forked from OSchip/llvm-project
303 lines
11 KiB
C++
303 lines
11 KiB
C++
//===-- RuntimeDyldMachO.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 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 "RuntimeDyldMachO.h"
|
|
using namespace llvm;
|
|
using namespace llvm::object;
|
|
|
|
namespace llvm {
|
|
|
|
void RuntimeDyldMachO::resolveRelocation(uint8_t *LocalAddress,
|
|
uint64_t FinalAddress,
|
|
uint64_t Value,
|
|
uint32_t Type,
|
|
int64_t Addend) {
|
|
bool isPCRel = (Type >> 24) & 1;
|
|
unsigned MachoType = (Type >> 28) & 0xf;
|
|
unsigned Size = 1 << ((Type >> 25) & 3);
|
|
|
|
DEBUG(dbgs() << "resolveRelocation LocalAddress: "
|
|
<< format("%p", LocalAddress)
|
|
<< " FinalAddress: " << format("%p", FinalAddress)
|
|
<< " Value: " << format("%p", Value)
|
|
<< " Addend: " << Addend
|
|
<< " isPCRel: " << isPCRel
|
|
<< " MachoType: " << MachoType
|
|
<< " Size: " << Size
|
|
<< "\n");
|
|
|
|
// This just dispatches to the proper target specific routine.
|
|
switch (Arch) {
|
|
default: llvm_unreachable("Unsupported CPU type!");
|
|
case Triple::x86_64:
|
|
resolveX86_64Relocation(LocalAddress,
|
|
FinalAddress,
|
|
(uintptr_t)Value,
|
|
isPCRel,
|
|
MachoType,
|
|
Size,
|
|
Addend);
|
|
break;
|
|
case Triple::x86:
|
|
resolveI386Relocation(LocalAddress,
|
|
FinalAddress,
|
|
(uintptr_t)Value,
|
|
isPCRel,
|
|
Type,
|
|
Size,
|
|
Addend);
|
|
break;
|
|
case Triple::arm: // Fall through.
|
|
case Triple::thumb:
|
|
resolveARMRelocation(LocalAddress,
|
|
FinalAddress,
|
|
(uintptr_t)Value,
|
|
isPCRel,
|
|
MachoType,
|
|
Size,
|
|
Addend);
|
|
break;
|
|
}
|
|
}
|
|
|
|
bool RuntimeDyldMachO::resolveI386Relocation(uint8_t *LocalAddress,
|
|
uint64_t FinalAddress,
|
|
uint64_t Value,
|
|
bool isPCRel,
|
|
unsigned Type,
|
|
unsigned Size,
|
|
int64_t Addend) {
|
|
if (isPCRel)
|
|
Value -= FinalAddress + 4; // see resolveX86_64Relocation
|
|
|
|
switch (Type) {
|
|
default:
|
|
llvm_unreachable("Invalid relocation type!");
|
|
case macho::RIT_Vanilla: {
|
|
uint8_t *p = LocalAddress;
|
|
uint64_t ValueToWrite = Value + Addend;
|
|
for (unsigned i = 0; i < Size; ++i) {
|
|
*p++ = (uint8_t)(ValueToWrite & 0xff);
|
|
ValueToWrite >>= 8;
|
|
}
|
|
}
|
|
case macho::RIT_Difference:
|
|
case macho::RIT_Generic_LocalDifference:
|
|
case macho::RIT_Generic_PreboundLazyPointer:
|
|
return Error("Relocation type not implemented yet!");
|
|
}
|
|
}
|
|
|
|
bool RuntimeDyldMachO::resolveX86_64Relocation(uint8_t *LocalAddress,
|
|
uint64_t FinalAddress,
|
|
uint64_t Value,
|
|
bool isPCRel,
|
|
unsigned Type,
|
|
unsigned Size,
|
|
int64_t Addend) {
|
|
// If the relocation is PC-relative, the value to be encoded is the
|
|
// pointer difference.
|
|
if (isPCRel)
|
|
// FIXME: It seems this value needs to be adjusted by 4 for an effective PC
|
|
// address. Is that expected? Only for branches, perhaps?
