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;
117 template <typename ELFT>
118 std::unique_ptr<DyldELFObject<ELFT>>
119 createRTDyldELFObject(MemoryBufferRef Buffer,
120 const LoadedELFObjectInfo &L,
121 std::error_code &ec) {
122 typedef typename ELFFile<ELFT>::Elf_Shdr Elf_Shdr;
123 typedef typename ELFDataTypeTypedefHelper<ELFT>::value_type addr_type;
125 std::unique_ptr<DyldELFObject<ELFT>> Obj =
126 llvm::make_unique<DyldELFObject<ELFT>>(Buffer, ec);
128 // Iterate over all sections in the object.
129 for (const auto &Sec : Obj->sections()) {
130 StringRef SectionName;
131 Sec.getName(SectionName);
132 if (SectionName != "") {
133 DataRefImpl ShdrRef = Sec.getRawDataRefImpl();
134 Elf_Shdr *shdr = const_cast<Elf_Shdr *>(
135 reinterpret_cast<const Elf_Shdr *>(ShdrRef.p));
137 if (uint64_t SecLoadAddr = L.getSectionLoadAddress(SectionName)) {
138 // This assumes that the address passed in matches the target address
139 // bitness. The template-based type cast handles everything else.
140 shdr->sh_addr = static_cast<addr_type>(SecLoadAddr);
148 OwningBinary<ObjectFile> createELFDebugObject(const ObjectFile &Obj,
149 const LoadedELFObjectInfo &L) {
150 assert(Obj.isELF() && "Not an ELF object file.");
152 std::unique_ptr<MemoryBuffer> Buffer =
153 MemoryBuffer::getMemBufferCopy(Obj.getData(), Obj.getFileName());
157 std::unique_ptr<ObjectFile> DebugObj;
158 if (Obj.getBytesInAddress() == 4 && Obj.isLittleEndian()) {
159 typedef ELFType<support::little, 2, false> ELF32LE;
160 DebugObj = createRTDyldELFObject<ELF32LE>(Buffer->getMemBufferRef(), L, ec);
161 } else if (Obj.getBytesInAddress() == 4 && !Obj.isLittleEndian()) {
162 typedef ELFType<support::big, 2, false> ELF32BE;
163 DebugObj = createRTDyldELFObject<ELF32BE>(Buffer->getMemBufferRef(), L, ec);
164 } else if (Obj.getBytesInAddress() == 8 && !Obj.isLittleEndian()) {
165 typedef ELFType<support::big, 2, true> ELF64BE;
166 DebugObj = createRTDyldELFObject<ELF64BE>(Buffer->getMemBufferRef(), L, ec);
167 } else if (Obj.getBytesInAddress() == 8 && Obj.isLittleEndian()) {
168 typedef ELFType<support::little, 2, true> ELF64LE;
169 DebugObj = createRTDyldELFObject<ELF64LE>(Buffer->getMemBufferRef(), L, ec);
171 llvm_unreachable("Unexpected ELF format");
173 assert(!ec && "Could not construct copy ELF object file");
175 return OwningBinary<ObjectFile>(std::move(DebugObj), std::move(Buffer));
178 OwningBinary<ObjectFile>
179 LoadedELFObjectInfo::getObjectForDebug(const ObjectFile &Obj) const {
180 return createELFDebugObject(Obj, *this);
187 RuntimeDyldELF::RuntimeDyldELF(RuntimeDyld::MemoryManager &MemMgr,
188 RuntimeDyld::SymbolResolver &Resolver)
189 : RuntimeDyldImpl(MemMgr, Resolver), GOTSectionID(0), CurrentGOTIndex(0) {}
190 RuntimeDyldELF::~RuntimeDyldELF() {}
192 void RuntimeDyldELF::registerEHFrames() {
193 for (int i = 0, e = UnregisteredEHFrameSections.size(); i != e; ++i) {
194 SID EHFrameSID = UnregisteredEHFrameSections[i];
195 uint8_t *EHFrameAddr = Sections[EHFrameSID].Address;
196 uint64_t EHFrameLoadAddr = Sections[EHFrameSID].LoadAddress;
197 size_t EHFrameSize = Sections[EHFrameSID].Size;
198 MemMgr.registerEHFrames(EHFrameAddr, EHFrameLoadAddr, EHFrameSize);
199 RegisteredEHFrameSections.push_back(EHFrameSID);
201 UnregisteredEHFrameSections.clear();
204 void RuntimeDyldELF::deregisterEHFrames() {
205 for (int i = 0, e = RegisteredEHFrameSections.size(); i != e; ++i) {
206 SID EHFrameSID = RegisteredEHFrameSections[i];
207 uint8_t *EHFrameAddr = Sections[EHFrameSID].Address;
208 uint64_t EHFrameLoadAddr = Sections[EHFrameSID].LoadAddress;
209 size_t EHFrameSize = Sections[EHFrameSID].Size;
210 MemMgr.deregisterEHFrames(EHFrameAddr, EHFrameLoadAddr, EHFrameSize);
212 RegisteredEHFrameSections.clear();
215 std::unique_ptr<RuntimeDyld::LoadedObjectInfo>
216 RuntimeDyldELF::loadObject(const object::ObjectFile &O) {
217 unsigned SectionStartIdx, SectionEndIdx;
218 std::tie(SectionStartIdx, SectionEndIdx) = loadObjectImpl(O);
219 return llvm::make_unique<LoadedELFObjectInfo>(*this, SectionStartIdx,
223 void RuntimeDyldELF::resolveX86_64Relocation(const SectionEntry &Section,
224 uint64_t Offset, uint64_t Value,
225 uint32_t Type, int64_t Addend,
226 uint64_t SymOffset) {
229 llvm_unreachable("Relocation type not implemented yet!");
231 case ELF::R_X86_64_64: {
232 support::ulittle64_t::ref(Section.Address + Offset) = Value + Addend;
233 DEBUG(dbgs() << "Writing " << format("%p", (Value + Addend)) << " at "
234 << format("%p\n", Section.Address + Offset));
237 case ELF::R_X86_64_32:
238 case ELF::R_X86_64_32S: {
240 assert((Type == ELF::R_X86_64_32 && (Value <= UINT32_MAX)) ||
241 (Type == ELF::R_X86_64_32S &&
242 ((int64_t)Value <= INT32_MAX && (int64_t)Value >= INT32_MIN)));
243 uint32_t TruncatedAddr = (Value & 0xFFFFFFFF);
244 support::ulittle32_t::ref(Section.Address + Offset) = TruncatedAddr;
245 DEBUG(dbgs() << "Writing " << format("%p", TruncatedAddr) << " at "
246 << format("%p\n", Section.Address + Offset));
249 case ELF::R_X86_64_PC32: {
250 uint64_t FinalAddress = Section.LoadAddress + Offset;
251 int64_t RealOffset = Value + Addend - FinalAddress;
252 assert(isInt<32>(RealOffset));
253 int32_t TruncOffset = (RealOffset & 0xFFFFFFFF);
254 support::ulittle32_t::ref(Section.Address + Offset) = TruncOffset;
257 case ELF::R_X86_64_PC64: {
258 uint64_t FinalAddress = Section.LoadAddress + Offset;
259 int64_t RealOffset = Value + Addend - FinalAddress;
260 support::ulittle64_t::ref(Section.Address + Offset) = RealOffset;
266 void RuntimeDyldELF::resolveX86Relocation(const SectionEntry &Section,
267 uint64_t Offset, uint32_t Value,
268 uint32_t Type, int32_t Addend) {
270 case ELF::R_386_32: {
