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 #define DEBUG_TYPE "dyld"
15 #include "ObjectImageCommon.h"
16 #include "RuntimeDyldImpl.h"
17 #include "RuntimeDyldELF.h"
18 #include "RuntimeDyldMachO.h"
19 #include "llvm/Support/Path.h"
22 using namespace llvm::object;
24 // Empty out-of-line virtual destructor as the key function.
25 RTDyldMemoryManager::~RTDyldMemoryManager() {}
26 RuntimeDyldImpl::~RuntimeDyldImpl() {}
31 // Helper for extensive error checking in debug builds.
32 error_code Check(error_code Err) {
34 report_fatal_error(Err.message());
38 } // end anonymous namespace
40 // Resolve the relocations for all symbols we currently know about.
41 void RuntimeDyldImpl::resolveRelocations() {
42 // First, resolve relocations associated with external symbols.
43 resolveExternalSymbols();
45 // Just iterate over the sections we have and resolve all the relocations
46 // in them. Gross overkill, but it gets the job done.
47 for (int i = 0, e = Sections.size(); i != e; ++i) {
48 reassignSectionAddress(i, Sections[i].LoadAddress);
52 void RuntimeDyldImpl::mapSectionAddress(const void *LocalAddress,
53 uint64_t TargetAddress) {
54 for (unsigned i = 0, e = Sections.size(); i != e; ++i) {
55 if (Sections[i].Address == LocalAddress) {
56 reassignSectionAddress(i, TargetAddress);
60 llvm_unreachable("Attempting to remap address of unknown section!");
63 // Subclasses can implement this method to create specialized image instances.
64 // The caller owns the pointer that is returned.
65 ObjectImage *RuntimeDyldImpl::createObjectImage(ObjectBuffer *InputBuffer) {
66 return new ObjectImageCommon(InputBuffer);
69 ObjectImage *RuntimeDyldImpl::loadObject(ObjectBuffer *InputBuffer) {
70 OwningPtr<ObjectImage> obj(createObjectImage(InputBuffer));
72 report_fatal_error("Unable to create object image from memory buffer!");
74 Arch = (Triple::ArchType)obj->getArch();
76 // Symbols found in this object
77 StringMap<SymbolLoc> LocalSymbols;
78 // Used sections from the object file
79 ObjSectionToIDMap LocalSections;
81 // Common symbols requiring allocation, and the total size required to
82 // allocate all common symbols.
83 CommonSymbolMap CommonSymbols;
84 uint64_t CommonSize = 0;
88 DEBUG(dbgs() << "Parse symbols:\n");
89 for (symbol_iterator i = obj->begin_symbols(), e = obj->end_symbols();
90 i != e; i.increment(err)) {
92 object::SymbolRef::Type SymType;
94 Check(i->getType(SymType));
95 Check(i->getName(Name));
98 Check(i->getFlags(flags));
100 bool isCommon = flags & SymbolRef::SF_Common;
102 // Add the common symbols to a list. We'll allocate them all below.
104 Check(i->getSize(Size));
106 CommonSymbols[*i] = Size;
108 if (SymType == object::SymbolRef::ST_Function ||
109 SymType == object::SymbolRef::ST_Data ||
110 SymType == object::SymbolRef::ST_Unknown) {
112 StringRef SectionData;
113 section_iterator si = obj->end_sections();
114 Check(i->getFileOffset(FileOffset));
115 Check(i->getSection(si));
116 if (si == obj->end_sections()) continue;
117 Check(si->getContents(SectionData));
118 const uint8_t* SymPtr = (const uint8_t*)InputBuffer->getBufferStart() +
119 (uintptr_t)FileOffset;
120 uintptr_t SectOffset = (uintptr_t)(SymPtr -
121 (const uint8_t*)SectionData.begin());
123 findOrEmitSection(*obj,
125 SymType == object::SymbolRef::ST_Function,
127 LocalSymbols[Name.data()] = SymbolLoc(SectionID, SectOffset);
128 DEBUG(dbgs() << "\tFileOffset: " << format("%p", (uintptr_t)FileOffset)
129 << " flags: " << flags
130 << " SID: " << SectionID
131 << " Offset: " << format("%p", SectOffset));
132 bool isGlobal = flags & SymbolRef::SF_Global;
134 GlobalSymbolTable[Name] = SymbolLoc(SectionID, SectOffset);
137 DEBUG(dbgs() << "\tType: " << SymType << " Name: " << Name << "\n");
140 // Allocate common symbols
142 emitCommonSymbols(*obj, CommonSymbols, CommonSize, LocalSymbols);
144 // Parse and process relocations
