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 must be "lsl #48", in bits 22:21
338 assert((*TargetPtr >> 21 & 0x3) == 3 && "invalid shift for relocation");
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 must be "lsl #32", in bits 22:21
351 assert((*TargetPtr >> 21 & 0x3) == 2 && "invalid shift for relocation");
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 must be "lsl #16", in bits 22:2
363 assert((*TargetPtr >> 21 & 0x3) == 1 && "invalid shift for relocation");
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 must be "lsl #0", in bits 22:21.
375 assert((*TargetPtr >> 21 & 0x3) == 0 && "invalid shift for relocation");
381 void RuntimeDyldELF::resolveARMRelocation(const SectionEntry &Section,
386 // TODO: Add Thumb relocations.
387 uint32_t *Placeholder = reinterpret_cast<uint32_t*>(Section.ObjAddress +
389 uint32_t* TargetPtr = (uint32_t*)(Section.Address + Offset);
390 uint32_t FinalAddress = ((Section.LoadAddress + Offset) & 0xFFFFFFFF);
393 DEBUG(dbgs() << "resolveARMRelocation, LocalAddress: "
394 << Section.Address + Offset
395 << " FinalAddress: " << format("%p",FinalAddress)
396 << " Value: " << format("%x",Value)
397 << " Type: " << format("%x",Type)
398 << " Addend: " << format("%x",Addend)
403 llvm_unreachable("Not implemented relocation type!");
405 // Write a 32bit value to relocation address, taking into account the
406 // implicit addend encoded in the target.
407 case ELF::R_ARM_TARGET1:
408 case ELF::R_ARM_ABS32:
409 *TargetPtr = *Placeholder + Value;
411 // Write first 16 bit of 32 bit value to the mov instruction.
412 // Last 4 bit should be shifted.
413 case ELF::R_ARM_MOVW_ABS_NC:
414 // We are not expecting any other addend in the relocation address.
415 // Using 0x000F0FFF because MOVW has its 16 bit immediate split into 2
416 // non-contiguous fields.
417 assert((*Placeholder & 0x000F0FFF) == 0);
418 Value = Value & 0xFFFF;
419 *TargetPtr = *Placeholder | (Value & 0xFFF);
420 *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 assert((*Placeholder & 0x000F0FFF) == 0);
429 Value = (Value >> 16) & 0xFFFF;
430 *TargetPtr = *Placeholder | (Value & 0xFFF);
431 *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 assert((*TargetPtr & 0xFFFFFF) == 0xFFFFFE);
440 *TargetPtr &= 0xFF000000;
441 *TargetPtr |= RelValue;
444 case ELF::R_ARM_PRIVATE_0:
445 // This relocation is reserved by the ARM ELF ABI for internal use. We
446 // appropriate it here to act as an R_ARM_ABS32 without any addend for use
447 // in the stubs created during JIT (which can't put an addend into the
448 // original object file).
454 void RuntimeDyldELF::resolveMIPSRelocation(const SectionEntry &Section,
459 uint32_t *Placeholder = reinterpret_cast<uint32_t*>(Section.ObjAddress +
461 uint32_t* TargetPtr = (uint32_t*)(Section.Address + Offset);
464 DEBUG(dbgs() << "resolveMipselocation, LocalAddress: "
465 << Section.Address + Offset
467 << format("%p",Section.LoadAddress + Offset)
468 << " Value: " << format("%x",Value)
469 << " Type: " << format("%x",Type)
470 << " Addend: " << format("%x",Addend)
475 llvm_unreachable("Not implemented relocation type!");
478 *TargetPtr = Value + (*Placeholder);
481 *TargetPtr = ((*Placeholder) & 0xfc000000) | (( Value & 0x0fffffff) >> 2);
483 case ELF::R_MIPS_HI16:
484 // Get the higher 16-bits. Also add 1 if bit 15 is 1.
