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: {
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));
322 // AArch64 code is emitted with .rela relocations. The data already in any
323 // bits affected by the relocation on entry is garbage.
324 *TargetPtr &= 0xfc000000U;
325 // Immediate goes in bits 25:0 of B and BL.
326 *TargetPtr |= static_cast<uint32_t>(BranchImm & 0xffffffcU) >> 2;
329 case ELF::R_AARCH64_MOVW_UABS_G3: {
330 uint64_t Result = Value + Addend;
332 // AArch64 code is emitted with .rela relocations. The data already in any
333 // bits affected by the relocation on entry is garbage.
334 *TargetPtr &= 0xff80001fU;
335 // Immediate goes in bits 20:5 of MOVZ/MOVK instruction
336 *TargetPtr |= Result >> (48 - 5);
337 // Shift is "lsl #48", in bits 22:21
338 *TargetPtr |= 3 << 21;
341 case ELF::R_AARCH64_MOVW_UABS_G2_NC: {
342 uint64_t Result = Value + Addend;
345 // AArch64 code is emitted with .rela relocations. The data already in any
346 // bits affected by the relocation on entry is garbage.
347 *TargetPtr &= 0xff80001fU;
348 // Immediate goes in bits 20:5 of MOVZ/MOVK instruction
349 *TargetPtr |= ((Result & 0xffff00000000ULL) >> (32 - 5));
350 // Shift is "lsl #32", in bits 22:21
351 *TargetPtr |= 2 << 21;
354 case ELF::R_AARCH64_MOVW_UABS_G1_NC: {
355 uint64_t Result = Value + Addend;
357 // AArch64 code is emitted with .rela relocations. The data already in any
358 // bits affected by the relocation on entry is garbage.
359 *TargetPtr &= 0xff80001fU;
360 // Immediate goes in bits 20:5 of MOVZ/MOVK instruction
361 *TargetPtr |= ((Result & 0xffff0000U) >> (16 - 5));
362 // Shift is "lsl #16", in bits 22:21
363 *TargetPtr |= 1 << 21;
366 case ELF::R_AARCH64_MOVW_UABS_G0_NC: {
367 uint64_t Result = Value + Addend;
369 // AArch64 code is emitted with .rela relocations. The data already in any
370 // bits affected by the relocation on entry is garbage.
371 *TargetPtr &= 0xff80001fU;
372 // Immediate goes in bits 20:5 of MOVZ/MOVK instruction
373 *TargetPtr |= ((Result & 0xffffU) << 5);
374 // Shift is "lsl #0", in bits 22:21. No action needed.
380 // FIXME: PR16013: this routine needs modification to handle repeated relocations.
381 void RuntimeDyldELF::resolveARMRelocation(const SectionEntry &Section,
386 // TODO: Add Thumb relocations.
387 uint32_t* TargetPtr = (uint32_t*)(Section.Address + Offset);
388 uint32_t FinalAddress = ((Section.LoadAddress + Offset) & 0xFFFFFFFF);
391 DEBUG(dbgs() << "resolveARMRelocation, LocalAddress: "
392 << Section.Address + Offset
393 << " FinalAddress: " << format("%p",FinalAddress)
394 << " Value: " << format("%x",Value)
395 << " Type: " << format("%x",Type)
396 << " Addend: " << format("%x",Addend)
401 llvm_unreachable("Not implemented relocation type!");
403 // Write a 32bit value to relocation address, taking into account the
404 // implicit addend encoded in the target.
405 case ELF::R_ARM_TARGET1 :
406 case ELF::R_ARM_ABS32 :
410 // Write first 16 bit of 32 bit value to the mov instruction.
411 // Last 4 bit should be shifted.
412 case ELF::R_ARM_MOVW_ABS_NC :
413 // We are not expecting any other addend in the relocation address.
414 // Using 0x000F0FFF because MOVW has its 16 bit immediate split into 2
415 // non-contiguous fields.
