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 StringRef RuntimeDyldELF::getEHFrameSection() {
155 for (int i = 0, e = Sections.size(); i != e; ++i) {
156 if (Sections[i].Name == ".eh_frame")
157 return StringRef((const char*)Sections[i].Address, Sections[i].Size);
162 ObjectImage *RuntimeDyldELF::createObjectImage(ObjectBuffer *Buffer) {
163 if (Buffer->getBufferSize() < ELF::EI_NIDENT)
164 llvm_unreachable("Unexpected ELF object size");
165 std::pair<unsigned char, unsigned char> Ident = std::make_pair(
166 (uint8_t)Buffer->getBufferStart()[ELF::EI_CLASS],
167 (uint8_t)Buffer->getBufferStart()[ELF::EI_DATA]);
170 if (Ident.first == ELF::ELFCLASS32 && Ident.second == ELF::ELFDATA2LSB) {
171 DyldELFObject<ELFType<support::little, 4, false> > *Obj =
172 new DyldELFObject<ELFType<support::little, 4, false> >(
173 Buffer->getMemBuffer(), ec);
174 return new ELFObjectImage<ELFType<support::little, 4, false> >(Buffer, Obj);
176 else if (Ident.first == ELF::ELFCLASS32 && Ident.second == ELF::ELFDATA2MSB) {
177 DyldELFObject<ELFType<support::big, 4, false> > *Obj =
178 new DyldELFObject<ELFType<support::big, 4, false> >(
179 Buffer->getMemBuffer(), ec);
180 return new ELFObjectImage<ELFType<support::big, 4, false> >(Buffer, Obj);
182 else if (Ident.first == ELF::ELFCLASS64 && Ident.second == ELF::ELFDATA2MSB) {
183 DyldELFObject<ELFType<support::big, 8, true> > *Obj =
184 new DyldELFObject<ELFType<support::big, 8, true> >(
185 Buffer->getMemBuffer(), ec);
186 return new ELFObjectImage<ELFType<support::big, 8, true> >(Buffer, Obj);
188 else if (Ident.first == ELF::ELFCLASS64 && Ident.second == ELF::ELFDATA2LSB) {
189 DyldELFObject<ELFType<support::little, 8, true> > *Obj =
190 new DyldELFObject<ELFType<support::little, 8, true> >(
191 Buffer->getMemBuffer(), ec);
192 return new ELFObjectImage<ELFType<support::little, 8, true> >(Buffer, Obj);
195 llvm_unreachable("Unexpected ELF format");
198 RuntimeDyldELF::~RuntimeDyldELF() {
201 void RuntimeDyldELF::resolveX86_64Relocation(const SectionEntry &Section,
208 llvm_unreachable("Relocation type not implemented yet!");
210 case ELF::R_X86_64_64: {
211 uint64_t *Target = reinterpret_cast<uint64_t*>(Section.Address + Offset);
212 *Target = Value + Addend;
213 DEBUG(dbgs() << "Writing " << format("%p", (Value + Addend))
214 << " at " << format("%p\n",Target));
217 case ELF::R_X86_64_32:
218 case ELF::R_X86_64_32S: {
220 assert((Type == ELF::R_X86_64_32 && (Value <= UINT32_MAX)) ||
221 (Type == ELF::R_X86_64_32S &&
222 ((int64_t)Value <= INT32_MAX && (int64_t)Value >= INT32_MIN)));
223 uint32_t TruncatedAddr = (Value & 0xFFFFFFFF);
224 uint32_t *Target = reinterpret_cast<uint32_t*>(Section.Address + Offset);
225 *Target = TruncatedAddr;
226 DEBUG(dbgs() << "Writing " << format("%p", TruncatedAddr)
227 << " at " << format("%p\n",Target));
230 case ELF::R_X86_64_PC32: {
231 // Get the placeholder value from the generated object since
232 // a previous relocation attempt may have overwritten the loaded version
233 uint32_t *Placeholder = reinterpret_cast<uint32_t*>(Section.ObjAddress
235 uint32_t *Target = reinterpret_cast<uint32_t*>(Section.Address + Offset);
236 uint64_t FinalAddress = Section.LoadAddress + Offset;
237 int64_t RealOffset = *Placeholder + Value + Addend - FinalAddress;
238 assert(RealOffset <= INT32_MAX && RealOffset >= INT32_MIN);
239 int32_t TruncOffset = (RealOffset & 0xFFFFFFFF);
240 *Target = TruncOffset;
246 void RuntimeDyldELF::resolveX86Relocation(const SectionEntry &Section,
252 case ELF::R_386_32: {
253 // Get the placeholder value from the generated object since
