1 //===- ARM64_32.cpp 2 //----------------------------------------------------------===// 3 // 4 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 5 // See https://llvm.org/LICENSE.txt for license information. 6 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 7 // 8 //===----------------------------------------------------------------------===// 9 10 #include "Arch/ARM64Common.h" 11 #include "InputFiles.h" 12 #include "Symbols.h" 13 #include "SyntheticSections.h" 14 #include "Target.h" 15 16 #include "lld/Common/ErrorHandler.h" 17 #include "llvm/ADT/SmallVector.h" 18 #include "llvm/ADT/StringRef.h" 19 #include "llvm/BinaryFormat/MachO.h" 20 #include "llvm/Support/Endian.h" 21 #include "llvm/Support/MathExtras.h" 22 23 using namespace llvm::MachO; 24 using namespace llvm::support::endian; 25 using namespace lld; 26 using namespace lld::macho; 27 28 namespace { 29 30 struct ARM64_32 : ARM64Common { 31 ARM64_32(); 32 void writeStub(uint8_t *buf, const Symbol &) const override; 33 void writeStubHelperHeader(uint8_t *buf) const override; 34 void writeStubHelperEntry(uint8_t *buf, const DylibSymbol &, 35 uint64_t entryAddr) const override; 36 const RelocAttrs &getRelocAttrs(uint8_t type) const override; 37 }; 38 39 } // namespace 40 41 // These are very similar to ARM64's relocation attributes, except that we don't 42 // have the BYTE8 flag set. 43 const RelocAttrs &ARM64_32::getRelocAttrs(uint8_t type) const { 44 static const std::array<RelocAttrs, 11> relocAttrsArray{{ 45 #define B(x) RelocAttrBits::x 46 {"UNSIGNED", B(UNSIGNED) | B(ABSOLUTE) | B(EXTERN) | B(LOCAL) | B(BYTE4)}, 47 {"SUBTRACTOR", B(SUBTRAHEND) | B(EXTERN) | B(BYTE4)}, 48 {"BRANCH26", B(PCREL) | B(EXTERN) | B(BRANCH) | B(BYTE4)}, 49 {"PAGE21", B(PCREL) | B(EXTERN) | B(BYTE4)}, 50 {"PAGEOFF12", B(ABSOLUTE) | B(EXTERN) | B(BYTE4)}, 51 {"GOT_LOAD_PAGE21", B(PCREL) | B(EXTERN) | B(GOT) | B(BYTE4)}, 52 {"GOT_LOAD_PAGEOFF12", 53 B(ABSOLUTE) | B(EXTERN) | B(GOT) | B(LOAD) | B(BYTE4)}, 54 {"POINTER_TO_GOT", B(PCREL) | B(EXTERN) | B(GOT) | B(POINTER) | B(BYTE4)}, 55 {"TLVP_LOAD_PAGE21", B(PCREL) | B(EXTERN) | B(TLV) | B(BYTE4)}, 56 {"TLVP_LOAD_PAGEOFF12", 57 B(ABSOLUTE) | B(EXTERN) | B(TLV) | B(LOAD) | B(BYTE4)}, 58 {"ADDEND", B(ADDEND)}, 59 #undef B 60 }}; 61 assert(type < relocAttrsArray.size() && "invalid relocation type"); 62 if (type >= relocAttrsArray.size()) 63 return invalidRelocAttrs; 64 return relocAttrsArray[type]; 65 } 66 67 // The stub code is fairly similar to ARM64's, except that we load pointers into 68 // 32-bit 'w' registers, instead of the 64-bit 'x' ones. 69 70 static constexpr uint32_t stubCode[] = { 71 0x90000010, // 00: adrp x16, __la_symbol_ptr@page 72 0xb9400210, // 04: ldr w16, [x16, __la_symbol_ptr@pageoff] 73 0xd61f0200, // 08: br x16 74 }; 75 76 void ARM64_32::writeStub(uint8_t *buf8, const Symbol &sym) const { 77 ::writeStub<ILP32>(buf8, stubCode, sym); 78 } 79 80 static constexpr uint32_t stubHelperHeaderCode[] = { 81 0x90000011, // 00: adrp x17, _dyld_private@page 82 0x91000231, // 04: add x17, x17, _dyld_private@pageoff 83 0xa9bf47f0, // 08: stp x16/x17, [sp, #-16]! 84 0x90000010, // 0c: adrp x16, dyld_stub_binder@page 85 0xb9400210, // 10: ldr w16, [x16, dyld_stub_binder@pageoff] 86 0xd61f0200, // 14: br x16 87 }; 88 89 void ARM64_32::writeStubHelperHeader(uint8_t *buf8) const { 90 ::writeStubHelperHeader<ILP32>(buf8, stubHelperHeaderCode); 91 } 92 93 static constexpr uint32_t stubHelperEntryCode[] = { 94 0x18000050, // 00: ldr w16, l0 95 0x14000000, // 04: b stubHelperHeader 96 0x00000000, // 08: l0: .long 0 97 }; 98 99 void ARM64_32::writeStubHelperEntry(uint8_t *buf8, const DylibSymbol &sym, 100 uint64_t entryVA) const { 101 ::writeStubHelperEntry(buf8, stubHelperEntryCode, sym, entryVA); 102 } 103 104 ARM64_32::ARM64_32() : ARM64Common(ILP32()) { 105 cpuType = CPU_TYPE_ARM64_32; 106 cpuSubtype = CPU_SUBTYPE_ARM64_V8; 107 108 stubSize = sizeof(stubCode); 109 stubHelperHeaderSize = sizeof(stubHelperHeaderCode); 110 stubHelperEntrySize = sizeof(stubHelperEntryCode); 111 } 112 113 TargetInfo *macho::createARM64_32TargetInfo() { 114 static ARM64_32 t; 115 return &t; 116 } 117