416 Value = Value & 0xFFFF;
417 *TargetPtr &= ~0x000F0FFF; // Not really right; see FIXME at top.
418 *TargetPtr |= Value & 0xFFF;
419 *TargetPtr |= ((Value >> 12) & 0xF) << 16;
422 // Write last 16 bit of 32 bit value to the mov instruction.
423 // Last 4 bit should be shifted.
424 case ELF::R_ARM_MOVT_ABS :
425 // We are not expecting any other addend in the relocation address.
426 // Use 0x000F0FFF for the same reason as R_ARM_MOVW_ABS_NC.
427 Value = (Value >> 16) & 0xFFFF;
428 *TargetPtr &= ~0x000F0FFF; // Not really right; see FIXME at top.
429 *TargetPtr |= Value & 0xFFF;
430 *TargetPtr |= ((Value >> 12) & 0xF) << 16;
433 // Write 24 bit relative value to the branch instruction.
434 case ELF::R_ARM_PC24 : // Fall through.
435 case ELF::R_ARM_CALL : // Fall through.
436 case ELF::R_ARM_JUMP24 :
437 int32_t RelValue = static_cast<int32_t>(Value - FinalAddress - 8);
438 RelValue = (RelValue & 0x03FFFFFC) >> 2;
439 *TargetPtr &= 0xFF000000;
440 *TargetPtr |= RelValue;
445 void RuntimeDyldELF::resolveMIPSRelocation(const SectionEntry &Section,
450 uint32_t* TargetPtr = (uint32_t*)(Section.Address + Offset);
453 DEBUG(dbgs() << "resolveMipselocation, LocalAddress: "
454 << Section.Address + Offset
456 << format("%p",Section.LoadAddress + Offset)
457 << " Value: " << format("%x",Value)
458 << " Type: " << format("%x",Type)
459 << " Addend: " << format("%x",Addend)
464 llvm_unreachable("Not implemented relocation type!");
467 *TargetPtr = Value + (*TargetPtr);
470 *TargetPtr = ((*TargetPtr) & 0xfc000000) | (( Value & 0x0fffffff) >> 2);
472 case ELF::R_MIPS_HI16:
473 // Get the higher 16-bits. Also add 1 if bit 15 is 1.
474 Value += ((*TargetPtr) & 0x0000ffff) << 16;
475 *TargetPtr = ((*TargetPtr) & 0xffff0000) |
476 (((Value + 0x8000) >> 16) & 0xffff);
478 case ELF::R_MIPS_LO16:
479 Value += ((*TargetPtr) & 0x0000ffff);
480 *TargetPtr = ((*TargetPtr) & 0xffff0000) | (Value & 0xffff);
485 // Return the .TOC. section address to R_PPC64_TOC relocations.
486 uint64_t RuntimeDyldELF::findPPC64TOC() const {
487 // The TOC consists of sections .got, .toc, .tocbss, .plt in that
488 // order. The TOC starts where the first of these sections starts.
489 SectionList::const_iterator it = Sections.begin();
490 SectionList::const_iterator ite = Sections.end();
491 for (; it != ite; ++it) {
492 if (it->Name == ".got" ||
493 it->Name == ".toc" ||
494 it->Name == ".tocbss" ||
499 // This may happen for
500 // * references to TOC base base (sym@toc, .odp relocation) without
502 // In this case just use the first section (which is usually
503 // the .odp) since the code won't reference the .toc base
505 it = Sections.begin();
508 // Per the ppc64-elf-linux ABI, The TOC base is TOC value plus 0x8000
509 // thus permitting a full 64 Kbytes segment.
