caio/clang-p2996
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity
Files
5a3556aa5563fb89693935303463881df44094de
clang-p2996/llvm/lib/ExecutionEngine/JITLink/MachO_arm64.cpp
Lang Hames 447d3017e4 [JITLink][MachO][arm64] Mask high bits out of immediate for LDRLiteral19. 
Negative deltas for LDRLiteral19 have their high bits set. If these bits aren't
masked out then they will overwrite other instruction bits, leading to a bogus
encoding.

This long-standing relocation bug was exposed by e50aea58d5, "[JITLink][ORC]
Major JITLinkMemoryManager refactor.", which caused memory layouts to be
reordered, which in turn lead to a previously unseen negative delta. (Unseen
because LDRLiteral19s were only created in JITLink passes where they always
pointed at segments that were layed-out-after in the old layout).

No testcase yet: Our existing regression test infrastructure is good at checking
that operand bits are correct, but provides no easy way to test for bad opcode
bits. I'll have a think about the right way to approach this.

https://llvm.org/PR52153
2021-10-12 22:19:47 -07:00

738 lines
26 KiB
C++
Raw Blame History

//===---- MachO_arm64.cpp - JIT linker implementation for MachO/arm64 -----===//
//
// 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
//
//===----------------------------------------------------------------------===//
//
// MachO/arm64 jit-link implementation.
//
//===----------------------------------------------------------------------===//
#include "llvm/ExecutionEngine/JITLink/MachO_arm64.h"
#include "MachOLinkGraphBuilder.h"
#include "PerGraphGOTAndPLTStubsBuilder.h"
#define DEBUG_TYPE "jitlink"
using namespace llvm;
using namespace llvm::jitlink;
using namespace llvm::jitlink::MachO_arm64_Edges;
namespace {
class MachOLinkGraphBuilder_arm64 : public MachOLinkGraphBuilder {
public:
MachOLinkGraphBuilder_arm64(const object::MachOObjectFile &Obj)
: MachOLinkGraphBuilder(Obj, Triple("arm64-apple-darwin"),
getMachOARM64RelocationKindName),
NumSymbols(Obj.getSymtabLoadCommand().nsyms) {}
private:
static Expected<MachOARM64RelocationKind>
getRelocationKind(const MachO::relocation_info &RI) {
switch (RI.r_type) {
case MachO::ARM64_RELOC_UNSIGNED:
if (!RI.r_pcrel) {
if (RI.r_length == 3)
return RI.r_extern ? Pointer64 : Pointer64Anon;
else if (RI.r_length == 2)
return Pointer32;
}
break;
case MachO::ARM64_RELOC_SUBTRACTOR:
// SUBTRACTOR must be non-pc-rel, extern, with length 2 or 3.
// Initially represent SUBTRACTOR relocations with 'Delta<W>'.
// They may be turned into NegDelta<W> by parsePairRelocation.
if (!RI.r_pcrel && RI.r_extern) {
if (RI.r_length == 2)
return Delta32;
else if (RI.r_length == 3)
return Delta64;
}
break;
case MachO::ARM64_RELOC_BRANCH26:
if (RI.r_pcrel && RI.r_extern && RI.r_length == 2)
return Branch26;
break;
case MachO::ARM64_RELOC_PAGE21:
if (RI.r_pcrel && RI.r_extern && RI.r_length == 2)
return Page21;
break;
case MachO::ARM64_RELOC_PAGEOFF12:
if (!RI.r_pcrel && RI.r_extern && RI.r_length == 2)
return PageOffset12;
break;
case MachO::ARM64_RELOC_GOT_LOAD_PAGE21:
if (RI.r_pcrel && RI.r_extern && RI.r_length == 2)
return GOTPage21;
break;
case MachO::ARM64_RELOC_GOT_LOAD_PAGEOFF12:
if (!RI.r_pcrel && RI.r_extern && RI.r_length == 2)
return GOTPageOffset12;
break;
case MachO::ARM64_RELOC_POINTER_TO_GOT:
if (RI.r_pcrel && RI.r_extern && RI.r_length == 2)
return PointerToGOT;
break;
case MachO::ARM64_RELOC_ADDEND:
if (!RI.r_pcrel && !RI.r_extern && RI.r_length == 2)
return PairedAddend;
break;
}
return make_error<JITLinkError>(
"Unsupported arm64 relocation: address=" +
formatv("{0:x8}", RI.r_address) +
", symbolnum=" + formatv("{0:x6}", RI.r_symbolnum) +
", kind=" + formatv("{0:x1}", RI.r_type) +
", pc_rel=" + (RI.r_pcrel ? "true" : "false") +
", extern=" + (RI.r_extern ? "true" : "false") +
", length=" + formatv("{0:d}", RI.r_length));
}
using PairRelocInfo =
std::tuple<MachOARM64RelocationKind, Symbol *, uint64_t>;
// Parses paired SUBTRACTOR/UNSIGNED relocations and, on success,
// returns the edge kind and addend to be used.
