Line data Source code
1 : //===-- RuntimeDyld.cpp - Run-time dynamic linker for MC-JIT ----*- C++ -*-===//
2 : //
3 : // The LLVM Compiler Infrastructure
4 : //
5 : // This file is distributed under the University of Illinois Open Source
6 : // License. See LICENSE.TXT for details.
7 : //
8 : //===----------------------------------------------------------------------===//
9 : //
10 : // Implementation of the MC-JIT runtime dynamic linker.
11 : //
12 : //===----------------------------------------------------------------------===//
13 :
14 : #include "llvm/ExecutionEngine/RuntimeDyld.h"
15 : #include "RuntimeDyldCOFF.h"
16 : #include "RuntimeDyldCheckerImpl.h"
17 : #include "RuntimeDyldELF.h"
18 : #include "RuntimeDyldImpl.h"
19 : #include "RuntimeDyldMachO.h"
20 : #include "llvm/Object/COFF.h"
21 : #include "llvm/Object/ELFObjectFile.h"
22 : #include "llvm/Support/MSVCErrorWorkarounds.h"
23 : #include "llvm/Support/ManagedStatic.h"
24 : #include "llvm/Support/MathExtras.h"
25 : #include "llvm/Support/MutexGuard.h"
26 :
27 : #include <future>
28 :
29 : using namespace llvm;
30 : using namespace llvm::object;
31 :
32 : #define DEBUG_TYPE "dyld"
33 :
34 : namespace {
35 :
36 : enum RuntimeDyldErrorCode {
37 : GenericRTDyldError = 1
38 : };
39 :
40 : // FIXME: This class is only here to support the transition to llvm::Error. It
41 : // will be removed once this transition is complete. Clients should prefer to
42 : // deal with the Error value directly, rather than converting to error_code.
43 0 : class RuntimeDyldErrorCategory : public std::error_category {
44 : public:
45 0 : const char *name() const noexcept override { return "runtimedyld"; }
46 :
47 0 : std::string message(int Condition) const override {
48 0 : switch (static_cast<RuntimeDyldErrorCode>(Condition)) {
49 0 : case GenericRTDyldError: return "Generic RuntimeDyld error";
50 : }
51 0 : llvm_unreachable("Unrecognized RuntimeDyldErrorCode");
52 : }
53 : };
54 :
55 : static ManagedStatic<RuntimeDyldErrorCategory> RTDyldErrorCategory;
56 :
57 : }
58 :
59 : char RuntimeDyldError::ID = 0;
60 :
61 0 : void RuntimeDyldError::log(raw_ostream &OS) const {
62 0 : OS << ErrMsg << "\n";
63 0 : }
64 :
65 0 : std::error_code RuntimeDyldError::convertToErrorCode() const {
66 0 : return std::error_code(GenericRTDyldError, *RTDyldErrorCategory);
67 : }
68 :
69 : // Empty out-of-line virtual destructor as the key function.
70 684 : RuntimeDyldImpl::~RuntimeDyldImpl() {}
71 :
72 : // Pin LoadedObjectInfo's vtables to this file.
73 0 : void RuntimeDyld::LoadedObjectInfo::anchor() {}
74 :
75 : namespace llvm {
76 :
77 0 : void RuntimeDyldImpl::registerEHFrames() {}
78 :
79 46 : void RuntimeDyldImpl::deregisterEHFrames() {
80 46 : MemMgr.deregisterEHFrames();
81 46 : }
82 :
83 : #ifndef NDEBUG
84 : static void dumpSectionMemory(const SectionEntry &S, StringRef State) {
85 : dbgs() << "----- Contents of section " << S.getName() << " " << State
86 : << " -----";
87 :
88 : if (S.getAddress() == nullptr) {
89 : dbgs() << "\n <section not emitted>\n";
90 : return;
91 : }
92 :
93 : const unsigned ColsPerRow = 16;
94 :
95 : uint8_t *DataAddr = S.getAddress();
96 : uint64_t LoadAddr = S.getLoadAddress();
97 :
98 : unsigned StartPadding = LoadAddr & (ColsPerRow - 1);
99 : unsigned BytesRemaining = S.getSize();
100 :
101 : if (StartPadding) {
102 : dbgs() << "\n" << format("0x%016" PRIx64,
103 : LoadAddr & ~(uint64_t)(ColsPerRow - 1)) << ":";
104 : while (StartPadding--)
105 : dbgs() << " ";
106 : }
107 :
108 : while (BytesRemaining > 0) {
109 : if ((LoadAddr & (ColsPerRow - 1)) == 0)
110 : dbgs() << "\n" << format("0x%016" PRIx64, LoadAddr) << ":";
111 :
112 : dbgs() << " " << format("%02x", *DataAddr);
113 :
114 : ++DataAddr;
115 : ++LoadAddr;
116 : --BytesRemaining;
117 : }
118 :
119 : dbgs() << "\n";
120 : }
121 : #endif
122 :
123 : // Resolve the relocations for all symbols we currently know about.
124 446 : void RuntimeDyldImpl::resolveRelocations() {
125 : MutexGuard locked(lock);
126 :
127 : // Print out the sections prior to relocation.
128 : LLVM_DEBUG(for (int i = 0, e = Sections.size(); i != e; ++i)
129 : dumpSectionMemory(Sections[i], "before relocations"););
130 :
131 : // First, resolve relocations associated with external symbols.
132 892 : if (auto Err = resolveExternalSymbols()) {
133 0 : HasError = true;
134 0 : ErrorStr = toString(std::move(Err));
135 : }
136 :
137 446 : resolveLocalRelocations();
138 :
139 : // Print out sections after relocation.
140 : LLVM_DEBUG(for (int i = 0, e = Sections.size(); i != e; ++i)
141 : dumpSectionMemory(Sections[i], "after relocations"););
142 446 : }
143 :
144 477 : void RuntimeDyldImpl::resolveLocalRelocations() {
145 : // Iterate over all outstanding relocations
146 973 : for (auto it = Relocations.begin(), e = Relocations.end(); it != e; ++it) {
147 : // The Section here (Sections[i]) refers to the section in which the
148 : // symbol for the relocation is located. The SectionID in the relocation
149 : // entry provides the section to which the relocation will be applied.