510 return it->LoadAddress + 0x8000;
513 // Returns the sections and offset associated with the ODP entry referenced
515 void RuntimeDyldELF::findOPDEntrySection(ObjectImage &Obj,
516 ObjSectionToIDMap &LocalSections,
517 RelocationValueRef &Rel) {
518 // Get the ELF symbol value (st_value) to compare with Relocation offset in
522 for (section_iterator si = Obj.begin_sections(),
523 se = Obj.end_sections(); si != se; si.increment(err)) {
524 StringRef SectionName;
525 check(si->getName(SectionName));
526 if (SectionName != ".opd")
529 for (relocation_iterator i = si->begin_relocations(),
530 e = si->end_relocations(); i != e;) {
533 // The R_PPC64_ADDR64 relocation indicates the first field
536 check(i->getType(TypeFunc));
537 if (TypeFunc != ELF::R_PPC64_ADDR64) {
542 SymbolRef TargetSymbol;
543 uint64_t TargetSymbolOffset;
544 check(i->getSymbol(TargetSymbol));
545 check(i->getOffset(TargetSymbolOffset));
547 check(getELFRelocationAddend(*i, Addend));
549 i = i.increment(err);
554 // Just check if following relocation is a R_PPC64_TOC
556 check(i->getType(TypeTOC));
557 if (TypeTOC != ELF::R_PPC64_TOC)
560 // Finally compares the Symbol value and the target symbol offset
561 // to check if this .opd entry refers to the symbol the relocation
563 if (Rel.Addend != (intptr_t)TargetSymbolOffset)
566 section_iterator tsi(Obj.end_sections());
567 check(TargetSymbol.getSection(tsi));
568 Rel.SectionID = findOrEmitSection(Obj, (*tsi), true, LocalSections);
569 Rel.Addend = (intptr_t)Addend;
573 llvm_unreachable("Attempting to get address of ODP entry!");
576 // Relocation masks following the #lo(value), #hi(value), #higher(value),
577 // and #highest(value) macros defined in section 4.5.1. Relocation Types
578 // in PPC-elf64abi document.
581 uint16_t applyPPClo (uint64_t value)
583 return value & 0xffff;
587 uint16_t applyPPChi (uint64_t value)
589 return (value >> 16) & 0xffff;
593 uint16_t applyPPChigher (uint64_t value)
595 return (value >> 32) & 0xffff;
599 uint16_t applyPPChighest (uint64_t value)
601 return (value >> 48) & 0xffff;
604 void RuntimeDyldELF::resolvePPC64Relocation(const SectionEntry &Section,
609 uint8_t* LocalAddress = Section.Address + Offset;
612 llvm_unreachable("Relocation type not implemented yet!");
614 case ELF::R_PPC64_ADDR16_LO :
615 writeInt16BE(LocalAddress, applyPPClo (Value + Addend));
617 case ELF::R_PPC64_ADDR16_HI :
618 writeInt16BE(LocalAddress, applyPPChi (Value + Addend));
620 case ELF::R_PPC64_ADDR16_HIGHER :
621 writeInt16BE(LocalAddress, applyPPChigher (Value + Addend));
623 case ELF::R_PPC64_ADDR16_HIGHEST :
624 writeInt16BE(LocalAddress, applyPPChighest (Value + Addend));
626 case ELF::R_PPC64_ADDR14 : {
627 assert(((Value + Addend) & 3) == 0);
628 // Preserve the AA/LK bits in the branch instruction
629 uint8_t aalk = *(LocalAddress+3);
630 writeInt16BE(LocalAddress + 2, (aalk & 3) | ((Value + Addend) & 0xfffc));
632 case ELF::R_PPC64_ADDR32 : {
633 int32_t Result = static_cast<int32_t>(Value + Addend);
634 if (SignExtend32<32>(Result) != Result)
635 llvm_unreachable("Relocation R_PPC64_ADDR32 overflow");