Expected<PairRelocInfo>
parsePairRelocation(Block &BlockToFix, Edge::Kind SubtractorKind,
const MachO::relocation_info &SubRI,
JITTargetAddress FixupAddress, const char *FixupContent,
object::relocation_iterator &UnsignedRelItr,
object::relocation_iterator &RelEnd) {
using namespace support;
assert(((SubtractorKind == Delta32 && SubRI.r_length == 2) ||
(SubtractorKind == Delta64 && SubRI.r_length == 3)) &&
"Subtractor kind should match length");
assert(SubRI.r_extern && "SUBTRACTOR reloc symbol should be extern");
assert(!SubRI.r_pcrel && "SUBTRACTOR reloc should not be PCRel");
if (UnsignedRelItr == RelEnd)
return make_error<JITLinkError>("arm64 SUBTRACTOR without paired "
"UNSIGNED relocation");
auto UnsignedRI = getRelocationInfo(UnsignedRelItr);
if (SubRI.r_address != UnsignedRI.r_address)
return make_error<JITLinkError>("arm64 SUBTRACTOR and paired UNSIGNED "
"point to different addresses");
if (SubRI.r_length != UnsignedRI.r_length)
return make_error<JITLinkError>("length of arm64 SUBTRACTOR and paired "
"UNSIGNED reloc must match");
Symbol *FromSymbol;
if (auto FromSymbolOrErr = findSymbolByIndex(SubRI.r_symbolnum))
FromSymbol = FromSymbolOrErr->GraphSymbol;
else
return FromSymbolOrErr.takeError();
// Read the current fixup value.
uint64_t FixupValue = 0;
if (SubRI.r_length == 3)
FixupValue = *(const little64_t *)FixupContent;
else
FixupValue = *(const little32_t *)FixupContent;
// Find 'ToSymbol' using symbol number or address, depending on whether the
// paired UNSIGNED relocation is extern.
Symbol *ToSymbol = nullptr;
if (UnsignedRI.r_extern) {
// Find target symbol by symbol index.
if (auto ToSymbolOrErr = findSymbolByIndex(UnsignedRI.r_symbolnum))
ToSymbol = ToSymbolOrErr->GraphSymbol;
else
return ToSymbolOrErr.takeError();
} else {
auto ToSymbolSec = findSectionByIndex(UnsignedRI.r_symbolnum - 1);
if (!ToSymbolSec)
return ToSymbolSec.takeError();
ToSymbol = getSymbolByAddress(ToSymbolSec->Address);
assert(ToSymbol && "No symbol for section");
FixupValue -= ToSymbol->getAddress();
}
MachOARM64RelocationKind DeltaKind;
Symbol *TargetSymbol;
uint64_t Addend;
if (&BlockToFix == &FromSymbol->getAddressable()) {
TargetSymbol = ToSymbol;
DeltaKind = (SubRI.r_length == 3) ? Delta64 : Delta32;
Addend = FixupValue + (FixupAddress - FromSymbol->getAddress());
// FIXME: handle extern 'from'.
} else if (&BlockToFix == &ToSymbol->getAddressable()) {
TargetSymbol = &*FromSymbol;
DeltaKind = (SubRI.r_length == 3) ? NegDelta64 : NegDelta32;
Addend = FixupValue - (FixupAddress - ToSymbol->getAddress());
} else {
// BlockToFix was neither FromSymbol nor ToSymbol.
return make_error<JITLinkError>("SUBTRACTOR relocation must fix up "
"either 'A' or 'B' (or a symbol in one "
"of their alt-entry groups)");
}
return PairRelocInfo(DeltaKind, TargetSymbol, Addend);
}
Error addRelocations() override {
using namespace support;
auto &Obj = getObject();
LLVM_DEBUG(dbgs() << "Processing relocations:\n");
for (auto &S : Obj.sections()) {
JITTargetAddress SectionAddress = S.getAddress();
// Skip relocations virtual sections.
if (S.isVirtual()) {
if (S.relocation_begin() != S.relocation_end())
return make_error<JITLinkError>("Virtual section contains "
"relocations");
continue;
}
// Skip relocations for debug symbols.
