT -*- C++ -*-===//
|
|
//
|
|
// The LLVM Compiler Infrastructure
|
|
//
|
|
// This file is distributed under the University of Illinois Open Source
|
|
// License. See LICENSE.TXT for details.
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
//
|
|
// Implementation of ELF support for the MC-JIT runtime dynamic linker.
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
#define DEBUG_TYPE "dyld"
|
|
#include "llvm/ADT/OwningPtr.h"
|
|
#include "llvm/ADT/StringRef.h"
|
|
#include "llvm/ADT/STLExtras.h"
|
|
#include "llvm/ADT/IntervalMap.h"
|
|
#include "RuntimeDyldELF.h"
|
|
#include "llvm/Object/ObjectFile.h"
|
|
#include "llvm/Support/ELF.h"
|
|
#include "llvm/ADT/Triple.h"
|
|
using namespace llvm;
|
|
using namespace llvm::object;
|
|
|
|
namespace llvm {
|
|
|
|
|
|
void RuntimeDyldELF::resolveX86_64Relocation(uint8_t *LocalAddress,
|
|
uint64_t FinalAddress,
|
|
uint64_t Value,
|
|
uint32_t Type,
|
|
int64_t Addend) {
|
|
switch (Type) {
|
|
default:
|
|
llvm_unreachable("Relocation type not implemented yet!");
|
|
break;
|
|
case ELF::R_X86_64_64: {
|
|
uint64_t *Target = (uint64_t*)(LocalAddress);
|
|
*Target = Value + Addend;
|
|
break;
|
|
}
|
|
case ELF::R_X86_64_32:
|
|
case ELF::R_X86_64_32S: {
|
|
Value += Addend;
|
|
// FIXME: Handle the possibility of this assertion failing
|
|
assert((Type == ELF::R_X86_64_32 && !(Value & 0xFFFFFFFF00000000ULL)) ||
|
|
(Type == ELF::R_X86_64_32S &&
|
|
(Value & 0xFFFFFFFF00000000ULL) == 0xFFFFFFFF00000000ULL));
|
|
uint32_t TruncatedAddr = (Value & 0xFFFFFFFF);
|
|
uint32_t *Target = reinterpret_cast<uint32_t*>(LocalAddress);
|
|
*Target = TruncatedAddr;
|
|
break;
|
|
}
|
|
case ELF::R_X86_64_PC32: {
|
|
uint32_t *Placeholder = reinterpret_cast<uint32_t*>(LocalAddress);
|
|
int64_t RealOffset = *Placeholder + Value + Addend - FinalAddress;
|
|
assert(RealOffset <= 214783647 && RealOffset >= -214783648);
|
|
int32_t TruncOffset = (RealOffset & 0xFFFFFFFF);
|
|
*Placeholder = TruncOffset;
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
|
|
void RuntimeDyldELF::resolveX86Relocation(uint8_t *LocalAddress,
|
|
uint32_t FinalAddress,
|
|
uint32_t Value,
|
|
uint32_t Type,
|
|
int32_t Addend) {
|
|
switch (Type) {
|
|
case ELF::R_386_32: {
|
|
uint32_t *Target = (uint32_t*)(LocalAddress);
|
|
*Target = Value + Addend;
|
|
break;
|
|
}
|
|
case ELF::R_386_PC32: {
|
|
uint32_t *Placeholder = reinterpret_cast<uint32_t*>(LocalAddress);
|
|
uint32_t RealOffset = *Placeholder + Value + Addend - FinalAddress;
|
|
*Placeholder = RealOffset;
|
|
break;
|
|
}
|
|
default:
|
|
// There are other relocation types, but it appears these are the
|
|
// only ones currently used by the LLVM ELF object writer
|
|
llvm_unreachable("Relocation type not implemented yet!");
|
|
break;
|
|
}
|
|
}
|
|
|
|
void RuntimeDyldELF::resolveARMRelocation(uint8_t *LocalAddress,
|
|
uint32_t FinalAddress,
|
|
uint32_t Value,
|
|
uint32_t Type,
|
|
int32_t Addend) {
|
|
// TODO: Add Thumb relocations.
|
|
uint32_t* TargetPtr = (uint32_t*)LocalAddress;
|
|
Value += Addend;
|
|
|
|
DEBUG(dbgs() << "resolveARMRelocation, LocalAddress: " << LocalAddress
|
|
<< " FinalAddress: " << format("%p",FinalAddress)
|
|
<< " Value: " << format("%x",Value)
|
|
<< " Type: " << format("%x",Type)
|
|
<< " Addend: " << format("%x",Addend)
|
|
<< "\n");
|
|
|
|
switch(Type) {
|
|
default:
|
|
llvm_unreachable("Not implemented relocation type!");
|
|
|
|
// Just write 32bit value to relocation address
|
|
case ELF::R_ARM_ABS32 :
|
|
*TargetPtr = Value;
|
|
break;
|
|
|
|
// 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 :
|
|
Value = Value & 0xFFFF;
|
|
*TargetPtr |= 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 :
|
|
Value = (Value >> 16) & 0xFFFF;
|
|
*TargetPtr |= Value & 0xFFF;
|
|
*TargetPtr |= ((Value >> 12) & 0xF) << 16;
|
|
break;
|
|
|
|
// 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 :
|
|
int32_t RelValue = static_cast<int32_t>(Value - FinalAddress - 8);
|
|
RelValue = (RelValue & 0x03FFFFFC) >> 2;
|
|
*TargetPtr &= 0xFF000000;
|
|
*TargetPtr |= RelValue;
|
|
break;
|
|
}
|
|
}
|
|
|
|
void RuntimeDyldELF::resolveRelocation(uint8_t *LocalAddress,
|
|
uint64_t FinalAddress,
|
|
uint64_t Value,
|
|
uint32_t Type,
|
|
int64_t Addend) {
|
|
switch (Arch) {
|
|
case Triple::x86_64:
|
|
resolveX86_64Relocation(LocalAddress, FinalAddress, Value, Type, Addend);
|
|
break;
|
|
case Triple::x86:
|
|
resolveX86Relocation(LocalAddress, (uint32_t)(FinalAddress & 0xffffffffL),
|
|
(uint32_t)(Value & 0xffffffffL), Type,
|
|
(uint32_t)(Addend & 0xffffffffL));
|
|
break;
|
|
case Triple::arm: // Fall through.