636 writeInt32BE(LocalAddress, Result);
638 case ELF::R_PPC64_REL24 : {
639 uint64_t FinalAddress = (Section.LoadAddress + Offset);
640 int32_t delta = static_cast<int32_t>(Value - FinalAddress + Addend);
641 if (SignExtend32<24>(delta) != delta)
642 llvm_unreachable("Relocation R_PPC64_REL24 overflow");
643 // Generates a 'bl <address>' instruction
644 writeInt32BE(LocalAddress, 0x48000001 | (delta & 0x03FFFFFC));
646 case ELF::R_PPC64_REL32 : {
647 uint64_t FinalAddress = (Section.LoadAddress + Offset);
648 int32_t delta = static_cast<int32_t>(Value - FinalAddress + Addend);
649 if (SignExtend32<32>(delta) != delta)
650 llvm_unreachable("Relocation R_PPC64_REL32 overflow");
651 writeInt32BE(LocalAddress, delta);
653 case ELF::R_PPC64_REL64: {
654 uint64_t FinalAddress = (Section.LoadAddress + Offset);
655 uint64_t Delta = Value - FinalAddress + Addend;
656 writeInt64BE(LocalAddress, Delta);
658 case ELF::R_PPC64_ADDR64 :
659 writeInt64BE(LocalAddress, Value + Addend);
661 case ELF::R_PPC64_TOC :
662 writeInt64BE(LocalAddress, findPPC64TOC());
664 case ELF::R_PPC64_TOC16 : {
665 uint64_t TOCStart = findPPC64TOC();
666 Value = applyPPClo((Value + Addend) - TOCStart);
667 writeInt16BE(LocalAddress, applyPPClo(Value));
669 case ELF::R_PPC64_TOC16_DS : {
670 uint64_t TOCStart = findPPC64TOC();
671 Value = ((Value + Addend) - TOCStart);
672 writeInt16BE(LocalAddress, applyPPClo(Value));
677 void RuntimeDyldELF::resolveSystemZRelocation(const SectionEntry &Section,
682 uint8_t *LocalAddress = Section.Address + Offset;
685 llvm_unreachable("Relocation type not implemented yet!");
687 case ELF::R_390_PC16DBL:
688 case ELF::R_390_PLT16DBL: {
689 int64_t Delta = (Value + Addend) - (Section.LoadAddress + Offset);
690 assert(int16_t(Delta / 2) * 2 == Delta && "R_390_PC16DBL overflow");
691 writeInt16BE(LocalAddress, Delta / 2);
694 case ELF::R_390_PC32DBL:
695 case ELF::R_390_PLT32DBL: {
696 int64_t Delta = (Value + Addend) - (Section.LoadAddress + Offset);
697 assert(int32_t(Delta / 2) * 2 == Delta && "R_390_PC32DBL overflow");
698 writeInt32BE(LocalAddress, Delta / 2);
701 case ELF::R_390_PC32: {
702 int64_t Delta = (Value + Addend) - (Section.LoadAddress + Offset);
703 assert(int32_t(Delta) == Delta && "R_390_PC32 overflow");
704 writeInt32BE(LocalAddress, Delta);
708 writeInt64BE(LocalAddress, Value + Addend);
713 void RuntimeDyldELF::resolveRelocation(const RelocationEntry &RE,
715 const SectionEntry &Section = Sections[RE.SectionID];
716 return resolveRelocation(Section, RE.Offset, Value, RE.RelType, RE.Addend);
719 void RuntimeDyldELF::resolveRelocation(const SectionEntry &Section,
726 resolveX86_64Relocation(Section, Offset, Value, Type, Addend);
729 resolveX86Relocation(Section, Offset,
730 (uint32_t)(Value & 0xffffffffL), Type,
731 (uint32_t)(Addend & 0xffffffffL));
733 case Triple::aarch64:
734 resolveAArch64Relocation(Section, Offset, Value, Type, Addend);
736 case Triple::arm: // Fall through.
738 resolveARMRelocation(Section, Offset,
739 (uint32_t)(Value & 0xffffffffL), Type,
740 (uint32_t)(Addend & 0xffffffffL));
742 case Triple::mips: // Fall through.
