1 //===-- RuntimeDyldELF.cpp - Run-time dynamic linker for MC-JIT -*- C++ -*-===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // Implementation of ELF support for the MC-JIT runtime dynamic linker.
12 //===----------------------------------------------------------------------===//
14 #include "RuntimeDyldELF.h"
15 #include "RuntimeDyldCheckerImpl.h"
16 #include "llvm/ADT/IntervalMap.h"
17 #include "llvm/ADT/STLExtras.h"
18 #include "llvm/ADT/StringRef.h"
19 #include "llvm/ADT/Triple.h"
20 #include "llvm/MC/MCStreamer.h"
21 #include "llvm/Object/ELFObjectFile.h"
22 #include "llvm/Object/ObjectFile.h"
23 #include "llvm/Support/ELF.h"
24 #include "llvm/Support/Endian.h"
25 #include "llvm/Support/MemoryBuffer.h"
26 #include "llvm/Support/TargetRegistry.h"
29 using namespace llvm::object;
31 #define DEBUG_TYPE "dyld"
33 static inline std::error_code check(std::error_code Err) {
35 report_fatal_error(Err.message());
42 template <class ELFT> class DyldELFObject : public ELFObjectFile<ELFT> {
43 LLVM_ELF_IMPORT_TYPES_ELFT(ELFT)
45 typedef Elf_Shdr_Impl<ELFT> Elf_Shdr;
46 typedef Elf_Sym_Impl<ELFT> Elf_Sym;
47 typedef Elf_Rel_Impl<ELFT, false> Elf_Rel;
48 typedef Elf_Rel_Impl<ELFT, true> Elf_Rela;
50 typedef Elf_Ehdr_Impl<ELFT> Elf_Ehdr;
52 typedef typename ELFDataTypeTypedefHelper<ELFT>::value_type addr_type;
55 DyldELFObject(MemoryBufferRef Wrapper, std::error_code &ec);
57 void updateSectionAddress(const SectionRef &Sec, uint64_t Addr);
59 void updateSymbolAddress(const SymbolRef &SymRef, uint64_t Addr);
61 // Methods for type inquiry through isa, cast and dyn_cast
62 static inline bool classof(const Binary *v) {
63 return (isa<ELFObjectFile<ELFT>>(v) &&
64 classof(cast<ELFObjectFile<ELFT>>(v)));
66 static inline bool classof(const ELFObjectFile<ELFT> *v) {
67 return v->isDyldType();
74 // The MemoryBuffer passed into this constructor is just a wrapper around the
75 // actual memory. Ultimately, the Binary parent class will take ownership of
76 // this MemoryBuffer object but not the underlying memory.
78 DyldELFObject<ELFT>::DyldELFObject(MemoryBufferRef Wrapper, std::error_code &EC)
79 : ELFObjectFile<ELFT>(Wrapper, EC) {
80 this->isDyldELFObject = true;
84 void DyldELFObject<ELFT>::updateSectionAddress(const SectionRef &Sec,
86 DataRefImpl ShdrRef = Sec.getRawDataRefImpl();
88 const_cast<Elf_Shdr *>(reinterpret_cast<const Elf_Shdr *>(ShdrRef.p));
90 // This assumes the address passed in matches the target address bitness
91 // The template-based type cast handles everything else.
92 shdr->sh_addr = static_cast<addr_type>(Addr);
96 void DyldELFObject<ELFT>::updateSymbolAddress(const SymbolRef &SymRef,
99 Elf_Sym *sym = const_cast<Elf_Sym *>(
100 ELFObjectFile<ELFT>::getSymbol(SymRef.getRawDataRefImpl()));
102 // This assumes the address passed in matches the target address bitness
103 // The template-based type cast handles everything else.
104 sym->st_value = static_cast<addr_type>(Addr);
107 class LoadedELFObjectInfo : public RuntimeDyld::LoadedObjectInfo {
109 LoadedELFObjectInfo(RuntimeDyldImpl &RTDyld, unsigned BeginIdx,
111 : RuntimeDyld::LoadedObjectInfo(RTDyld, BeginIdx, EndIdx) {}
113 OwningBinary<ObjectFile>
114 getObjectForDebug(const ObjectFile &Obj) const override;
116 RuntimeDyld::LoadedObjectInfo *clone() const { return new LoadedELFObjectInfo(*this); }
119 template <typename ELFT>
120 std::unique_ptr<DyldELFObject<ELFT>>
121 createRTDyldELFObject(MemoryBufferRef Buffer,
122 const LoadedELFObjectInfo &L,
123 std::error_code &ec) {
124 typedef typename ELFFile<ELFT>::Elf_Shdr Elf_Shdr;
125 typedef typename ELFDataTypeTypedefHelper<ELFT>::value_type addr_type;
127 std::unique_ptr<DyldELFObject<ELFT>> Obj =
128 llvm::make_unique<DyldELFObject<ELFT>>(Buffer, ec);
130 // Iterate over all sections in the object.
131 for (const auto &Sec : Obj->sections()) {
132 StringRef SectionName;
133 Sec.getName(SectionName);
134 if (SectionName != "") {
135 DataRefImpl ShdrRef = Sec.getRawDataRefImpl();
136 Elf_Shdr *shdr = const_cast<Elf_Shdr *>(
137 reinterpret_cast<const Elf_Shdr *>(ShdrRef.p));
139 if (uint64_t SecLoadAddr = L.getSectionLoadAddress(SectionName)) {
140 // This assumes that the address passed in matches the target address
141 // bitness. The template-based type cast handles everything else.
142 shdr->sh_addr = static_cast<addr_type>(SecLoadAddr);
150 OwningBinary<ObjectFile> createELFDebugObject(const ObjectFile &Obj,
151 const LoadedELFObjectInfo &L) {
152 assert(Obj.isELF() && "Not an ELF object file.");
154 std::unique_ptr<MemoryBuffer> Buffer =
155 MemoryBuffer::getMemBufferCopy(Obj.getData(), Obj.getFileName());
159 std::unique_ptr<ObjectFile> DebugObj;
160 if (Obj.getBytesInAddress() == 4 && Obj.isLittleEndian()) {
161 typedef ELFType<support::little, 2, false> ELF32LE;
162 DebugObj = createRTDyldELFObject<ELF32LE>(Buffer->getMemBufferRef(), L, ec);
163 } else if (Obj.getBytesInAddress() == 4 && !Obj.isLittleEndian()) {
164 typedef ELFType<support::big, 2, false> ELF32BE;
165 DebugObj = createRTDyldELFObject<ELF32BE>(Buffer->getMemBufferRef(), L, ec);
166 } else if (Obj.getBytesInAddress() == 8 && !Obj.isLittleEndian()) {
167 typedef ELFType<support::big, 2, true> ELF64BE;
168 DebugObj = createRTDyldELFObject<ELF64BE>(Buffer->getMemBufferRef(), L, ec);
169 } else if (Obj.getBytesInAddress() == 8 && Obj.isLittleEndian()) {
170 typedef ELFType<support::little, 2, true> ELF64LE;
171 DebugObj = createRTDyldELFObject<ELF64LE>(Buffer->getMemBufferRef(), L, ec);
173 llvm_unreachable("Unexpected ELF format");
175 assert(!ec && "Could not construct copy ELF object file");
177 return OwningBinary<ObjectFile>(std::move(DebugObj), std::move(Buffer));
180 OwningBinary<ObjectFile>
181 LoadedELFObjectInfo::getObjectForDebug(const ObjectFile &Obj) const {
182 return createELFDebugObject(Obj, *this);
189 RuntimeDyldELF::RuntimeDyldELF(RuntimeDyld::MemoryManager &MemMgr,
190 RuntimeDyld::SymbolResolver &Resolver)
191 : RuntimeDyldImpl(MemMgr, Resolver), GOTSectionID(0), CurrentGOTIndex(0) {}
192 RuntimeDyldELF::~RuntimeDyldELF() {}
194 void RuntimeDyldELF::registerEHFrames() {
195 for (int i = 0, e = UnregisteredEHFrameSections.size(); i != e; ++i) {
