1 //===-- RuntimeDyld.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 the MC-JIT runtime dynamic linker.
12 //===----------------------------------------------------------------------===//
14 #include "llvm/ExecutionEngine/RuntimeDyld.h"
15 #include "JITRegistrar.h"
16 #include "ObjectImageCommon.h"
17 #include "RuntimeDyldCheckerImpl.h"
18 #include "RuntimeDyldELF.h"
19 #include "RuntimeDyldImpl.h"
20 #include "RuntimeDyldMachO.h"
21 #include "llvm/Object/ELF.h"
22 #include "llvm/Support/MathExtras.h"
23 #include "llvm/Support/MutexGuard.h"
26 using namespace llvm::object;
28 #define DEBUG_TYPE "dyld"
30 // Empty out-of-line virtual destructor as the key function.
31 RuntimeDyldImpl::~RuntimeDyldImpl() {}
33 // Pin the JITRegistrar's and ObjectImage*'s vtables to this file.
34 void JITRegistrar::anchor() {}
35 void ObjectImage::anchor() {}
36 void ObjectImageCommon::anchor() {}
40 void RuntimeDyldImpl::registerEHFrames() {}
42 void RuntimeDyldImpl::deregisterEHFrames() {}
44 // Resolve the relocations for all symbols we currently know about.
45 void RuntimeDyldImpl::resolveRelocations() {
46 MutexGuard locked(lock);
48 // First, resolve relocations associated with external symbols.
49 resolveExternalSymbols();
51 // Just iterate over the sections we have and resolve all the relocations
52 // in them. Gross overkill, but it gets the job done.
53 for (int i = 0, e = Sections.size(); i != e; ++i) {
54 // The Section here (Sections[i]) refers to the section in which the
55 // symbol for the relocation is located. The SectionID in the relocation
56 // entry provides the section to which the relocation will be applied.
57 uint64_t Addr = Sections[i].LoadAddress;
58 DEBUG(dbgs() << "Resolving relocations Section #" << i << "\t"
59 << format("%p", (uint8_t *)Addr) << "\n");
60 resolveRelocationList(Relocations[i], Addr);
65 void RuntimeDyldImpl::mapSectionAddress(const void *LocalAddress,
66 uint64_t TargetAddress) {
67 MutexGuard locked(lock);
68 for (unsigned i = 0, e = Sections.size(); i != e; ++i) {
69 if (Sections[i].Address == LocalAddress) {
70 reassignSectionAddress(i, TargetAddress);
74 llvm_unreachable("Attempting to remap address of unknown section!");
77 static std::error_code getOffset(const SymbolRef &Sym, uint64_t &Result) {
79 if (std::error_code EC = Sym.getAddress(Address))
82 if (Address == UnknownAddressOrSize) {
83 Result = UnknownAddressOrSize;
84 return object_error::success;
87 const ObjectFile *Obj = Sym.getObject();
88 section_iterator SecI(Obj->section_begin());
89 if (std::error_code EC = Sym.getSection(SecI))
92 if (SecI == Obj->section_end()) {
93 Result = UnknownAddressOrSize;
94 return object_error::success;
97 uint64_t SectionAddress;
98 if (std::error_code EC = SecI->getAddress(SectionAddress))
101 Result = Address - SectionAddress;
102 return object_error::success;
105 ObjectImage *RuntimeDyldImpl::loadObject(ObjectImage *InputObject) {
106 MutexGuard locked(lock);
108 std::unique_ptr<ObjectImage> Obj(InputObject);
112 // Save information about our target
113 Arch = (Triple::ArchType)Obj->getArch();
114 IsTargetLittleEndian = Obj->getObjectFile()->isLittleEndian();
116 // Compute the memory size required to load all sections to be loaded
117 // and pass this information to the memory manager
118 if (MemMgr->needsToReserveAllocationSpace()) {
119 uint64_t CodeSize = 0, DataSizeRO = 0, DataSizeRW = 0;
120 computeTotalAllocSize(*Obj, CodeSize, DataSizeRO, DataSizeRW);
121 MemMgr->reserveAllocationSpace(CodeSize, DataSizeRO, DataSizeRW);
124 // Symbols found in this object
125 StringMap<SymbolLoc> LocalSymbols;
126 // Used sections from the object file
127 ObjSectionToIDMap LocalSections;
129 // Common symbols requiring allocation, with their sizes and alignments
130 CommonSymbolMap CommonSymbols;
131 // Maximum required total memory to allocate all common symbols
132 uint64_t CommonSize = 0;
135 DEBUG(dbgs() << "Parse symbols:\n");
136 for (symbol_iterator I = Obj->begin_symbols(), E = Obj->end_symbols(); I != E;
138 object::SymbolRef::Type SymType;
140 Check(I->getType(SymType));
141 Check(I->getName(Name));
143 uint32_t Flags = I->getFlags();
145 bool IsCommon = Flags & SymbolRef::SF_Common;
147 // Add the common symbols to a list. We'll allocate them all below.