744 resolveMIPSRelocation(Section, Offset,
745 (uint32_t)(Value & 0xffffffffL), Type,
746 (uint32_t)(Addend & 0xffffffffL));
749 resolvePPC64Relocation(Section, Offset, Value, Type, Addend);
751 case Triple::systemz:
752 resolveSystemZRelocation(Section, Offset, Value, Type, Addend);
754 default: llvm_unreachable("Unsupported CPU type!");
758 void RuntimeDyldELF::processRelocationRef(unsigned SectionID,
761 ObjSectionToIDMap &ObjSectionToID,
762 const SymbolTableMap &Symbols,
765 Check(RelI.getType(RelType));
767 Check(getELFRelocationAddend(RelI, Addend));
769 Check(RelI.getSymbol(Symbol));
771 // Obtain the symbol name which is referenced in the relocation
772 StringRef TargetName;
773 Symbol.getName(TargetName);
774 DEBUG(dbgs() << "\t\tRelType: " << RelType
775 << " Addend: " << Addend
776 << " TargetName: " << TargetName
778 RelocationValueRef Value;
779 // First search for the symbol in the local symbol table
780 SymbolTableMap::const_iterator lsi = Symbols.find(TargetName.data());
781 SymbolRef::Type SymType;
782 Symbol.getType(SymType);
783 if (lsi != Symbols.end()) {
784 Value.SectionID = lsi->second.first;
785 Value.Addend = lsi->second.second + Addend;
787 // Search for the symbol in the global symbol table
788 SymbolTableMap::const_iterator gsi =
789 GlobalSymbolTable.find(TargetName.data());
790 if (gsi != GlobalSymbolTable.end()) {
791 Value.SectionID = gsi->second.first;
792 Value.Addend = gsi->second.second + Addend;
795 case SymbolRef::ST_Debug: {
796 // TODO: Now ELF SymbolRef::ST_Debug = STT_SECTION, it's not obviously
797 // and can be changed by another developers. Maybe best way is add
798 // a new symbol type ST_Section to SymbolRef and use it.
799 section_iterator si(Obj.end_sections());
800 Symbol.getSection(si);
801 if (si == Obj.end_sections())
802 llvm_unreachable("Symbol section not found, bad object file format!");
803 DEBUG(dbgs() << "\t\tThis is section symbol\n");
804 // Default to 'true' in case isText fails (though it never does).
807 Value.SectionID = findOrEmitSection(Obj,
811 Value.Addend = Addend;
814 case SymbolRef::ST_Unknown: {
815 Value.SymbolName = TargetName.data();
816 Value.Addend = Addend;
820 llvm_unreachable("Unresolved symbol type!");
826 Check(RelI.getOffset(Offset));
828 DEBUG(dbgs() << "\t\tSectionID: " << SectionID
829 << " Offset: " << Offset
831 if (Arch == Triple::aarch64 &&
832 (RelType == ELF::R_AARCH64_CALL26 ||
833 RelType == ELF::R_AARCH64_JUMP26)) {
834 // This is an AArch64 branch relocation, need to use a stub function.
835 DEBUG(dbgs() << "\t\tThis is an AArch64 branch relocation.");
836 SectionEntry &Section = Sections[SectionID];
838 // Look for an existing stub.
839 StubMap::const_iterator i = Stubs.find(Value);
840 if (i != Stubs.end()) {
841 resolveRelocation(Section, Offset,
842 (uint64_t)Section.Address + i->second, RelType, 0);
843 DEBUG(dbgs() << " Stub function found\n");
845 // Create a new stub function.