196 SID EHFrameSID = UnregisteredEHFrameSections[i];
197 uint8_t *EHFrameAddr = Sections[EHFrameSID].Address;
198 uint64_t EHFrameLoadAddr = Sections[EHFrameSID].LoadAddress;
199 size_t EHFrameSize = Sections[EHFrameSID].Size;
200 MemMgr.registerEHFrames(EHFrameAddr, EHFrameLoadAddr, EHFrameSize);
201 RegisteredEHFrameSections.push_back(EHFrameSID);
203 UnregisteredEHFrameSections.clear();
206 void RuntimeDyldELF::deregisterEHFrames() {
207 for (int i = 0, e = RegisteredEHFrameSections.size(); i != e; ++i) {
208 SID EHFrameSID = RegisteredEHFrameSections[i];
209 uint8_t *EHFrameAddr = Sections[EHFrameSID].Address;
210 uint64_t EHFrameLoadAddr = Sections[EHFrameSID].LoadAddress;
211 size_t EHFrameSize = Sections[EHFrameSID].Size;
212 MemMgr.deregisterEHFrames(EHFrameAddr, EHFrameLoadAddr, EHFrameSize);
214 RegisteredEHFrameSections.clear();
217 std::unique_ptr<RuntimeDyld::LoadedObjectInfo>
218 RuntimeDyldELF::loadObject(const object::ObjectFile &O) {
219 unsigned SectionStartIdx, SectionEndIdx;
220 std::tie(SectionStartIdx, SectionEndIdx) = loadObjectImpl(O);
221 return llvm::make_unique<LoadedELFObjectInfo>(*this, SectionStartIdx,
225 void RuntimeDyldELF::resolveX86_64Relocation(const SectionEntry &Section,
226 uint64_t Offset, uint64_t Value,
227 uint32_t Type, int64_t Addend,
228 uint64_t SymOffset) {
231 llvm_unreachable("Relocation type not implemented yet!");
233 case ELF::R_X86_64_64: {
234 support::ulittle64_t::ref(Section.Address + Offset) = Value + Addend;
235 DEBUG(dbgs() << "Writing " << format("%p", (Value + Addend)) << " at "
236 << format("%p\n", Section.Address + Offset));
239 case ELF::R_X86_64_32:
240 case ELF::R_X86_64_32S: {
242 assert((Type == ELF::R_X86_64_32 && (Value <= UINT32_MAX)) ||
243 (Type == ELF::R_X86_64_32S &&
244 ((int64_t)Value <= INT32_MAX && (int64_t)Value >= INT32_MIN)));
245 uint32_t TruncatedAddr = (Value & 0xFFFFFFFF);
246 support::ulittle32_t::ref(Section.Address + Offset) = TruncatedAddr;
247 DEBUG(dbgs() << "Writing " << format("%p", TruncatedAddr) << " at "
248 << format("%p\n", Section.Address + Offset));
251 case ELF::R_X86_64_PC32: {
252 uint64_t FinalAddress = Section.LoadAddress + Offset;
253 int64_t RealOffset = Value + Addend - FinalAddress;
254 assert(isInt<32>(RealOffset));
255 int32_t TruncOffset = (RealOffset & 0xFFFFFFFF);
256 support::ulittle32_t::ref(Section.Address + Offset) = TruncOffset;
259 case ELF::R_X86_64_PC64: {
260 uint64_t FinalAddress = Section.LoadAddress + Offset;
261 int64_t RealOffset = Value + Addend - FinalAddress;
262 support::ulittle64_t::ref(Section.Address + Offset) = RealOffset;
268 void RuntimeDyldELF::resolveX86Relocation(const SectionEntry &Section,
269 uint64_t Offset, uint32_t Value,
270 uint32_t Type, int32_t Addend) {
272 case ELF::R_386_32: {
273 support::ulittle32_t::ref(Section.Address + Offset) = Value + Addend;
276 case ELF::R_386_PC32: {
277 uint32_t FinalAddress = ((Section.LoadAddress + Offset) & 0xFFFFFFFF);
278 uint32_t RealOffset = Value + Addend - FinalAddress;
279 support::ulittle32_t::ref(Section.Address + Offset) = RealOffset;
283 // There are other relocation types, but it appears these are the
284 // only ones currently used by the LLVM ELF object writer
285 llvm_unreachable("Relocation type not implemented yet!");
290 void RuntimeDyldELF::resolveAArch64Relocation(const SectionEntry &Section,
291 uint64_t Offset, uint64_t Value,
292 uint32_t Type, int64_t Addend) {
293 uint32_t *TargetPtr = reinterpret_cast<uint32_t *>(Section.Address + Offset);
294 uint64_t FinalAddress = Section.LoadAddress + Offset;
296 DEBUG(dbgs() << "resolveAArch64Relocation, LocalAddress: 0x"
297 << format("%llx", Section.Address + Offset)
298 << " FinalAddress: 0x" << format("%llx", FinalAddress)
299 << " Value: 0x" << format("%llx", Value) << " Type: 0x"
300 << format("%x", Type) << " Addend: 0x" << format("%llx", Addend)
305 llvm_unreachable("Relocation type not implemented yet!");
307 case ELF::R_AARCH64_ABS64: {
308 uint64_t *TargetPtr =
309 reinterpret_cast<uint64_t *>(Section.Address + Offset);
310 *TargetPtr = Value + Addend;
313 case ELF::R_AARCH64_PREL32: {
314 uint64_t Result = Value + Addend - FinalAddress;
315 assert(static_cast<int64_t>(Result) >= INT32_MIN &&
316 static_cast<int64_t>(Result) <= UINT32_MAX);
317 *TargetPtr = static_cast<uint32_t>(Result & 0xffffffffU);
320 case ELF::R_AARCH64_CALL26: // fallthrough
321 case ELF::R_AARCH64_JUMP26: {
322 // Operation: S+A-P. Set Call or B immediate value to bits fff_fffc of the
324 uint64_t BranchImm = Value + Addend - FinalAddress;
326 // "Check that -2^27 <= result < 2^27".
327 assert(isInt<28>(BranchImm));
329 // AArch64 code is emitted with .rela relocations. The data already in any
330 // bits affected by the relocation on entry is garbage.
331 *TargetPtr &= 0xfc000000U;
332 // Immediate goes in bits 25:0 of B and BL.
333 *TargetPtr |= static_cast<uint32_t>(BranchImm & 0xffffffcU) >> 2;
336 case ELF::R_AARCH64_MOVW_UABS_G3: {
337 uint64_t Result = Value + Addend;
339 // AArch64 code is emitted with .rela relocations. The data already in any
340 // bits affected by the relocation on entry is garbage.
341 *TargetPtr &= 0xffe0001fU;
342 // Immediate goes in bits 20:5 of MOVZ/MOVK instruction
343 *TargetPtr |= Result >> (48 - 5);
344 // Shift must be "lsl #48", in bits 22:21
345 assert((*TargetPtr >> 21 & 0x3) == 3 && "invalid shift for relocation");
348 case ELF::R_AARCH64_MOVW_UABS_G2_NC: {
349 uint64_t Result = Value + Addend;
351 // AArch64 code is emitted with .rela relocations. The data already in any
352 // bits affected by the relocation on entry is garbage.
353 *TargetPtr &= 0xffe0001fU;
354 // Immediate goes in bits 20:5 of MOVZ/MOVK instruction
355 *TargetPtr |= ((Result & 0xffff00000000ULL) >> (32 - 5));
356 // Shift must be "lsl #32", in bits 22:21
357 assert((*TargetPtr >> 21 & 0x3) == 2 && "invalid shift for relocation");
360 case ELF::R_AARCH64_MOVW_UABS_G1_NC: {
361 uint64_t Result = Value + Addend;
363 // AArch64 code is emitted with .rela relocations. The data already in any
364 // bits affected by the relocation on entry is garbage.