148 if (!GlobalSymbolTable.count(Name)) {
150 Check(I->getAlignment(Align));
152 Check(I->getSize(Size));
153 CommonSize += Size + Align;
154 CommonSymbols[*I] = CommonSymbolInfo(Size, Align);
157 if (SymType == object::SymbolRef::ST_Function ||
158 SymType == object::SymbolRef::ST_Data ||
159 SymType == object::SymbolRef::ST_Unknown) {
161 StringRef SectionData;
163 section_iterator SI = Obj->end_sections();
164 Check(getOffset(*I, SectOffset));
165 Check(I->getSection(SI));
166 if (SI == Obj->end_sections())
168 Check(SI->getContents(SectionData));
169 Check(SI->isText(IsCode));
171 findOrEmitSection(*Obj, *SI, IsCode, LocalSections);
172 LocalSymbols[Name.data()] = SymbolLoc(SectionID, SectOffset);
173 DEBUG(dbgs() << "\tOffset: " << format("%p", (uintptr_t)SectOffset)
174 << " flags: " << Flags << " SID: " << SectionID);
175 GlobalSymbolTable[Name] = SymbolLoc(SectionID, SectOffset);
178 DEBUG(dbgs() << "\tType: " << SymType << " Name: " << Name << "\n");
181 // Allocate common symbols
183 emitCommonSymbols(*Obj, CommonSymbols, CommonSize, GlobalSymbolTable);
185 // Parse and process relocations
186 DEBUG(dbgs() << "Parse relocations:\n");
187 for (section_iterator SI = Obj->begin_sections(), SE = Obj->end_sections();
189 unsigned SectionID = 0;
191 section_iterator RelocatedSection = SI->getRelocatedSection();
193 relocation_iterator I = SI->relocation_begin();
194 relocation_iterator E = SI->relocation_end();
196 if (I == E && !ProcessAllSections)
200 Check(RelocatedSection->isText(IsCode));
202 findOrEmitSection(*Obj, *RelocatedSection, IsCode, LocalSections);
203 DEBUG(dbgs() << "\tSectionID: " << SectionID << "\n");
206 I = processRelocationRef(SectionID, I, *Obj, LocalSections, LocalSymbols,
210 // If there is an attached checker, notify it about the stubs for this
211 // section so that they can be verified.
213 Checker->registerStubMap(Obj->getImageName(), SectionID, Stubs);
217 // Give the subclasses a chance to tie-up any loose ends.
218 finalizeLoad(*Obj, LocalSections);
220 return Obj.release();
223 // A helper method for computeTotalAllocSize.