846 DEBUG(dbgs() << " Create a new stub function\n");
847 Stubs[Value] = Section.StubOffset;
848 uint8_t *StubTargetAddr = createStubFunction(Section.Address +
851 RelocationEntry REmovz_g3(SectionID,
852 StubTargetAddr - Section.Address,
853 ELF::R_AARCH64_MOVW_UABS_G3, Value.Addend);
854 RelocationEntry REmovk_g2(SectionID,
855 StubTargetAddr - Section.Address + 4,
856 ELF::R_AARCH64_MOVW_UABS_G2_NC, Value.Addend);
857 RelocationEntry REmovk_g1(SectionID,
858 StubTargetAddr - Section.Address + 8,
859 ELF::R_AARCH64_MOVW_UABS_G1_NC, Value.Addend);
860 RelocationEntry REmovk_g0(SectionID,
861 StubTargetAddr - Section.Address + 12,
862 ELF::R_AARCH64_MOVW_UABS_G0_NC, Value.Addend);
864 if (Value.SymbolName) {
865 addRelocationForSymbol(REmovz_g3, Value.SymbolName);
866 addRelocationForSymbol(REmovk_g2, Value.SymbolName);
867 addRelocationForSymbol(REmovk_g1, Value.SymbolName);
868 addRelocationForSymbol(REmovk_g0, Value.SymbolName);
870 addRelocationForSection(REmovz_g3, Value.SectionID);
871 addRelocationForSection(REmovk_g2, Value.SectionID);
872 addRelocationForSection(REmovk_g1, Value.SectionID);
873 addRelocationForSection(REmovk_g0, Value.SectionID);
875 resolveRelocation(Section, Offset,
876 (uint64_t)Section.Address + Section.StubOffset,
878 Section.StubOffset += getMaxStubSize();
880 } else if (Arch == Triple::arm &&
881 (RelType == ELF::R_ARM_PC24 ||
882 RelType == ELF::R_ARM_CALL ||
883 RelType == ELF::R_ARM_JUMP24)) {
884 // This is an ARM branch relocation, need to use a stub function.
885 DEBUG(dbgs() << "\t\tThis is an ARM branch relocation.");
886 SectionEntry &Section = Sections[SectionID];
888 // Look for an existing stub.
889 StubMap::const_iterator i = Stubs.find(Value);
890 if (i != Stubs.end()) {
891 resolveRelocation(Section, Offset,
892 (uint64_t)Section.Address + i->second, RelType, 0);
893 DEBUG(dbgs() << " Stub function found\n");
895 // Create a new stub function.
896 DEBUG(dbgs() << " Create a new stub function\n");
897 Stubs[Value] = Section.StubOffset;
898 uint8_t *StubTargetAddr = createStubFunction(Section.Address +
900 RelocationEntry RE(SectionID, StubTargetAddr - Section.Address,
901 ELF::R_ARM_ABS32, Value.Addend);
902 if (Value.SymbolName)
903 addRelocationForSymbol(RE, Value.SymbolName);
905 addRelocationForSection(RE, Value.SectionID);
907 resolveRelocation(Section, Offset,
908 (uint64_t)Section.Address + Section.StubOffset,
910 Section.StubOffset += getMaxStubSize();
912 } else if ((Arch == Triple::mipsel || Arch == Triple::mips) &&
913 RelType == ELF::R_MIPS_26) {
914 // This is an Mips branch relocation, need to use a stub function.
915 DEBUG(dbgs() << "\t\tThis is a Mips branch relocation.");
916 SectionEntry &Section = Sections[SectionID];
917 uint8_t *Target = Section.Address + Offset;
918 uint32_t *TargetAddress = (uint32_t *)Target;
920 // Extract the addend from the instruction.
921 uint32_t Addend = ((*TargetAddress) & 0x03ffffff) << 2;
923 Value.Addend += Addend;
925 // Look up for existing stub.
926 StubMap::const_iterator i = Stubs.find(Value);
927 if (i != Stubs.end()) {
928 resolveRelocation(Section, Offset,
929 (uint64_t)Section.Address + i->second, RelType, 0);
930 DEBUG(dbgs() << " Stub function found\n");
932 // Create a new stub function.
933 DEBUG(dbgs() << " Create a new stub function\n");
934 Stubs[Value] = Section.StubOffset;
935 uint8_t *StubTargetAddr = createStubFunction(Section.Address +
938 // Creating Hi and Lo relocations for the filled stub instructions.