485 Value += ((*Placeholder) & 0x0000ffff) << 16;
486 *TargetPtr = ((*Placeholder) & 0xffff0000) |
487 (((Value + 0x8000) >> 16) & 0xffff);
489 case ELF::R_MIPS_LO16:
490 Value += ((*Placeholder) & 0x0000ffff);
491 *TargetPtr = ((*Placeholder) & 0xffff0000) | (Value & 0xffff);
493 case ELF::R_MIPS_UNUSED1:
494 // Similar to ELF::R_ARM_PRIVATE_0, R_MIPS_UNUSED1 and R_MIPS_UNUSED2
495 // are used for internal JIT purpose. These relocations are similar to
496 // R_MIPS_HI16 and R_MIPS_LO16, but they do not take any addend into
498 *TargetPtr = ((*TargetPtr) & 0xffff0000) |
499 (((Value + 0x8000) >> 16) & 0xffff);
501 case ELF::R_MIPS_UNUSED2:
502 *TargetPtr = ((*TargetPtr) & 0xffff0000) | (Value & 0xffff);
507 // Return the .TOC. section address to R_PPC64_TOC relocations.
508 uint64_t RuntimeDyldELF::findPPC64TOC() const {
509 // The TOC consists of sections .got, .toc, .tocbss, .plt in that
510 // order. The TOC starts where the first of these sections starts.
511 SectionList::const_iterator it = Sections.begin();
512 SectionList::const_iterator ite = Sections.end();
513 for (; it != ite; ++it) {
514 if (it->Name == ".got" ||
515 it->Name == ".toc" ||
516 it->Name == ".tocbss" ||
521 // This may happen for
522 // * references to TOC base base (sym@toc, .odp relocation) without
524 // In this case just use the first section (which is usually
525 // the .odp) since the code won't reference the .toc base
527 it = Sections.begin();
530 // Per the ppc64-elf-linux ABI, The TOC base is TOC value plus 0x8000
531 // thus permitting a full 64 Kbytes segment.
532 return it->LoadAddress + 0x8000;
535 // Returns the sections and offset associated with the ODP entry referenced
537 void RuntimeDyldELF::findOPDEntrySection(ObjectImage &Obj,
538 ObjSectionToIDMap &LocalSections,
539 RelocationValueRef &Rel) {
540 // Get the ELF symbol value (st_value) to compare with Relocation offset in
544 for (section_iterator si = Obj.begin_sections(),
545 se = Obj.end_sections(); si != se; si.increment(err)) {
546 section_iterator RelSecI = si->getRelocatedSection();
547 if (RelSecI == Obj.end_sections())
550 StringRef RelSectionName;
551 check(RelSecI->getName(RelSectionName));
552 if (RelSectionName != ".opd")
555 for (relocation_iterator i = si->begin_relocations(),
556 e = si->end_relocations(); i != e;) {
559 // The R_PPC64_ADDR64 relocation indicates the first field
562 check(i->getType(TypeFunc));
563 if (TypeFunc != ELF::R_PPC64_ADDR64) {
568 uint64_t TargetSymbolOffset;
569 symbol_iterator TargetSymbol = i->getSymbol();
570 check(i->getOffset(TargetSymbolOffset));
572 check(getELFRelocationAddend(*i, Addend));
574 i = i.increment(err);
579 // Just check if following relocation is a R_PPC64_TOC
581 check(i->getType(TypeTOC));
582 if (TypeTOC != ELF::R_PPC64_TOC)
585 // Finally compares the Symbol value and the target symbol offset
586 // to check if this .opd entry refers to the symbol the relocation
588 if (Rel.Addend != (intptr_t)TargetSymbolOffset)
591 section_iterator tsi(Obj.end_sections());
592 check(TargetSymbol->getSection(tsi));
593 Rel.SectionID = findOrEmitSection(Obj, (*tsi), true, LocalSections);
594 Rel.Addend = (intptr_t)Addend;
598 llvm_unreachable("Attempting to get address of ODP entry!");
601 // Relocation masks following the #lo(value), #hi(value), #higher(value),
602 // and #highest(value) macros defined in section 4.5.1. Relocation Types
603 // in PPC-elf64abi document.
