1 //===-- RuntimeDyldELF.cpp - Run-time dynamic linker for MC-JIT -*- C++ -*-===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // Implementation of ELF support for the MC-JIT runtime dynamic linker.
12 //===----------------------------------------------------------------------===//
14 #define DEBUG_TYPE "dyld"
15 #include "RuntimeDyldELF.h"
16 #include "JITRegistrar.h"
17 #include "ObjectImageCommon.h"
18 #include "llvm/ADT/IntervalMap.h"
19 #include "llvm/ADT/OwningPtr.h"
20 #include "llvm/ADT/STLExtras.h"
21 #include "llvm/ADT/StringRef.h"
22 #include "llvm/ADT/Triple.h"
23 #include "llvm/ExecutionEngine/ObjectBuffer.h"
24 #include "llvm/ExecutionEngine/ObjectImage.h"
25 #include "llvm/Object/ELFObjectFile.h"
26 #include "llvm/Object/ObjectFile.h"
27 #include "llvm/Support/ELF.h"
29 using namespace llvm::object;
34 error_code check(error_code Err) {
36 report_fatal_error(Err.message());
43 : public ELFObjectFile<ELFT> {
44 LLVM_ELF_IMPORT_TYPES_ELFT(ELFT)
46 typedef Elf_Shdr_Impl<ELFT> Elf_Shdr;
47 typedef Elf_Sym_Impl<ELFT> Elf_Sym;
49 Elf_Rel_Impl<ELFT, false> Elf_Rel;
51 Elf_Rel_Impl<ELFT, true> Elf_Rela;
53 typedef Elf_Ehdr_Impl<ELFT> Elf_Ehdr;
55 typedef typename ELFDataTypeTypedefHelper<
56 ELFT>::value_type addr_type;
59 DyldELFObject(MemoryBuffer *Wrapper, error_code &ec);
61 void updateSectionAddress(const SectionRef &Sec, uint64_t Addr);
62 void updateSymbolAddress(const SymbolRef &Sym, uint64_t Addr);
64 // Methods for type inquiry through isa, cast and dyn_cast
65 static inline bool classof(const Binary *v) {
66 return (isa<ELFObjectFile<ELFT> >(v)
67 && classof(cast<ELFObjectFile
70 static inline bool classof(
71 const ELFObjectFile<ELFT> *v) {
72 return v->isDyldType();
77 class ELFObjectImage : public ObjectImageCommon {
79 DyldELFObject<ELFT> *DyldObj;
83 ELFObjectImage(ObjectBuffer *Input,
84 DyldELFObject<ELFT> *Obj)
85 : ObjectImageCommon(Input, Obj),
89 virtual ~ELFObjectImage() {
91 deregisterWithDebugger();
94 // Subclasses can override these methods to update the image with loaded
95 // addresses for sections and common symbols
96 virtual void updateSectionAddress(const SectionRef &Sec, uint64_t Addr)
98 DyldObj->updateSectionAddress(Sec, Addr);
101 virtual void updateSymbolAddress(const SymbolRef &Sym, uint64_t Addr)
103 DyldObj->updateSymbolAddress(Sym, Addr);
106 virtual void registerWithDebugger()
108 JITRegistrar::getGDBRegistrar().registerObject(*Buffer);
111 virtual void deregisterWithDebugger()
113 JITRegistrar::getGDBRegistrar().deregisterObject(*Buffer);
117 // The MemoryBuffer passed into this constructor is just a wrapper around the
118 // actual memory. Ultimately, the Binary parent class will take ownership of
119 // this MemoryBuffer object but not the underlying memory.
121 DyldELFObject<ELFT>::DyldELFObject(MemoryBuffer *Wrapper, error_code &ec)
122 : ELFObjectFile<ELFT>(Wrapper, ec) {
123 this->isDyldELFObject = true;
127 void DyldELFObject<ELFT>::updateSectionAddress(const SectionRef &Sec,
129 DataRefImpl ShdrRef = Sec.getRawDataRefImpl();
130 Elf_Shdr *shdr = const_cast<Elf_Shdr*>(
131 reinterpret_cast<const Elf_Shdr *>(ShdrRef.p));
133 // This assumes the address passed in matches the target address bitness
134 // The template-based type cast handles everything else.
