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
108 : public RuntimeDyld::LoadedObjectInfoHelper<LoadedELFObjectInfo> {
110 LoadedELFObjectInfo(RuntimeDyldImpl &RTDyld, unsigned BeginIdx,
112 : LoadedObjectInfoHelper(RTDyld, BeginIdx, EndIdx) {}
114 OwningBinary<ObjectFile>
115 getObjectForDebug(const ObjectFile &Obj) const override;
118 template <typename ELFT>
119 std::unique_ptr<DyldELFObject<ELFT>>
120 createRTDyldELFObject(MemoryBufferRef Buffer,
121 const LoadedELFObjectInfo &L,
122 std::error_code &ec) {
123 typedef typename ELFFile<ELFT>::Elf_Shdr Elf_Shdr;
124 typedef typename ELFDataTypeTypedefHelper<ELFT>::value_type addr_type;
126 std::unique_ptr<DyldELFObject<ELFT>> Obj =
127 llvm::make_unique<DyldELFObject<ELFT>>(Buffer, ec);
129 // Iterate over all sections in the object.
130 for (const auto &Sec : Obj->sections()) {
131 StringRef SectionName;
132 Sec.getName(SectionName);
133 if (SectionName != "") {
134 DataRefImpl ShdrRef = Sec.getRawDataRefImpl();
135 Elf_Shdr *shdr = const_cast<Elf_Shdr *>(
136 reinterpret_cast<const Elf_Shdr *>(ShdrRef.p));
138 if (uint64_t SecLoadAddr = L.getSectionLoadAddress(SectionName)) {
139 // This assumes that the address passed in matches the target address
140 // bitness. The template-based type cast handles everything else.
141 shdr->sh_addr = static_cast<addr_type>(SecLoadAddr);
149 OwningBinary<ObjectFile> createELFDebugObject(const ObjectFile &Obj,
150 const LoadedELFObjectInfo &L) {
151 assert(Obj.isELF() && "Not an ELF object file.");
153 std::unique_ptr<MemoryBuffer> Buffer =
154 MemoryBuffer::getMemBufferCopy(Obj.getData(), Obj.getFileName());
158 std::unique_ptr<ObjectFile> DebugObj;
159 if (Obj.getBytesInAddress() == 4 && Obj.isLittleEndian()) {
160 typedef ELFType<support::little, 2, false> ELF32LE;
161 DebugObj = createRTDyldELFObject<ELF32LE>(Buffer->getMemBufferRef(), L, ec);
162 } else if (Obj.getBytesInAddress() == 4 && !Obj.isLittleEndian()) {
163 typedef ELFType<support::big, 2, false> ELF32BE;
164 DebugObj = createRTDyldELFObject<ELF32BE>(Buffer->getMemBufferRef(), L, ec);
165 } else if (Obj.getBytesInAddress() == 8 && !Obj.isLittleEndian()) {
166 typedef ELFType<support::big, 2, true> ELF64BE;
167 DebugObj = createRTDyldELFObject<ELF64BE>(Buffer->getMemBufferRef(), L, ec);
168 } else if (Obj.getBytesInAddress() == 8 && Obj.isLittleEndian()) {
169 typedef ELFType<support::little, 2, true> ELF64LE;
170 DebugObj = createRTDyldELFObject<ELF64LE>(Buffer->getMemBufferRef(), L, ec);
172 llvm_unreachable("Unexpected ELF format");
174 assert(!ec && "Could not construct copy ELF object file");
176 return OwningBinary<ObjectFile>(std::move(DebugObj), std::move(Buffer));
179 OwningBinary<ObjectFile>
180 LoadedELFObjectInfo::getObjectForDebug(const ObjectFile &Obj) const {
181 return createELFDebugObject(Obj, *this);
188 RuntimeDyldELF::RuntimeDyldELF(RuntimeDyld::MemoryManager &MemMgr,
189 RuntimeDyld::SymbolResolver &Resolver)
190 : RuntimeDyldImpl(MemMgr, Resolver), GOTSectionID(0), CurrentGOTIndex(0) {}
191 RuntimeDyldELF::~RuntimeDyldELF() {}
193 void RuntimeDyldELF::registerEHFrames() {
194 for (int i = 0, e = UnregisteredEHFrameSections.size(); i != e; ++i) {
195 SID EHFrameSID = UnregisteredEHFrameSections[i];
196 uint8_t *EHFrameAddr = Sections[EHFrameSID].Address;
197 uint64_t EHFrameLoadAddr = Sections[EHFrameSID].LoadAddress;
198 size_t EHFrameSize = Sections[EHFrameSID].Size;
199 MemMgr.registerEHFrames(EHFrameAddr, EHFrameLoadAddr, EHFrameSize);
200 RegisteredEHFrameSections.push_back(EHFrameSID);
202 UnregisteredEHFrameSections.clear();
205 void RuntimeDyldELF::deregisterEHFrames() {
206 for (int i = 0, e = RegisteredEHFrameSections.size(); i != e; ++i) {
207 SID EHFrameSID = RegisteredEHFrameSections[i];
208 uint8_t *EHFrameAddr = Sections[EHFrameSID].Address;
209 uint64_t EHFrameLoadAddr = Sections[EHFrameSID].LoadAddress;
210 size_t EHFrameSize = Sections[EHFrameSID].Size;
211 MemMgr.deregisterEHFrames(EHFrameAddr, EHFrameLoadAddr, EHFrameSize);
213 RegisteredEHFrameSections.clear();
216 std::unique_ptr<RuntimeDyld::LoadedObjectInfo>
217 RuntimeDyldELF::loadObject(const object::ObjectFile &O) {
218 unsigned SectionStartIdx, SectionEndIdx;
219 std::tie(SectionStartIdx, SectionEndIdx) = loadObjectImpl(O);
220 return llvm::make_unique<LoadedELFObjectInfo>(*this, SectionStartIdx,
224 void RuntimeDyldELF::resolveX86_64Relocation(const SectionEntry &Section,
225 uint64_t Offset, uint64_t Value,
226 uint32_t Type, int64_t Addend,
227 uint64_t SymOffset) {
230 llvm_unreachable("Relocation type not implemented yet!");
232 case ELF::R_X86_64_64: {
233 support::ulittle64_t::ref(Section.Address + Offset) = Value + Addend;
234 DEBUG(dbgs() << "Writing " << format("%p", (Value + Addend)) << " at "
235 << format("%p\n", Section.Address + Offset));
238 case ELF::R_X86_64_32:
239 case ELF::R_X86_64_32S: {
241 assert((Type == ELF::R_X86_64_32 && (Value <= UINT32_MAX)) ||
242 (Type == ELF::R_X86_64_32S &&
243 ((int64_t)Value <= INT32_MAX && (int64_t)Value >= INT32_MIN)));
244 uint32_t TruncatedAddr = (Value & 0xFFFFFFFF);
245 support::ulittle32_t::ref(Section.Address + Offset) = TruncatedAddr;
246 DEBUG(dbgs() << "Writing " << format("%p", TruncatedAddr) << " at "
247 << format("%p\n", Section.Address + Offset));
250 case ELF::R_X86_64_PC32: {
251 uint64_t FinalAddress = Section.LoadAddress + Offset;
252 int64_t RealOffset = Value + Addend - FinalAddress;
253 assert(isInt<32>(RealOffset));
254 int32_t TruncOffset = (RealOffset & 0xFFFFFFFF);
255 support::ulittle32_t::ref(Section.Address + Offset) = TruncOffset;
258 case ELF::R_X86_64_PC64: {
259 uint64_t FinalAddress = Section.LoadAddress + Offset;
260 int64_t RealOffset = Value + Addend - FinalAddress;
261 support::ulittle64_t::ref(Section.Address + Offset) = RealOffset;
