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 #define DEBUG_TYPE "dyld"
15 #include "RuntimeDyldELF.h"
16 #include "JITRegistrar.h"
17 #include "ObjectImageCommon.h"
18 #include "llvm/ADT/IntervalMap.h"
19 #include "llvm/ADT/OwningPtr.h"
20 #include "llvm/ADT/STLExtras.h"
21 #include "llvm/ADT/StringRef.h"
22 #include "llvm/ADT/Triple.h"
23 #include "llvm/ExecutionEngine/ObjectBuffer.h"
24 #include "llvm/ExecutionEngine/ObjectImage.h"
25 #include "llvm/Object/ELF.h"
26 #include "llvm/Object/ObjectFile.h"
27 #include "llvm/Support/ELF.h"
29 using namespace llvm::object;
34 error_code check(error_code Err) {
36 report_fatal_error(Err.message());
43 : public ELFObjectFile<ELFT> {
44 LLVM_ELF_IMPORT_TYPES_ELFT(ELFT)
46 typedef Elf_Shdr_Impl<ELFT> Elf_Shdr;
47 typedef Elf_Sym_Impl<ELFT> Elf_Sym;
49 Elf_Rel_Impl<ELFT, false> Elf_Rel;
51 Elf_Rel_Impl<ELFT, true> Elf_Rela;
53 typedef Elf_Ehdr_Impl<ELFT> Elf_Ehdr;
55 typedef typename ELFDataTypeTypedefHelper<
56 ELFT>::value_type addr_type;
59 DyldELFObject(MemoryBuffer *Wrapper, error_code &ec);
61 void updateSectionAddress(const SectionRef &Sec, uint64_t Addr);
62 void updateSymbolAddress(const SymbolRef &Sym, uint64_t Addr);
64 // Methods for type inquiry through isa, cast and dyn_cast
65 static inline bool classof(const Binary *v) {
66 return (isa<ELFObjectFile<ELFT> >(v)
67 && classof(cast<ELFObjectFile
70 static inline bool classof(
71 const ELFObjectFile<ELFT> *v) {
72 return v->isDyldType();
77 class ELFObjectImage : public ObjectImageCommon {
79 DyldELFObject<ELFT> *DyldObj;
83 ELFObjectImage(ObjectBuffer *Input,
84 DyldELFObject<ELFT> *Obj)
85 : ObjectImageCommon(Input, Obj),
89 virtual ~ELFObjectImage() {
91 deregisterWithDebugger();
94 // Subclasses can override these methods to update the image with loaded
95 // addresses for sections and common symbols
96 virtual void updateSectionAddress(const SectionRef &Sec, uint64_t Addr)
98 DyldObj->updateSectionAddress(Sec, Addr);
101 virtual void updateSymbolAddress(const SymbolRef &Sym, uint64_t Addr)
103 DyldObj->updateSymbolAddress(Sym, Addr);
106 virtual void registerWithDebugger()
108 JITRegistrar::getGDBRegistrar().registerObject(*Buffer);
111 virtual void deregisterWithDebugger()
113 JITRegistrar::getGDBRegistrar().deregisterObject(*Buffer);
117 // The MemoryBuffer passed into this constructor is just a wrapper around the
118 // actual memory. Ultimately, the Binary parent class will take ownership of
119 // this MemoryBuffer object but not the underlying memory.
121 DyldELFObject<ELFT>::DyldELFObject(MemoryBuffer *Wrapper, error_code &ec)
122 : ELFObjectFile<ELFT>(Wrapper, ec) {
123 this->isDyldELFObject = true;
127 void DyldELFObject<ELFT>::updateSectionAddress(const SectionRef &Sec,
129 DataRefImpl ShdrRef = Sec.getRawDataRefImpl();
130 Elf_Shdr *shdr = const_cast<Elf_Shdr*>(
131 reinterpret_cast<const Elf_Shdr *>(ShdrRef.p));
133 // This assumes the address passed in matches the target address bitness
134 // The template-based type cast handles everything else.
135 shdr->sh_addr = static_cast<addr_type>(Addr);
139 void DyldELFObject<ELFT>::updateSymbolAddress(const SymbolRef &SymRef,
142 Elf_Sym *sym = const_cast<Elf_Sym*>(
143 ELFObjectFile<ELFT>::getSymbol(SymRef.getRawDataRefImpl()));
145 // This assumes the address passed in matches the target address bitness
146 // The template-based type cast handles everything else.