606 uint16_t applyPPClo (uint64_t value)
608 return value & 0xffff;
612 uint16_t applyPPChi (uint64_t value)
614 return (value >> 16) & 0xffff;
618 uint16_t applyPPChigher (uint64_t value)
620 return (value >> 32) & 0xffff;
624 uint16_t applyPPChighest (uint64_t value)
626 return (value >> 48) & 0xffff;
629 void RuntimeDyldELF::resolvePPC64Relocation(const SectionEntry &Section,
634 uint8_t* LocalAddress = Section.Address + Offset;
637 llvm_unreachable("Relocation type not implemented yet!");
639 case ELF::R_PPC64_ADDR16_LO :
640 writeInt16BE(LocalAddress, applyPPClo (Value + Addend));
642 case ELF::R_PPC64_ADDR16_HI :
643 writeInt16BE(LocalAddress, applyPPChi (Value + Addend));
645 case ELF::R_PPC64_ADDR16_HIGHER :
646 writeInt16BE(LocalAddress, applyPPChigher (Value + Addend));
648 case ELF::R_PPC64_ADDR16_HIGHEST :
649 writeInt16BE(LocalAddress, applyPPChighest (Value + Addend));
651 case ELF::R_PPC64_ADDR14 : {
652 assert(((Value + Addend) & 3) == 0);
653 // Preserve the AA/LK bits in the branch instruction
654 uint8_t aalk = *(LocalAddress+3);
655 writeInt16BE(LocalAddress + 2, (aalk & 3) | ((Value + Addend) & 0xfffc));
657 case ELF::R_PPC64_ADDR32 : {
658 int32_t Result = static_cast<int32_t>(Value + Addend);
659 if (SignExtend32<32>(Result) != Result)
660 llvm_unreachable("Relocation R_PPC64_ADDR32 overflow");
661 writeInt32BE(LocalAddress, Result);
663 case ELF::R_PPC64_REL24 : {
664 uint64_t FinalAddress = (Section.LoadAddress + Offset);
665 int32_t delta = static_cast<int32_t>(Value - FinalAddress + Addend);
666 if (SignExtend32<24>(delta) != delta)
667 llvm_unreachable("Relocation R_PPC64_REL24 overflow");
668 // Generates a 'bl <address>' instruction
669 writeInt32BE(LocalAddress, 0x48000001 | (delta & 0x03FFFFFC));
671 case ELF::R_PPC64_REL32 : {
672 uint64_t FinalAddress = (Section.LoadAddress + Offset);
673 int32_t delta = static_cast<int32_t>(Value - FinalAddress + Addend);
674 if (SignExtend32<32>(delta) != delta)
675 llvm_unreachable("Relocation R_PPC64_REL32 overflow");
676 writeInt32BE(LocalAddress, delta);
678 case ELF::R_PPC64_REL64: {
679 uint64_t FinalAddress = (Section.LoadAddress + Offset);
680 uint64_t Delta = Value - FinalAddress + Addend;
681 writeInt64BE(LocalAddress, Delta);
683 case ELF::R_PPC64_ADDR64 :
684 writeInt64BE(LocalAddress, Value + Addend);
686 case ELF::R_PPC64_TOC :
687 writeInt64BE(LocalAddress, findPPC64TOC());
689 case ELF::R_PPC64_TOC16 : {
690 uint64_t TOCStart = findPPC64TOC();
691 Value = applyPPClo((Value + Addend) - TOCStart);
692 writeInt16BE(LocalAddress, applyPPClo(Value));
694 case ELF::R_PPC64_TOC16_DS : {
695 uint64_t TOCStart = findPPC64TOC();
696 Value = ((Value + Addend) - TOCStart);
697 writeInt16BE(LocalAddress, applyPPClo(Value));
702 void RuntimeDyldELF::resolveSystemZRelocation(const SectionEntry &Section,
707 uint8_t *LocalAddress = Section.Address + Offset;
710 llvm_unreachable("Relocation type not implemented yet!");
712 case ELF::R_390_PC16DBL:
713 case ELF::R_390_PLT16DBL: {
714 int64_t Delta = (Value + Addend) - (Section.LoadAddress + Offset);
715 assert(int16_t(Delta / 2) * 2 == Delta && "R_390_PC16DBL overflow");
716 writeInt16BE(LocalAddress, Delta / 2);
719 case ELF::R_390_PC32DBL:
720 case ELF::R_390_PLT32DBL: {
721 int64_t Delta = (Value + Addend) - (Section.LoadAddress + Offset);
722 assert(int32_t(Delta / 2) * 2 == Delta && "R_390_PC32DBL overflow");
723 writeInt32BE(LocalAddress, Delta / 2);
726 case ELF::R_390_PC32: {
727 int64_t Delta = (Value + Addend) - (Section.LoadAddress + Offset);
728 assert(int32_t(Delta) == Delta && "R_390_PC32 overflow");
729 writeInt32BE(LocalAddress, Delta);
733 writeInt64BE(LocalAddress, Value + Addend);
738 void RuntimeDyldELF::resolveRelocation(const RelocationEntry &RE,
740 const SectionEntry &Section = Sections[RE.SectionID];
741 return resolveRelocation(Section, RE.Offset, Value, RE.RelType, RE.Addend);
744 void RuntimeDyldELF::resolveRelocation(const SectionEntry &Section,
751 resolveX86_64Relocation(Section, Offset, Value, Type, Addend);
754 resolveX86Relocation(Section, Offset,
755 (uint32_t)(Value & 0xffffffffL), Type,
756 (uint32_t)(Addend & 0xffffffffL));
758 case Triple::aarch64:
759 resolveAArch64Relocation(Section, Offset, Value, Type, Addend);
761 case Triple::arm: // Fall through.