224 // Computes the memory size required to allocate sections with the given sizes,
225 // assuming that all sections are allocated with the given alignment
227 computeAllocationSizeForSections(std::vector<uint64_t> &SectionSizes,
228 uint64_t Alignment) {
229 uint64_t TotalSize = 0;
230 for (size_t Idx = 0, Cnt = SectionSizes.size(); Idx < Cnt; Idx++) {
231 uint64_t AlignedSize =
232 (SectionSizes[Idx] + Alignment - 1) / Alignment * Alignment;
233 TotalSize += AlignedSize;
238 // Compute an upper bound of the memory size that is required to load all
240 void RuntimeDyldImpl::computeTotalAllocSize(ObjectImage &Obj,
242 uint64_t &DataSizeRO,
243 uint64_t &DataSizeRW) {
244 // Compute the size of all sections required for execution
245 std::vector<uint64_t> CodeSectionSizes;
246 std::vector<uint64_t> ROSectionSizes;
247 std::vector<uint64_t> RWSectionSizes;
248 uint64_t MaxAlignment = sizeof(void *);
250 // Collect sizes of all sections to be loaded;
251 // also determine the max alignment of all sections
252 for (section_iterator SI = Obj.begin_sections(), SE = Obj.end_sections();
254 const SectionRef &Section = *SI;
257 Check(Section.isRequiredForExecution(IsRequired));
259 // Consider only the sections that are required to be loaded for execution
261 uint64_t DataSize = 0;
262 uint64_t Alignment64 = 0;
264 bool IsReadOnly = false;
266 Check(Section.getSize(DataSize));
267 Check(Section.getAlignment(Alignment64));
268 Check(Section.isText(IsCode));
269 Check(Section.isReadOnlyData(IsReadOnly));
270 Check(Section.getName(Name));
271 unsigned Alignment = (unsigned)Alignment64 & 0xffffffffL;
273 uint64_t StubBufSize = computeSectionStubBufSize(Obj, Section);
274 uint64_t SectionSize = DataSize + StubBufSize;
276 // The .eh_frame section (at least on Linux) needs an extra four bytes
278 // with zeroes added at the end. For MachO objects, this section has a
279 // slightly different name, so this won't have any effect for MachO
281 if (Name == ".eh_frame")
284 if (SectionSize > 0) {
285 // save the total size of the section
287 CodeSectionSizes.push_back(SectionSize);
288 } else if (IsReadOnly) {
289 ROSectionSizes.push_back(SectionSize);
291 RWSectionSizes.push_back(SectionSize);
293 // update the max alignment
294 if (Alignment > MaxAlignment) {
295 MaxAlignment = Alignment;
301 // Compute the size of all common symbols
302 uint64_t CommonSize = 0;
303 for (symbol_iterator I = Obj.begin_symbols(), E = Obj.end_symbols(); I != E;
305 uint32_t Flags = I->getFlags();
306 if (Flags & SymbolRef::SF_Common) {
307 // Add the common symbols to a list. We'll allocate them all below.
309 Check(I->getSize(Size));
313 if (CommonSize != 0) {
314 RWSectionSizes.push_back(CommonSize);
317 // Compute the required allocation space for each different type of sections
318 // (code, read-only data, read-write data) assuming that all sections are
319 // allocated with the max alignment. Note that we cannot compute with the
320 // individual alignments of the sections, because then the required size
321 // depends on the order, in which the sections are allocated.