|
|
case Triple::thumb:
|
|
resolveARMRelocation(LocalAddress, (uint32_t)(FinalAddress & 0xffffffffL),
|
|
(uint32_t)(Value & 0xffffffffL), Type,
|
|
(uint32_t)(Addend & 0xffffffffL));
|
|
break;
|
|
default: llvm_unreachable("Unsupported CPU type!");
|
|
}
|
|
}
|
|
|
|
void RuntimeDyldELF::processRelocationRef(const ObjRelocationInfo &Rel,
|
|
const ObjectFile &Obj,
|
|
ObjSectionToIDMap &ObjSectionToID,
|
|
LocalSymbolMap &Symbols,
|
|
StubMap &Stubs) {
|
|
|
|
uint32_t RelType = (uint32_t)(Rel.Type & 0xffffffffL);
|
|
intptr_t Addend = (intptr_t)Rel.AdditionalInfo;
|
|
RelocationValueRef Value;
|
|
StringRef TargetName;
|
|
const SymbolRef &Symbol = Rel.Symbol;
|
|
Symbol.getName(TargetName);
|
|
DEBUG(dbgs() << "\t\tRelType: " << RelType
|
|
<< " Addend: " << Addend
|
|
<< " TargetName: " << TargetName
|
|
<< "\n");
|
|
// First look the symbol in object file symbols.
|
|
LocalSymbolMap::iterator lsi = Symbols.find(TargetName.data());
|
|
if (lsi != Symbols.end()) {
|
|
Value.SectionID = lsi->second.first;
|
|
Value.Addend = lsi->second.second;
|
|
} else {
|
|
// Second look the symbol in global symbol table.
|
|
StringMap<SymbolLoc>::iterator gsi = SymbolTable.find(TargetName.data());
|
|
if (gsi != SymbolTable.end()) {
|
|
Value.SectionID = gsi->second.first;
|
|
Value.Addend = gsi->second.second;
|
|
} else {
|
|
SymbolRef::Type SymType;
|
|
Symbol.getType(SymType);
|
|
switch (SymType) {
|
|
case SymbolRef::ST_Debug: {
|
|
// TODO: Now ELF SymbolRef::ST_Debug = STT_SECTION, it's not obviously
|
|
// and can be changed by another developers. Maybe best way is add
|
|
// a new symbol type ST_Section to SymbolRef and use it.
|
|
section_iterator si = Obj.end_sections();
|
|
Symbol.getSection(si);
|
|
if (si == Obj.end_sections())
|
|
llvm_unreachable("Symbol section not found, bad object file format!");
|
|
DEBUG(dbgs() << "\t\tThis is section symbol\n");
|
|
Value.SectionID = findOrEmitSection((*si), true, ObjSectionToID);
|
|
Value.Addend = Addend;
|
|
break;
|
|
}
|
|
case SymbolRef::ST_Unknown: {
|
|
Value.SymbolName = TargetName.data();
|
|
Value.Addend = Addend;
|
|
break;
|
|
}
|
|
default:
|
|
llvm_unreachable("Unresolved symbol type!");
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
DEBUG(dbgs() << "\t\tRel.SectionID: " << Rel.SectionID
|
|
<< " Rel.Offset: " << Rel.Offset
|
|
<< "\n");
|
|
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[Rel.SectionID];
|
|
uint8_t *Target = Section.Address + Rel.Offset;
|
|
|
|
// Look up for existing stub.
|
|
StubMap::const_iterator i = Stubs.find(Value);
|
|
if (i != Stubs.end()) {
|
|
resolveRelocation(Target, Section.LoadAddress, (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);
|
|
AddRelocation(Value, Rel.SectionID,
|
|
StubTargetAddr - Section.Address, ELF::R_ARM_ABS32);
|
|
resolveRelocation(Target, Section.LoadAddress, (uint64_t)Section.Address +
|
|
Section.StubOffset, RelType, 0);
|
|
Section.StubOffset += getMaxStubSize();
|
|
}
|
|
} else
|
|
AddRelocation(Value, Rel.SectionID, Rel.Offset, RelType);
|
|
}
|
|
|
|
bool RuntimeDyldELF::isCompatibleFormat(const MemoryBuffer *InputBuffer) const {
|
|
StringRef Magic = InputBuffer->getBuffer().slice(0, ELF::EI_NIDENT);
|
|
return (memcmp(Magic.data(), ELF::ElfMagic, strlen(ELF::ElfMagic))) == 0;
|
|
}
|
|
} // namespace llvm
|