271 support::ulittle32_t::ref(Section.Address + Offset) = Value + Addend;
274 case ELF::R_386_PC32: {
275 uint32_t FinalAddress = ((Section.LoadAddress + Offset) & 0xFFFFFFFF);
276 uint32_t RealOffset = Value + Addend - FinalAddress;
277 support::ulittle32_t::ref(Section.Address + Offset) = RealOffset;
281 // There are other relocation types, but it appears these are the
282 // only ones currently used by the LLVM ELF object writer
283 llvm_unreachable("Relocation type not implemented yet!");
288 void RuntimeDyldELF::resolveAArch64Relocation(const SectionEntry &Section,
289 uint64_t Offset, uint64_t Value,
290 uint32_t Type, int64_t Addend) {
291 uint32_t *TargetPtr = reinterpret_cast<uint32_t *>(Section.Address + Offset);
292 uint64_t FinalAddress = Section.LoadAddress + Offset;
294 DEBUG(dbgs() << "resolveAArch64Relocation, LocalAddress: 0x"
295 << format("%llx", Section.Address + Offset)
296 << " FinalAddress: 0x" << format("%llx", FinalAddress)
297 << " Value: 0x" << format("%llx", Value) << " Type: 0x"
298 << format("%x", Type) << " Addend: 0x" << format("%llx", Addend)
303 llvm_unreachable("Relocation type not implemented yet!");
305 case ELF::R_AARCH64_ABS64: {
306 uint64_t *TargetPtr =
307 reinterpret_cast<uint64_t *>(Section.Address + Offset);
308 *TargetPtr = Value + Addend;
311 case ELF::R_AARCH64_PREL32: {
312 uint64_t Result = Value + Addend - FinalAddress;
313 assert(static_cast<int64_t>(Result) >= INT32_MIN &&
314 static_cast<int64_t>(Result) <= UINT32_MAX);
315 *TargetPtr = static_cast<uint32_t>(Result & 0xffffffffU);
318 case ELF::R_AARCH64_CALL26: // fallthrough
319 case ELF::R_AARCH64_JUMP26: {
320 // Operation: S+A-P. Set Call or B immediate value to bits fff_fffc of the
322 uint64_t BranchImm = Value + Addend - FinalAddress;
324 // "Check that -2^27 <= result < 2^27".
325 assert(isInt<28>(BranchImm));
327 // AArch64 code is emitted with .rela relocations. The data already in any
328 // bits affected by the relocation on entry is garbage.
329 *TargetPtr &= 0xfc000000U;
330 // Immediate goes in bits 25:0 of B and BL.
331 *TargetPtr |= static_cast<uint32_t>(BranchImm & 0xffffffcU) >> 2;
334 case ELF::R_AARCH64_MOVW_UABS_G3: {
335 uint64_t Result = Value + Addend;
337 // AArch64 code is emitted with .rela relocations. The data already in any
338 // bits affected by the relocation on entry is garbage.
339 *TargetPtr &= 0xffe0001fU;
340 // Immediate goes in bits 20:5 of MOVZ/MOVK instruction
341 *TargetPtr |= Result >> (48 - 5);
342 // Shift must be "lsl #48", in bits 22:21
343 assert((*TargetPtr >> 21 & 0x3) == 3 && "invalid shift for relocation");
346 case ELF::R_AARCH64_MOVW_UABS_G2_NC: {
347 uint64_t Result = Value + Addend;
349 // AArch64 code is emitted with .rela relocations. The data already in any
350 // bits affected by the relocation on entry is garbage.
351 *TargetPtr &= 0xffe0001fU;
352 // Immediate goes in bits 20:5 of MOVZ/MOVK instruction
353 *TargetPtr |= ((Result & 0xffff00000000ULL) >> (32 - 5));
354 // Shift must be "lsl #32", in bits 22:21
355 assert((*TargetPtr >> 21 & 0x3) == 2 && "invalid shift for relocation");
358 case ELF::R_AARCH64_MOVW_UABS_G1_NC: {
359 uint64_t Result = Value + Addend;
361 // AArch64 code is emitted with .rela relocations. The data already in any
362 // bits affected by the relocation on entry is garbage.
363 *TargetPtr &= 0xffe0001fU;
364 // Immediate goes in bits 20:5 of MOVZ/MOVK instruction
365 *TargetPtr |= ((Result & 0xffff0000U) >> (16 - 5));
366 // Shift must be "lsl #16", in bits 22:2
367 assert((*TargetPtr >> 21 & 0x3) == 1 && "invalid shift for relocation");
370 case ELF::R_AARCH64_MOVW_UABS_G0_NC: {
371 uint64_t Result = Value + Addend;
373 // AArch64 code is emitted with .rela relocations. The data already in any
374 // bits affected by the relocation on entry is garbage.
375 *TargetPtr &= 0xffe0001fU;
376 // Immediate goes in bits 20:5 of MOVZ/MOVK instruction
377 *TargetPtr |= ((Result & 0xffffU) << 5);
378 // Shift must be "lsl #0", in bits 22:21.
379 assert((*TargetPtr >> 21 & 0x3) == 0 && "invalid shift for relocation");
382 case ELF::R_AARCH64_ADR_PREL_PG_HI21: {
383 // Operation: Page(S+A) - Page(P)
385 ((Value + Addend) & ~0xfffULL) - (FinalAddress & ~0xfffULL);
387 // Check that -2^32 <= X < 2^32
388 assert(isInt<33>(Result) && "overflow check failed for relocation");
390 // AArch64 code is emitted with .rela relocations. The data already in any
391 // bits affected by the relocation on entry is garbage.
392 *TargetPtr &= 0x9f00001fU;
393 // Immediate goes in bits 30:29 + 5:23 of ADRP instruction, taken
394 // from bits 32:12 of X.
395 *TargetPtr |= ((Result & 0x3000U) << (29 - 12));
396 *TargetPtr |= ((Result & 0x1ffffc000ULL) >> (14 - 5));
399 case ELF::R_AARCH64_LDST32_ABS_LO12_NC: {
401 uint64_t Result = Value + Addend;
403 // AArch64 code is emitted with .rela relocations. The data already in any
404 // bits affected by the relocation on entry is garbage.
405 *TargetPtr &= 0xffc003ffU;
406 // Immediate goes in bits 21:10 of LD/ST instruction, taken
407 // from bits 11:2 of X
408 *TargetPtr |= ((Result & 0xffc) << (10 - 2));
411 case ELF::R_AARCH64_LDST64_ABS_LO12_NC: {
413 uint64_t Result = Value + Addend;
415 // AArch64 code is emitted with .rela relocations. The data already in any
416 // bits affected by the relocation on entry is garbage.
417 *TargetPtr &= 0xffc003ffU;
418 // Immediate goes in bits 21:10 of LD/ST instruction, taken
419 // from bits 11:3 of X
420 *TargetPtr |= ((Result & 0xff8) << (10 - 3));
426 void RuntimeDyldELF::resolveARMRelocation(const SectionEntry &Section,
427 uint64_t Offset, uint32_t Value,
428 uint32_t Type, int32_t Addend) {
429 // TODO: Add Thumb relocations.