135 shdr->sh_addr = static_cast<addr_type>(Addr);
139 void DyldELFObject<ELFT>::updateSymbolAddress(const SymbolRef &SymRef,
142 Elf_Sym *sym = const_cast<Elf_Sym*>(
143 ELFObjectFile<ELFT>::getSymbol(SymRef.getRawDataRefImpl()));
145 // This assumes the address passed in matches the target address bitness
146 // The template-based type cast handles everything else.
147 sym->st_value = static_cast<addr_type>(Addr);
154 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 &= 0xffe0001fU;
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;
344 // AArch64 code is emitted with .rela relocations. The data already in any
345 // bits affected by the relocation on entry is garbage.
346 *TargetPtr &= 0xffe0001fU;
347 // Immediate goes in bits 20:5 of MOVZ/MOVK instruction
348 *TargetPtr |= ((Result & 0xffff00000000ULL) >> (32 - 5));
349 // Shift must be "lsl #32", in bits 22:21
350 assert((*TargetPtr >> 21 & 0x3) == 2 && "invalid shift for relocation");
353 case ELF::R_AARCH64_MOVW_UABS_G1_NC: {
354 uint64_t Result = Value + Addend;
356 // AArch64 code is emitted with .rela relocations. The data already in any
357 // bits affected by the relocation on entry is garbage.
358 *TargetPtr &= 0xffe0001fU;
359 // Immediate goes in bits 20:5 of MOVZ/MOVK instruction
360 *TargetPtr |= ((Result & 0xffff0000U) >> (16 - 5));
361 // Shift must be "lsl #16", in bits 22:2
362 assert((*TargetPtr >> 21 & 0x3) == 1 && "invalid shift for relocation");
365 case ELF::R_AARCH64_MOVW_UABS_G0_NC: {
366 uint64_t Result = Value + Addend;
368 // AArch64 code is emitted with .rela relocations. The data already in any
369 // bits affected by the relocation on entry is garbage.
370 *TargetPtr &= 0xffe0001fU;
371 // Immediate goes in bits 20:5 of MOVZ/MOVK instruction
372 *TargetPtr |= ((Result & 0xffffU) << 5);
373 // Shift must be "lsl #0", in bits 22:21.
374 assert((*TargetPtr >> 21 & 0x3) == 0 && "invalid shift for relocation");
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 *Placeholder = reinterpret_cast<uint32_t*>(Section.ObjAddress +
460 uint32_t* TargetPtr = (uint32_t*)(Section.Address + Offset);
463 DEBUG(dbgs() << "resolveMipselocation, LocalAddress: "
464 << Section.Address + Offset
466 << format("%p",Section.LoadAddress + Offset)
467 << " Value: " << format("%x",Value)
468 << " Type: " << format("%x",Type)
469 << " Addend: " << format("%x",Addend)
474 llvm_unreachable("Not implemented relocation type!");
477 *TargetPtr = Value + (*Placeholder);
480 *TargetPtr = ((*Placeholder) & 0xfc000000) | (( Value & 0x0fffffff) >> 2);
482 case ELF::R_MIPS_HI16:
483 // Get the higher 16-bits. Also add 1 if bit 15 is 1.