147 sym->st_value = static_cast<addr_type>(Addr);
154 ObjectImage *RuntimeDyldELF::createObjectImage(ObjectBuffer *Buffer) {
155 if (Buffer->getBufferSize() < ELF::EI_NIDENT)
156 llvm_unreachable("Unexpected ELF object size");
157 std::pair<unsigned char, unsigned char> Ident = std::make_pair(
158 (uint8_t)Buffer->getBufferStart()[ELF::EI_CLASS],
159 (uint8_t)Buffer->getBufferStart()[ELF::EI_DATA]);
162 if (Ident.first == ELF::ELFCLASS32 && Ident.second == ELF::ELFDATA2LSB) {
163 DyldELFObject<ELFType<support::little, 4, false> > *Obj =
164 new DyldELFObject<ELFType<support::little, 4, false> >(
165 Buffer->getMemBuffer(), ec);
166 return new ELFObjectImage<ELFType<support::little, 4, false> >(Buffer, Obj);
168 else if (Ident.first == ELF::ELFCLASS32 && Ident.second == ELF::ELFDATA2MSB) {
169 DyldELFObject<ELFType<support::big, 4, false> > *Obj =
170 new DyldELFObject<ELFType<support::big, 4, false> >(
171 Buffer->getMemBuffer(), ec);
172 return new ELFObjectImage<ELFType<support::big, 4, false> >(Buffer, Obj);
174 else if (Ident.first == ELF::ELFCLASS64 && Ident.second == ELF::ELFDATA2MSB) {
175 DyldELFObject<ELFType<support::big, 8, true> > *Obj =
176 new DyldELFObject<ELFType<support::big, 8, true> >(
177 Buffer->getMemBuffer(), ec);
178 return new ELFObjectImage<ELFType<support::big, 8, true> >(Buffer, Obj);
180 else if (Ident.first == ELF::ELFCLASS64 && Ident.second == ELF::ELFDATA2LSB) {
181 DyldELFObject<ELFType<support::little, 8, true> > *Obj =
182 new DyldELFObject<ELFType<support::little, 8, true> >(
183 Buffer->getMemBuffer(), ec);
184 return new ELFObjectImage<ELFType<support::little, 8, true> >(Buffer, Obj);
187 llvm_unreachable("Unexpected ELF format");
190 RuntimeDyldELF::~RuntimeDyldELF() {
193 void RuntimeDyldELF::resolveX86_64Relocation(const SectionEntry &Section,
200 llvm_unreachable("Relocation type not implemented yet!");
202 case ELF::R_X86_64_64: {
203 uint64_t *Target = reinterpret_cast<uint64_t*>(Section.Address + Offset);
204 *Target = Value + Addend;
205 DEBUG(dbgs() << "Writing " << format("%p", (Value + Addend))
206 << " at " << format("%p\n",Target));
209 case ELF::R_X86_64_32:
210 case ELF::R_X86_64_32S: {
212 assert((Type == ELF::R_X86_64_32 && (Value <= UINT32_MAX)) ||
213 (Type == ELF::R_X86_64_32S &&
214 ((int64_t)Value <= INT32_MAX && (int64_t)Value >= INT32_MIN)));
215 uint32_t TruncatedAddr = (Value & 0xFFFFFFFF);
216 uint32_t *Target = reinterpret_cast<uint32_t*>(Section.Address + Offset);
217 *Target = TruncatedAddr;
218 DEBUG(dbgs() << "Writing " << format("%p", TruncatedAddr)
219 << " at " << format("%p\n",Target));
222 case ELF::R_X86_64_PC32: {
223 // Get the placeholder value from the generated object since
224 // a previous relocation attempt may have overwritten the loaded version
225 uint32_t *Placeholder = reinterpret_cast<uint32_t*>(Section.ObjAddress
227 uint32_t *Target = reinterpret_cast<uint32_t*>(Section.Address + Offset);
228 uint64_t FinalAddress = Section.LoadAddress + Offset;
229 int64_t RealOffset = *Placeholder + Value + Addend - FinalAddress;
230 assert(RealOffset <= INT32_MAX && RealOffset >= INT32_MIN);
231 int32_t TruncOffset = (RealOffset & 0xFFFFFFFF);
232 *Target = TruncOffset;
238 void RuntimeDyldELF::resolveX86Relocation(const SectionEntry &Section,
244 case ELF::R_386_32: {
245 // Get the placeholder value from the generated object since
246 // a previous relocation attempt may have overwritten the loaded version
247 uint32_t *Placeholder = reinterpret_cast<uint32_t*>(Section.ObjAddress
249 uint32_t *Target = reinterpret_cast<uint32_t*>(Section.Address + Offset);
250 *Target = *Placeholder + Value + Addend;
253 case ELF::R_386_PC32: {
254 // Get the placeholder value from the generated object since
255 // a previous relocation attempt may have overwritten the loaded version
256 uint32_t *Placeholder = reinterpret_cast<uint32_t*>(Section.ObjAddress
258 uint32_t *Target = reinterpret_cast<uint32_t*>(Section.Address + Offset);
259 uint32_t FinalAddress = ((Section.LoadAddress + Offset) & 0xFFFFFFFF);
260 uint32_t RealOffset = *Placeholder + Value + Addend - FinalAddress;
261 *Target = RealOffset;
265 // There are other relocation types, but it appears these are the
266 // only ones currently used by the LLVM ELF object writer
267 llvm_unreachable("Relocation type not implemented yet!");
272 void RuntimeDyldELF::resolveAArch64Relocation(const SectionEntry &Section,
277 uint32_t *TargetPtr = reinterpret_cast<uint32_t*>(Section.Address + Offset);
278 uint64_t FinalAddress = Section.LoadAddress + Offset;
280 DEBUG(dbgs() << "resolveAArch64Relocation, LocalAddress: 0x"
281 << format("%llx", Section.Address + Offset)
282 << " FinalAddress: 0x" << format("%llx",FinalAddress)
283 << " Value: 0x" << format("%llx",Value)
284 << " Type: 0x" << format("%x",Type)
285 << " Addend: 0x" << format("%llx",Addend)
290 llvm_unreachable("Relocation type not implemented yet!");
292 case ELF::R_AARCH64_PREL32: { // test-shift.ll (.eh_frame)
293 uint64_t Result = Value + Addend - FinalAddress;
294 assert(static_cast<int64_t>(Result) >= INT32_MIN &&
295 static_cast<int64_t>(Result) <= UINT32_MAX);
296 *TargetPtr = static_cast<uint32_t>(Result & 0xffffffffU);
299 case ELF::R_AARCH64_CALL26: // fallthrough
300 case ELF::R_AARCH64_JUMP26: {
301 // Operation: S+A-P. Set Call or B immediate value to bits fff_fffc of the
303 uint64_t BranchImm = Value + Addend - FinalAddress;
305 // "Check that -2^27 <= result < 2^27".