763 resolveARMRelocation(Section, Offset,
764 (uint32_t)(Value & 0xffffffffL), Type,
765 (uint32_t)(Addend & 0xffffffffL));
767 case Triple::mips: // Fall through.
769 resolveMIPSRelocation(Section, Offset,
770 (uint32_t)(Value & 0xffffffffL), Type,
771 (uint32_t)(Addend & 0xffffffffL));
774 resolvePPC64Relocation(Section, Offset, Value, Type, Addend);
776 case Triple::systemz:
777 resolveSystemZRelocation(Section, Offset, Value, Type, Addend);
779 default: llvm_unreachable("Unsupported CPU type!");
783 void RuntimeDyldELF::processRelocationRef(unsigned SectionID,
786 ObjSectionToIDMap &ObjSectionToID,
787 const SymbolTableMap &Symbols,
790 Check(RelI.getType(RelType));
792 Check(getELFRelocationAddend(RelI, Addend));
793 symbol_iterator Symbol = RelI.getSymbol();
795 // Obtain the symbol name which is referenced in the relocation
796 StringRef TargetName;
797 if (Symbol != Obj.end_symbols())
798 Symbol->getName(TargetName);
799 DEBUG(dbgs() << "\t\tRelType: " << RelType
800 << " Addend: " << Addend
801 << " TargetName: " << TargetName
803 RelocationValueRef Value;
804 // First search for the symbol in the local symbol table
805 SymbolTableMap::const_iterator lsi = Symbols.end();
806 SymbolRef::Type SymType = SymbolRef::ST_Unknown;
807 if (Symbol != Obj.end_symbols()) {
808 lsi = Symbols.find(TargetName.data());
809 Symbol->getType(SymType);
811 if (lsi != Symbols.end()) {
812 Value.SectionID = lsi->second.first;
813 Value.Addend = lsi->second.second + Addend;
815 // Search for the symbol in the global symbol table
816 SymbolTableMap::const_iterator gsi = GlobalSymbolTable.end();
817 if (Symbol != Obj.end_symbols())
818 gsi = GlobalSymbolTable.find(TargetName.data());
819 if (gsi != GlobalSymbolTable.end()) {
820 Value.SectionID = gsi->second.first;
821 Value.Addend = gsi->second.second + Addend;
824 case SymbolRef::ST_Debug: {
825 // TODO: Now ELF SymbolRef::ST_Debug = STT_SECTION, it's not obviously
826 // and can be changed by another developers. Maybe best way is add
827 // a new symbol type ST_Section to SymbolRef and use it.
828 section_iterator si(Obj.end_sections());
829 Symbol->getSection(si);
830 if (si == Obj.end_sections())
831 llvm_unreachable("Symbol section not found, bad object file format!");
832 DEBUG(dbgs() << "\t\tThis is section symbol\n");
833 // Default to 'true' in case isText fails (though it never does).
836 Value.SectionID = findOrEmitSection(Obj,
840 Value.Addend = Addend;
843 case SymbolRef::ST_Unknown: {
844 Value.SymbolName = TargetName.data();
845 Value.Addend = Addend;
849 llvm_unreachable("Unresolved symbol type!");
855 Check(RelI.getOffset(Offset));
857 DEBUG(dbgs() << "\t\tSectionID: " << SectionID
858 << " Offset: " << Offset
860 if (Arch == Triple::aarch64 &&
861 (RelType == ELF::R_AARCH64_CALL26 ||
862 RelType == ELF::R_AARCH64_JUMP26)) {
863 // This is an AArch64 branch relocation, need to use a stub function.
