1 //===---- MachO_arm64.cpp - JIT linker implementation for MachO/arm64 -----===//
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-exception
6 //
7 //===----------------------------------------------------------------------===//
8 //
9 // MachO/arm64 jit-link implementation.
10 //
11 //===----------------------------------------------------------------------===//
12
13 #include "llvm/ExecutionEngine/JITLink/MachO_arm64.h"
14
15 #include "MachOLinkGraphBuilder.h"
16 #include "PerGraphGOTAndPLTStubsBuilder.h"
17
18 #define DEBUG_TYPE "jitlink"
19
20 using namespace llvm;
21 using namespace llvm::jitlink;
22 using namespace llvm::jitlink::MachO_arm64_Edges;
23
24 namespace {
25
26 class MachOLinkGraphBuilder_arm64 : public MachOLinkGraphBuilder {
27 public:
MachOLinkGraphBuilder_arm64(const object::MachOObjectFile & Obj)28 MachOLinkGraphBuilder_arm64(const object::MachOObjectFile &Obj)
29 : MachOLinkGraphBuilder(Obj, Triple("arm64-apple-darwin"),
30 getMachOARM64RelocationKindName),
31 NumSymbols(Obj.getSymtabLoadCommand().nsyms) {}
32
33 private:
34 static Expected<MachOARM64RelocationKind>
getRelocationKind(const MachO::relocation_info & RI)35 getRelocationKind(const MachO::relocation_info &RI) {
36 switch (RI.r_type) {
37 case MachO::ARM64_RELOC_UNSIGNED:
38 if (!RI.r_pcrel) {
39 if (RI.r_length == 3)
40 return RI.r_extern ? Pointer64 : Pointer64Anon;
41 else if (RI.r_length == 2)
42 return Pointer32;
43 }
44 break;
45 case MachO::ARM64_RELOC_SUBTRACTOR:
46 // SUBTRACTOR must be non-pc-rel, extern, with length 2 or 3.
47 // Initially represent SUBTRACTOR relocations with 'Delta<W>'.
48 // They may be turned into NegDelta<W> by parsePairRelocation.
49 if (!RI.r_pcrel && RI.r_extern) {
50 if (RI.r_length == 2)
51 return Delta32;
52 else if (RI.r_length == 3)
53 return Delta64;
54 }
55 break;
56 case MachO::ARM64_RELOC_BRANCH26:
57 if (RI.r_pcrel && RI.r_extern && RI.r_length == 2)
58 return Branch26;
59 break;
60 case MachO::ARM64_RELOC_PAGE21:
61 if (RI.r_pcrel && RI.r_extern && RI.r_length == 2)
62 return Page21;
63 break;
64 case MachO::ARM64_RELOC_PAGEOFF12:
65 if (!RI.r_pcrel && RI.r_extern && RI.r_length == 2)
66 return PageOffset12;
67 break;
68 case MachO::ARM64_RELOC_GOT_LOAD_PAGE21:
69 if (RI.r_pcrel && RI.r_extern && RI.r_length == 2)
70 return GOTPage21;
71 break;
72 case MachO::ARM64_RELOC_GOT_LOAD_PAGEOFF12:
73 if (!RI.r_pcrel && RI.r_extern && RI.r_length == 2)
74 return GOTPageOffset12;
75 break;
76 case MachO::ARM64_RELOC_POINTER_TO_GOT:
77 if (RI.r_pcrel && RI.r_extern && RI.r_length == 2)
78 return PointerToGOT;
79 break;
80 case MachO::ARM64_RELOC_ADDEND:
81 if (!RI.r_pcrel && !RI.r_extern && RI.r_length == 2)
82 return PairedAddend;
83 break;
84 }
85
86 return make_error<JITLinkError>(
87 "Unsupported arm64 relocation: address=" +
88 formatv("{0:x8}", RI.r_address) +
89 ", symbolnum=" + formatv("{0:x6}", RI.r_symbolnum) +
90 ", kind=" + formatv("{0:x1}", RI.r_type) +
91 ", pc_rel=" + (RI.r_pcrel ? "true" : "false") +
92 ", extern=" + (RI.r_extern ? "true" : "false") +
93 ", length=" + formatv("{0:d}", RI.r_length));
94 }
95
96 using PairRelocInfo =
97 std::tuple<MachOARM64RelocationKind, Symbol *, uint64_t>;
98
99 // Parses paired SUBTRACTOR/UNSIGNED relocations and, on success,
100 // returns the edge kind and addend to be used.
