llvm-6502/lib/ExecutionEngine/RuntimeDyld/Targets/RuntimeDyldMachOAArch64.h
Lang Hames f0ad482410 [MCJIT] Rewrite RuntimeDyldMachO and its derived classes to use the 'Offset'
field of RelocationValueRef, rather than the 'Addend' field.

This is consistent with RuntimeDyldELF's use of RelocationValueRef, and more
consistent with the semantics of the data being stored (the offset from the
start of a section or symbol).



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@217328 91177308-0d34-0410-b5e6-96231b3b80d8
2014-09-07 04:03:32 +00:00

406 lines
16 KiB
C++

//===-- RuntimeDyldMachOAArch64.h -- MachO/AArch64 specific code. -*- C++ -*-=//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_LIB_EXECUTIONENGINE_RUNTIMEDYLD_TARGETS_RUNTIMEDYLDMACHOAARCH64_H
#define LLVM_LIB_EXECUTIONENGINE_RUNTIMEDYLD_TARGETS_RUNTIMEDYLDMACHOAARCH64_H
#include "../RuntimeDyldMachO.h"
#include "llvm/Support/Endian.h"
#define DEBUG_TYPE "dyld"
namespace llvm {
class RuntimeDyldMachOAArch64
: public RuntimeDyldMachOCRTPBase<RuntimeDyldMachOAArch64> {
public:
typedef uint64_t TargetPtrT;
RuntimeDyldMachOAArch64(RTDyldMemoryManager *MM)
: RuntimeDyldMachOCRTPBase(MM) {}
unsigned getMaxStubSize() override { return 8; }
unsigned getStubAlignment() override { return 8; }
/// Extract the addend encoded in the instruction / memory location.
int64_t decodeAddend(const RelocationEntry &RE) const {
const SectionEntry &Section = Sections[RE.SectionID];
uint8_t *LocalAddress = Section.Address + RE.Offset;
unsigned NumBytes = 1 << RE.Size;
int64_t Addend = 0;
// Verify that the relocation has the correct size and alignment.
switch (RE.RelType) {
default:
llvm_unreachable("Unsupported relocation type!");
case MachO::ARM64_RELOC_UNSIGNED:
assert((NumBytes == 4 || NumBytes == 8) && "Invalid relocation size.");
break;
case MachO::ARM64_RELOC_BRANCH26:
case MachO::ARM64_RELOC_PAGE21:
case MachO::ARM64_RELOC_PAGEOFF12:
case MachO::ARM64_RELOC_GOT_LOAD_PAGE21:
case MachO::ARM64_RELOC_GOT_LOAD_PAGEOFF12:
assert(NumBytes == 4 && "Invalid relocation size.");
assert((((uintptr_t)LocalAddress & 0x3) == 0) &&
"Instruction address is not aligned to 4 bytes.");
break;
}
switch (RE.RelType) {
default:
llvm_unreachable("Unsupported relocation type!");
case MachO::ARM64_RELOC_UNSIGNED:
// This could be an unaligned memory location.
if (NumBytes == 4)
Addend = *reinterpret_cast<support::ulittle32_t *>(LocalAddress);
else
Addend = *reinterpret_cast<support::ulittle64_t *>(LocalAddress);
break;
case MachO::ARM64_RELOC_BRANCH26: {
// Verify that the relocation points to the expected branch instruction.
auto *p = reinterpret_cast<support::aligned_ulittle32_t *>(LocalAddress);
assert((*p & 0xFC000000) == 0x14000000 && "Expected branch instruction.");
// Get the 26 bit addend encoded in the branch instruction and sign-extend
// to 64 bit. The lower 2 bits are always zeros and are therefore implicit
// (<< 2).
Addend = (*p & 0x03FFFFFF) << 2;
Addend = SignExtend64(Addend, 28);
break;
}
case MachO::ARM64_RELOC_GOT_LOAD_PAGE21:
case MachO::ARM64_RELOC_PAGE21: {
// Verify that the relocation points to the expected adrp instruction.
auto *p = reinterpret_cast<support::aligned_ulittle32_t *>(LocalAddress);
assert((*p & 0x9F000000) == 0x90000000 && "Expected adrp instruction.");
// Get the 21 bit addend encoded in the adrp instruction and sign-extend
// to 64 bit. The lower 12 bits (4096 byte page) are always zeros and are
// therefore implicit (<< 12).