322 CodeSize = computeAllocationSizeForSections(CodeSectionSizes, MaxAlignment);
323 DataSizeRO = computeAllocationSizeForSections(ROSectionSizes, MaxAlignment);
324 DataSizeRW = computeAllocationSizeForSections(RWSectionSizes, MaxAlignment);
327 // compute stub buffer size for the given section
328 unsigned RuntimeDyldImpl::computeSectionStubBufSize(ObjectImage &Obj,
329 const SectionRef &Section) {
330 unsigned StubSize = getMaxStubSize();
334 // FIXME: this is an inefficient way to handle this. We should computed the
335 // necessary section allocation size in loadObject by walking all the sections
337 unsigned StubBufSize = 0;
338 for (section_iterator SI = Obj.begin_sections(), SE = Obj.end_sections();
340 section_iterator RelSecI = SI->getRelocatedSection();
341 if (!(RelSecI == Section))
344 for (const RelocationRef &Reloc : SI->relocations()) {
346 StubBufSize += StubSize;
350 // Get section data size and alignment
351 uint64_t Alignment64;
353 Check(Section.getSize(DataSize));
354 Check(Section.getAlignment(Alignment64));
356 // Add stubbuf size alignment
357 unsigned Alignment = (unsigned)Alignment64 & 0xffffffffL;
358 unsigned StubAlignment = getStubAlignment();
359 unsigned EndAlignment = (DataSize | Alignment) & -(DataSize | Alignment);
360 if (StubAlignment > EndAlignment)
361 StubBufSize += StubAlignment - EndAlignment;
365 void RuntimeDyldImpl::emitCommonSymbols(ObjectImage &Obj,
366 const CommonSymbolMap &CommonSymbols,
368 SymbolTableMap &SymbolTable) {
369 // Allocate memory for the section
370 unsigned SectionID = Sections.size();
371 uint8_t *Addr = MemMgr->allocateDataSection(TotalSize, sizeof(void *),
372 SectionID, StringRef(), false);
374 report_fatal_error("Unable to allocate memory for common symbols!");
376 Sections.push_back(SectionEntry(StringRef(), Addr, TotalSize, 0));
377 memset(Addr, 0, TotalSize);
379 DEBUG(dbgs() << "emitCommonSection SectionID: " << SectionID << " new addr: "
380 << format("%p", Addr) << " DataSize: " << TotalSize << "\n");
382 // Assign the address of each symbol
383 for (CommonSymbolMap::const_iterator it = CommonSymbols.begin(),
384 itEnd = CommonSymbols.end(); it != itEnd; ++it) {
385 uint64_t Size = it->second.first;
386 uint64_t Align = it->second.second;
388 it->first.getName(Name);
390 // This symbol has an alignment requirement.
391 uint64_t AlignOffset = OffsetToAlignment((uint64_t)Addr, Align);
393 Offset += AlignOffset;
394 DEBUG(dbgs() << "Allocating common symbol " << Name << " address "
395 << format("%p\n", Addr));
397 Obj.updateSymbolAddress(it->first, (uint64_t)Addr);
398 SymbolTable[Name.data()] = SymbolLoc(SectionID, Offset);
404 unsigned RuntimeDyldImpl::emitSection(ObjectImage &Obj,
405 const SectionRef &Section, bool IsCode) {
408 uint64_t Alignment64;
409 Check(Section.getContents(data));
410 Check(Section.getAlignment(Alignment64));
412 unsigned Alignment = (unsigned)Alignment64 & 0xffffffffL;
418 unsigned PaddingSize = 0;
419 unsigned StubBufSize = 0;
421 Check(Section.isRequiredForExecution(IsRequired));
422 Check(Section.isVirtual(IsVirtual));
423 Check(Section.isZeroInit(IsZeroInit));
424 Check(Section.isReadOnlyData(IsReadOnly));
425 Check(Section.getSize(DataSize));
426 Check(Section.getName(Name));
428 StubBufSize = computeSectionStubBufSize(Obj, Section);
430 // The .eh_frame section (at least on Linux) needs an extra four bytes padded
431 // with zeroes added at the end. For MachO objects, this section has a
432 // slightly different name, so this won't have any effect for MachO objects.
433 if (Name == ".eh_frame")
437 unsigned SectionID = Sections.size();
439 const char *pData = nullptr;
441 // Some sections, such as debug info, don't need to be loaded for execution.
442 // Leave those where they are.
444 Allocate = DataSize + PaddingSize + StubBufSize;
445 Addr = IsCode ? MemMgr->allocateCodeSection(Allocate, Alignment, SectionID,
447 : MemMgr->allocateDataSection(Allocate, Alignment, SectionID,
450 report_fatal_error("Unable to allocate section memory!");
452 // Virtual sections have no data in the object image, so leave pData = 0
456 // Zero-initialize or copy the data from the image
457 if (IsZeroInit || IsVirtual)
458 memset(Addr, 0, DataSize);
460 memcpy(Addr, pData, DataSize);
462 // Fill in any extra bytes we allocated for padding
463 if (PaddingSize != 0) {
464 memset(Addr + DataSize, 0, PaddingSize);
465 // Update the DataSize variable so that the stub offset is set correctly.