864 DEBUG(dbgs() << "\t\tThis is an AArch64 branch relocation.");
865 SectionEntry &Section = Sections[SectionID];
867 // Look for an existing stub.
868 StubMap::const_iterator i = Stubs.find(Value);
869 if (i != Stubs.end()) {
870 resolveRelocation(Section, Offset,
871 (uint64_t)Section.Address + i->second, RelType, 0);
872 DEBUG(dbgs() << " Stub function found\n");
874 // Create a new stub function.
875 DEBUG(dbgs() << " Create a new stub function\n");
876 Stubs[Value] = Section.StubOffset;
877 uint8_t *StubTargetAddr = createStubFunction(Section.Address +
880 RelocationEntry REmovz_g3(SectionID,
881 StubTargetAddr - Section.Address,
882 ELF::R_AARCH64_MOVW_UABS_G3, Value.Addend);
883 RelocationEntry REmovk_g2(SectionID,
884 StubTargetAddr - Section.Address + 4,
885 ELF::R_AARCH64_MOVW_UABS_G2_NC, Value.Addend);
886 RelocationEntry REmovk_g1(SectionID,
887 StubTargetAddr - Section.Address + 8,
888 ELF::R_AARCH64_MOVW_UABS_G1_NC, Value.Addend);
889 RelocationEntry REmovk_g0(SectionID,
890 StubTargetAddr - Section.Address + 12,
891 ELF::R_AARCH64_MOVW_UABS_G0_NC, Value.Addend);
893 if (Value.SymbolName) {
894 addRelocationForSymbol(REmovz_g3, Value.SymbolName);
895 addRelocationForSymbol(REmovk_g2, Value.SymbolName);
896 addRelocationForSymbol(REmovk_g1, Value.SymbolName);
897 addRelocationForSymbol(REmovk_g0, Value.SymbolName);
899 addRelocationForSection(REmovz_g3, Value.SectionID);
900 addRelocationForSection(REmovk_g2, Value.SectionID);
901 addRelocationForSection(REmovk_g1, Value.SectionID);
902 addRelocationForSection(REmovk_g0, Value.SectionID);
904 resolveRelocation(Section, Offset,
905 (uint64_t)Section.Address + Section.StubOffset,
907 Section.StubOffset += getMaxStubSize();
909 } else if (Arch == Triple::arm &&
910 (RelType == ELF::R_ARM_PC24 ||
911 RelType == ELF::R_ARM_CALL ||
912 RelType == ELF::R_ARM_JUMP24)) {
913 // This is an ARM branch relocation, need to use a stub function.
914 DEBUG(dbgs() << "\t\tThis is an ARM branch relocation.");
915 SectionEntry &Section = Sections[SectionID];
917 // Look for an existing stub.
918 StubMap::const_iterator i = Stubs.find(Value);
919 if (i != Stubs.end()) {
920 resolveRelocation(Section, Offset,
921 (uint64_t)Section.Address + i->second, RelType, 0);
922 DEBUG(dbgs() << " Stub function found\n");
924 // Create a new stub function.
925 DEBUG(dbgs() << " Create a new stub function\n");
926 Stubs[Value] = Section.StubOffset;
927 uint8_t *StubTargetAddr = createStubFunction(Section.Address +
929 RelocationEntry RE(SectionID, StubTargetAddr - Section.Address,
930 ELF::R_ARM_PRIVATE_0, Value.Addend);
931 if (Value.SymbolName)
932 addRelocationForSymbol(RE, Value.SymbolName);
934 addRelocationForSection(RE, Value.SectionID);
936 resolveRelocation(Section, Offset,
937 (uint64_t)Section.Address + Section.StubOffset,
939 Section.StubOffset += getMaxStubSize();
941 } else if ((Arch == Triple::mipsel || Arch == Triple::mips) &&
942 RelType == ELF::R_MIPS_26) {
943 // This is an Mips branch relocation, need to use a stub function.
944 DEBUG(dbgs() << "\t\tThis is a Mips branch relocation.");
945 SectionEntry &Section = Sections[SectionID];
946 uint8_t *Target = Section.Address + Offset;
947 uint32_t *TargetAddress = (uint32_t *)Target;
949 // Extract the addend from the instruction.
950 uint32_t Addend = ((*TargetAddress) & 0x03ffffff) << 2;
952 Value.Addend += Addend;
954 // Look up for existing stub.