254 // a previous relocation attempt may have overwritten the loaded version
255 uint32_t *Placeholder = reinterpret_cast<uint32_t*>(Section.ObjAddress
257 uint32_t *Target = reinterpret_cast<uint32_t*>(Section.Address + Offset);
258 *Target = *Placeholder + Value + Addend;
261 case ELF::R_386_PC32: {
262 // Get the placeholder value from the generated object since
263 // a previous relocation attempt may have overwritten the loaded version
264 uint32_t *Placeholder = reinterpret_cast<uint32_t*>(Section.ObjAddress
266 uint32_t *Target = reinterpret_cast<uint32_t*>(Section.Address + Offset);
267 uint32_t FinalAddress = ((Section.LoadAddress + Offset) & 0xFFFFFFFF);
268 uint32_t RealOffset = *Placeholder + Value + Addend - FinalAddress;
269 *Target = RealOffset;
273 // There are other relocation types, but it appears these are the
274 // only ones currently used by the LLVM ELF object writer
275 llvm_unreachable("Relocation type not implemented yet!");
280 void RuntimeDyldELF::resolveAArch64Relocation(const SectionEntry &Section,
285 uint32_t *TargetPtr = reinterpret_cast<uint32_t*>(Section.Address + Offset);
286 uint64_t FinalAddress = Section.LoadAddress + Offset;
288 DEBUG(dbgs() << "resolveAArch64Relocation, LocalAddress: 0x"
289 << format("%llx", Section.Address + Offset)
290 << " FinalAddress: 0x" << format("%llx",FinalAddress)
291 << " Value: 0x" << format("%llx",Value)
292 << " Type: 0x" << format("%x",Type)
293 << " Addend: 0x" << format("%llx",Addend)
298 llvm_unreachable("Relocation type not implemented yet!");
300 case ELF::R_AARCH64_ABS64: {
301 uint64_t *TargetPtr = reinterpret_cast<uint64_t*>(Section.Address + Offset);
302 *TargetPtr = Value + Addend;
305 case ELF::R_AARCH64_PREL32: { // test-shift.ll (.eh_frame)
306 uint64_t Result = Value + Addend - FinalAddress;
307 assert(static_cast<int64_t>(Result) >= INT32_MIN &&
308 static_cast<int64_t>(Result) <= UINT32_MAX);
309 *TargetPtr = static_cast<uint32_t>(Result & 0xffffffffU);
312 case ELF::R_AARCH64_CALL26: // fallthrough
313 case ELF::R_AARCH64_JUMP26: {
314 // Operation: S+A-P. Set Call or B immediate value to bits fff_fffc of the
316 uint64_t BranchImm = Value + Addend - FinalAddress;
318 // "Check that -2^27 <= result < 2^27".
319 assert(-(1LL << 27) <= static_cast<int64_t>(BranchImm) &&
320 static_cast<int64_t>(BranchImm) < (1LL << 27));
321 // Immediate goes in bits 25:0 of B and BL.
322 *TargetPtr |= static_cast<uint32_t>(BranchImm & 0xffffffcU) >> 2;
325 case ELF::R_AARCH64_MOVW_UABS_G3: {
326 uint64_t Result = Value + Addend;
327 // Immediate goes in bits 20:5 of MOVZ/MOVK instruction
328 *TargetPtr |= Result >> (48 - 5);
329 // Shift is "lsl #48", in bits 22:21
330 *TargetPtr |= 3 << 21;
333 case ELF::R_AARCH64_MOVW_UABS_G2_NC: {
334 uint64_t Result = Value + Addend;
335 // Immediate goes in bits 20:5 of MOVZ/MOVK instruction
336 *TargetPtr |= ((Result & 0xffff00000000ULL) >> (32 - 5));
337 // Shift is "lsl #32", in bits 22:21
338 *TargetPtr |= 2 << 21;
341 case ELF::R_AARCH64_MOVW_UABS_G1_NC: {
342 uint64_t Result = Value + Addend;
343 // Immediate goes in bits 20:5 of MOVZ/MOVK instruction
344 *TargetPtr |= ((Result & 0xffff0000U) >> (16 - 5));
345 // Shift is "lsl #16", in bits 22:21
346 *TargetPtr |= 1 << 21;
349 case ELF::R_AARCH64_MOVW_UABS_G0_NC: {
350 uint64_t Result = Value + Addend;
351 // Immediate goes in bits 20:5 of MOVZ/MOVK instruction
352 *TargetPtr |= ((Result & 0xffffU) << 5);
353 // Shift is "lsl #0", in bits 22:21. No action needed.
359 void RuntimeDyldELF::resolveARMRelocation(const SectionEntry &Section,
364 // TODO: Add Thumb relocations.