484 Value += ((*Placeholder) & 0x0000ffff) << 16;
485 *TargetPtr = ((*Placeholder) & 0xffff0000) |
486 (((Value + 0x8000) >> 16) & 0xffff);
488 case ELF::R_MIPS_LO16:
489 Value += ((*Placeholder) & 0x0000ffff);
490 *TargetPtr = ((*Placeholder) & 0xffff0000) | (Value & 0xffff);
492 case ELF::R_MIPS_UNUSED1:
493 // Similar to ELF::R_ARM_PRIVATE_0, R_MIPS_UNUSED1 and R_MIPS_UNUSED2
494 // are used for internal JIT purpose. These relocations are similar to
495 // R_MIPS_HI16 and R_MIPS_LO16, but they do not take any addend into
497 *TargetPtr = ((*TargetPtr) & 0xffff0000) |
498 (((Value + 0x8000) >> 16) & 0xffff);
500 case ELF::R_MIPS_UNUSED2:
501 *TargetPtr = ((*TargetPtr) & 0xffff0000) | (Value & 0xffff);
506 // Return the .TOC. section address to R_PPC64_TOC relocations.
507 uint64_t RuntimeDyldELF::findPPC64TOC() const {
508 // The TOC consists of sections .got, .toc, .tocbss, .plt in that
509 // order. The TOC starts where the first of these sections starts.
510 SectionList::const_iterator it = Sections.begin();
511 SectionList::const_iterator ite = Sections.end();
512 for (; it != ite; ++it) {
513 if (it->Name == ".got" ||
514 it->Name == ".toc" ||
515 it->Name == ".tocbss" ||
520 // This may happen for
521 // * references to TOC base base (sym@toc, .odp relocation) without
523 // In this case just use the first section (which is usually
524 // the .odp) since the code won't reference the .toc base
526 it = Sections.begin();
529 // Per the ppc64-elf-linux ABI, The TOC base is TOC value plus 0x8000
530 // thus permitting a full 64 Kbytes segment.
531 return it->LoadAddress + 0x8000;
534 // Returns the sections and offset associated with the ODP entry referenced
536 void RuntimeDyldELF::findOPDEntrySection(ObjectImage &Obj,
537 ObjSectionToIDMap &LocalSections,
538 RelocationValueRef &Rel) {
539 // Get the ELF symbol value (st_value) to compare with Relocation offset in
543 for (section_iterator si = Obj.begin_sections(),
544 se = Obj.end_sections(); si != se; si.increment(err)) {
545 section_iterator RelSecI = si->getRelocatedSection();
546 if (RelSecI == Obj.end_sections())
549 StringRef RelSectionName;
550 check(RelSecI->getName(RelSectionName));
551 if (RelSectionName != ".opd")
554 for (relocation_iterator i = si->begin_relocations(),
555 e = si->end_relocations(); i != e;) {
558 // The R_PPC64_ADDR64 relocation indicates the first field
561 check(i->getType(TypeFunc));
562 if (TypeFunc != ELF::R_PPC64_ADDR64) {
567 uint64_t TargetSymbolOffset;
568 symbol_iterator TargetSymbol = i->getSymbol();
569 check(i->getOffset(TargetSymbolOffset));
571 check(getELFRelocationAddend(*i, Addend));
573 i = i.increment(err);
578 // Just check if following relocation is a R_PPC64_TOC
580 check(i->getType(TypeTOC));
581 if (TypeTOC != ELF::R_PPC64_TOC)
584 // Finally compares the Symbol value and the target symbol offset
585 // to check if this .opd entry refers to the symbol the relocation
587 if (Rel.Addend != (intptr_t)TargetSymbolOffset)
590 section_iterator tsi(Obj.end_sections());
591 check(TargetSymbol->getSection(tsi));
592 Rel.SectionID = findOrEmitSection(Obj, (*tsi), true, LocalSections);
593 Rel.Addend = (intptr_t)Addend;
597 llvm_unreachable("Attempting to get address of ODP entry!");
600 // Relocation masks following the #lo(value), #hi(value), #higher(value),
601 // and #highest(value) macros defined in section 4.5.1. Relocation Types
602 // in PPC-elf64abi document.