101 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)102 parsePairRelocation(Block &BlockToFix, Edge::Kind SubtractorKind,
103 const MachO::relocation_info &SubRI,
104 JITTargetAddress FixupAddress, const char *FixupContent,
105 object::relocation_iterator &UnsignedRelItr,
106 object::relocation_iterator &RelEnd) {
107 using namespace support;
108
109 assert(((SubtractorKind == Delta32 && SubRI.r_length == 2) ||
110 (SubtractorKind == Delta64 && SubRI.r_length == 3)) &&
111 "Subtractor kind should match length");
112 assert(SubRI.r_extern && "SUBTRACTOR reloc symbol should be extern");
113 assert(!SubRI.r_pcrel && "SUBTRACTOR reloc should not be PCRel");
114
115 if (UnsignedRelItr == RelEnd)
116 return make_error<JITLinkError>("arm64 SUBTRACTOR without paired "
117 "UNSIGNED relocation");
118
119 auto UnsignedRI = getRelocationInfo(UnsignedRelItr);
120
121 if (SubRI.r_address != UnsignedRI.r_address)
122 return make_error<JITLinkError>("arm64 SUBTRACTOR and paired UNSIGNED "
123 "point to different addresses");
124
125 if (SubRI.r_length != UnsignedRI.r_length)
126 return make_error<JITLinkError>("length of arm64 SUBTRACTOR and paired "
127 "UNSIGNED reloc must match");
128
129 Symbol *FromSymbol;
130 if (auto FromSymbolOrErr = findSymbolByIndex(SubRI.r_symbolnum))
131 FromSymbol = FromSymbolOrErr->GraphSymbol;
132 else
133 return FromSymbolOrErr.takeError();
134
135 // Read the current fixup value.
136 uint64_t FixupValue = 0;
137 if (SubRI.r_length == 3)
138 FixupValue = *(const little64_t *)FixupContent;
139 else
140 FixupValue = *(const little32_t *)FixupContent;
141
142 // Find 'ToSymbol' using symbol number or address, depending on whether the
143 // paired UNSIGNED relocation is extern.
144 Symbol *ToSymbol = nullptr;
145 if (UnsignedRI.r_extern) {
146 // Find target symbol by symbol index.
147 if (auto ToSymbolOrErr = findSymbolByIndex(UnsignedRI.r_symbolnum))
148 ToSymbol = ToSymbolOrErr->GraphSymbol;
149 else
150 return ToSymbolOrErr.takeError();
151 } else {
152 auto ToSymbolSec = findSectionByIndex(UnsignedRI.r_symbolnum - 1);
153 if (!ToSymbolSec)
154 return ToSymbolSec.takeError();
155 ToSymbol = getSymbolByAddress(ToSymbolSec->Address);
156 assert(ToSymbol && "No symbol for section");
157 FixupValue -= ToSymbol->getAddress();
158 }
159
160 MachOARM64RelocationKind DeltaKind;
161 Symbol *TargetSymbol;
162 uint64_t Addend;
163 if (&BlockToFix == &FromSymbol->getAddressable()) {
164 TargetSymbol = ToSymbol;
165 DeltaKind = (SubRI.r_length == 3) ? Delta64 : Delta32;
166 Addend = FixupValue + (FixupAddress - FromSymbol->getAddress());
167 // FIXME: handle extern 'from'.
168 } else if (&BlockToFix == &ToSymbol->getAddressable()) {
169 TargetSymbol = &*FromSymbol;
170 DeltaKind = (SubRI.r_length == 3) ? NegDelta64 : NegDelta32;
171 Addend = FixupValue - (FixupAddress - ToSymbol->getAddress());
172 } else {
173 // BlockToFix was neither FromSymbol nor ToSymbol.