{
auto &NSec =
getSectionByIndex(Obj.getSectionIndex(S.getRawDataRefImpl()));
if (!NSec.GraphSection) {
LLVM_DEBUG({
dbgs() << " Skipping relocations for MachO section "
<< NSec.SegName << "/" << NSec.SectName
<< " which has no associated graph section\n";
});
continue;
}
}
for (auto RelItr = S.relocation_begin(), RelEnd = S.relocation_end();
RelItr != RelEnd; ++RelItr) {
MachO::relocation_info RI = getRelocationInfo(RelItr);
// Sanity check the relocation kind.
auto Kind = getRelocationKind(RI);
if (!Kind)
return Kind.takeError();
// Find the address of the value to fix up.
JITTargetAddress FixupAddress = SectionAddress + (uint32_t)RI.r_address;
LLVM_DEBUG({
auto &NSec =
getSectionByIndex(Obj.getSectionIndex(S.getRawDataRefImpl()));
dbgs() << " " << NSec.SectName << " + "
<< formatv("{0:x8}", RI.r_address) << ":\n";
});
// Find the block that the fixup points to.
Block *BlockToFix = nullptr;
{
auto SymbolToFixOrErr = findSymbolByAddress(FixupAddress);
if (!SymbolToFixOrErr)
return SymbolToFixOrErr.takeError();
BlockToFix = &SymbolToFixOrErr->getBlock();
}
if (FixupAddress + static_cast<JITTargetAddress>(1ULL << RI.r_length) >
BlockToFix->getAddress() + BlockToFix->getContent().size())
return make_error<JITLinkError>(
"Relocation content extends past end of fixup block");
// Get a pointer to the fixup content.
const char *FixupContent = BlockToFix->getContent().data() +
(FixupAddress - BlockToFix->getAddress());
// The target symbol and addend will be populated by the switch below.
Symbol *TargetSymbol = nullptr;
uint64_t Addend = 0;
if (*Kind == PairedAddend) {
// If this is an Addend relocation then process it and move to the
// paired reloc.
Addend = SignExtend64(RI.r_symbolnum, 24);
if (RelItr == RelEnd)
return make_error<JITLinkError>("Unpaired Addend reloc at " +
formatv("{0:x16}", FixupAddress));
++RelItr;
RI = getRelocationInfo(RelItr);
Kind = getRelocationKind(RI);
if (!Kind)
return Kind.takeError();
if (*Kind != Branch26 && *Kind != Page21 && *Kind != PageOffset12)
return make_error<JITLinkError>(
"Invalid relocation pair: Addend + " +
StringRef(getMachOARM64RelocationKindName(*Kind)));
LLVM_DEBUG({
dbgs() << " Addend: value = " << formatv("{0:x6}", Addend)
<< ", pair is " << getMachOARM64RelocationKindName(*Kind)
<< "\n";
});
// Find the address of the value to fix up.