365 uint32_t* TargetPtr = (uint32_t*)(Section.Address + Offset);
366 uint32_t FinalAddress = ((Section.LoadAddress + Offset) & 0xFFFFFFFF);
369 DEBUG(dbgs() << "resolveARMRelocation, LocalAddress: "
370 << Section.Address + Offset
371 << " FinalAddress: " << format("%p",FinalAddress)
372 << " Value: " << format("%x",Value)
373 << " Type: " << format("%x",Type)
374 << " Addend: " << format("%x",Addend)
379 llvm_unreachable("Not implemented relocation type!");
381 // Write a 32bit value to relocation address, taking into account the
382 // implicit addend encoded in the target.
383 case ELF::R_ARM_TARGET1 :
384 case ELF::R_ARM_ABS32 :
388 // Write first 16 bit of 32 bit value to the mov instruction.
389 // Last 4 bit should be shifted.
390 case ELF::R_ARM_MOVW_ABS_NC :
391 // We are not expecting any other addend in the relocation address.
392 // Using 0x000F0FFF because MOVW has its 16 bit immediate split into 2
393 // non-contiguous fields.
394 assert((*TargetPtr & 0x000F0FFF) == 0);
395 Value = Value & 0xFFFF;
396 *TargetPtr |= Value & 0xFFF;
397 *TargetPtr |= ((Value >> 12) & 0xF) << 16;
400 // Write last 16 bit of 32 bit value to the mov instruction.
401 // Last 4 bit should be shifted.
402 case ELF::R_ARM_MOVT_ABS :
403 // We are not expecting any other addend in the relocation address.
404 // Use 0x000F0FFF for the same reason as R_ARM_MOVW_ABS_NC.
405 assert((*TargetPtr & 0x000F0FFF) == 0);
406 Value = (Value >> 16) & 0xFFFF;
407 *TargetPtr |= Value & 0xFFF;
408 *TargetPtr |= ((Value >> 12) & 0xF) << 16;
411 // Write 24 bit relative value to the branch instruction.
412 case ELF::R_ARM_PC24 : // Fall through.
413 case ELF::R_ARM_CALL : // Fall through.
414 case ELF::R_ARM_JUMP24 :
415 int32_t RelValue = static_cast<int32_t>(Value - FinalAddress - 8);
416 RelValue = (RelValue & 0x03FFFFFC) >> 2;
417 *TargetPtr &= 0xFF000000;
418 *TargetPtr |= RelValue;
423 void RuntimeDyldELF::resolveMIPSRelocation(const SectionEntry &Section,
428 uint32_t* TargetPtr = (uint32_t*)(Section.Address + Offset);
431 DEBUG(dbgs() << "resolveMipselocation, LocalAddress: "
432 << Section.Address + Offset
434 << format("%p",Section.LoadAddress + Offset)
435 << " Value: " << format("%x",Value)
436 << " Type: " << format("%x",Type)
437 << " Addend: " << format("%x",Addend)
442 llvm_unreachable("Not implemented relocation type!");
445 *TargetPtr = Value + (*TargetPtr);
448 *TargetPtr = ((*TargetPtr) & 0xfc000000) | (( Value & 0x0fffffff) >> 2);
450 case ELF::R_MIPS_HI16:
451 // Get the higher 16-bits. Also add 1 if bit 15 is 1.
452 Value += ((*TargetPtr) & 0x0000ffff) << 16;
453 *TargetPtr = ((*TargetPtr) & 0xffff0000) |
454 (((Value + 0x8000) >> 16) & 0xffff);
456 case ELF::R_MIPS_LO16:
457 Value += ((*TargetPtr) & 0x0000ffff);
458 *TargetPtr = ((*TargetPtr) & 0xffff0000) | (Value & 0xffff);
463 // Return the .TOC. section address to R_PPC64_TOC relocations.
464 uint64_t RuntimeDyldELF::findPPC64TOC() const {
465 // The TOC consists of sections .got, .toc, .tocbss, .plt in that
466 // order. The TOC starts where the first of these sections starts.
467 SectionList::const_iterator it = Sections.begin();
468 SectionList::const_iterator ite = Sections.end();
469 for (; it != ite; ++it) {
470 if (it->Name == ".got" ||
471 it->Name == ".toc" ||
472 it->Name == ".tocbss" ||
477 // This may happen for
478 // * references to TOC base base (sym@toc, .odp relocation) without
480 // In this case just use the first section (which is usually
481 // the .odp) since the code won't reference the .toc base
483 it = Sections.begin();
486 // Per the ppc64-elf-linux ABI, The TOC base is TOC value plus 0x8000
487 // thus permitting a full 64 Kbytes segment.
