| //=== aarch64.h - Generic JITLink aarch64 edge kinds, utilities -*- 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 |
| // |
| //===----------------------------------------------------------------------===// |
| // |
| // Generic utilities for graphs representing aarch64 objects. |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #ifndef LLVM_EXECUTIONENGINE_JITLINK_AARCH64_H |
| #define LLVM_EXECUTIONENGINE_JITLINK_AARCH64_H |
| |
| #include "TableManager.h" |
| #include "llvm/ExecutionEngine/JITLink/JITLink.h" |
| #include "llvm/ExecutionEngine/JITLink/MemoryFlags.h" |
| |
| namespace llvm { |
| namespace jitlink { |
| namespace aarch64 { |
| |
| enum EdgeKind_aarch64 : Edge::Kind { |
| Branch26 = Edge::FirstRelocation, |
| Pointer32, |
| Pointer64, |
| Pointer64Anon, |
| Page21, |
| PageOffset12, |
| MoveWide16, |
| GOTPage21, |
| GOTPageOffset12, |
| TLVPage21, |
| TLVPageOffset12, |
| PointerToGOT, |
| PairedAddend, |
| LDRLiteral19, |
| Delta32, |
| Delta64, |
| NegDelta32, |
| NegDelta64, |
| }; |
| |
| /// Returns a string name for the given aarch64 edge. For debugging purposes |
| /// only |
| const char *getEdgeKindName(Edge::Kind K); |
| |
| // Returns whether the Instr is LD/ST (imm12) |
| inline bool isLoadStoreImm12(uint32_t Instr) { |
| constexpr uint32_t LoadStoreImm12Mask = 0x3b000000; |
| return (Instr & LoadStoreImm12Mask) == 0x39000000; |
| } |
| |
| // Returns the amount the address operand of LD/ST (imm12) |
| // should be shifted right by. |
| // |
| // The shift value varies by the data size of LD/ST instruction. |
| // For instance, LDH instructoin needs the address to be shifted |
| // right by 1. |
| inline unsigned getPageOffset12Shift(uint32_t Instr) { |
| constexpr uint32_t Vec128Mask = 0x04800000; |
| |
| if (isLoadStoreImm12(Instr)) { |
| uint32_t ImplicitShift = Instr >> 30; |
| if (ImplicitShift == 0) |
| if ((Instr & Vec128Mask) == Vec128Mask) |
| ImplicitShift = 4; |
| |
| return ImplicitShift; |
| } |
| |
| return 0; |
| } |
| |
| // Returns whether the Instr is MOVK/MOVZ (imm16) with a zero immediate field |
| inline bool isMoveWideImm16(uint32_t Instr) { |
| constexpr uint32_t MoveWideImm16Mask = 0x5f9fffe0; |
| return (Instr & MoveWideImm16Mask) == 0x52800000; |
| } |
| |
| // Returns the amount the address operand of MOVK/MOVZ (imm16) |
| // should be shifted right by. |
| // |
| // The shift value is specfied in the assembly as LSL #<shift>. |
| inline unsigned getMoveWide16Shift(uint32_t Instr) { |
| if (isMoveWideImm16(Instr)) { |
| uint32_t ImplicitShift = (Instr >> 21) & 0b11; |
| return ImplicitShift << 4; |
| } |
| |
| return 0; |
| } |
| |
| /// Apply fixup expression for edge to block content. |
| inline Error applyFixup(LinkGraph &G, Block &B, const Edge &E) { |
| using namespace support; |
| |
| char *BlockWorkingMem = B.getAlreadyMutableContent().data(); |
| char *FixupPtr = BlockWorkingMem + E.getOffset(); |
| orc::ExecutorAddr FixupAddress = B.getAddress() + E.getOffset(); |
| |
| switch (E.getKind()) { |