267 void RuntimeDyldELF::resolveX86Relocation(const SectionEntry &Section,
268 uint64_t Offset, uint32_t Value,
269 uint32_t Type, int32_t Addend) {
271 case ELF::R_386_32: {
272 support::ulittle32_t::ref(Section.Address + Offset) = Value + Addend;
275 case ELF::R_386_PC32: {
276 uint32_t FinalAddress = ((Section.LoadAddress + Offset) & 0xFFFFFFFF);
277 uint32_t RealOffset = Value + Addend - FinalAddress;
278 support::ulittle32_t::ref(Section.Address + Offset) = RealOffset;
282 // There are other relocation types, but it appears these are the
283 // only ones currently used by the LLVM ELF object writer
284 llvm_unreachable("Relocation type not implemented yet!");
289 void RuntimeDyldELF::resolveAArch64Relocation(const SectionEntry &Section,
290 uint64_t Offset, uint64_t Value,
291 uint32_t Type, int64_t Addend) {
292 uint32_t *TargetPtr = reinterpret_cast<uint32_t *>(Section.Address + Offset);
293 uint64_t FinalAddress = Section.LoadAddress + Offset;
295 DEBUG(dbgs() << "resolveAArch64Relocation, LocalAddress: 0x"
296 << format("%llx", Section.Address + Offset)
297 << " FinalAddress: 0x" << format("%llx", FinalAddress)
298 << " Value: 0x" << format("%llx", Value) << " Type: 0x"
299 << format("%x", Type) << " Addend: 0x" << format("%llx", Addend)
304 llvm_unreachable("Relocation type not implemented yet!");
306 case ELF::R_AARCH64_ABS64: {
307 uint64_t *TargetPtr =
308 reinterpret_cast<uint64_t *>(Section.Address + Offset);
309 *TargetPtr = Value + Addend;
312 case ELF::R_AARCH64_PREL32: {
313 uint64_t Result = Value + Addend - FinalAddress;
314 assert(static_cast<int64_t>(Result) >= INT32_MIN &&
315 static_cast<int64_t>(Result) <= UINT32_MAX);
316 *TargetPtr = static_cast<uint32_t>(Result & 0xffffffffU);
319 case ELF::R_AARCH64_CALL26: // fallthrough
320 case ELF::R_AARCH64_JUMP26: {
321 // Operation: S+A-P. Set Call or B immediate value to bits fff_fffc of the
323 uint64_t BranchImm = Value + Addend - FinalAddress;
325 // "Check that -2^27 <= result < 2^27".
326 assert(isInt<28>(BranchImm));
328 // AArch64 code is emitted with .rela relocations. The data already in any
329 // bits affected by the relocation on entry is garbage.
330 *TargetPtr &= 0xfc000000U;
331 // Immediate goes in bits 25:0 of B and BL.
332 *TargetPtr |= static_cast<uint32_t>(BranchImm & 0xffffffcU) >> 2;
335 case ELF::R_AARCH64_MOVW_UABS_G3: {
336 uint64_t Result = Value + Addend;
338 // AArch64 code is emitted with .rela relocations. The data already in any
339 // bits affected by the relocation on entry is garbage.
340 *TargetPtr &= 0xffe0001fU;
341 // Immediate goes in bits 20:5 of MOVZ/MOVK instruction
342 *TargetPtr |= Result >> (48 - 5);
343 // Shift must be "lsl #48", in bits 22:21
344 assert((*TargetPtr >> 21 & 0x3) == 3 && "invalid shift for relocation");
347 case ELF::R_AARCH64_MOVW_UABS_G2_NC: {
348 uint64_t Result = Value + Addend;
350 // AArch64 code is emitted with .rela relocations. The data already in any
351 // bits affected by the relocation on entry is garbage.
352 *TargetPtr &= 0xffe0001fU;
353 // Immediate goes in bits 20:5 of MOVZ/MOVK instruction
354 *TargetPtr |= ((Result & 0xffff00000000ULL) >> (32 - 5));
355 // Shift must be "lsl #32", in bits 22:21
356 assert((*TargetPtr >> 21 & 0x3) == 2 && "invalid shift for relocation");
359 case ELF::R_AARCH64_MOVW_UABS_G1_NC: {
360 uint64_t Result = Value + Addend;
362 // AArch64 code is emitted with .rela relocations. The data already in any
363 // bits affected by the relocation on entry is garbage.
364 *TargetPtr &= 0xffe0001fU;
365 // Immediate goes in bits 20:5 of MOVZ/MOVK instruction
366 *TargetPtr |= ((Result & 0xffff0000U) >> (16 - 5));
367 // Shift must be "lsl #16", in bits 22:2
368 assert((*TargetPtr >> 21 & 0x3) == 1 && "invalid shift for relocation");
371 case ELF::R_AARCH64_MOVW_UABS_G0_NC: {
372 uint64_t Result = Value + Addend;
374 // AArch64 code is emitted with .rela relocations. The data already in any
375 // bits affected by the relocation on entry is garbage.
376 *TargetPtr &= 0xffe0001fU;
377 // Immediate goes in bits 20:5 of MOVZ/MOVK instruction
378 *TargetPtr |= ((Result & 0xffffU) << 5);
379 // Shift must be "lsl #0", in bits 22:21.
380 assert((*TargetPtr >> 21 & 0x3) == 0 && "invalid shift for relocation");
383 case ELF::R_AARCH64_ADR_PREL_PG_HI21: {
384 // Operation: Page(S+A) - Page(P)
386 ((Value + Addend) & ~0xfffULL) - (FinalAddress & ~0xfffULL);
388 // Check that -2^32 <= X < 2^32
389 assert(isInt<33>(Result) && "overflow check failed for relocation");
391 // AArch64 code is emitted with .rela relocations. The data already in any
392 // bits affected by the relocation on entry is garbage.
393 *TargetPtr &= 0x9f00001fU;
394 // Immediate goes in bits 30:29 + 5:23 of ADRP instruction, taken
395 // from bits 32:12 of X.
396 *TargetPtr |= ((Result & 0x3000U) << (29 - 12));
397 *TargetPtr |= ((Result & 0x1ffffc000ULL) >> (14 - 5));
400 case ELF::R_AARCH64_LDST32_ABS_LO12_NC: {
402 uint64_t Result = Value + Addend;
404 // AArch64 code is emitted with .rela relocations. The data already in any
405 // bits affected by the relocation on entry is garbage.
406 *TargetPtr &= 0xffc003ffU;
407 // Immediate goes in bits 21:10 of LD/ST instruction, taken
408 // from bits 11:2 of X
409 *TargetPtr |= ((Result & 0xffc) << (10 - 2));
412 case ELF::R_AARCH64_LDST64_ABS_LO12_NC: {
414 uint64_t Result = Value + Addend;
416 // AArch64 code is emitted with .rela relocations. The data already in any
417 // bits affected by the relocation on entry is garbage.
418 *TargetPtr &= 0xffc003ffU;
419 // Immediate goes in bits 21:10 of LD/ST instruction, taken
420 // from bits 11:3 of X
421 *TargetPtr |= ((Result & 0xff8) << (10 - 3));
427 void RuntimeDyldELF::resolveARMRelocation(const SectionEntry &Section,
428 uint64_t Offset, uint32_t Value,
429 uint32_t Type, int32_t Addend) {
430 // TODO: Add Thumb relocations.
