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 void RuntimeDyldELF::resolveARMRelocation(const SectionEntry &Section,
385 // TODO: Add Thumb relocations.
386 uint32_t *Placeholder = reinterpret_cast<uint32_t*>(Section.ObjAddress +
388 uint32_t* TargetPtr = (uint32_t*)(Section.Address + Offset);
389 uint32_t FinalAddress = ((Section.LoadAddress + Offset) & 0xFFFFFFFF);
392 DEBUG(dbgs() << "resolveARMRelocation, LocalAddress: "
393 << Section.Address + Offset
394 << " FinalAddress: " << format("%p",FinalAddress)
395 << " Value: " << format("%x",Value)
396 << " Type: " << format("%x",Type)
397 << " Addend: " << format("%x",Addend)
402 llvm_unreachable("Not implemented relocation type!");
404 // Write a 32bit value to relocation address, taking into account the
405 // implicit addend encoded in the target.
406 case ELF::R_ARM_TARGET1:
407 case ELF::R_ARM_ABS32:
408 *TargetPtr = *Placeholder + Value;
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 assert((*Placeholder & 0x000F0FFF) == 0);
417 Value = Value & 0xFFFF;
418 *TargetPtr = *Placeholder | (Value & 0xFFF);
419 *TargetPtr |= ((Value >> 12) & 0xF) << 16;
421 // Write last 16 bit of 32 bit value to the mov instruction.
422 // Last 4 bit should be shifted.
423 case ELF::R_ARM_MOVT_ABS:
424 // We are not expecting any other addend in the relocation address.
425 // Use 0x000F0FFF for the same reason as R_ARM_MOVW_ABS_NC.
426 assert((*Placeholder & 0x000F0FFF) == 0);
428 Value = (Value >> 16) & 0xFFFF;
429 *TargetPtr = *Placeholder | (Value & 0xFFF);
430 *TargetPtr |= ((Value >> 12) & 0xF) << 16;
432 // Write 24 bit relative value to the branch instruction.
433 case ELF::R_ARM_PC24 : // Fall through.
434 case ELF::R_ARM_CALL : // Fall through.
435 case ELF::R_ARM_JUMP24: {
436 int32_t RelValue = static_cast<int32_t>(Value - FinalAddress - 8);
437 RelValue = (RelValue & 0x03FFFFFC) >> 2;
438 assert((*TargetPtr & 0xFFFFFF) == 0xFFFFFE);
439 *TargetPtr &= 0xFF000000;
440 *TargetPtr |= RelValue;
443 case ELF::R_ARM_PRIVATE_0:
444 // This relocation is reserved by the ARM ELF ABI for internal use. We
445 // appropriate it here to act as an R_ARM_ABS32 without any addend for use
446 // in the stubs created during JIT (which can't put an addend into the
447 // original object file).
453 void RuntimeDyldELF::resolveMIPSRelocation(const SectionEntry &Section,
458 uint32_t* TargetPtr = (uint32_t*)(Section.Address + Offset);
461 DEBUG(dbgs() << "resolveMipselocation, LocalAddress: "
462 << Section.Address + Offset
464 << format("%p",Section.LoadAddress + Offset)
465 << " Value: " << format("%x",Value)
466 << " Type: " << format("%x",Type)
467 << " Addend: " << format("%x",Addend)
472 llvm_unreachable("Not implemented relocation type!");
475 *TargetPtr = Value + (*TargetPtr);
478 *TargetPtr = ((*TargetPtr) & 0xfc000000) | (( Value & 0x0fffffff) >> 2);
480 case ELF::R_MIPS_HI16:
481 // Get the higher 16-bits. Also add 1 if bit 15 is 1.
482 Value += ((*TargetPtr) & 0x0000ffff) << 16;
483 *TargetPtr = ((*TargetPtr) & 0xffff0000) |
484 (((Value + 0x8000) >> 16) & 0xffff);
486 case ELF::R_MIPS_LO16:
487 Value += ((*TargetPtr) & 0x0000ffff);
488 *TargetPtr = ((*TargetPtr) & 0xffff0000) | (Value & 0xffff);
493 // Return the .TOC. section address to R_PPC64_TOC relocations.