JITTargetAddress PairedFixupAddress =
SectionAddress + (uint32_t)RI.r_address;
if (PairedFixupAddress != FixupAddress)
return make_error<JITLinkError>("Paired relocation points at "
"different target");
}
switch (*Kind) {
case Branch26: {
if (auto TargetSymbolOrErr = findSymbolByIndex(RI.r_symbolnum))
TargetSymbol = TargetSymbolOrErr->GraphSymbol;
else
return TargetSymbolOrErr.takeError();
uint32_t Instr = *(const ulittle32_t *)FixupContent;
if ((Instr & 0x7fffffff) != 0x14000000)
return make_error<JITLinkError>("BRANCH26 target is not a B or BL "
"instruction with a zero addend");
break;
}
case Pointer32:
if (auto TargetSymbolOrErr = findSymbolByIndex(RI.r_symbolnum))
TargetSymbol = TargetSymbolOrErr->GraphSymbol;
else
return TargetSymbolOrErr.takeError();
Addend = *(const ulittle32_t *)FixupContent;
break;
case Pointer64:
if (auto TargetSymbolOrErr = findSymbolByIndex(RI.r_symbolnum))
TargetSymbol = TargetSymbolOrErr->GraphSymbol;
else
return TargetSymbolOrErr.takeError();
Addend = *(const ulittle64_t *)FixupContent;
break;
case Pointer64Anon: {
JITTargetAddress TargetAddress = *(const ulittle64_t *)FixupContent;
if (auto TargetSymbolOrErr = findSymbolByAddress(TargetAddress))
TargetSymbol = &*TargetSymbolOrErr;
else
return TargetSymbolOrErr.takeError();
Addend = TargetAddress - TargetSymbol->getAddress();
break;
}
case Page21:
case GOTPage21: {
if (auto TargetSymbolOrErr = findSymbolByIndex(RI.r_symbolnum))
TargetSymbol = TargetSymbolOrErr->GraphSymbol;
else
return TargetSymbolOrErr.takeError();
uint32_t Instr = *(const ulittle32_t *)FixupContent;
if ((Instr & 0xffffffe0) != 0x90000000)
return make_error<JITLinkError>("PAGE21/GOTPAGE21 target is not an "
"ADRP instruction with a zero "
"addend");
break;
}
case PageOffset12: {
if (auto TargetSymbolOrErr = findSymbolByIndex(RI.r_symbolnum))
TargetSymbol = TargetSymbolOrErr->GraphSymbol;
else
return TargetSymbolOrErr.takeError();
uint32_t Instr = *(const ulittle32_t *)FixupContent;
uint32_t EncodedAddend = (Instr & 0x003FFC00) >> 10;
if (EncodedAddend != 0)
return make_error<JITLinkError>("GOTPAGEOFF12 target has non-zero "
"encoded addend");
break;
}
case GOTPageOffset12: {
if (auto TargetSymbolOrErr = findSymbolByIndex(RI.r_symbolnum))
TargetSymbol = TargetSymbolOrErr->GraphSymbol;
else
return TargetSymbolOrErr.takeError();
uint32_t Instr = *(const ulittle32_t *)FixupContent;
if ((Instr & 0xfffffc00) != 0xf9400000)
return make_error<JITLinkError>("GOTPAGEOFF12 target is not an LDR "
"immediate instruction with a zero "
"addend");
break;
}
case PointerToGOT:
if (auto TargetSymbolOrErr = findSymbolByIndex(RI.r_symbolnum))
TargetSymbol = TargetSymbolOrErr->GraphSymbol;
else
return TargetSymbolOrErr.takeError();
break;
case Delta32:
case Delta64: {
// We use Delta32/Delta64 to represent SUBTRACTOR relocations.
// parsePairRelocation handles the paired reloc, and returns the
// edge kind to be used (either Delta32/Delta64, or
// NegDelta32/NegDelta64, depending on the direction of the
// subtraction) along with the addend.
auto PairInfo =
parsePairRelocation(*BlockToFix, *Kind, RI, FixupAddress,
FixupContent, ++RelItr, RelEnd);
if (!PairInfo)
return PairInfo.takeError();
std::tie(*Kind, TargetSymbol, Addend) = *PairInfo;
assert(TargetSymbol && "No target symbol from parsePairRelocation?");
break;
}
default:
llvm_unreachable("Special relocation kind should not appear in "
"mach-o file");
}
LLVM_DEBUG({
dbgs() << " ";
Edge GE(*Kind, FixupAddress - BlockToFix->getAddress(), *TargetSymbol,
Addend);
printEdge(dbgs(), *BlockToFix, GE,
getMachOARM64RelocationKindName(*Kind));
dbgs() << "\n";
});
BlockToFix->addEdge(*Kind, FixupAddress - BlockToFix->getAddress(),
*TargetSymbol, Addend);
}
}
return Error::success();
}
unsigned NumSymbols = 0;
};
class PerGraphGOTAndPLTStubsBuilder_MachO_arm64
: public PerGraphGOTAndPLTStubsBuilder<
PerGraphGOTAndPLTStubsBuilder_MachO_arm64> {
public:
using PerGraphGOTAndPLTStubsBuilder<
PerGraphGOTAndPLTStubsBuilder_MachO_arm64>::PerGraphGOTAndPLTStubsBuilder;
bool isGOTEdgeToFix(Edge &E) const {
return E.getKind() == GOTPage21 || E.getKind() == GOTPageOffset12 ||
E.getKind() == PointerToGOT;
}
Symbol &createGOTEntry(Symbol &Target) {
auto &GOTEntryBlock = G.createContentBlock(
getGOTSection(), getGOTEntryBlockContent(), 0, 8, 0);
GOTEntryBlock.addEdge(Pointer64, 0, Target, 0);
return G.addAnonymousSymbol(GOTEntryBlock, 0, 8, false, false);
}
void fixGOTEdge(Edge &E, Symbol &GOTEntry) {
if (E.getKind() == GOTPage21 || E.getKind() == GOTPageOffset12) {
// Update the target, but leave the edge addend as-is.