431 uint32_t *TargetPtr = (uint32_t *)(Section.Address + Offset);
432 uint32_t FinalAddress = ((Section.LoadAddress + Offset) & 0xFFFFFFFF);
435 DEBUG(dbgs() << "resolveARMRelocation, LocalAddress: "
436 << Section.Address + Offset
437 << " FinalAddress: " << format("%p", FinalAddress) << " Value: "
438 << format("%x", Value) << " Type: " << format("%x", Type)
439 << " Addend: " << format("%x", Addend) << "\n");
443 llvm_unreachable("Not implemented relocation type!");
445 case ELF::R_ARM_NONE:
447 case ELF::R_ARM_PREL31:
448 case ELF::R_ARM_TARGET1:
449 case ELF::R_ARM_ABS32:
452 // Write first 16 bit of 32 bit value to the mov instruction.
453 // Last 4 bit should be shifted.
454 case ELF::R_ARM_MOVW_ABS_NC:
455 case ELF::R_ARM_MOVT_ABS:
456 if (Type == ELF::R_ARM_MOVW_ABS_NC)
457 Value = Value & 0xFFFF;
458 else if (Type == ELF::R_ARM_MOVT_ABS)
459 Value = (Value >> 16) & 0xFFFF;
460 *TargetPtr &= ~0x000F0FFF;
461 *TargetPtr |= Value & 0xFFF;
462 *TargetPtr |= ((Value >> 12) & 0xF) << 16;
464 // Write 24 bit relative value to the branch instruction.
465 case ELF::R_ARM_PC24: // Fall through.
466 case ELF::R_ARM_CALL: // Fall through.
467 case ELF::R_ARM_JUMP24:
468 int32_t RelValue = static_cast<int32_t>(Value - FinalAddress - 8);
469 RelValue = (RelValue & 0x03FFFFFC) >> 2;
470 assert((*TargetPtr & 0xFFFFFF) == 0xFFFFFE);
471 *TargetPtr &= 0xFF000000;
472 *TargetPtr |= RelValue;
477 void RuntimeDyldELF::resolveMIPSRelocation(const SectionEntry &Section,
478 uint64_t Offset, uint32_t Value,
479 uint32_t Type, int32_t Addend) {
480 uint32_t *TargetPtr = (uint32_t *)(Section.Address + Offset);
483 DEBUG(dbgs() << "resolveMipselocation, LocalAddress: "
484 << Section.Address + Offset << " FinalAddress: "
485 << format("%p", Section.LoadAddress + Offset) << " Value: "
486 << format("%x", Value) << " Type: " << format("%x", Type)
487 << " Addend: " << format("%x", Addend) << "\n");
491 llvm_unreachable("Not implemented relocation type!");
497 *TargetPtr = ((*TargetPtr) & 0xfc000000) | ((Value & 0x0fffffff) >> 2);
499 case ELF::R_MIPS_HI16:
500 // Get the higher 16-bits. Also add 1 if bit 15 is 1.
502 ((*TargetPtr) & 0xffff0000) | (((Value + 0x8000) >> 16) & 0xffff);
504 case ELF::R_MIPS_LO16:
505 *TargetPtr = ((*TargetPtr) & 0xffff0000) | (Value & 0xffff);
510 // Return the .TOC. section and offset.
511 void RuntimeDyldELF::findPPC64TOCSection(const ObjectFile &Obj,
512 ObjSectionToIDMap &LocalSections,
513 RelocationValueRef &Rel) {
514 // Set a default SectionID in case we do not find a TOC section below.
515 // This may happen for references to TOC base base (sym@toc, .odp
516 // relocation) without a .toc directive. In this case just use the
517 // first section (which is usually the .odp) since the code won't
518 // reference the .toc base directly.
519 Rel.SymbolName = NULL;
522 // The TOC consists of sections .got, .toc, .tocbss, .plt in that
523 // order. The TOC starts where the first of these sections starts.
524 for (section_iterator si = Obj.section_begin(), se = Obj.section_end();
527 StringRef SectionName;
528 check(si->getName(SectionName));
530 if (SectionName == ".got"
531 || SectionName == ".toc"
532 || SectionName == ".tocbss"
533 || SectionName == ".plt") {
534 Rel.SectionID = findOrEmitSection(Obj, *si, false, LocalSections);
539 // Per the ppc64-elf-linux ABI, The TOC base is TOC value plus 0x8000
540 // thus permitting a full 64 Kbytes segment.
544 // Returns the sections and offset associated with the ODP entry referenced
546 void RuntimeDyldELF::findOPDEntrySection(const ObjectFile &Obj,
547 ObjSectionToIDMap &LocalSections,
548 RelocationValueRef &Rel) {
549 // Get the ELF symbol value (st_value) to compare with Relocation offset in
551 for (section_iterator si = Obj.section_begin(), se = Obj.section_end();
553 section_iterator RelSecI = si->getRelocatedSection();
554 if (RelSecI == Obj.section_end())
557 StringRef RelSectionName;
558 check(RelSecI->getName(RelSectionName));
559 if (RelSectionName != ".opd")
562 for (relocation_iterator i = si->relocation_begin(),
563 e = si->relocation_end();
565 // The R_PPC64_ADDR64 relocation indicates the first field
568 check(i->getType(TypeFunc));
569 if (TypeFunc != ELF::R_PPC64_ADDR64) {
574 uint64_t TargetSymbolOffset;
575 symbol_iterator TargetSymbol = i->getSymbol();
576 check(i->getOffset(TargetSymbolOffset));
578 check(getELFRelocationAddend(*i, Addend));
584 // Just check if following relocation is a R_PPC64_TOC
586 check(i->getType(TypeTOC));
587 if (TypeTOC != ELF::R_PPC64_TOC)
590 // Finally compares the Symbol value and the target symbol offset
591 // to check if this .opd entry refers to the symbol the relocation
593 if (Rel.Addend != (int64_t)TargetSymbolOffset)
596 section_iterator tsi(Obj.section_end());
597 check(TargetSymbol->getSection(tsi));
598 bool IsCode = tsi->isText();
599 Rel.SectionID = findOrEmitSection(Obj, (*tsi), IsCode, LocalSections);
600 Rel.Addend = (intptr_t)Addend;
604 llvm_unreachable("Attempting to get address of ODP entry!");
607 // Relocation masks following the #lo(value), #hi(value), #ha(value),
608 // #higher(value), #highera(value), #highest(value), and #highesta(value)
609 // macros defined in section 4.5.1. Relocation Types of the PPC-elf64abi
612 static inline uint16_t applyPPClo(uint64_t value) { return value & 0xffff; }
614 static inline uint16_t applyPPChi(uint64_t value) {
615 return (value >> 16) & 0xffff;
618 static inline uint16_t applyPPCha (uint64_t value) {
619 return ((value + 0x8000) >> 16) & 0xffff;
622 static inline uint16_t applyPPChigher(uint64_t value) {
623 return (value >> 32) & 0xffff;
626 static inline uint16_t applyPPChighera (uint64_t value) {
627 return ((value + 0x8000) >> 32) & 0xffff;
630 static inline uint16_t applyPPChighest(uint64_t value) {