494 uint64_t RuntimeDyldELF::findPPC64TOC() const {
495 // The TOC consists of sections .got, .toc, .tocbss, .plt in that
496 // order. The TOC starts where the first of these sections starts.
497 SectionList::const_iterator it = Sections.begin();
498 SectionList::const_iterator ite = Sections.end();
499 for (; it != ite; ++it) {
500 if (it->Name == ".got" ||
501 it->Name == ".toc" ||
502 it->Name == ".tocbss" ||
507 // This may happen for
508 // * references to TOC base base (sym@toc, .odp relocation) without
510 // In this case just use the first section (which is usually
511 // the .odp) since the code won't reference the .toc base
513 it = Sections.begin();
516 // Per the ppc64-elf-linux ABI, The TOC base is TOC value plus 0x8000
517 // thus permitting a full 64 Kbytes segment.
518 return it->LoadAddress + 0x8000;
521 // Returns the sections and offset associated with the ODP entry referenced
523 void RuntimeDyldELF::findOPDEntrySection(ObjectImage &Obj,
524 ObjSectionToIDMap &LocalSections,
525 RelocationValueRef &Rel) {
526 // Get the ELF symbol value (st_value) to compare with Relocation offset in
530 for (section_iterator si = Obj.begin_sections(),
531 se = Obj.end_sections(); si != se; si.increment(err)) {
532 section_iterator RelSecI = si->getRelocatedSection();
533 if (RelSecI == Obj.end_sections())
536 StringRef RelSectionName;
537 check(RelSecI->getName(RelSectionName));
538 if (RelSectionName != ".opd")
541 for (relocation_iterator i = si->begin_relocations(),
542 e = si->end_relocations(); i != e;) {
545 // The R_PPC64_ADDR64 relocation indicates the first field
548 check(i->getType(TypeFunc));
549 if (TypeFunc != ELF::R_PPC64_ADDR64) {
554 SymbolRef TargetSymbol;
555 uint64_t TargetSymbolOffset;
556 check(i->getSymbol(TargetSymbol));
557 check(i->getOffset(TargetSymbolOffset));
559 check(getELFRelocationAddend(*i, Addend));
561 i = i.increment(err);
566 // Just check if following relocation is a R_PPC64_TOC
568 check(i->getType(TypeTOC));
569 if (TypeTOC != ELF::R_PPC64_TOC)
572 // Finally compares the Symbol value and the target symbol offset
573 // to check if this .opd entry refers to the symbol the relocation
575 if (Rel.Addend != (intptr_t)TargetSymbolOffset)
578 section_iterator tsi(Obj.end_sections());
579 check(TargetSymbol.getSection(tsi));
580 Rel.SectionID = findOrEmitSection(Obj, (*tsi), true, LocalSections);
581 Rel.Addend = (intptr_t)Addend;
585 llvm_unreachable("Attempting to get address of ODP entry!");
588 // Relocation masks following the #lo(value), #hi(value), #higher(value),
589 // and #highest(value) macros defined in section 4.5.1. Relocation Types
590 // in PPC-elf64abi document.