466 DataSize += PaddingSize;
469 DEBUG(dbgs() << "emitSection SectionID: " << SectionID << " Name: " << Name
470 << " obj addr: " << format("%p", pData)
471 << " new addr: " << format("%p", Addr)
472 << " DataSize: " << DataSize << " StubBufSize: " << StubBufSize
473 << " Allocate: " << Allocate << "\n");
474 Obj.updateSectionAddress(Section, (uint64_t)Addr);
476 // Even if we didn't load the section, we need to record an entry for it
477 // to handle later processing (and by 'handle' I mean don't do anything
478 // with these sections).
481 DEBUG(dbgs() << "emitSection SectionID: " << SectionID << " Name: " << Name
482 << " obj addr: " << format("%p", data.data()) << " new addr: 0"
483 << " DataSize: " << DataSize << " StubBufSize: " << StubBufSize
484 << " Allocate: " << Allocate << "\n");
487 Sections.push_back(SectionEntry(Name, Addr, DataSize, (uintptr_t)pData));
491 unsigned RuntimeDyldImpl::findOrEmitSection(ObjectImage &Obj,
492 const SectionRef &Section,
494 ObjSectionToIDMap &LocalSections) {
496 unsigned SectionID = 0;
497 ObjSectionToIDMap::iterator i = LocalSections.find(Section);
498 if (i != LocalSections.end())
499 SectionID = i->second;
501 SectionID = emitSection(Obj, Section, IsCode);
502 LocalSections[Section] = SectionID;
507 void RuntimeDyldImpl::addRelocationForSection(const RelocationEntry &RE,
508 unsigned SectionID) {
509 Relocations[SectionID].push_back(RE);
512 void RuntimeDyldImpl::addRelocationForSymbol(const RelocationEntry &RE,
513 StringRef SymbolName) {
514 // Relocation by symbol. If the symbol is found in the global symbol table,
515 // create an appropriate section relocation. Otherwise, add it to
516 // ExternalSymbolRelocations.
517 SymbolTableMap::const_iterator Loc = GlobalSymbolTable.find(SymbolName);
518 if (Loc == GlobalSymbolTable.end()) {
519 ExternalSymbolRelocations[SymbolName].push_back(RE);
521 // Copy the RE since we want to modify its addend.
522 RelocationEntry RECopy = RE;
523 RECopy.Addend += Loc->second.second;
524 Relocations[Loc->second.first].push_back(RECopy);
528 uint8_t *RuntimeDyldImpl::createStubFunction(uint8_t *Addr,
529 unsigned AbiVariant) {
530 if (Arch == Triple::aarch64 || Arch == Triple::aarch64_be ||
531 Arch == Triple::arm64 || Arch == Triple::arm64_be) {
532 // This stub has to be able to access the full address space,
533 // since symbol lookup won't necessarily find a handy, in-range,
534 // PLT stub for functions which could be anywhere.
535 uint32_t *StubAddr = (uint32_t *)Addr;
537 // Stub can use ip0 (== x16) to calculate address
538 *StubAddr = 0xd2e00010; // movz ip0, #:abs_g3:<addr>
540 *StubAddr = 0xf2c00010; // movk ip0, #:abs_g2_nc:<addr>
542 *StubAddr = 0xf2a00010; // movk ip0, #:abs_g1_nc:<addr>
544 *StubAddr = 0xf2800010; // movk ip0, #:abs_g0_nc:<addr>
546 *StubAddr = 0xd61f0200; // br ip0
549 } else if (Arch == Triple::arm || Arch == Triple::armeb) {
550 // TODO: There is only ARM far stub now. We should add the Thumb stub,
551 // and stubs for branches Thumb - ARM and ARM - Thumb.
552 uint32_t *StubAddr = (uint32_t *)Addr;
553 *StubAddr = 0xe51ff004; // ldr pc,<label>
554 return (uint8_t *)++StubAddr;
555 } else if (Arch == Triple::mipsel || Arch == Triple::mips) {
556 uint32_t *StubAddr = (uint32_t *)Addr;
557 // 0: 3c190000 lui t9,%hi(addr).