488 return it->LoadAddress + 0x8000;
491 // Returns the sections and offset associated with the ODP entry referenced
493 void RuntimeDyldELF::findOPDEntrySection(ObjectImage &Obj,
494 ObjSectionToIDMap &LocalSections,
495 RelocationValueRef &Rel) {
496 // Get the ELF symbol value (st_value) to compare with Relocation offset in
500 for (section_iterator si = Obj.begin_sections(),
501 se = Obj.end_sections(); si != se; si.increment(err)) {
502 StringRef SectionName;
503 check(si->getName(SectionName));
504 if (SectionName != ".opd")
507 for (relocation_iterator i = si->begin_relocations(),
508 e = si->end_relocations(); i != e;) {
511 // The R_PPC64_ADDR64 relocation indicates the first field
514 check(i->getType(TypeFunc));
515 if (TypeFunc != ELF::R_PPC64_ADDR64) {
520 SymbolRef TargetSymbol;
521 uint64_t TargetSymbolOffset;
522 int64_t TargetAdditionalInfo;
523 check(i->getSymbol(TargetSymbol));
524 check(i->getOffset(TargetSymbolOffset));
525 check(i->getAdditionalInfo(TargetAdditionalInfo));
527 i = i.increment(err);
532 // Just check if following relocation is a R_PPC64_TOC
534 check(i->getType(TypeTOC));
535 if (TypeTOC != ELF::R_PPC64_TOC)
538 // Finally compares the Symbol value and the target symbol offset
539 // to check if this .opd entry refers to the symbol the relocation
541 if (Rel.Addend != (intptr_t)TargetSymbolOffset)
544 section_iterator tsi(Obj.end_sections());
545 check(TargetSymbol.getSection(tsi));
546 Rel.SectionID = findOrEmitSection(Obj, (*tsi), true, LocalSections);
547 Rel.Addend = (intptr_t)TargetAdditionalInfo;
551 llvm_unreachable("Attempting to get address of ODP entry!");
554 // Relocation masks following the #lo(value), #hi(value), #higher(value),
555 // and #highest(value) macros defined in section 4.5.1. Relocation Types
556 // in PPC-elf64abi document.
559 uint16_t applyPPClo (uint64_t value)
561 return value & 0xffff;
565 uint16_t applyPPChi (uint64_t value)
567 return (value >> 16) & 0xffff;
571 uint16_t applyPPChigher (uint64_t value)
573 return (value >> 32) & 0xffff;
577 uint16_t applyPPChighest (uint64_t value)
579 return (value >> 48) & 0xffff;
582 void RuntimeDyldELF::resolvePPC64Relocation(const SectionEntry &Section,
587 uint8_t* LocalAddress = Section.Address + Offset;
590 llvm_unreachable("Relocation type not implemented yet!");
592 case ELF::R_PPC64_ADDR16_LO :
593 writeInt16BE(LocalAddress, applyPPClo (Value + Addend));
595 case ELF::R_PPC64_ADDR16_HI :
596 writeInt16BE(LocalAddress, applyPPChi (Value + Addend));
598 case ELF::R_PPC64_ADDR16_HIGHER :
599 writeInt16BE(LocalAddress, applyPPChigher (Value + Addend));
601 case ELF::R_PPC64_ADDR16_HIGHEST :
602 writeInt16BE(LocalAddress, applyPPChighest (Value + Addend));
604 case ELF::R_PPC64_ADDR14 : {
605 assert(((Value + Addend) & 3) == 0);
606 // Preserve the AA/LK bits in the branch instruction
607 uint8_t aalk = *(LocalAddress+3);
608 writeInt16BE(LocalAddress + 2, (aalk & 3) | ((Value + Addend) & 0xfffc));
610 case ELF::R_PPC64_ADDR32 : {
611 int32_t Result = static_cast<int32_t>(Value + Addend);
612 if (SignExtend32<32>(Result) != Result)
613 llvm_unreachable("Relocation R_PPC64_ADDR32 overflow");
614 writeInt32BE(LocalAddress, Result);
616 case ELF::R_PPC64_REL24 : {
617 uint64_t FinalAddress = (Section.LoadAddress + Offset);
618 int32_t delta = static_cast<int32_t>(Value - FinalAddress + Addend);
619 if (SignExtend32<24>(delta) != delta)
620 llvm_unreachable("Relocation R_PPC64_REL24 overflow");
621 // Generates a 'bl <address>' instruction
622 writeInt32BE(LocalAddress, 0x48000001 | (delta & 0x03FFFFFC));
624 case ELF::R_PPC64_REL32 : {
625 uint64_t FinalAddress = (Section.LoadAddress + Offset);
626 int32_t delta = static_cast<int32_t>(Value - FinalAddress + Addend);
627 if (SignExtend32<32>(delta) != delta)
628 llvm_unreachable("Relocation R_PPC64_REL32 overflow");
629 writeInt32BE(LocalAddress, delta);
631 case ELF::R_PPC64_REL64: {
632 uint64_t FinalAddress = (Section.LoadAddress + Offset);
