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/ELFObjectFile.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 void RuntimeDyldELF::registerEHFrames() {
157 for (int i = 0, e = UnregisteredEHFrameSections.size(); i != e; ++i) {
158 SID EHFrameSID = UnregisteredEHFrameSections[i];
159 uint8_t *EHFrameAddr = Sections[EHFrameSID].Address;
160 uint64_t EHFrameLoadAddr = Sections[EHFrameSID].LoadAddress;
161 size_t EHFrameSize = Sections[EHFrameSID].Size;
162 MemMgr->registerEHFrames(EHFrameAddr, EHFrameLoadAddr, EHFrameSize);
163 RegisteredEHFrameSections.push_back(EHFrameSID);
165 UnregisteredEHFrameSections.clear();
168 void RuntimeDyldELF::deregisterEHFrames() {
171 for (int i = 0, e = RegisteredEHFrameSections.size(); i != e; ++i) {
172 SID EHFrameSID = RegisteredEHFrameSections[i];
173 uint8_t *EHFrameAddr = Sections[EHFrameSID].Address;
174 uint64_t EHFrameLoadAddr = Sections[EHFrameSID].LoadAddress;
175 size_t EHFrameSize = Sections[EHFrameSID].Size;
176 MemMgr->deregisterEHFrames(EHFrameAddr, EHFrameLoadAddr, EHFrameSize);
178 RegisteredEHFrameSections.clear();
181 ObjectImage *RuntimeDyldELF::createObjectImage(ObjectBuffer *Buffer) {
182 if (Buffer->getBufferSize() < ELF::EI_NIDENT)
183 llvm_unreachable("Unexpected ELF object size");
184 std::pair<unsigned char, unsigned char> Ident = std::make_pair(
185 (uint8_t)Buffer->getBufferStart()[ELF::EI_CLASS],
186 (uint8_t)Buffer->getBufferStart()[ELF::EI_DATA]);
189 if (Ident.first == ELF::ELFCLASS32 && Ident.second == ELF::ELFDATA2LSB) {
190 DyldELFObject<ELFType<support::little, 4, false> > *Obj =
191 new DyldELFObject<ELFType<support::little, 4, false> >(
192 Buffer->getMemBuffer(), ec);
193 return new ELFObjectImage<ELFType<support::little, 4, false> >(Buffer, Obj);
195 else if (Ident.first == ELF::ELFCLASS32 && Ident.second == ELF::ELFDATA2MSB) {
196 DyldELFObject<ELFType<support::big, 4, false> > *Obj =
197 new DyldELFObject<ELFType<support::big, 4, false> >(
198 Buffer->getMemBuffer(), ec);
199 return new ELFObjectImage<ELFType<support::big, 4, false> >(Buffer, Obj);
201 else if (Ident.first == ELF::ELFCLASS64 && Ident.second == ELF::ELFDATA2MSB) {
202 DyldELFObject<ELFType<support::big, 8, true> > *Obj =
203 new DyldELFObject<ELFType<support::big, 8, true> >(
204 Buffer->getMemBuffer(), ec);
205 return new ELFObjectImage<ELFType<support::big, 8, true> >(Buffer, Obj);
207 else if (Ident.first == ELF::ELFCLASS64 && Ident.second == ELF::ELFDATA2LSB) {
208 DyldELFObject<ELFType<support::little, 8, true> > *Obj =
209 new DyldELFObject<ELFType<support::little, 8, true> >(
210 Buffer->getMemBuffer(), ec);
211 return new ELFObjectImage<ELFType<support::little, 8, true> >(Buffer, Obj);
214 llvm_unreachable("Unexpected ELF format");
217 RuntimeDyldELF::~RuntimeDyldELF() {
220 void RuntimeDyldELF::resolveX86_64Relocation(const SectionEntry &Section,
225 uint64_t SymOffset) {
228 llvm_unreachable("Relocation type not implemented yet!");
230 case ELF::R_X86_64_64: {
231 uint64_t *Target = reinterpret_cast<uint64_t*>(Section.Address + Offset);
232 *Target = Value + Addend;
233 DEBUG(dbgs() << "Writing " << format("%p", (Value + Addend))
234 << " at " << format("%p\n",Target));
237 case ELF::R_X86_64_32:
238 case ELF::R_X86_64_32S: {
240 assert((Type == ELF::R_X86_64_32 && (Value <= UINT32_MAX)) ||
241 (Type == ELF::R_X86_64_32S &&
242 ((int64_t)Value <= INT32_MAX && (int64_t)Value >= INT32_MIN)));
243 uint32_t TruncatedAddr = (Value & 0xFFFFFFFF);
244 uint32_t *Target = reinterpret_cast<uint32_t*>(Section.Address + Offset);
245 *Target = TruncatedAddr;
246 DEBUG(dbgs() << "Writing " << format("%p", TruncatedAddr)
247 << " at " << format("%p\n",Target));
250 case ELF::R_X86_64_GOTPCREL: {
251 // findGOTEntry returns the 'G + GOT' part of the relocation calculation
252 // based on the load/target address of the GOT (not the current/local addr).
253 uint64_t GOTAddr = findGOTEntry(Value, SymOffset);
254 uint32_t *Target = reinterpret_cast<uint32_t*>(Section.Address + Offset);
255 uint64_t FinalAddress = Section.LoadAddress + Offset;
256 // The processRelocationRef method combines the symbol offset and the addend
257 // and in most cases that's what we want. For this relocation type, we need
258 // the raw addend, so we subtract the symbol offset to get it.