593 uint16_t applyPPClo (uint64_t value)
595 return value & 0xffff;
599 uint16_t applyPPChi (uint64_t value)
601 return (value >> 16) & 0xffff;
605 uint16_t applyPPChigher (uint64_t value)
607 return (value >> 32) & 0xffff;
611 uint16_t applyPPChighest (uint64_t value)
613 return (value >> 48) & 0xffff;
616 void RuntimeDyldELF::resolvePPC64Relocation(const SectionEntry &Section,
621 uint8_t* LocalAddress = Section.Address + Offset;
624 llvm_unreachable("Relocation type not implemented yet!");
626 case ELF::R_PPC64_ADDR16_LO :
627 writeInt16BE(LocalAddress, applyPPClo (Value + Addend));
629 case ELF::R_PPC64_ADDR16_HI :
630 writeInt16BE(LocalAddress, applyPPChi (Value + Addend));
632 case ELF::R_PPC64_ADDR16_HIGHER :
633 writeInt16BE(LocalAddress, applyPPChigher (Value + Addend));
635 case ELF::R_PPC64_ADDR16_HIGHEST :
636 writeInt16BE(LocalAddress, applyPPChighest (Value + Addend));
638 case ELF::R_PPC64_ADDR14 : {
639 assert(((Value + Addend) & 3) == 0);
640 // Preserve the AA/LK bits in the branch instruction
641 uint8_t aalk = *(LocalAddress+3);
642 writeInt16BE(LocalAddress + 2, (aalk & 3) | ((Value + Addend) & 0xfffc));
644 case ELF::R_PPC64_ADDR32 : {
645 int32_t Result = static_cast<int32_t>(Value + Addend);
646 if (SignExtend32<32>(Result) != Result)
647 llvm_unreachable("Relocation R_PPC64_ADDR32 overflow");
648 writeInt32BE(LocalAddress, Result);
650 case ELF::R_PPC64_REL24 : {
651 uint64_t FinalAddress = (Section.LoadAddress + Offset);
652 int32_t delta = static_cast<int32_t>(Value - FinalAddress + Addend);
653 if (SignExtend32<24>(delta) != delta)
654 llvm_unreachable("Relocation R_PPC64_REL24 overflow");
655 // Generates a 'bl <address>' instruction
656 writeInt32BE(LocalAddress, 0x48000001 | (delta & 0x03FFFFFC));
658 case ELF::R_PPC64_REL32 : {
659 uint64_t FinalAddress = (Section.LoadAddress + Offset);
660 int32_t delta = static_cast<int32_t>(Value - FinalAddress + Addend);
661 if (SignExtend32<32>(delta) != delta)
662 llvm_unreachable("Relocation R_PPC64_REL32 overflow");
663 writeInt32BE(LocalAddress, delta);
665 case ELF::R_PPC64_REL64: {
666 uint64_t FinalAddress = (Section.LoadAddress + Offset);
667 uint64_t Delta = Value - FinalAddress + Addend;
668 writeInt64BE(LocalAddress, Delta);
670 case ELF::R_PPC64_ADDR64 :
671 writeInt64BE(LocalAddress, Value + Addend);
673 case ELF::R_PPC64_TOC :
674 writeInt64BE(LocalAddress, findPPC64TOC());
676 case ELF::R_PPC64_TOC16 : {
677 uint64_t TOCStart = findPPC64TOC();
678 Value = applyPPClo((Value + Addend) - TOCStart);
679 writeInt16BE(LocalAddress, applyPPClo(Value));
681 case ELF::R_PPC64_TOC16_DS : {
682 uint64_t TOCStart = findPPC64TOC();
683 Value = ((Value + Addend) - TOCStart);
684 writeInt16BE(LocalAddress, applyPPClo(Value));
689 void RuntimeDyldELF::resolveSystemZRelocation(const SectionEntry &Section,
694 uint8_t *LocalAddress = Section.Address + Offset;
697 llvm_unreachable("Relocation type not implemented yet!");
699 case ELF::R_390_PC16DBL:
700 case ELF::R_390_PLT16DBL: {
701 int64_t Delta = (Value + Addend) - (Section.LoadAddress + Offset);
702 assert(int16_t(Delta / 2) * 2 == Delta && "R_390_PC16DBL overflow");
703 writeInt16BE(LocalAddress, Delta / 2);
706 case ELF::R_390_PC32DBL:
707 case ELF::R_390_PLT32DBL: {
708 int64_t Delta = (Value + Addend) - (Section.LoadAddress + Offset);
709 assert(int32_t(Delta / 2) * 2 == Delta && "R_390_PC32DBL overflow");
710 writeInt32BE(LocalAddress, Delta / 2);
713 case ELF::R_390_PC32: {
714 int64_t Delta = (Value + Addend) - (Section.LoadAddress + Offset);
715 assert(int32_t(Delta) == Delta && "R_390_PC32 overflow");
716 writeInt32BE(LocalAddress, Delta);
720 writeInt64BE(LocalAddress, Value + Addend);
725 void RuntimeDyldELF::resolveRelocation(const RelocationEntry &RE,
727 const SectionEntry &Section = Sections[RE.SectionID];
728 return resolveRelocation(Section, RE.Offset, Value, RE.RelType, RE.Addend);
731 void RuntimeDyldELF::resolveRelocation(const SectionEntry &Section,
738 resolveX86_64Relocation(Section, Offset, Value, Type, Addend);
741 resolveX86Relocation(Section, Offset,
742 (uint32_t)(Value & 0xffffffffL), Type,
743 (uint32_t)(Addend & 0xffffffffL));
745 case Triple::aarch64:
746 resolveAArch64Relocation(Section, Offset, Value, Type, Addend);
748 case Triple::arm: // Fall through.