633 uint64_t Delta = Value - FinalAddress + Addend;
634 writeInt64BE(LocalAddress, Delta);
636 case ELF::R_PPC64_ADDR64 :
637 writeInt64BE(LocalAddress, Value + Addend);
639 case ELF::R_PPC64_TOC :
640 writeInt64BE(LocalAddress, findPPC64TOC());
642 case ELF::R_PPC64_TOC16 : {
643 uint64_t TOCStart = findPPC64TOC();
644 Value = applyPPClo((Value + Addend) - TOCStart);
645 writeInt16BE(LocalAddress, applyPPClo(Value));
647 case ELF::R_PPC64_TOC16_DS : {
648 uint64_t TOCStart = findPPC64TOC();
649 Value = ((Value + Addend) - TOCStart);
650 writeInt16BE(LocalAddress, applyPPClo(Value));
655 void RuntimeDyldELF::resolveSystemZRelocation(const SectionEntry &Section,
660 uint8_t *LocalAddress = Section.Address + Offset;
663 llvm_unreachable("Relocation type not implemented yet!");
665 case ELF::R_390_PC16DBL:
666 case ELF::R_390_PLT16DBL: {
667 int64_t Delta = (Value + Addend) - (Section.LoadAddress + Offset);
668 assert(int16_t(Delta / 2) * 2 == Delta && "R_390_PC16DBL overflow");
669 writeInt16BE(LocalAddress, Delta / 2);
672 case ELF::R_390_PC32DBL:
673 case ELF::R_390_PLT32DBL: {
674 int64_t Delta = (Value + Addend) - (Section.LoadAddress + Offset);
675 assert(int32_t(Delta / 2) * 2 == Delta && "R_390_PC32DBL overflow");
676 writeInt32BE(LocalAddress, Delta / 2);
679 case ELF::R_390_PC32: {
680 int64_t Delta = (Value + Addend) - (Section.LoadAddress + Offset);
681 assert(int32_t(Delta) == Delta && "R_390_PC32 overflow");
682 writeInt32BE(LocalAddress, Delta);
686 writeInt64BE(LocalAddress, Value + Addend);
691 void RuntimeDyldELF::resolveRelocation(const RelocationEntry &RE,
693 const SectionEntry &Section = Sections[RE.SectionID];
694 return resolveRelocation(Section, RE.Offset, Value, RE.RelType, RE.Addend);
697 void RuntimeDyldELF::resolveRelocation(const SectionEntry &Section,
704 resolveX86_64Relocation(Section, Offset, Value, Type, Addend);
707 resolveX86Relocation(Section, Offset,
708 (uint32_t)(Value & 0xffffffffL), Type,
709 (uint32_t)(Addend & 0xffffffffL));
711 case Triple::aarch64:
712 resolveAArch64Relocation(Section, Offset, Value, Type, Addend);
714 case Triple::arm: // Fall through.
716 resolveARMRelocation(Section, Offset,
717 (uint32_t)(Value & 0xffffffffL), Type,
718 (uint32_t)(Addend & 0xffffffffL));
720 case Triple::mips: // Fall through.
722 resolveMIPSRelocation(Section, Offset,
723 (uint32_t)(Value & 0xffffffffL), Type,
724 (uint32_t)(Addend & 0xffffffffL));
727 resolvePPC64Relocation(Section, Offset, Value, Type, Addend);
729 case Triple::systemz:
730 resolveSystemZRelocation(Section, Offset, Value, Type, Addend);
732 default: llvm_unreachable("Unsupported CPU type!");
736 void RuntimeDyldELF::processRelocationRef(unsigned SectionID,
739 ObjSectionToIDMap &ObjSectionToID,
740 const SymbolTableMap &Symbols,
743 Check(RelI.getType(RelType));
745 Check(RelI.getAdditionalInfo(Addend));
747 Check(RelI.getSymbol(Symbol));
749 // Obtain the symbol name which is referenced in the relocation
750 StringRef TargetName;
751 Symbol.getName(TargetName);
752 DEBUG(dbgs() << "\t\tRelType: " << RelType
753 << " Addend: " << Addend
754 << " TargetName: " << TargetName
756 RelocationValueRef Value;
757 // First search for the symbol in the local symbol table
758 SymbolTableMap::const_iterator lsi = Symbols.find(TargetName.data());
759 SymbolRef::Type SymType;
760 Symbol.getType(SymType);
761 if (lsi != Symbols.end()) {
762 Value.SectionID = lsi->second.first;
763 Value.Addend = lsi->second.second + Addend;
765 // Search for the symbol in the global symbol table
766 SymbolTableMap::const_iterator gsi =
767 GlobalSymbolTable.find(TargetName.data());
768 if (gsi != GlobalSymbolTable.end()) {
769 Value.SectionID = gsi->second.first;
770 Value.Addend = gsi->second.second + Addend;
773 case SymbolRef::ST_Debug: {
774 // TODO: Now ELF SymbolRef::ST_Debug = STT_SECTION, it's not obviously
775 // and can be changed by another developers. Maybe best way is add
776 // a new symbol type ST_Section to SymbolRef and use it.