306 assert(-(1LL << 27) <= static_cast<int64_t>(BranchImm) &&
307 static_cast<int64_t>(BranchImm) < (1LL << 27));
308 // Immediate goes in bits 25:0 of B and BL.
309 *TargetPtr |= static_cast<uint32_t>(BranchImm & 0xffffffcU) >> 2;
312 case ELF::R_AARCH64_MOVW_UABS_G3: {
313 uint64_t Result = Value + Addend;
314 // Immediate goes in bits 20:5 of MOVZ/MOVK instruction
315 *TargetPtr |= Result >> (48 - 5);
316 // Shift is "lsl #48", in bits 22:21
317 *TargetPtr |= 3 << 21;
320 case ELF::R_AARCH64_MOVW_UABS_G2_NC: {
321 uint64_t Result = Value + Addend;
322 // Immediate goes in bits 20:5 of MOVZ/MOVK instruction
323 *TargetPtr |= ((Result & 0xffff00000000ULL) >> (32 - 5));
324 // Shift is "lsl #32", in bits 22:21
325 *TargetPtr |= 2 << 21;
328 case ELF::R_AARCH64_MOVW_UABS_G1_NC: {
329 uint64_t Result = Value + Addend;
330 // Immediate goes in bits 20:5 of MOVZ/MOVK instruction
331 *TargetPtr |= ((Result & 0xffff0000U) >> (16 - 5));
332 // Shift is "lsl #16", in bits 22:21
333 *TargetPtr |= 1 << 21;
336 case ELF::R_AARCH64_MOVW_UABS_G0_NC: {
337 uint64_t Result = Value + Addend;
338 // Immediate goes in bits 20:5 of MOVZ/MOVK instruction
339 *TargetPtr |= ((Result & 0xffffU) << 5);
340 // Shift is "lsl #0", in bits 22:21. No action needed.
346 void RuntimeDyldELF::resolveARMRelocation(const SectionEntry &Section,
351 // TODO: Add Thumb relocations.
352 uint32_t* TargetPtr = (uint32_t*)(Section.Address + Offset);
353 uint32_t FinalAddress = ((Section.LoadAddress + Offset) & 0xFFFFFFFF);
356 DEBUG(dbgs() << "resolveARMRelocation, LocalAddress: "
357 << Section.Address + Offset
358 << " FinalAddress: " << format("%p",FinalAddress)
359 << " Value: " << format("%x",Value)
360 << " Type: " << format("%x",Type)
361 << " Addend: " << format("%x",Addend)
366 llvm_unreachable("Not implemented relocation type!");
368 // Write a 32bit value to relocation address, taking into account the
369 // implicit addend encoded in the target.
370 case ELF::R_ARM_TARGET1 :
371 case ELF::R_ARM_ABS32 :
375 // Write first 16 bit of 32 bit value to the mov instruction.
376 // Last 4 bit should be shifted.
377 case ELF::R_ARM_MOVW_ABS_NC :
378 // We are not expecting any other addend in the relocation address.
379 // Using 0x000F0FFF because MOVW has its 16 bit immediate split into 2
380 // non-contiguous fields.
381 assert((*TargetPtr & 0x000F0FFF) == 0);
382 Value = Value & 0xFFFF;
383 *TargetPtr |= Value & 0xFFF;
384 *TargetPtr |= ((Value >> 12) & 0xF) << 16;
387 // Write last 16 bit of 32 bit value to the mov instruction.
388 // Last 4 bit should be shifted.
389 case ELF::R_ARM_MOVT_ABS :
390 // We are not expecting any other addend in the relocation address.
391 // Use 0x000F0FFF for the same reason as R_ARM_MOVW_ABS_NC.
392 assert((*TargetPtr & 0x000F0FFF) == 0);
393 Value = (Value >> 16) & 0xFFFF;
394 *TargetPtr |= Value & 0xFFF;
395 *TargetPtr |= ((Value >> 12) & 0xF) << 16;
398 // Write 24 bit relative value to the branch instruction.
399 case ELF::R_ARM_PC24 : // Fall through.
400 case ELF::R_ARM_CALL : // Fall through.