558 // 4: 27390000 addiu t9,t9,%lo(addr).
559 // 8: 03200008 jr t9.
561 const unsigned LuiT9Instr = 0x3c190000, AdduiT9Instr = 0x27390000;
562 const unsigned JrT9Instr = 0x03200008, NopInstr = 0x0;
564 *StubAddr = LuiT9Instr;
566 *StubAddr = AdduiT9Instr;
568 *StubAddr = JrT9Instr;
570 *StubAddr = NopInstr;
572 } else if (Arch == Triple::ppc64 || Arch == Triple::ppc64le) {
573 // Depending on which version of the ELF ABI is in use, we need to
574 // generate one of two variants of the stub. They both start with
575 // the same sequence to load the target address into r12.
576 writeInt32BE(Addr, 0x3D800000); // lis r12, highest(addr)
577 writeInt32BE(Addr+4, 0x618C0000); // ori r12, higher(addr)
578 writeInt32BE(Addr+8, 0x798C07C6); // sldi r12, r12, 32
579 writeInt32BE(Addr+12, 0x658C0000); // oris r12, r12, h(addr)
580 writeInt32BE(Addr+16, 0x618C0000); // ori r12, r12, l(addr)
581 if (AbiVariant == 2) {
582 // PowerPC64 stub ELFv2 ABI: The address points to the function itself.
583 // The address is already in r12 as required by the ABI. Branch to it.
584 writeInt32BE(Addr+20, 0xF8410018); // std r2, 24(r1)
585 writeInt32BE(Addr+24, 0x7D8903A6); // mtctr r12
586 writeInt32BE(Addr+28, 0x4E800420); // bctr
588 // PowerPC64 stub ELFv1 ABI: The address points to a function descriptor.
589 // Load the function address on r11 and sets it to control register. Also
590 // loads the function TOC in r2 and environment pointer to r11.
591 writeInt32BE(Addr+20, 0xF8410028); // std r2, 40(r1)
592 writeInt32BE(Addr+24, 0xE96C0000); // ld r11, 0(r12)
593 writeInt32BE(Addr+28, 0xE84C0008); // ld r2, 0(r12)
594 writeInt32BE(Addr+32, 0x7D6903A6); // mtctr r11
595 writeInt32BE(Addr+36, 0xE96C0010); // ld r11, 16(r2)
596 writeInt32BE(Addr+40, 0x4E800420); // bctr
599 } else if (Arch == Triple::systemz) {
600 writeInt16BE(Addr, 0xC418); // lgrl %r1,.+8
601 writeInt16BE(Addr+2, 0x0000);
602 writeInt16BE(Addr+4, 0x0004);
603 writeInt16BE(Addr+6, 0x07F1); // brc 15,%r1
604 // 8-byte address stored at Addr + 8
606 } else if (Arch == Triple::x86_64) {
608 *(Addr+1) = 0x25; // rip
609 // 32-bit PC-relative address of the GOT entry will be stored at Addr+2
610 } else if (Arch == Triple::x86) {
611 *Addr = 0xE9; // 32-bit pc-relative jump.
616 // Assign an address to a symbol name and resolve all the relocations
617 // associated with it.
618 void RuntimeDyldImpl::reassignSectionAddress(unsigned SectionID,
620 // The address to use for relocation resolution is not
621 // the address of the local section buffer. We must be doing
622 // a remote execution environment of some sort. Relocations can't
623 // be applied until all the sections have been moved. The client must
624 // trigger this with a call to MCJIT::finalize() or
625 // RuntimeDyld::resolveRelocations().
627 // Addr is a uint64_t because we can't assume the pointer width
628 // of the target is the same as that of the host. Just use a generic
629 // "big enough" type.