174 return make_error<JITLinkError>("SUBTRACTOR relocation must fix up "
175 "either 'A' or 'B' (or a symbol in one "
176 "of their alt-entry groups)");
177 }
178
179 return PairRelocInfo(DeltaKind, TargetSymbol, Addend);
180 }
181
addRelocations()182 Error addRelocations() override {
183 using namespace support;
184 auto &Obj = getObject();
185
186 LLVM_DEBUG(dbgs() << "Processing relocations:\n");
187
188 for (auto &S : Obj.sections()) {
189
190 JITTargetAddress SectionAddress = S.getAddress();
191
192 // Skip relocations virtual sections.
193 if (S.isVirtual()) {
194 if (S.relocation_begin() != S.relocation_end())
195 return make_error<JITLinkError>("Virtual section contains "
196 "relocations");
197 continue;
198 }
199
200 // Skip relocations for debug symbols.
201 {
202 auto &NSec =
203 getSectionByIndex(Obj.getSectionIndex(S.getRawDataRefImpl()));
204 if (!NSec.GraphSection) {
205 LLVM_DEBUG({
206 dbgs() << " Skipping relocations for MachO section "
207 << NSec.SegName << "/" << NSec.SectName
208 << " which has no associated graph section\n";
209 });
210 continue;
211 }
212 }
213
214 for (auto RelItr = S.relocation_begin(), RelEnd = S.relocation_end();
215 RelItr != RelEnd; ++RelItr) {
216
217 MachO::relocation_info RI = getRelocationInfo(RelItr);
218
219 // Sanity check the relocation kind.
220 auto Kind = getRelocationKind(RI);
221 if (!Kind)
222 return Kind.takeError();
223
224 // Find the address of the value to fix up.
225 JITTargetAddress FixupAddress = SectionAddress + (uint32_t)RI.r_address;
226
227 LLVM_DEBUG({
228 auto &NSec =
229 getSectionByIndex(Obj.getSectionIndex(S.getRawDataRefImpl()));
230 dbgs() << " " << NSec.SectName << " + "
231 << formatv("{0:x8}", RI.r_address) << ":\n";
232 });
233
234 // Find the block that the fixup points to.
235 Block *BlockToFix = nullptr;
236 {
237 auto SymbolToFixOrErr = findSymbolByAddress(FixupAddress);
238 if (!SymbolToFixOrErr)
239 return SymbolToFixOrErr.takeError();
240 BlockToFix = &SymbolToFixOrErr->getBlock();
241 }
242
243 if (FixupAddress + static_cast<JITTargetAddress>(1ULL << RI.r_length) >
244 BlockToFix->getAddress() + BlockToFix->getContent().size())
245 return make_error<JITLinkError>(
246 "Relocation content extends past end of fixup block");
247
248 // Get a pointer to the fixup content.
249 const char *FixupContent = BlockToFix->getContent().data() +
250 (FixupAddress - BlockToFix->getAddress());
251
252 // The target symbol and addend will be populated by the switch below.
253 Symbol *TargetSymbol = nullptr;
254 uint64_t Addend = 0;
255
256 if (*Kind == PairedAddend) {
257 // If this is an Addend relocation then process it and move to the
258 // paired reloc.
259
260 Addend = SignExtend64(RI.r_symbolnum, 24);
261
262 if (RelItr == RelEnd)
263 return make_error<JITLinkError>("Unpaired Addend reloc at " +
264 formatv("{0:x16}", FixupAddress));
265 ++RelItr;
266 RI = getRelocationInfo(RelItr);
267
268 Kind = getRelocationKind(RI);
269 if (!Kind)
270 return Kind.takeError();
271
272 if (*Kind != Branch26 && *Kind != Page21 && *Kind != PageOffset12)
273 return make_error<JITLinkError>(
274 "Invalid relocation pair: Addend + " +
275 StringRef(getMachOARM64RelocationKindName(*Kind)));
276
277 LLVM_DEBUG({
278 dbgs() << " Addend: value = " << formatv("{0:x6}", Addend)
279 << ", pair is " << getMachOARM64RelocationKindName(*Kind)
280 << "\n";
281 });
282
283 // Find the address of the value to fix up.