259 int64_t RealOffset = GOTAddr + Addend - SymOffset - FinalAddress;
260 assert(RealOffset <= INT32_MAX && RealOffset >= INT32_MIN);
261 int32_t TruncOffset = (RealOffset & 0xFFFFFFFF);
262 *Target = TruncOffset;
265 case ELF::R_X86_64_PC32: {
266 // Get the placeholder value from the generated object since
267 // a previous relocation attempt may have overwritten the loaded version
268 uint32_t *Placeholder = reinterpret_cast<uint32_t*>(Section.ObjAddress
270 uint32_t *Target = reinterpret_cast<uint32_t*>(Section.Address + Offset);
271 uint64_t FinalAddress = Section.LoadAddress + Offset;
272 int64_t RealOffset = *Placeholder + Value + Addend - FinalAddress;
273 assert(RealOffset <= INT32_MAX && RealOffset >= INT32_MIN);
274 int32_t TruncOffset = (RealOffset & 0xFFFFFFFF);
275 *Target = TruncOffset;
278 case ELF::R_X86_64_PC64: {
279 // Get the placeholder value from the generated object since
280 // a previous relocation attempt may have overwritten the loaded version
281 uint64_t *Placeholder = reinterpret_cast<uint64_t*>(Section.ObjAddress
283 uint64_t *Target = reinterpret_cast<uint64_t*>(Section.Address + Offset);
284 uint64_t FinalAddress = Section.LoadAddress + Offset;
285 *Target = *Placeholder + Value + Addend - FinalAddress;
291 void RuntimeDyldELF::resolveX86Relocation(const SectionEntry &Section,
297 case ELF::R_386_32: {
298 // Get the placeholder value from the generated object since
299 // a previous relocation attempt may have overwritten the loaded version
300 uint32_t *Placeholder = reinterpret_cast<uint32_t*>(Section.ObjAddress
302 uint32_t *Target = reinterpret_cast<uint32_t*>(Section.Address + Offset);
303 *Target = *Placeholder + Value + Addend;
306 case ELF::R_386_PC32: {
307 // Get the placeholder value from the generated object since
308 // a previous relocation attempt may have overwritten the loaded version
309 uint32_t *Placeholder = reinterpret_cast<uint32_t*>(Section.ObjAddress
311 uint32_t *Target = reinterpret_cast<uint32_t*>(Section.Address + Offset);
312 uint32_t FinalAddress = ((Section.LoadAddress + Offset) & 0xFFFFFFFF);
313 uint32_t RealOffset = *Placeholder + Value + Addend - FinalAddress;
314 *Target = RealOffset;
318 // There are other relocation types, but it appears these are the
319 // only ones currently used by the LLVM ELF object writer
320 llvm_unreachable("Relocation type not implemented yet!");
325 void RuntimeDyldELF::resolveAArch64Relocation(const SectionEntry &Section,
330 uint32_t *TargetPtr = reinterpret_cast<uint32_t*>(Section.Address + Offset);
331 uint64_t FinalAddress = Section.LoadAddress + Offset;
333 DEBUG(dbgs() << "resolveAArch64Relocation, LocalAddress: 0x"
334 << format("%llx", Section.Address + Offset)
335 << " FinalAddress: 0x" << format("%llx",FinalAddress)
336 << " Value: 0x" << format("%llx",Value)
337 << " Type: 0x" << format("%x",Type)
338 << " Addend: 0x" << format("%llx",Addend)
343 llvm_unreachable("Relocation type not implemented yet!");
345 case ELF::R_AARCH64_ABS64: {
346 uint64_t *TargetPtr = reinterpret_cast<uint64_t*>(Section.Address + Offset);
347 *TargetPtr = Value + Addend;
350 case ELF::R_AARCH64_PREL32: {
351 uint64_t Result = Value + Addend - FinalAddress;
352 assert(static_cast<int64_t>(Result) >= INT32_MIN &&
353 static_cast<int64_t>(Result) <= UINT32_MAX);
354 *TargetPtr = static_cast<uint32_t>(Result & 0xffffffffU);
357 case ELF::R_AARCH64_CALL26: // fallthrough
358 case ELF::R_AARCH64_JUMP26: {
359 // Operation: S+A-P. Set Call or B immediate value to bits fff_fffc of the
361 uint64_t BranchImm = Value + Addend - FinalAddress;
363 // "Check that -2^27 <= result < 2^27".
364 assert(-(1LL << 27) <= static_cast<int64_t>(BranchImm) &&
365 static_cast<int64_t>(BranchImm) < (1LL << 27));
367 // AArch64 code is emitted with .rela relocations. The data already in any
368 // bits affected by the relocation on entry is garbage.
369 *TargetPtr &= 0xfc000000U;
370 // Immediate goes in bits 25:0 of B and BL.
371 *TargetPtr |= static_cast<uint32_t>(BranchImm & 0xffffffcU) >> 2;
374 case ELF::R_AARCH64_MOVW_UABS_G3: {
375 uint64_t Result = Value + Addend;
377 // AArch64 code is emitted with .rela relocations. The data already in any
378 // bits affected by the relocation on entry is garbage.
379 *TargetPtr &= 0xffe0001fU;
380 // Immediate goes in bits 20:5 of MOVZ/MOVK instruction
381 *TargetPtr |= Result >> (48 - 5);
382 // Shift must be "lsl #48", in bits 22:21
383 assert((*TargetPtr >> 21 & 0x3) == 3 && "invalid shift for relocation");
386 case ELF::R_AARCH64_MOVW_UABS_G2_NC: {
387 uint64_t Result = Value + Addend;
389 // AArch64 code is emitted with .rela relocations. The data already in any
390 // bits affected by the relocation on entry is garbage.
391 *TargetPtr &= 0xffe0001fU;
392 // Immediate goes in bits 20:5 of MOVZ/MOVK instruction
393 *TargetPtr |= ((Result & 0xffff00000000ULL) >> (32 - 5));
394 // Shift must be "lsl #32", in bits 22:21
395 assert((*TargetPtr >> 21 & 0x3) == 2 && "invalid shift for relocation");
398 case ELF::R_AARCH64_MOVW_UABS_G1_NC: {
399 uint64_t Result = Value + Addend;
401 // AArch64 code is emitted with .rela relocations. The data already in any
402 // bits affected by the relocation on entry is garbage.
403 *TargetPtr &= 0xffe0001fU;
404 // Immediate goes in bits 20:5 of MOVZ/MOVK instruction
405 *TargetPtr |= ((Result & 0xffff0000U) >> (16 - 5));
406 // Shift must be "lsl #16", in bits 22:2
407 assert((*TargetPtr >> 21 & 0x3) == 1 && "invalid shift for relocation");
410 case ELF::R_AARCH64_MOVW_UABS_G0_NC: {
411 uint64_t Result = Value + Addend;
413 // AArch64 code is emitted with .rela relocations. The data already in any
414 // bits affected by the relocation on entry is garbage.
415 *TargetPtr &= 0xffe0001fU;
416 // Immediate goes in bits 20:5 of MOVZ/MOVK instruction
417 *TargetPtr |= ((Result & 0xffffU) << 5);
418 // Shift must be "lsl #0", in bits 22:21.
419 assert((*TargetPtr >> 21 & 0x3) == 0 && "invalid shift for relocation");
425 void RuntimeDyldELF::resolveARMRelocation(const SectionEntry &Section,
430 // TODO: Add Thumb relocations.