750 resolveARMRelocation(Section, Offset,
751 (uint32_t)(Value & 0xffffffffL), Type,
752 (uint32_t)(Addend & 0xffffffffL));
754 case Triple::mips: // Fall through.
756 resolveMIPSRelocation(Section, Offset,
757 (uint32_t)(Value & 0xffffffffL), Type,
758 (uint32_t)(Addend & 0xffffffffL));
761 resolvePPC64Relocation(Section, Offset, Value, Type, Addend);
763 case Triple::systemz:
764 resolveSystemZRelocation(Section, Offset, Value, Type, Addend);
766 default: llvm_unreachable("Unsupported CPU type!");
770 void RuntimeDyldELF::processRelocationRef(unsigned SectionID,
773 ObjSectionToIDMap &ObjSectionToID,
774 const SymbolTableMap &Symbols,
777 Check(RelI.getType(RelType));
779 Check(getELFRelocationAddend(RelI, Addend));
781 Check(RelI.getSymbol(Symbol));
783 // Obtain the symbol name which is referenced in the relocation
784 StringRef TargetName;
785 Symbol.getName(TargetName);
786 DEBUG(dbgs() << "\t\tRelType: " << RelType
787 << " Addend: " << Addend
788 << " TargetName: " << TargetName
790 RelocationValueRef Value;
791 // First search for the symbol in the local symbol table
792 SymbolTableMap::const_iterator lsi = Symbols.find(TargetName.data());
793 SymbolRef::Type SymType;
794 Symbol.getType(SymType);
795 if (lsi != Symbols.end()) {
796 Value.SectionID = lsi->second.first;
797 Value.Addend = lsi->second.second + Addend;
799 // Search for the symbol in the global symbol table
800 SymbolTableMap::const_iterator gsi =
801 GlobalSymbolTable.find(TargetName.data());
802 if (gsi != GlobalSymbolTable.end()) {
803 Value.SectionID = gsi->second.first;
804 Value.Addend = gsi->second.second + Addend;
807 case SymbolRef::ST_Debug: {
808 // TODO: Now ELF SymbolRef::ST_Debug = STT_SECTION, it's not obviously
809 // and can be changed by another developers. Maybe best way is add
810 // a new symbol type ST_Section to SymbolRef and use it.
811 section_iterator si(Obj.end_sections());
812 Symbol.getSection(si);
813 if (si == Obj.end_sections())
814 llvm_unreachable("Symbol section not found, bad object file format!");
815 DEBUG(dbgs() << "\t\tThis is section symbol\n");
816 // Default to 'true' in case isText fails (though it never does).
819 Value.SectionID = findOrEmitSection(Obj,
823 Value.Addend = Addend;
826 case SymbolRef::ST_Unknown: {
827 Value.SymbolName = TargetName.data();
828 Value.Addend = Addend;
832 llvm_unreachable("Unresolved symbol type!");
838 Check(RelI.getOffset(Offset));
840 DEBUG(dbgs() << "\t\tSectionID: " << SectionID
841 << " Offset: " << Offset
843 if (Arch == Triple::aarch64 &&
844 (RelType == ELF::R_AARCH64_CALL26 ||
845 RelType == ELF::R_AARCH64_JUMP26)) {
846 // This is an AArch64 branch relocation, need to use a stub function.
847 DEBUG(dbgs() << "\t\tThis is an AArch64 branch relocation.");
848 SectionEntry &Section = Sections[SectionID];
850 // Look for an existing stub.
851 StubMap::const_iterator i = Stubs.find(Value);
852 if (i != Stubs.end()) {
853 resolveRelocation(Section, Offset,
854 (uint64_t)Section.Address + i->second, RelType, 0);
855 DEBUG(dbgs() << " Stub function found\n");
857 // Create a new stub function.