284 JITTargetAddress PairedFixupAddress =
285 SectionAddress + (uint32_t)RI.r_address;
286 if (PairedFixupAddress != FixupAddress)
287 return make_error<JITLinkError>("Paired relocation points at "
288 "different target");
289 }
290
291 switch (*Kind) {
292 case Branch26: {
293 if (auto TargetSymbolOrErr = findSymbolByIndex(RI.r_symbolnum))
294 TargetSymbol = TargetSymbolOrErr->GraphSymbol;
295 else
296 return TargetSymbolOrErr.takeError();
297 uint32_t Instr = *(const ulittle32_t *)FixupContent;
298 if ((Instr & 0x7fffffff) != 0x14000000)
299 return make_error<JITLinkError>("BRANCH26 target is not a B or BL "
300 "instruction with a zero addend");
301 break;
302 }
303 case Pointer32:
304 if (auto TargetSymbolOrErr = findSymbolByIndex(RI.r_symbolnum))
305 TargetSymbol = TargetSymbolOrErr->GraphSymbol;
306 else
307 return TargetSymbolOrErr.takeError();
308 Addend = *(const ulittle32_t *)FixupContent;
309 break;
310 case Pointer64:
311 if (auto TargetSymbolOrErr = findSymbolByIndex(RI.r_symbolnum))
312 TargetSymbol = TargetSymbolOrErr->GraphSymbol;
313 else
314 return TargetSymbolOrErr.takeError();
315 Addend = *(const ulittle64_t *)FixupContent;
316 break;
317 case Pointer64Anon: {
318 JITTargetAddress TargetAddress = *(const ulittle64_t *)FixupContent;
319 if (auto TargetSymbolOrErr = findSymbolByAddress(TargetAddress))
320 TargetSymbol = &*TargetSymbolOrErr;
321 else
322 return TargetSymbolOrErr.takeError();
323 Addend = TargetAddress - TargetSymbol->getAddress();
324 break;
325 }
326 case Page21:
327 case GOTPage21: {
328 if (auto TargetSymbolOrErr = findSymbolByIndex(RI.r_symbolnum))
329 TargetSymbol = TargetSymbolOrErr->GraphSymbol;
330 else
331 return TargetSymbolOrErr.takeError();
332 uint32_t Instr = *(const ulittle32_t *)FixupContent;
333 if ((Instr & 0xffffffe0) != 0x90000000)
334 return make_error<JITLinkError>("PAGE21/GOTPAGE21 target is not an "
335 "ADRP instruction with a zero "
336 "addend");
337 break;
338 }
339 case PageOffset12: {
340 if (auto TargetSymbolOrErr = findSymbolByIndex(RI.r_symbolnum))
341 TargetSymbol = TargetSymbolOrErr->GraphSymbol;
342 else
343 return TargetSymbolOrErr.takeError();
344 uint32_t Instr = *(const ulittle32_t *)FixupContent;
345 uint32_t EncodedAddend = (Instr & 0x003FFC00) >> 10;
346 if (EncodedAddend != 0)
347 return make_error<JITLinkError>("GOTPAGEOFF12 target has non-zero "
348 "encoded addend");
349 break;
350 }
351 case GOTPageOffset12: {
352 if (auto TargetSymbolOrErr = findSymbolByIndex(RI.r_symbolnum))
353 TargetSymbol = TargetSymbolOrErr->GraphSymbol;
354 else
355 return TargetSymbolOrErr.takeError();
356 uint32_t Instr = *(const ulittle32_t *)FixupContent;
357 if ((Instr & 0xfffffc00) != 0xf9400000)
358 return make_error<JITLinkError>("GOTPAGEOFF12 target is not an LDR "
359 "immediate instruction with a zero "
360 "addend");
361 break;
362 }
363 case PointerToGOT:
364 if (auto TargetSymbolOrErr = findSymbolByIndex(RI.r_symbolnum))
365 TargetSymbol = TargetSymbolOrErr->GraphSymbol;
366 else
367 return TargetSymbolOrErr.takeError();
368 break;
369 case Delta32:
370 case Delta64: {
371 // We use Delta32/Delta64 to represent SUBTRACTOR relocations.
372 // parsePairRelocation handles the paired reloc, and returns the
373 // edge kind to be used (either Delta32/Delta64, or
374 // NegDelta32/NegDelta64, depending on the direction of the
375 // subtraction) along with the addend.