365 *TargetPtr &= 0xffe0001fU;
366 // Immediate goes in bits 20:5 of MOVZ/MOVK instruction
367 *TargetPtr |= ((Result & 0xffff0000U) >> (16 - 5));
368 // Shift must be "lsl #16", in bits 22:2
369 assert((*TargetPtr >> 21 & 0x3) == 1 && "invalid shift for relocation");
372 case ELF::R_AARCH64_MOVW_UABS_G0_NC: {
373 uint64_t Result = Value + Addend;
375 // AArch64 code is emitted with .rela relocations. The data already in any
376 // bits affected by the relocation on entry is garbage.
377 *TargetPtr &= 0xffe0001fU;
378 // Immediate goes in bits 20:5 of MOVZ/MOVK instruction
379 *TargetPtr |= ((Result & 0xffffU) << 5);
380 // Shift must be "lsl #0", in bits 22:21.
381 assert((*TargetPtr >> 21 & 0x3) == 0 && "invalid shift for relocation");
384 case ELF::R_AARCH64_ADR_PREL_PG_HI21: {
385 // Operation: Page(S+A) - Page(P)
387 ((Value + Addend) & ~0xfffULL) - (FinalAddress & ~0xfffULL);
389 // Check that -2^32 <= X < 2^32
390 assert(isInt<33>(Result) && "overflow check failed for relocation");
392 // AArch64 code is emitted with .rela relocations. The data already in any
393 // bits affected by the relocation on entry is garbage.
394 *TargetPtr &= 0x9f00001fU;
395 // Immediate goes in bits 30:29 + 5:23 of ADRP instruction, taken
396 // from bits 32:12 of X.
397 *TargetPtr |= ((Result & 0x3000U) << (29 - 12));
398 *TargetPtr |= ((Result & 0x1ffffc000ULL) >> (14 - 5));
401 case ELF::R_AARCH64_LDST32_ABS_LO12_NC: {
403 uint64_t Result = Value + Addend;
405 // AArch64 code is emitted with .rela relocations. The data already in any
406 // bits affected by the relocation on entry is garbage.
407 *TargetPtr &= 0xffc003ffU;
408 // Immediate goes in bits 21:10 of LD/ST instruction, taken
409 // from bits 11:2 of X
410 *TargetPtr |= ((Result & 0xffc) << (10 - 2));
413 case ELF::R_AARCH64_LDST64_ABS_LO12_NC: {
415 uint64_t Result = Value + Addend;
417 // AArch64 code is emitted with .rela relocations. The data already in any
418 // bits affected by the relocation on entry is garbage.
419 *TargetPtr &= 0xffc003ffU;
420 // Immediate goes in bits 21:10 of LD/ST instruction, taken
421 // from bits 11:3 of X
422 *TargetPtr |= ((Result & 0xff8) << (10 - 3));
428 void RuntimeDyldELF::resolveARMRelocation(const SectionEntry &Section,
429 uint64_t Offset, uint32_t Value,
430 uint32_t Type, int32_t Addend) {
431 // TODO: Add Thumb relocations.
432 uint32_t *TargetPtr = (uint32_t *)(Section.Address + Offset);
433 uint32_t FinalAddress = ((Section.LoadAddress + Offset) & 0xFFFFFFFF);
436 DEBUG(dbgs() << "resolveARMRelocation, LocalAddress: "
437 << Section.Address + Offset
438 << " FinalAddress: " << format("%p", FinalAddress) << " Value: "
439 << format("%x", Value) << " Type: " << format("%x", Type)
440 << " Addend: " << format("%x", Addend) << "\n");
444 llvm_unreachable("Not implemented relocation type!");
446 case ELF::R_ARM_NONE:
448 case ELF::R_ARM_PREL31:
449 case ELF::R_ARM_TARGET1:
450 case ELF::R_ARM_ABS32:
453 // Write first 16 bit of 32 bit value to the mov instruction.
454 // Last 4 bit should be shifted.
455 case ELF::R_ARM_MOVW_ABS_NC:
456 case ELF::R_ARM_MOVT_ABS:
457 if (Type == ELF::R_ARM_MOVW_ABS_NC)
458 Value = Value & 0xFFFF;
459 else if (Type == ELF::R_ARM_MOVT_ABS)
460 Value = (Value >> 16) & 0xFFFF;
461 *TargetPtr &= ~0x000F0FFF;
462 *TargetPtr |= Value & 0xFFF;
463 *TargetPtr |= ((Value >> 12) & 0xF) << 16;
465 // Write 24 bit relative value to the branch instruction.
466 case ELF::R_ARM_PC24: // Fall through.
467 case ELF::R_ARM_CALL: // Fall through.
468 case ELF::R_ARM_JUMP24:
469 int32_t RelValue = static_cast<int32_t>(Value - FinalAddress - 8);
470 RelValue = (RelValue & 0x03FFFFFC) >> 2;
471 assert((*TargetPtr & 0xFFFFFF) == 0xFFFFFE);
472 *TargetPtr &= 0xFF000000;
473 *TargetPtr |= RelValue;
478 void RuntimeDyldELF::resolveMIPSRelocation(const SectionEntry &Section,
479 uint64_t Offset, uint32_t Value,
480 uint32_t Type, int32_t Addend) {
481 uint32_t *TargetPtr = (uint32_t *)(Section.Address + Offset);
484 DEBUG(dbgs() << "resolveMipselocation, LocalAddress: "
485 << Section.Address + Offset << " FinalAddress: "
486 << format("%p", Section.LoadAddress + Offset) << " Value: "
487 << format("%x", Value) << " Type: " << format("%x", Type)
488 << " Addend: " << format("%x", Addend) << "\n");
492 llvm_unreachable("Not implemented relocation type!");
498 *TargetPtr = ((*TargetPtr) & 0xfc000000) | ((Value & 0x0fffffff) >> 2);
500 case ELF::R_MIPS_HI16:
501 // Get the higher 16-bits. Also add 1 if bit 15 is 1.
503 ((*TargetPtr) & 0xffff0000) | (((Value + 0x8000) >> 16) & 0xffff);
505 case ELF::R_MIPS_LO16:
506 *TargetPtr = ((*TargetPtr) & 0xffff0000) | (Value & 0xffff);
511 // Return the .TOC. section and offset.
512 void RuntimeDyldELF::findPPC64TOCSection(const ObjectFile &Obj,
513 ObjSectionToIDMap &LocalSections,
514 RelocationValueRef &Rel) {
515 // Set a default SectionID in case we do not find a TOC section below.
516 // This may happen for references to TOC base base (sym@toc, .odp
517 // relocation) without a .toc directive. In this case just use the
518 // first section (which is usually the .odp) since the code won't
519 // reference the .toc base directly.
520 Rel.SymbolName = NULL;
523 // The TOC consists of sections .got, .toc, .tocbss, .plt in that
524 // order. The TOC starts where the first of these sections starts.
525 for (section_iterator si = Obj.section_begin(), se = Obj.section_end();
528 StringRef SectionName;
529 check(si->getName(SectionName));
531 if (SectionName == ".got"
532 || SectionName == ".toc"
533 || SectionName == ".tocbss"
534 || SectionName == ".plt") {
535 Rel.SectionID = findOrEmitSection(Obj, *si, false, LocalSections);
540 // Per the ppc64-elf-linux ABI, The TOC base is TOC value plus 0x8000
541 // thus permitting a full 64 Kbytes segment.