631 return (value >> 48) & 0xffff;
634 static inline uint16_t applyPPChighesta (uint64_t value) {
635 return ((value + 0x8000) >> 48) & 0xffff;
638 void RuntimeDyldELF::resolvePPC64Relocation(const SectionEntry &Section,
639 uint64_t Offset, uint64_t Value,
640 uint32_t Type, int64_t Addend) {
641 uint8_t *LocalAddress = Section.Address + Offset;
644 llvm_unreachable("Relocation type not implemented yet!");
646 case ELF::R_PPC64_ADDR16:
647 writeInt16BE(LocalAddress, applyPPClo(Value + Addend));
649 case ELF::R_PPC64_ADDR16_DS:
650 writeInt16BE(LocalAddress, applyPPClo(Value + Addend) & ~3);
652 case ELF::R_PPC64_ADDR16_LO:
653 writeInt16BE(LocalAddress, applyPPClo(Value + Addend));
655 case ELF::R_PPC64_ADDR16_LO_DS:
656 writeInt16BE(LocalAddress, applyPPClo(Value + Addend) & ~3);
658 case ELF::R_PPC64_ADDR16_HI:
659 writeInt16BE(LocalAddress, applyPPChi(Value + Addend));
661 case ELF::R_PPC64_ADDR16_HA:
662 writeInt16BE(LocalAddress, applyPPCha(Value + Addend));
664 case ELF::R_PPC64_ADDR16_HIGHER:
665 writeInt16BE(LocalAddress, applyPPChigher(Value + Addend));
667 case ELF::R_PPC64_ADDR16_HIGHERA:
668 writeInt16BE(LocalAddress, applyPPChighera(Value + Addend));
670 case ELF::R_PPC64_ADDR16_HIGHEST:
671 writeInt16BE(LocalAddress, applyPPChighest(Value + Addend));
673 case ELF::R_PPC64_ADDR16_HIGHESTA:
674 writeInt16BE(LocalAddress, applyPPChighesta(Value + Addend));
676 case ELF::R_PPC64_ADDR14: {
677 assert(((Value + Addend) & 3) == 0);
678 // Preserve the AA/LK bits in the branch instruction
679 uint8_t aalk = *(LocalAddress + 3);
680 writeInt16BE(LocalAddress + 2, (aalk & 3) | ((Value + Addend) & 0xfffc));
682 case ELF::R_PPC64_REL16_LO: {
683 uint64_t FinalAddress = (Section.LoadAddress + Offset);
684 uint64_t Delta = Value - FinalAddress + Addend;
685 writeInt16BE(LocalAddress, applyPPClo(Delta));
687 case ELF::R_PPC64_REL16_HI: {
688 uint64_t FinalAddress = (Section.LoadAddress + Offset);
689 uint64_t Delta = Value - FinalAddress + Addend;
690 writeInt16BE(LocalAddress, applyPPChi(Delta));
692 case ELF::R_PPC64_REL16_HA: {
693 uint64_t FinalAddress = (Section.LoadAddress + Offset);
694 uint64_t Delta = Value - FinalAddress + Addend;
695 writeInt16BE(LocalAddress, applyPPCha(Delta));
697 case ELF::R_PPC64_ADDR32: {
698 int32_t Result = static_cast<int32_t>(Value + Addend);
699 if (SignExtend32<32>(Result) != Result)
700 llvm_unreachable("Relocation R_PPC64_ADDR32 overflow");
701 writeInt32BE(LocalAddress, Result);
703 case ELF::R_PPC64_REL24: {
704 uint64_t FinalAddress = (Section.LoadAddress + Offset);
705 int32_t delta = static_cast<int32_t>(Value - FinalAddress + Addend);
706 if (SignExtend32<24>(delta) != delta)
707 llvm_unreachable("Relocation R_PPC64_REL24 overflow");
708 // Generates a 'bl <address>' instruction
709 writeInt32BE(LocalAddress, 0x48000001 | (delta & 0x03FFFFFC));
711 case ELF::R_PPC64_REL32: {
712 uint64_t FinalAddress = (Section.LoadAddress + Offset);
713 int32_t delta = static_cast<int32_t>(Value - FinalAddress + Addend);
714 if (SignExtend32<32>(delta) != delta)
715 llvm_unreachable("Relocation R_PPC64_REL32 overflow");
716 writeInt32BE(LocalAddress, delta);
718 case ELF::R_PPC64_REL64: {
719 uint64_t FinalAddress = (Section.LoadAddress + Offset);
720 uint64_t Delta = Value - FinalAddress + Addend;
721 writeInt64BE(LocalAddress, Delta);
723 case ELF::R_PPC64_ADDR64:
724 writeInt64BE(LocalAddress, Value + Addend);
729 void RuntimeDyldELF::resolveSystemZRelocation(const SectionEntry &Section,
730 uint64_t Offset, uint64_t Value,
731 uint32_t Type, int64_t Addend) {
732 uint8_t *LocalAddress = Section.Address + Offset;
735 llvm_unreachable("Relocation type not implemented yet!");
737 case ELF::R_390_PC16DBL:
738 case ELF::R_390_PLT16DBL: {
739 int64_t Delta = (Value + Addend) - (Section.LoadAddress + Offset);
740 assert(int16_t(Delta / 2) * 2 == Delta && "R_390_PC16DBL overflow");
741 writeInt16BE(LocalAddress, Delta / 2);
744 case ELF::R_390_PC32DBL:
745 case ELF::R_390_PLT32DBL: {
746 int64_t Delta = (Value + Addend) - (Section.LoadAddress + Offset);
747 assert(int32_t(Delta / 2) * 2 == Delta && "R_390_PC32DBL overflow");
748 writeInt32BE(LocalAddress, Delta / 2);
751 case ELF::R_390_PC32: {
752 int64_t Delta = (Value + Addend) - (Section.LoadAddress + Offset);
753 assert(int32_t(Delta) == Delta && "R_390_PC32 overflow");
754 writeInt32BE(LocalAddress, Delta);
758 writeInt64BE(LocalAddress, Value + Addend);
763 // The target location for the relocation is described by RE.SectionID and
764 // RE.Offset. RE.SectionID can be used to find the SectionEntry. Each
765 // SectionEntry has three members describing its location.
766 // SectionEntry::Address is the address at which the section has been loaded
767 // into memory in the current (host) process. SectionEntry::LoadAddress is the
768 // address that the section will have in the target process.
769 // SectionEntry::ObjAddress is the address of the bits for this section in the
770 // original emitted object image (also in the current address space).
772 // Relocations will be applied as if the section were loaded at
773 // SectionEntry::LoadAddress, but they will be applied at an address based
774 // on SectionEntry::Address. SectionEntry::ObjAddress will be used to refer to
775 // Target memory contents if they are required for value calculations.
777 // The Value parameter here is the load address of the symbol for the
778 // relocation to be applied. For relocations which refer to symbols in the
779 // current object Value will be the LoadAddress of the section in which
780 // the symbol resides (RE.Addend provides additional information about the
781 // symbol location). For external symbols, Value will be the address of the
782 // symbol in the target address space.