| case Branch26: { |
| assert((FixupAddress.getValue() & 0x3) == 0 && |
| "Branch-inst is not 32-bit aligned"); |
| |
| int64_t Value = E.getTarget().getAddress() - FixupAddress + E.getAddend(); |
| |
| if (static_cast<uint64_t>(Value) & 0x3) |
| return make_error<JITLinkError>("Branch26 target is not 32-bit " |
| "aligned"); |
| |
| if (Value < -(1 << 27) || Value > ((1 << 27) - 1)) |
| return makeTargetOutOfRangeError(G, B, E); |
| |
| uint32_t RawInstr = *(little32_t *)FixupPtr; |
| assert((RawInstr & 0x7fffffff) == 0x14000000 && |
| "RawInstr isn't a B or BR immediate instruction"); |
| uint32_t Imm = (static_cast<uint32_t>(Value) & ((1 << 28) - 1)) >> 2; |
| uint32_t FixedInstr = RawInstr | Imm; |
| *(little32_t *)FixupPtr = FixedInstr; |
| break; |
| } |
| case Pointer32: { |
| uint64_t Value = E.getTarget().getAddress().getValue() + E.getAddend(); |
| if (Value > std::numeric_limits<uint32_t>::max()) |
| return makeTargetOutOfRangeError(G, B, E); |
| *(ulittle32_t *)FixupPtr = Value; |
| break; |
| } |
| case Pointer64: |
| case Pointer64Anon: { |
| uint64_t Value = E.getTarget().getAddress().getValue() + E.getAddend(); |
| *(ulittle64_t *)FixupPtr = Value; |
| break; |
| } |
| case Page21: { |
| assert((E.getKind() != GOTPage21 || E.getAddend() == 0) && |
| "GOTPAGE21 with non-zero addend"); |
| uint64_t TargetPage = |
| (E.getTarget().getAddress().getValue() + E.getAddend()) & |
| ~static_cast<uint64_t>(4096 - 1); |
| uint64_t PCPage = |
| FixupAddress.getValue() & ~static_cast<uint64_t>(4096 - 1); |
| |
| int64_t PageDelta = TargetPage - PCPage; |
| if (!isInt<33>(PageDelta)) |
| return makeTargetOutOfRangeError(G, B, E); |
| |
| uint32_t RawInstr = *(ulittle32_t *)FixupPtr; |
| assert((RawInstr & 0xffffffe0) == 0x90000000 && |
| "RawInstr isn't an ADRP instruction"); |
| uint32_t ImmLo = (static_cast<uint64_t>(PageDelta) >> 12) & 0x3; |
| uint32_t ImmHi = (static_cast<uint64_t>(PageDelta) >> 14) & 0x7ffff; |
| uint32_t FixedInstr = RawInstr | (ImmLo << 29) | (ImmHi << 5); |
| *(ulittle32_t *)FixupPtr = FixedInstr; |
| break; |
| } |
| case PageOffset12: { |
| uint64_t TargetOffset = |
| (E.getTarget().getAddress() + E.getAddend()).getValue() & 0xfff; |
| |
| uint32_t RawInstr = *(ulittle32_t *)FixupPtr; |
| unsigned ImmShift = getPageOffset12Shift(RawInstr); |
| |
| if (TargetOffset & ((1 << ImmShift) - 1)) |
| return make_error<JITLinkError>("PAGEOFF12 target is not aligned"); |
| |
| uint32_t EncodedImm = (TargetOffset >> ImmShift) << 10; |
| uint32_t FixedInstr = RawInstr | EncodedImm; |
| *(ulittle32_t *)FixupPtr = FixedInstr; |
| break; |
| } |
| case MoveWide16: { |
| uint64_t TargetOffset = |
| (E.getTarget().getAddress() + E.getAddend()).getValue(); |
| |
| uint32_t RawInstr = *(ulittle32_t *)FixupPtr; |
| assert(isMoveWideImm16(RawInstr) && |
| "RawInstr isn't a MOVK/MOVZ instruction"); |
| |
| unsigned ImmShift = getMoveWide16Shift(RawInstr); |
| uint32_t Imm = (TargetOffset >> ImmShift) & 0xffff; |
| uint32_t FixedInstr = RawInstr | (Imm << 5); |
