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//===-- RuntimeDyldCOFFAArch64.h --- COFF/AArch64 specific code ---*- C++
//-*-===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// COFF AArch64 support for MC-JIT runtime dynamic linker.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_LIB_EXECUTIONENGINE_RUNTIMEDYLD_TARGETS_RUNTIMEDYLDCOFFAARCH64_H
#define LLVM_LIB_EXECUTIONENGINE_RUNTIMEDYLD_TARGETS_RUNTIMEDYLDCOFFAARCH64_H
#include "../RuntimeDyldCOFF.h"
#include "llvm/BinaryFormat/COFF.h"
#include "llvm/Object/COFF.h"
#include "llvm/Support/Endian.h"
#define DEBUG_TYPE "dyld"
using namespace llvm::support::endian;
namespace llvm {
// This relocation type is used for handling long branch instruction
// throught the Stub.
enum InternalRelocationType : unsigned {
INTERNAL_REL_ARM64_LONG_BRANCH26 = 0x111,
};
static void add16(uint8_t *p, int16_t v) { write16le(p, read16le(p) + v); }
static void or32le(void *P, int32_t V) { write32le(P, read32le(P) | V); }
static void write32AArch64Imm(uint8_t *T, uint64_t imm, uint32_t rangeLimit) {
uint32_t orig = read32le(T);
orig &= ~(0xFFF << 10);
write32le(T, orig | ((imm & (0xFFF >> rangeLimit)) << 10));
}
static void write32AArch64Ldr(uint8_t *T, uint64_t imm) {
uint32_t orig = read32le(T);
uint32_t size = orig >> 30;
// 0x04000000 indicates SIMD/FP registers
// 0x00800000 indicates 128 bit
if ((orig & 0x04800000) == 0x04800000)
size += 4;
if ((imm & ((1 << size) - 1)) != 0)
assert(0 && "misaligned ldr/str offset");
write32AArch64Imm(T, imm >> size, size);
}
static void write32AArch64Addr(void *T, uint64_t s, uint64_t p, int shift) {
uint64_t Imm = (s >> shift) - (p >> shift);
uint32_t ImmLo = (Imm & 0x3) << 29;
uint32_t ImmHi = (Imm & 0x1FFFFC) << 3;
uint64_t Mask = (0x3 << 29) | (0x1FFFFC << 3);
write32le(T, (read32le(T) & ~Mask) | ImmLo | ImmHi);
}
class RuntimeDyldCOFFAArch64 : public RuntimeDyldCOFF {
private:
// When a module is loaded we save the SectionID of the unwind
// sections in a table until we receive a request to register all
// unregisteredEH frame sections with the memory manager.
SmallVector<SID, 2> UnregisteredEHFrameSections;
SmallVector<SID, 2> RegisteredEHFrameSections;
uint64_t ImageBase;
// Fake an __ImageBase pointer by returning the section with the lowest adress
uint64_t getImageBase() {
if (!ImageBase) {
ImageBase = std::numeric_limits<uint64_t>::max();
for (const SectionEntry &Section : Sections)
// The Sections list may contain sections that weren't loaded for
// whatever reason: they may be debug sections, and ProcessAllSections
// is false, or they may be sections that contain 0 bytes. If the
// section isn't loaded, the load address will be 0, and it should not
// be included in the ImageBase calculation.
if (Section.getLoadAddress() != 0)
ImageBase = std::min(ImageBase, Section.getLoadAddress());
}
return ImageBase;
}
public:
RuntimeDyldCOFFAArch64(RuntimeDyld::MemoryManager &MM,
JITSymbolResolver &Resolver)
: RuntimeDyldCOFF(MM, Resolver), ImageBase(0) {}
unsigned getStubAlignment() override { return 8; }
unsigned getMaxStubSize() const override { return 20; }
std::tuple<uint64_t, uint64_t, uint64_t>
generateRelocationStub(unsigned SectionID, StringRef TargetName,
uint64_t Offset, uint64_t RelType, uint64_t Addend,
StubMap &Stubs) {
uintptr_t StubOffset;
SectionEntry &Section = Sections[SectionID];
RelocationValueRef OriginalRelValueRef;
OriginalRelValueRef.SectionID = SectionID;
OriginalRelValueRef.Offset = Offset;
OriginalRelValueRef.Addend = Addend;
OriginalRelValueRef.SymbolName = TargetName.data();
auto Stub = Stubs.find(OriginalRelValueRef);
if (Stub == Stubs.end()) {
LLVM_DEBUG(dbgs() << " Create a new stub function for "
<< TargetName.data() << "\n");
StubOffset = Section.getStubOffset();
Stubs[OriginalRelValueRef] = StubOffset;
createStubFunction(Section.getAddressWithOffset(StubOffset));
Section.advanceStubOffset(getMaxStubSize());
} else {
LLVM_DEBUG(dbgs() << " Stub function found for " << TargetName.data()
<< "\n");
StubOffset = Stub->second;
}
// Resolve original relocation to stub function.
const RelocationEntry RE(SectionID, Offset, RelType, Addend);
resolveRelocation(RE, Section.getLoadAddressWithOffset(StubOffset));
// adjust relocation info so resolution writes to the stub function
// Here an internal relocation type is used for resolving long branch via
// stub instruction.