783 void RuntimeDyldELF::resolveRelocation(const RelocationEntry &RE,
785 const SectionEntry &Section = Sections[RE.SectionID];
786 return resolveRelocation(Section, RE.Offset, Value, RE.RelType, RE.Addend,
790 void RuntimeDyldELF::resolveRelocation(const SectionEntry &Section,
791 uint64_t Offset, uint64_t Value,
792 uint32_t Type, int64_t Addend,
793 uint64_t SymOffset) {
796 resolveX86_64Relocation(Section, Offset, Value, Type, Addend, SymOffset);
799 resolveX86Relocation(Section, Offset, (uint32_t)(Value & 0xffffffffL), Type,
800 (uint32_t)(Addend & 0xffffffffL));
802 case Triple::aarch64:
803 case Triple::aarch64_be:
804 resolveAArch64Relocation(Section, Offset, Value, Type, Addend);
806 case Triple::arm: // Fall through.
809 case Triple::thumbeb:
810 resolveARMRelocation(Section, Offset, (uint32_t)(Value & 0xffffffffL), Type,
811 (uint32_t)(Addend & 0xffffffffL));
813 case Triple::mips: // Fall through.
815 resolveMIPSRelocation(Section, Offset, (uint32_t)(Value & 0xffffffffL),
816 Type, (uint32_t)(Addend & 0xffffffffL));
818 case Triple::ppc64: // Fall through.
819 case Triple::ppc64le:
820 resolvePPC64Relocation(Section, Offset, Value, Type, Addend);
822 case Triple::systemz:
823 resolveSystemZRelocation(Section, Offset, Value, Type, Addend);
826 llvm_unreachable("Unsupported CPU type!");
830 void *RuntimeDyldELF::computePlaceholderAddress(unsigned SectionID, uint64_t Offset) const {
831 return (void*)(Sections[SectionID].ObjAddress + Offset);
834 void RuntimeDyldELF::processSimpleRelocation(unsigned SectionID, uint64_t Offset, unsigned RelType, RelocationValueRef Value) {
835 RelocationEntry RE(SectionID, Offset, RelType, Value.Addend, Value.Offset);
836 if (Value.SymbolName)
837 addRelocationForSymbol(RE, Value.SymbolName);
839 addRelocationForSection(RE, Value.SectionID);
842 relocation_iterator RuntimeDyldELF::processRelocationRef(
843 unsigned SectionID, relocation_iterator RelI,
844 const ObjectFile &Obj,
845 ObjSectionToIDMap &ObjSectionToID,
848 Check(RelI->getType(RelType));
850 Check(getELFRelocationAddend(*RelI, Addend));
851 symbol_iterator Symbol = RelI->getSymbol();
853 // Obtain the symbol name which is referenced in the relocation
854 StringRef TargetName;
855 if (Symbol != Obj.symbol_end())
856 Symbol->getName(TargetName);
857 DEBUG(dbgs() << "\t\tRelType: " << RelType << " Addend: " << Addend
858 << " TargetName: " << TargetName << "\n");
859 RelocationValueRef Value;
860 // First search for the symbol in the local symbol table
861 SymbolRef::Type SymType = SymbolRef::ST_Unknown;
863 // Search for the symbol in the global symbol table
864 RTDyldSymbolTable::const_iterator gsi = GlobalSymbolTable.end();
865 if (Symbol != Obj.symbol_end()) {
866 gsi = GlobalSymbolTable.find(TargetName.data());
867 Symbol->getType(SymType);
869 if (gsi != GlobalSymbolTable.end()) {
870 const auto &SymInfo = gsi->second;
871 Value.SectionID = SymInfo.getSectionID();
872 Value.Offset = SymInfo.getOffset();
873 Value.Addend = SymInfo.getOffset() + Addend;
876 case SymbolRef::ST_Debug: {
877 // TODO: Now ELF SymbolRef::ST_Debug = STT_SECTION, it's not obviously
878 // and can be changed by another developers. Maybe best way is add
879 // a new symbol type ST_Section to SymbolRef and use it.
880 section_iterator si(Obj.section_end());
881 Symbol->getSection(si);
882 if (si == Obj.section_end())
883 llvm_unreachable("Symbol section not found, bad object file format!");
884 DEBUG(dbgs() << "\t\tThis is section symbol\n");
885 bool isCode = si->isText();
886 Value.SectionID = findOrEmitSection(Obj, (*si), isCode, ObjSectionToID);
887 Value.Addend = Addend;
890 case SymbolRef::ST_Data:
891 case SymbolRef::ST_Unknown: {
892 Value.SymbolName = TargetName.data();
893 Value.Addend = Addend;
895 // Absolute relocations will have a zero symbol ID (STN_UNDEF), which
896 // will manifest here as a NULL symbol name.
897 // We can set this as a valid (but empty) symbol name, and rely
898 // on addRelocationForSymbol to handle this.
899 if (!Value.SymbolName)
900 Value.SymbolName = "";
904 llvm_unreachable("Unresolved symbol type!");
910 Check(RelI->getOffset(Offset));
912 DEBUG(dbgs() << "\t\tSectionID: " << SectionID << " Offset: " << Offset
914 if ((Arch == Triple::aarch64 || Arch == Triple::aarch64_be) &&
915 (RelType == ELF::R_AARCH64_CALL26 || RelType == ELF::R_AARCH64_JUMP26)) {
916 // This is an AArch64 branch relocation, need to use a stub function.
917 DEBUG(dbgs() << "\t\tThis is an AArch64 branch relocation.");
918 SectionEntry &Section = Sections[SectionID];
920 // Look for an existing stub.
921 StubMap::const_iterator i = Stubs.find(Value);
922 if (i != Stubs.end()) {
923 resolveRelocation(Section, Offset, (uint64_t)Section.Address + i->second,
925 DEBUG(dbgs() << " Stub function found\n");
927 // Create a new stub function.
928 DEBUG(dbgs() << " Create a new stub function\n");
929 Stubs[Value] = Section.StubOffset;
930 uint8_t *StubTargetAddr =
931 createStubFunction(Section.Address + Section.StubOffset);
933 RelocationEntry REmovz_g3(SectionID, StubTargetAddr - Section.Address,
934 ELF::R_AARCH64_MOVW_UABS_G3, Value.Addend);
935 RelocationEntry REmovk_g2(SectionID, StubTargetAddr - Section.Address + 4,
936 ELF::R_AARCH64_MOVW_UABS_G2_NC, Value.Addend);
937 RelocationEntry REmovk_g1(SectionID, StubTargetAddr - Section.Address + 8,
938 ELF::R_AARCH64_MOVW_UABS_G1_NC, Value.Addend);
939 RelocationEntry REmovk_g0(SectionID,
940 StubTargetAddr - Section.Address + 12,
941 ELF::R_AARCH64_MOVW_UABS_G0_NC, Value.Addend);
943 if (Value.SymbolName) {
944 addRelocationForSymbol(REmovz_g3, Value.SymbolName);
945 addRelocationForSymbol(REmovk_g2, Value.SymbolName);
946 addRelocationForSymbol(REmovk_g1, Value.SymbolName);
947 addRelocationForSymbol(REmovk_g0, Value.SymbolName);
949 addRelocationForSection(REmovz_g3, Value.SectionID);
950 addRelocationForSection(REmovk_g2, Value.SectionID);
951 addRelocationForSection(REmovk_g1, Value.SectionID);
952 addRelocationForSection(REmovk_g0, Value.SectionID);
954 resolveRelocation(Section, Offset,
955 (uint64_t)Section.Address + Section.StubOffset, RelType,
957 Section.StubOffset += getMaxStubSize();
959 } else if (Arch == Triple::arm) {
960 if (RelType == ELF::R_ARM_PC24 || RelType == ELF::R_ARM_CALL ||
961 RelType == ELF::R_ARM_JUMP24) {
962 // This is an ARM branch relocation, need to use a stub function.