| *(ulittle32_t *)FixupPtr = FixedInstr; |
| break; |
| } |
| case LDRLiteral19: { |
| assert((FixupAddress.getValue() & 0x3) == 0 && "LDR is not 32-bit aligned"); |
| assert(E.getAddend() == 0 && "LDRLiteral19 with non-zero addend"); |
| uint32_t RawInstr = *(ulittle32_t *)FixupPtr; |
| assert(RawInstr == 0x58000010 && "RawInstr isn't a 64-bit LDR literal"); |
| int64_t Delta = E.getTarget().getAddress() - FixupAddress; |
| if (Delta & 0x3) |
| return make_error<JITLinkError>("LDR literal target is not 32-bit " |
| "aligned"); |
| if (Delta < -(1 << 20) || Delta > ((1 << 20) - 1)) |
| return makeTargetOutOfRangeError(G, B, E); |
| |
| uint32_t EncodedImm = ((static_cast<uint32_t>(Delta) >> 2) & 0x7ffff) << 5; |
| uint32_t FixedInstr = RawInstr | EncodedImm; |
| *(ulittle32_t *)FixupPtr = FixedInstr; |
| break; |
| } |
| case Delta32: |
| case Delta64: |
| case NegDelta32: |
| case NegDelta64: { |
| int64_t Value; |
| if (E.getKind() == Delta32 || E.getKind() == Delta64) |
| Value = E.getTarget().getAddress() - FixupAddress + E.getAddend(); |
| else |
| Value = FixupAddress - E.getTarget().getAddress() + E.getAddend(); |
| |
| if (E.getKind() == Delta32 || E.getKind() == NegDelta32) { |
| if (Value < std::numeric_limits<int32_t>::min() || |
| Value > std::numeric_limits<int32_t>::max()) |
| return makeTargetOutOfRangeError(G, B, E); |
| *(little32_t *)FixupPtr = Value; |
| } else |
| *(little64_t *)FixupPtr = Value; |
| break; |
| } |
| case TLVPage21: |
| case GOTPage21: |
| case TLVPageOffset12: |
| case GOTPageOffset12: |
| case PointerToGOT: { |
| return make_error<JITLinkError>( |
| "In graph " + G.getName() + ", section " + B.getSection().getName() + |
| "GOT/TLV edge kinds not lowered: " + getEdgeKindName(E.getKind())); |
| } |
| default: |
| return make_error<JITLinkError>( |
| "In graph " + G.getName() + ", section " + B.getSection().getName() + |
| "unsupported edge kind" + getEdgeKindName(E.getKind())); |
| } |
| |
| return Error::success(); |
| } |
| |
| /// AArch64 null pointer content. |
| extern const uint8_t NullGOTEntryContent[8]; |
| |
| /// AArch64 PLT stub content. |
| extern const uint8_t StubContent[8]; |
| |
| /// Global Offset Table Builder. |
| class GOTTableManager : public TableManager<GOTTableManager> { |
| public: |
| static StringRef getSectionName() { return "$__GOT"; } |
| |
| bool visitEdge(LinkGraph &G, Block *B, Edge &E) { |
| Edge::Kind KindToSet = Edge::Invalid; |
| const char *BlockWorkingMem = B->getContent().data(); |
| const char *FixupPtr = BlockWorkingMem + E.getOffset(); |
| |
| switch (E.getKind()) { |
| case aarch64::GOTPage21: |
| case aarch64::TLVPage21: { |
| KindToSet = aarch64::Page21; |
| break; |
| } |
| case aarch64::GOTPageOffset12: |
| case aarch64::TLVPageOffset12: { |
| KindToSet = aarch64::PageOffset12; |
| uint32_t RawInstr = *(const support::ulittle32_t *)FixupPtr; |
| (void)RawInstr; |
| assert(E.getAddend() == 0 && |
| "GOTPageOffset12/TLVPageOffset12 with non-zero addend"); |
| assert((RawInstr & 0xfffffc00) == 0xf9400000 && |