858 DEBUG(dbgs() << " Create a new stub function\n");
859 Stubs[Value] = Section.StubOffset;
860 uint8_t *StubTargetAddr = createStubFunction(Section.Address +
863 RelocationEntry REmovz_g3(SectionID,
864 StubTargetAddr - Section.Address,
865 ELF::R_AARCH64_MOVW_UABS_G3, Value.Addend);
866 RelocationEntry REmovk_g2(SectionID,
867 StubTargetAddr - Section.Address + 4,
868 ELF::R_AARCH64_MOVW_UABS_G2_NC, Value.Addend);
869 RelocationEntry REmovk_g1(SectionID,
870 StubTargetAddr - Section.Address + 8,
871 ELF::R_AARCH64_MOVW_UABS_G1_NC, Value.Addend);
872 RelocationEntry REmovk_g0(SectionID,
873 StubTargetAddr - Section.Address + 12,
874 ELF::R_AARCH64_MOVW_UABS_G0_NC, Value.Addend);
876 if (Value.SymbolName) {
877 addRelocationForSymbol(REmovz_g3, Value.SymbolName);
878 addRelocationForSymbol(REmovk_g2, Value.SymbolName);
879 addRelocationForSymbol(REmovk_g1, Value.SymbolName);
880 addRelocationForSymbol(REmovk_g0, Value.SymbolName);
882 addRelocationForSection(REmovz_g3, Value.SectionID);
883 addRelocationForSection(REmovk_g2, Value.SectionID);
884 addRelocationForSection(REmovk_g1, Value.SectionID);
885 addRelocationForSection(REmovk_g0, Value.SectionID);
887 resolveRelocation(Section, Offset,
888 (uint64_t)Section.Address + Section.StubOffset,
890 Section.StubOffset += getMaxStubSize();
892 } else if (Arch == Triple::arm &&
893 (RelType == ELF::R_ARM_PC24 ||
894 RelType == ELF::R_ARM_CALL ||
895 RelType == ELF::R_ARM_JUMP24)) {
896 // This is an ARM branch relocation, need to use a stub function.
897 DEBUG(dbgs() << "\t\tThis is an ARM branch relocation.");
898 SectionEntry &Section = Sections[SectionID];
900 // Look for an existing stub.
901 StubMap::const_iterator i = Stubs.find(Value);
902 if (i != Stubs.end()) {
903 resolveRelocation(Section, Offset,
904 (uint64_t)Section.Address + i->second, RelType, 0);
905 DEBUG(dbgs() << " Stub function found\n");
907 // Create a new stub function.
908 DEBUG(dbgs() << " Create a new stub function\n");
909 Stubs[Value] = Section.StubOffset;
910 uint8_t *StubTargetAddr = createStubFunction(Section.Address +
912 RelocationEntry RE(SectionID, StubTargetAddr - Section.Address,
913 ELF::R_ARM_PRIVATE_0, Value.Addend);
914 if (Value.SymbolName)
915 addRelocationForSymbol(RE, Value.SymbolName);
917 addRelocationForSection(RE, Value.SectionID);
919 resolveRelocation(Section, Offset,
920 (uint64_t)Section.Address + Section.StubOffset,
922 Section.StubOffset += getMaxStubSize();
924 } else if ((Arch == Triple::mipsel || Arch == Triple::mips) &&
925 RelType == ELF::R_MIPS_26) {
926 // This is an Mips branch relocation, need to use a stub function.
927 DEBUG(dbgs() << "\t\tThis is a Mips branch relocation.");
928 SectionEntry &Section = Sections[SectionID];
929 uint8_t *Target = Section.Address + Offset;
930 uint32_t *TargetAddress = (uint32_t *)Target;
932 // Extract the addend from the instruction.
933 uint32_t Addend = ((*TargetAddress) & 0x03ffffff) << 2;
935 Value.Addend += Addend;
937 // Look up for existing stub.
938 StubMap::const_iterator i = Stubs.find(Value);
939 if (i != Stubs.end()) {
940 resolveRelocation(Section, Offset,
941 (uint64_t)Section.Address + i->second, RelType, 0);
942 DEBUG(dbgs() << " Stub function found\n");
944 // Create a new stub function.