150 496 : int Idx = it->first;
151 496 : uint64_t Addr = Sections[Idx].getLoadAddress();
152 : LLVM_DEBUG(dbgs() << "Resolving relocations Section #" << Idx << "\t"
153 : << format("%p", (uintptr_t)Addr) << "\n");
154 496 : resolveRelocationList(it->second, Addr);
155 : }
156 : Relocations.clear();
157 477 : }
158 :
159 218 : void RuntimeDyldImpl::mapSectionAddress(const void *LocalAddress,
160 : uint64_t TargetAddress) {
161 : MutexGuard locked(lock);
162 577 : for (unsigned i = 0, e = Sections.size(); i != e; ++i) {
163 1154 : if (Sections[i].getAddress() == LocalAddress) {
164 218 : reassignSectionAddress(i, TargetAddress);
165 218 : return;
166 : }
167 : }
168 0 : llvm_unreachable("Attempting to remap address of unknown section!");
169 : }
170 :
171 825 : static Error getOffset(const SymbolRef &Sym, SectionRef Sec,
172 : uint64_t &Result) {
173 : Expected<uint64_t> AddressOrErr = Sym.getAddress();
174 825 : if (!AddressOrErr)
175 : return AddressOrErr.takeError();
176 825 : Result = *AddressOrErr - Sec.getAddress();
177 : return Error::success();
178 : }
179 :
180 : Expected<RuntimeDyldImpl::ObjSectionToIDMap>
181 350 : RuntimeDyldImpl::loadObjectImpl(const object::ObjectFile &Obj) {
182 : MutexGuard locked(lock);
183 :
184 : // Save information about our target
185 350 : Arch = (Triple::ArchType)Obj.getArch();
186 350 : IsTargetLittleEndian = Obj.isLittleEndian();
187 350 : setMipsABI(Obj);
188 :
189 : // Compute the memory size required to load all sections to be loaded
190 : // and pass this information to the memory manager
191 350 : if (MemMgr.needsToReserveAllocationSpace()) {
192 31 : uint64_t CodeSize = 0, RODataSize = 0, RWDataSize = 0;
193 31 : uint32_t CodeAlign = 1, RODataAlign = 1, RWDataAlign = 1;
194 31 : if (auto Err = computeTotalAllocSize(Obj,
195 : CodeSize, CodeAlign,
196 : RODataSize, RODataAlign,
197 31 : RWDataSize, RWDataAlign))
198 : return std::move(Err);
199 62 : MemMgr.reserveAllocationSpace(CodeSize, CodeAlign, RODataSize, RODataAlign,
200 31 : RWDataSize, RWDataAlign);
201 : }
202 :
203 : // Used sections from the object file
204 : ObjSectionToIDMap LocalSections;
205 :
206 : // Common symbols requiring allocation, with their sizes and alignments
207 : CommonSymbolList CommonSymbolsToAllocate;
208 :
209 : uint64_t CommonSize = 0;
210 : uint32_t CommonAlign = 0;
211 :
212 : // First, collect all weak and common symbols. We need to know if stronger
213 : // definitions occur elsewhere.
214 : JITSymbolResolver::LookupSet ResponsibilitySet;
215 : {
216 : JITSymbolResolver::LookupSet Symbols;
217 2551 : for (auto &Sym : Obj.symbols()) {
218 2201 : uint32_t Flags = Sym.getFlags();
219 2201 : if ((Flags & SymbolRef::SF_Common) || (Flags & SymbolRef::SF_Weak)) {
220 : // Get symbol name.
221 98 : if (auto NameOrErr = Sym.getName())
222 : Symbols.insert(*NameOrErr);
223 : else
224 : return NameOrErr.takeError();
225 : }
226 : }
227 :
228 700 : if (auto ResultOrErr = Resolver.getResponsibilitySet(Symbols))
229 : ResponsibilitySet = std::move(*ResultOrErr);
230 : else
231 : return ResultOrErr.takeError();
232 : }
233 :
234 : // Parse symbols
235 : LLVM_DEBUG(dbgs() << "Parse symbols:\n");
236 2551 : for (symbol_iterator I = Obj.symbol_begin(), E = Obj.symbol_end(); I != E;
237 : ++I) {
238 2201 : uint32_t Flags = I->getFlags();
239 :
240 : // Skip undefined symbols.
241 2201 : if (Flags & SymbolRef::SF_Undefined)
242 653 : continue;
243 :
244 : // Get the symbol type.
245 : object::SymbolRef::Type SymType;
246 1637 : if (auto SymTypeOrErr = I->getType())
247 1637 : SymType = *SymTypeOrErr;
248 : else
249 : return SymTypeOrErr.takeError();
250 :
251 : // Get symbol name.
252 1637 : StringRef Name;
253 1637 : if (auto NameOrErr = I->getName())
254 1637 : Name = *NameOrErr;
255 : else
256 : return NameOrErr.takeError();
257 :
258 : // Compute JIT symbol flags.
259 1637 : auto JITSymFlags = getJITSymbolFlags(*I);
260 1637 : if (!JITSymFlags)
261 : return JITSymFlags.takeError();
262 :
263 : // If this is a weak definition, check to see if there's a strong one.
264 : // If there is, skip this symbol (we won't be providing it: the strong
265 : // definition will). If there's no strong definition, make this definition
266 : // strong.
267 3274 : if (JITSymFlags->isWeak() || JITSymFlags->isCommon()) {
268 : // First check whether there's already a definition in this instance.
269 195 : if (GlobalSymbolTable.count(Name))
270 1 : continue;
271 :
272 : // If we're not responsible for this symbol, skip it.
273 : if (!ResponsibilitySet.count(Name))
274 3 : continue;
275 :
276 : // Otherwise update the flags on the symbol to make this definition
277 : // strong.
278 188 : if (JITSymFlags->isWeak())
279 : *JITSymFlags &= ~JITSymbolFlags::Weak;
280 188 : if (JITSymFlags->isCommon()) {
281 : *JITSymFlags &= ~JITSymbolFlags::Common;
282 : uint32_t Align = I->getAlignment();
283 : uint64_t Size = I->getCommonSize();
284 85 : if (!CommonAlign)
285 : CommonAlign = Align;
286 85 : CommonSize = alignTo(CommonSize, Align) + Size;
287 85 : CommonSymbolsToAllocate.push_back(*I);
288 : }
289 : }
290 :
291 1633 : if (Flags & SymbolRef::SF_Absolute &&
292 : SymType != object::SymbolRef::ST_File) {
293 : uint64_t Addr = 0;
294 1 : if (auto AddrOrErr = I->getAddress())
295 1 : Addr = *AddrOrErr;
296 : else
297 : return AddrOrErr.takeError();
298 :
299 : unsigned SectionID = AbsoluteSymbolSection;
300 :
301 : LLVM_DEBUG(dbgs() << "\tType: " << SymType << " (absolute) Name: " << Name
302 : << " SID: " << SectionID
303 : << " Offset: " << format("%p", (uintptr_t)Addr)
304 : << " flags: " << Flags << "\n");
305 1 : GlobalSymbolTable[Name] = SymbolTableEntry(SectionID, Addr, *JITSymFlags);
306 3264 : } else if (SymType == object::SymbolRef::ST_Function ||
307 1632 : SymType == object::SymbolRef::ST_Data ||
308 1758 : SymType == object::SymbolRef::ST_Unknown ||
309 879 : SymType == object::SymbolRef::ST_Other) {
310 :
311 910 : section_iterator SI = Obj.section_end();
312 910 : if (auto SIOrErr = I->getSection())
313 910 : SI = *SIOrErr;
314 : else
315 : return SIOrErr.takeError();
316 :
317 910 : if (SI == Obj.section_end())
318 85 : continue;
319 :
320 : // Get symbol offset.