401 case ELF::R_ARM_JUMP24 :
402 int32_t RelValue = static_cast<int32_t>(Value - FinalAddress - 8);
403 RelValue = (RelValue & 0x03FFFFFC) >> 2;
404 *TargetPtr &= 0xFF000000;
405 *TargetPtr |= RelValue;
410 void RuntimeDyldELF::resolveMIPSRelocation(const SectionEntry &Section,
415 uint32_t* TargetPtr = (uint32_t*)(Section.Address + Offset);
418 DEBUG(dbgs() << "resolveMipselocation, LocalAddress: "
419 << Section.Address + Offset
421 << format("%p",Section.LoadAddress + Offset)
422 << " Value: " << format("%x",Value)
423 << " Type: " << format("%x",Type)
424 << " Addend: " << format("%x",Addend)
429 llvm_unreachable("Not implemented relocation type!");
432 *TargetPtr = Value + (*TargetPtr);
435 *TargetPtr = ((*TargetPtr) & 0xfc000000) | (( Value & 0x0fffffff) >> 2);
437 case ELF::R_MIPS_HI16:
438 // Get the higher 16-bits. Also add 1 if bit 15 is 1.
439 Value += ((*TargetPtr) & 0x0000ffff) << 16;
440 *TargetPtr = ((*TargetPtr) & 0xffff0000) |
441 (((Value + 0x8000) >> 16) & 0xffff);
443 case ELF::R_MIPS_LO16:
444 Value += ((*TargetPtr) & 0x0000ffff);
445 *TargetPtr = ((*TargetPtr) & 0xffff0000) | (Value & 0xffff);
450 // Return the .TOC. section address to R_PPC64_TOC relocations.
451 uint64_t RuntimeDyldELF::findPPC64TOC() const {
452 // The TOC consists of sections .got, .toc, .tocbss, .plt in that
453 // order. The TOC starts where the first of these sections starts.
454 SectionList::const_iterator it = Sections.begin();
455 SectionList::const_iterator ite = Sections.end();
456 for (; it != ite; ++it) {
457 if (it->Name == ".got" ||
458 it->Name == ".toc" ||
459 it->Name == ".tocbss" ||
464 // This may happen for
465 // * references to TOC base base (sym@toc, .odp relocation) without
467 // In this case just use the first section (which is usually
468 // the .odp) since the code won't reference the .toc base
470 it = Sections.begin();
473 // Per the ppc64-elf-linux ABI, The TOC base is TOC value plus 0x8000
474 // thus permitting a full 64 Kbytes segment.
475 return it->LoadAddress + 0x8000;
478 // Returns the sections and offset associated with the ODP entry referenced
480 void RuntimeDyldELF::findOPDEntrySection(ObjectImage &Obj,
481 ObjSectionToIDMap &LocalSections,
482 RelocationValueRef &Rel) {
483 // Get the ELF symbol value (st_value) to compare with Relocation offset in
487 for (section_iterator si = Obj.begin_sections(),
488 se = Obj.end_sections(); si != se; si.increment(err)) {
489 StringRef SectionName;
490 check(si->getName(SectionName));
491 if (SectionName != ".opd")
494 for (relocation_iterator i = si->begin_relocations(),
495 e = si->end_relocations(); i != e;) {
498 // The R_PPC64_ADDR64 relocation indicates the first field
501 check(i->getType(TypeFunc));
502 if (TypeFunc != ELF::R_PPC64_ADDR64) {
507 SymbolRef TargetSymbol;
508 uint64_t TargetSymbolOffset;
509 int64_t TargetAdditionalInfo;
510 check(i->getSymbol(TargetSymbol));
511 check(i->getOffset(TargetSymbolOffset));
512 check(i->getAdditionalInfo(TargetAdditionalInfo));
514 i = i.increment(err);
519 // Just check if following relocation is a R_PPC64_TOC
521 check(i->getType(TypeTOC));
522 if (TypeTOC != ELF::R_PPC64_TOC)
525 // Finally compares the Symbol value and the target symbol offset
526 // to check if this .opd entry refers to the symbol the relocation
528 if (Rel.Addend != (intptr_t)TargetSymbolOffset)
531 section_iterator tsi(Obj.end_sections());
532 check(TargetSymbol.getSection(tsi));
533 Rel.SectionID = findOrEmitSection(Obj, (*tsi), true, LocalSections);
534 Rel.Addend = (intptr_t)TargetAdditionalInfo;
538 llvm_unreachable("Attempting to get address of ODP entry!");
541 // Relocation masks following the #lo(value), #hi(value), #higher(value),
542 // and #highest(value) macros defined in section 4.5.1. Relocation Types
543 // in PPC-elf64abi document.