Addend = ((*p & 0x60000000) >> 29) | ((*p & 0x01FFFFE0) >> 3) << 12;
Addend = SignExtend64(Addend, 33);
break;
}
case MachO::ARM64_RELOC_GOT_LOAD_PAGEOFF12: {
// Verify that the relocation points to one of the expected load / store
// instructions.
auto *p = reinterpret_cast<support::aligned_ulittle32_t *>(LocalAddress);
(void)p;
assert((*p & 0x3B000000) == 0x39000000 &&
"Only expected load / store instructions.");
} // fall-through
case MachO::ARM64_RELOC_PAGEOFF12: {
// Verify that the relocation points to one of the expected load / store
// or add / sub instructions.
auto *p = reinterpret_cast<support::aligned_ulittle32_t *>(LocalAddress);
assert((((*p & 0x3B000000) == 0x39000000) ||
((*p & 0x11C00000) == 0x11000000) ) &&
"Expected load / store or add/sub instruction.");
// Get the 12 bit addend encoded in the instruction.
Addend = (*p & 0x003FFC00) >> 10;
// Check which instruction we are decoding to obtain the implicit shift
// factor of the instruction.
int ImplicitShift = 0;
if ((*p & 0x3B000000) == 0x39000000) { // << load / store
// For load / store instructions the size is encoded in bits 31:30.
ImplicitShift = ((*p >> 30) & 0x3);
if (ImplicitShift == 0) {
// Check if this a vector op to get the correct shift value.
if ((*p & 0x04800000) == 0x04800000)
ImplicitShift = 4;
}
}
// Compensate for implicit shift.
Addend <<= ImplicitShift;
break;
}
}
return Addend;
}
/// Extract the addend encoded in the instruction.
void encodeAddend(uint8_t *LocalAddress, unsigned NumBytes,
MachO::RelocationInfoType RelType, int64_t Addend) const {
// Verify that the relocation has the correct alignment.
switch (RelType) {
default:
llvm_unreachable("Unsupported relocation type!");
case MachO::ARM64_RELOC_UNSIGNED:
assert((NumBytes == 4 || NumBytes == 8) && "Invalid relocation size.");
break;
case MachO::ARM64_RELOC_BRANCH26:
case MachO::ARM64_RELOC_PAGE21:
case MachO::ARM64_RELOC_PAGEOFF12:
case MachO::ARM64_RELOC_GOT_LOAD_PAGE21:
case MachO::ARM64_RELOC_GOT_LOAD_PAGEOFF12:
assert(NumBytes == 4 && "Invalid relocation size.");
assert((((uintptr_t)LocalAddress & 0x3) == 0) &&
"Instruction address is not aligned to 4 bytes.");
break;
}
switch (RelType) {
default:
llvm_unreachable("Unsupported relocation type!");
case MachO::ARM64_RELOC_UNSIGNED:
// This could be an unaligned memory location.
if (NumBytes == 4)
*reinterpret_cast<support::ulittle32_t *>(LocalAddress) = Addend;
else
*reinterpret_cast<support::ulittle64_t *>(LocalAddress) = Addend;
break;
case MachO::ARM64_RELOC_BRANCH26: {
auto *p = reinterpret_cast<support::aligned_ulittle32_t *>(LocalAddress);
// Verify that the relocation points to the expected branch instruction.
assert((*p & 0xFC000000) == 0x14000000 && "Expected branch instruction.");
// Verify addend value.
assert((Addend & 0x3) == 0 && "Branch target is not aligned");
assert(isInt<28>(Addend) && "Branch target is out of range.");
// Encode the addend as 26 bit immediate in the branch instruction.
*p = (*p & 0xFC000000) | ((uint32_t)(Addend >> 2) & 0x03FFFFFF);
break;
}
case MachO::ARM64_RELOC_GOT_LOAD_PAGE21:
case MachO::ARM64_RELOC_PAGE21: {
// Verify that the relocation points to the expected adrp instruction.
auto *p = reinterpret_cast<support::aligned_ulittle32_t *>(LocalAddress);
assert((*p & 0x9F000000) == 0x90000000 && "Expected adrp instruction.");
// Check that the addend fits into 21 bits (+ 12 lower bits).
assert((Addend & 0xFFF) == 0 && "ADRP target is not page aligned.");
assert(isInt<33>(Addend) && "Invalid page reloc value.");
// Encode the addend into the instruction.
uint32_t ImmLoValue = (uint32_t)(Addend << 17) & 0x60000000;
uint32_t ImmHiValue = (uint32_t)(Addend >> 9) & 0x00FFFFE0;
*p = (*p & 0x9F00001F) | ImmHiValue | ImmLoValue;
break;
}
case MachO::ARM64_RELOC_GOT_LOAD_PAGEOFF12: {
// Verify that the relocation points to one of the expected load / store
// instructions.