605 uint16_t applyPPClo (uint64_t value)
607 return value & 0xffff;
611 uint16_t applyPPChi (uint64_t value)
613 return (value >> 16) & 0xffff;
617 uint16_t applyPPChigher (uint64_t value)
619 return (value >> 32) & 0xffff;
623 uint16_t applyPPChighest (uint64_t value)
625 return (value >> 48) & 0xffff;
628 void RuntimeDyldELF::resolvePPC64Relocation(const SectionEntry &Section,
633 uint8_t* LocalAddress = Section.Address + Offset;
636 llvm_unreachable("Relocation type not implemented yet!");
638 case ELF::R_PPC64_ADDR16_LO :
639 writeInt16BE(LocalAddress, applyPPClo (Value + Addend));
641 case ELF::R_PPC64_ADDR16_HI :
642 writeInt16BE(LocalAddress, applyPPChi (Value + Addend));
644 case ELF::R_PPC64_ADDR16_HIGHER :
645 writeInt16BE(LocalAddress, applyPPChigher (Value + Addend));
647 case ELF::R_PPC64_ADDR16_HIGHEST :
648 writeInt16BE(LocalAddress, applyPPChighest (Value + Addend));
650 case ELF::R_PPC64_ADDR14 : {
651 assert(((Value + Addend) & 3) == 0);
652 // Preserve the AA/LK bits in the branch instruction
653 uint8_t aalk = *(LocalAddress+3);
654 writeInt16BE(LocalAddress + 2, (aalk & 3) | ((Value + Addend) & 0xfffc));
656 case ELF::R_PPC64_ADDR32 : {
657 int32_t Result = static_cast<int32_t>(Value + Addend);
658 if (SignExtend32<32>(Result) != Result)
659 llvm_unreachable("Relocation R_PPC64_ADDR32 overflow");
660 writeInt32BE(LocalAddress, Result);
662 case ELF::R_PPC64_REL24 : {
663 uint64_t FinalAddress = (Section.LoadAddress + Offset);
664 int32_t delta = static_cast<int32_t>(Value - FinalAddress + Addend);
665 if (SignExtend32<24>(delta) != delta)
666 llvm_unreachable("Relocation R_PPC64_REL24 overflow");
667 // Generates a 'bl <address>' instruction
668 writeInt32BE(LocalAddress, 0x48000001 | (delta & 0x03FFFFFC));
670 case ELF::R_PPC64_REL32 : {
671 uint64_t FinalAddress = (Section.LoadAddress + Offset);
672 int32_t delta = static_cast<int32_t>(Value - FinalAddress + Addend);
673 if (SignExtend32<32>(delta) != delta)
674 llvm_unreachable("Relocation R_PPC64_REL32 overflow");
675 writeInt32BE(LocalAddress, delta);
677 case ELF::R_PPC64_REL64: {
678 uint64_t FinalAddress = (Section.LoadAddress + Offset);
679 uint64_t Delta = Value - FinalAddress + Addend;
680 writeInt64BE(LocalAddress, Delta);
682 case ELF::R_PPC64_ADDR64 :
683 writeInt64BE(LocalAddress, Value + Addend);
685 case ELF::R_PPC64_TOC :
686 writeInt64BE(LocalAddress, findPPC64TOC());
688 case ELF::R_PPC64_TOC16 : {
689 uint64_t TOCStart = findPPC64TOC();
690 Value = applyPPClo((Value + Addend) - TOCStart);
691 writeInt16BE(LocalAddress, applyPPClo(Value));
693 case ELF::R_PPC64_TOC16_DS : {
694 uint64_t TOCStart = findPPC64TOC();
695 Value = ((Value + Addend) - TOCStart);
696 writeInt16BE(LocalAddress, applyPPClo(Value));
701 void RuntimeDyldELF::resolveSystemZRelocation(const SectionEntry &Section,
706 uint8_t *LocalAddress = Section.Address + Offset;