545 // Returns the sections and offset associated with the ODP entry referenced
547 void RuntimeDyldELF::findOPDEntrySection(const ObjectFile &Obj,
548 ObjSectionToIDMap &LocalSections,
549 RelocationValueRef &Rel) {
550 // Get the ELF symbol value (st_value) to compare with Relocation offset in
552 for (section_iterator si = Obj.section_begin(), se = Obj.section_end();
554 section_iterator RelSecI = si->getRelocatedSection();
555 if (RelSecI == Obj.section_end())
558 StringRef RelSectionName;
559 check(RelSecI->getName(RelSectionName));
560 if (RelSectionName != ".opd")
563 for (relocation_iterator i = si->relocation_begin(),
564 e = si->relocation_end();
566 // The R_PPC64_ADDR64 relocation indicates the first field
569 check(i->getType(TypeFunc));
570 if (TypeFunc != ELF::R_PPC64_ADDR64) {
575 uint64_t TargetSymbolOffset;
576 symbol_iterator TargetSymbol = i->getSymbol();
577 check(i->getOffset(TargetSymbolOffset));
579 check(getELFRelocationAddend(*i, Addend));
585 // Just check if following relocation is a R_PPC64_TOC
587 check(i->getType(TypeTOC));
588 if (TypeTOC != ELF::R_PPC64_TOC)
591 // Finally compares the Symbol value and the target symbol offset
592 // to check if this .opd entry refers to the symbol the relocation
594 if (Rel.Addend != (int64_t)TargetSymbolOffset)
597 section_iterator tsi(Obj.section_end());
598 check(TargetSymbol->getSection(tsi));
599 bool IsCode = tsi->isText();
600 Rel.SectionID = findOrEmitSection(Obj, (*tsi), IsCode, LocalSections);
601 Rel.Addend = (intptr_t)Addend;
605 llvm_unreachable("Attempting to get address of ODP entry!");
608 // Relocation masks following the #lo(value), #hi(value), #ha(value),
609 // #higher(value), #highera(value), #highest(value), and #highesta(value)
610 // macros defined in section 4.5.1. Relocation Types of the PPC-elf64abi
613 static inline uint16_t applyPPClo(uint64_t value) { return value & 0xffff; }
615 static inline uint16_t applyPPChi(uint64_t value) {
616 return (value >> 16) & 0xffff;
619 static inline uint16_t applyPPCha (uint64_t value) {
620 return ((value + 0x8000) >> 16) & 0xffff;
623 static inline uint16_t applyPPChigher(uint64_t value) {
624 return (value >> 32) & 0xffff;
627 static inline uint16_t applyPPChighera (uint64_t value) {
628 return ((value + 0x8000) >> 32) & 0xffff;
631 static inline uint16_t applyPPChighest(uint64_t value) {
632 return (value >> 48) & 0xffff;
635 static inline uint16_t applyPPChighesta (uint64_t value) {
636 return ((value + 0x8000) >> 48) & 0xffff;
639 void RuntimeDyldELF::resolvePPC64Relocation(const SectionEntry &Section,
640 uint64_t Offset, uint64_t Value,
641 uint32_t Type, int64_t Addend) {
642 uint8_t *LocalAddress = Section.Address + Offset;
645 llvm_unreachable("Relocation type not implemented yet!");
647 case ELF::R_PPC64_ADDR16:
648 writeInt16BE(LocalAddress, applyPPClo(Value + Addend));
650 case ELF::R_PPC64_ADDR16_DS:
651 writeInt16BE(LocalAddress, applyPPClo(Value + Addend) & ~3);
653 case ELF::R_PPC64_ADDR16_LO:
654 writeInt16BE(LocalAddress, applyPPClo(Value + Addend));
656 case ELF::R_PPC64_ADDR16_LO_DS:
657 writeInt16BE(LocalAddress, applyPPClo(Value + Addend) & ~3);
659 case ELF::R_PPC64_ADDR16_HI:
660 writeInt16BE(LocalAddress, applyPPChi(Value + Addend));
662 case ELF::R_PPC64_ADDR16_HA:
663 writeInt16BE(LocalAddress, applyPPCha(Value + Addend));
665 case ELF::R_PPC64_ADDR16_HIGHER:
666 writeInt16BE(LocalAddress, applyPPChigher(Value + Addend));
668 case ELF::R_PPC64_ADDR16_HIGHERA:
669 writeInt16BE(LocalAddress, applyPPChighera(Value + Addend));
671 case ELF::R_PPC64_ADDR16_HIGHEST:
672 writeInt16BE(LocalAddress, applyPPChighest(Value + Addend));
674 case ELF::R_PPC64_ADDR16_HIGHESTA:
675 writeInt16BE(LocalAddress, applyPPChighesta(Value + Addend));
677 case ELF::R_PPC64_ADDR14: {
678 assert(((Value + Addend) & 3) == 0);
679 // Preserve the AA/LK bits in the branch instruction
680 uint8_t aalk = *(LocalAddress + 3);
681 writeInt16BE(LocalAddress + 2, (aalk & 3) | ((Value + Addend) & 0xfffc));
683 case ELF::R_PPC64_REL16_LO: {
684 uint64_t FinalAddress = (Section.LoadAddress + Offset);
685 uint64_t Delta = Value - FinalAddress + Addend;
686 writeInt16BE(LocalAddress, applyPPClo(Delta));
688 case ELF::R_PPC64_REL16_HI: {
689 uint64_t FinalAddress = (Section.LoadAddress + Offset);
690 uint64_t Delta = Value - FinalAddress + Addend;
691 writeInt16BE(LocalAddress, applyPPChi(Delta));
693 case ELF::R_PPC64_REL16_HA: {
694 uint64_t FinalAddress = (Section.LoadAddress + Offset);
695 uint64_t Delta = Value - FinalAddress + Addend;
696 writeInt16BE(LocalAddress, applyPPCha(Delta));
698 case ELF::R_PPC64_ADDR32: {
699 int32_t Result = static_cast<int32_t>(Value + Addend);
700 if (SignExtend32<32>(Result) != Result)
701 llvm_unreachable("Relocation R_PPC64_ADDR32 overflow");
702 writeInt32BE(LocalAddress, Result);
704 case ELF::R_PPC64_REL24: {
705 uint64_t FinalAddress = (Section.LoadAddress + Offset);
706 int32_t delta = static_cast<int32_t>(Value - FinalAddress + Addend);
707 if (SignExtend32<24>(delta) != delta)
708 llvm_unreachable("Relocation R_PPC64_REL24 overflow");
709 // Generates a 'bl <address>' instruction
710 writeInt32BE(LocalAddress, 0x48000001 | (delta & 0x03FFFFFC));
712 case ELF::R_PPC64_REL32: {
713 uint64_t FinalAddress = (Section.LoadAddress + Offset);
714 int32_t delta = static_cast<int32_t>(Value - FinalAddress + Addend);
715 if (SignExtend32<32>(delta) != delta)
716 llvm_unreachable("Relocation R_PPC64_REL32 overflow");
717 writeInt32BE(LocalAddress, delta);
719 case ELF::R_PPC64_REL64: {
720 uint64_t FinalAddress = (Section.LoadAddress + Offset);
721 uint64_t Delta = Value - FinalAddress + Addend;
722 writeInt64BE(LocalAddress, Delta);
724 case ELF::R_PPC64_ADDR64:
725 writeInt64BE(LocalAddress, Value + Addend);
730 void RuntimeDyldELF::resolveSystemZRelocation(const SectionEntry &Section,
731 uint64_t Offset, uint64_t Value,
732 uint32_t Type, int64_t Addend) {
733 uint8_t *LocalAddress = Section.Address + Offset;
736 llvm_unreachable("Relocation type not implemented yet!");
738 case ELF::R_390_PC16DBL:
739 case ELF::R_390_PLT16DBL: {
740 int64_t Delta = (Value + Addend) - (Section.LoadAddress + Offset);
741 assert(int16_t(Delta / 2) * 2 == Delta && "R_390_PC16DBL overflow");
742 writeInt16BE(LocalAddress, Delta / 2);
745 case ELF::R_390_PC32DBL:
746 case ELF::R_390_PLT32DBL: {
747 int64_t Delta = (Value + Addend) - (Section.LoadAddress + Offset);
748 assert(int32_t(Delta / 2) * 2 == Delta && "R_390_PC32DBL overflow");
749 writeInt32BE(LocalAddress, Delta / 2);
752 case ELF::R_390_PC32: {
753 int64_t Delta = (Value + Addend) - (Section.LoadAddress + Offset);
754 assert(int32_t(Delta) == Delta && "R_390_PC32 overflow");
755 writeInt32BE(LocalAddress, Delta);
759 writeInt64BE(LocalAddress, Value + Addend);
764 // The target location for the relocation is described by RE.SectionID and
765 // RE.Offset. RE.SectionID can be used to find the SectionEntry. Each
766 // SectionEntry has three members describing its location.
