206 lines · c
1//===- ARM64Common.h --------------------------------------------*- C++ -*-===//2//3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.4// See https://llvm.org/LICENSE.txt for license information.5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception6//7//===----------------------------------------------------------------------===//8 9#ifndef LLD_MACHO_ARCH_ARM64COMMON_H10#define LLD_MACHO_ARCH_ARM64COMMON_H11 12#include "InputFiles.h"13#include "Symbols.h"14#include "SyntheticSections.h"15#include "Target.h"16 17#include "llvm/BinaryFormat/MachO.h"18 19namespace lld::macho {20 21struct ARM64Common : TargetInfo {22 template <class LP> ARM64Common(LP lp) : TargetInfo(lp) {}23 24 int64_t getEmbeddedAddend(MemoryBufferRef, uint64_t offset,25 const llvm::MachO::relocation_info) const override;26 void relocateOne(uint8_t *loc, const Reloc &, uint64_t va,27 uint64_t pc) const override;28 29 void relaxGotLoad(uint8_t *loc, uint8_t type) const override;30 uint64_t getPageSize() const override { return 16 * 1024; }31 32 void handleDtraceReloc(const Symbol *sym, const Reloc &r,33 uint8_t *loc) const override;34};35 36inline uint64_t bitField(uint64_t value, int right, int width, int left) {37 return ((value >> right) & ((1 << width) - 1)) << left;38}39 40// 25 041// +-----------+---------------------------------------------------+42// | | imm26 |43// +-----------+---------------------------------------------------+44 45inline void encodeBranch26(uint32_t *loc, const Reloc &r, uint32_t base,46 uint64_t va) {47 checkInt(loc, r, va, 28);48 // Since branch destinations are 4-byte aligned, the 2 least-49 // significant bits are 0. They are right shifted off the end.50 llvm::support::endian::write32le(loc, base | bitField(va, 2, 26, 0));51}52 53inline void encodeBranch26(uint32_t *loc, SymbolDiagnostic d, uint32_t base,54 uint64_t va) {55 checkInt(loc, d, va, 28);56 llvm::support::endian::write32le(loc, base | bitField(va, 2, 26, 0));57}58 59// 30 29 23 560// +-+---+---------+-------------------------------------+---------+61// | |ilo| | immhi | |62// +-+---+---------+-------------------------------------+---------+63 64inline void encodePage21(uint32_t *loc, const Reloc &r, uint32_t base,65 uint64_t va) {66 checkInt(loc, r, va, 35);67 llvm::support::endian::write32le(loc, base | bitField(va, 12, 2, 29) |68 bitField(va, 14, 19, 5));69}70 71inline void encodePage21(uint32_t *loc, SymbolDiagnostic d, uint32_t base,72 uint64_t va) {73 checkInt(loc, d, va, 35);74 llvm::support::endian::write32le(loc, base | bitField(va, 12, 2, 29) |75 bitField(va, 14, 19, 5));76}77 78void reportUnalignedLdrStr(void *loc, const Reloc &, uint64_t va, int align);79void reportUnalignedLdrStr(void *loc, SymbolDiagnostic, uint64_t va, int align);80 81// 21 1082// +-------------------+-----------------------+-------------------+83// | | imm12 | |84// +-------------------+-----------------------+-------------------+85 86template <typename Target>87inline void encodePageOff12(uint32_t *loc, Target t, uint32_t base,88 uint64_t va) {89 int scale = 0;90 if ((base & 0x3b00'0000) == 0x3900'0000) { // load/store91 scale = base >> 30;92 if (scale == 0 && (base & 0x0480'0000) == 0x0480'0000) // 128-bit variant93 scale = 4;94 }95 const int size = 1 << scale;96 if ((va & (size - 1)) != 0)97 reportUnalignedLdrStr(loc, t, va, size);98 99 // TODO(gkm): extract embedded addend and warn if != 0100 // uint64_t addend = ((base & 0x003FFC00) >> 10);101 llvm::support::endian::write32le(loc,102 base | bitField(va, scale, 12 - scale, 10));103}104 105inline uint64_t pageBits(uint64_t address) {106 const uint64_t pageMask = ~0xfffull;107 return address & pageMask;108}109 110inline void writeStub(uint8_t *buf8, const uint32_t stubCode[3],111 const macho::Symbol &sym, uint64_t pointerVA) {112 auto *buf32 = reinterpret_cast<uint32_t *>(buf8);113 constexpr size_t stubCodeSize = 3 * sizeof(uint32_t);114 SymbolDiagnostic d = {&sym, "stub"};115 uint64_t pcPageBits =116 pageBits(in.stubs->addr + sym.stubsIndex * stubCodeSize);117 encodePage21(&buf32[0], d, stubCode[0], pageBits(pointerVA) - pcPageBits);118 encodePageOff12(&buf32[1], d, stubCode[1], pointerVA);119 buf32[2] = stubCode[2];120}121 122template <class LP>123inline void writeStubHelperHeader(uint8_t *buf8,124 const uint32_t stubHelperHeaderCode[6]) {125 auto *buf32 = reinterpret_cast<uint32_t *>(buf8);126 auto pcPageBits = [](int i) {127 return pageBits(in.stubHelper->addr + i * sizeof(uint32_t));128 };129 uint64_t loaderVA = in.imageLoaderCache->getVA();130 SymbolDiagnostic d = {nullptr, "stub header helper"};131 encodePage21(&buf32[0], d, stubHelperHeaderCode[0],132 pageBits(loaderVA) - pcPageBits(0));133 encodePageOff12(&buf32[1], d, stubHelperHeaderCode[1], loaderVA);134 buf32[2] = stubHelperHeaderCode[2];135 uint64_t binderVA =136 in.got->addr + in.stubHelper->stubBinder->gotIndex * LP::wordSize;137 encodePage21(&buf32[3], d, stubHelperHeaderCode[3],138 pageBits(binderVA) - pcPageBits(3));139 encodePageOff12(&buf32[4], d, stubHelperHeaderCode[4], binderVA);140 buf32[5] = stubHelperHeaderCode[5];141}142 143inline void writeStubHelperEntry(uint8_t *buf8,144 const uint32_t stubHelperEntryCode[3],145 const Symbol &sym, uint64_t entryVA) {146 auto *buf32 = reinterpret_cast<uint32_t *>(buf8);147 auto pcVA = [entryVA](int i) { return entryVA + i * sizeof(uint32_t); };148 uint64_t stubHelperHeaderVA = in.stubHelper->addr;149 buf32[0] = stubHelperEntryCode[0];150 encodeBranch26(&buf32[1], {&sym, "stub helper"}, stubHelperEntryCode[1],151 stubHelperHeaderVA - pcVA(1));152 buf32[2] = sym.lazyBindOffset;153}154 155template <class LP>156inline void writeObjCMsgSendFastStub(uint8_t *buf,157 const uint32_t objcStubsFastCode[8],158 Symbol *sym, uint64_t stubsAddr,159 uint64_t stubOffset, uint64_t selrefVA,160 uint64_t gotAddr, uint64_t msgSendIndex) {161 SymbolDiagnostic d = {sym, sym->getName()};162 auto *buf32 = reinterpret_cast<uint32_t *>(buf);163 164 auto pcPageBits = [stubsAddr, stubOffset](int i) {165 return pageBits(stubsAddr + stubOffset + i * sizeof(uint32_t));166 };167 168 encodePage21(&buf32[0], d, objcStubsFastCode[0],169 pageBits(selrefVA) - pcPageBits(0));170 encodePageOff12(&buf32[1], d, objcStubsFastCode[1], selrefVA);171 uint64_t gotOffset = msgSendIndex * LP::wordSize;172 encodePage21(&buf32[2], d, objcStubsFastCode[2],173 pageBits(gotAddr + gotOffset) - pcPageBits(2));174 encodePageOff12(&buf32[3], d, objcStubsFastCode[3], gotAddr + gotOffset);175 buf32[4] = objcStubsFastCode[4];176 buf32[5] = objcStubsFastCode[5];177 buf32[6] = objcStubsFastCode[6];178 buf32[7] = objcStubsFastCode[7];179}180 181template <class LP>182inline void183writeObjCMsgSendSmallStub(uint8_t *buf, const uint32_t objcStubsSmallCode[3],184 Symbol *sym, uint64_t stubsAddr, uint64_t stubOffset,185 uint64_t selrefVA, uint64_t msgSendAddr,186 uint64_t msgSendIndex) {187 SymbolDiagnostic d = {sym, sym->getName()};188 auto *buf32 = reinterpret_cast<uint32_t *>(buf);189 190 auto pcPageBits = [stubsAddr, stubOffset](int i) {191 return pageBits(stubsAddr + stubOffset + i * sizeof(uint32_t));192 };193 194 encodePage21(&buf32[0], d, objcStubsSmallCode[0],195 pageBits(selrefVA) - pcPageBits(0));196 encodePageOff12(&buf32[1], d, objcStubsSmallCode[1], selrefVA);197 uint64_t msgSendStubVA = msgSendAddr + msgSendIndex * target->stubSize;198 uint64_t pcVA = stubsAddr + stubOffset + 2 * sizeof(uint32_t);199 encodeBranch26(&buf32[2], {nullptr, "objc_msgSend stub"},200 objcStubsSmallCode[2], msgSendStubVA - pcVA);201}202 203} // namespace lld::macho204 205#endif206