376 auto PairInfo =
377 parsePairRelocation(*BlockToFix, *Kind, RI, FixupAddress,
378 FixupContent, ++RelItr, RelEnd);
379 if (!PairInfo)
380 return PairInfo.takeError();
381 std::tie(*Kind, TargetSymbol, Addend) = *PairInfo;
382 assert(TargetSymbol && "No target symbol from parsePairRelocation?");
383 break;
384 }
385 default:
386 llvm_unreachable("Special relocation kind should not appear in "
387 "mach-o file");
388 }
389
390 LLVM_DEBUG({
391 dbgs() << " ";
392 Edge GE(*Kind, FixupAddress - BlockToFix->getAddress(), *TargetSymbol,
393 Addend);
394 printEdge(dbgs(), *BlockToFix, GE,
395 getMachOARM64RelocationKindName(*Kind));
396 dbgs() << "\n";
397 });
398 BlockToFix->addEdge(*Kind, FixupAddress - BlockToFix->getAddress(),
399 *TargetSymbol, Addend);
400 }
401 }
402 return Error::success();
403 }
404
405 unsigned NumSymbols = 0;
406 };
407
408 class PerGraphGOTAndPLTStubsBuilder_MachO_arm64
409 : public PerGraphGOTAndPLTStubsBuilder<
410 PerGraphGOTAndPLTStubsBuilder_MachO_arm64> {
411 public:
412 using PerGraphGOTAndPLTStubsBuilder<
413 PerGraphGOTAndPLTStubsBuilder_MachO_arm64>::PerGraphGOTAndPLTStubsBuilder;
414
isGOTEdgeToFix(Edge & E) const415 bool isGOTEdgeToFix(Edge &E) const {
416 return (E.getKind() == GOTPage21 || E.getKind() == GOTPageOffset12 ||
417 E.getKind() == PointerToGOT) &&
418 E.getTarget().isExternal();
419 }
420
createGOTEntry(Symbol & Target)421 Symbol &createGOTEntry(Symbol &Target) {
422 auto &GOTEntryBlock = G.createContentBlock(
423 getGOTSection(), getGOTEntryBlockContent(), 0, 8, 0);
424 GOTEntryBlock.addEdge(Pointer64, 0, Target, 0);
425 return G.addAnonymousSymbol(GOTEntryBlock, 0, 8, false, false);
426 }
427
fixGOTEdge(Edge & E,Symbol & GOTEntry)428 void fixGOTEdge(Edge &E, Symbol &GOTEntry) {
429 if (E.getKind() == GOTPage21 || E.getKind() == GOTPageOffset12) {
430 // Update the target, but leave the edge addend as-is.
431 E.setTarget(GOTEntry);
432 } else if (E.getKind() == PointerToGOT) {
433 E.setTarget(GOTEntry);
434 E.setKind(Delta32);
435 } else
436 llvm_unreachable("Not a GOT edge?");
437 }
438
isExternalBranchEdge(Edge & E)439 bool isExternalBranchEdge(Edge &E) {
440 return E.getKind() == Branch26 && !E.getTarget().isDefined();
441 }
442
createPLTStub(Symbol & Target)443 Symbol &createPLTStub(Symbol &Target) {
444 auto &StubContentBlock =
445 G.createContentBlock(getStubsSection(), getStubBlockContent(), 0, 1, 0);
446 // Re-use GOT entries for stub targets.