E.setTarget(GOTEntry);
} else if (E.getKind() == PointerToGOT) {
E.setTarget(GOTEntry);
E.setKind(Delta32);
} else
llvm_unreachable("Not a GOT edge?");
}
bool isExternalBranchEdge(Edge &E) {
return E.getKind() == Branch26 && !E.getTarget().isDefined();
}
Symbol &createPLTStub(Symbol &Target) {
auto &StubContentBlock =
G.createContentBlock(getStubsSection(), getStubBlockContent(), 0, 1, 0);
// Re-use GOT entries for stub targets.
auto &GOTEntrySymbol = getGOTEntry(Target);
StubContentBlock.addEdge(LDRLiteral19, 0, GOTEntrySymbol, 0);
return G.addAnonymousSymbol(StubContentBlock, 0, 8, true, false);
}
void fixPLTEdge(Edge &E, Symbol &Stub) {
assert(E.getKind() == Branch26 && "Not a Branch32 edge?");
assert(E.getAddend() == 0 && "Branch32 edge has non-zero addend?");
E.setTarget(Stub);
}
private:
Section &getGOTSection() {
if (!GOTSection)
GOTSection = &G.createSection("$__GOT", MemProt::Read);
return *GOTSection;
}
Section &getStubsSection() {
if (!StubsSection)
StubsSection =
&G.createSection("$__STUBS", MemProt::Read | MemProt::Exec);
return *StubsSection;
}
ArrayRef<char> getGOTEntryBlockContent() {
return {reinterpret_cast<const char *>(NullGOTEntryContent),
sizeof(NullGOTEntryContent)};
}
ArrayRef<char> getStubBlockContent() {
return {reinterpret_cast<const char *>(StubContent), sizeof(StubContent)};
}
static const uint8_t NullGOTEntryContent[8];
static const uint8_t StubContent[8];
Section *GOTSection = nullptr;
Section *StubsSection = nullptr;
};
const uint8_t
PerGraphGOTAndPLTStubsBuilder_MachO_arm64::NullGOTEntryContent[8] = {
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00};
const uint8_t PerGraphGOTAndPLTStubsBuilder_MachO_arm64::StubContent[8] = {
0x10, 0x00, 0x00, 0x58, // LDR x16, <literal>
0x00, 0x02, 0x1f, 0xd6 // BR x16
};
} // namespace
namespace llvm {
namespace jitlink {
class MachOJITLinker_arm64 : public JITLinker<MachOJITLinker_arm64> {
friend class JITLinker<MachOJITLinker_arm64>;
public:
MachOJITLinker_arm64(std::unique_ptr<JITLinkContext> Ctx,
std::unique_ptr<LinkGraph> G,
PassConfiguration PassConfig)
: JITLinker(std::move(Ctx), std::move(G), std::move(PassConfig)) {}
private:
static unsigned getPageOffset12Shift(uint32_t Instr) {
constexpr uint32_t LoadStoreImm12Mask = 0x3b000000;
constexpr uint32_t Vec128Mask = 0x04800000;
if ((Instr & LoadStoreImm12Mask) == 0x39000000) {
uint32_t ImplicitShift = Instr >> 30;
if (ImplicitShift == 0)
if ((Instr & Vec128Mask) == Vec128Mask)
ImplicitShift = 4;
return ImplicitShift;
}
return 0;
}
Error applyFixup(LinkGraph &G, Block &B, const Edge &E) const {
using namespace support;
char *BlockWorkingMem = B.getAlreadyMutableContent().data();
char *FixupPtr = BlockWorkingMem + E.getOffset();
JITTargetAddress FixupAddress = B.getAddress() + E.getOffset();
switch (E.getKind()) {
case Branch26: {
assert((FixupAddress & 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() + 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() + E.getAddend();
*(ulittle64_t *)FixupPtr = Value;
break;
}
case Page21:
case GOTPage21: {
assert((E.getKind() != GOTPage21 || E.getAddend() == 0) &&