430 uint32_t *TargetPtr = (uint32_t *)(Section.Address + Offset);
431 uint32_t FinalAddress = ((Section.LoadAddress + Offset) & 0xFFFFFFFF);
434 DEBUG(dbgs() << "resolveARMRelocation, LocalAddress: "
435 << Section.Address + Offset
436 << " FinalAddress: " << format("%p", FinalAddress) << " Value: "
437 << format("%x", Value) << " Type: " << format("%x", Type)
438 << " Addend: " << format("%x", Addend) << "\n");
442 llvm_unreachable("Not implemented relocation type!");
444 case ELF::R_ARM_NONE:
446 case ELF::R_ARM_PREL31:
447 case ELF::R_ARM_TARGET1:
448 case ELF::R_ARM_ABS32:
451 // Write first 16 bit of 32 bit value to the mov instruction.
452 // Last 4 bit should be shifted.
453 case ELF::R_ARM_MOVW_ABS_NC:
454 case ELF::R_ARM_MOVT_ABS:
455 if (Type == ELF::R_ARM_MOVW_ABS_NC)
456 Value = Value & 0xFFFF;
457 else if (Type == ELF::R_ARM_MOVT_ABS)
458 Value = (Value >> 16) & 0xFFFF;
459 *TargetPtr &= ~0x000F0FFF;
460 *TargetPtr |= Value & 0xFFF;
461 *TargetPtr |= ((Value >> 12) & 0xF) << 16;
463 // Write 24 bit relative value to the branch instruction.
464 case ELF::R_ARM_PC24: // Fall through.
465 case ELF::R_ARM_CALL: // Fall through.
466 case ELF::R_ARM_JUMP24:
467 int32_t RelValue = static_cast<int32_t>(Value - FinalAddress - 8);
468 RelValue = (RelValue & 0x03FFFFFC) >> 2;
469 assert((*TargetPtr & 0xFFFFFF) == 0xFFFFFE);
470 *TargetPtr &= 0xFF000000;
471 *TargetPtr |= RelValue;
476 void RuntimeDyldELF::resolveMIPSRelocation(const SectionEntry &Section,
477 uint64_t Offset, uint32_t Value,
478 uint32_t Type, int32_t Addend) {
479 uint32_t *TargetPtr = (uint32_t *)(Section.Address + Offset);
482 DEBUG(dbgs() << "resolveMipselocation, LocalAddress: "
483 << Section.Address + Offset << " FinalAddress: "
484 << format("%p", Section.LoadAddress + Offset) << " Value: "
485 << format("%x", Value) << " Type: " << format("%x", Type)
486 << " Addend: " << format("%x", Addend) << "\n");
490 llvm_unreachable("Not implemented relocation type!");
496 *TargetPtr = ((*TargetPtr) & 0xfc000000) | ((Value & 0x0fffffff) >> 2);
498 case ELF::R_MIPS_HI16:
499 // Get the higher 16-bits. Also add 1 if bit 15 is 1.
501 ((*TargetPtr) & 0xffff0000) | (((Value + 0x8000) >> 16) & 0xffff);
503 case ELF::R_MIPS_LO16:
504 *TargetPtr = ((*TargetPtr) & 0xffff0000) | (Value & 0xffff);
509 // Return the .TOC. section and offset.
510 void RuntimeDyldELF::findPPC64TOCSection(const ObjectFile &Obj,
511 ObjSectionToIDMap &LocalSections,
512 RelocationValueRef &Rel) {
513 // Set a default SectionID in case we do not find a TOC section below.
514 // This may happen for references to TOC base base (sym@toc, .odp
515 // relocation) without a .toc directive. In this case just use the
516 // first section (which is usually the .odp) since the code won't
517 // reference the .toc base directly.
518 Rel.SymbolName = NULL;
521 // The TOC consists of sections .got, .toc, .tocbss, .plt in that
522 // order. The TOC starts where the first of these sections starts.
523 for (section_iterator si = Obj.section_begin(), se = Obj.section_end();
526 StringRef SectionName;
527 check(si->getName(SectionName));
529 if (SectionName == ".got"
530 || SectionName == ".toc"
531 || SectionName == ".tocbss"
532 || SectionName == ".plt") {
533 Rel.SectionID = findOrEmitSection(Obj, *si, false, LocalSections);
538 // Per the ppc64-elf-linux ABI, The TOC base is TOC value plus 0x8000
539 // thus permitting a full 64 Kbytes segment.
543 // Returns the sections and offset associated with the ODP entry referenced
545 void RuntimeDyldELF::findOPDEntrySection(const ObjectFile &Obj,
546 ObjSectionToIDMap &LocalSections,
547 RelocationValueRef &Rel) {
548 // Get the ELF symbol value (st_value) to compare with Relocation offset in
550 for (section_iterator si = Obj.section_begin(), se = Obj.section_end();
552 section_iterator RelSecI = si->getRelocatedSection();
553 if (RelSecI == Obj.section_end())
556 StringRef RelSectionName;
557 check(RelSecI->getName(RelSectionName));
558 if (RelSectionName != ".opd")
561 for (relocation_iterator i = si->relocation_begin(),
562 e = si->relocation_end();
564 // The R_PPC64_ADDR64 relocation indicates the first field
567 check(i->getType(TypeFunc));
568 if (TypeFunc != ELF::R_PPC64_ADDR64) {
573 uint64_t TargetSymbolOffset;
574 symbol_iterator TargetSymbol = i->getSymbol();
575 check(i->getOffset(TargetSymbolOffset));
577 check(getELFRelocationAddend(*i, Addend));
583 // Just check if following relocation is a R_PPC64_TOC
585 check(i->getType(TypeTOC));
586 if (TypeTOC != ELF::R_PPC64_TOC)
589 // Finally compares the Symbol value and the target symbol offset
590 // to check if this .opd entry refers to the symbol the relocation
592 if (Rel.Addend != (int64_t)TargetSymbolOffset)
595 section_iterator tsi(Obj.section_end());
596 check(TargetSymbol->getSection(tsi));
597 bool IsCode = tsi->isText();
598 Rel.SectionID = findOrEmitSection(Obj, (*tsi), IsCode, LocalSections);
599 Rel.Addend = (intptr_t)Addend;
603 llvm_unreachable("Attempting to get address of ODP entry!");
606 // Relocation masks following the #lo(value), #hi(value), #ha(value),
607 // #higher(value), #highera(value), #highest(value), and #highesta(value)
608 // macros defined in section 4.5.1. Relocation Types of the PPC-elf64abi
611 static inline uint16_t applyPPClo(uint64_t value) { return value & 0xffff; }
613 static inline uint16_t applyPPChi(uint64_t value) {
614 return (value >> 16) & 0xffff;
617 static inline uint16_t applyPPCha (uint64_t value) {
618 return ((value + 0x8000) >> 16) & 0xffff;
621 static inline uint16_t applyPPChigher(uint64_t value) {
622 return (value >> 32) & 0xffff;
625 static inline uint16_t applyPPChighera (uint64_t value) {
626 return ((value + 0x8000) >> 32) & 0xffff;
629 static inline uint16_t applyPPChighest(uint64_t value) {
630 return (value >> 48) & 0xffff;
633 static inline uint16_t applyPPChighesta (uint64_t value) {
634 return ((value + 0x8000) >> 48) & 0xffff;
637 void RuntimeDyldELF::resolvePPC64Relocation(const SectionEntry &Section,
638 uint64_t Offset, uint64_t Value,
639 uint32_t Type, int64_t Addend) {
640 uint8_t *LocalAddress = Section.Address + Offset;