447 auto &GOTEntrySymbol = getGOTEntry(Target);
448 StubContentBlock.addEdge(LDRLiteral19, 0, GOTEntrySymbol, 0);
449 return G.addAnonymousSymbol(StubContentBlock, 0, 8, true, false);
450 }
451
fixPLTEdge(Edge & E,Symbol & Stub)452 void fixPLTEdge(Edge &E, Symbol &Stub) {
453 assert(E.getKind() == Branch26 && "Not a Branch32 edge?");
454 assert(E.getAddend() == 0 && "Branch32 edge has non-zero addend?");
455 E.setTarget(Stub);
456 }
457
458 private:
getGOTSection()459 Section &getGOTSection() {
460 if (!GOTSection)
461 GOTSection = &G.createSection("$__GOT", sys::Memory::MF_READ);
462 return *GOTSection;
463 }
464
getStubsSection()465 Section &getStubsSection() {
466 if (!StubsSection) {
467 auto StubsProt = static_cast<sys::Memory::ProtectionFlags>(
468 sys::Memory::MF_READ | sys::Memory::MF_EXEC);
469 StubsSection = &G.createSection("$__STUBS", StubsProt);
470 }
471 return *StubsSection;
472 }
473
getGOTEntryBlockContent()474 ArrayRef<char> getGOTEntryBlockContent() {
475 return {reinterpret_cast<const char *>(NullGOTEntryContent),
476 sizeof(NullGOTEntryContent)};
477 }
478
getStubBlockContent()479 ArrayRef<char> getStubBlockContent() {
480 return {reinterpret_cast<const char *>(StubContent), sizeof(StubContent)};
481 }
482
483 static const uint8_t NullGOTEntryContent[8];
484 static const uint8_t StubContent[8];
485 Section *GOTSection = nullptr;
486 Section *StubsSection = nullptr;
487 };
488
489 const uint8_t
490 PerGraphGOTAndPLTStubsBuilder_MachO_arm64::NullGOTEntryContent[8] = {
491 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00};
492 const uint8_t PerGraphGOTAndPLTStubsBuilder_MachO_arm64::StubContent[8] = {
493 0x10, 0x00, 0x00, 0x58, // LDR x16, <literal>
494 0x00, 0x02, 0x1f, 0xd6 // BR x16
495 };
496
497 } // namespace
498
499 namespace llvm {
500 namespace jitlink {
501
502 class MachOJITLinker_arm64 : public JITLinker<MachOJITLinker_arm64> {
503 friend class JITLinker<MachOJITLinker_arm64>;
504
505 public:
MachOJITLinker_arm64(std::unique_ptr<JITLinkContext> Ctx,std::unique_ptr<LinkGraph> G,PassConfiguration PassConfig)506 MachOJITLinker_arm64(std::unique_ptr<JITLinkContext> Ctx,
507 std::unique_ptr<LinkGraph> G,
508 PassConfiguration PassConfig)
509 : JITLinker(std::move(Ctx), std::move(G), std::move(PassConfig)) {}
510
511 private:
512
getPageOffset12Shift(uint32_t Instr)513 static unsigned getPageOffset12Shift(uint32_t Instr) {
514 constexpr uint32_t LoadStoreImm12Mask = 0x3b000000;
515 constexpr uint32_t Vec128Mask = 0x04800000;
516
517 if ((Instr & LoadStoreImm12Mask) == 0x39000000) {
518 uint32_t ImplicitShift = Instr >> 30;
519 if (ImplicitShift == 0)
520 if ((Instr & Vec128Mask) == Vec128Mask)
521 ImplicitShift = 4;
522
523 return ImplicitShift;
524 }
525
526 return 0;
527 }
528
applyFixup(LinkGraph & G,Block & B,const Edge & E,char * BlockWorkingMem) const529 Error applyFixup(LinkGraph &G, Block &B, const Edge &E,
530 char *BlockWorkingMem) const {
531 using namespace support;
532
533 char *FixupPtr = BlockWorkingMem + E.getOffset();
534 JITTargetAddress FixupAddress = B.getAddress() + E.getOffset();
535
536 switch (E.getKind()) {
537 case Branch26: {
538 assert((FixupAddress & 0x3) == 0 && "Branch-inst is not 32-bit aligned");
539
540 int64_t Value = E.getTarget().getAddress() - FixupAddress + E.getAddend();
541
542 if (static_cast<uint64_t>(Value) & 0x3)