|
|
Value -= FinalAddress + 4;
|
|
|
|
switch(Type) {
|
|
default:
|
|
llvm_unreachable("Invalid relocation type!");
|
|
case macho::RIT_X86_64_Signed1:
|
|
case macho::RIT_X86_64_Signed2:
|
|
case macho::RIT_X86_64_Signed4:
|
|
case macho::RIT_X86_64_Signed:
|
|
case macho::RIT_X86_64_Unsigned:
|
|
case macho::RIT_X86_64_Branch: {
|
|
Value += Addend;
|
|
// Mask in the target value a byte at a time (we don't have an alignment
|
|
// guarantee for the target address, so this is safest).
|
|
uint8_t *p = (uint8_t*)LocalAddress;
|
|
for (unsigned i = 0; i < Size; ++i) {
|
|
*p++ = (uint8_t)Value;
|
|
Value >>= 8;
|
|
}
|
|
return false;
|
|
}
|
|
case macho::RIT_X86_64_GOTLoad:
|
|
case macho::RIT_X86_64_GOT:
|
|
case macho::RIT_X86_64_Subtractor:
|
|
case macho::RIT_X86_64_TLV:
|
|
return Error("Relocation type not implemented yet!");
|
|
}
|
|
}
|
|
|
|
bool RuntimeDyldMachO::resolveARMRelocation(uint8_t *LocalAddress,
|
|
uint64_t FinalAddress,
|
|
uint64_t Value,
|
|
bool isPCRel,
|
|
unsigned Type,
|
|
unsigned Size,
|
|
int64_t Addend) {
|
|
// If the relocation is PC-relative, the value to be encoded is the
|
|
// pointer difference.
|
|
if (isPCRel) {
|
|
Value -= FinalAddress;
|
|
// ARM PCRel relocations have an effective-PC offset of two instructions
|
|
// (four bytes in Thumb mode, 8 bytes in ARM mode).
|
|
// FIXME: For now, assume ARM mode.
|
|
Value -= 8;
|
|
}
|
|
|
|
switch(Type) {
|
|
default:
|
|
llvm_unreachable("Invalid relocation type!");
|
|
case macho::RIT_Vanilla: {
|
|
// Mask in the target value a byte at a time (we don't have an alignment
|
|
// guarantee for the target address, so this is safest).
|
|
uint8_t *p = (uint8_t*)LocalAddress;
|
|
for (unsigned i = 0; i < Size; ++i) {
|
|
*p++ = (uint8_t)Value;
|
|
Value >>= 8;
|
|
}
|
|
break;
|
|
}
|
|
case macho::RIT_ARM_Branch24Bit: {
|
|
// Mask the value into the target address. We know instructions are
|
|
// 32-bit aligned, so we can do it all at once.
|
|
uint32_t *p = (uint32_t*)LocalAddress;
|
|
// The low two bits of the value are not encoded.
|
|
Value >>= 2;
|
|
// Mask the value to 24 bits.
|
|
Value &= 0xffffff;
|
|
// FIXME: If the destination is a Thumb function (and the instruction
|
|
// is a non-predicated BL instruction), we need to change it to a BLX
|
|
// instruction instead.
|
|
|
|
// Insert the value into the instruction.