643 llvm_unreachable("Relocation type not implemented yet!");
645 case ELF::R_PPC64_ADDR16:
646 writeInt16BE(LocalAddress, applyPPClo(Value + Addend));
648 case ELF::R_PPC64_ADDR16_DS:
649 writeInt16BE(LocalAddress, applyPPClo(Value + Addend) & ~3);
651 case ELF::R_PPC64_ADDR16_LO:
652 writeInt16BE(LocalAddress, applyPPClo(Value + Addend));
654 case ELF::R_PPC64_ADDR16_LO_DS:
655 writeInt16BE(LocalAddress, applyPPClo(Value + Addend) & ~3);
657 case ELF::R_PPC64_ADDR16_HI:
658 writeInt16BE(LocalAddress, applyPPChi(Value + Addend));
660 case ELF::R_PPC64_ADDR16_HA:
661 writeInt16BE(LocalAddress, applyPPCha(Value + Addend));
663 case ELF::R_PPC64_ADDR16_HIGHER:
664 writeInt16BE(LocalAddress, applyPPChigher(Value + Addend));
666 case ELF::R_PPC64_ADDR16_HIGHERA:
667 writeInt16BE(LocalAddress, applyPPChighera(Value + Addend));
669 case ELF::R_PPC64_ADDR16_HIGHEST:
670 writeInt16BE(LocalAddress, applyPPChighest(Value + Addend));
672 case ELF::R_PPC64_ADDR16_HIGHESTA:
673 writeInt16BE(LocalAddress, applyPPChighesta(Value + Addend));
675 case ELF::R_PPC64_ADDR14: {
676 assert(((Value + Addend) & 3) == 0);
677 // Preserve the AA/LK bits in the branch instruction
678 uint8_t aalk = *(LocalAddress + 3);
679 writeInt16BE(LocalAddress + 2, (aalk & 3) | ((Value + Addend) & 0xfffc));
681 case ELF::R_PPC64_REL16_LO: {
682 uint64_t FinalAddress = (Section.LoadAddress + Offset);
683 uint64_t Delta = Value - FinalAddress + Addend;
684 writeInt16BE(LocalAddress, applyPPClo(Delta));
686 case ELF::R_PPC64_REL16_HI: {
687 uint64_t FinalAddress = (Section.LoadAddress + Offset);
688 uint64_t Delta = Value - FinalAddress + Addend;
689 writeInt16BE(LocalAddress, applyPPChi(Delta));
691 case ELF::R_PPC64_REL16_HA: {
692 uint64_t FinalAddress = (Section.LoadAddress + Offset);
693 uint64_t Delta = Value - FinalAddress + Addend;
694 writeInt16BE(LocalAddress, applyPPCha(Delta));
696 case ELF::R_PPC64_ADDR32: {
697 int32_t Result = static_cast<int32_t>(Value + Addend);
698 if (SignExtend32<32>(Result) != Result)
699 llvm_unreachable("Relocation R_PPC64_ADDR32 overflow");
700 writeInt32BE(LocalAddress, Result);
702 case ELF::R_PPC64_REL24: {
703 uint64_t FinalAddress = (Section.LoadAddress + Offset);
704 int32_t delta = static_cast<int32_t>(Value - FinalAddress + Addend);
705 if (SignExtend32<24>(delta) != delta)
706 llvm_unreachable("Relocation R_PPC64_REL24 overflow");
707 // Generates a 'bl <address>' instruction
708 writeInt32BE(LocalAddress, 0x48000001 | (delta & 0x03FFFFFC));
710 case ELF::R_PPC64_REL32: {
711 uint64_t FinalAddress = (Section.LoadAddress + Offset);
712 int32_t delta = static_cast<int32_t>(Value - FinalAddress + Addend);
713 if (SignExtend32<32>(delta) != delta)
714 llvm_unreachable("Relocation R_PPC64_REL32 overflow");
715 writeInt32BE(LocalAddress, delta);
717 case ELF::R_PPC64_REL64: {
718 uint64_t FinalAddress = (Section.LoadAddress + Offset);
719 uint64_t Delta = Value - FinalAddress + Addend;
720 writeInt64BE(LocalAddress, Delta);
722 case ELF::R_PPC64_ADDR64:
723 writeInt64BE(LocalAddress, Value + Addend);
728 void RuntimeDyldELF::resolveSystemZRelocation(const SectionEntry &Section,
729 uint64_t Offset, uint64_t Value,
730 uint32_t Type, int64_t Addend) {
731 uint8_t *LocalAddress = Section.Address + Offset;
734 llvm_unreachable("Relocation type not implemented yet!");
736 case ELF::R_390_PC16DBL:
737 case ELF::R_390_PLT16DBL: {
738 int64_t Delta = (Value + Addend) - (Section.LoadAddress + Offset);
739 assert(int16_t(Delta / 2) * 2 == Delta && "R_390_PC16DBL overflow");
740 writeInt16BE(LocalAddress, Delta / 2);
743 case ELF::R_390_PC32DBL:
744 case ELF::R_390_PLT32DBL: {
745 int64_t Delta = (Value + Addend) - (Section.LoadAddress + Offset);
746 assert(int32_t(Delta / 2) * 2 == Delta && "R_390_PC32DBL overflow");
747 writeInt32BE(LocalAddress, Delta / 2);
750 case ELF::R_390_PC32: {
751 int64_t Delta = (Value + Addend) - (Section.LoadAddress + Offset);
752 assert(int32_t(Delta) == Delta && "R_390_PC32 overflow");
753 writeInt32BE(LocalAddress, Delta);
757 writeInt64BE(LocalAddress, Value + Addend);
762 // The target location for the relocation is described by RE.SectionID and
763 // RE.Offset. RE.SectionID can be used to find the SectionEntry. Each
764 // SectionEntry has three members describing its location.
765 // SectionEntry::Address is the address at which the section has been loaded
766 // into memory in the current (host) process. SectionEntry::LoadAddress is the
767 // address that the section will have in the target process.
768 // SectionEntry::ObjAddress is the address of the bits for this section in the
769 // original emitted object image (also in the current address space).
771 // Relocations will be applied as if the section were loaded at
772 // SectionEntry::LoadAddress, but they will be applied at an address based
773 // on SectionEntry::Address. SectionEntry::ObjAddress will be used to refer to
774 // Target memory contents if they are required for value calculations.
776 // The Value parameter here is the load address of the symbol for the
777 // relocation to be applied. For relocations which refer to symbols in the
778 // current object Value will be the LoadAddress of the section in which
779 // the symbol resides (RE.Addend provides additional information about the
780 // symbol location). For external symbols, Value will be the address of the
781 // symbol in the target address space.
782 void RuntimeDyldELF::resolveRelocation(const RelocationEntry &RE,
784 const SectionEntry &Section = Sections[RE.SectionID];
785 return resolveRelocation(Section, RE.Offset, Value, RE.RelType, RE.Addend,
789 void RuntimeDyldELF::resolveRelocation(const SectionEntry &Section,
790 uint64_t Offset, uint64_t Value,
791 uint32_t Type, int64_t Addend,
792 uint64_t SymOffset) {
795 resolveX86_64Relocation(Section, Offset, Value, Type, Addend, SymOffset);
798 resolveX86Relocation(Section, Offset, (uint32_t)(Value & 0xffffffffL), Type,
799 (uint32_t)(Addend & 0xffffffffL));
801 case Triple::aarch64:
802 case Triple::aarch64_be:
803 resolveAArch64Relocation(Section, Offset, Value, Type, Addend);
805 case Triple::arm: // Fall through.