431 uint32_t *Placeholder = reinterpret_cast<uint32_t*>(Section.ObjAddress +
433 uint32_t* TargetPtr = (uint32_t*)(Section.Address + Offset);
434 uint32_t FinalAddress = ((Section.LoadAddress + Offset) & 0xFFFFFFFF);
437 DEBUG(dbgs() << "resolveARMRelocation, LocalAddress: "
438 << Section.Address + Offset
439 << " FinalAddress: " << format("%p",FinalAddress)
440 << " Value: " << format("%x",Value)
441 << " Type: " << format("%x",Type)
442 << " Addend: " << format("%x",Addend)
447 llvm_unreachable("Not implemented relocation type!");
449 // Write a 32bit value to relocation address, taking into account the
450 // implicit addend encoded in the target.
451 case ELF::R_ARM_TARGET1:
452 case ELF::R_ARM_ABS32:
453 *TargetPtr = *Placeholder + Value;
455 // Write first 16 bit of 32 bit value to the mov instruction.
456 // Last 4 bit should be shifted.
457 case ELF::R_ARM_MOVW_ABS_NC:
458 // We are not expecting any other addend in the relocation address.
459 // Using 0x000F0FFF because MOVW has its 16 bit immediate split into 2
460 // non-contiguous fields.
461 assert((*Placeholder & 0x000F0FFF) == 0);
462 Value = Value & 0xFFFF;
463 *TargetPtr = *Placeholder | (Value & 0xFFF);
464 *TargetPtr |= ((Value >> 12) & 0xF) << 16;
466 // Write last 16 bit of 32 bit value to the mov instruction.
467 // Last 4 bit should be shifted.
468 case ELF::R_ARM_MOVT_ABS:
469 // We are not expecting any other addend in the relocation address.
470 // Use 0x000F0FFF for the same reason as R_ARM_MOVW_ABS_NC.
471 assert((*Placeholder & 0x000F0FFF) == 0);
473 Value = (Value >> 16) & 0xFFFF;
474 *TargetPtr = *Placeholder | (Value & 0xFFF);
475 *TargetPtr |= ((Value >> 12) & 0xF) << 16;
477 // Write 24 bit relative value to the branch instruction.
478 case ELF::R_ARM_PC24 : // Fall through.
479 case ELF::R_ARM_CALL : // Fall through.
480 case ELF::R_ARM_JUMP24: {
481 int32_t RelValue = static_cast<int32_t>(Value - FinalAddress - 8);
482 RelValue = (RelValue & 0x03FFFFFC) >> 2;
483 assert((*TargetPtr & 0xFFFFFF) == 0xFFFFFE);
484 *TargetPtr &= 0xFF000000;
485 *TargetPtr |= RelValue;
488 case ELF::R_ARM_PRIVATE_0:
489 // This relocation is reserved by the ARM ELF ABI for internal use. We
490 // appropriate it here to act as an R_ARM_ABS32 without any addend for use
491 // in the stubs created during JIT (which can't put an addend into the
492 // original object file).
498 void RuntimeDyldELF::resolveMIPSRelocation(const SectionEntry &Section,
503 uint32_t *Placeholder = reinterpret_cast<uint32_t*>(Section.ObjAddress +
505 uint32_t* TargetPtr = (uint32_t*)(Section.Address + Offset);
508 DEBUG(dbgs() << "resolveMipselocation, LocalAddress: "
509 << Section.Address + Offset
511 << format("%p",Section.LoadAddress + Offset)
512 << " Value: " << format("%x",Value)
513 << " Type: " << format("%x",Type)
514 << " Addend: " << format("%x",Addend)
519 llvm_unreachable("Not implemented relocation type!");
522 *TargetPtr = Value + (*Placeholder);
525 *TargetPtr = ((*Placeholder) & 0xfc000000) | (( Value & 0x0fffffff) >> 2);
527 case ELF::R_MIPS_HI16:
528 // Get the higher 16-bits. Also add 1 if bit 15 is 1.
529 Value += ((*Placeholder) & 0x0000ffff) << 16;
530 *TargetPtr = ((*Placeholder) & 0xffff0000) |
531 (((Value + 0x8000) >> 16) & 0xffff);
533 case ELF::R_MIPS_LO16:
534 Value += ((*Placeholder) & 0x0000ffff);
535 *TargetPtr = ((*Placeholder) & 0xffff0000) | (Value & 0xffff);
537 case ELF::R_MIPS_UNUSED1:
538 // Similar to ELF::R_ARM_PRIVATE_0, R_MIPS_UNUSED1 and R_MIPS_UNUSED2
539 // are used for internal JIT purpose. These relocations are similar to
540 // R_MIPS_HI16 and R_MIPS_LO16, but they do not take any addend into
542 *TargetPtr = ((*TargetPtr) & 0xffff0000) |
543 (((Value + 0x8000) >> 16) & 0xffff);
545 case ELF::R_MIPS_UNUSED2:
546 *TargetPtr = ((*TargetPtr) & 0xffff0000) | (Value & 0xffff);
551 // Return the .TOC. section address to R_PPC64_TOC relocations.
552 uint64_t RuntimeDyldELF::findPPC64TOC() const {
553 // The TOC consists of sections .got, .toc, .tocbss, .plt in that
554 // order. The TOC starts where the first of these sections starts.
555 SectionList::const_iterator it = Sections.begin();
556 SectionList::const_iterator ite = Sections.end();
557 for (; it != ite; ++it) {
558 if (it->Name == ".got" ||
559 it->Name == ".toc" ||
560 it->Name == ".tocbss" ||
565 // This may happen for
566 // * references to TOC base base (sym@toc, .odp relocation) without
568 // In this case just use the first section (which is usually
569 // the .odp) since the code won't reference the .toc base
571 it = Sections.begin();
574 // Per the ppc64-elf-linux ABI, The TOC base is TOC value plus 0x8000
575 // thus permitting a full 64 Kbytes segment.