767 // SectionEntry::Address is the address at which the section has been loaded
768 // into memory in the current (host) process. SectionEntry::LoadAddress is the
769 // address that the section will have in the target process.
770 // SectionEntry::ObjAddress is the address of the bits for this section in the
771 // original emitted object image (also in the current address space).
773 // Relocations will be applied as if the section were loaded at
774 // SectionEntry::LoadAddress, but they will be applied at an address based
775 // on SectionEntry::Address. SectionEntry::ObjAddress will be used to refer to
776 // Target memory contents if they are required for value calculations.
778 // The Value parameter here is the load address of the symbol for the
779 // relocation to be applied. For relocations which refer to symbols in the
780 // current object Value will be the LoadAddress of the section in which
781 // the symbol resides (RE.Addend provides additional information about the
782 // symbol location). For external symbols, Value will be the address of the
783 // symbol in the target address space.
784 void RuntimeDyldELF::resolveRelocation(const RelocationEntry &RE,
786 const SectionEntry &Section = Sections[RE.SectionID];
787 return resolveRelocation(Section, RE.Offset, Value, RE.RelType, RE.Addend,
791 void RuntimeDyldELF::resolveRelocation(const SectionEntry &Section,
792 uint64_t Offset, uint64_t Value,
793 uint32_t Type, int64_t Addend,
794 uint64_t SymOffset) {
797 resolveX86_64Relocation(Section, Offset, Value, Type, Addend, SymOffset);
800 resolveX86Relocation(Section, Offset, (uint32_t)(Value & 0xffffffffL), Type,
801 (uint32_t)(Addend & 0xffffffffL));
803 case Triple::aarch64:
804 case Triple::aarch64_be:
805 resolveAArch64Relocation(Section, Offset, Value, Type, Addend);
807 case Triple::arm: // Fall through.
810 case Triple::thumbeb:
811 resolveARMRelocation(Section, Offset, (uint32_t)(Value & 0xffffffffL), Type,
812 (uint32_t)(Addend & 0xffffffffL));
814 case Triple::mips: // Fall through.
816 resolveMIPSRelocation(Section, Offset, (uint32_t)(Value & 0xffffffffL),
817 Type, (uint32_t)(Addend & 0xffffffffL));
819 case Triple::ppc64: // Fall through.
820 case Triple::ppc64le:
821 resolvePPC64Relocation(Section, Offset, Value, Type, Addend);
823 case Triple::systemz:
824 resolveSystemZRelocation(Section, Offset, Value, Type, Addend);
827 llvm_unreachable("Unsupported CPU type!");
831 void *RuntimeDyldELF::computePlaceholderAddress(unsigned SectionID, uint64_t Offset) const {
832 return (void*)(Sections[SectionID].ObjAddress + Offset);
835 void RuntimeDyldELF::processSimpleRelocation(unsigned SectionID, uint64_t Offset, unsigned RelType, RelocationValueRef Value) {
836 RelocationEntry RE(SectionID, Offset, RelType, Value.Addend, Value.Offset);
837 if (Value.SymbolName)
838 addRelocationForSymbol(RE, Value.SymbolName);
840 addRelocationForSection(RE, Value.SectionID);
843 relocation_iterator RuntimeDyldELF::processRelocationRef(
844 unsigned SectionID, relocation_iterator RelI,
845 const ObjectFile &Obj,
846 ObjSectionToIDMap &ObjSectionToID,
849 Check(RelI->getType(RelType));
851 Check(getELFRelocationAddend(*RelI, Addend));
852 symbol_iterator Symbol = RelI->getSymbol();
854 // Obtain the symbol name which is referenced in the relocation
855 StringRef TargetName;
856 if (Symbol != Obj.symbol_end())
857 Symbol->getName(TargetName);
858 DEBUG(dbgs() << "\t\tRelType: " << RelType << " Addend: " << Addend
859 << " TargetName: " << TargetName << "\n");
860 RelocationValueRef Value;
861 // First search for the symbol in the local symbol table
862 SymbolRef::Type SymType = SymbolRef::ST_Unknown;
864 // Search for the symbol in the global symbol table
865 RTDyldSymbolTable::const_iterator gsi = GlobalSymbolTable.end();
866 if (Symbol != Obj.symbol_end()) {
867 gsi = GlobalSymbolTable.find(TargetName.data());
868 Symbol->getType(SymType);
870 if (gsi != GlobalSymbolTable.end()) {
871 const auto &SymInfo = gsi->second;
872 Value.SectionID = SymInfo.getSectionID();
873 Value.Offset = SymInfo.getOffset();
874 Value.Addend = SymInfo.getOffset() + Addend;
877 case SymbolRef::ST_Debug: {
878 // TODO: Now ELF SymbolRef::ST_Debug = STT_SECTION, it's not obviously
879 // and can be changed by another developers. Maybe best way is add
880 // a new symbol type ST_Section to SymbolRef and use it.
881 section_iterator si(Obj.section_end());
882 Symbol->getSection(si);
883 if (si == Obj.section_end())
884 llvm_unreachable("Symbol section not found, bad object file format!");
885 DEBUG(dbgs() << "\t\tThis is section symbol\n");
886 bool isCode = si->isText();
887 Value.SectionID = findOrEmitSection(Obj, (*si), isCode, ObjSectionToID);
888 Value.Addend = Addend;
891 case SymbolRef::ST_Data:
892 case SymbolRef::ST_Unknown: {
893 Value.SymbolName = TargetName.data();
894 Value.Addend = Addend;
896 // Absolute relocations will have a zero symbol ID (STN_UNDEF), which
897 // will manifest here as a NULL symbol name.
898 // We can set this as a valid (but empty) symbol name, and rely
899 // on addRelocationForSymbol to handle this.
900 if (!Value.SymbolName)
901 Value.SymbolName = "";
905 llvm_unreachable("Unresolved symbol type!");
911 Check(RelI->getOffset(Offset));
913 DEBUG(dbgs() << "\t\tSectionID: " << SectionID << " Offset: " << Offset
915 if ((Arch == Triple::aarch64 || Arch == Triple::aarch64_be) &&
916 (RelType == ELF::R_AARCH64_CALL26 || RelType == ELF::R_AARCH64_JUMP26)) {
917 // This is an AArch64 branch relocation, need to use a stub function.
918 DEBUG(dbgs() << "\t\tThis is an AArch64 branch relocation.");
919 SectionEntry &Section = Sections[SectionID];
921 // Look for an existing stub.
922 StubMap::const_iterator i = Stubs.find(Value);
923 if (i != Stubs.end()) {
924 resolveRelocation(Section, Offset, (uint64_t)Section.Address + i->second,
926 DEBUG(dbgs() << " Stub function found\n");
928 // Create a new stub function.