808 case Triple::thumbeb:
809 resolveARMRelocation(Section, Offset, (uint32_t)(Value & 0xffffffffL), Type,
810 (uint32_t)(Addend & 0xffffffffL));
812 case Triple::mips: // Fall through.
814 resolveMIPSRelocation(Section, Offset, (uint32_t)(Value & 0xffffffffL),
815 Type, (uint32_t)(Addend & 0xffffffffL));
817 case Triple::ppc64: // Fall through.
818 case Triple::ppc64le:
819 resolvePPC64Relocation(Section, Offset, Value, Type, Addend);
821 case Triple::systemz:
822 resolveSystemZRelocation(Section, Offset, Value, Type, Addend);
825 llvm_unreachable("Unsupported CPU type!");
829 void *RuntimeDyldELF::computePlaceholderAddress(unsigned SectionID, uint64_t Offset) const {
830 return (void*)(Sections[SectionID].ObjAddress + Offset);
833 void RuntimeDyldELF::processSimpleRelocation(unsigned SectionID, uint64_t Offset, unsigned RelType, RelocationValueRef Value) {
834 RelocationEntry RE(SectionID, Offset, RelType, Value.Addend, Value.Offset);
835 if (Value.SymbolName)
836 addRelocationForSymbol(RE, Value.SymbolName);
838 addRelocationForSection(RE, Value.SectionID);
841 relocation_iterator RuntimeDyldELF::processRelocationRef(
842 unsigned SectionID, relocation_iterator RelI,
843 const ObjectFile &Obj,
844 ObjSectionToIDMap &ObjSectionToID,
847 Check(RelI->getType(RelType));
849 Check(getELFRelocationAddend(*RelI, Addend));
850 symbol_iterator Symbol = RelI->getSymbol();
852 // Obtain the symbol name which is referenced in the relocation
853 StringRef TargetName;
854 if (Symbol != Obj.symbol_end())
855 Symbol->getName(TargetName);
856 DEBUG(dbgs() << "\t\tRelType: " << RelType << " Addend: " << Addend
857 << " TargetName: " << TargetName << "\n");
858 RelocationValueRef Value;
859 // First search for the symbol in the local symbol table
860 SymbolRef::Type SymType = SymbolRef::ST_Unknown;
862 // Search for the symbol in the global symbol table
863 RTDyldSymbolTable::const_iterator gsi = GlobalSymbolTable.end();
864 if (Symbol != Obj.symbol_end()) {
865 gsi = GlobalSymbolTable.find(TargetName.data());
866 Symbol->getType(SymType);
868 if (gsi != GlobalSymbolTable.end()) {
869 const auto &SymInfo = gsi->second;
870 Value.SectionID = SymInfo.getSectionID();
871 Value.Offset = SymInfo.getOffset();
872 Value.Addend = SymInfo.getOffset() + Addend;
875 case SymbolRef::ST_Debug: {
876 // TODO: Now ELF SymbolRef::ST_Debug = STT_SECTION, it's not obviously
877 // and can be changed by another developers. Maybe best way is add
878 // a new symbol type ST_Section to SymbolRef and use it.
879 section_iterator si(Obj.section_end());
880 Symbol->getSection(si);
881 if (si == Obj.section_end())
882 llvm_unreachable("Symbol section not found, bad object file format!");
883 DEBUG(dbgs() << "\t\tThis is section symbol\n");
884 bool isCode = si->isText();
885 Value.SectionID = findOrEmitSection(Obj, (*si), isCode, ObjSectionToID);
886 Value.Addend = Addend;
889 case SymbolRef::ST_Data:
890 case SymbolRef::ST_Unknown: {
891 Value.SymbolName = TargetName.data();
892 Value.Addend = Addend;
894 // Absolute relocations will have a zero symbol ID (STN_UNDEF), which
895 // will manifest here as a NULL symbol name.
896 // We can set this as a valid (but empty) symbol name, and rely
897 // on addRelocationForSymbol to handle this.
898 if (!Value.SymbolName)
899 Value.SymbolName = "";
903 llvm_unreachable("Unresolved symbol type!");
909 Check(RelI->getOffset(Offset));
911 DEBUG(dbgs() << "\t\tSectionID: " << SectionID << " Offset: " << Offset
913 if ((Arch == Triple::aarch64 || Arch == Triple::aarch64_be) &&
914 (RelType == ELF::R_AARCH64_CALL26 || RelType == ELF::R_AARCH64_JUMP26)) {
915 // This is an AArch64 branch relocation, need to use a stub function.
916 DEBUG(dbgs() << "\t\tThis is an AArch64 branch relocation.");
917 SectionEntry &Section = Sections[SectionID];
919 // Look for an existing stub.
920 StubMap::const_iterator i = Stubs.find(Value);
921 if (i != Stubs.end()) {
922 resolveRelocation(Section, Offset, (uint64_t)Section.Address + i->second,
924 DEBUG(dbgs() << " Stub function found\n");
926 // Create a new stub function.
927 DEBUG(dbgs() << " Create a new stub function\n");
928 Stubs[Value] = Section.StubOffset;
929 uint8_t *StubTargetAddr =
930 createStubFunction(Section.Address + Section.StubOffset);
932 RelocationEntry REmovz_g3(SectionID, StubTargetAddr - Section.Address,
933 ELF::R_AARCH64_MOVW_UABS_G3, Value.Addend);
934 RelocationEntry REmovk_g2(SectionID, StubTargetAddr - Section.Address + 4,
935 ELF::R_AARCH64_MOVW_UABS_G2_NC, Value.Addend);
936 RelocationEntry REmovk_g1(SectionID, StubTargetAddr - Section.Address + 8,
937 ELF::R_AARCH64_MOVW_UABS_G1_NC, Value.Addend);
938 RelocationEntry REmovk_g0(SectionID,
939 StubTargetAddr - Section.Address + 12,
940 ELF::R_AARCH64_MOVW_UABS_G0_NC, Value.Addend);
942 if (Value.SymbolName) {
943 addRelocationForSymbol(REmovz_g3, Value.SymbolName);
944 addRelocationForSymbol(REmovk_g2, Value.SymbolName);
945 addRelocationForSymbol(REmovk_g1, Value.SymbolName);
946 addRelocationForSymbol(REmovk_g0, Value.SymbolName);
948 addRelocationForSection(REmovz_g3, Value.SectionID);
949 addRelocationForSection(REmovk_g2, Value.SectionID);
950 addRelocationForSection(REmovk_g1, Value.SectionID);
951 addRelocationForSection(REmovk_g0, Value.SectionID);
953 resolveRelocation(Section, Offset,
954 (uint64_t)Section.Address + Section.StubOffset, RelType,
956 Section.StubOffset += getMaxStubSize();
958 } else if (Arch == Triple::arm) {
959 if (RelType == ELF::R_ARM_PC24 || RelType == ELF::R_ARM_CALL ||
960 RelType == ELF::R_ARM_JUMP24) {
961 // This is an ARM branch relocation, need to use a stub function.
962 DEBUG(dbgs() << "\t\tThis is an ARM branch relocation.");
963 SectionEntry &Section = Sections[SectionID];
965 // Look for an existing stub.