145 DEBUG(dbgs() << "Parse relocations:\n");
146 for (section_iterator si = obj->begin_sections(),
147 se = obj->end_sections(); si != se; si.increment(err)) {
149 bool isFirstRelocation = true;
150 unsigned SectionID = 0;
153 for (relocation_iterator i = si->begin_relocations(),
154 e = si->end_relocations(); i != e; i.increment(err)) {
157 // If it's the first relocation in this section, find its SectionID
158 if (isFirstRelocation) {
159 SectionID = findOrEmitSection(*obj, *si, true, LocalSections);
160 DEBUG(dbgs() << "\tSectionID: " << SectionID << "\n");
161 isFirstRelocation = false;
164 ObjRelocationInfo RI;
165 RI.SectionID = SectionID;
166 Check(i->getAdditionalInfo(RI.AdditionalInfo));
167 Check(i->getOffset(RI.Offset));
168 Check(i->getSymbol(RI.Symbol));
169 Check(i->getType(RI.Type));
171 DEBUG(dbgs() << "\t\tAddend: " << RI.AdditionalInfo
172 << " Offset: " << format("%p", (uintptr_t)RI.Offset)
173 << " Type: " << (uint32_t)(RI.Type & 0xffffffffL)
175 processRelocationRef(RI, *obj, LocalSections, LocalSymbols, Stubs);
182 void RuntimeDyldImpl::emitCommonSymbols(ObjectImage &Obj,
183 const CommonSymbolMap &CommonSymbols,
185 SymbolTableMap &SymbolTable) {
186 // Allocate memory for the section
187 unsigned SectionID = Sections.size();
188 uint8_t *Addr = MemMgr->allocateDataSection(TotalSize, sizeof(void*),
191 report_fatal_error("Unable to allocate memory for common symbols!");
193 Sections.push_back(SectionEntry(StringRef(), Addr, TotalSize, TotalSize, 0));
194 memset(Addr, 0, TotalSize);
196 DEBUG(dbgs() << "emitCommonSection SectionID: " << SectionID
197 << " new addr: " << format("%p", Addr)
198 << " DataSize: " << TotalSize
201 // Assign the address of each symbol
202 for (CommonSymbolMap::const_iterator it = CommonSymbols.begin(),
203 itEnd = CommonSymbols.end(); it != itEnd; it++) {
205 it->first.getName(Name);
206 Obj.updateSymbolAddress(it->first, (uint64_t)Addr);
207 SymbolTable[Name.data()] = SymbolLoc(SectionID, Offset);
208 uint64_t Size = it->second;
214 unsigned RuntimeDyldImpl::emitSection(ObjectImage &Obj,
215 const SectionRef &Section,
218 unsigned StubBufSize = 0,
219 StubSize = getMaxStubSize();
222 for (relocation_iterator i = Section.begin_relocations(),
223 e = Section.end_relocations(); i != e; i.increment(err), Check(err))
224 StubBufSize += StubSize;
227 uint64_t Alignment64;
228 Check(Section.getContents(data));
229 Check(Section.getAlignment(Alignment64));
231 unsigned Alignment = (unsigned)Alignment64 & 0xffffffffL;
237 Check(Section.isRequiredForExecution(IsRequired));
238 Check(Section.isVirtual(IsVirtual));
239 Check(Section.isZeroInit(IsZeroInit));
240 Check(Section.getSize(DataSize));
241 Check(Section.getName(Name));
244 unsigned SectionID = Sections.size();
246 const char *pData = 0;
248 // Some sections, such as debug info, don't need to be loaded for execution.
249 // Leave those where they are.
251 Allocate = DataSize + StubBufSize;
253 ? MemMgr->allocateCodeSection(Allocate, Alignment, SectionID)
254 : MemMgr->allocateDataSection(Allocate, Alignment, SectionID);
256 report_fatal_error("Unable to allocate section memory!");
258 // Virtual sections have no data in the object image, so leave pData = 0
262 // Zero-initialize or copy the data from the image
263 if (IsZeroInit || IsVirtual)
264 memset(Addr, 0, DataSize);
266 memcpy(Addr, pData, DataSize);
268 DEBUG(dbgs() << "emitSection SectionID: " << SectionID
270 << " obj addr: " << format("%p", pData)
271 << " new addr: " << format("%p", Addr)
272 << " DataSize: " << DataSize
273 << " StubBufSize: " << StubBufSize
274 << " Allocate: " << Allocate
276 Obj.updateSectionAddress(Section, (uint64_t)Addr);
279 // Even if we didn't load the section, we need to record an entry for it
280 // to handle later processing (and by 'handle' I mean don't do anything
281 // with these sections).