576 return it->LoadAddress + 0x8000;
579 // Returns the sections and offset associated with the ODP entry referenced
581 void RuntimeDyldELF::findOPDEntrySection(ObjectImage &Obj,
582 ObjSectionToIDMap &LocalSections,
583 RelocationValueRef &Rel) {
584 // Get the ELF symbol value (st_value) to compare with Relocation offset in
588 for (section_iterator si = Obj.begin_sections(),
589 se = Obj.end_sections(); si != se; si.increment(err)) {
590 section_iterator RelSecI = si->getRelocatedSection();
591 if (RelSecI == Obj.end_sections())
594 StringRef RelSectionName;
595 check(RelSecI->getName(RelSectionName));
596 if (RelSectionName != ".opd")
599 for (relocation_iterator i = si->begin_relocations(),
600 e = si->end_relocations(); i != e;) {
603 // The R_PPC64_ADDR64 relocation indicates the first field
606 check(i->getType(TypeFunc));
607 if (TypeFunc != ELF::R_PPC64_ADDR64) {
612 uint64_t TargetSymbolOffset;
613 symbol_iterator TargetSymbol = i->getSymbol();
614 check(i->getOffset(TargetSymbolOffset));
616 check(getELFRelocationAddend(*i, Addend));
618 i = i.increment(err);
623 // Just check if following relocation is a R_PPC64_TOC
625 check(i->getType(TypeTOC));
626 if (TypeTOC != ELF::R_PPC64_TOC)
629 // Finally compares the Symbol value and the target symbol offset
630 // to check if this .opd entry refers to the symbol the relocation
632 if (Rel.Addend != (int64_t)TargetSymbolOffset)
635 section_iterator tsi(Obj.end_sections());
636 check(TargetSymbol->getSection(tsi));
637 Rel.SectionID = findOrEmitSection(Obj, (*tsi), true, LocalSections);
638 Rel.Addend = (intptr_t)Addend;
642 llvm_unreachable("Attempting to get address of ODP entry!");
645 // Relocation masks following the #lo(value), #hi(value), #higher(value),
646 // and #highest(value) macros defined in section 4.5.1. Relocation Types
647 // in PPC-elf64abi document.
650 uint16_t applyPPClo (uint64_t value)
652 return value & 0xffff;
656 uint16_t applyPPChi (uint64_t value)
658 return (value >> 16) & 0xffff;
662 uint16_t applyPPChigher (uint64_t value)
664 return (value >> 32) & 0xffff;
668 uint16_t applyPPChighest (uint64_t value)
670 return (value >> 48) & 0xffff;
673 void RuntimeDyldELF::resolvePPC64Relocation(const SectionEntry &Section,
678 uint8_t* LocalAddress = Section.Address + Offset;
681 llvm_unreachable("Relocation type not implemented yet!");
683 case ELF::R_PPC64_ADDR16_LO :
684 writeInt16BE(LocalAddress, applyPPClo (Value + Addend));
686 case ELF::R_PPC64_ADDR16_HI :
687 writeInt16BE(LocalAddress, applyPPChi (Value + Addend));
689 case ELF::R_PPC64_ADDR16_HIGHER :
690 writeInt16BE(LocalAddress, applyPPChigher (Value + Addend));
692 case ELF::R_PPC64_ADDR16_HIGHEST :
693 writeInt16BE(LocalAddress, applyPPChighest (Value + Addend));
695 case ELF::R_PPC64_ADDR14 : {
696 assert(((Value + Addend) & 3) == 0);
697 // Preserve the AA/LK bits in the branch instruction
698 uint8_t aalk = *(LocalAddress+3);
699 writeInt16BE(LocalAddress + 2, (aalk & 3) | ((Value + Addend) & 0xfffc));
701 case ELF::R_PPC64_ADDR32 : {
702 int32_t Result = static_cast<int32_t>(Value + Addend);
703 if (SignExtend32<32>(Result) != Result)
704 llvm_unreachable("Relocation R_PPC64_ADDR32 overflow");
705 writeInt32BE(LocalAddress, Result);
707 case ELF::R_PPC64_REL24 : {
708 uint64_t FinalAddress = (Section.LoadAddress + Offset);
709 int32_t delta = static_cast<int32_t>(Value - FinalAddress + Addend);
710 if (SignExtend32<24>(delta) != delta)
711 llvm_unreachable("Relocation R_PPC64_REL24 overflow");
712 // Generates a 'bl <address>' instruction
713 writeInt32BE(LocalAddress, 0x48000001 | (delta & 0x03FFFFFC));
715 case ELF::R_PPC64_REL32 : {
716 uint64_t FinalAddress = (Section.LoadAddress + Offset);
717 int32_t delta = static_cast<int32_t>(Value - FinalAddress + Addend);
718 if (SignExtend32<32>(delta) != delta)
719 llvm_unreachable("Relocation R_PPC64_REL32 overflow");
720 writeInt32BE(LocalAddress, delta);
722 case ELF::R_PPC64_REL64: {
723 uint64_t FinalAddress = (Section.LoadAddress + Offset);
724 uint64_t Delta = Value - FinalAddress + Addend;
725 writeInt64BE(LocalAddress, Delta);
727 case ELF::R_PPC64_ADDR64 :
728 writeInt64BE(LocalAddress, Value + Addend);
730 case ELF::R_PPC64_TOC :
731 writeInt64BE(LocalAddress, findPPC64TOC());
733 case ELF::R_PPC64_TOC16 : {
734 uint64_t TOCStart = findPPC64TOC();
735 Value = applyPPClo((Value + Addend) - TOCStart);
736 writeInt16BE(LocalAddress, applyPPClo(Value));
738 case ELF::R_PPC64_TOC16_DS : {
739 uint64_t TOCStart = findPPC64TOC();
740 Value = ((Value + Addend) - TOCStart);
741 writeInt16BE(LocalAddress, applyPPClo(Value));
746 void RuntimeDyldELF::resolveSystemZRelocation(const SectionEntry &Section,
751 uint8_t *LocalAddress = Section.Address + Offset;
754 llvm_unreachable("Relocation type not implemented yet!");
756 case ELF::R_390_PC16DBL:
757 case ELF::R_390_PLT16DBL: {
758 int64_t Delta = (Value + Addend) - (Section.LoadAddress + Offset);
759 assert(int16_t(Delta / 2) * 2 == Delta && "R_390_PC16DBL overflow");
760 writeInt16BE(LocalAddress, Delta / 2);
763 case ELF::R_390_PC32DBL:
764 case ELF::R_390_PLT32DBL: {
765 int64_t Delta = (Value + Addend) - (Section.LoadAddress + Offset);
766 assert(int32_t(Delta / 2) * 2 == Delta && "R_390_PC32DBL overflow");
767 writeInt32BE(LocalAddress, Delta / 2);
770 case ELF::R_390_PC32: {
771 int64_t Delta = (Value + Addend) - (Section.LoadAddress + Offset);
772 assert(int32_t(Delta) == Delta && "R_390_PC32 overflow");
773 writeInt32BE(LocalAddress, Delta);
777 writeInt64BE(LocalAddress, Value + Addend);
782 // The target location for the relocation is described by RE.SectionID and
783 // RE.Offset. RE.SectionID can be used to find the SectionEntry. Each
784 // SectionEntry has three members describing its location.
785 // SectionEntry::Address is the address at which the section has been loaded
786 // into memory in the current (host) process. SectionEntry::LoadAddress is the
787 // address that the section will have in the target process.
788 // SectionEntry::ObjAddress is the address of the bits for this section in the
789 // original emitted object image (also in the current address space).