966 StubMap::const_iterator i = Stubs.find(Value);
967 if (i != Stubs.end()) {
968 resolveRelocation(Section, Offset, (uint64_t)Section.Address + i->second,
970 DEBUG(dbgs() << " Stub function found\n");
972 // Create a new stub function.
973 DEBUG(dbgs() << " Create a new stub function\n");
974 Stubs[Value] = Section.StubOffset;
975 uint8_t *StubTargetAddr =
976 createStubFunction(Section.Address + Section.StubOffset);
977 RelocationEntry RE(SectionID, StubTargetAddr - Section.Address,
978 ELF::R_ARM_ABS32, Value.Addend);
979 if (Value.SymbolName)
980 addRelocationForSymbol(RE, Value.SymbolName);
982 addRelocationForSection(RE, Value.SectionID);
984 resolveRelocation(Section, Offset,
985 (uint64_t)Section.Address + Section.StubOffset, RelType,
987 Section.StubOffset += getMaxStubSize();
990 uint32_t *Placeholder =
991 reinterpret_cast<uint32_t*>(computePlaceholderAddress(SectionID, Offset));
992 if (RelType == ELF::R_ARM_PREL31 || RelType == ELF::R_ARM_TARGET1 ||
993 RelType == ELF::R_ARM_ABS32) {
994 Value.Addend += *Placeholder;
995 } else if (RelType == ELF::R_ARM_MOVW_ABS_NC || RelType == ELF::R_ARM_MOVT_ABS) {
996 // See ELF for ARM documentation
997 Value.Addend += (int16_t)((*Placeholder & 0xFFF) | (((*Placeholder >> 16) & 0xF) << 12));
999 processSimpleRelocation(SectionID, Offset, RelType, Value);
1001 } else if ((Arch == Triple::mipsel || Arch == Triple::mips)) {
1002 uint32_t *Placeholder = reinterpret_cast<uint32_t*>(computePlaceholderAddress(SectionID, Offset));
1003 if (RelType == ELF::R_MIPS_26) {
1004 // This is an Mips branch relocation, need to use a stub function.
1005 DEBUG(dbgs() << "\t\tThis is a Mips branch relocation.");
1006 SectionEntry &Section = Sections[SectionID];
1008 // Extract the addend from the instruction.
1009 // We shift up by two since the Value will be down shifted again
1010 // when applying the relocation.
1011 uint32_t Addend = ((*Placeholder) & 0x03ffffff) << 2;
1013 Value.Addend += Addend;
1015 // Look up for existing stub.
1016 StubMap::const_iterator i = Stubs.find(Value);
1017 if (i != Stubs.end()) {
1018 RelocationEntry RE(SectionID, Offset, RelType, i->second);
1019 addRelocationForSection(RE, SectionID);
1020 DEBUG(dbgs() << " Stub function found\n");
1022 // Create a new stub function.
1023 DEBUG(dbgs() << " Create a new stub function\n");
1024 Stubs[Value] = Section.StubOffset;
1025 uint8_t *StubTargetAddr =
1026 createStubFunction(Section.Address + Section.StubOffset);
1028 // Creating Hi and Lo relocations for the filled stub instructions.
1029 RelocationEntry REHi(SectionID, StubTargetAddr - Section.Address,
1030 ELF::R_MIPS_HI16, Value.Addend);
1031 RelocationEntry RELo(SectionID, StubTargetAddr - Section.Address + 4,
1032 ELF::R_MIPS_LO16, Value.Addend);
1034 if (Value.SymbolName) {
1035 addRelocationForSymbol(REHi, Value.SymbolName);
1036 addRelocationForSymbol(RELo, Value.SymbolName);
1039 addRelocationForSection(REHi, Value.SectionID);
1040 addRelocationForSection(RELo, Value.SectionID);
1043 RelocationEntry RE(SectionID, Offset, RelType, Section.StubOffset);
1044 addRelocationForSection(RE, SectionID);
1045 Section.StubOffset += getMaxStubSize();
1048 if (RelType == ELF::R_MIPS_HI16)
1049 Value.Addend += ((*Placeholder) & 0x0000ffff) << 16;
1050 else if (RelType == ELF::R_MIPS_LO16)
1051 Value.Addend += ((*Placeholder) & 0x0000ffff);
1052 else if (RelType == ELF::R_MIPS_32)
1053 Value.Addend += *Placeholder;
1054 processSimpleRelocation(SectionID, Offset, RelType, Value);
1056 } else if (Arch == Triple::ppc64 || Arch == Triple::ppc64le) {
1057 if (RelType == ELF::R_PPC64_REL24) {
1058 // Determine ABI variant in use for this object.
1059 unsigned AbiVariant;
1060 Obj.getPlatformFlags(AbiVariant);
1061 AbiVariant &= ELF::EF_PPC64_ABI;
1062 // A PPC branch relocation will need a stub function if the target is
1063 // an external symbol (Symbol::ST_Unknown) or if the target address
1064 // is not within the signed 24-bits branch address.
1065 SectionEntry &Section = Sections[SectionID];
1066 uint8_t *Target = Section.Address + Offset;
1067 bool RangeOverflow = false;
1068 if (SymType != SymbolRef::ST_Unknown) {
1069 if (AbiVariant != 2) {
1070 // In the ELFv1 ABI, a function call may point to the .opd entry,
1071 // so the final symbol value is calculated based on the relocation
1072 // values in the .opd section.
1073 findOPDEntrySection(Obj, ObjSectionToID, Value);
1075 // In the ELFv2 ABI, a function symbol may provide a local entry
1076 // point, which must be used for direct calls.
1078 Symbol->getOther(SymOther);
1079 Value.Addend += ELF::decodePPC64LocalEntryOffset(SymOther);
1081 uint8_t *RelocTarget = Sections[Value.SectionID].Address + Value.Addend;
1082 int32_t delta = static_cast<int32_t>(Target - RelocTarget);
1083 // If it is within 24-bits branch range, just set the branch target
1084 if (SignExtend32<24>(delta) == delta) {
1085 RelocationEntry RE(SectionID, Offset, RelType, Value.Addend);
1086 if (Value.SymbolName)
1087 addRelocationForSymbol(RE, Value.SymbolName);
1089 addRelocationForSection(RE, Value.SectionID);
1091 RangeOverflow = true;
1094 if (SymType == SymbolRef::ST_Unknown || RangeOverflow) {
1095 // It is an external symbol (SymbolRef::ST_Unknown) or within a range
1096 // larger than 24-bits.
1097 StubMap::const_iterator i = Stubs.find(Value);
1098 if (i != Stubs.end()) {
1099 // Symbol function stub already created, just relocate to it
1100 resolveRelocation(Section, Offset,
1101 (uint64_t)Section.Address + i->second, RelType, 0);
1102 DEBUG(dbgs() << " Stub function found\n");
1104 // Create a new stub function.
1105 DEBUG(dbgs() << " Create a new stub function\n");
1106 Stubs[Value] = Section.StubOffset;
1107 uint8_t *StubTargetAddr =
1108 createStubFunction(Section.Address + Section.StubOffset,
1110 RelocationEntry RE(SectionID, StubTargetAddr - Section.Address,
1111 ELF::R_PPC64_ADDR64, Value.Addend);
1113 // Generates the 64-bits address loads as exemplified in section
1114 // 4.5.1 in PPC64 ELF ABI. Note that the relocations need to
1115 // apply to the low part of the instructions, so we have to update
1116 // the offset according to the target endianness.