709 llvm_unreachable("Relocation type not implemented yet!");
711 case ELF::R_390_PC16DBL:
712 case ELF::R_390_PLT16DBL: {
713 int64_t Delta = (Value + Addend) - (Section.LoadAddress + Offset);
714 assert(int16_t(Delta / 2) * 2 == Delta && "R_390_PC16DBL overflow");
715 writeInt16BE(LocalAddress, Delta / 2);
718 case ELF::R_390_PC32DBL:
719 case ELF::R_390_PLT32DBL: {
720 int64_t Delta = (Value + Addend) - (Section.LoadAddress + Offset);
721 assert(int32_t(Delta / 2) * 2 == Delta && "R_390_PC32DBL overflow");
722 writeInt32BE(LocalAddress, Delta / 2);
725 case ELF::R_390_PC32: {
726 int64_t Delta = (Value + Addend) - (Section.LoadAddress + Offset);
727 assert(int32_t(Delta) == Delta && "R_390_PC32 overflow");
728 writeInt32BE(LocalAddress, Delta);
732 writeInt64BE(LocalAddress, Value + Addend);
737 void RuntimeDyldELF::resolveRelocation(const RelocationEntry &RE,
739 const SectionEntry &Section = Sections[RE.SectionID];
740 return resolveRelocation(Section, RE.Offset, Value, RE.RelType, RE.Addend);
743 void RuntimeDyldELF::resolveRelocation(const SectionEntry &Section,
750 resolveX86_64Relocation(Section, Offset, Value, Type, Addend);
753 resolveX86Relocation(Section, Offset,
754 (uint32_t)(Value & 0xffffffffL), Type,
755 (uint32_t)(Addend & 0xffffffffL));
757 case Triple::aarch64:
758 resolveAArch64Relocation(Section, Offset, Value, Type, Addend);
760 case Triple::arm: // Fall through.
762 resolveARMRelocation(Section, Offset,
763 (uint32_t)(Value & 0xffffffffL), Type,
764 (uint32_t)(Addend & 0xffffffffL));
766 case Triple::mips: // Fall through.
768 resolveMIPSRelocation(Section, Offset,
769 (uint32_t)(Value & 0xffffffffL), Type,
770 (uint32_t)(Addend & 0xffffffffL));
772 case Triple::ppc64: // Fall through.
773 case Triple::ppc64le:
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;
847 // Absolute relocations will have a zero symbol ID (STN_UNDEF), which
848 // will manifest here as a NULL symbol name.
849 // We can set this as a valid (but empty) symbol name, and rely
850 // on addRelocationForSymbol to handle this.
851 if (!Value.SymbolName)
852 Value.SymbolName = "";
856 llvm_unreachable("Unresolved symbol type!");
862 Check(RelI.getOffset(Offset));
864 DEBUG(dbgs() << "\t\tSectionID: " << SectionID
865 << " Offset: " << Offset
867 if (Arch == Triple::aarch64 &&
868 (RelType == ELF::R_AARCH64_CALL26 ||
869 RelType == ELF::R_AARCH64_JUMP26)) {
870 // This is an AArch64 branch relocation, need to use a stub function.
871 DEBUG(dbgs() << "\t\tThis is an AArch64 branch relocation.");
872 SectionEntry &Section = Sections[SectionID];
874 // Look for an existing stub.
875 StubMap::const_iterator i = Stubs.find(Value);
876 if (i != Stubs.end()) {
877 resolveRelocation(Section, Offset,
878 (uint64_t)Section.Address + i->second, RelType, 0);
879 DEBUG(dbgs() << " Stub function found\n");
881 // Create a new stub function.