543 return make_error<JITLinkError>("Branch26 target is not 32-bit "
544 "aligned");
545
546 if (Value < -(1 << 27) || Value > ((1 << 27) - 1))
547 return makeTargetOutOfRangeError(G, B, E);
548
549 uint32_t RawInstr = *(little32_t *)FixupPtr;
550 assert((RawInstr & 0x7fffffff) == 0x14000000 &&
551 "RawInstr isn't a B or BR immediate instruction");
552 uint32_t Imm = (static_cast<uint32_t>(Value) & ((1 << 28) - 1)) >> 2;
553 uint32_t FixedInstr = RawInstr | Imm;
554 *(little32_t *)FixupPtr = FixedInstr;
555 break;
556 }
557 case Pointer32: {
558 uint64_t Value = E.getTarget().getAddress() + E.getAddend();
559 if (Value > std::numeric_limits<uint32_t>::max())
560 return makeTargetOutOfRangeError(G, B, E);
561 *(ulittle32_t *)FixupPtr = Value;
562 break;
563 }
564 case Pointer64:
565 case Pointer64Anon: {
566 uint64_t Value = E.getTarget().getAddress() + E.getAddend();
567 *(ulittle64_t *)FixupPtr = Value;
568 break;
569 }
570 case Page21:
571 case GOTPage21: {
572 assert((E.getKind() != GOTPage21 || E.getAddend() == 0) &&
573 "GOTPAGE21 with non-zero addend");
574 uint64_t TargetPage =
575 (E.getTarget().getAddress() + E.getAddend()) &
576 ~static_cast<uint64_t>(4096 - 1);
577 uint64_t PCPage = FixupAddress & ~static_cast<uint64_t>(4096 - 1);
578
579 int64_t PageDelta = TargetPage - PCPage;
580 if (PageDelta < -(1 << 30) || PageDelta > ((1 << 30) - 1))
581 return makeTargetOutOfRangeError(G, B, E);
582
583 uint32_t RawInstr = *(ulittle32_t *)FixupPtr;
584 assert((RawInstr & 0xffffffe0) == 0x90000000 &&
585 "RawInstr isn't an ADRP instruction");
586 uint32_t ImmLo = (static_cast<uint64_t>(PageDelta) >> 12) & 0x3;
587 uint32_t ImmHi = (static_cast<uint64_t>(PageDelta) >> 14) & 0x7ffff;
588 uint32_t FixedInstr = RawInstr | (ImmLo << 29) | (ImmHi << 5);
589 *(ulittle32_t *)FixupPtr = FixedInstr;
590 break;
591 }
592 case PageOffset12: {
593 uint64_t TargetOffset =
594 (E.getTarget().getAddress() + E.getAddend()) & 0xfff;
595
596 uint32_t RawInstr = *(ulittle32_t *)FixupPtr;
597 unsigned ImmShift = getPageOffset12Shift(RawInstr);
598
599 if (TargetOffset & ((1 << ImmShift) - 1))
600 return make_error<JITLinkError>("PAGEOFF12 target is not aligned");
601
602 uint32_t EncodedImm = (TargetOffset >> ImmShift) << 10;
603 uint32_t FixedInstr = RawInstr | EncodedImm;
604 *(ulittle32_t *)FixupPtr = FixedInstr;
605 break;
606 }
607 case GOTPageOffset12: {
608 assert(E.getAddend() == 0 && "GOTPAGEOF12 with non-zero addend");
609
610 uint32_t RawInstr = *(ulittle32_t *)FixupPtr;
611 assert((RawInstr & 0xfffffc00) == 0xf9400000 &&
612 "RawInstr isn't a 64-bit LDR immediate");
613
614 uint32_t TargetOffset = E.getTarget().getAddress() & 0xfff;
615 assert((TargetOffset & 0x7) == 0 && "GOT entry is not 8-byte aligned");
616 uint32_t EncodedImm = (TargetOffset >> 3) << 10;
617 uint32_t FixedInstr = RawInstr | EncodedImm;
618 *(ulittle32_t *)FixupPtr = FixedInstr;
619 break;
620 }
621 case LDRLiteral19: {
622 assert((FixupAddress & 0x3) == 0 && "LDR is not 32-bit aligned");
623 assert(E.getAddend() == 0 && "LDRLiteral19 with non-zero addend");
624 uint32_t RawInstr = *(ulittle32_t *)FixupPtr;
625 assert(RawInstr == 0x58000010 && "RawInstr isn't a 64-bit LDR literal");
626 int64_t Delta = E.getTarget().getAddress() - FixupAddress;
627 if (Delta & 0x3)