1117 uint64_t StubRelocOffset = StubTargetAddr - Section.Address;
1118 if (!IsTargetLittleEndian)
1119 StubRelocOffset += 2;
1121 RelocationEntry REhst(SectionID, StubRelocOffset + 0,
1122 ELF::R_PPC64_ADDR16_HIGHEST, Value.Addend);
1123 RelocationEntry REhr(SectionID, StubRelocOffset + 4,
1124 ELF::R_PPC64_ADDR16_HIGHER, Value.Addend);
1125 RelocationEntry REh(SectionID, StubRelocOffset + 12,
1126 ELF::R_PPC64_ADDR16_HI, Value.Addend);
1127 RelocationEntry REl(SectionID, StubRelocOffset + 16,
1128 ELF::R_PPC64_ADDR16_LO, Value.Addend);
1130 if (Value.SymbolName) {
1131 addRelocationForSymbol(REhst, Value.SymbolName);
1132 addRelocationForSymbol(REhr, Value.SymbolName);
1133 addRelocationForSymbol(REh, Value.SymbolName);
1134 addRelocationForSymbol(REl, Value.SymbolName);
1136 addRelocationForSection(REhst, Value.SectionID);
1137 addRelocationForSection(REhr, Value.SectionID);
1138 addRelocationForSection(REh, Value.SectionID);
1139 addRelocationForSection(REl, Value.SectionID);
1142 resolveRelocation(Section, Offset,
1143 (uint64_t)Section.Address + Section.StubOffset,
1145 Section.StubOffset += getMaxStubSize();
1147 if (SymType == SymbolRef::ST_Unknown) {
1148 // Restore the TOC for external calls
1149 if (AbiVariant == 2)
1150 writeInt32BE(Target + 4, 0xE8410018); // ld r2,28(r1)
1152 writeInt32BE(Target + 4, 0xE8410028); // ld r2,40(r1)
1155 } else if (RelType == ELF::R_PPC64_TOC16 ||
1156 RelType == ELF::R_PPC64_TOC16_DS ||
1157 RelType == ELF::R_PPC64_TOC16_LO ||
1158 RelType == ELF::R_PPC64_TOC16_LO_DS ||
1159 RelType == ELF::R_PPC64_TOC16_HI ||
1160 RelType == ELF::R_PPC64_TOC16_HA) {
1161 // These relocations are supposed to subtract the TOC address from
1162 // the final value. This does not fit cleanly into the RuntimeDyld
1163 // scheme, since there may be *two* sections involved in determining
1164 // the relocation value (the section of the symbol refered to by the
1165 // relocation, and the TOC section associated with the current module).
1167 // Fortunately, these relocations are currently only ever generated
1168 // refering to symbols that themselves reside in the TOC, which means
1169 // that the two sections are actually the same. Thus they cancel out
1170 // and we can immediately resolve the relocation right now.
1172 case ELF::R_PPC64_TOC16: RelType = ELF::R_PPC64_ADDR16; break;
1173 case ELF::R_PPC64_TOC16_DS: RelType = ELF::R_PPC64_ADDR16_DS; break;
1174 case ELF::R_PPC64_TOC16_LO: RelType = ELF::R_PPC64_ADDR16_LO; break;
1175 case ELF::R_PPC64_TOC16_LO_DS: RelType = ELF::R_PPC64_ADDR16_LO_DS; break;
1176 case ELF::R_PPC64_TOC16_HI: RelType = ELF::R_PPC64_ADDR16_HI; break;
1177 case ELF::R_PPC64_TOC16_HA: RelType = ELF::R_PPC64_ADDR16_HA; break;
1178 default: llvm_unreachable("Wrong relocation type.");
1181 RelocationValueRef TOCValue;
1182 findPPC64TOCSection(Obj, ObjSectionToID, TOCValue);
1183 if (Value.SymbolName || Value.SectionID != TOCValue.SectionID)
1184 llvm_unreachable("Unsupported TOC relocation.");
1185 Value.Addend -= TOCValue.Addend;
1186 resolveRelocation(Sections[SectionID], Offset, Value.Addend, RelType, 0);
1188 // There are two ways to refer to the TOC address directly: either
1189 // via a ELF::R_PPC64_TOC relocation (where both symbol and addend are
1190 // ignored), or via any relocation that refers to the magic ".TOC."
1191 // symbols (in which case the addend is respected).
1192 if (RelType == ELF::R_PPC64_TOC) {
1193 RelType = ELF::R_PPC64_ADDR64;
1194 findPPC64TOCSection(Obj, ObjSectionToID, Value);
1195 } else if (TargetName == ".TOC.") {
1196 findPPC64TOCSection(Obj, ObjSectionToID, Value);
1197 Value.Addend += Addend;
1200 RelocationEntry RE(SectionID, Offset, RelType, Value.Addend);
1202 if (Value.SymbolName)
1203 addRelocationForSymbol(RE, Value.SymbolName);
1205 addRelocationForSection(RE, Value.SectionID);
1207 } else if (Arch == Triple::systemz &&
1208 (RelType == ELF::R_390_PLT32DBL || RelType == ELF::R_390_GOTENT)) {
1209 // Create function stubs for both PLT and GOT references, regardless of
1210 // whether the GOT reference is to data or code. The stub contains the
1211 // full address of the symbol, as needed by GOT references, and the
1212 // executable part only adds an overhead of 8 bytes.
1214 // We could try to conserve space by allocating the code and data
1215 // parts of the stub separately. However, as things stand, we allocate
1216 // a stub for every relocation, so using a GOT in JIT code should be
1217 // no less space efficient than using an explicit constant pool.
1218 DEBUG(dbgs() << "\t\tThis is a SystemZ indirect relocation.");
1219 SectionEntry &Section = Sections[SectionID];
1221 // Look for an existing stub.
1222 StubMap::const_iterator i = Stubs.find(Value);
1223 uintptr_t StubAddress;
1224 if (i != Stubs.end()) {
1225 StubAddress = uintptr_t(Section.Address) + i->second;
1226 DEBUG(dbgs() << " Stub function found\n");
1228 // Create a new stub function.
1229 DEBUG(dbgs() << " Create a new stub function\n");
1231 uintptr_t BaseAddress = uintptr_t(Section.Address);
1232 uintptr_t StubAlignment = getStubAlignment();
1233 StubAddress = (BaseAddress + Section.StubOffset + StubAlignment - 1) &
1235 unsigned StubOffset = StubAddress - BaseAddress;
1237 Stubs[Value] = StubOffset;
1238 createStubFunction((uint8_t *)StubAddress);
1239 RelocationEntry RE(SectionID, StubOffset + 8, ELF::R_390_64,
1241 if (Value.SymbolName)
1242 addRelocationForSymbol(RE, Value.SymbolName);
1244 addRelocationForSection(RE, Value.SectionID);
1245 Section.StubOffset = StubOffset + getMaxStubSize();
1248 if (RelType == ELF::R_390_GOTENT)
1249 resolveRelocation(Section, Offset, StubAddress + 8, ELF::R_390_PC32DBL,
1252 resolveRelocation(Section, Offset, StubAddress, RelType, Addend);
1253 } else if (Arch == Triple::x86_64) {
1254 if (RelType == ELF::R_X86_64_PLT32) {
1255 // The way the PLT relocations normally work is that the linker allocates
1257 // PLT and this relocation makes a PC-relative call into the PLT. The PLT
1258 // entry will then jump to an address provided by the GOT. On first call,
1260 // GOT address will point back into PLT code that resolves the symbol. After
1261 // the first call, the GOT entry points to the actual function.