955 StubMap::const_iterator i = Stubs.find(Value);
956 if (i != Stubs.end()) {
957 resolveRelocation(Section, Offset,
958 (uint64_t)Section.Address + i->second, RelType, 0);
959 DEBUG(dbgs() << " Stub function found\n");
961 // Create a new stub function.
962 DEBUG(dbgs() << " Create a new stub function\n");
963 Stubs[Value] = Section.StubOffset;
964 uint8_t *StubTargetAddr = createStubFunction(Section.Address +
967 // Creating Hi and Lo relocations for the filled stub instructions.
968 RelocationEntry REHi(SectionID,
969 StubTargetAddr - Section.Address,
970 ELF::R_MIPS_UNUSED1, Value.Addend);
971 RelocationEntry RELo(SectionID,
972 StubTargetAddr - Section.Address + 4,
973 ELF::R_MIPS_UNUSED2, Value.Addend);
975 if (Value.SymbolName) {
976 addRelocationForSymbol(REHi, Value.SymbolName);
977 addRelocationForSymbol(RELo, Value.SymbolName);
979 addRelocationForSection(REHi, Value.SectionID);
980 addRelocationForSection(RELo, Value.SectionID);
983 resolveRelocation(Section, Offset,
984 (uint64_t)Section.Address + Section.StubOffset,
986 Section.StubOffset += getMaxStubSize();
988 } else if (Arch == Triple::ppc64) {
989 if (RelType == ELF::R_PPC64_REL24) {
990 // A PPC branch relocation will need a stub function if the target is
991 // an external symbol (Symbol::ST_Unknown) or if the target address
992 // is not within the signed 24-bits branch address.
993 SectionEntry &Section = Sections[SectionID];
994 uint8_t *Target = Section.Address + Offset;
995 bool RangeOverflow = false;
996 if (SymType != SymbolRef::ST_Unknown) {
997 // A function call may points to the .opd entry, so the final symbol value
998 // in calculated based in the relocation values in .opd section.
999 findOPDEntrySection(Obj, ObjSectionToID, Value);
1000 uint8_t *RelocTarget = Sections[Value.SectionID].Address + Value.Addend;
1001 int32_t delta = static_cast<int32_t>(Target - RelocTarget);
1002 // If it is within 24-bits branch range, just set the branch target
1003 if (SignExtend32<24>(delta) == delta) {
1004 RelocationEntry RE(SectionID, Offset, RelType, Value.Addend);
1005 if (Value.SymbolName)
1006 addRelocationForSymbol(RE, Value.SymbolName);
1008 addRelocationForSection(RE, Value.SectionID);
1010 RangeOverflow = true;
1013 if (SymType == SymbolRef::ST_Unknown || RangeOverflow == true) {
1014 // It is an external symbol (SymbolRef::ST_Unknown) or within a range
1015 // larger than 24-bits.
1016 StubMap::const_iterator i = Stubs.find(Value);
1017 if (i != Stubs.end()) {
1018 // Symbol function stub already created, just relocate to it
1019 resolveRelocation(Section, Offset,
1020 (uint64_t)Section.Address + i->second, RelType, 0);
1021 DEBUG(dbgs() << " Stub function found\n");
1023 // Create a new stub function.
1024 DEBUG(dbgs() << " Create a new stub function\n");
1025 Stubs[Value] = Section.StubOffset;
1026 uint8_t *StubTargetAddr = createStubFunction(Section.Address +
1027 Section.StubOffset);
1028 RelocationEntry RE(SectionID, StubTargetAddr - Section.Address,
1029 ELF::R_PPC64_ADDR64, Value.Addend);
1031 // Generates the 64-bits address loads as exemplified in section
1032 // 4.5.1 in PPC64 ELF ABI.