628 return make_error<JITLinkError>("LDR literal target is not 32-bit "
629 "aligned");
630 if (Delta < -(1 << 20) || Delta > ((1 << 20) - 1))
631 return makeTargetOutOfRangeError(G, B, E);
632
633 uint32_t EncodedImm = (static_cast<uint32_t>(Delta) >> 2) << 5;
634 uint32_t FixedInstr = RawInstr | EncodedImm;
635 *(ulittle32_t *)FixupPtr = FixedInstr;
636 break;
637 }
638 case Delta32:
639 case Delta64:
640 case NegDelta32:
641 case NegDelta64: {
642 int64_t Value;
643 if (E.getKind() == Delta32 || E.getKind() == Delta64)
644 Value = E.getTarget().getAddress() - FixupAddress + E.getAddend();
645 else
646 Value = FixupAddress - E.getTarget().getAddress() + E.getAddend();
647
648 if (E.getKind() == Delta32 || E.getKind() == NegDelta32) {
649 if (Value < std::numeric_limits<int32_t>::min() ||
650 Value > std::numeric_limits<int32_t>::max())
651 return makeTargetOutOfRangeError(G, B, E);
652 *(little32_t *)FixupPtr = Value;
653 } else
654 *(little64_t *)FixupPtr = Value;
655 break;
656 }
657 default:
658 llvm_unreachable("Unrecognized edge kind");
659 }
660
661 return Error::success();
662 }
663
664 uint64_t NullValue = 0;
665 };
666
667 Expected<std::unique_ptr<LinkGraph>>
createLinkGraphFromMachOObject_arm64(MemoryBufferRef ObjectBuffer)668 createLinkGraphFromMachOObject_arm64(MemoryBufferRef ObjectBuffer) {
669 auto MachOObj = object::ObjectFile::createMachOObjectFile(ObjectBuffer);
670 if (!MachOObj)
671 return MachOObj.takeError();
672 return MachOLinkGraphBuilder_arm64(**MachOObj).buildGraph();
673 }
674
link_MachO_arm64(std::unique_ptr<LinkGraph> G,std::unique_ptr<JITLinkContext> Ctx)675 void link_MachO_arm64(std::unique_ptr<LinkGraph> G,
676 std::unique_ptr<JITLinkContext> Ctx) {
677
678 PassConfiguration Config;
679
680 if (Ctx->shouldAddDefaultTargetPasses(G->getTargetTriple())) {
681 // Add a mark-live pass.
682 if (auto MarkLive = Ctx->getMarkLivePass(G->getTargetTriple()))
683 Config.PrePrunePasses.push_back(std::move(MarkLive));
684 else
685 Config.PrePrunePasses.push_back(markAllSymbolsLive);
686
687 // Add an in-place GOT/Stubs pass.
688 Config.PostPrunePasses.push_back(
689 PerGraphGOTAndPLTStubsBuilder_MachO_arm64::asPass);
690 }
691
692 if (auto Err = Ctx->modifyPassConfig(*G, Config))
693 return Ctx->notifyFailed(std::move(Err));
694
695 // Construct a JITLinker and run the link function.
696 MachOJITLinker_arm64::link(std::move(Ctx), std::move(G), std::move(Config));
697 }
698
getMachOARM64RelocationKindName(Edge::Kind R)699 const char *getMachOARM64RelocationKindName(Edge::Kind R) {
700 switch (R) {
701 case Branch26:
702 return "Branch26";
703 case Pointer64:
704 return "Pointer64";
705 case Pointer64Anon:
706 return "Pointer64Anon";
707 case Page21:
708 return "Page21";
709 case PageOffset12:
710 return "PageOffset12";
711 case GOTPage21:
712 return "GOTPage21";
713 case GOTPageOffset12:
714 return "GOTPageOffset12";
715 case PointerToGOT:
716 return "PointerToGOT";
717 case PairedAddend:
718 return "PairedAddend";
719 case LDRLiteral19:
720 return "LDRLiteral19";
721 case Delta32:
722 return "Delta32";
723 case Delta64:
724 return "Delta64";
725 case NegDelta32:
726 return "NegDelta32";
727 case NegDelta64:
728 return "NegDelta64";
729 default:
730 return getGenericEdgeKindName(static_cast<Edge::Kind>(R));
731 }
732 }
733
734 } // end namespace jitlink
735 } // end namespace llvm
736