Addend = 0;
Offset = StubOffset;
RelType = INTERNAL_REL_ARM64_LONG_BRANCH26;
return std::make_tuple(Offset, RelType, Addend);
}
Expected<object::relocation_iterator>
processRelocationRef(unsigned SectionID, object::relocation_iterator RelI,
const object::ObjectFile &Obj,
ObjSectionToIDMap &ObjSectionToID,
StubMap &Stubs) override {
auto Symbol = RelI->getSymbol();
if (Symbol == Obj.symbol_end())
report_fatal_error("Unknown symbol in relocation");
Expected<StringRef> TargetNameOrErr = Symbol->getName();
if (!TargetNameOrErr)
return TargetNameOrErr.takeError();
StringRef TargetName = *TargetNameOrErr;
auto SectionOrErr = Symbol->getSection();
if (!SectionOrErr)
return SectionOrErr.takeError();
auto Section = *SectionOrErr;
uint64_t RelType = RelI->getType();
uint64_t Offset = RelI->getOffset();
// If there is no section, this must be an external reference.
const bool IsExtern = Section == Obj.section_end();
// Determine the Addend used to adjust the relocation value.
uint64_t Addend = 0;
SectionEntry &AddendSection = Sections[SectionID];
uintptr_t ObjTarget = AddendSection.getObjAddress() + Offset;
uint8_t *Displacement = (uint8_t *)ObjTarget;
switch (RelType) {
case COFF::IMAGE_REL_ARM64_ADDR32:
case COFF::IMAGE_REL_ARM64_ADDR32NB:
case COFF::IMAGE_REL_ARM64_REL32:
case COFF::IMAGE_REL_ARM64_SECREL:
Addend = read32le(Displacement);
break;
case COFF::IMAGE_REL_ARM64_BRANCH26: {
uint32_t orig = read32le(Displacement);
Addend = (orig & 0x03FFFFFF) << 2;
if (IsExtern)
std::tie(Offset, RelType, Addend) = generateRelocationStub(
SectionID, TargetName, Offset, RelType, Addend, Stubs);
break;
}
case COFF::IMAGE_REL_ARM64_BRANCH19: {
uint32_t orig = read32le(Displacement);
Addend = (orig & 0x00FFFFE0) >> 3;
break;
}
case COFF::IMAGE_REL_ARM64_BRANCH14: {
uint32_t orig = read32le(Displacement);
Addend = (orig & 0x000FFFE0) >> 3;
break;
}
case COFF::IMAGE_REL_ARM64_REL21:
case COFF::IMAGE_REL_ARM64_PAGEBASE_REL21: {
uint32_t orig = read32le(Displacement);
Addend = ((orig >> 29) & 0x3) | ((orig >> 3) & 0x1FFFFC);
break;
}
case COFF::IMAGE_REL_ARM64_PAGEOFFSET_12L:
case COFF::IMAGE_REL_ARM64_PAGEOFFSET_12A: {
uint32_t orig = read32le(Displacement);
Addend = ((orig >> 10) & 0xFFF);
break;
}
case COFF::IMAGE_REL_ARM64_ADDR64: {
Addend = read64le(Displacement);
break;
}
default:
break;
}
#if !defined(NDEBUG)
SmallString<32> RelTypeName;
RelI->getTypeName(RelTypeName);
LLVM_DEBUG(dbgs() << "\t\tIn Section " << SectionID << " Offset " << Offset
<< " RelType: " << RelTypeName << " TargetName: "
<< TargetName << " Addend " << Addend << "\n");
#endif
unsigned TargetSectionID = -1;
if (IsExtern) {
RelocationEntry RE(SectionID, Offset, RelType, Addend);
addRelocationForSymbol(RE, TargetName);
} else {
if (auto TargetSectionIDOrErr = findOrEmitSection(
Obj, *Section, Section->isText(), ObjSectionToID)) {
TargetSectionID = *TargetSectionIDOrErr;
} else
return TargetSectionIDOrErr.takeError();
uint64_t TargetOffset = getSymbolOffset(*Symbol);
RelocationEntry RE(SectionID, Offset, RelType, TargetOffset + Addend);
addRelocationForSection(RE, TargetSectionID);
}
return ++RelI;
}
void resolveRelocation(const RelocationEntry &RE, uint64_t Value) override {
const auto Section = Sections[RE.SectionID];
uint8_t *Target = Section.getAddressWithOffset(RE.Offset);
uint64_t FinalAddress = Section.getLoadAddressWithOffset(RE.Offset);
switch (RE.RelType) {
default:
llvm_unreachable("unsupported relocation type");
case COFF::IMAGE_REL_ARM64_ABSOLUTE: {
// This relocation is ignored.
break;
}
case COFF::IMAGE_REL_ARM64_PAGEBASE_REL21: {
// The page base of the target, for ADRP instruction.