"GOTPAGE21 with non-zero addend");
uint64_t TargetPage =
(E.getTarget().getAddress() + E.getAddend()) &
~static_cast<uint64_t>(4096 - 1);
uint64_t PCPage = FixupAddress & ~static_cast<uint64_t>(4096 - 1);
int64_t PageDelta = TargetPage - PCPage;
if (PageDelta < -(1 << 30) || PageDelta > ((1 << 30) - 1))
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()) & 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 GOTPageOffset12: {
assert(E.getAddend() == 0 && "GOTPAGEOF12 with non-zero addend");
uint32_t RawInstr = *(ulittle32_t *)FixupPtr;
assert((RawInstr & 0xfffffc00) == 0xf9400000 &&
"RawInstr isn't a 64-bit LDR immediate");
uint32_t TargetOffset = E.getTarget().getAddress() & 0xfff;
assert((TargetOffset & 0x7) == 0 && "GOT entry is not 8-byte aligned");
uint32_t EncodedImm = (TargetOffset >> 3) << 10;
uint32_t FixedInstr = RawInstr | EncodedImm;
*(ulittle32_t *)FixupPtr = FixedInstr;
break;
}
case LDRLiteral19: {
assert((FixupAddress & 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;
}
default:
llvm_unreachable("Unrecognized edge kind");
}
return Error::success();
}
uint64_t NullValue = 0;
};
Expected<std::unique_ptr<LinkGraph>>
createLinkGraphFromMachOObject_arm64(MemoryBufferRef ObjectBuffer) {
auto MachOObj = object::ObjectFile::createMachOObjectFile(ObjectBuffer);
if (!MachOObj)
return MachOObj.takeError();
return MachOLinkGraphBuilder_arm64(**MachOObj).buildGraph();
}
void link_MachO_arm64(std::unique_ptr<LinkGraph> G,
std::unique_ptr<JITLinkContext> Ctx) {
PassConfiguration Config;
if (Ctx->shouldAddDefaultTargetPasses(G->getTargetTriple())) {
// Add a mark-live pass.
if (auto MarkLive = Ctx->getMarkLivePass(G->getTargetTriple()))
Config.PrePrunePasses.push_back(std::move(MarkLive));
else
Config.PrePrunePasses.push_back(markAllSymbolsLive);
// Add compact unwind splitter pass.
Config.PrePrunePasses.push_back(
CompactUnwindSplitter("__LD,__compact_unwind"));
// Add an in-place GOT/Stubs pass.
Config.PostPrunePasses.push_back(
PerGraphGOTAndPLTStubsBuilder_MachO_arm64::asPass);
}
if (auto Err = Ctx->modifyPassConfig(*G, Config))
return Ctx->notifyFailed(std::move(Err));
// Construct a JITLinker and run the link function.
MachOJITLinker_arm64::link(std::move(Ctx), std::move(G), std::move(Config));
}
const char *getMachOARM64RelocationKindName(Edge::Kind R) {
switch (R) {
case Branch26:
return "Branch26";
case Pointer64:
return "Pointer64";
case Pointer64Anon:
return "Pointer64Anon";
case Page21:
return "Page21";
case PageOffset12:
return "PageOffset12";
case GOTPage21:
return "GOTPage21";
case GOTPageOffset12:
return "GOTPageOffset12";
case PointerToGOT:
return "PointerToGOT";
case PairedAddend:
return "PairedAddend";
case LDRLiteral19:
return "LDRLiteral19";
case Delta32:
return "Delta32";
case Delta64:
return "Delta64";
case NegDelta32:
return "NegDelta32";
case NegDelta64:
return "NegDelta64";
default:
return getGenericEdgeKindName(static_cast<Edge::Kind>(R));
}
}
} // end namespace jitlink
} // end namespace llvm
Reference in New Issue View Git Blame Copy Permalink