630 Sections[SectionID].LoadAddress = Addr;
633 void RuntimeDyldImpl::resolveRelocationList(const RelocationList &Relocs,
635 for (unsigned i = 0, e = Relocs.size(); i != e; ++i) {
636 const RelocationEntry &RE = Relocs[i];
637 // Ignore relocations for sections that were not loaded
638 if (Sections[RE.SectionID].Address == nullptr)
640 resolveRelocation(RE, Value);
644 void RuntimeDyldImpl::resolveExternalSymbols() {
645 while (!ExternalSymbolRelocations.empty()) {
646 StringMap<RelocationList>::iterator i = ExternalSymbolRelocations.begin();
648 StringRef Name = i->first();
649 if (Name.size() == 0) {
650 // This is an absolute symbol, use an address of zero.
651 DEBUG(dbgs() << "Resolving absolute relocations."
653 RelocationList &Relocs = i->second;
654 resolveRelocationList(Relocs, 0);
657 SymbolTableMap::const_iterator Loc = GlobalSymbolTable.find(Name);
658 if (Loc == GlobalSymbolTable.end()) {
659 // This is an external symbol, try to get its address from
661 Addr = MemMgr->getSymbolAddress(Name.data());
662 // The call to getSymbolAddress may have caused additional modules to
663 // be loaded, which may have added new entries to the
664 // ExternalSymbolRelocations map. Consquently, we need to update our
665 // iterator. This is also why retrieval of the relocation list
666 // associated with this symbol is deferred until below this point.
667 // New entries may have been added to the relocation list.
668 i = ExternalSymbolRelocations.find(Name);
670 // We found the symbol in our global table. It was probably in a
671 // Module that we loaded previously.
672 SymbolLoc SymLoc = Loc->second;
673 Addr = getSectionLoadAddress(SymLoc.first) + SymLoc.second;
676 // FIXME: Implement error handling that doesn't kill the host program!
678 report_fatal_error("Program used external function '" + Name +
679 "' which could not be resolved!");
681 updateGOTEntries(Name, Addr);
682 DEBUG(dbgs() << "Resolving relocations Name: " << Name << "\t"
683 << format("0x%lx", Addr) << "\n");
684 // This list may have been updated when we called getSymbolAddress, so
685 // don't change this code to get the list earlier.
686 RelocationList &Relocs = i->second;
687 resolveRelocationList(Relocs, Addr);
690 ExternalSymbolRelocations.erase(i);
694 //===----------------------------------------------------------------------===//
695 // RuntimeDyld class implementation
696 RuntimeDyld::RuntimeDyld(RTDyldMemoryManager *mm) {
697 // FIXME: There's a potential issue lurking here if a single instance of
698 // RuntimeDyld is used to load multiple objects. The current implementation
699 // associates a single memory manager with a RuntimeDyld instance. Even
700 // though the public class spawns a new 'impl' instance for each load,
701 // they share a single memory manager. This can become a problem when page
702 // permissions are applied.
705 ProcessAllSections = false;
709 RuntimeDyld::~RuntimeDyld() { delete Dyld; }
711 static std::unique_ptr<RuntimeDyldELF>
712 createRuntimeDyldELF(RTDyldMemoryManager *MM, bool ProcessAllSections,
713 RuntimeDyldCheckerImpl *Checker) {
714 std::unique_ptr<RuntimeDyldELF> Dyld(new RuntimeDyldELF(MM));
715 Dyld->setProcessAllSections(ProcessAllSections);
716 Dyld->setRuntimeDyldChecker(Checker);
720 static std::unique_ptr<RuntimeDyldMachO>
721 createRuntimeDyldMachO(Triple::ArchType Arch, RTDyldMemoryManager *MM,
722 bool ProcessAllSections, RuntimeDyldCheckerImpl *Checker) {
723 std::unique_ptr<RuntimeDyldMachO> Dyld(RuntimeDyldMachO::create(Arch, MM));
724 Dyld->setProcessAllSections(ProcessAllSections);
725 Dyld->setRuntimeDyldChecker(Checker);