546 uint16_t applyPPClo (uint64_t value)
548 return value & 0xffff;
552 uint16_t applyPPChi (uint64_t value)
554 return (value >> 16) & 0xffff;
558 uint16_t applyPPChigher (uint64_t value)
560 return (value >> 32) & 0xffff;
564 uint16_t applyPPChighest (uint64_t value)
566 return (value >> 48) & 0xffff;
569 void RuntimeDyldELF::resolvePPC64Relocation(const SectionEntry &Section,
574 uint8_t* LocalAddress = Section.Address + Offset;
577 llvm_unreachable("Relocation type not implemented yet!");
579 case ELF::R_PPC64_ADDR16_LO :
580 writeInt16BE(LocalAddress, applyPPClo (Value + Addend));
582 case ELF::R_PPC64_ADDR16_HI :
583 writeInt16BE(LocalAddress, applyPPChi (Value + Addend));
585 case ELF::R_PPC64_ADDR16_HIGHER :
586 writeInt16BE(LocalAddress, applyPPChigher (Value + Addend));
588 case ELF::R_PPC64_ADDR16_HIGHEST :
589 writeInt16BE(LocalAddress, applyPPChighest (Value + Addend));
591 case ELF::R_PPC64_ADDR14 : {
592 assert(((Value + Addend) & 3) == 0);
593 // Preserve the AA/LK bits in the branch instruction
594 uint8_t aalk = *(LocalAddress+3);
595 writeInt16BE(LocalAddress + 2, (aalk & 3) | ((Value + Addend) & 0xfffc));
597 case ELF::R_PPC64_ADDR32 : {
598 int32_t Result = static_cast<int32_t>(Value + Addend);
599 if (SignExtend32<32>(Result) != Result)
600 llvm_unreachable("Relocation R_PPC64_ADDR32 overflow");
601 writeInt32BE(LocalAddress, Result);
603 case ELF::R_PPC64_REL24 : {
604 uint64_t FinalAddress = (Section.LoadAddress + Offset);
605 int32_t delta = static_cast<int32_t>(Value - FinalAddress + Addend);
606 if (SignExtend32<24>(delta) != delta)
607 llvm_unreachable("Relocation R_PPC64_REL24 overflow");
608 // Generates a 'bl <address>' instruction
609 writeInt32BE(LocalAddress, 0x48000001 | (delta & 0x03FFFFFC));
611 case ELF::R_PPC64_REL32 : {
612 uint64_t FinalAddress = (Section.LoadAddress + Offset);
613 int32_t delta = static_cast<int32_t>(Value - FinalAddress + Addend);
614 if (SignExtend32<32>(delta) != delta)
615 llvm_unreachable("Relocation R_PPC64_REL32 overflow");
616 writeInt32BE(LocalAddress, delta);
618 case ELF::R_PPC64_ADDR64 :
619 writeInt64BE(LocalAddress, Value + Addend);
621 case ELF::R_PPC64_TOC :
622 writeInt64BE(LocalAddress, findPPC64TOC());
624 case ELF::R_PPC64_TOC16 : {
625 uint64_t TOCStart = findPPC64TOC();
626 Value = applyPPClo((Value + Addend) - TOCStart);
627 writeInt16BE(LocalAddress, applyPPClo(Value));
629 case ELF::R_PPC64_TOC16_DS : {
630 uint64_t TOCStart = findPPC64TOC();
631 Value = ((Value + Addend) - TOCStart);
632 writeInt16BE(LocalAddress, applyPPClo(Value));
637 void RuntimeDyldELF::resolveSystemZRelocation(const SectionEntry &Section,
642 uint8_t *LocalAddress = Section.Address + Offset;
645 llvm_unreachable("Relocation type not implemented yet!");
647 case ELF::R_390_PC16DBL:
648 case ELF::R_390_PLT16DBL: {
649 int64_t Delta = (Value + Addend) - (Section.LoadAddress + Offset);
650 assert(int16_t(Delta / 2) * 2 == Delta && "R_390_PC16DBL overflow");
651 writeInt16BE(LocalAddress, Delta / 2);
654 case ELF::R_390_PC32DBL:
655 case ELF::R_390_PLT32DBL: {
656 int64_t Delta = (Value + Addend) - (Section.LoadAddress + Offset);
657 assert(int32_t(Delta / 2) * 2 == Delta && "R_390_PC32DBL overflow");
658 writeInt32BE(LocalAddress, Delta / 2);
661 case ELF::R_390_PC32: {
662 int64_t Delta = (Value + Addend) - (Section.LoadAddress + Offset);
663 assert(int32_t(Delta) == Delta && "R_390_PC32 overflow");
664 writeInt32BE(LocalAddress, Delta);
668 writeInt64BE(LocalAddress, Value + Addend);
673 void RuntimeDyldELF::resolveRelocation(const RelocationEntry &RE,
675 const SectionEntry &Section = Sections[RE.SectionID];
676 return resolveRelocation(Section, RE.Offset, Value, RE.RelType, RE.Addend);
679 void RuntimeDyldELF::resolveRelocation(const SectionEntry &Section,
686 resolveX86_64Relocation(Section, Offset, Value, Type, Addend);
689 resolveX86Relocation(Section, Offset,
690 (uint32_t)(Value & 0xffffffffL), Type,
691 (uint32_t)(Addend & 0xffffffffL));
693 case Triple::aarch64:
694 resolveAArch64Relocation(Section, Offset, Value, Type, Addend);
696 case Triple::arm: // Fall through.
698 resolveARMRelocation(Section, Offset,
699 (uint32_t)(Value & 0xffffffffL), Type,
700 (uint32_t)(Addend & 0xffffffffL));
702 case Triple::mips: // Fall through.