321 : uint64_t SectOffset;
322 1650 : if (auto Err = getOffset(*I, *SI, SectOffset))
323 : return std::move(Err);
324 :
325 825 : bool IsCode = SI->isText();
326 : unsigned SectionID;
327 825 : if (auto SectionIDOrErr =
328 825 : findOrEmitSection(Obj, *SI, IsCode, LocalSections))
329 825 : SectionID = *SectionIDOrErr;
330 : else
331 : return SectionIDOrErr.takeError();
332 :
333 : LLVM_DEBUG(dbgs() << "\tType: " << SymType << " Name: " << Name
334 : << " SID: " << SectionID
335 : << " Offset: " << format("%p", (uintptr_t)SectOffset)
336 : << " flags: " << Flags << "\n");
337 825 : GlobalSymbolTable[Name] =
338 825 : SymbolTableEntry(SectionID, SectOffset, *JITSymFlags);
339 : }
340 : }
341 :
342 : // Allocate common symbols
343 350 : if (auto Err = emitCommonSymbols(Obj, CommonSymbolsToAllocate, CommonSize,
344 350 : CommonAlign))
345 : return std::move(Err);
346 :
347 : // Parse and process relocations
348 : LLVM_DEBUG(dbgs() << "Parse relocations:\n");
349 350 : for (section_iterator SI = Obj.section_begin(), SE = Obj.section_end();
350 3184 : SI != SE; ++SI) {
351 : StubMap Stubs;
352 2834 : section_iterator RelocatedSection = SI->getRelocatedSection();
353 :
354 2834 : if (RelocatedSection == SE)
355 : continue;
356 :
357 613 : relocation_iterator I = SI->relocation_begin();
358 613 : relocation_iterator E = SI->relocation_end();
359 :
360 613 : if (I == E && !ProcessAllSections)
361 : continue;
362 :
363 583 : bool IsCode = RelocatedSection->isText();
364 : unsigned SectionID = 0;
365 583 : if (auto SectionIDOrErr = findOrEmitSection(Obj, *RelocatedSection, IsCode,
366 583 : LocalSections))
367 583 : SectionID = *SectionIDOrErr;
368 : else
369 : return SectionIDOrErr.takeError();
370 :
371 : LLVM_DEBUG(dbgs() << "\tSectionID: " << SectionID << "\n");
372 :
373 1917 : for (; I != E;)
374 1334 : if (auto IOrErr = processRelocationRef(SectionID, I, Obj, LocalSections, Stubs))
375 1334 : I = *IOrErr;
376 : else
377 : return IOrErr.takeError();
378 :
379 : // If there is an attached checker, notify it about the stubs for this
380 : // section so that they can be verified.
381 583 : if (Checker)
382 118 : Checker->registerStubMap(Obj.getFileName(), SectionID, Stubs);
383 : }
384 :
385 : // Give the subclasses a chance to tie-up any loose ends.
386 700 : if (auto Err = finalizeLoad(Obj, LocalSections))
387 : return std::move(Err);
388 :
389 : // for (auto E : LocalSections)
390 : // llvm::dbgs() << "Added: " << E.first.getRawDataRefImpl() << " -> " << E.second << "\n";
391 :
392 : return LocalSections;
393 : }
394 :
395 : // A helper method for computeTotalAllocSize.
396 : // Computes the memory size required to allocate sections with the given sizes,
397 : // assuming that all sections are allocated with the given alignment
398 : static uint64_t
399 : computeAllocationSizeForSections(std::vector<uint64_t> &SectionSizes,
400 : uint64_t Alignment) {
401 : uint64_t TotalSize = 0;
402 160 : for (size_t Idx = 0, Cnt = SectionSizes.size(); Idx < Cnt; Idx++) {
403 : uint64_t AlignedSize =
404 67 : (SectionSizes[Idx] + Alignment - 1) / Alignment * Alignment;
405 67 : TotalSize += AlignedSize;
406 : }
407 : return TotalSize;
408 : }
409 :
410 1044 : static bool isRequiredForExecution(const SectionRef Section) {
411 1044 : const ObjectFile *Obj = Section.getObject();
412 1044 : if (isa<object::ELFObjectFileBase>(Obj))
413 987 : return ELFSectionRef(Section).getFlags() & ELF::SHF_ALLOC;
414 : if (auto *COFFObj = dyn_cast<object::COFFObjectFile>(Obj)) {
415 17 : const coff_section *CoffSection = COFFObj->getCOFFSection(Section);
416 : // Avoid loading zero-sized COFF sections.
417 : // In PE files, VirtualSize gives the section size, and SizeOfRawData
418 : // may be zero for sections with content. In Obj files, SizeOfRawData
419 : // gives the section size, and VirtualSize is always zero. Hence
420 : // the need to check for both cases below.