777 section_iterator si(Obj.end_sections());
778 Symbol.getSection(si);
779 if (si == Obj.end_sections())
780 llvm_unreachable("Symbol section not found, bad object file format!");
781 DEBUG(dbgs() << "\t\tThis is section symbol\n");
782 // Default to 'true' in case isText fails (though it never does).
785 Value.SectionID = findOrEmitSection(Obj,
789 Value.Addend = Addend;
792 case SymbolRef::ST_Unknown: {
793 Value.SymbolName = TargetName.data();
794 Value.Addend = Addend;
798 llvm_unreachable("Unresolved symbol type!");
804 Check(RelI.getOffset(Offset));
806 DEBUG(dbgs() << "\t\tSectionID: " << SectionID
807 << " Offset: " << Offset
809 if (Arch == Triple::aarch64 &&
810 (RelType == ELF::R_AARCH64_CALL26 ||
811 RelType == ELF::R_AARCH64_JUMP26)) {
812 // This is an AArch64 branch relocation, need to use a stub function.
813 DEBUG(dbgs() << "\t\tThis is an AArch64 branch relocation.");
814 SectionEntry &Section = Sections[SectionID];
816 // Look for an existing stub.
817 StubMap::const_iterator i = Stubs.find(Value);
818 if (i != Stubs.end()) {
819 resolveRelocation(Section, Offset,
820 (uint64_t)Section.Address + i->second, RelType, 0);
821 DEBUG(dbgs() << " Stub function found\n");
823 // Create a new stub function.
824 DEBUG(dbgs() << " Create a new stub function\n");
825 Stubs[Value] = Section.StubOffset;
826 uint8_t *StubTargetAddr = createStubFunction(Section.Address +
829 RelocationEntry REmovz_g3(SectionID,
830 StubTargetAddr - Section.Address,
831 ELF::R_AARCH64_MOVW_UABS_G3, Value.Addend);
832 RelocationEntry REmovk_g2(SectionID,
833 StubTargetAddr - Section.Address + 4,
834 ELF::R_AARCH64_MOVW_UABS_G2_NC, Value.Addend);
835 RelocationEntry REmovk_g1(SectionID,
836 StubTargetAddr - Section.Address + 8,
837 ELF::R_AARCH64_MOVW_UABS_G1_NC, Value.Addend);
838 RelocationEntry REmovk_g0(SectionID,
839 StubTargetAddr - Section.Address + 12,
840 ELF::R_AARCH64_MOVW_UABS_G0_NC, Value.Addend);
842 if (Value.SymbolName) {
843 addRelocationForSymbol(REmovz_g3, Value.SymbolName);
844 addRelocationForSymbol(REmovk_g2, Value.SymbolName);
845 addRelocationForSymbol(REmovk_g1, Value.SymbolName);
846 addRelocationForSymbol(REmovk_g0, Value.SymbolName);
848 addRelocationForSection(REmovz_g3, Value.SectionID);
849 addRelocationForSection(REmovk_g2, Value.SectionID);
850 addRelocationForSection(REmovk_g1, Value.SectionID);
851 addRelocationForSection(REmovk_g0, Value.SectionID);
853 resolveRelocation(Section, Offset,
854 (uint64_t)Section.Address + Section.StubOffset,
856 Section.StubOffset += getMaxStubSize();
858 } else if (Arch == Triple::arm &&
859 (RelType == ELF::R_ARM_PC24 ||
860 RelType == ELF::R_ARM_CALL ||
861 RelType == ELF::R_ARM_JUMP24)) {
862 // This is an ARM branch relocation, need to use a stub function.
863 DEBUG(dbgs() << "\t\tThis is an ARM branch relocation.");
864 SectionEntry &Section = Sections[SectionID];
866 // Look for an existing stub.
867 StubMap::const_iterator i = Stubs.find(Value);
868 if (i != Stubs.end()) {
869 resolveRelocation(Section, Offset,
870 (uint64_t)Section.Address + i->second, RelType, 0);
871 DEBUG(dbgs() << " Stub function found\n");
873 // Create a new stub function.