729 ObjectImage *RuntimeDyld::loadObject(std::unique_ptr<ObjectFile> InputObject) {
730 std::unique_ptr<ObjectImage> InputImage;
732 ObjectFile &Obj = *InputObject;
734 if (InputObject->isELF()) {
735 InputImage.reset(RuntimeDyldELF::createObjectImageFromFile(std::move(InputObject)));
737 Dyld = createRuntimeDyldELF(MM, ProcessAllSections, Checker).release();
738 } else if (InputObject->isMachO()) {
739 InputImage.reset(RuntimeDyldMachO::createObjectImageFromFile(std::move(InputObject)));
741 Dyld = createRuntimeDyldMachO(
742 static_cast<Triple::ArchType>(InputImage->getArch()),
743 MM, ProcessAllSections, Checker).release();
745 report_fatal_error("Incompatible object format!");
747 if (!Dyld->isCompatibleFile(&Obj))
748 report_fatal_error("Incompatible object format!");
750 Dyld->loadObject(InputImage.get());
751 return InputImage.release();
754 ObjectImage *RuntimeDyld::loadObject(ObjectBuffer *InputBuffer) {
755 std::unique_ptr<ObjectImage> InputImage;
756 sys::fs::file_magic Type = sys::fs::identify_magic(InputBuffer->getBuffer());
759 case sys::fs::file_magic::elf_relocatable:
760 case sys::fs::file_magic::elf_executable:
761 case sys::fs::file_magic::elf_shared_object:
762 case sys::fs::file_magic::elf_core:
763 InputImage.reset(RuntimeDyldELF::createObjectImage(InputBuffer));
765 Dyld = createRuntimeDyldELF(MM, ProcessAllSections, Checker).release();
767 case sys::fs::file_magic::macho_object:
768 case sys::fs::file_magic::macho_executable:
769 case sys::fs::file_magic::macho_fixed_virtual_memory_shared_lib:
770 case sys::fs::file_magic::macho_core:
771 case sys::fs::file_magic::macho_preload_executable:
772 case sys::fs::file_magic::macho_dynamically_linked_shared_lib:
773 case sys::fs::file_magic::macho_dynamic_linker:
774 case sys::fs::file_magic::macho_bundle:
775 case sys::fs::file_magic::macho_dynamically_linked_shared_lib_stub:
776 case sys::fs::file_magic::macho_dsym_companion:
777 InputImage.reset(RuntimeDyldMachO::createObjectImage(InputBuffer));
779 Dyld = createRuntimeDyldMachO(
780 static_cast<Triple::ArchType>(InputImage->getArch()),
781 MM, ProcessAllSections, Checker).release();
783 case sys::fs::file_magic::unknown:
784 case sys::fs::file_magic::bitcode:
785 case sys::fs::file_magic::archive:
786 case sys::fs::file_magic::coff_object:
787 case sys::fs::file_magic::coff_import_library:
788 case sys::fs::file_magic::pecoff_executable:
789 case sys::fs::file_magic::macho_universal_binary:
790 case sys::fs::file_magic::windows_resource:
791 report_fatal_error("Incompatible object format!");
794 if (!Dyld->isCompatibleFormat(InputBuffer))
795 report_fatal_error("Incompatible object format!");
797 Dyld->loadObject(InputImage.get());
798 return InputImage.release();
801 void *RuntimeDyld::getSymbolAddress(StringRef Name) {
804 return Dyld->getSymbolAddress(Name);
807 uint64_t RuntimeDyld::getSymbolLoadAddress(StringRef Name) {
810 return Dyld->getSymbolLoadAddress(Name);
813 void RuntimeDyld::resolveRelocations() { Dyld->resolveRelocations(); }
815 void RuntimeDyld::reassignSectionAddress(unsigned SectionID, uint64_t Addr) {
816 Dyld->reassignSectionAddress(SectionID, Addr);
819 void RuntimeDyld::mapSectionAddress(const void *LocalAddress,
820 uint64_t TargetAddress) {
821 Dyld->mapSectionAddress(LocalAddress, TargetAddress);
824 bool RuntimeDyld::hasError() { return Dyld->hasError(); }
826 StringRef RuntimeDyld::getErrorString() { return Dyld->getErrorString(); }
828 void RuntimeDyld::registerEHFrames() {
830 Dyld->registerEHFrames();
833 void RuntimeDyld::deregisterEHFrames() {
835 Dyld->deregisterEHFrames();
838 } // end namespace llvm