|
|
*p = (*p & ~0xffffff) | Value;
|
|
break;
|
|
}
|
|
case macho::RIT_ARM_ThumbBranch22Bit:
|
|
case macho::RIT_ARM_ThumbBranch32Bit:
|
|
case macho::RIT_ARM_Half:
|
|
case macho::RIT_ARM_HalfDifference:
|
|
case macho::RIT_Pair:
|
|
case macho::RIT_Difference:
|
|
case macho::RIT_ARM_LocalDifference:
|
|
case macho::RIT_ARM_PreboundLazyPointer:
|
|
return Error("Relocation type not implemented yet!");
|
|
}
|
|
return false;
|
|
}
|
|
|
|
void RuntimeDyldMachO::processRelocationRef(const ObjRelocationInfo &Rel,
|
|
ObjectImage &Obj,
|
|
ObjSectionToIDMap &ObjSectionToID,
|
|
const SymbolTableMap &Symbols,
|
|
StubMap &Stubs) {
|
|
|
|
uint32_t RelType = (uint32_t) (Rel.Type & 0xffffffffL);
|
|
RelocationValueRef Value;
|
|
SectionEntry &Section = Sections[Rel.SectionID];
|
|
uint8_t *Target = Section.Address + Rel.Offset;
|
|
|
|
bool isExtern = (RelType >> 27) & 1;
|
|
if (isExtern) {
|
|
// Obtain the symbol name which is referenced in the relocation
|
|
StringRef TargetName;
|
|
const SymbolRef &Symbol = Rel.Symbol;
|
|
Symbol.getName(TargetName);
|
|
// First search for the symbol in the local symbol table
|
|
SymbolTableMap::const_iterator lsi = Symbols.find(TargetName.data());
|
|
if (lsi != Symbols.end()) {
|
|
Value.SectionID = lsi->second.first;
|
|
Value.Addend = lsi->second.second;
|
|
} else {
|
|
// Search for the symbol in the global symbol table
|
|
SymbolTableMap::const_iterator gsi = GlobalSymbolTable.find(TargetName.data());
|
|
if (gsi != GlobalSymbolTable.end()) {
|
|
Value.SectionID = gsi->second.first;
|
|
Value.Addend = gsi->second.second;
|
|
} else
|
|
Value.SymbolName = TargetName.data();
|
|
}
|
|
} else {
|
|
error_code err;
|
|
uint8_t sectionIndex = static_cast<uint8_t>(RelType & 0xFF);
|
|
section_iterator si = Obj.begin_sections(),
|
|
se = Obj.end_sections();
|
|
for (uint8_t i = 1; i < sectionIndex; i++) {
|
|
error_code err;
|
|
si.increment(err);
|
|
if (si == se)
|
|
break;
|
|
}
|
|
assert(si != se && "No section containing relocation!");
|
|
Value.SectionID = findOrEmitSection(Obj, *si, true, ObjSectionToID);
|
|
Value.Addend = *(const intptr_t *)Target;
|
|
if (Value.Addend) {
|
|
// The MachO addend is an offset from the current section. We need it
|
|
// to be an offset from the destination section
|
|
Value.Addend += Section.ObjAddress - Sections[Value.SectionID].ObjAddress;
|
|
}
|
|
}
|
|
|
|
if (Arch == Triple::arm && RelType == macho::RIT_ARM_Branch24Bit) {
|
|
// This is an ARM branch relocation, need to use a stub function.
|
|
|
|
// Look up for existing stub.
|
|
StubMap::const_iterator i = Stubs.find(Value);
|
|
if (i != Stubs.end())
|
|
resolveRelocation(Target, (uint64_t)Target,
|
|
(uint64_t)Section.Address + i->second,
|
|
RelType, 0);
|
|
else {
|
|
// Create a new stub function.
|
|
Stubs[Value] = Section.StubOffset;
|
|
uint8_t *StubTargetAddr = createStubFunction(Section.Address +
|
|
Section.StubOffset);
|
|
RelocationEntry RE(Rel.SectionID, StubTargetAddr - Section.Address,
|
|
macho::RIT_Vanilla, Value.Addend);
|
|
if (Value.SymbolName)
|
|
addRelocationForSymbol(RE, Value.SymbolName);
|
|
else
|
|
addRelocationForSection(RE, Value.SectionID);
|
|
resolveRelocation(Target, (uint64_t)Target,
|
|
(uint64_t)Section.Address + Section.StubOffset,
|
|
RelType, 0);
|
|
Section.StubOffset += getMaxStubSize();
|
|
}
|
|
} else {
|
|
RelocationEntry RE(Rel.SectionID, Rel.Offset, RelType, Value.Addend);
|
|
if (Value.SymbolName)
|
|
addRelocationForSymbol(RE, Value.SymbolName);
|
|
else
|
|
addRelocationForSection(RE, Value.SectionID);
|
|
}
|
|
}
|
|
|
|
|
|
bool RuntimeDyldMachO::isCompatibleFormat(
|
|
const MemoryBuffer *InputBuffer) const {
|
|
StringRef Magic = InputBuffer->getBuffer().slice(0, 4);
|
|
if (Magic == "\xFE\xED\xFA\xCE") return true;
|
|
if (Magic == "\xCE\xFA\xED\xFE") return true;
|
|
if (Magic == "\xFE\xED\xFA\xCF") return true;
|
|
if (Magic == "\xCF\xFA\xED\xFE") return true;
|
|
return false;
|
|
}
|
|
|
|
} // end namespace llvm
|