963 DEBUG(dbgs() << "\t\tThis is an ARM branch relocation.");
964 SectionEntry &Section = Sections[SectionID];
966 // Look for an existing stub.
967 StubMap::const_iterator i = Stubs.find(Value);
968 if (i != Stubs.end()) {
969 resolveRelocation(Section, Offset, (uint64_t)Section.Address + i->second,
971 DEBUG(dbgs() << " Stub function found\n");
973 // Create a new stub function.
974 DEBUG(dbgs() << " Create a new stub function\n");
975 Stubs[Value] = Section.StubOffset;
976 uint8_t *StubTargetAddr =
977 createStubFunction(Section.Address + Section.StubOffset);
978 RelocationEntry RE(SectionID, StubTargetAddr - Section.Address,
979 ELF::R_ARM_ABS32, Value.Addend);
980 if (Value.SymbolName)
981 addRelocationForSymbol(RE, Value.SymbolName);
983 addRelocationForSection(RE, Value.SectionID);
985 resolveRelocation(Section, Offset,
986 (uint64_t)Section.Address + Section.StubOffset, RelType,
988 Section.StubOffset += getMaxStubSize();
991 uint32_t *Placeholder =
992 reinterpret_cast<uint32_t*>(computePlaceholderAddress(SectionID, Offset));
993 if (RelType == ELF::R_ARM_PREL31 || RelType == ELF::R_ARM_TARGET1 ||
994 RelType == ELF::R_ARM_ABS32) {
995 Value.Addend += *Placeholder;
996 } else if (RelType == ELF::R_ARM_MOVW_ABS_NC || RelType == ELF::R_ARM_MOVT_ABS) {
997 // See ELF for ARM documentation
998 Value.Addend += (int16_t)((*Placeholder & 0xFFF) | (((*Placeholder >> 16) & 0xF) << 12));
1000 processSimpleRelocation(SectionID, Offset, RelType, Value);
1002 } else if ((Arch == Triple::mipsel || Arch == Triple::mips)) {
1003 uint32_t *Placeholder = reinterpret_cast<uint32_t*>(computePlaceholderAddress(SectionID, Offset));
1004 if (RelType == ELF::R_MIPS_26) {
1005 // This is an Mips branch relocation, need to use a stub function.
1006 DEBUG(dbgs() << "\t\tThis is a Mips branch relocation.");
1007 SectionEntry &Section = Sections[SectionID];
1009 // Extract the addend from the instruction.
1010 // We shift up by two since the Value will be down shifted again
1011 // when applying the relocation.
1012 uint32_t Addend = ((*Placeholder) & 0x03ffffff) << 2;
1014 Value.Addend += Addend;
1016 // Look up for existing stub.
1017 StubMap::const_iterator i = Stubs.find(Value);
1018 if (i != Stubs.end()) {
1019 RelocationEntry RE(SectionID, Offset, RelType, i->second);
1020 addRelocationForSection(RE, SectionID);
1021 DEBUG(dbgs() << " Stub function found\n");
1023 // Create a new stub function.
1024 DEBUG(dbgs() << " Create a new stub function\n");
1025 Stubs[Value] = Section.StubOffset;
1026 uint8_t *StubTargetAddr =
1027 createStubFunction(Section.Address + Section.StubOffset);
1029 // Creating Hi and Lo relocations for the filled stub instructions.
1030 RelocationEntry REHi(SectionID, StubTargetAddr - Section.Address,
1031 ELF::R_MIPS_HI16, Value.Addend);
1032 RelocationEntry RELo(SectionID, StubTargetAddr - Section.Address + 4,
1033 ELF::R_MIPS_LO16, Value.Addend);
1035 if (Value.SymbolName) {
1036 addRelocationForSymbol(REHi, Value.SymbolName);
1037 addRelocationForSymbol(RELo, Value.SymbolName);
1040 addRelocationForSection(REHi, Value.SectionID);
1041 addRelocationForSection(RELo, Value.SectionID);
1044 RelocationEntry RE(SectionID, Offset, RelType, Section.StubOffset);
1045 addRelocationForSection(RE, SectionID);
1046 Section.StubOffset += getMaxStubSize();
1049 if (RelType == ELF::R_MIPS_HI16)
1050 Value.Addend += ((*Placeholder) & 0x0000ffff) << 16;
1051 else if (RelType == ELF::R_MIPS_LO16)
1052 Value.Addend += ((*Placeholder) & 0x0000ffff);
1053 else if (RelType == ELF::R_MIPS_32)
1054 Value.Addend += *Placeholder;
1055 processSimpleRelocation(SectionID, Offset, RelType, Value);
1057 } else if (Arch == Triple::ppc64 || Arch == Triple::ppc64le) {
1058 if (RelType == ELF::R_PPC64_REL24) {
1059 // Determine ABI variant in use for this object.
1060 unsigned AbiVariant;
1061 Obj.getPlatformFlags(AbiVariant);
1062 AbiVariant &= ELF::EF_PPC64_ABI;
1063 // A PPC branch relocation will need a stub function if the target is
1064 // an external symbol (Symbol::ST_Unknown) or if the target address
1065 // is not within the signed 24-bits branch address.
1066 SectionEntry &Section = Sections[SectionID];
1067 uint8_t *Target = Section.Address + Offset;
1068 bool RangeOverflow = false;
1069 if (SymType != SymbolRef::ST_Unknown) {
1070 if (AbiVariant != 2) {
1071 // In the ELFv1 ABI, a function call may point to the .opd entry,
1072 // so the final symbol value is calculated based on the relocation
1073 // values in the .opd section.
1074 findOPDEntrySection(Obj, ObjSectionToID, Value);
1076 // In the ELFv2 ABI, a function symbol may provide a local entry
1077 // point, which must be used for direct calls.
1079 Symbol->getOther(SymOther);
1080 Value.Addend += ELF::decodePPC64LocalEntryOffset(SymOther);
1082 uint8_t *RelocTarget = Sections[Value.SectionID].Address + Value.Addend;
1083 int32_t delta = static_cast<int32_t>(Target - RelocTarget);
1084 // If it is within 24-bits branch range, just set the branch target
1085 if (SignExtend32<24>(delta) == delta) {
1086 RelocationEntry RE(SectionID, Offset, RelType, Value.Addend);
1087 if (Value.SymbolName)
1088 addRelocationForSymbol(RE, Value.SymbolName);
1090 addRelocationForSection(RE, Value.SectionID);
1092 RangeOverflow = true;
1095 if (SymType == SymbolRef::ST_Unknown || RangeOverflow) {
1096 // It is an external symbol (SymbolRef::ST_Unknown) or within a range
1097 // larger than 24-bits.
1098 StubMap::const_iterator i = Stubs.find(Value);
1099 if (i != Stubs.end()) {
1100 // Symbol function stub already created, just relocate to it
1101 resolveRelocation(Section, Offset,
1102 (uint64_t)Section.Address + i->second, RelType, 0);
1103 DEBUG(dbgs() << " Stub function found\n");
1105 // Create a new stub function.
1106 DEBUG(dbgs() << " Create a new stub function\n");
1107 Stubs[Value] = Section.StubOffset;
1108 uint8_t *StubTargetAddr =
1109 createStubFunction(Section.Address + Section.StubOffset,
1111 RelocationEntry RE(SectionID, StubTargetAddr - Section.Address,
1112 ELF::R_PPC64_ADDR64, Value.Addend);
1114 // Generates the 64-bits address loads as exemplified in section
1115 // 4.5.1 in PPC64 ELF ABI. Note that the relocations need to
1116 // apply to the low part of the instructions, so we have to update
1117 // the offset according to the target endianness.