421 : bool HasContent =
422 17 : (CoffSection->VirtualSize > 0) || (CoffSection->SizeOfRawData > 0);
423 : bool IsDiscardable =
424 17 : CoffSection->Characteristics &
425 : (COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_LNK_INFO);
426 17 : return HasContent && !IsDiscardable;
427 : }
428 :
429 : assert(isa<MachOObjectFile>(Obj));
430 : return true;
431 : }
432 :
433 880 : static bool isReadOnlyData(const SectionRef Section) {
434 880 : const ObjectFile *Obj = Section.getObject();
435 880 : if (isa<object::ELFObjectFileBase>(Obj))
436 1646 : return !(ELFSectionRef(Section).getFlags() &
437 823 : (ELF::SHF_WRITE | ELF::SHF_EXECINSTR));
438 : if (auto *COFFObj = dyn_cast<object::COFFObjectFile>(Obj))
439 17 : return ((COFFObj->getCOFFSection(Section)->Characteristics &
440 : (COFF::IMAGE_SCN_CNT_INITIALIZED_DATA
441 : | COFF::IMAGE_SCN_MEM_READ
442 : | COFF::IMAGE_SCN_MEM_WRITE))
443 : ==
444 : (COFF::IMAGE_SCN_CNT_INITIALIZED_DATA
445 17 : | COFF::IMAGE_SCN_MEM_READ));
446 :
447 : assert(isa<MachOObjectFile>(Obj));
448 : return false;
449 : }
450 :
451 821 : static bool isZeroInit(const SectionRef Section) {
452 821 : const ObjectFile *Obj = Section.getObject();
453 821 : if (isa<object::ELFObjectFileBase>(Obj))
454 764 : return ELFSectionRef(Section).getType() == ELF::SHT_NOBITS;
455 : if (auto *COFFObj = dyn_cast<object::COFFObjectFile>(Obj))
456 17 : return COFFObj->getCOFFSection(Section)->Characteristics &
457 17 : COFF::IMAGE_SCN_CNT_UNINITIALIZED_DATA;
458 :
459 : auto *MachO = cast<MachOObjectFile>(Obj);
460 40 : unsigned SectionType = MachO->getSectionType(Section);
461 40 : return SectionType == MachO::S_ZEROFILL ||
462 40 : SectionType == MachO::S_GB_ZEROFILL;
463 : }
464 :
465 : // Compute an upper bound of the memory size that is required to load all
466 : // sections
467 31 : Error RuntimeDyldImpl::computeTotalAllocSize(const ObjectFile &Obj,
468 : uint64_t &CodeSize,
469 : uint32_t &CodeAlign,
470 : uint64_t &RODataSize,
471 : uint32_t &RODataAlign,
472 : uint64_t &RWDataSize,
473 : uint32_t &RWDataAlign) {
474 : // Compute the size of all sections required for execution
475 : std::vector<uint64_t> CodeSectionSizes;
476 : std::vector<uint64_t> ROSectionSizes;
477 : std::vector<uint64_t> RWSectionSizes;
478 :
479 : // Collect sizes of all sections to be loaded;
480 : // also determine the max alignment of all sections
481 31 : for (section_iterator SI = Obj.section_begin(), SE = Obj.section_end();
482 254 : SI != SE; ++SI) {
483 : const SectionRef &Section = *SI;
484 :
485 223 : bool IsRequired = isRequiredForExecution(Section) || ProcessAllSections;
486 :
487 : // Consider only the sections that are required to be loaded for execution
488 : if (IsRequired) {
489 59 : uint64_t DataSize = Section.getSize();
490 59 : uint64_t Alignment64 = Section.getAlignment();
491 59 : unsigned Alignment = (unsigned)Alignment64 & 0xffffffffL;
492 59 : bool IsCode = Section.isText();
493 59 : bool IsReadOnly = isReadOnlyData(Section);
494 :
495 59 : StringRef Name;
496 59 : if (auto EC = Section.getName(Name))
497 0 : return errorCodeToError(EC);
498 :
499 59 : uint64_t StubBufSize = computeSectionStubBufSize(Obj, Section);
500 59 : uint64_t SectionSize = DataSize + StubBufSize;
501 :
502 : // The .eh_frame section (at least on Linux) needs an extra four bytes
503 : // padded
504 : // with zeroes added at the end. For MachO objects, this section has a
505 : // slightly different name, so this won't have any effect for MachO
506 : // objects.
507 : if (Name == ".eh_frame")
508 5 : SectionSize += 4;
509 :
510 59 : if (!SectionSize)
511 0 : SectionSize = 1;
512 :
513 59 : if (IsCode) {
514 31 : CodeAlign = std::max(CodeAlign, Alignment);
515 31 : CodeSectionSizes.push_back(SectionSize);
516 28 : } else if (IsReadOnly) {
517 17 : RODataAlign = std::max(RODataAlign, Alignment);
518 17 : ROSectionSizes.push_back(SectionSize);
519 : } else {
520 11 : RWDataAlign = std::max(RWDataAlign, Alignment);
521 11 : RWSectionSizes.push_back(SectionSize);
522 : }
523 : }
524 : }
525 :
526 : // Compute Global Offset Table size. If it is not zero we
527 : // also update alignment, which is equal to a size of a
528 : // single GOT entry.
529 31 : if (unsigned GotSize = computeGOTSize(Obj)) {
530 4 : RWSectionSizes.push_back(GotSize);
531 6 : RWDataAlign = std::max<uint32_t>(RWDataAlign, getGOTEntrySize());
532 : }
533 :
534 : // Compute the size of all common symbols
535 31 : uint64_t CommonSize = 0;
536 31 : uint32_t CommonAlign = 1;
537 205 : for (symbol_iterator I = Obj.symbol_begin(), E = Obj.symbol_end(); I != E;
538 : ++I) {
539 174 : uint32_t Flags = I->getFlags();
540 174 : if (Flags & SymbolRef::SF_Common) {
541 : // Add the common symbols to a list. We'll allocate them all below.
542 : uint64_t Size = I->getCommonSize();
543 : uint32_t Align = I->getAlignment();
544 : // If this is the first common symbol, use its alignment as the alignment
545 : // for the common symbols section.
546 8 : if (CommonSize == 0)
547 4 : CommonAlign = Align;
548 16 : CommonSize = alignTo(CommonSize, Align) + Size;
549 : }
550 : }
551 31 : if (CommonSize != 0) {
552 4 : RWSectionSizes.push_back(CommonSize);
553 4 : RWDataAlign = std::max(RWDataAlign, CommonAlign);
554 : }
555 :
556 : // Compute the required allocation space for each different type of sections
557 : // (code, read-only data, read-write data) assuming that all sections are
558 : // allocated with the max alignment. Note that we cannot compute with the
559 : // individual alignments of the sections, because then the required size
560 : // depends on the order, in which the sections are allocated.
561 31 : CodeSize = computeAllocationSizeForSections(CodeSectionSizes, CodeAlign);
562 31 : RODataSize = computeAllocationSizeForSections(ROSectionSizes, RODataAlign);
563 62 : RWDataSize = computeAllocationSizeForSections(RWSectionSizes, RWDataAlign);
564 :
565 : return Error::success();
566 : }
567 :
568 : // compute GOT size
569 31 : unsigned RuntimeDyldImpl::computeGOTSize(const ObjectFile &Obj) {
570 31 : size_t GotEntrySize = getGOTEntrySize();
571 31 : if (!GotEntrySize)
572 : return 0;
573 :
574 : size_t GotSize = 0;
575 31 : for (section_iterator SI = Obj.section_begin(), SE = Obj.section_end();
576 254 : SI != SE; ++SI) {
577 :
578 321 : for (const RelocationRef &Reloc : SI->relocations())
579 98 : if (relocationNeedsGot(Reloc))
580 6 : GotSize += GotEntrySize;
581 : }
582 :
583 31 : return GotSize;
584 : }
585 :
586 : // compute stub buffer size for the given section
587 880 : unsigned RuntimeDyldImpl::computeSectionStubBufSize(const ObjectFile &Obj,
588 : const SectionRef &Section) {
589 880 : unsigned StubSize = getMaxStubSize();
590 880 : if (StubSize == 0) {
591 : return 0;
592 : }
593 : // FIXME: this is an inefficient way to handle this. We should computed the
594 : // necessary section allocation size in loadObject by walking all the sections
595 : // once.