704 resolveMIPSRelocation(Section, Offset,
705 (uint32_t)(Value & 0xffffffffL), Type,
706 (uint32_t)(Addend & 0xffffffffL));
709 resolvePPC64Relocation(Section, Offset, Value, Type, Addend);
711 case Triple::systemz:
712 resolveSystemZRelocation(Section, Offset, Value, Type, Addend);
714 default: llvm_unreachable("Unsupported CPU type!");
718 void RuntimeDyldELF::processRelocationRef(unsigned SectionID,
721 ObjSectionToIDMap &ObjSectionToID,
722 const SymbolTableMap &Symbols,
725 Check(RelI.getType(RelType));
727 Check(RelI.getAdditionalInfo(Addend));
729 Check(RelI.getSymbol(Symbol));
731 // Obtain the symbol name which is referenced in the relocation
732 StringRef TargetName;
733 Symbol.getName(TargetName);
734 DEBUG(dbgs() << "\t\tRelType: " << RelType
735 << " Addend: " << Addend
736 << " TargetName: " << TargetName
738 RelocationValueRef Value;
739 // First search for the symbol in the local symbol table
740 SymbolTableMap::const_iterator lsi = Symbols.find(TargetName.data());
741 SymbolRef::Type SymType;
742 Symbol.getType(SymType);
743 if (lsi != Symbols.end()) {
744 Value.SectionID = lsi->second.first;
745 Value.Addend = lsi->second.second + Addend;
747 // Search for the symbol in the global symbol table
748 SymbolTableMap::const_iterator gsi =
749 GlobalSymbolTable.find(TargetName.data());
750 if (gsi != GlobalSymbolTable.end()) {
751 Value.SectionID = gsi->second.first;
752 Value.Addend = gsi->second.second + Addend;
755 case SymbolRef::ST_Debug: {
756 // TODO: Now ELF SymbolRef::ST_Debug = STT_SECTION, it's not obviously
757 // and can be changed by another developers. Maybe best way is add
758 // a new symbol type ST_Section to SymbolRef and use it.
759 section_iterator si(Obj.end_sections());
760 Symbol.getSection(si);
761 if (si == Obj.end_sections())
762 llvm_unreachable("Symbol section not found, bad object file format!");
763 DEBUG(dbgs() << "\t\tThis is section symbol\n");
764 // Default to 'true' in case isText fails (though it never does).
767 Value.SectionID = findOrEmitSection(Obj,
771 Value.Addend = Addend;
774 case SymbolRef::ST_Unknown: {
775 Value.SymbolName = TargetName.data();
776 Value.Addend = Addend;
780 llvm_unreachable("Unresolved symbol type!");
786 Check(RelI.getOffset(Offset));
788 DEBUG(dbgs() << "\t\tSectionID: " << SectionID
789 << " Offset: " << Offset
791 if (Arch == Triple::aarch64 &&
792 (RelType == ELF::R_AARCH64_CALL26 ||
793 RelType == ELF::R_AARCH64_JUMP26)) {
794 // This is an AArch64 branch relocation, need to use a stub function.
795 DEBUG(dbgs() << "\t\tThis is an AArch64 branch relocation.");
796 SectionEntry &Section = Sections[SectionID];
798 // Look for an existing stub.
799 StubMap::const_iterator i = Stubs.find(Value);
800 if (i != Stubs.end()) {
801 resolveRelocation(Section, Offset,
802 (uint64_t)Section.Address + i->second, RelType, 0);
803 DEBUG(dbgs() << " Stub function found\n");
805 // Create a new stub function.
806 DEBUG(dbgs() << " Create a new stub function\n");
807 Stubs[Value] = Section.StubOffset;
808 uint8_t *StubTargetAddr = createStubFunction(Section.Address +
811 RelocationEntry REmovz_g3(SectionID,
812 StubTargetAddr - Section.Address,
813 ELF::R_AARCH64_MOVW_UABS_G3, Value.Addend);
814 RelocationEntry REmovk_g2(SectionID,
815 StubTargetAddr - Section.Address + 4,
816 ELF::R_AARCH64_MOVW_UABS_G2_NC, Value.Addend);
817 RelocationEntry REmovk_g1(SectionID,
818 StubTargetAddr - Section.Address + 8,
819 ELF::R_AARCH64_MOVW_UABS_G1_NC, Value.Addend);
820 RelocationEntry REmovk_g0(SectionID,
821 StubTargetAddr - Section.Address + 12,
822 ELF::R_AARCH64_MOVW_UABS_G0_NC, Value.Addend);
824 if (Value.SymbolName) {
825 addRelocationForSymbol(REmovz_g3, Value.SymbolName);
826 addRelocationForSymbol(REmovk_g2, Value.SymbolName);
827 addRelocationForSymbol(REmovk_g1, Value.SymbolName);
828 addRelocationForSymbol(REmovk_g0, Value.SymbolName);
830 addRelocationForSection(REmovz_g3, Value.SectionID);
831 addRelocationForSection(REmovk_g2, Value.SectionID);
832 addRelocationForSection(REmovk_g1, Value.SectionID);
833 addRelocationForSection(REmovk_g0, Value.SectionID);
835 resolveRelocation(Section, Offset,
836 (uint64_t)Section.Address + Section.StubOffset,
838 Section.StubOffset += getMaxStubSize();
840 } else if (Arch == Triple::arm &&
841 (RelType == ELF::R_ARM_PC24 ||
842 RelType == ELF::R_ARM_CALL ||
843 RelType == ELF::R_ARM_JUMP24)) {
844 // This is an ARM branch relocation, need to use a stub function.