Value += RE.Addend;
write32AArch64Addr(Target, Value, FinalAddress, 12);
break;
}
case COFF::IMAGE_REL_ARM64_REL21: {
// The 12-bit relative displacement to the target, for instruction ADR
Value += RE.Addend;
write32AArch64Addr(Target, Value, FinalAddress, 0);
break;
}
case COFF::IMAGE_REL_ARM64_PAGEOFFSET_12A: {
// The 12-bit page offset of the target,
// for instructions ADD/ADDS (immediate) with zero shift.
Value += RE.Addend;
write32AArch64Imm(Target, Value & 0xFFF, 0);
break;
}
case COFF::IMAGE_REL_ARM64_PAGEOFFSET_12L: {
// The 12-bit page offset of the target,
// for instruction LDR (indexed, unsigned immediate).
Value += RE.Addend;
write32AArch64Ldr(Target, Value & 0xFFF);
break;
}
case COFF::IMAGE_REL_ARM64_ADDR32: {
// The 32-bit VA of the target.
uint32_t VA = Value + RE.Addend;
write32le(Target, VA);
break;
}
case COFF::IMAGE_REL_ARM64_ADDR32NB: {
// The target's 32-bit RVA.
uint64_t RVA = Value + RE.Addend - getImageBase();
write32le(Target, RVA);
break;
}
case INTERNAL_REL_ARM64_LONG_BRANCH26: {
// Encode the immadiate value for generated Stub instruction (MOVZ)
or32le(Target + 12, ((Value + RE.Addend) & 0xFFFF) << 5);
or32le(Target + 8, ((Value + RE.Addend) & 0xFFFF0000) >> 11);
or32le(Target + 4, ((Value + RE.Addend) & 0xFFFF00000000) >> 27);
or32le(Target + 0, ((Value + RE.Addend) & 0xFFFF000000000000) >> 43);
break;
}
case COFF::IMAGE_REL_ARM64_BRANCH26: {
// The 26-bit relative displacement to the target, for B and BL
// instructions.
uint64_t PCRelVal = Value + RE.Addend - FinalAddress;
assert(isInt<28>(PCRelVal) && "Branch target is out of range.");
write32le(Target, (read32le(Target) & ~(0x03FFFFFF)) |
(PCRelVal & 0x0FFFFFFC) >> 2);
break;
}
case COFF::IMAGE_REL_ARM64_BRANCH19: {
// The 19-bit offset to the relocation target,
// for conditional B instruction.
uint64_t PCRelVal = Value + RE.Addend - FinalAddress;
assert(isInt<21>(PCRelVal) && "Branch target is out of range.");
write32le(Target, (read32le(Target) & ~(0x00FFFFE0)) |
(PCRelVal & 0x001FFFFC) << 3);
break;
}
case COFF::IMAGE_REL_ARM64_BRANCH14: {
// The 14-bit offset to the relocation target,
// for instructions TBZ and TBNZ.
uint64_t PCRelVal = Value + RE.Addend - FinalAddress;
assert(isInt<16>(PCRelVal) && "Branch target is out of range.");
write32le(Target, (read32le(Target) & ~(0x000FFFE0)) |
(PCRelVal & 0x0000FFFC) << 3);
break;
}
case COFF::IMAGE_REL_ARM64_ADDR64: {
// The 64-bit VA of the relocation target.
write64le(Target, Value + RE.Addend);
break;
}
case COFF::IMAGE_REL_ARM64_SECTION: {
// 16-bit section index of the section that contains the target.
assert(static_cast<uint32_t>(RE.SectionID) <= UINT16_MAX &&
"relocation overflow");
add16(Target, RE.SectionID);
break;
}
case COFF::IMAGE_REL_ARM64_SECREL: {
// 32-bit offset of the target from the beginning of its section.
assert(static_cast<int64_t>(RE.Addend) <= INT32_MAX &&
"Relocation overflow");
assert(static_cast<int64_t>(RE.Addend) >= INT32_MIN &&
"Relocation underflow");
write32le(Target, RE.Addend);
break;
}
case COFF::IMAGE_REL_ARM64_REL32: {
// The 32-bit relative address from the byte following the relocation.
uint64_t Result = Value - FinalAddress - 4;
write32le(Target, Result + RE.Addend);
break;
}
}
}
void registerEHFrames() override {}
};
} // End namespace llvm
#endif