596 : unsigned StubBufSize = 0;
597 871 : for (section_iterator SI = Obj.section_begin(), SE = Obj.section_end();
598 8830 : SI != SE; ++SI) {
599 7959 : section_iterator RelSecI = SI->getRelocatedSection();
600 15918 : if (!(RelSecI == Section))
601 7338 : continue;
602 :
603 2054 : for (const RelocationRef &Reloc : SI->relocations())
604 1433 : if (relocationNeedsStub(Reloc))
605 421 : StubBufSize += StubSize;
606 : }
607 :
608 : // Get section data size and alignment
609 871 : uint64_t DataSize = Section.getSize();
610 871 : uint64_t Alignment64 = Section.getAlignment();
611 :
612 : // Add stubbuf size alignment
613 871 : unsigned Alignment = (unsigned)Alignment64 & 0xffffffffL;
614 871 : unsigned StubAlignment = getStubAlignment();
615 871 : unsigned EndAlignment = (DataSize | Alignment) & -(DataSize | Alignment);
616 871 : if (StubAlignment > EndAlignment)
617 4 : StubBufSize += StubAlignment - EndAlignment;
618 : return StubBufSize;
619 : }
620 :
621 393 : uint64_t RuntimeDyldImpl::readBytesUnaligned(uint8_t *Src,
622 : unsigned Size) const {
623 : uint64_t Result = 0;
624 393 : if (IsTargetLittleEndian) {
625 282 : Src += Size - 1;
626 1600 : while (Size--)
627 1318 : Result = (Result << 8) | *Src--;
628 : } else
629 587 : while (Size--)
630 476 : Result = (Result << 8) | *Src++;
631 :
632 393 : return Result;
633 : }
634 :
635 259 : void RuntimeDyldImpl::writeBytesUnaligned(uint64_t Value, uint8_t *Dst,
636 : unsigned Size) const {
637 259 : if (IsTargetLittleEndian) {
638 1012 : while (Size--) {
639 836 : *Dst++ = Value & 0xFF;
640 836 : Value >>= 8;
641 : }
642 : } else {
643 83 : Dst += Size - 1;
644 439 : while (Size--) {
645 356 : *Dst-- = Value & 0xFF;
646 356 : Value >>= 8;
647 : }
648 : }
649 259 : }
650 :
651 : Expected<JITSymbolFlags>
652 1722 : RuntimeDyldImpl::getJITSymbolFlags(const SymbolRef &SR) {
653 1722 : return JITSymbolFlags::fromObjectSymbol(SR);
654 : }
655 :
656 350 : Error RuntimeDyldImpl::emitCommonSymbols(const ObjectFile &Obj,
657 : CommonSymbolList &SymbolsToAllocate,
658 : uint64_t CommonSize,
659 : uint32_t CommonAlign) {
660 350 : if (SymbolsToAllocate.empty())
661 : return Error::success();
662 :
663 : // Allocate memory for the section
664 25 : unsigned SectionID = Sections.size();
665 25 : uint8_t *Addr = MemMgr.allocateDataSection(CommonSize, CommonAlign, SectionID,
666 25 : "<common symbols>", false);
667 25 : if (!Addr)
668 0 : report_fatal_error("Unable to allocate memory for common symbols!");
669 : uint64_t Offset = 0;
670 25 : Sections.push_back(
671 25 : SectionEntry("<common symbols>", Addr, CommonSize, CommonSize, 0));
672 25 : memset(Addr, 0, CommonSize);
673 :
674 : LLVM_DEBUG(dbgs() << "emitCommonSection SectionID: " << SectionID
675 : << " new addr: " << format("%p", Addr)
676 : << " DataSize: " << CommonSize << "\n");
677 :
678 : // Assign the address of each symbol
679 110 : for (auto &Sym : SymbolsToAllocate) {
680 : uint32_t Align = Sym.getAlignment();
681 : uint64_t Size = Sym.getCommonSize();
682 : StringRef Name;
683 85 : if (auto NameOrErr = Sym.getName())
684 85 : Name = *NameOrErr;
685 : else
686 : return NameOrErr.takeError();
687 85 : if (Align) {
688 : // This symbol has an alignment requirement.
689 85 : uint64_t AlignOffset = OffsetToAlignment((uint64_t)Addr, Align);
690 85 : Addr += AlignOffset;
691 85 : Offset += AlignOffset;
692 : }
693 85 : auto JITSymFlags = getJITSymbolFlags(Sym);
694 :
695 85 : if (!JITSymFlags)
696 : return JITSymFlags.takeError();
697 :
698 : LLVM_DEBUG(dbgs() << "Allocating common symbol " << Name << " address "
699 : << format("%p", Addr) << "\n");
700 85 : GlobalSymbolTable[Name] =
701 : SymbolTableEntry(SectionID, Offset, std::move(*JITSymFlags));
702 85 : Offset += Size;
703 85 : Addr += Size;
704 : }
705 :
706 25 : if (Checker)
707 10 : Checker->registerSection(Obj.getFileName(), SectionID);
708 :
709 : return Error::success();
710 : }
711 :
712 : Expected<unsigned>
713 821 : RuntimeDyldImpl::emitSection(const ObjectFile &Obj,
714 : const SectionRef &Section,
715 : bool IsCode) {
716 821 : StringRef data;
717 821 : uint64_t Alignment64 = Section.getAlignment();
718 :
719 821 : unsigned Alignment = (unsigned)Alignment64 & 0xffffffffL;
720 : unsigned PaddingSize = 0;
721 : unsigned StubBufSize = 0;
722 821 : bool IsRequired = isRequiredForExecution(Section);
723 821 : bool IsVirtual = Section.isVirtual();
724 821 : bool IsZeroInit = isZeroInit(Section);
725 821 : bool IsReadOnly = isReadOnlyData(Section);
726 821 : uint64_t DataSize = Section.getSize();
727 :
728 821 : StringRef Name;
729 821 : if (auto EC = Section.getName(Name))
730 0 : return errorCodeToError(EC);
731 :
732 821 : StubBufSize = computeSectionStubBufSize(Obj, Section);
733 :
734 : // The .eh_frame section (at least on Linux) needs an extra four bytes padded
735 : // with zeroes added at the end. For MachO objects, this section has a
736 : // slightly different name, so this won't have any effect for MachO objects.
737 : if (Name == ".eh_frame")
738 : PaddingSize = 4;
739 :
740 : uintptr_t Allocate;
741 821 : unsigned SectionID = Sections.size();
742 : uint8_t *Addr;
743 : const char *pData = nullptr;
744 :
745 : // If this section contains any bits (i.e. isn't a virtual or bss section),
746 : // grab a reference to them.
747 821 : if (!IsVirtual && !IsZeroInit) {
748 : // In either case, set the location of the unrelocated section in memory,
749 : // since we still process relocations for it even if we're not applying them.
750 796 : if (auto EC = Section.getContents(data))
751 0 : return errorCodeToError(EC);
752 : pData = data.data();
753 : }
754 :
755 : // Code section alignment needs to be at least as high as stub alignment or
756 : // padding calculations may by incorrect when the section is remapped to a
757 : // higher alignment.
758 821 : if (IsCode) {
759 347 : Alignment = std::max(Alignment, getStubAlignment());
760 347 : if (StubBufSize > 0)
761 43 : PaddingSize += getStubAlignment() - 1;
762 : }
763 :
764 : // Some sections, such as debug info, don't need to be loaded for execution.