791 // Relocations will be applied as if the section were loaded at
792 // SectionEntry::LoadAddress, but they will be applied at an address based
793 // on SectionEntry::Address. SectionEntry::ObjAddress will be used to refer to
794 // Target memory contents if they are required for value calculations.
796 // The Value parameter here is the load address of the symbol for the
797 // relocation to be applied. For relocations which refer to symbols in the
798 // current object Value will be the LoadAddress of the section in which
799 // the symbol resides (RE.Addend provides additional information about the
800 // symbol location). For external symbols, Value will be the address of the
801 // symbol in the target address space.
802 void RuntimeDyldELF::resolveRelocation(const RelocationEntry &RE,
804 const SectionEntry &Section = Sections[RE.SectionID];
805 return resolveRelocation(Section, RE.Offset, Value, RE.RelType, RE.Addend,
809 void RuntimeDyldELF::resolveRelocation(const SectionEntry &Section,
814 uint64_t SymOffset) {
817 resolveX86_64Relocation(Section, Offset, Value, Type, Addend, SymOffset);
820 resolveX86Relocation(Section, Offset,
821 (uint32_t)(Value & 0xffffffffL), Type,
822 (uint32_t)(Addend & 0xffffffffL));
824 case Triple::aarch64:
825 resolveAArch64Relocation(Section, Offset, Value, Type, Addend);
827 case Triple::arm: // Fall through.
829 resolveARMRelocation(Section, Offset,
830 (uint32_t)(Value & 0xffffffffL), Type,
831 (uint32_t)(Addend & 0xffffffffL));
833 case Triple::mips: // Fall through.
835 resolveMIPSRelocation(Section, Offset,
836 (uint32_t)(Value & 0xffffffffL), Type,
837 (uint32_t)(Addend & 0xffffffffL));
839 case Triple::ppc64: // Fall through.
840 case Triple::ppc64le:
841 resolvePPC64Relocation(Section, Offset, Value, Type, Addend);
843 case Triple::systemz:
844 resolveSystemZRelocation(Section, Offset, Value, Type, Addend);
846 default: llvm_unreachable("Unsupported CPU type!");
850 void RuntimeDyldELF::processRelocationRef(unsigned SectionID,
853 ObjSectionToIDMap &ObjSectionToID,
854 const SymbolTableMap &Symbols,
857 Check(RelI.getType(RelType));
859 Check(getELFRelocationAddend(RelI, Addend));
860 symbol_iterator Symbol = RelI.getSymbol();
862 // Obtain the symbol name which is referenced in the relocation
863 StringRef TargetName;
864 if (Symbol != Obj.end_symbols())
865 Symbol->getName(TargetName);
866 DEBUG(dbgs() << "\t\tRelType: " << RelType
867 << " Addend: " << Addend
868 << " TargetName: " << TargetName
870 RelocationValueRef Value;
871 // First search for the symbol in the local symbol table
872 SymbolTableMap::const_iterator lsi = Symbols.end();
873 SymbolRef::Type SymType = SymbolRef::ST_Unknown;
874 if (Symbol != Obj.end_symbols()) {
875 lsi = Symbols.find(TargetName.data());
876 Symbol->getType(SymType);
878 if (lsi != Symbols.end()) {
879 Value.SectionID = lsi->second.first;
880 Value.Offset = lsi->second.second;
881 Value.Addend = lsi->second.second + Addend;
883 // Search for the symbol in the global symbol table
884 SymbolTableMap::const_iterator gsi = GlobalSymbolTable.end();
885 if (Symbol != Obj.end_symbols())
886 gsi = GlobalSymbolTable.find(TargetName.data());
887 if (gsi != GlobalSymbolTable.end()) {
888 Value.SectionID = gsi->second.first;
889 Value.Offset = gsi->second.second;
890 Value.Addend = gsi->second.second + Addend;
893 case SymbolRef::ST_Debug: {
894 // TODO: Now ELF SymbolRef::ST_Debug = STT_SECTION, it's not obviously
895 // and can be changed by another developers. Maybe best way is add
896 // a new symbol type ST_Section to SymbolRef and use it.
897 section_iterator si(Obj.end_sections());
898 Symbol->getSection(si);
899 if (si == Obj.end_sections())
900 llvm_unreachable("Symbol section not found, bad object file format!");
901 DEBUG(dbgs() << "\t\tThis is section symbol\n");
902 // Default to 'true' in case isText fails (though it never does).
905 Value.SectionID = findOrEmitSection(Obj,
909 Value.Addend = Addend;
912 case SymbolRef::ST_Data:
913 case SymbolRef::ST_Unknown: {
914 Value.SymbolName = TargetName.data();
915 Value.Addend = Addend;
917 // Absolute relocations will have a zero symbol ID (STN_UNDEF), which
918 // will manifest here as a NULL symbol name.
919 // We can set this as a valid (but empty) symbol name, and rely
920 // on addRelocationForSymbol to handle this.
921 if (!Value.SymbolName)
922 Value.SymbolName = "";
926 llvm_unreachable("Unresolved symbol type!");
932 Check(RelI.getOffset(Offset));
934 DEBUG(dbgs() << "\t\tSectionID: " << SectionID
935 << " Offset: " << Offset
937 if (Arch == Triple::aarch64 &&
938 (RelType == ELF::R_AARCH64_CALL26 ||
939 RelType == ELF::R_AARCH64_JUMP26)) {
940 // This is an AArch64 branch relocation, need to use a stub function.
941 DEBUG(dbgs() << "\t\tThis is an AArch64 branch relocation.");
942 SectionEntry &Section = Sections[SectionID];
944 // Look for an existing stub.
945 StubMap::const_iterator i = Stubs.find(Value);
946 if (i != Stubs.end()) {
947 resolveRelocation(Section, Offset,
948 (uint64_t)Section.Address + i->second, RelType, 0);
949 DEBUG(dbgs() << " Stub function found\n");
951 // Create a new stub function.