1263 // For local functions we're ignoring all of that here and just replacing
1264 // the PLT32 relocation type with PC32, which will translate the relocation
1265 // into a PC-relative call directly to the function. For external symbols we
1266 // can't be sure the function will be within 2^32 bytes of the call site, so
1267 // we need to create a stub, which calls into the GOT. This case is
1268 // equivalent to the usual PLT implementation except that we use the stub
1269 // mechanism in RuntimeDyld (which puts stubs at the end of the section)
1270 // rather than allocating a PLT section.
1271 if (Value.SymbolName) {
1272 // This is a call to an external function.
1273 // Look for an existing stub.
1274 SectionEntry &Section = Sections[SectionID];
1275 StubMap::const_iterator i = Stubs.find(Value);
1276 uintptr_t StubAddress;
1277 if (i != Stubs.end()) {
1278 StubAddress = uintptr_t(Section.Address) + i->second;
1279 DEBUG(dbgs() << " Stub function found\n");
1281 // Create a new stub function (equivalent to a PLT entry).
1282 DEBUG(dbgs() << " Create a new stub function\n");
1284 uintptr_t BaseAddress = uintptr_t(Section.Address);
1285 uintptr_t StubAlignment = getStubAlignment();
1286 StubAddress = (BaseAddress + Section.StubOffset + StubAlignment - 1) &
1288 unsigned StubOffset = StubAddress - BaseAddress;
1289 Stubs[Value] = StubOffset;
1290 createStubFunction((uint8_t *)StubAddress);
1292 // Bump our stub offset counter
1293 Section.StubOffset = StubOffset + getMaxStubSize();
1295 // Allocate a GOT Entry
1296 uint64_t GOTOffset = allocateGOTEntries(SectionID, 1);
1298 // The load of the GOT address has an addend of -4
1299 resolveGOTOffsetRelocation(SectionID, StubOffset + 2, GOTOffset - 4);
1301 // Fill in the value of the symbol we're targeting into the GOT
1302 addRelocationForSymbol(computeGOTOffsetRE(SectionID,GOTOffset,0,ELF::R_X86_64_64),
1306 // Make the target call a call into the stub table.
1307 resolveRelocation(Section, Offset, StubAddress, ELF::R_X86_64_PC32,
1310 RelocationEntry RE(SectionID, Offset, ELF::R_X86_64_PC32, Value.Addend,
1312 addRelocationForSection(RE, Value.SectionID);
1314 } else if (RelType == ELF::R_X86_64_GOTPCREL) {
1315 uint64_t GOTOffset = allocateGOTEntries(SectionID, 1);
1316 resolveGOTOffsetRelocation(SectionID, Offset, GOTOffset + Addend);
1318 // Fill in the value of the symbol we're targeting into the GOT
1319 RelocationEntry RE = computeGOTOffsetRE(SectionID, GOTOffset, Value.Offset, ELF::R_X86_64_64);
1320 if (Value.SymbolName)
1321 addRelocationForSymbol(RE, Value.SymbolName);
1323 addRelocationForSection(RE, Value.SectionID);
1324 } else if (RelType == ELF::R_X86_64_PC32) {
1325 Value.Addend += support::ulittle32_t::ref(computePlaceholderAddress(SectionID, Offset));
1326 processSimpleRelocation(SectionID, Offset, RelType, Value);
1327 } else if (RelType == ELF::R_X86_64_PC64) {
1328 Value.Addend += support::ulittle64_t::ref(computePlaceholderAddress(SectionID, Offset));
1329 processSimpleRelocation(SectionID, Offset, RelType, Value);
1331 processSimpleRelocation(SectionID, Offset, RelType, Value);
1334 if (Arch == Triple::x86) {
1335 Value.Addend += support::ulittle32_t::ref(computePlaceholderAddress(SectionID, Offset));
1337 processSimpleRelocation(SectionID, Offset, RelType, Value);
1342 size_t RuntimeDyldELF::getGOTEntrySize() {
1343 // We don't use the GOT in all of these cases, but it's essentially free
1344 // to put them all here.
1347 case Triple::x86_64:
1348 case Triple::aarch64:
1349 case Triple::aarch64_be:
1351 case Triple::ppc64le:
1352 case Triple::systemz:
1353 Result = sizeof(uint64_t);
1359 case Triple::mipsel:
1360 Result = sizeof(uint32_t);
1363 llvm_unreachable("Unsupported CPU type!");
1368 uint64_t RuntimeDyldELF::allocateGOTEntries(unsigned SectionID, unsigned no)
1370 (void)SectionID; // The GOT Section is the same for all section in the object file
1371 if (GOTSectionID == 0) {
1372 GOTSectionID = Sections.size();
1373 // Reserve a section id. We'll allocate the section later
1374 // once we know the total size
1375 Sections.push_back(SectionEntry(".got", 0, 0, 0));
1377 uint64_t StartOffset = CurrentGOTIndex * getGOTEntrySize();
1378 CurrentGOTIndex += no;
1382 void RuntimeDyldELF::resolveGOTOffsetRelocation(unsigned SectionID, uint64_t Offset, uint64_t GOTOffset)
1384 // Fill in the relative address of the GOT Entry into the stub
1385 RelocationEntry GOTRE(SectionID, Offset, ELF::R_X86_64_PC32, GOTOffset);
1386 addRelocationForSection(GOTRE, GOTSectionID);
1389 RelocationEntry RuntimeDyldELF::computeGOTOffsetRE(unsigned SectionID, uint64_t GOTOffset, uint64_t SymbolOffset,
1392 (void)SectionID; // The GOT Section is the same for all section in the object file
1393 return RelocationEntry(GOTSectionID, GOTOffset, Type, SymbolOffset);
1396 void RuntimeDyldELF::finalizeLoad(const ObjectFile &Obj,
1397 ObjSectionToIDMap &SectionMap) {
1398 // If necessary, allocate the global offset table
1399 if (GOTSectionID != 0) {
1400 // Allocate memory for the section
1401 size_t TotalSize = CurrentGOTIndex * getGOTEntrySize();
1402 uint8_t *Addr = MemMgr.allocateDataSection(TotalSize, getGOTEntrySize(),
1403 GOTSectionID, ".got", false);
1405 report_fatal_error("Unable to allocate memory for GOT!");
1407 Sections[GOTSectionID] = SectionEntry(".got", Addr, TotalSize, 0);
1410 Checker->registerSection(Obj.getFileName(), GOTSectionID);
1412 // For now, initialize all GOT entries to zero. We'll fill them in as
1413 // needed when GOT-based relocations are applied.
1414 memset(Addr, 0, TotalSize);
1417 // Look for and record the EH frame section.
1418 ObjSectionToIDMap::iterator i, e;
1419 for (i = SectionMap.begin(), e = SectionMap.end(); i != e; ++i) {
1420 const SectionRef &Section = i->first;
1422 Section.getName(Name);
1423 if (Name == ".eh_frame") {
1424 UnregisteredEHFrameSections.push_back(i->second);
1430 CurrentGOTIndex = 0;
1433 bool RuntimeDyldELF::isCompatibleFile(const object::ObjectFile &Obj) const {