874 DEBUG(dbgs() << " Create a new stub function\n");
875 Stubs[Value] = Section.StubOffset;
876 uint8_t *StubTargetAddr = createStubFunction(Section.Address +
878 RelocationEntry RE(SectionID, StubTargetAddr - Section.Address,
879 ELF::R_ARM_ABS32, Value.Addend);
880 if (Value.SymbolName)
881 addRelocationForSymbol(RE, Value.SymbolName);
883 addRelocationForSection(RE, Value.SectionID);
885 resolveRelocation(Section, Offset,
886 (uint64_t)Section.Address + Section.StubOffset,
888 Section.StubOffset += getMaxStubSize();
890 } else if ((Arch == Triple::mipsel || Arch == Triple::mips) &&
891 RelType == ELF::R_MIPS_26) {
892 // This is an Mips branch relocation, need to use a stub function.
893 DEBUG(dbgs() << "\t\tThis is a Mips branch relocation.");
894 SectionEntry &Section = Sections[SectionID];
895 uint8_t *Target = Section.Address + Offset;
896 uint32_t *TargetAddress = (uint32_t *)Target;
898 // Extract the addend from the instruction.
899 uint32_t Addend = ((*TargetAddress) & 0x03ffffff) << 2;
901 Value.Addend += Addend;
903 // Look up for existing stub.
904 StubMap::const_iterator i = Stubs.find(Value);
905 if (i != Stubs.end()) {
906 resolveRelocation(Section, Offset,
907 (uint64_t)Section.Address + i->second, RelType, 0);
908 DEBUG(dbgs() << " Stub function found\n");
910 // Create a new stub function.
911 DEBUG(dbgs() << " Create a new stub function\n");
912 Stubs[Value] = Section.StubOffset;
913 uint8_t *StubTargetAddr = createStubFunction(Section.Address +
916 // Creating Hi and Lo relocations for the filled stub instructions.
917 RelocationEntry REHi(SectionID,
918 StubTargetAddr - Section.Address,
919 ELF::R_MIPS_HI16, Value.Addend);
920 RelocationEntry RELo(SectionID,
921 StubTargetAddr - Section.Address + 4,
922 ELF::R_MIPS_LO16, Value.Addend);
924 if (Value.SymbolName) {
925 addRelocationForSymbol(REHi, Value.SymbolName);
926 addRelocationForSymbol(RELo, Value.SymbolName);
928 addRelocationForSection(REHi, Value.SectionID);
929 addRelocationForSection(RELo, Value.SectionID);
932 resolveRelocation(Section, Offset,
933 (uint64_t)Section.Address + Section.StubOffset,
935 Section.StubOffset += getMaxStubSize();
937 } else if (Arch == Triple::ppc64) {
938 if (RelType == ELF::R_PPC64_REL24) {
939 // A PPC branch relocation will need a stub function if the target is
940 // an external symbol (Symbol::ST_Unknown) or if the target address
941 // is not within the signed 24-bits branch address.
942 SectionEntry &Section = Sections[SectionID];
943 uint8_t *Target = Section.Address + Offset;
944 bool RangeOverflow = false;
945 if (SymType != SymbolRef::ST_Unknown) {
946 // A function call may points to the .opd entry, so the final symbol value
947 // in calculated based in the relocation values in .opd section.
948 findOPDEntrySection(Obj, ObjSectionToID, Value);
949 uint8_t *RelocTarget = Sections[Value.SectionID].Address + Value.Addend;
950 int32_t delta = static_cast<int32_t>(Target - RelocTarget);
951 // If it is within 24-bits branch range, just set the branch target
952 if (SignExtend32<24>(delta) == delta) {
953 RelocationEntry RE(SectionID, Offset, RelType, Value.Addend);
954 if (Value.SymbolName)
955 addRelocationForSymbol(RE, Value.SymbolName);
957 addRelocationForSection(RE, Value.SectionID);
959 RangeOverflow = true;
962 if (SymType == SymbolRef::ST_Unknown || RangeOverflow == true) {
963 // It is an external symbol (SymbolRef::ST_Unknown) or within a range
964 // larger than 24-bits.
965 StubMap::const_iterator i = Stubs.find(Value);
966 if (i != Stubs.end()) {
967 // Symbol function stub already created, just relocate to it
968 resolveRelocation(Section, Offset,
969 (uint64_t)Section.Address + i->second, RelType, 0);
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 = createStubFunction(Section.Address +
977 RelocationEntry RE(SectionID, StubTargetAddr - Section.Address,
978 ELF::R_PPC64_ADDR64, Value.Addend);
980 // Generates the 64-bits address loads as exemplified in section
981 // 4.5.1 in PPC64 ELF ABI.