939 RelocationEntry REHi(SectionID,
940 StubTargetAddr - Section.Address,
941 ELF::R_MIPS_HI16, Value.Addend);
942 RelocationEntry RELo(SectionID,
943 StubTargetAddr - Section.Address + 4,
944 ELF::R_MIPS_LO16, Value.Addend);
946 if (Value.SymbolName) {
947 addRelocationForSymbol(REHi, Value.SymbolName);
948 addRelocationForSymbol(RELo, Value.SymbolName);
950 addRelocationForSection(REHi, Value.SectionID);
951 addRelocationForSection(RELo, Value.SectionID);
954 resolveRelocation(Section, Offset,
955 (uint64_t)Section.Address + Section.StubOffset,
957 Section.StubOffset += getMaxStubSize();
959 } else if (Arch == Triple::ppc64) {
960 if (RelType == ELF::R_PPC64_REL24) {
961 // A PPC branch relocation will need a stub function if the target is
962 // an external symbol (Symbol::ST_Unknown) or if the target address
963 // is not within the signed 24-bits branch address.
964 SectionEntry &Section = Sections[SectionID];
965 uint8_t *Target = Section.Address + Offset;
966 bool RangeOverflow = false;
967 if (SymType != SymbolRef::ST_Unknown) {
968 // A function call may points to the .opd entry, so the final symbol value
969 // in calculated based in the relocation values in .opd section.
970 findOPDEntrySection(Obj, ObjSectionToID, Value);
971 uint8_t *RelocTarget = Sections[Value.SectionID].Address + Value.Addend;
972 int32_t delta = static_cast<int32_t>(Target - RelocTarget);
973 // If it is within 24-bits branch range, just set the branch target
974 if (SignExtend32<24>(delta) == delta) {
975 RelocationEntry RE(SectionID, Offset, RelType, Value.Addend);
976 if (Value.SymbolName)
977 addRelocationForSymbol(RE, Value.SymbolName);
979 addRelocationForSection(RE, Value.SectionID);
981 RangeOverflow = true;
984 if (SymType == SymbolRef::ST_Unknown || RangeOverflow == true) {
985 // It is an external symbol (SymbolRef::ST_Unknown) or within a range
986 // larger than 24-bits.
987 StubMap::const_iterator i = Stubs.find(Value);
988 if (i != Stubs.end()) {
989 // Symbol function stub already created, just relocate to it
990 resolveRelocation(Section, Offset,
991 (uint64_t)Section.Address + i->second, RelType, 0);
992 DEBUG(dbgs() << " Stub function found\n");
994 // Create a new stub function.
995 DEBUG(dbgs() << " Create a new stub function\n");
996 Stubs[Value] = Section.StubOffset;
997 uint8_t *StubTargetAddr = createStubFunction(Section.Address +
999 RelocationEntry RE(SectionID, StubTargetAddr - Section.Address,
1000 ELF::R_PPC64_ADDR64, Value.Addend);
1002 // Generates the 64-bits address loads as exemplified in section
1003 // 4.5.1 in PPC64 ELF ABI.
1004 RelocationEntry REhst(SectionID,
1005 StubTargetAddr - Section.Address + 2,
1006 ELF::R_PPC64_ADDR16_HIGHEST, Value.Addend);
1007 RelocationEntry REhr(SectionID,
1008 StubTargetAddr - Section.Address + 6,
1009 ELF::R_PPC64_ADDR16_HIGHER, Value.Addend);
1010 RelocationEntry REh(SectionID,
1011 StubTargetAddr - Section.Address + 14,
1012 ELF::R_PPC64_ADDR16_HI, Value.Addend);
1013 RelocationEntry REl(SectionID,
1014 StubTargetAddr - Section.Address + 18,
1015 ELF::R_PPC64_ADDR16_LO, Value.Addend);
1017 if (Value.SymbolName) {
1018 addRelocationForSymbol(REhst, Value.SymbolName);
1019 addRelocationForSymbol(REhr, Value.SymbolName);
1020 addRelocationForSymbol(REh, Value.SymbolName);
1021 addRelocationForSymbol(REl, Value.SymbolName);
1023 addRelocationForSection(REhst, Value.SectionID);
1024 addRelocationForSection(REhr, Value.SectionID);
1025 addRelocationForSection(REh, Value.SectionID);
1026 addRelocationForSection(REl, Value.SectionID);
1029 resolveRelocation(Section, Offset,
1030 (uint64_t)Section.Address + Section.StubOffset,
1032 if (SymType == SymbolRef::ST_Unknown)
1033 // Restore the TOC for external calls
1034 writeInt32BE(Target+4, 0xE8410028); // ld r2,40(r1)
1035 Section.StubOffset += getMaxStubSize();
1039 RelocationEntry RE(SectionID, Offset, RelType, Value.Addend);
1040 // Extra check to avoid relocation againt empty symbols (usually
1041 // the R_PPC64_TOC).