882 DEBUG(dbgs() << " Create a new stub function\n");
883 Stubs[Value] = Section.StubOffset;
884 uint8_t *StubTargetAddr = createStubFunction(Section.Address +
887 RelocationEntry REmovz_g3(SectionID,
888 StubTargetAddr - Section.Address,
889 ELF::R_AARCH64_MOVW_UABS_G3, Value.Addend);
890 RelocationEntry REmovk_g2(SectionID,
891 StubTargetAddr - Section.Address + 4,
892 ELF::R_AARCH64_MOVW_UABS_G2_NC, Value.Addend);
893 RelocationEntry REmovk_g1(SectionID,
894 StubTargetAddr - Section.Address + 8,
895 ELF::R_AARCH64_MOVW_UABS_G1_NC, Value.Addend);
896 RelocationEntry REmovk_g0(SectionID,
897 StubTargetAddr - Section.Address + 12,
898 ELF::R_AARCH64_MOVW_UABS_G0_NC, Value.Addend);
900 if (Value.SymbolName) {
901 addRelocationForSymbol(REmovz_g3, Value.SymbolName);
902 addRelocationForSymbol(REmovk_g2, Value.SymbolName);
903 addRelocationForSymbol(REmovk_g1, Value.SymbolName);
904 addRelocationForSymbol(REmovk_g0, Value.SymbolName);
906 addRelocationForSection(REmovz_g3, Value.SectionID);
907 addRelocationForSection(REmovk_g2, Value.SectionID);
908 addRelocationForSection(REmovk_g1, Value.SectionID);
909 addRelocationForSection(REmovk_g0, Value.SectionID);
911 resolveRelocation(Section, Offset,
912 (uint64_t)Section.Address + Section.StubOffset,
914 Section.StubOffset += getMaxStubSize();
916 } else if (Arch == Triple::arm &&
917 (RelType == ELF::R_ARM_PC24 ||
918 RelType == ELF::R_ARM_CALL ||
919 RelType == ELF::R_ARM_JUMP24)) {
920 // This is an ARM branch relocation, need to use a stub function.
921 DEBUG(dbgs() << "\t\tThis is an ARM branch relocation.");
922 SectionEntry &Section = Sections[SectionID];
924 // Look for an existing stub.
925 StubMap::const_iterator i = Stubs.find(Value);
926 if (i != Stubs.end()) {
927 resolveRelocation(Section, Offset,
928 (uint64_t)Section.Address + i->second, RelType, 0);
929 DEBUG(dbgs() << " Stub function found\n");
931 // Create a new stub function.
932 DEBUG(dbgs() << " Create a new stub function\n");
933 Stubs[Value] = Section.StubOffset;
934 uint8_t *StubTargetAddr = createStubFunction(Section.Address +
936 RelocationEntry RE(SectionID, StubTargetAddr - Section.Address,
937 ELF::R_ARM_PRIVATE_0, Value.Addend);
938 if (Value.SymbolName)
939 addRelocationForSymbol(RE, Value.SymbolName);
941 addRelocationForSection(RE, Value.SectionID);
943 resolveRelocation(Section, Offset,
944 (uint64_t)Section.Address + Section.StubOffset,
946 Section.StubOffset += getMaxStubSize();
948 } else if ((Arch == Triple::mipsel || Arch == Triple::mips) &&
949 RelType == ELF::R_MIPS_26) {
950 // This is an Mips branch relocation, need to use a stub function.
951 DEBUG(dbgs() << "\t\tThis is a Mips branch relocation.");
952 SectionEntry &Section = Sections[SectionID];
953 uint8_t *Target = Section.Address + Offset;
954 uint32_t *TargetAddress = (uint32_t *)Target;
956 // Extract the addend from the instruction.
957 uint32_t Addend = ((*TargetAddress) & 0x03ffffff) << 2;
959 Value.Addend += Addend;
961 // Look up for existing stub.
962 StubMap::const_iterator i = Stubs.find(Value);
963 if (i != Stubs.end()) {
964 resolveRelocation(Section, Offset,
965 (uint64_t)Section.Address + i->second, RelType, 0);
966 DEBUG(dbgs() << " Stub function found\n");
968 // Create a new stub function.
969 DEBUG(dbgs() << " Create a new stub function\n");
970 Stubs[Value] = Section.StubOffset;
971 uint8_t *StubTargetAddr = createStubFunction(Section.Address +
974 // Creating Hi and Lo relocations for the filled stub instructions.