284 DEBUG(dbgs() << "emitSection SectionID: " << SectionID
286 << " obj addr: " << format("%p", data.data())
288 << " DataSize: " << DataSize
289 << " StubBufSize: " << StubBufSize
290 << " Allocate: " << Allocate
294 Sections.push_back(SectionEntry(Name, Addr, Allocate, DataSize,
299 unsigned RuntimeDyldImpl::findOrEmitSection(ObjectImage &Obj,
300 const SectionRef &Section,
302 ObjSectionToIDMap &LocalSections) {
304 unsigned SectionID = 0;
305 ObjSectionToIDMap::iterator i = LocalSections.find(Section);
306 if (i != LocalSections.end())
307 SectionID = i->second;
309 SectionID = emitSection(Obj, Section, IsCode);
310 LocalSections[Section] = SectionID;
315 void RuntimeDyldImpl::addRelocationForSection(const RelocationEntry &RE,
316 unsigned SectionID) {
317 Relocations[SectionID].push_back(RE);
320 void RuntimeDyldImpl::addRelocationForSymbol(const RelocationEntry &RE,
321 StringRef SymbolName) {
322 // Relocation by symbol. If the symbol is found in the global symbol table,
323 // create an appropriate section relocation. Otherwise, add it to
324 // ExternalSymbolRelocations.
325 SymbolTableMap::const_iterator Loc =
326 GlobalSymbolTable.find(SymbolName);
327 if (Loc == GlobalSymbolTable.end()) {
328 ExternalSymbolRelocations[SymbolName].push_back(RE);
330 // Copy the RE since we want to modify its addend.
331 RelocationEntry RECopy = RE;
332 RECopy.Addend += Loc->second.second;
333 Relocations[Loc->second.first].push_back(RECopy);
337 uint8_t *RuntimeDyldImpl::createStubFunction(uint8_t *Addr) {
338 if (Arch == Triple::arm) {
339 // TODO: There is only ARM far stub now. We should add the Thumb stub,
340 // and stubs for branches Thumb - ARM and ARM - Thumb.
341 uint32_t *StubAddr = (uint32_t*)Addr;
342 *StubAddr = 0xe51ff004; // ldr pc,<label>
343 return (uint8_t*)++StubAddr;
344 } else if (Arch == Triple::mipsel) {
345 uint32_t *StubAddr = (uint32_t*)Addr;
346 // 0: 3c190000 lui t9,%hi(addr).
347 // 4: 27390000 addiu t9,t9,%lo(addr).
348 // 8: 03200008 jr t9.
350 const unsigned LuiT9Instr = 0x3c190000, AdduiT9Instr = 0x27390000;
351 const unsigned JrT9Instr = 0x03200008, NopInstr = 0x0;
353 *StubAddr = LuiT9Instr;
355 *StubAddr = AdduiT9Instr;
357 *StubAddr = JrT9Instr;
359 *StubAddr = NopInstr;
361 } else if (Arch == Triple::ppc64) {
362 // PowerPC64 stub: the address points to a function descriptor
363 // instead of the function itself. Load the function address
364 // on r11 and sets it to control register. Also loads the function
365 // TOC in r2 and environment pointer to r11.
366 writeInt32BE(Addr, 0x3D800000); // lis r12, highest(addr)
367 writeInt32BE(Addr+4, 0x618C0000); // ori r12, higher(addr)
368 writeInt32BE(Addr+8, 0x798C07C6); // sldi r12, r12, 32
369 writeInt32BE(Addr+12, 0x658C0000); // oris r12, r12, h(addr)
370 writeInt32BE(Addr+16, 0x618C0000); // ori r12, r12, l(addr)
371 writeInt32BE(Addr+20, 0xF8410028); // std r2, 40(r1)
372 writeInt32BE(Addr+24, 0xE96C0000); // ld r11, 0(r12)
373 writeInt32BE(Addr+28, 0xE84C0008); // ld r2, 0(r12)
374 writeInt32BE(Addr+32, 0x7D6903A6); // mtctr r11
375 writeInt32BE(Addr+36, 0xE96C0010); // ld r11, 16(r2)
376 writeInt32BE(Addr+40, 0x4E800420); // bctr
383 // Assign an address to a symbol name and resolve all the relocations
384 // associated with it.
385 void RuntimeDyldImpl::reassignSectionAddress(unsigned SectionID,
387 // The address to use for relocation resolution is not
388 // the address of the local section buffer. We must be doing
389 // a remote execution environment of some sort. Re-apply any
390 // relocations referencing this section with the given address.
392 // Addr is a uint64_t because we can't assume the pointer width
393 // of the target is the same as that of the host. Just use a generic
394 // "big enough" type.