929 DEBUG(dbgs() << " Create a new stub function\n");
930 Stubs[Value] = Section.StubOffset;
931 uint8_t *StubTargetAddr =
932 createStubFunction(Section.Address + Section.StubOffset);
934 RelocationEntry REmovz_g3(SectionID, StubTargetAddr - Section.Address,
935 ELF::R_AARCH64_MOVW_UABS_G3, Value.Addend);
936 RelocationEntry REmovk_g2(SectionID, StubTargetAddr - Section.Address + 4,
937 ELF::R_AARCH64_MOVW_UABS_G2_NC, Value.Addend);
938 RelocationEntry REmovk_g1(SectionID, StubTargetAddr - Section.Address + 8,
939 ELF::R_AARCH64_MOVW_UABS_G1_NC, Value.Addend);
940 RelocationEntry REmovk_g0(SectionID,
941 StubTargetAddr - Section.Address + 12,
942 ELF::R_AARCH64_MOVW_UABS_G0_NC, Value.Addend);
944 if (Value.SymbolName) {
945 addRelocationForSymbol(REmovz_g3, Value.SymbolName);
946 addRelocationForSymbol(REmovk_g2, Value.SymbolName);
947 addRelocationForSymbol(REmovk_g1, Value.SymbolName);
948 addRelocationForSymbol(REmovk_g0, Value.SymbolName);
950 addRelocationForSection(REmovz_g3, Value.SectionID);
951 addRelocationForSection(REmovk_g2, Value.SectionID);
952 addRelocationForSection(REmovk_g1, Value.SectionID);
953 addRelocationForSection(REmovk_g0, Value.SectionID);
955 resolveRelocation(Section, Offset,
956 (uint64_t)Section.Address + Section.StubOffset, RelType,
958 Section.StubOffset += getMaxStubSize();
960 } else if (Arch == Triple::arm) {
961 if (RelType == ELF::R_ARM_PC24 || RelType == ELF::R_ARM_CALL ||
962 RelType == ELF::R_ARM_JUMP24) {
963 // This is an ARM branch relocation, need to use a stub function.
964 DEBUG(dbgs() << "\t\tThis is an ARM branch relocation.");
965 SectionEntry &Section = Sections[SectionID];
967 // Look for an existing stub.
968 StubMap::const_iterator i = Stubs.find(Value);
969 if (i != Stubs.end()) {
970 resolveRelocation(Section, Offset, (uint64_t)Section.Address + i->second,
972 DEBUG(dbgs() << " Stub function found\n");
974 // Create a new stub function.
975 DEBUG(dbgs() << " Create a new stub function\n");
976 Stubs[Value] = Section.StubOffset;
977 uint8_t *StubTargetAddr =
978 createStubFunction(Section.Address + Section.StubOffset);
979 RelocationEntry RE(SectionID, StubTargetAddr - Section.Address,
980 ELF::R_ARM_ABS32, Value.Addend);
981 if (Value.SymbolName)
982 addRelocationForSymbol(RE, Value.SymbolName);
984 addRelocationForSection(RE, Value.SectionID);
986 resolveRelocation(Section, Offset,
987 (uint64_t)Section.Address + Section.StubOffset, RelType,
989 Section.StubOffset += getMaxStubSize();
992 uint32_t *Placeholder =
993 reinterpret_cast<uint32_t*>(computePlaceholderAddress(SectionID, Offset));
994 if (RelType == ELF::R_ARM_PREL31 || RelType == ELF::R_ARM_TARGET1 ||
995 RelType == ELF::R_ARM_ABS32) {
996 Value.Addend += *Placeholder;
997 } else if (RelType == ELF::R_ARM_MOVW_ABS_NC || RelType == ELF::R_ARM_MOVT_ABS) {
998 // See ELF for ARM documentation
999 Value.Addend += (int16_t)((*Placeholder & 0xFFF) | (((*Placeholder >> 16) & 0xF) << 12));
1001 processSimpleRelocation(SectionID, Offset, RelType, Value);
1003 } else if ((Arch == Triple::mipsel || Arch == Triple::mips)) {
1004 uint32_t *Placeholder = reinterpret_cast<uint32_t*>(computePlaceholderAddress(SectionID, Offset));
1005 if (RelType == ELF::R_MIPS_26) {
1006 // This is an Mips branch relocation, need to use a stub function.
1007 DEBUG(dbgs() << "\t\tThis is a Mips branch relocation.");
1008 SectionEntry &Section = Sections[SectionID];
1010 // Extract the addend from the instruction.
1011 // We shift up by two since the Value will be down shifted again
1012 // when applying the relocation.
1013 uint32_t Addend = ((*Placeholder) & 0x03ffffff) << 2;
1015 Value.Addend += Addend;
1017 // Look up for existing stub.
1018 StubMap::const_iterator i = Stubs.find(Value);
1019 if (i != Stubs.end()) {
1020 RelocationEntry RE(SectionID, Offset, RelType, i->second);
1021 addRelocationForSection(RE, SectionID);
1022 DEBUG(dbgs() << " Stub function found\n");
1024 // Create a new stub function.
1025 DEBUG(dbgs() << " Create a new stub function\n");
1026 Stubs[Value] = Section.StubOffset;
1027 uint8_t *StubTargetAddr =
1028 createStubFunction(Section.Address + Section.StubOffset);
1030 // Creating Hi and Lo relocations for the filled stub instructions.
1031 RelocationEntry REHi(SectionID, StubTargetAddr - Section.Address,
1032 ELF::R_MIPS_HI16, Value.Addend);
1033 RelocationEntry RELo(SectionID, StubTargetAddr - Section.Address + 4,
1034 ELF::R_MIPS_LO16, Value.Addend);
1036 if (Value.SymbolName) {
1037 addRelocationForSymbol(REHi, Value.SymbolName);
1038 addRelocationForSymbol(RELo, Value.SymbolName);
1041 addRelocationForSection(REHi, Value.SectionID);
1042 addRelocationForSection(RELo, Value.SectionID);
1045 RelocationEntry RE(SectionID, Offset, RelType, Section.StubOffset);
1046 addRelocationForSection(RE, SectionID);
1047 Section.StubOffset += getMaxStubSize();
1050 if (RelType == ELF::R_MIPS_HI16)
1051 Value.Addend += ((*Placeholder) & 0x0000ffff) << 16;
1052 else if (RelType == ELF::R_MIPS_LO16)
1053 Value.Addend += ((*Placeholder) & 0x0000ffff);
1054 else if (RelType == ELF::R_MIPS_32)
1055 Value.Addend += *Placeholder;
1056 processSimpleRelocation(SectionID, Offset, RelType, Value);
1058 } else if (Arch == Triple::ppc64 || Arch == Triple::ppc64le) {
1059 if (RelType == ELF::R_PPC64_REL24) {
1060 // Determine ABI variant in use for this object.
1061 unsigned AbiVariant;
1062 Obj.getPlatformFlags(AbiVariant);
1063 AbiVariant &= ELF::EF_PPC64_ABI;
1064 // A PPC branch relocation will need a stub function if the target is
1065 // an external symbol (Symbol::ST_Unknown) or if the target address
1066 // is not within the signed 24-bits branch address.
1067 SectionEntry &Section = Sections[SectionID];
1068 uint8_t *Target = Section.Address + Offset;
1069 bool RangeOverflow = false;
1070 if (SymType != SymbolRef::ST_Unknown) {
1071 if (AbiVariant != 2) {
1072 // In the ELFv1 ABI, a function call may point to the .opd entry,
1073 // so the final symbol value is calculated based on the relocation
1074 // values in the .opd section.
1075 findOPDEntrySection(Obj, ObjSectionToID, Value);
1077 // In the ELFv2 ABI, a function symbol may provide a local entry
1078 // point, which must be used for direct calls.
1080 Symbol->getOther(SymOther);
1081 Value.Addend += ELF::decodePPC64LocalEntryOffset(SymOther);
1083 uint8_t *RelocTarget = Sections[Value.SectionID].Address + Value.Addend;
1084 int32_t delta = static_cast<int32_t>(Target - RelocTarget);
1085 // If it is within 24-bits branch range, just set the branch target
1086 if (SignExtend32<24>(delta) == delta) {
1087 RelocationEntry RE(SectionID, Offset, RelType, Value.Addend);
1088 if (Value.SymbolName)
1089 addRelocationForSymbol(RE, Value.SymbolName);
1091 addRelocationForSection(RE, Value.SectionID);
1093 RangeOverflow = true;
1096 if (SymType == SymbolRef::ST_Unknown || RangeOverflow) {
1097 // It is an external symbol (SymbolRef::ST_Unknown) or within a range
1098 // larger than 24-bits.