975 RelocationEntry REHi(SectionID,
976 StubTargetAddr - Section.Address,
977 ELF::R_MIPS_UNUSED1, Value.Addend);
978 RelocationEntry RELo(SectionID,
979 StubTargetAddr - Section.Address + 4,
980 ELF::R_MIPS_UNUSED2, Value.Addend);
982 if (Value.SymbolName) {
983 addRelocationForSymbol(REHi, Value.SymbolName);
984 addRelocationForSymbol(RELo, Value.SymbolName);
986 addRelocationForSection(REHi, Value.SectionID);
987 addRelocationForSection(RELo, Value.SectionID);
990 resolveRelocation(Section, Offset,
991 (uint64_t)Section.Address + Section.StubOffset,
993 Section.StubOffset += getMaxStubSize();
995 } else if (Arch == Triple::ppc64 || Arch == Triple::ppc64le) {
996 if (RelType == ELF::R_PPC64_REL24) {
997 // A PPC branch relocation will need a stub function if the target is
998 // an external symbol (Symbol::ST_Unknown) or if the target address
999 // is not within the signed 24-bits branch address.
1000 SectionEntry &Section = Sections[SectionID];
1001 uint8_t *Target = Section.Address + Offset;
1002 bool RangeOverflow = false;
1003 if (SymType != SymbolRef::ST_Unknown) {
1004 // A function call may points to the .opd entry, so the final symbol value
1005 // in calculated based in the relocation values in .opd section.
1006 findOPDEntrySection(Obj, ObjSectionToID, Value);
1007 uint8_t *RelocTarget = Sections[Value.SectionID].Address + Value.Addend;
1008 int32_t delta = static_cast<int32_t>(Target - RelocTarget);
1009 // If it is within 24-bits branch range, just set the branch target
1010 if (SignExtend32<24>(delta) == delta) {
1011 RelocationEntry RE(SectionID, Offset, RelType, Value.Addend);
1012 if (Value.SymbolName)
1013 addRelocationForSymbol(RE, Value.SymbolName);
1015 addRelocationForSection(RE, Value.SectionID);
1017 RangeOverflow = true;
1020 if (SymType == SymbolRef::ST_Unknown || RangeOverflow == true) {
1021 // It is an external symbol (SymbolRef::ST_Unknown) or within a range
1022 // larger than 24-bits.
1023 StubMap::const_iterator i = Stubs.find(Value);
1024 if (i != Stubs.end()) {
1025 // Symbol function stub already created, just relocate to it
1026 resolveRelocation(Section, Offset,
1027 (uint64_t)Section.Address + i->second, RelType, 0);
1028 DEBUG(dbgs() << " Stub function found\n");
1030 // Create a new stub function.
1031 DEBUG(dbgs() << " Create a new stub function\n");
1032 Stubs[Value] = Section.StubOffset;
1033 uint8_t *StubTargetAddr = createStubFunction(Section.Address +
1034 Section.StubOffset);
1035 RelocationEntry RE(SectionID, StubTargetAddr - Section.Address,
1036 ELF::R_PPC64_ADDR64, Value.Addend);
1038 // Generates the 64-bits address loads as exemplified in section
1039 // 4.5.1 in PPC64 ELF ABI.
1040 RelocationEntry REhst(SectionID,
1041 StubTargetAddr - Section.Address + 2,
1042 ELF::R_PPC64_ADDR16_HIGHEST, Value.Addend);
1043 RelocationEntry REhr(SectionID,
1044 StubTargetAddr - Section.Address + 6,
1045 ELF::R_PPC64_ADDR16_HIGHER, Value.Addend);
1046 RelocationEntry REh(SectionID,
1047 StubTargetAddr - Section.Address + 14,
1048 ELF::R_PPC64_ADDR16_HI, Value.Addend);
1049 RelocationEntry REl(SectionID,
1050 StubTargetAddr - Section.Address + 18,
1051 ELF::R_PPC64_ADDR16_LO, Value.Addend);
1053 if (Value.SymbolName) {
1054 addRelocationForSymbol(REhst, Value.SymbolName);
1055 addRelocationForSymbol(REhr, Value.SymbolName);
1056 addRelocationForSymbol(REh, Value.SymbolName);
1057 addRelocationForSymbol(REl, Value.SymbolName);
1059 addRelocationForSection(REhst, Value.SectionID);
1060 addRelocationForSection(REhr, Value.SectionID);
1061 addRelocationForSection(REh, Value.SectionID);
1062 addRelocationForSection(REl, Value.SectionID);
1065 resolveRelocation(Section, Offset,
1066 (uint64_t)Section.Address + Section.StubOffset,
1068 if (SymType == SymbolRef::ST_Unknown)
1069 // Restore the TOC for external calls
1070 writeInt32BE(Target+4, 0xE8410028); // ld r2,40(r1)
1071 Section.StubOffset += getMaxStubSize();
1075 RelocationEntry RE(SectionID, Offset, RelType, Value.Addend);
1076 // Extra check to avoid relocation againt empty symbols (usually
1077 // the R_PPC64_TOC).