982 RelocationEntry REhst(SectionID,
983 StubTargetAddr - Section.Address + 2,
984 ELF::R_PPC64_ADDR16_HIGHEST, Value.Addend);
985 RelocationEntry REhr(SectionID,
986 StubTargetAddr - Section.Address + 6,
987 ELF::R_PPC64_ADDR16_HIGHER, Value.Addend);
988 RelocationEntry REh(SectionID,
989 StubTargetAddr - Section.Address + 14,
990 ELF::R_PPC64_ADDR16_HI, Value.Addend);
991 RelocationEntry REl(SectionID,
992 StubTargetAddr - Section.Address + 18,
993 ELF::R_PPC64_ADDR16_LO, Value.Addend);
995 if (Value.SymbolName) {
996 addRelocationForSymbol(REhst, Value.SymbolName);
997 addRelocationForSymbol(REhr, Value.SymbolName);
998 addRelocationForSymbol(REh, Value.SymbolName);
999 addRelocationForSymbol(REl, Value.SymbolName);
1001 addRelocationForSection(REhst, Value.SectionID);
1002 addRelocationForSection(REhr, Value.SectionID);
1003 addRelocationForSection(REh, Value.SectionID);
1004 addRelocationForSection(REl, Value.SectionID);
1007 resolveRelocation(Section, Offset,
1008 (uint64_t)Section.Address + Section.StubOffset,
1010 if (SymType == SymbolRef::ST_Unknown)
1011 // Restore the TOC for external calls
1012 writeInt32BE(Target+4, 0xE8410028); // ld r2,40(r1)
1013 Section.StubOffset += getMaxStubSize();
1017 RelocationEntry RE(SectionID, Offset, RelType, Value.Addend);
1018 // Extra check to avoid relocation againt empty symbols (usually
1019 // the R_PPC64_TOC).
1020 if (Value.SymbolName && !TargetName.empty())
1021 addRelocationForSymbol(RE, Value.SymbolName);
1023 addRelocationForSection(RE, Value.SectionID);
1025 } else if (Arch == Triple::systemz &&
1026 (RelType == ELF::R_390_PLT32DBL ||
1027 RelType == ELF::R_390_GOTENT)) {
1028 // Create function stubs for both PLT and GOT references, regardless of
1029 // whether the GOT reference is to data or code. The stub contains the
1030 // full address of the symbol, as needed by GOT references, and the
1031 // executable part only adds an overhead of 8 bytes.
1033 // We could try to conserve space by allocating the code and data
1034 // parts of the stub separately. However, as things stand, we allocate
1035 // a stub for every relocation, so using a GOT in JIT code should be
1036 // no less space efficient than using an explicit constant pool.
1037 DEBUG(dbgs() << "\t\tThis is a SystemZ indirect relocation.");
1038 SectionEntry &Section = Sections[SectionID];
1040 // Look for an existing stub.
1041 StubMap::const_iterator i = Stubs.find(Value);
1042 uintptr_t StubAddress;
1043 if (i != Stubs.end()) {
1044 StubAddress = uintptr_t(Section.Address) + i->second;
1045 DEBUG(dbgs() << " Stub function found\n");
1047 // Create a new stub function.
1048 DEBUG(dbgs() << " Create a new stub function\n");
1050 uintptr_t BaseAddress = uintptr_t(Section.Address);
1051 uintptr_t StubAlignment = getStubAlignment();
1052 StubAddress = (BaseAddress + Section.StubOffset +
1053 StubAlignment - 1) & -StubAlignment;
1054 unsigned StubOffset = StubAddress - BaseAddress;
1056 Stubs[Value] = StubOffset;
1057 createStubFunction((uint8_t *)StubAddress);
1058 RelocationEntry RE(SectionID, StubOffset + 8,
1059 ELF::R_390_64, Value.Addend - Addend);
1060 if (Value.SymbolName)
1061 addRelocationForSymbol(RE, Value.SymbolName);
1063 addRelocationForSection(RE, Value.SectionID);
1064 Section.StubOffset = StubOffset + getMaxStubSize();
1067 if (RelType == ELF::R_390_GOTENT)
1068 resolveRelocation(Section, Offset, StubAddress + 8,
1069 ELF::R_390_PC32DBL, Addend);
1071 resolveRelocation(Section, Offset, StubAddress, RelType, Addend);
1073 RelocationEntry RE(SectionID, Offset, RelType, Value.Addend);
1074 if (Value.SymbolName)
1075 addRelocationForSymbol(RE, Value.SymbolName);
1077 addRelocationForSection(RE, Value.SectionID);
1081 bool RuntimeDyldELF::isCompatibleFormat(const ObjectBuffer *Buffer) const {
1082 if (Buffer->getBufferSize() < strlen(ELF::ElfMagic))
1084 return (memcmp(Buffer->getBufferStart(), ELF::ElfMagic, strlen(ELF::ElfMagic))) == 0;