765 : // Process those only if explicitly requested.
766 821 : if (IsRequired || ProcessAllSections) {
767 803 : Allocate = DataSize + PaddingSize + StubBufSize;
768 803 : if (!Allocate)
769 : Allocate = 1;
770 803 : Addr = IsCode ? MemMgr.allocateCodeSection(Allocate, Alignment, SectionID,
771 347 : Name)
772 912 : : MemMgr.allocateDataSection(Allocate, Alignment, SectionID,
773 456 : Name, IsReadOnly);
774 803 : if (!Addr)
775 0 : report_fatal_error("Unable to allocate section memory!");
776 :
777 : // Zero-initialize or copy the data from the image
778 803 : if (IsZeroInit || IsVirtual)
779 25 : memset(Addr, 0, DataSize);
780 : else
781 778 : memcpy(Addr, pData, DataSize);
782 :
783 : // Fill in any extra bytes we allocated for padding
784 803 : if (PaddingSize != 0) {
785 256 : memset(Addr + DataSize, 0, PaddingSize);
786 : // Update the DataSize variable to include padding.
787 : DataSize += PaddingSize;
788 :
789 : // Align DataSize to stub alignment if we have any stubs (PaddingSize will
790 : // have been increased above to account for this).
791 256 : if (StubBufSize > 0)
792 19 : DataSize &= ~(getStubAlignment() - 1);
793 : }
794 :
795 : LLVM_DEBUG(dbgs() << "emitSection SectionID: " << SectionID << " Name: "
796 : << Name << " obj addr: " << format("%p", pData)
797 : << " new addr: " << format("%p", Addr) << " DataSize: "
798 : << DataSize << " StubBufSize: " << StubBufSize
799 : << " Allocate: " << Allocate << "\n");
800 : } else {
801 : // Even if we didn't load the section, we need to record an entry for it
802 : // to handle later processing (and by 'handle' I mean don't do anything
803 : // with these sections).
804 : Allocate = 0;
805 : Addr = nullptr;
806 : LLVM_DEBUG(
807 : dbgs() << "emitSection SectionID: " << SectionID << " Name: " << Name
808 : << " obj addr: " << format("%p", data.data()) << " new addr: 0"
809 : << " DataSize: " << DataSize << " StubBufSize: " << StubBufSize
810 : << " Allocate: " << Allocate << "\n");
811 : }
812 :
813 821 : Sections.push_back(
814 821 : SectionEntry(Name, Addr, DataSize, Allocate, (uintptr_t)pData));
815 :
816 : // Debug info sections are linked as if their load address was zero
817 821 : if (!IsRequired)
818 : Sections.back().setLoadAddress(0);
819 :
820 821 : if (Checker)
821 152 : Checker->registerSection(Obj.getFileName(), SectionID);
822 :
823 : return SectionID;
824 : }
825 :
826 : Expected<unsigned>
827 2190 : RuntimeDyldImpl::findOrEmitSection(const ObjectFile &Obj,
828 : const SectionRef &Section,
829 : bool IsCode,
830 : ObjSectionToIDMap &LocalSections) {
831 :
832 : unsigned SectionID = 0;
833 : ObjSectionToIDMap::iterator i = LocalSections.find(Section);
834 2190 : if (i != LocalSections.end())
835 1369 : SectionID = i->second;
836 : else {
837 821 : if (auto SectionIDOrErr = emitSection(Obj, Section, IsCode))
838 821 : SectionID = *SectionIDOrErr;
839 : else
840 : return SectionIDOrErr.takeError();
841 821 : LocalSections[Section] = SectionID;
842 : }
843 : return SectionID;
844 : }
845 :
846 1099 : void RuntimeDyldImpl::addRelocationForSection(const RelocationEntry &RE,
847 : unsigned SectionID) {
848 1099 : Relocations[SectionID].push_back(RE);
849 1099 : }
850 :
851 296 : void RuntimeDyldImpl::addRelocationForSymbol(const RelocationEntry &RE,
852 : StringRef SymbolName) {
853 : // Relocation by symbol. If the symbol is found in the global symbol table,
854 : // create an appropriate section relocation. Otherwise, add it to
855 : // ExternalSymbolRelocations.
856 296 : RTDyldSymbolTable::const_iterator Loc = GlobalSymbolTable.find(SymbolName);
857 592 : if (Loc == GlobalSymbolTable.end()) {
858 293 : ExternalSymbolRelocations[SymbolName].push_back(RE);
859 : } else {
860 : // Copy the RE since we want to modify its addend.
861 3 : RelocationEntry RECopy = RE;
862 : const auto &SymInfo = Loc->second;
863 3 : RECopy.Addend += SymInfo.getOffset();
864 3 : Relocations[SymInfo.getSectionID()].push_back(RECopy);
865 : }
866 296 : }
867 :
868 21 : uint8_t *RuntimeDyldImpl::createStubFunction(uint8_t *Addr,
869 : unsigned AbiVariant) {
870 21 : if (Arch == Triple::aarch64 || Arch == Triple::aarch64_be) {
871 : // This stub has to be able to access the full address space,
872 : // since symbol lookup won't necessarily find a handy, in-range,
873 : // PLT stub for functions which could be anywhere.
874 : // Stub can use ip0 (== x16) to calculate address
875 0 : writeBytesUnaligned(0xd2e00010, Addr, 4); // movz ip0, #:abs_g3:<addr>
876 0 : writeBytesUnaligned(0xf2c00010, Addr+4, 4); // movk ip0, #:abs_g2_nc:<addr>
877 0 : writeBytesUnaligned(0xf2a00010, Addr+8, 4); // movk ip0, #:abs_g1_nc:<addr>
878 0 : writeBytesUnaligned(0xf2800010, Addr+12, 4); // movk ip0, #:abs_g0_nc:<addr>
879 0 : writeBytesUnaligned(0xd61f0200, Addr+16, 4); // br ip0
880 :
881 0 : return Addr;
882 21 : } else if (Arch == Triple::arm || Arch == Triple::armeb) {
883 : // TODO: There is only ARM far stub now. We should add the Thumb stub,
884 : // and stubs for branches Thumb - ARM and ARM - Thumb.
885 0 : writeBytesUnaligned(0xe51ff004, Addr, 4); // ldr pc, [pc, #-4]
886 0 : return Addr + 4;
887 21 : } else if (IsMipsO32ABI || IsMipsN32ABI) {
888 : // 0: 3c190000 lui t9,%hi(addr).
889 : // 4: 27390000 addiu t9,t9,%lo(addr).
890 : // 8: 03200008 jr t9.
891 : // c: 00000000 nop.