952 DEBUG(dbgs() << " Create a new stub function\n");
953 Stubs[Value] = Section.StubOffset;
954 uint8_t *StubTargetAddr = createStubFunction(Section.Address +
957 RelocationEntry REmovz_g3(SectionID,
958 StubTargetAddr - Section.Address,
959 ELF::R_AARCH64_MOVW_UABS_G3, Value.Addend);
960 RelocationEntry REmovk_g2(SectionID,
961 StubTargetAddr - Section.Address + 4,
962 ELF::R_AARCH64_MOVW_UABS_G2_NC, Value.Addend);
963 RelocationEntry REmovk_g1(SectionID,
964 StubTargetAddr - Section.Address + 8,
965 ELF::R_AARCH64_MOVW_UABS_G1_NC, Value.Addend);
966 RelocationEntry REmovk_g0(SectionID,
967 StubTargetAddr - Section.Address + 12,
968 ELF::R_AARCH64_MOVW_UABS_G0_NC, Value.Addend);
970 if (Value.SymbolName) {
971 addRelocationForSymbol(REmovz_g3, Value.SymbolName);
972 addRelocationForSymbol(REmovk_g2, Value.SymbolName);
973 addRelocationForSymbol(REmovk_g1, Value.SymbolName);
974 addRelocationForSymbol(REmovk_g0, Value.SymbolName);
976 addRelocationForSection(REmovz_g3, Value.SectionID);
977 addRelocationForSection(REmovk_g2, Value.SectionID);
978 addRelocationForSection(REmovk_g1, Value.SectionID);
979 addRelocationForSection(REmovk_g0, Value.SectionID);
981 resolveRelocation(Section, Offset,
982 (uint64_t)Section.Address + Section.StubOffset,
984 Section.StubOffset += getMaxStubSize();
986 } else if (Arch == Triple::arm &&
987 (RelType == ELF::R_ARM_PC24 ||
988 RelType == ELF::R_ARM_CALL ||
989 RelType == ELF::R_ARM_JUMP24)) {
990 // This is an ARM branch relocation, need to use a stub function.
991 DEBUG(dbgs() << "\t\tThis is an ARM branch relocation.");
992 SectionEntry &Section = Sections[SectionID];
994 // Look for an existing stub.
995 StubMap::const_iterator i = Stubs.find(Value);
996 if (i != Stubs.end()) {
997 resolveRelocation(Section, Offset,
998 (uint64_t)Section.Address + i->second, RelType, 0);
999 DEBUG(dbgs() << " Stub function found\n");
1001 // Create a new stub function.
1002 DEBUG(dbgs() << " Create a new stub function\n");
1003 Stubs[Value] = Section.StubOffset;
1004 uint8_t *StubTargetAddr = createStubFunction(Section.Address +
1005 Section.StubOffset);
1006 RelocationEntry RE(SectionID, StubTargetAddr - Section.Address,
1007 ELF::R_ARM_PRIVATE_0, Value.Addend);
1008 if (Value.SymbolName)
1009 addRelocationForSymbol(RE, Value.SymbolName);
1011 addRelocationForSection(RE, Value.SectionID);
1013 resolveRelocation(Section, Offset,
1014 (uint64_t)Section.Address + Section.StubOffset,
1016 Section.StubOffset += getMaxStubSize();
1018 } else if ((Arch == Triple::mipsel || Arch == Triple::mips) &&
1019 RelType == ELF::R_MIPS_26) {
1020 // This is an Mips branch relocation, need to use a stub function.
1021 DEBUG(dbgs() << "\t\tThis is a Mips branch relocation.");
1022 SectionEntry &Section = Sections[SectionID];
1023 uint8_t *Target = Section.Address + Offset;
1024 uint32_t *TargetAddress = (uint32_t *)Target;
1026 // Extract the addend from the instruction.
1027 uint32_t Addend = ((*TargetAddress) & 0x03ffffff) << 2;
1029 Value.Addend += Addend;
1031 // Look up for existing stub.
1032 StubMap::const_iterator i = Stubs.find(Value);
1033 if (i != Stubs.end()) {
1034 RelocationEntry RE(SectionID, Offset, RelType, i->second);
1035 addRelocationForSection(RE, SectionID);
1036 DEBUG(dbgs() << " Stub function found\n");
1038 // Create a new stub function.
1039 DEBUG(dbgs() << " Create a new stub function\n");
1040 Stubs[Value] = Section.StubOffset;
1041 uint8_t *StubTargetAddr = createStubFunction(Section.Address +
1042 Section.StubOffset);
1044 // Creating Hi and Lo relocations for the filled stub instructions.
1045 RelocationEntry REHi(SectionID,
1046 StubTargetAddr - Section.Address,
1047 ELF::R_MIPS_UNUSED1, Value.Addend);
1048 RelocationEntry RELo(SectionID,
1049 StubTargetAddr - Section.Address + 4,
1050 ELF::R_MIPS_UNUSED2, Value.Addend);
1052 if (Value.SymbolName) {
1053 addRelocationForSymbol(REHi, Value.SymbolName);
1054 addRelocationForSymbol(RELo, Value.SymbolName);
1056 addRelocationForSection(REHi, Value.SectionID);
1057 addRelocationForSection(RELo, Value.SectionID);
1060 RelocationEntry RE(SectionID, Offset, RelType, Section.StubOffset);
1061 addRelocationForSection(RE, SectionID);
1062 Section.StubOffset += getMaxStubSize();
1064 } else if (Arch == Triple::ppc64 || Arch == Triple::ppc64le) {
1065 if (RelType == ELF::R_PPC64_REL24) {
1066 // A PPC branch relocation will need a stub function if the target is
1067 // an external symbol (Symbol::ST_Unknown) or if the target address
1068 // is not within the signed 24-bits branch address.
1069 SectionEntry &Section = Sections[SectionID];
1070 uint8_t *Target = Section.Address + Offset;
1071 bool RangeOverflow = false;
1072 if (SymType != SymbolRef::ST_Unknown) {
1073 // A function call may points to the .opd entry, so the final symbol value
1074 // in calculated based in the relocation values in .opd section.
1075 findOPDEntrySection(Obj, ObjSectionToID, Value);
1076 uint8_t *RelocTarget = Sections[Value.SectionID].Address + Value.Addend;
1077 int32_t delta = static_cast<int32_t>(Target - RelocTarget);
1078 // If it is within 24-bits branch range, just set the branch target
1079 if (SignExtend32<24>(delta) == delta) {
1080 RelocationEntry RE(SectionID, Offset, RelType, Value.Addend);
1081 if (Value.SymbolName)
1082 addRelocationForSymbol(RE, Value.SymbolName);
1084 addRelocationForSection(RE, Value.SectionID);
1086 RangeOverflow = true;
1089 if (SymType == SymbolRef::ST_Unknown || RangeOverflow == true) {
1090 // It is an external symbol (SymbolRef::ST_Unknown) or within a range
1091 // larger than 24-bits.
1092 StubMap::const_iterator i = Stubs.find(Value);
1093 if (i != Stubs.end()) {
1094 // Symbol function stub already created, just relocate to it
1095 resolveRelocation(Section, Offset,
1096 (uint64_t)Section.Address + i->second, RelType, 0);
1097 DEBUG(dbgs() << " Stub function found\n");
1099 // Create a new stub function.