945 DEBUG(dbgs() << " Create a new stub function\n");
946 Stubs[Value] = Section.StubOffset;
947 uint8_t *StubTargetAddr = createStubFunction(Section.Address +
950 // Creating Hi and Lo relocations for the filled stub instructions.
951 RelocationEntry REHi(SectionID,
952 StubTargetAddr - Section.Address,
953 ELF::R_MIPS_HI16, Value.Addend);
954 RelocationEntry RELo(SectionID,
955 StubTargetAddr - Section.Address + 4,
956 ELF::R_MIPS_LO16, Value.Addend);
958 if (Value.SymbolName) {
959 addRelocationForSymbol(REHi, Value.SymbolName);
960 addRelocationForSymbol(RELo, Value.SymbolName);
962 addRelocationForSection(REHi, Value.SectionID);
963 addRelocationForSection(RELo, Value.SectionID);
966 resolveRelocation(Section, Offset,
967 (uint64_t)Section.Address + Section.StubOffset,
969 Section.StubOffset += getMaxStubSize();
971 } else if (Arch == Triple::ppc64) {
972 if (RelType == ELF::R_PPC64_REL24) {
973 // A PPC branch relocation will need a stub function if the target is
974 // an external symbol (Symbol::ST_Unknown) or if the target address
975 // is not within the signed 24-bits branch address.
976 SectionEntry &Section = Sections[SectionID];
977 uint8_t *Target = Section.Address + Offset;
978 bool RangeOverflow = false;
979 if (SymType != SymbolRef::ST_Unknown) {
980 // A function call may points to the .opd entry, so the final symbol value
981 // in calculated based in the relocation values in .opd section.
982 findOPDEntrySection(Obj, ObjSectionToID, Value);
983 uint8_t *RelocTarget = Sections[Value.SectionID].Address + Value.Addend;
984 int32_t delta = static_cast<int32_t>(Target - RelocTarget);
985 // If it is within 24-bits branch range, just set the branch target
986 if (SignExtend32<24>(delta) == delta) {
987 RelocationEntry RE(SectionID, Offset, RelType, Value.Addend);
988 if (Value.SymbolName)
989 addRelocationForSymbol(RE, Value.SymbolName);
991 addRelocationForSection(RE, Value.SectionID);
993 RangeOverflow = true;
996 if (SymType == SymbolRef::ST_Unknown || RangeOverflow == true) {
997 // It is an external symbol (SymbolRef::ST_Unknown) or within a range
998 // larger than 24-bits.
999 StubMap::const_iterator i = Stubs.find(Value);
1000 if (i != Stubs.end()) {
1001 // Symbol function stub already created, just relocate to it
1002 resolveRelocation(Section, Offset,
1003 (uint64_t)Section.Address + i->second, RelType, 0);
1004 DEBUG(dbgs() << " Stub function found\n");
1006 // Create a new stub function.
1007 DEBUG(dbgs() << " Create a new stub function\n");
1008 Stubs[Value] = Section.StubOffset;
1009 uint8_t *StubTargetAddr = createStubFunction(Section.Address +
1010 Section.StubOffset);
1011 RelocationEntry RE(SectionID, StubTargetAddr - Section.Address,
1012 ELF::R_PPC64_ADDR64, Value.Addend);
1014 // Generates the 64-bits address loads as exemplified in section
1015 // 4.5.1 in PPC64 ELF ABI.