892 : const unsigned LuiT9Instr = 0x3c190000, AdduiT9Instr = 0x27390000;
893 : const unsigned NopInstr = 0x0;
894 : unsigned JrT9Instr = 0x03200008;
895 4 : if ((AbiVariant & ELF::EF_MIPS_ARCH) == ELF::EF_MIPS_ARCH_32R6 ||
896 : (AbiVariant & ELF::EF_MIPS_ARCH) == ELF::EF_MIPS_ARCH_64R6)
897 : JrT9Instr = 0x03200009;
898 :
899 4 : writeBytesUnaligned(LuiT9Instr, Addr, 4);
900 4 : writeBytesUnaligned(AdduiT9Instr, Addr + 4, 4);
901 4 : writeBytesUnaligned(JrT9Instr, Addr + 8, 4);
902 4 : writeBytesUnaligned(NopInstr, Addr + 12, 4);
903 4 : return Addr;
904 17 : } else if (IsMipsN64ABI) {
905 : // 0: 3c190000 lui t9,%highest(addr).
906 : // 4: 67390000 daddiu t9,t9,%higher(addr).
907 : // 8: 0019CC38 dsll t9,t9,16.
908 : // c: 67390000 daddiu t9,t9,%hi(addr).
909 : // 10: 0019CC38 dsll t9,t9,16.
910 : // 14: 67390000 daddiu t9,t9,%lo(addr).
911 : // 18: 03200008 jr t9.
912 : // 1c: 00000000 nop.
913 : const unsigned LuiT9Instr = 0x3c190000, DaddiuT9Instr = 0x67390000,
914 : DsllT9Instr = 0x19CC38;
915 : const unsigned NopInstr = 0x0;
916 : unsigned JrT9Instr = 0x03200008;
917 2 : if ((AbiVariant & ELF::EF_MIPS_ARCH) == ELF::EF_MIPS_ARCH_64R6)
918 : JrT9Instr = 0x03200009;
919 :
920 2 : writeBytesUnaligned(LuiT9Instr, Addr, 4);
921 2 : writeBytesUnaligned(DaddiuT9Instr, Addr + 4, 4);
922 2 : writeBytesUnaligned(DsllT9Instr, Addr + 8, 4);
923 2 : writeBytesUnaligned(DaddiuT9Instr, Addr + 12, 4);
924 2 : writeBytesUnaligned(DsllT9Instr, Addr + 16, 4);
925 2 : writeBytesUnaligned(DaddiuT9Instr, Addr + 20, 4);
926 2 : writeBytesUnaligned(JrT9Instr, Addr + 24, 4);
927 2 : writeBytesUnaligned(NopInstr, Addr + 28, 4);
928 2 : return Addr;
929 15 : } else if (Arch == Triple::ppc64 || Arch == Triple::ppc64le) {
930 : // Depending on which version of the ELF ABI is in use, we need to
931 : // generate one of two variants of the stub. They both start with
932 : // the same sequence to load the target address into r12.
933 3 : writeInt32BE(Addr, 0x3D800000); // lis r12, highest(addr)
934 3 : writeInt32BE(Addr+4, 0x618C0000); // ori r12, higher(addr)
935 3 : writeInt32BE(Addr+8, 0x798C07C6); // sldi r12, r12, 32
936 3 : writeInt32BE(Addr+12, 0x658C0000); // oris r12, r12, h(addr)
937 3 : writeInt32BE(Addr+16, 0x618C0000); // ori r12, r12, l(addr)
938 3 : if (AbiVariant == 2) {
939 : // PowerPC64 stub ELFv2 ABI: The address points to the function itself.
940 : // The address is already in r12 as required by the ABI. Branch to it.
941 3 : writeInt32BE(Addr+20, 0xF8410018); // std r2, 24(r1)
942 3 : writeInt32BE(Addr+24, 0x7D8903A6); // mtctr r12
943 3 : writeInt32BE(Addr+28, 0x4E800420); // bctr
944 : } else {
945 : // PowerPC64 stub ELFv1 ABI: The address points to a function descriptor.
946 : // Load the function address on r11 and sets it to control register. Also
947 : // loads the function TOC in r2 and environment pointer to r11.
948 0 : writeInt32BE(Addr+20, 0xF8410028); // std r2, 40(r1)
949 0 : writeInt32BE(Addr+24, 0xE96C0000); // ld r11, 0(r12)
950 0 : writeInt32BE(Addr+28, 0xE84C0008); // ld r2, 0(r12)
951 0 : writeInt32BE(Addr+32, 0x7D6903A6); // mtctr r11
952 0 : writeInt32BE(Addr+36, 0xE96C0010); // ld r11, 16(r2)
953 0 : writeInt32BE(Addr+40, 0x4E800420); // bctr
954 : }
955 3 : return Addr;
956 12 : } else if (Arch == Triple::systemz) {
957 : writeInt16BE(Addr, 0xC418); // lgrl %r1,.+8
958 : writeInt16BE(Addr+2, 0x0000);
959 : writeInt16BE(Addr+4, 0x0004);
960 : writeInt16BE(Addr+6, 0x07F1); // brc 15,%r1
961 : // 8-byte address stored at Addr + 8
962 0 : return Addr;
963 12 : } else if (Arch == Triple::x86_64) {
964 11 : *Addr = 0xFF; // jmp
965 11 : *(Addr+1) = 0x25; // rip
966 : // 32-bit PC-relative address of the GOT entry will be stored at Addr+2
967 1 : } else if (Arch == Triple::x86) {
968 1 : *Addr = 0xE9; // 32-bit pc-relative jump.
969 : }
970 : return Addr;
971 : }
972 :
973 : // Assign an address to a symbol name and resolve all the relocations
974 : // associated with it.
975 218 : void RuntimeDyldImpl::reassignSectionAddress(unsigned SectionID,
976 : uint64_t Addr) {
977 : // The address to use for relocation resolution is not
978 : // the address of the local section buffer. We must be doing
979 : // a remote execution environment of some sort. Relocations can't
980 : // be applied until all the sections have been moved. The client must
981 : // trigger this with a call to MCJIT::finalize() or
982 : // RuntimeDyld::resolveRelocations().
983 : //
984 : // Addr is a uint64_t because we can't assume the pointer width
985 : // of the target is the same as that of the host. Just use a generic
986 : // "big enough" type.
987 : LLVM_DEBUG(
988 : dbgs() << "Reassigning address for section " << SectionID << " ("
989 : << Sections[SectionID].getName() << "): "
990 : << format("0x%016" PRIx64, Sections[SectionID].getLoadAddress())
991 : << " -> " << format("0x%016" PRIx64, Addr) << "\n");
992 218 : Sections[SectionID].setLoadAddress(Addr);
993 218 : }
994 :
995 690 : void RuntimeDyldImpl::resolveRelocationList(const RelocationList &Relocs,
996 : uint64_t Value) {
997 2081 : for (unsigned i = 0, e = Relocs.size(); i != e; ++i) {
998 1391 : const RelocationEntry &RE = Relocs[i];
999 : // Ignore relocations for sections that were not loaded
1000 2782 : if (Sections[RE.SectionID].getAddress() == nullptr)
1001 : continue;
1002 1201 : resolveRelocation(RE, Value);
1003 : }
1004 690 : }
1005 :
1006 477 : void RuntimeDyldImpl::applyExternalSymbolRelocations(
1007 : const StringMap<JITEvaluatedSymbol> ExternalSymbolMap) {
1008 675 : while (!ExternalSymbolRelocations.empty()) {
1009 :
1010 198 : StringMap<RelocationList>::iterator i = ExternalSymbolRelocations.begin();
1011 :
1012 198 : StringRef Name = i->first();
1013 198 : if (Name.size() == 0) {
1014 : // This is an absolute symbol, use an address of zero.