1042 if (Value.SymbolName && !TargetName.empty())
1043 addRelocationForSymbol(RE, Value.SymbolName);
1045 addRelocationForSection(RE, Value.SectionID);
1047 } else if (Arch == Triple::systemz &&
1048 (RelType == ELF::R_390_PLT32DBL ||
1049 RelType == ELF::R_390_GOTENT)) {
1050 // Create function stubs for both PLT and GOT references, regardless of
1051 // whether the GOT reference is to data or code. The stub contains the
1052 // full address of the symbol, as needed by GOT references, and the
1053 // executable part only adds an overhead of 8 bytes.
1055 // We could try to conserve space by allocating the code and data
1056 // parts of the stub separately. However, as things stand, we allocate
1057 // a stub for every relocation, so using a GOT in JIT code should be
1058 // no less space efficient than using an explicit constant pool.
1059 DEBUG(dbgs() << "\t\tThis is a SystemZ indirect relocation.");
1060 SectionEntry &Section = Sections[SectionID];
1062 // Look for an existing stub.
1063 StubMap::const_iterator i = Stubs.find(Value);
1064 uintptr_t StubAddress;
1065 if (i != Stubs.end()) {
1066 StubAddress = uintptr_t(Section.Address) + i->second;
1067 DEBUG(dbgs() << " Stub function found\n");
1069 // Create a new stub function.
1070 DEBUG(dbgs() << " Create a new stub function\n");
1072 uintptr_t BaseAddress = uintptr_t(Section.Address);
1073 uintptr_t StubAlignment = getStubAlignment();
1074 StubAddress = (BaseAddress + Section.StubOffset +
1075 StubAlignment - 1) & -StubAlignment;
1076 unsigned StubOffset = StubAddress - BaseAddress;
1078 Stubs[Value] = StubOffset;
1079 createStubFunction((uint8_t *)StubAddress);
1080 RelocationEntry RE(SectionID, StubOffset + 8,
1081 ELF::R_390_64, Value.Addend - Addend);
1082 if (Value.SymbolName)
1083 addRelocationForSymbol(RE, Value.SymbolName);
1085 addRelocationForSection(RE, Value.SectionID);
1086 Section.StubOffset = StubOffset + getMaxStubSize();
1089 if (RelType == ELF::R_390_GOTENT)
1090 resolveRelocation(Section, Offset, StubAddress + 8,
1091 ELF::R_390_PC32DBL, Addend);
1093 resolveRelocation(Section, Offset, StubAddress, RelType, Addend);
1095 RelocationEntry RE(SectionID, Offset, RelType, Value.Addend);
1096 if (Value.SymbolName)
1097 addRelocationForSymbol(RE, Value.SymbolName);
1099 addRelocationForSection(RE, Value.SectionID);
1103 bool RuntimeDyldELF::isCompatibleFormat(const ObjectBuffer *Buffer) const {
1104 if (Buffer->getBufferSize() < strlen(ELF::ElfMagic))
1106 return (memcmp(Buffer->getBufferStart(), ELF::ElfMagic, strlen(ELF::ElfMagic))) == 0;