1099 StubMap::const_iterator i = Stubs.find(Value);
1100 if (i != Stubs.end()) {
1101 // Symbol function stub already created, just relocate to it
1102 resolveRelocation(Section, Offset,
1103 (uint64_t)Section.Address + i->second, RelType, 0);
1104 DEBUG(dbgs() << " Stub function found\n");
1106 // Create a new stub function.
1107 DEBUG(dbgs() << " Create a new stub function\n");
1108 Stubs[Value] = Section.StubOffset;
1109 uint8_t *StubTargetAddr =
1110 createStubFunction(Section.Address + Section.StubOffset,
1112 RelocationEntry RE(SectionID, StubTargetAddr - Section.Address,
1113 ELF::R_PPC64_ADDR64, Value.Addend);
1115 // Generates the 64-bits address loads as exemplified in section
1116 // 4.5.1 in PPC64 ELF ABI. Note that the relocations need to
1117 // apply to the low part of the instructions, so we have to update
1118 // the offset according to the target endianness.
1119 uint64_t StubRelocOffset = StubTargetAddr - Section.Address;
1120 if (!IsTargetLittleEndian)
1121 StubRelocOffset += 2;
1123 RelocationEntry REhst(SectionID, StubRelocOffset + 0,
1124 ELF::R_PPC64_ADDR16_HIGHEST, Value.Addend);
1125 RelocationEntry REhr(SectionID, StubRelocOffset + 4,
1126 ELF::R_PPC64_ADDR16_HIGHER, Value.Addend);
1127 RelocationEntry REh(SectionID, StubRelocOffset + 12,
1128 ELF::R_PPC64_ADDR16_HI, Value.Addend);
1129 RelocationEntry REl(SectionID, StubRelocOffset + 16,
1130 ELF::R_PPC64_ADDR16_LO, Value.Addend);
1132 if (Value.SymbolName) {
1133 addRelocationForSymbol(REhst, Value.SymbolName);
1134 addRelocationForSymbol(REhr, Value.SymbolName);
1135 addRelocationForSymbol(REh, Value.SymbolName);
1136 addRelocationForSymbol(REl, Value.SymbolName);
1138 addRelocationForSection(REhst, Value.SectionID);
1139 addRelocationForSection(REhr, Value.SectionID);
1140 addRelocationForSection(REh, Value.SectionID);
1141 addRelocationForSection(REl, Value.SectionID);
1144 resolveRelocation(Section, Offset,
1145 (uint64_t)Section.Address + Section.StubOffset,
1147 Section.StubOffset += getMaxStubSize();
1149 if (SymType == SymbolRef::ST_Unknown) {
1150 // Restore the TOC for external calls
1151 if (AbiVariant == 2)
1152 writeInt32BE(Target + 4, 0xE8410018); // ld r2,28(r1)
1154 writeInt32BE(Target + 4, 0xE8410028); // ld r2,40(r1)
1157 } else if (RelType == ELF::R_PPC64_TOC16 ||
1158 RelType == ELF::R_PPC64_TOC16_DS ||
1159 RelType == ELF::R_PPC64_TOC16_LO ||
1160 RelType == ELF::R_PPC64_TOC16_LO_DS ||
1161 RelType == ELF::R_PPC64_TOC16_HI ||
1162 RelType == ELF::R_PPC64_TOC16_HA) {
1163 // These relocations are supposed to subtract the TOC address from
1164 // the final value. This does not fit cleanly into the RuntimeDyld
1165 // scheme, since there may be *two* sections involved in determining
1166 // the relocation value (the section of the symbol refered to by the
1167 // relocation, and the TOC section associated with the current module).
1169 // Fortunately, these relocations are currently only ever generated
1170 // refering to symbols that themselves reside in the TOC, which means
1171 // that the two sections are actually the same. Thus they cancel out
1172 // and we can immediately resolve the relocation right now.
1174 case ELF::R_PPC64_TOC16: RelType = ELF::R_PPC64_ADDR16; break;
1175 case ELF::R_PPC64_TOC16_DS: RelType = ELF::R_PPC64_ADDR16_DS; break;
1176 case ELF::R_PPC64_TOC16_LO: RelType = ELF::R_PPC64_ADDR16_LO; break;
1177 case ELF::R_PPC64_TOC16_LO_DS: RelType = ELF::R_PPC64_ADDR16_LO_DS; break;
1178 case ELF::R_PPC64_TOC16_HI: RelType = ELF::R_PPC64_ADDR16_HI; break;
1179 case ELF::R_PPC64_TOC16_HA: RelType = ELF::R_PPC64_ADDR16_HA; break;
1180 default: llvm_unreachable("Wrong relocation type.");
1183 RelocationValueRef TOCValue;
1184 findPPC64TOCSection(Obj, ObjSectionToID, TOCValue);
1185 if (Value.SymbolName || Value.SectionID != TOCValue.SectionID)
1186 llvm_unreachable("Unsupported TOC relocation.");
1187 Value.Addend -= TOCValue.Addend;
1188 resolveRelocation(Sections[SectionID], Offset, Value.Addend, RelType, 0);
1190 // There are two ways to refer to the TOC address directly: either
1191 // via a ELF::R_PPC64_TOC relocation (where both symbol and addend are
1192 // ignored), or via any relocation that refers to the magic ".TOC."
1193 // symbols (in which case the addend is respected).
1194 if (RelType == ELF::R_PPC64_TOC) {
1195 RelType = ELF::R_PPC64_ADDR64;
1196 findPPC64TOCSection(Obj, ObjSectionToID, Value);
1197 } else if (TargetName == ".TOC.") {
1198 findPPC64TOCSection(Obj, ObjSectionToID, Value);
1199 Value.Addend += Addend;
1202 RelocationEntry RE(SectionID, Offset, RelType, Value.Addend);
1204 if (Value.SymbolName)
1205 addRelocationForSymbol(RE, Value.SymbolName);
1207 addRelocationForSection(RE, Value.SectionID);
1209 } else if (Arch == Triple::systemz &&
1210 (RelType == ELF::R_390_PLT32DBL || RelType == ELF::R_390_GOTENT)) {
1211 // Create function stubs for both PLT and GOT references, regardless of
1212 // whether the GOT reference is to data or code. The stub contains the
1213 // full address of the symbol, as needed by GOT references, and the
1214 // executable part only adds an overhead of 8 bytes.
1216 // We could try to conserve space by allocating the code and data
1217 // parts of the stub separately. However, as things stand, we allocate
1218 // a stub for every relocation, so using a GOT in JIT code should be
1219 // no less space efficient than using an explicit constant pool.
1220 DEBUG(dbgs() << "\t\tThis is a SystemZ indirect relocation.");
1221 SectionEntry &Section = Sections[SectionID];
1223 // Look for an existing stub.
1224 StubMap::const_iterator i = Stubs.find(Value);
1225 uintptr_t StubAddress;
1226 if (i != Stubs.end()) {
1227 StubAddress = uintptr_t(Section.Address) + i->second;
1228 DEBUG(dbgs() << " Stub function found\n");
1230 // Create a new stub function.