1033 RelocationEntry REhst(SectionID,
1034 StubTargetAddr - Section.Address + 2,
1035 ELF::R_PPC64_ADDR16_HIGHEST, Value.Addend);
1036 RelocationEntry REhr(SectionID,
1037 StubTargetAddr - Section.Address + 6,
1038 ELF::R_PPC64_ADDR16_HIGHER, Value.Addend);
1039 RelocationEntry REh(SectionID,
1040 StubTargetAddr - Section.Address + 14,
1041 ELF::R_PPC64_ADDR16_HI, Value.Addend);
1042 RelocationEntry REl(SectionID,
1043 StubTargetAddr - Section.Address + 18,
1044 ELF::R_PPC64_ADDR16_LO, Value.Addend);
1046 if (Value.SymbolName) {
1047 addRelocationForSymbol(REhst, Value.SymbolName);
1048 addRelocationForSymbol(REhr, Value.SymbolName);
1049 addRelocationForSymbol(REh, Value.SymbolName);
1050 addRelocationForSymbol(REl, Value.SymbolName);
1052 addRelocationForSection(REhst, Value.SectionID);
1053 addRelocationForSection(REhr, Value.SectionID);
1054 addRelocationForSection(REh, Value.SectionID);
1055 addRelocationForSection(REl, Value.SectionID);
1058 resolveRelocation(Section, Offset,
1059 (uint64_t)Section.Address + Section.StubOffset,
1061 if (SymType == SymbolRef::ST_Unknown)
1062 // Restore the TOC for external calls
1063 writeInt32BE(Target+4, 0xE8410028); // ld r2,40(r1)
1064 Section.StubOffset += getMaxStubSize();
1068 RelocationEntry RE(SectionID, Offset, RelType, Value.Addend);
1069 // Extra check to avoid relocation againt empty symbols (usually
1070 // the R_PPC64_TOC).
1071 if (Value.SymbolName && !TargetName.empty())
1072 addRelocationForSymbol(RE, Value.SymbolName);
1074 addRelocationForSection(RE, Value.SectionID);
1076 } else if (Arch == Triple::systemz &&
1077 (RelType == ELF::R_390_PLT32DBL ||
1078 RelType == ELF::R_390_GOTENT)) {
1079 // Create function stubs for both PLT and GOT references, regardless of
1080 // whether the GOT reference is to data or code. The stub contains the
1081 // full address of the symbol, as needed by GOT references, and the
1082 // executable part only adds an overhead of 8 bytes.
1084 // We could try to conserve space by allocating the code and data
1085 // parts of the stub separately. However, as things stand, we allocate
1086 // a stub for every relocation, so using a GOT in JIT code should be
1087 // no less space efficient than using an explicit constant pool.
1088 DEBUG(dbgs() << "\t\tThis is a SystemZ indirect relocation.");
1089 SectionEntry &Section = Sections[SectionID];
1091 // Look for an existing stub.
1092 StubMap::const_iterator i = Stubs.find(Value);
1093 uintptr_t StubAddress;
1094 if (i != Stubs.end()) {
1095 StubAddress = uintptr_t(Section.Address) + i->second;
1096 DEBUG(dbgs() << " Stub function found\n");
1098 // Create a new stub function.
1099 DEBUG(dbgs() << " Create a new stub function\n");
1101 uintptr_t BaseAddress = uintptr_t(Section.Address);
1102 uintptr_t StubAlignment = getStubAlignment();
1103 StubAddress = (BaseAddress + Section.StubOffset +
1104 StubAlignment - 1) & -StubAlignment;
1105 unsigned StubOffset = StubAddress - BaseAddress;
1107 Stubs[Value] = StubOffset;
1108 createStubFunction((uint8_t *)StubAddress);
1109 RelocationEntry RE(SectionID, StubOffset + 8,
1110 ELF::R_390_64, Value.Addend - Addend);
1111 if (Value.SymbolName)
1112 addRelocationForSymbol(RE, Value.SymbolName);
1114 addRelocationForSection(RE, Value.SectionID);
1115 Section.StubOffset = StubOffset + getMaxStubSize();
1118 if (RelType == ELF::R_390_GOTENT)
1119 resolveRelocation(Section, Offset, StubAddress + 8,
1120 ELF::R_390_PC32DBL, Addend);
1122 resolveRelocation(Section, Offset, StubAddress, RelType, Addend);
1124 RelocationEntry RE(SectionID, Offset, RelType, Value.Addend);
1125 if (Value.SymbolName)
1126 addRelocationForSymbol(RE, Value.SymbolName);
1128 addRelocationForSection(RE, Value.SectionID);
1132 bool RuntimeDyldELF::isCompatibleFormat(const ObjectBuffer *Buffer) const {
1133 if (Buffer->getBufferSize() < strlen(ELF::ElfMagic))
1135 return (memcmp(Buffer->getBufferStart(), ELF::ElfMagic, strlen(ELF::ElfMagic))) == 0;