1078 if (SymType != SymbolRef::ST_Unknown && TargetName.empty())
1079 Value.SymbolName = NULL;
1081 if (Value.SymbolName)
1082 addRelocationForSymbol(RE, Value.SymbolName);
1084 addRelocationForSection(RE, Value.SectionID);
1086 } else if (Arch == Triple::systemz &&
1087 (RelType == ELF::R_390_PLT32DBL ||
1088 RelType == ELF::R_390_GOTENT)) {
1089 // Create function stubs for both PLT and GOT references, regardless of
1090 // whether the GOT reference is to data or code. The stub contains the
1091 // full address of the symbol, as needed by GOT references, and the
1092 // executable part only adds an overhead of 8 bytes.
1094 // We could try to conserve space by allocating the code and data
1095 // parts of the stub separately. However, as things stand, we allocate
1096 // a stub for every relocation, so using a GOT in JIT code should be
1097 // no less space efficient than using an explicit constant pool.
1098 DEBUG(dbgs() << "\t\tThis is a SystemZ indirect relocation.");
1099 SectionEntry &Section = Sections[SectionID];
1101 // Look for an existing stub.
1102 StubMap::const_iterator i = Stubs.find(Value);
1103 uintptr_t StubAddress;
1104 if (i != Stubs.end()) {
1105 StubAddress = uintptr_t(Section.Address) + i->second;
1106 DEBUG(dbgs() << " Stub function found\n");
1108 // Create a new stub function.
1109 DEBUG(dbgs() << " Create a new stub function\n");
1111 uintptr_t BaseAddress = uintptr_t(Section.Address);
1112 uintptr_t StubAlignment = getStubAlignment();
1113 StubAddress = (BaseAddress + Section.StubOffset +
1114 StubAlignment - 1) & -StubAlignment;
1115 unsigned StubOffset = StubAddress - BaseAddress;
1117 Stubs[Value] = StubOffset;
1118 createStubFunction((uint8_t *)StubAddress);
1119 RelocationEntry RE(SectionID, StubOffset + 8,
1120 ELF::R_390_64, Value.Addend - Addend);
1121 if (Value.SymbolName)
1122 addRelocationForSymbol(RE, Value.SymbolName);
1124 addRelocationForSection(RE, Value.SectionID);
1125 Section.StubOffset = StubOffset + getMaxStubSize();
1128 if (RelType == ELF::R_390_GOTENT)
1129 resolveRelocation(Section, Offset, StubAddress + 8,
1130 ELF::R_390_PC32DBL, Addend);
1132 resolveRelocation(Section, Offset, StubAddress, RelType, Addend);
1134 RelocationEntry RE(SectionID, Offset, RelType, Value.Addend);
1135 if (Value.SymbolName)
1136 addRelocationForSymbol(RE, Value.SymbolName);
1138 addRelocationForSection(RE, Value.SectionID);
1142 bool RuntimeDyldELF::isCompatibleFormat(const ObjectBuffer *Buffer) const {
1143 if (Buffer->getBufferSize() < strlen(ELF::ElfMagic))
1145 return (memcmp(Buffer->getBufferStart(), ELF::ElfMagic, strlen(ELF::ElfMagic))) == 0;