auto *p = reinterpret_cast<support::aligned_ulittle32_t *>(LocalAddress);
assert((*p & 0x3B000000) == 0x39000000 &&
"Only expected load / store instructions.");
(void)p;
} // fall-through
case MachO::ARM64_RELOC_PAGEOFF12: {
// Verify that the relocation points to one of the expected load / store
// or add / sub instructions.
auto *p = reinterpret_cast<support::aligned_ulittle32_t *>(LocalAddress);
assert((((*p & 0x3B000000) == 0x39000000) ||
((*p & 0x11C00000) == 0x11000000) ) &&
"Expected load / store or add/sub instruction.");
// Check which instruction we are decoding to obtain the implicit shift
// factor of the instruction and verify alignment.
int ImplicitShift = 0;
if ((*p & 0x3B000000) == 0x39000000) { // << load / store
// For load / store instructions the size is encoded in bits 31:30.
ImplicitShift = ((*p >> 30) & 0x3);
switch (ImplicitShift) {
case 0:
// Check if this a vector op to get the correct shift value.
if ((*p & 0x04800000) == 0x04800000) {
ImplicitShift = 4;
assert(((Addend & 0xF) == 0) &&
"128-bit LDR/STR not 16-byte aligned.");
}
break;
case 1:
assert(((Addend & 0x1) == 0) && "16-bit LDR/STR not 2-byte aligned.");
break;
case 2:
assert(((Addend & 0x3) == 0) && "32-bit LDR/STR not 4-byte aligned.");
break;
case 3:
assert(((Addend & 0x7) == 0) && "64-bit LDR/STR not 8-byte aligned.");
break;
}
}
// Compensate for implicit shift.
Addend >>= ImplicitShift;
assert(isUInt<12>(Addend) && "Addend cannot be encoded.");
// Encode the addend into the instruction.
*p = (*p & 0xFFC003FF) | ((uint32_t)(Addend << 10) & 0x003FFC00);
break;
}
}
}
relocation_iterator
processRelocationRef(unsigned SectionID, relocation_iterator RelI,
ObjectImage &ObjImg, ObjSectionToIDMap &ObjSectionToID,
const SymbolTableMap &Symbols, StubMap &Stubs) override {
const MachOObjectFile &Obj =
static_cast<const MachOObjectFile &>(*ObjImg.getObjectFile());
MachO::any_relocation_info RelInfo =
Obj.getRelocation(RelI->getRawDataRefImpl());
assert(!Obj.isRelocationScattered(RelInfo) && "");
// ARM64 has an ARM64_RELOC_ADDEND relocation type that carries an explicit
// addend for the following relocation. If found: (1) store the associated
// addend, (2) consume the next relocation, and (3) use the stored addend to
// override the addend.
int64_t ExplicitAddend = 0;
if (Obj.getAnyRelocationType(RelInfo) == MachO::ARM64_RELOC_ADDEND) {
assert(!Obj.getPlainRelocationExternal(RelInfo));
assert(!Obj.getAnyRelocationPCRel(RelInfo));
assert(Obj.getAnyRelocationLength(RelInfo) == 2);
int64_t RawAddend = Obj.getPlainRelocationSymbolNum(RelInfo);
// Sign-extend the 24-bit to 64-bit.
ExplicitAddend = SignExtend64(RawAddend, 24);
++RelI;
RelInfo = Obj.getRelocation(RelI->getRawDataRefImpl());
}
RelocationEntry RE(getRelocationEntry(SectionID, ObjImg, RelI));
RE.Addend = decodeAddend(RE);
RelocationValueRef Value(
getRelocationValueRef(ObjImg, RelI, RE, ObjSectionToID, Symbols));
assert((ExplicitAddend == 0 || RE.Addend == 0) && "Relocation has "\
"ARM64_RELOC_ADDEND and embedded addend in the instruction.");
if (ExplicitAddend) {
RE.Addend = ExplicitAddend;
Value.Offset = ExplicitAddend;
}
bool IsExtern = Obj.getPlainRelocationExternal(RelInfo);
if (!IsExtern && RE.IsPCRel)
makeValueAddendPCRel(Value, ObjImg, RelI, 1 << RE.Size);
RE.Addend = Value.Offset;
if (RE.RelType == MachO::ARM64_RELOC_GOT_LOAD_PAGE21 ||
RE.RelType == MachO::ARM64_RELOC_GOT_LOAD_PAGEOFF12)
processGOTRelocation(RE, Value, Stubs);
else {
if (Value.SymbolName)
addRelocationForSymbol(RE, Value.SymbolName);
else
addRelocationForSection(RE, Value.SectionID);
}
return ++RelI;
}
void resolveRelocation(const RelocationEntry &RE, uint64_t Value) override {
DEBUG(dumpRelocationToResolve(RE, Value));
const SectionEntry &Section = Sections[RE.SectionID];
uint8_t *LocalAddress = Section.Address + RE.Offset;
MachO::RelocationInfoType RelType =
static_cast<MachO::RelocationInfoType>(RE.RelType);
switch (RelType) {
default:
llvm_unreachable("Invalid relocation type!");
case MachO::ARM64_RELOC_UNSIGNED: {
assert(!RE.IsPCRel && "PCRel and ARM64_RELOC_UNSIGNED not supported");
// 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).