1100 DEBUG(dbgs() << " Create a new stub function\n");
1101 Stubs[Value] = Section.StubOffset;
1102 uint8_t *StubTargetAddr = createStubFunction(Section.Address +
1103 Section.StubOffset);
1104 RelocationEntry RE(SectionID, StubTargetAddr - Section.Address,
1105 ELF::R_PPC64_ADDR64, Value.Addend);
1107 // Generates the 64-bits address loads as exemplified in section
1108 // 4.5.1 in PPC64 ELF ABI.
1109 RelocationEntry REhst(SectionID,
1110 StubTargetAddr - Section.Address + 2,
1111 ELF::R_PPC64_ADDR16_HIGHEST, Value.Addend);
1112 RelocationEntry REhr(SectionID,
1113 StubTargetAddr - Section.Address + 6,
1114 ELF::R_PPC64_ADDR16_HIGHER, Value.Addend);
1115 RelocationEntry REh(SectionID,
1116 StubTargetAddr - Section.Address + 14,
1117 ELF::R_PPC64_ADDR16_HI, Value.Addend);
1118 RelocationEntry REl(SectionID,
1119 StubTargetAddr - Section.Address + 18,
1120 ELF::R_PPC64_ADDR16_LO, Value.Addend);
1122 if (Value.SymbolName) {
1123 addRelocationForSymbol(REhst, Value.SymbolName);
1124 addRelocationForSymbol(REhr, Value.SymbolName);
1125 addRelocationForSymbol(REh, Value.SymbolName);
1126 addRelocationForSymbol(REl, Value.SymbolName);
1128 addRelocationForSection(REhst, Value.SectionID);
1129 addRelocationForSection(REhr, Value.SectionID);
1130 addRelocationForSection(REh, Value.SectionID);
1131 addRelocationForSection(REl, Value.SectionID);
1134 resolveRelocation(Section, Offset,
1135 (uint64_t)Section.Address + Section.StubOffset,
1137 if (SymType == SymbolRef::ST_Unknown)
1138 // Restore the TOC for external calls
1139 writeInt32BE(Target+4, 0xE8410028); // ld r2,40(r1)
1140 Section.StubOffset += getMaxStubSize();
1144 RelocationEntry RE(SectionID, Offset, RelType, Value.Addend);
1145 // Extra check to avoid relocation againt empty symbols (usually
1146 // the R_PPC64_TOC).
1147 if (SymType != SymbolRef::ST_Unknown && TargetName.empty())
1148 Value.SymbolName = NULL;
1150 if (Value.SymbolName)
1151 addRelocationForSymbol(RE, Value.SymbolName);
1153 addRelocationForSection(RE, Value.SectionID);
1155 } else if (Arch == Triple::systemz &&
1156 (RelType == ELF::R_390_PLT32DBL ||
1157 RelType == ELF::R_390_GOTENT)) {
1158 // Create function stubs for both PLT and GOT references, regardless of
1159 // whether the GOT reference is to data or code. The stub contains the
1160 // full address of the symbol, as needed by GOT references, and the
1161 // executable part only adds an overhead of 8 bytes.
1163 // We could try to conserve space by allocating the code and data
1164 // parts of the stub separately. However, as things stand, we allocate
1165 // a stub for every relocation, so using a GOT in JIT code should be
1166 // no less space efficient than using an explicit constant pool.
1167 DEBUG(dbgs() << "\t\tThis is a SystemZ indirect relocation.");
1168 SectionEntry &Section = Sections[SectionID];
1170 // Look for an existing stub.
1171 StubMap::const_iterator i = Stubs.find(Value);
1172 uintptr_t StubAddress;
1173 if (i != Stubs.end()) {
1174 StubAddress = uintptr_t(Section.Address) + i->second;
1175 DEBUG(dbgs() << " Stub function found\n");
1177 // Create a new stub function.
1178 DEBUG(dbgs() << " Create a new stub function\n");
1180 uintptr_t BaseAddress = uintptr_t(Section.Address);
1181 uintptr_t StubAlignment = getStubAlignment();
1182 StubAddress = (BaseAddress + Section.StubOffset +
1183 StubAlignment - 1) & -StubAlignment;
1184 unsigned StubOffset = StubAddress - BaseAddress;
1186 Stubs[Value] = StubOffset;
1187 createStubFunction((uint8_t *)StubAddress);
1188 RelocationEntry RE(SectionID, StubOffset + 8,
1189 ELF::R_390_64, Value.Addend - Addend);
1190 if (Value.SymbolName)
1191 addRelocationForSymbol(RE, Value.SymbolName);
1193 addRelocationForSection(RE, Value.SectionID);
1194 Section.StubOffset = StubOffset + getMaxStubSize();
1197 if (RelType == ELF::R_390_GOTENT)
1198 resolveRelocation(Section, Offset, StubAddress + 8,
1199 ELF::R_390_PC32DBL, Addend);
1201 resolveRelocation(Section, Offset, StubAddress, RelType, Addend);
1202 } else if (Arch == Triple::x86_64 && RelType == ELF::R_X86_64_PLT32) {
1203 // The way the PLT relocations normally work is that the linker allocates the
1204 // PLT and this relocation makes a PC-relative call into the PLT. The PLT
1205 // entry will then jump to an address provided by the GOT. On first call, the
1206 // GOT address will point back into PLT code that resolves the symbol. After
1207 // the first call, the GOT entry points to the actual function.
1209 // For local functions we're ignoring all of that here and just replacing
1210 // the PLT32 relocation type with PC32, which will translate the relocation
1211 // into a PC-relative call directly to the function. For external symbols we
1212 // can't be sure the function will be within 2^32 bytes of the call site, so
1213 // we need to create a stub, which calls into the GOT. This case is
1214 // equivalent to the usual PLT implementation except that we use the stub
1215 // mechanism in RuntimeDyld (which puts stubs at the end of the section)
1216 // rather than allocating a PLT section.
1217 if (Value.SymbolName) {
1218 // This is a call to an external function.
1219 // Look for an existing stub.
1220 SectionEntry &Section = Sections[SectionID];
1221 StubMap::const_iterator i = Stubs.find(Value);
1222 uintptr_t StubAddress;
1223 if (i != Stubs.end()) {
1224 StubAddress = uintptr_t(Section.Address) + i->second;
1225 DEBUG(dbgs() << " Stub function found\n");
1227 // Create a new stub function (equivalent to a PLT entry).