1118 uint64_t StubRelocOffset = StubTargetAddr - Section.Address;
1119 if (!IsTargetLittleEndian)
1120 StubRelocOffset += 2;
1122 RelocationEntry REhst(SectionID, StubRelocOffset + 0,
1123 ELF::R_PPC64_ADDR16_HIGHEST, Value.Addend);
1124 RelocationEntry REhr(SectionID, StubRelocOffset + 4,
1125 ELF::R_PPC64_ADDR16_HIGHER, Value.Addend);
1126 RelocationEntry REh(SectionID, StubRelocOffset + 12,
1127 ELF::R_PPC64_ADDR16_HI, Value.Addend);
1128 RelocationEntry REl(SectionID, StubRelocOffset + 16,
1129 ELF::R_PPC64_ADDR16_LO, Value.Addend);
1131 if (Value.SymbolName) {
1132 addRelocationForSymbol(REhst, Value.SymbolName);
1133 addRelocationForSymbol(REhr, Value.SymbolName);
1134 addRelocationForSymbol(REh, Value.SymbolName);
1135 addRelocationForSymbol(REl, Value.SymbolName);
1137 addRelocationForSection(REhst, Value.SectionID);
1138 addRelocationForSection(REhr, Value.SectionID);
1139 addRelocationForSection(REh, Value.SectionID);
1140 addRelocationForSection(REl, Value.SectionID);
1143 resolveRelocation(Section, Offset,
1144 (uint64_t)Section.Address + Section.StubOffset,
1146 Section.StubOffset += getMaxStubSize();
1148 if (SymType == SymbolRef::ST_Unknown) {
1149 // Restore the TOC for external calls
1150 if (AbiVariant == 2)
1151 writeInt32BE(Target + 4, 0xE8410018); // ld r2,28(r1)
1153 writeInt32BE(Target + 4, 0xE8410028); // ld r2,40(r1)
1156 } else if (RelType == ELF::R_PPC64_TOC16 ||
1157 RelType == ELF::R_PPC64_TOC16_DS ||
1158 RelType == ELF::R_PPC64_TOC16_LO ||
1159 RelType == ELF::R_PPC64_TOC16_LO_DS ||
1160 RelType == ELF::R_PPC64_TOC16_HI ||
1161 RelType == ELF::R_PPC64_TOC16_HA) {
1162 // These relocations are supposed to subtract the TOC address from
1163 // the final value. This does not fit cleanly into the RuntimeDyld
1164 // scheme, since there may be *two* sections involved in determining
1165 // the relocation value (the section of the symbol refered to by the
1166 // relocation, and the TOC section associated with the current module).
1168 // Fortunately, these relocations are currently only ever generated
1169 // refering to symbols that themselves reside in the TOC, which means
1170 // that the two sections are actually the same. Thus they cancel out
1171 // and we can immediately resolve the relocation right now.
1173 case ELF::R_PPC64_TOC16: RelType = ELF::R_PPC64_ADDR16; break;
1174 case ELF::R_PPC64_TOC16_DS: RelType = ELF::R_PPC64_ADDR16_DS; break;
1175 case ELF::R_PPC64_TOC16_LO: RelType = ELF::R_PPC64_ADDR16_LO; break;
1176 case ELF::R_PPC64_TOC16_LO_DS: RelType = ELF::R_PPC64_ADDR16_LO_DS; break;
1177 case ELF::R_PPC64_TOC16_HI: RelType = ELF::R_PPC64_ADDR16_HI; break;
1178 case ELF::R_PPC64_TOC16_HA: RelType = ELF::R_PPC64_ADDR16_HA; break;
1179 default: llvm_unreachable("Wrong relocation type.");
1182 RelocationValueRef TOCValue;
1183 findPPC64TOCSection(Obj, ObjSectionToID, TOCValue);
1184 if (Value.SymbolName || Value.SectionID != TOCValue.SectionID)
1185 llvm_unreachable("Unsupported TOC relocation.");
1186 Value.Addend -= TOCValue.Addend;
1187 resolveRelocation(Sections[SectionID], Offset, Value.Addend, RelType, 0);
1189 // There are two ways to refer to the TOC address directly: either
1190 // via a ELF::R_PPC64_TOC relocation (where both symbol and addend are
1191 // ignored), or via any relocation that refers to the magic ".TOC."
1192 // symbols (in which case the addend is respected).
1193 if (RelType == ELF::R_PPC64_TOC) {
1194 RelType = ELF::R_PPC64_ADDR64;
1195 findPPC64TOCSection(Obj, ObjSectionToID, Value);
1196 } else if (TargetName == ".TOC.") {
1197 findPPC64TOCSection(Obj, ObjSectionToID, Value);
1198 Value.Addend += Addend;
1201 RelocationEntry RE(SectionID, Offset, RelType, Value.Addend);
1203 if (Value.SymbolName)
1204 addRelocationForSymbol(RE, Value.SymbolName);
1206 addRelocationForSection(RE, Value.SectionID);
1208 } else if (Arch == Triple::systemz &&
1209 (RelType == ELF::R_390_PLT32DBL || RelType == ELF::R_390_GOTENT)) {
1210 // Create function stubs for both PLT and GOT references, regardless of
1211 // whether the GOT reference is to data or code. The stub contains the
1212 // full address of the symbol, as needed by GOT references, and the
1213 // executable part only adds an overhead of 8 bytes.
1215 // We could try to conserve space by allocating the code and data
1216 // parts of the stub separately. However, as things stand, we allocate
1217 // a stub for every relocation, so using a GOT in JIT code should be
1218 // no less space efficient than using an explicit constant pool.
1219 DEBUG(dbgs() << "\t\tThis is a SystemZ indirect relocation.");
1220 SectionEntry &Section = Sections[SectionID];
1222 // Look for an existing stub.
1223 StubMap::const_iterator i = Stubs.find(Value);
1224 uintptr_t StubAddress;
1225 if (i != Stubs.end()) {
1226 StubAddress = uintptr_t(Section.Address) + i->second;
1227 DEBUG(dbgs() << " Stub function found\n");
1229 // Create a new stub function.
1230 DEBUG(dbgs() << " Create a new stub function\n");
1232 uintptr_t BaseAddress = uintptr_t(Section.Address);
1233 uintptr_t StubAlignment = getStubAlignment();
1234 StubAddress = (BaseAddress + Section.StubOffset + StubAlignment - 1) &
1236 unsigned StubOffset = StubAddress - BaseAddress;
1238 Stubs[Value] = StubOffset;
1239 createStubFunction((uint8_t *)StubAddress);
1240 RelocationEntry RE(SectionID, StubOffset + 8, ELF::R_390_64,
1242 if (Value.SymbolName)
1243 addRelocationForSymbol(RE, Value.SymbolName);
1245 addRelocationForSection(RE, Value.SectionID);
1246 Section.StubOffset = StubOffset + getMaxStubSize();
1249 if (RelType == ELF::R_390_GOTENT)
1250 resolveRelocation(Section, Offset, StubAddress + 8, ELF::R_390_PC32DBL,
1253 resolveRelocation(Section, Offset, StubAddress, RelType, Addend);
1254 } else if (Arch == Triple::x86_64) {
1255 if (RelType == ELF::R_X86_64_PLT32) {
1256 // The way the PLT relocations normally work is that the linker allocates
1258 // PLT and this relocation makes a PC-relative call into the PLT. The PLT
1259 // entry will then jump to an address provided by the GOT. On first call,
1261 // GOT address will point back into PLT code that resolves the symbol. After
1262 // the first call, the GOT entry points to the actual function.