if (RE.Size < 2)
llvm_unreachable("Invalid size for ARM64_RELOC_UNSIGNED");
encodeAddend(LocalAddress, 1 << RE.Size, RelType, Value + RE.Addend);
break;
}
case MachO::ARM64_RELOC_BRANCH26: {
assert(RE.IsPCRel && "not PCRel and ARM64_RELOC_BRANCH26 not supported");
// Check if branch is in range.
uint64_t FinalAddress = Section.LoadAddress + RE.Offset;
int64_t PCRelVal = Value - FinalAddress + RE.Addend;
encodeAddend(LocalAddress, /*Size=*/4, RelType, PCRelVal);
break;
}
case MachO::ARM64_RELOC_GOT_LOAD_PAGE21:
case MachO::ARM64_RELOC_PAGE21: {
assert(RE.IsPCRel && "not PCRel and ARM64_RELOC_PAGE21 not supported");
// Adjust for PC-relative relocation and offset.
uint64_t FinalAddress = Section.LoadAddress + RE.Offset;
int64_t PCRelVal =
((Value + RE.Addend) & (-4096)) - (FinalAddress & (-4096));
encodeAddend(LocalAddress, /*Size=*/4, RelType, PCRelVal);
break;
}
case MachO::ARM64_RELOC_GOT_LOAD_PAGEOFF12:
case MachO::ARM64_RELOC_PAGEOFF12: {
assert(!RE.IsPCRel && "PCRel and ARM64_RELOC_PAGEOFF21 not supported");
// Add the offset from the symbol.
Value += RE.Addend;
// Mask out the page address and only use the lower 12 bits.
Value &= 0xFFF;
encodeAddend(LocalAddress, /*Size=*/4, RelType, Value);
break;
}
case MachO::ARM64_RELOC_SUBTRACTOR:
case MachO::ARM64_RELOC_POINTER_TO_GOT:
case MachO::ARM64_RELOC_TLVP_LOAD_PAGE21:
case MachO::ARM64_RELOC_TLVP_LOAD_PAGEOFF12:
llvm_unreachable("Relocation type not yet implemented!");
case MachO::ARM64_RELOC_ADDEND:
llvm_unreachable("ARM64_RELOC_ADDEND should have been handeled by "
"processRelocationRef!");
}
}
void finalizeSection(ObjectImage &ObjImg, unsigned SectionID,
const SectionRef &Section) {}
private:
void processGOTRelocation(const RelocationEntry &RE,
RelocationValueRef &Value, StubMap &Stubs) {
assert(RE.Size == 2);
SectionEntry &Section = Sections[RE.SectionID];
StubMap::const_iterator i = Stubs.find(Value);
uintptr_t Addr;
if (i != Stubs.end())
Addr = reinterpret_cast<uintptr_t>(Section.Address) + i->second;
else {
// FIXME: There must be a better way to do this then to check and fix the
// alignment every time!!!
uintptr_t BaseAddress = uintptr_t(Section.Address);
uintptr_t StubAlignment = getStubAlignment();
uintptr_t StubAddress =
(BaseAddress + Section.StubOffset + StubAlignment - 1) &
-StubAlignment;
unsigned StubOffset = StubAddress - BaseAddress;
Stubs[Value] = StubOffset;
assert(((StubAddress % getStubAlignment()) == 0) &&
"GOT entry not aligned");
RelocationEntry GOTRE(RE.SectionID, StubOffset,
MachO::ARM64_RELOC_UNSIGNED, Value.Offset,
/*IsPCRel=*/false, /*Size=*/3);
if (Value.SymbolName)
addRelocationForSymbol(GOTRE, Value.SymbolName);
else
addRelocationForSection(GOTRE, Value.SectionID);
Section.StubOffset = StubOffset + getMaxStubSize();
Addr = StubAddress;
}
RelocationEntry TargetRE(RE.SectionID, RE.Offset, RE.RelType, /*Addend=*/0,
RE.IsPCRel, RE.Size);
resolveRelocation(TargetRE, static_cast<uint64_t>(Addr));
}
};
}
#undef DEBUG_TYPE
#endif