1228 DEBUG(dbgs() << " Create a new stub function\n");
1230 uintptr_t BaseAddress = uintptr_t(Section.Address);
1231 uintptr_t StubAlignment = getStubAlignment();
1232 StubAddress = (BaseAddress + Section.StubOffset +
1233 StubAlignment - 1) & -StubAlignment;
1234 unsigned StubOffset = StubAddress - BaseAddress;
1235 Stubs[Value] = StubOffset;
1236 createStubFunction((uint8_t *)StubAddress);
1238 // Create a GOT entry for the external function.
1239 GOTEntries.push_back(Value);
1241 // Make our stub function a relative call to the GOT entry.
1242 RelocationEntry RE(SectionID, StubOffset + 2,
1243 ELF::R_X86_64_GOTPCREL, -4);
1244 addRelocationForSymbol(RE, Value.SymbolName);
1246 // Bump our stub offset counter
1247 Section.StubOffset = StubOffset + getMaxStubSize();
1250 // Make the target call a call into the stub table.
1251 resolveRelocation(Section, Offset, StubAddress,
1252 ELF::R_X86_64_PC32, Addend);
1254 RelocationEntry RE(SectionID, Offset, ELF::R_X86_64_PC32, Value.Addend,
1256 addRelocationForSection(RE, Value.SectionID);
1259 if (Arch == Triple::x86_64 && RelType == ELF::R_X86_64_GOTPCREL) {
1260 GOTEntries.push_back(Value);
1262 RelocationEntry RE(SectionID, Offset, RelType, Value.Addend, Value.Offset);
1263 if (Value.SymbolName)
1264 addRelocationForSymbol(RE, Value.SymbolName);
1266 addRelocationForSection(RE, Value.SectionID);
1270 void RuntimeDyldELF::updateGOTEntries(StringRef Name, uint64_t Addr) {
1272 SmallVectorImpl<std::pair<SID, GOTRelocations> >::iterator it;
1273 SmallVectorImpl<std::pair<SID, GOTRelocations> >::iterator end = GOTs.end();
1275 for (it = GOTs.begin(); it != end; ++it) {
1276 GOTRelocations &GOTEntries = it->second;
1277 for (int i = 0, e = GOTEntries.size(); i != e; ++i) {
1278 if (GOTEntries[i].SymbolName != 0 && GOTEntries[i].SymbolName == Name) {
1279 GOTEntries[i].Offset = Addr;
1285 size_t RuntimeDyldELF::getGOTEntrySize() {
1286 // We don't use the GOT in all of these cases, but it's essentially free
1287 // to put them all here.
1290 case Triple::x86_64:
1291 case Triple::aarch64:
1293 case Triple::ppc64le:
1294 case Triple::systemz:
1295 Result = sizeof(uint64_t);
1301 case Triple::mipsel:
1302 Result = sizeof(uint32_t);
1304 default: llvm_unreachable("Unsupported CPU type!");
1309 uint64_t RuntimeDyldELF::findGOTEntry(uint64_t LoadAddress,
1312 const size_t GOTEntrySize = getGOTEntrySize();
1314 SmallVectorImpl<std::pair<SID, GOTRelocations> >::const_iterator it;
1315 SmallVectorImpl<std::pair<SID, GOTRelocations> >::const_iterator end = GOTs.end();
1318 for (it = GOTs.begin(); it != end; ++it) {
1319 SID GOTSectionID = it->first;
1320 const GOTRelocations &GOTEntries = it->second;
1322 // Find the matching entry in our vector.
1323 uint64_t SymbolOffset = 0;
1324 for (int i = 0, e = GOTEntries.size(); i != e; ++i) {
1325 if (GOTEntries[i].SymbolName == 0) {
1326 if (getSectionLoadAddress(GOTEntries[i].SectionID) == LoadAddress &&
1327 GOTEntries[i].Offset == Offset) {
1329 SymbolOffset = GOTEntries[i].Offset;
1333 // GOT entries for external symbols use the addend as the address when
1334 // the external symbol has been resolved.
1335 if (GOTEntries[i].Offset == LoadAddress) {
1337 // Don't use the Addend here. The relocation handler will use it.
1343 if (GOTIndex != -1) {
1344 if (GOTEntrySize == sizeof(uint64_t)) {
1345 uint64_t *LocalGOTAddr = (uint64_t*)getSectionAddress(GOTSectionID);
1346 // Fill in this entry with the address of the symbol being referenced.
1347 LocalGOTAddr[GOTIndex] = LoadAddress + SymbolOffset;
1349 uint32_t *LocalGOTAddr = (uint32_t*)getSectionAddress(GOTSectionID);
1350 // Fill in this entry with the address of the symbol being referenced.
1351 LocalGOTAddr[GOTIndex] = (uint32_t)(LoadAddress + SymbolOffset);
1354 // Calculate the load address of this entry
1355 return getSectionLoadAddress(GOTSectionID) + (GOTIndex * GOTEntrySize);
1359 assert(GOTIndex != -1 && "Unable to find requested GOT entry.");
1363 void RuntimeDyldELF::finalizeLoad(ObjSectionToIDMap &SectionMap) {
1364 // If necessary, allocate the global offset table
1366 // Allocate the GOT if necessary
1367 size_t numGOTEntries = GOTEntries.size();
1368 if (numGOTEntries != 0) {
1369 // Allocate memory for the section
1370 unsigned SectionID = Sections.size();
1371 size_t TotalSize = numGOTEntries * getGOTEntrySize();
1372 uint8_t *Addr = MemMgr->allocateDataSection(TotalSize, getGOTEntrySize(),
1373 SectionID, ".got", false);
1375 report_fatal_error("Unable to allocate memory for GOT!");
1377 GOTs.push_back(std::make_pair(SectionID, GOTEntries));
1378 Sections.push_back(SectionEntry(".got", Addr, TotalSize, 0));
1379 // For now, initialize all GOT entries to zero. We'll fill them in as
1380 // needed when GOT-based relocations are applied.
1381 memset(Addr, 0, TotalSize);
1385 report_fatal_error("Unable to allocate memory for GOT!");
1388 // Look for and record the EH frame section.
1389 ObjSectionToIDMap::iterator i, e;
1390 for (i = SectionMap.begin(), e = SectionMap.end(); i != e; ++i) {
1391 const SectionRef &Section = i->first;
1393 Section.getName(Name);
1394 if (Name == ".eh_frame") {
1395 UnregisteredEHFrameSections.push_back(i->second);
1401 bool RuntimeDyldELF::isCompatibleFormat(const ObjectBuffer *Buffer) const {
1402 if (Buffer->getBufferSize() < strlen(ELF::ElfMagic))
1404 return (memcmp(Buffer->getBufferStart(), ELF::ElfMagic, strlen(ELF::ElfMagic))) == 0;