1016 RelocationEntry REhst(SectionID,
1017 StubTargetAddr - Section.Address + 2,
1018 ELF::R_PPC64_ADDR16_HIGHEST, Value.Addend);
1019 RelocationEntry REhr(SectionID,
1020 StubTargetAddr - Section.Address + 6,
1021 ELF::R_PPC64_ADDR16_HIGHER, Value.Addend);
1022 RelocationEntry REh(SectionID,
1023 StubTargetAddr - Section.Address + 14,
1024 ELF::R_PPC64_ADDR16_HI, Value.Addend);
1025 RelocationEntry REl(SectionID,
1026 StubTargetAddr - Section.Address + 18,
1027 ELF::R_PPC64_ADDR16_LO, Value.Addend);
1029 if (Value.SymbolName) {
1030 addRelocationForSymbol(REhst, Value.SymbolName);
1031 addRelocationForSymbol(REhr, Value.SymbolName);
1032 addRelocationForSymbol(REh, Value.SymbolName);
1033 addRelocationForSymbol(REl, Value.SymbolName);
1035 addRelocationForSection(REhst, Value.SectionID);
1036 addRelocationForSection(REhr, Value.SectionID);
1037 addRelocationForSection(REh, Value.SectionID);
1038 addRelocationForSection(REl, Value.SectionID);
1041 resolveRelocation(Section, Offset,
1042 (uint64_t)Section.Address + Section.StubOffset,
1044 if (SymType == SymbolRef::ST_Unknown)
1045 // Restore the TOC for external calls
1046 writeInt32BE(Target+4, 0xE8410028); // ld r2,40(r1)
1047 Section.StubOffset += getMaxStubSize();
1051 RelocationEntry RE(SectionID, Offset, RelType, Value.Addend);
1052 // Extra check to avoid relocation againt empty symbols (usually
1053 // the R_PPC64_TOC).
1054 if (Value.SymbolName && !TargetName.empty())
1055 addRelocationForSymbol(RE, Value.SymbolName);
1057 addRelocationForSection(RE, Value.SectionID);
1059 } else if (Arch == Triple::systemz &&
1060 (RelType == ELF::R_390_PLT32DBL ||
1061 RelType == ELF::R_390_GOTENT)) {
1062 // Create function stubs for both PLT and GOT references, regardless of
1063 // whether the GOT reference is to data or code. The stub contains the
1064 // full address of the symbol, as needed by GOT references, and the
1065 // executable part only adds an overhead of 8 bytes.
1067 // We could try to conserve space by allocating the code and data
1068 // parts of the stub separately. However, as things stand, we allocate
1069 // a stub for every relocation, so using a GOT in JIT code should be
1070 // no less space efficient than using an explicit constant pool.
1071 DEBUG(dbgs() << "\t\tThis is a SystemZ indirect relocation.");
1072 SectionEntry &Section = Sections[SectionID];
1074 // Look for an existing stub.
1075 StubMap::const_iterator i = Stubs.find(Value);
1076 uintptr_t StubAddress;
1077 if (i != Stubs.end()) {
1078 StubAddress = uintptr_t(Section.Address) + i->second;
1079 DEBUG(dbgs() << " Stub function found\n");
1081 // Create a new stub function.
1082 DEBUG(dbgs() << " Create a new stub function\n");
1084 uintptr_t BaseAddress = uintptr_t(Section.Address);
1085 uintptr_t StubAlignment = getStubAlignment();
1086 StubAddress = (BaseAddress + Section.StubOffset +
1087 StubAlignment - 1) & -StubAlignment;
1088 unsigned StubOffset = StubAddress - BaseAddress;
1090 Stubs[Value] = StubOffset;
1091 createStubFunction((uint8_t *)StubAddress);
1092 RelocationEntry RE(SectionID, StubOffset + 8,
1093 ELF::R_390_64, Value.Addend - Addend);
1094 if (Value.SymbolName)
1095 addRelocationForSymbol(RE, Value.SymbolName);
1097 addRelocationForSection(RE, Value.SectionID);
1098 Section.StubOffset = StubOffset + getMaxStubSize();
1101 if (RelType == ELF::R_390_GOTENT)
1102 resolveRelocation(Section, Offset, StubAddress + 8,
1103 ELF::R_390_PC32DBL, Addend);
1105 resolveRelocation(Section, Offset, StubAddress, RelType, Addend);
1107 RelocationEntry RE(SectionID, Offset, RelType, Value.Addend);
1108 if (Value.SymbolName)
1109 addRelocationForSymbol(RE, Value.SymbolName);
1111 addRelocationForSection(RE, Value.SectionID);
1115 bool RuntimeDyldELF::isCompatibleFormat(const ObjectBuffer *Buffer) const {
1116 if (Buffer->getBufferSize() < strlen(ELF::ElfMagic))
1118 return (memcmp(Buffer->getBufferStart(), ELF::ElfMagic, strlen(ELF::ElfMagic))) == 0;