845 DEBUG(dbgs() << "\t\tThis is an ARM branch relocation.");
846 SectionEntry &Section = Sections[SectionID];
848 // Look for an existing stub.
849 StubMap::const_iterator i = Stubs.find(Value);
850 if (i != Stubs.end()) {
851 resolveRelocation(Section, Offset,
852 (uint64_t)Section.Address + i->second, RelType, 0);
853 DEBUG(dbgs() << " Stub function found\n");
855 // Create a new stub function.
856 DEBUG(dbgs() << " Create a new stub function\n");
857 Stubs[Value] = Section.StubOffset;
858 uint8_t *StubTargetAddr = createStubFunction(Section.Address +
860 RelocationEntry RE(SectionID, StubTargetAddr - Section.Address,
861 ELF::R_ARM_ABS32, Value.Addend);
862 if (Value.SymbolName)
863 addRelocationForSymbol(RE, Value.SymbolName);
865 addRelocationForSection(RE, Value.SectionID);
867 resolveRelocation(Section, Offset,
868 (uint64_t)Section.Address + Section.StubOffset,
870 Section.StubOffset += getMaxStubSize();
872 } else if ((Arch == Triple::mipsel || Arch == Triple::mips) &&
873 RelType == ELF::R_MIPS_26) {
874 // This is an Mips branch relocation, need to use a stub function.
875 DEBUG(dbgs() << "\t\tThis is a Mips branch relocation.");
876 SectionEntry &Section = Sections[SectionID];
877 uint8_t *Target = Section.Address + Offset;
878 uint32_t *TargetAddress = (uint32_t *)Target;
880 // Extract the addend from the instruction.
881 uint32_t Addend = ((*TargetAddress) & 0x03ffffff) << 2;
883 Value.Addend += Addend;
885 // Look up for existing stub.
886 StubMap::const_iterator i = Stubs.find(Value);
887 if (i != Stubs.end()) {
888 resolveRelocation(Section, Offset,
889 (uint64_t)Section.Address + i->second, RelType, 0);
890 DEBUG(dbgs() << " Stub function found\n");
892 // Create a new stub function.
893 DEBUG(dbgs() << " Create a new stub function\n");
894 Stubs[Value] = Section.StubOffset;
895 uint8_t *StubTargetAddr = createStubFunction(Section.Address +
898 // Creating Hi and Lo relocations for the filled stub instructions.
899 RelocationEntry REHi(SectionID,
900 StubTargetAddr - Section.Address,
901 ELF::R_MIPS_HI16, Value.Addend);
902 RelocationEntry RELo(SectionID,
903 StubTargetAddr - Section.Address + 4,
904 ELF::R_MIPS_LO16, Value.Addend);
906 if (Value.SymbolName) {
907 addRelocationForSymbol(REHi, Value.SymbolName);
908 addRelocationForSymbol(RELo, Value.SymbolName);
910 addRelocationForSection(REHi, Value.SectionID);
911 addRelocationForSection(RELo, Value.SectionID);
914 resolveRelocation(Section, Offset,
915 (uint64_t)Section.Address + Section.StubOffset,
917 Section.StubOffset += getMaxStubSize();
919 } else if (Arch == Triple::ppc64) {
920 if (RelType == ELF::R_PPC64_REL24) {
921 // A PPC branch relocation will need a stub function if the target is
922 // an external symbol (Symbol::ST_Unknown) or if the target address
923 // is not within the signed 24-bits branch address.
924 SectionEntry &Section = Sections[SectionID];
925 uint8_t *Target = Section.Address + Offset;
926 bool RangeOverflow = false;
927 if (SymType != SymbolRef::ST_Unknown) {
928 // A function call may points to the .opd entry, so the final symbol value
929 // in calculated based in the relocation values in .opd section.
930 findOPDEntrySection(Obj, ObjSectionToID, Value);
931 uint8_t *RelocTarget = Sections[Value.SectionID].Address + Value.Addend;
932 int32_t delta = static_cast<int32_t>(Target - RelocTarget);
933 // If it is within 24-bits branch range, just set the branch target
934 if (SignExtend32<24>(delta) == delta) {
935 RelocationEntry RE(SectionID, Offset, RelType, Value.Addend);
936 if (Value.SymbolName)
937 addRelocationForSymbol(RE, Value.SymbolName);
939 addRelocationForSection(RE, Value.SectionID);
941 RangeOverflow = true;
944 if (SymType == SymbolRef::ST_Unknown || RangeOverflow == true) {
945 // It is an external symbol (SymbolRef::ST_Unknown) or within a range
946 // larger than 24-bits.
947 StubMap::const_iterator i = Stubs.find(Value);
948 if (i != Stubs.end()) {
949 // Symbol function stub already created, just relocate to it
950 resolveRelocation(Section, Offset,
951 (uint64_t)Section.Address + i->second, RelType, 0);
952 DEBUG(dbgs() << " Stub function found\n");
954 // Create a new stub function.