1231 DEBUG(dbgs() << " Create a new stub function\n");
1233 uintptr_t BaseAddress = uintptr_t(Section.Address);
1234 uintptr_t StubAlignment = getStubAlignment();
1235 StubAddress = (BaseAddress + Section.StubOffset + StubAlignment - 1) &
1237 unsigned StubOffset = StubAddress - BaseAddress;
1239 Stubs[Value] = StubOffset;
1240 createStubFunction((uint8_t *)StubAddress);
1241 RelocationEntry RE(SectionID, StubOffset + 8, ELF::R_390_64,
1243 if (Value.SymbolName)
1244 addRelocationForSymbol(RE, Value.SymbolName);
1246 addRelocationForSection(RE, Value.SectionID);
1247 Section.StubOffset = StubOffset + getMaxStubSize();
1250 if (RelType == ELF::R_390_GOTENT)
1251 resolveRelocation(Section, Offset, StubAddress + 8, ELF::R_390_PC32DBL,
1254 resolveRelocation(Section, Offset, StubAddress, RelType, Addend);
1255 } else if (Arch == Triple::x86_64) {
1256 if (RelType == ELF::R_X86_64_PLT32) {
1257 // The way the PLT relocations normally work is that the linker allocates
1259 // PLT and this relocation makes a PC-relative call into the PLT. The PLT
1260 // entry will then jump to an address provided by the GOT. On first call,
1262 // GOT address will point back into PLT code that resolves the symbol. After
1263 // the first call, the GOT entry points to the actual function.
1265 // For local functions we're ignoring all of that here and just replacing
1266 // the PLT32 relocation type with PC32, which will translate the relocation
1267 // into a PC-relative call directly to the function. For external symbols we
1268 // can't be sure the function will be within 2^32 bytes of the call site, so
1269 // we need to create a stub, which calls into the GOT. This case is
1270 // equivalent to the usual PLT implementation except that we use the stub
1271 // mechanism in RuntimeDyld (which puts stubs at the end of the section)
1272 // rather than allocating a PLT section.
1273 if (Value.SymbolName) {
1274 // This is a call to an external function.
1275 // Look for an existing stub.
1276 SectionEntry &Section = Sections[SectionID];
1277 StubMap::const_iterator i = Stubs.find(Value);
1278 uintptr_t StubAddress;
1279 if (i != Stubs.end()) {
1280 StubAddress = uintptr_t(Section.Address) + i->second;
1281 DEBUG(dbgs() << " Stub function found\n");
1283 // Create a new stub function (equivalent to a PLT entry).
1284 DEBUG(dbgs() << " Create a new stub function\n");
1286 uintptr_t BaseAddress = uintptr_t(Section.Address);
1287 uintptr_t StubAlignment = getStubAlignment();
1288 StubAddress = (BaseAddress + Section.StubOffset + StubAlignment - 1) &
1290 unsigned StubOffset = StubAddress - BaseAddress;
1291 Stubs[Value] = StubOffset;
1292 createStubFunction((uint8_t *)StubAddress);
1294 // Bump our stub offset counter
1295 Section.StubOffset = StubOffset + getMaxStubSize();
1297 // Allocate a GOT Entry
1298 uint64_t GOTOffset = allocateGOTEntries(SectionID, 1);
1300 // The load of the GOT address has an addend of -4
1301 resolveGOTOffsetRelocation(SectionID, StubOffset + 2, GOTOffset - 4);
1303 // Fill in the value of the symbol we're targeting into the GOT
1304 addRelocationForSymbol(computeGOTOffsetRE(SectionID,GOTOffset,0,ELF::R_X86_64_64),
1308 // Make the target call a call into the stub table.
1309 resolveRelocation(Section, Offset, StubAddress, ELF::R_X86_64_PC32,
1312 RelocationEntry RE(SectionID, Offset, ELF::R_X86_64_PC32, Value.Addend,
1314 addRelocationForSection(RE, Value.SectionID);
1316 } else if (RelType == ELF::R_X86_64_GOTPCREL) {
1317 uint64_t GOTOffset = allocateGOTEntries(SectionID, 1);
1318 resolveGOTOffsetRelocation(SectionID, Offset, GOTOffset + Addend);
1320 // Fill in the value of the symbol we're targeting into the GOT
1321 RelocationEntry RE = computeGOTOffsetRE(SectionID, GOTOffset, Value.Offset, ELF::R_X86_64_64);
1322 if (Value.SymbolName)
1323 addRelocationForSymbol(RE, Value.SymbolName);
1325 addRelocationForSection(RE, Value.SectionID);
1326 } else if (RelType == ELF::R_X86_64_PC32) {
1327 Value.Addend += support::ulittle32_t::ref(computePlaceholderAddress(SectionID, Offset));
1328 processSimpleRelocation(SectionID, Offset, RelType, Value);
1329 } else if (RelType == ELF::R_X86_64_PC64) {
1330 Value.Addend += support::ulittle64_t::ref(computePlaceholderAddress(SectionID, Offset));
1331 processSimpleRelocation(SectionID, Offset, RelType, Value);
1333 processSimpleRelocation(SectionID, Offset, RelType, Value);
1336 if (Arch == Triple::x86) {
1337 Value.Addend += support::ulittle32_t::ref(computePlaceholderAddress(SectionID, Offset));
1339 processSimpleRelocation(SectionID, Offset, RelType, Value);
1344 size_t RuntimeDyldELF::getGOTEntrySize() {
1345 // We don't use the GOT in all of these cases, but it's essentially free
1346 // to put them all here.
1349 case Triple::x86_64:
1350 case Triple::aarch64:
1351 case Triple::aarch64_be:
1353 case Triple::ppc64le:
1354 case Triple::systemz:
1355 Result = sizeof(uint64_t);
1361 case Triple::mipsel:
1362 Result = sizeof(uint32_t);
1365 llvm_unreachable("Unsupported CPU type!");
1370 uint64_t RuntimeDyldELF::allocateGOTEntries(unsigned SectionID, unsigned no)
1372 (void)SectionID; // The GOT Section is the same for all section in the object file
1373 if (GOTSectionID == 0) {
1374 GOTSectionID = Sections.size();
1375 // Reserve a section id. We'll allocate the section later
1376 // once we know the total size
1377 Sections.push_back(SectionEntry(".got", 0, 0, 0));
1379 uint64_t StartOffset = CurrentGOTIndex * getGOTEntrySize();
1380 CurrentGOTIndex += no;
1384 void RuntimeDyldELF::resolveGOTOffsetRelocation(unsigned SectionID, uint64_t Offset, uint64_t GOTOffset)
1386 // Fill in the relative address of the GOT Entry into the stub
1387 RelocationEntry GOTRE(SectionID, Offset, ELF::R_X86_64_PC32, GOTOffset);
1388 addRelocationForSection(GOTRE, GOTSectionID);
1391 RelocationEntry RuntimeDyldELF::computeGOTOffsetRE(unsigned SectionID, uint64_t GOTOffset, uint64_t SymbolOffset,
1394 (void)SectionID; // The GOT Section is the same for all section in the object file
1395 return RelocationEntry(GOTSectionID, GOTOffset, Type, SymbolOffset);
1398 void RuntimeDyldELF::finalizeLoad(const ObjectFile &Obj,
1399 ObjSectionToIDMap &SectionMap) {
1400 // If necessary, allocate the global offset table
1401 if (GOTSectionID != 0) {
1402 // Allocate memory for the section
1403 size_t TotalSize = CurrentGOTIndex * getGOTEntrySize();
1404 uint8_t *Addr = MemMgr.allocateDataSection(TotalSize, getGOTEntrySize(),
1405 GOTSectionID, ".got", false);
1407 report_fatal_error("Unable to allocate memory for GOT!");
1409 Sections[GOTSectionID] = SectionEntry(".got", Addr, TotalSize, 0);
1412 Checker->registerSection(Obj.getFileName(), GOTSectionID);
1414 // For now, initialize all GOT entries to zero. We'll fill them in as
1415 // needed when GOT-based relocations are applied.
1416 memset(Addr, 0, TotalSize);
1419 // Look for and record the EH frame section.
1420 ObjSectionToIDMap::iterator i, e;
1421 for (i = SectionMap.begin(), e = SectionMap.end(); i != e; ++i) {
1422 const SectionRef &Section = i->first;
1424 Section.getName(Name);
1425 if (Name == ".eh_frame") {
1426 UnregisteredEHFrameSections.push_back(i->second);
1432 CurrentGOTIndex = 0;
1435 bool RuntimeDyldELF::isCompatibleFile(const object::ObjectFile &Obj) const {