1264 // For local functions we're ignoring all of that here and just replacing
1265 // the PLT32 relocation type with PC32, which will translate the relocation
1266 // into a PC-relative call directly to the function. For external symbols we
1267 // can't be sure the function will be within 2^32 bytes of the call site, so
1268 // we need to create a stub, which calls into the GOT. This case is
1269 // equivalent to the usual PLT implementation except that we use the stub
1270 // mechanism in RuntimeDyld (which puts stubs at the end of the section)
1271 // rather than allocating a PLT section.
1272 if (Value.SymbolName) {
1273 // This is a call to an external function.
1274 // Look for an existing stub.
1275 SectionEntry &Section = Sections[SectionID];
1276 StubMap::const_iterator i = Stubs.find(Value);
1277 uintptr_t StubAddress;
1278 if (i != Stubs.end()) {
1279 StubAddress = uintptr_t(Section.Address) + i->second;
1280 DEBUG(dbgs() << " Stub function found\n");
1282 // Create a new stub function (equivalent to a PLT entry).
1283 DEBUG(dbgs() << " Create a new stub function\n");
1285 uintptr_t BaseAddress = uintptr_t(Section.Address);
1286 uintptr_t StubAlignment = getStubAlignment();
1287 StubAddress = (BaseAddress + Section.StubOffset + StubAlignment - 1) &
1289 unsigned StubOffset = StubAddress - BaseAddress;
1290 Stubs[Value] = StubOffset;
1291 createStubFunction((uint8_t *)StubAddress);
1293 // Bump our stub offset counter
1294 Section.StubOffset = StubOffset + getMaxStubSize();
1296 // Allocate a GOT Entry
1297 uint64_t GOTOffset = allocateGOTEntries(SectionID, 1);
1299 // The load of the GOT address has an addend of -4
1300 resolveGOTOffsetRelocation(SectionID, StubOffset + 2, GOTOffset - 4);
1302 // Fill in the value of the symbol we're targeting into the GOT
1303 addRelocationForSymbol(computeGOTOffsetRE(SectionID,GOTOffset,0,ELF::R_X86_64_64),
1307 // Make the target call a call into the stub table.
1308 resolveRelocation(Section, Offset, StubAddress, ELF::R_X86_64_PC32,
1311 RelocationEntry RE(SectionID, Offset, ELF::R_X86_64_PC32, Value.Addend,
1313 addRelocationForSection(RE, Value.SectionID);
1315 } else if (RelType == ELF::R_X86_64_GOTPCREL) {
1316 uint64_t GOTOffset = allocateGOTEntries(SectionID, 1);
1317 resolveGOTOffsetRelocation(SectionID, Offset, GOTOffset + Addend);
1319 // Fill in the value of the symbol we're targeting into the GOT
1320 RelocationEntry RE = computeGOTOffsetRE(SectionID, GOTOffset, Value.Offset, ELF::R_X86_64_64);
1321 if (Value.SymbolName)
1322 addRelocationForSymbol(RE, Value.SymbolName);
1324 addRelocationForSection(RE, Value.SectionID);
1325 } else if (RelType == ELF::R_X86_64_PC32) {
1326 Value.Addend += support::ulittle32_t::ref(computePlaceholderAddress(SectionID, Offset));
1327 processSimpleRelocation(SectionID, Offset, RelType, Value);
1328 } else if (RelType == ELF::R_X86_64_PC64) {
1329 Value.Addend += support::ulittle64_t::ref(computePlaceholderAddress(SectionID, Offset));
1330 processSimpleRelocation(SectionID, Offset, RelType, Value);
1332 processSimpleRelocation(SectionID, Offset, RelType, Value);
1335 if (Arch == Triple::x86) {
1336 Value.Addend += support::ulittle32_t::ref(computePlaceholderAddress(SectionID, Offset));
1338 processSimpleRelocation(SectionID, Offset, RelType, Value);
1343 size_t RuntimeDyldELF::getGOTEntrySize() {
1344 // We don't use the GOT in all of these cases, but it's essentially free
1345 // to put them all here.
1348 case Triple::x86_64:
1349 case Triple::aarch64:
1350 case Triple::aarch64_be:
1352 case Triple::ppc64le:
1353 case Triple::systemz:
1354 Result = sizeof(uint64_t);
1360 case Triple::mipsel:
1361 Result = sizeof(uint32_t);
1364 llvm_unreachable("Unsupported CPU type!");
1369 uint64_t RuntimeDyldELF::allocateGOTEntries(unsigned SectionID, unsigned no)
1371 (void)SectionID; // The GOT Section is the same for all section in the object file
1372 if (GOTSectionID == 0) {
1373 GOTSectionID = Sections.size();
1374 // Reserve a section id. We'll allocate the section later
1375 // once we know the total size
1376 Sections.push_back(SectionEntry(".got", 0, 0, 0));
1378 uint64_t StartOffset = CurrentGOTIndex * getGOTEntrySize();
1379 CurrentGOTIndex += no;
1383 void RuntimeDyldELF::resolveGOTOffsetRelocation(unsigned SectionID, uint64_t Offset, uint64_t GOTOffset)
1385 // Fill in the relative address of the GOT Entry into the stub
1386 RelocationEntry GOTRE(SectionID, Offset, ELF::R_X86_64_PC32, GOTOffset);
1387 addRelocationForSection(GOTRE, GOTSectionID);
1390 RelocationEntry RuntimeDyldELF::computeGOTOffsetRE(unsigned SectionID, uint64_t GOTOffset, uint64_t SymbolOffset,
1393 (void)SectionID; // The GOT Section is the same for all section in the object file
1394 return RelocationEntry(GOTSectionID, GOTOffset, Type, SymbolOffset);
1397 void RuntimeDyldELF::finalizeLoad(const ObjectFile &Obj,
1398 ObjSectionToIDMap &SectionMap) {
1399 // If necessary, allocate the global offset table
1400 if (GOTSectionID != 0) {
1401 // Allocate memory for the section
1402 size_t TotalSize = CurrentGOTIndex * getGOTEntrySize();
1403 uint8_t *Addr = MemMgr.allocateDataSection(TotalSize, getGOTEntrySize(),
1404 GOTSectionID, ".got", false);
1406 report_fatal_error("Unable to allocate memory for GOT!");
1408 Sections[GOTSectionID] = SectionEntry(".got", Addr, TotalSize, 0);
1411 Checker->registerSection(Obj.getFileName(), GOTSectionID);
1413 // For now, initialize all GOT entries to zero. We'll fill them in as
1414 // needed when GOT-based relocations are applied.
1415 memset(Addr, 0, TotalSize);
1418 // Look for and record the EH frame section.
1419 ObjSectionToIDMap::iterator i, e;
1420 for (i = SectionMap.begin(), e = SectionMap.end(); i != e; ++i) {
1421 const SectionRef &Section = i->first;
1423 Section.getName(Name);
1424 if (Name == ".eh_frame") {
1425 UnregisteredEHFrameSections.push_back(i->second);
1431 CurrentGOTIndex = 0;
1434 bool RuntimeDyldELF::isCompatibleFile(const object::ObjectFile &Obj) const {