955 DEBUG(dbgs() << " Create a new stub function\n");
956 Stubs[Value] = Section.StubOffset;
957 uint8_t *StubTargetAddr = createStubFunction(Section.Address +
959 RelocationEntry RE(SectionID, StubTargetAddr - Section.Address,
960 ELF::R_PPC64_ADDR64, Value.Addend);
962 // Generates the 64-bits address loads as exemplified in section
963 // 4.5.1 in PPC64 ELF ABI.
964 RelocationEntry REhst(SectionID,
965 StubTargetAddr - Section.Address + 2,
966 ELF::R_PPC64_ADDR16_HIGHEST, Value.Addend);
967 RelocationEntry REhr(SectionID,
968 StubTargetAddr - Section.Address + 6,
969 ELF::R_PPC64_ADDR16_HIGHER, Value.Addend);
970 RelocationEntry REh(SectionID,
971 StubTargetAddr - Section.Address + 14,
972 ELF::R_PPC64_ADDR16_HI, Value.Addend);
973 RelocationEntry REl(SectionID,
974 StubTargetAddr - Section.Address + 18,
975 ELF::R_PPC64_ADDR16_LO, Value.Addend);
977 if (Value.SymbolName) {
978 addRelocationForSymbol(REhst, Value.SymbolName);
979 addRelocationForSymbol(REhr, Value.SymbolName);
980 addRelocationForSymbol(REh, Value.SymbolName);
981 addRelocationForSymbol(REl, Value.SymbolName);
983 addRelocationForSection(REhst, Value.SectionID);
984 addRelocationForSection(REhr, Value.SectionID);
985 addRelocationForSection(REh, Value.SectionID);
986 addRelocationForSection(REl, Value.SectionID);
989 resolveRelocation(Section, Offset,
990 (uint64_t)Section.Address + Section.StubOffset,
992 if (SymType == SymbolRef::ST_Unknown)
993 // Restore the TOC for external calls
994 writeInt32BE(Target+4, 0xE8410028); // ld r2,40(r1)
995 Section.StubOffset += getMaxStubSize();
999 RelocationEntry RE(SectionID, Offset, RelType, Value.Addend);
1000 // Extra check to avoid relocation againt empty symbols (usually
1001 // the R_PPC64_TOC).
1002 if (Value.SymbolName && !TargetName.empty())
1003 addRelocationForSymbol(RE, Value.SymbolName);
1005 addRelocationForSection(RE, Value.SectionID);
1007 } else if (Arch == Triple::systemz &&
1008 (RelType == ELF::R_390_PLT32DBL ||
1009 RelType == ELF::R_390_GOTENT)) {
1010 // Create function stubs for both PLT and GOT references, regardless of
1011 // whether the GOT reference is to data or code. The stub contains the
1012 // full address of the symbol, as needed by GOT references, and the
1013 // executable part only adds an overhead of 8 bytes.
1015 // We could try to conserve space by allocating the code and data
1016 // parts of the stub separately. However, as things stand, we allocate
1017 // a stub for every relocation, so using a GOT in JIT code should be
1018 // no less space efficient than using an explicit constant pool.
1019 DEBUG(dbgs() << "\t\tThis is a SystemZ indirect relocation.");
1020 SectionEntry &Section = Sections[SectionID];
1022 // Look for an existing stub.
1023 StubMap::const_iterator i = Stubs.find(Value);
1024 uintptr_t StubAddress;
1025 if (i != Stubs.end()) {
1026 StubAddress = uintptr_t(Section.Address) + i->second;
1027 DEBUG(dbgs() << " Stub function found\n");
1029 // Create a new stub function.
1030 DEBUG(dbgs() << " Create a new stub function\n");
1032 uintptr_t BaseAddress = uintptr_t(Section.Address);
1033 uintptr_t StubAlignment = getStubAlignment();
1034 StubAddress = (BaseAddress + Section.StubOffset +
1035 StubAlignment - 1) & -StubAlignment;
1036 unsigned StubOffset = StubAddress - BaseAddress;
1038 Stubs[Value] = StubOffset;
1039 createStubFunction((uint8_t *)StubAddress);
1040 RelocationEntry RE(SectionID, StubOffset + 8,
1041 ELF::R_390_64, Value.Addend - Addend);
1042 if (Value.SymbolName)
1043 addRelocationForSymbol(RE, Value.SymbolName);
1045 addRelocationForSection(RE, Value.SectionID);
1046 Section.StubOffset = StubOffset + getMaxStubSize();
1049 if (RelType == ELF::R_390_GOTENT)
1050 resolveRelocation(Section, Offset, StubAddress + 8,
1051 ELF::R_390_PC32DBL, Addend);
1053 resolveRelocation(Section, Offset, StubAddress, RelType, Addend);
1055 RelocationEntry RE(SectionID, Offset, RelType, Value.Addend);
1056 if (Value.SymbolName)
1057 addRelocationForSymbol(RE, Value.SymbolName);
1059 addRelocationForSection(RE, Value.SectionID);
1063 bool RuntimeDyldELF::isCompatibleFormat(const ObjectBuffer *Buffer) const {
1064 if (Buffer->getBufferSize() < strlen(ELF::ElfMagic))
1066 return (memcmp(Buffer->getBufferStart(), ELF::ElfMagic, strlen(ELF::ElfMagic))) == 0;