395 Sections[SectionID].LoadAddress = Addr;
396 DEBUG(dbgs() << "Resolving relocations Section #" << SectionID
397 << "\t" << format("%p", (uint8_t *)Addr)
399 resolveRelocationList(Relocations[SectionID], Addr);
402 void RuntimeDyldImpl::resolveRelocationEntry(const RelocationEntry &RE,
404 // Ignore relocations for sections that were not loaded
405 if (Sections[RE.SectionID].Address != 0) {
406 uint8_t *Target = Sections[RE.SectionID].Address + RE.Offset;
407 DEBUG(dbgs() << "\tSectionID: " << RE.SectionID
408 << " + " << RE.Offset << " (" << format("%p", Target) << ")"
409 << " RelType: " << RE.RelType
410 << " Addend: " << RE.Addend
413 resolveRelocation(Target, Sections[RE.SectionID].LoadAddress + RE.Offset,
414 Value, RE.RelType, RE.Addend);
418 void RuntimeDyldImpl::resolveRelocationList(const RelocationList &Relocs,
420 for (unsigned i = 0, e = Relocs.size(); i != e; ++i) {
421 resolveRelocationEntry(Relocs[i], Value);
425 void RuntimeDyldImpl::resolveExternalSymbols() {
426 StringMap<RelocationList>::iterator i = ExternalSymbolRelocations.begin(),
427 e = ExternalSymbolRelocations.end();
428 for (; i != e; i++) {
429 StringRef Name = i->first();
430 RelocationList &Relocs = i->second;
431 SymbolTableMap::const_iterator Loc = GlobalSymbolTable.find(Name);
432 if (Loc == GlobalSymbolTable.end()) {
433 // This is an external symbol, try to get it address from
435 uint8_t *Addr = (uint8_t*) MemMgr->getPointerToNamedFunction(Name.data(),
437 DEBUG(dbgs() << "Resolving relocations Name: " << Name
438 << "\t" << format("%p", Addr)
440 resolveRelocationList(Relocs, (uintptr_t)Addr);
442 report_fatal_error("Expected external symbol");
448 //===----------------------------------------------------------------------===//
449 // RuntimeDyld class implementation
450 RuntimeDyld::RuntimeDyld(RTDyldMemoryManager *mm) {
455 RuntimeDyld::~RuntimeDyld() {
459 ObjectImage *RuntimeDyld::loadObject(ObjectBuffer *InputBuffer) {
461 sys::LLVMFileType type = sys::IdentifyFileType(
462 InputBuffer->getBufferStart(),
463 static_cast<unsigned>(InputBuffer->getBufferSize()));
465 case sys::ELF_Relocatable_FileType:
466 case sys::ELF_Executable_FileType:
467 case sys::ELF_SharedObject_FileType:
468 case sys::ELF_Core_FileType:
469 Dyld = new RuntimeDyldELF(MM);
471 case sys::Mach_O_Object_FileType:
472 case sys::Mach_O_Executable_FileType:
473 case sys::Mach_O_FixedVirtualMemorySharedLib_FileType:
474 case sys::Mach_O_Core_FileType:
475 case sys::Mach_O_PreloadExecutable_FileType:
476 case sys::Mach_O_DynamicallyLinkedSharedLib_FileType:
477 case sys::Mach_O_DynamicLinker_FileType:
478 case sys::Mach_O_Bundle_FileType:
479 case sys::Mach_O_DynamicallyLinkedSharedLibStub_FileType:
480 case sys::Mach_O_DSYMCompanion_FileType:
481 Dyld = new RuntimeDyldMachO(MM);
483 case sys::Unknown_FileType:
484 case sys::Bitcode_FileType:
485 case sys::Archive_FileType:
486 case sys::COFF_FileType:
487 report_fatal_error("Incompatible object format!");
490 if (!Dyld->isCompatibleFormat(InputBuffer))
491 report_fatal_error("Incompatible object format!");
494 return Dyld->loadObject(InputBuffer);
497 void *RuntimeDyld::getSymbolAddress(StringRef Name) {
498 return Dyld->getSymbolAddress(Name);
501 uint64_t RuntimeDyld::getSymbolLoadAddress(StringRef Name) {
502 return Dyld->getSymbolLoadAddress(Name);
505 void RuntimeDyld::resolveRelocations() {
506 Dyld->resolveRelocations();
509 void RuntimeDyld::reassignSectionAddress(unsigned SectionID,
511 Dyld->reassignSectionAddress(SectionID, Addr);
514 void RuntimeDyld::mapSectionAddress(const void *LocalAddress,
515 uint64_t TargetAddress) {
516 Dyld->mapSectionAddress(LocalAddress, TargetAddress);
519 StringRef RuntimeDyld::getErrorString() {
520 return Dyld->getErrorString();
523 } // end namespace llvm