| "RawInstr isn't a 64-bit LDR immediate"); |
| break; |
| } |
| case aarch64::PointerToGOT: { |
| KindToSet = aarch64::Delta64; |
| break; |
| } |
| default: |
| return false; |
| } |
| assert(KindToSet != Edge::Invalid && |
| "Fell through switch, but no new kind to set"); |
| DEBUG_WITH_TYPE("jitlink", { |
| dbgs() << " Fixing " << G.getEdgeKindName(E.getKind()) << " edge at " |
| << B->getFixupAddress(E) << " (" << B->getAddress() << " + " |
| << formatv("{0:x}", E.getOffset()) << ")\n"; |
| }); |
| E.setKind(KindToSet); |
| E.setTarget(getEntryForTarget(G, E.getTarget())); |
| return true; |
| } |
| |
| Symbol &createEntry(LinkGraph &G, Symbol &Target) { |
| auto &GOTEntryBlock = G.createContentBlock( |
| getGOTSection(G), getGOTEntryBlockContent(), orc::ExecutorAddr(), 8, 0); |
| GOTEntryBlock.addEdge(aarch64::Pointer64, 0, Target, 0); |
| return G.addAnonymousSymbol(GOTEntryBlock, 0, 8, false, false); |
| } |
| |
| private: |
| Section &getGOTSection(LinkGraph &G) { |
| if (!GOTSection) |
| GOTSection = |
| &G.createSection(getSectionName(), MemProt::Read | MemProt::Exec); |
| return *GOTSection; |
| } |
| |
| ArrayRef<char> getGOTEntryBlockContent() { |
| return {reinterpret_cast<const char *>(NullGOTEntryContent), |
| sizeof(NullGOTEntryContent)}; |
| } |
| |
| Section *GOTSection = nullptr; |
| }; |
| |
| /// Procedure Linkage Table Builder. |
| class PLTTableManager : public TableManager<PLTTableManager> { |
| public: |
| PLTTableManager(GOTTableManager &GOT) : GOT(GOT) {} |
| |
| static StringRef getSectionName() { return "$__STUBS"; } |
| |
| bool visitEdge(LinkGraph &G, Block *B, Edge &E) { |
| if (E.getKind() == aarch64::Branch26 && !E.getTarget().isDefined()) { |
| DEBUG_WITH_TYPE("jitlink", { |
| dbgs() << " Fixing " << G.getEdgeKindName(E.getKind()) << " edge at " |
| << B->getFixupAddress(E) << " (" << B->getAddress() << " + " |
| << formatv("{0:x}", E.getOffset()) << ")\n"; |
| }); |
| E.setTarget(getEntryForTarget(G, E.getTarget())); |
| return true; |
| } |
| return false; |
| } |
| |
| Symbol &createEntry(LinkGraph &G, Symbol &Target) { |
| auto &StubContentBlock = G.createContentBlock( |
| getStubsSection(G), getStubBlockContent(), orc::ExecutorAddr(), 1, 0); |
| // Re-use GOT entries for stub targets. |
| auto &GOTEntrySymbol = GOT.getEntryForTarget(G, Target); |
| StubContentBlock.addEdge(aarch64::LDRLiteral19, 0, GOTEntrySymbol, 0); |
| return G.addAnonymousSymbol(StubContentBlock, 0, 8, true, false); |
| } |
| |
| public: |
| Section &getStubsSection(LinkGraph &G) { |
| if (!StubsSection) |
| StubsSection = |
| &G.createSection(getSectionName(), MemProt::Read | MemProt::Exec); |
| return *StubsSection; |
| } |
| |
| ArrayRef<char> getStubBlockContent() { |
| return {reinterpret_cast<const char *>(StubContent), sizeof(StubContent)}; |
| } |
| |
| GOTTableManager &GOT; |
| Section *StubsSection = nullptr; |
| }; |
| |
| } // namespace aarch64 |
| } // namespace jitlink |
| } // namespace llvm |
| |
| #endif // LLVM_EXECUTIONENGINE_JITLINK_AARCH64_H |