1015 : LLVM_DEBUG(dbgs() << "Resolving absolute relocations."
1016 : << "\n");
1017 0 : RelocationList &Relocs = i->second;
1018 0 : resolveRelocationList(Relocs, 0);
1019 : } else {
1020 : uint64_t Addr = 0;
1021 198 : JITSymbolFlags Flags;
1022 198 : RTDyldSymbolTable::const_iterator Loc = GlobalSymbolTable.find(Name);
1023 396 : if (Loc == GlobalSymbolTable.end()) {
1024 159 : auto RRI = ExternalSymbolMap.find(Name);
1025 : assert(RRI != ExternalSymbolMap.end() && "No result for symbol");
1026 159 : Addr = RRI->second.getAddress();
1027 159 : Flags = RRI->second.getFlags();
1028 : // The call to getSymbolAddress may have caused additional modules to
1029 : // be loaded, which may have added new entries to the
1030 : // ExternalSymbolRelocations map. Consquently, we need to update our
1031 : // iterator. This is also why retrieval of the relocation list
1032 : // associated with this symbol is deferred until below this point.
1033 : // New entries may have been added to the relocation list.
1034 159 : i = ExternalSymbolRelocations.find(Name);
1035 : } else {
1036 : // We found the symbol in our global table. It was probably in a
1037 : // Module that we loaded previously.
1038 : const auto &SymInfo = Loc->second;
1039 39 : Addr = getSectionLoadAddress(SymInfo.getSectionID()) +
1040 39 : SymInfo.getOffset();
1041 39 : Flags = SymInfo.getFlags();
1042 : }
1043 :
1044 : // FIXME: Implement error handling that doesn't kill the host program!
1045 198 : if (!Addr)
1046 0 : report_fatal_error("Program used external function '" + Name +
1047 : "' which could not be resolved!");
1048 :
1049 : // If Resolver returned UINT64_MAX, the client wants to handle this symbol
1050 : // manually and we shouldn't resolve its relocations.
1051 198 : if (Addr != UINT64_MAX) {
1052 :
1053 : // Tweak the address based on the symbol flags if necessary.
1054 : // For example, this is used by RuntimeDyldMachOARM to toggle the low bit
1055 : // if the target symbol is Thumb.
1056 194 : Addr = modifyAddressBasedOnFlags(Addr, Flags);
1057 :
1058 : LLVM_DEBUG(dbgs() << "Resolving relocations Name: " << Name << "\t"
1059 : << format("0x%lx", Addr) << "\n");
1060 : // This list may have been updated when we called getSymbolAddress, so
1061 : // don't change this code to get the list earlier.
1062 194 : RelocationList &Relocs = i->second;
1063 194 : resolveRelocationList(Relocs, Addr);
1064 : }
1065 : }
1066 :
1067 : ExternalSymbolRelocations.erase(i);
1068 : }
1069 477 : }
1070 :
1071 446 : Error RuntimeDyldImpl::resolveExternalSymbols() {
1072 446 : StringMap<JITEvaluatedSymbol> ExternalSymbolMap;
1073 :
1074 : // Resolution can trigger emission of more symbols, so iterate until
1075 : // we've resolved *everything*.
1076 : {
1077 : JITSymbolResolver::LookupSet ResolvedSymbols;
1078 :
1079 : while (true) {
1080 : JITSymbolResolver::LookupSet NewSymbols;
1081 :
1082 1375 : for (auto &RelocKV : ExternalSymbolRelocations) {
1083 321 : StringRef Name = RelocKV.first();
1084 642 : if (!Name.empty() && !GlobalSymbolTable.count(Name) &&
1085 : !ResolvedSymbols.count(Name))
1086 : NewSymbols.insert(Name);
1087 : }
1088 :
1089 527 : if (NewSymbols.empty())
1090 : break;
1091 :
1092 : #ifdef _MSC_VER
1093 : using ExpectedLookupResult =
1094 : MSVCPExpected<JITSymbolResolver::LookupResult>;
1095 : #else
1096 : using ExpectedLookupResult = Expected<JITSymbolResolver::LookupResult>;
1097 : #endif
1098 :
1099 : auto NewSymbolsP = std::make_shared<std::promise<ExpectedLookupResult>>();
1100 : auto NewSymbolsF = NewSymbolsP->get_future();
1101 162 : Resolver.lookup(NewSymbols,
1102 0 : [=](Expected<JITSymbolResolver::LookupResult> Result) {
1103 81 : NewSymbolsP->set_value(std::move(Result));
1104 81 : });
1105 :
1106 162 : auto NewResolverResults = NewSymbolsF.get();
1107 :
1108 81 : if (!NewResolverResults)
1109 0 : return NewResolverResults.takeError();
1110 :
1111 : assert(NewResolverResults->size() == NewSymbols.size() &&
1112 : "Should have errored on unresolved symbols");
1113 :
1114 226 : for (auto &RRKV : *NewResolverResults) {
1115 : assert(!ResolvedSymbols.count(RRKV.first) && "Redundant resolution?");
1116 145 : ExternalSymbolMap.insert(RRKV);
1117 145 : ResolvedSymbols.insert(RRKV.first);
1118 : }
1119 : }
1120 : }
1121 :
1122 446 : applyExternalSymbolRelocations(ExternalSymbolMap);
1123 :
1124 : return Error::success();
1125 : }
1126 :
1127 31 : void RuntimeDyldImpl::finalizeAsync(
1128 : std::unique_ptr<RuntimeDyldImpl> This, std::function<void(Error)> OnEmitted,
1129 : std::unique_ptr<MemoryBuffer> UnderlyingBuffer) {
1130 :
1131 : // FIXME: Move-capture OnRelocsApplied and UnderlyingBuffer once we have
1132 : // c++14.
1133 : auto SharedUnderlyingBuffer =
1134 : std::shared_ptr<MemoryBuffer>(std::move(UnderlyingBuffer));
1135 : auto SharedThis = std::shared_ptr<RuntimeDyldImpl>(std::move(This));
1136 : auto PostResolveContinuation =
1137 0 : [SharedThis, OnEmitted, SharedUnderlyingBuffer](
1138 : Expected<JITSymbolResolver::LookupResult> Result) {
1139 : if (!Result) {
1140 : OnEmitted(Result.takeError());
1141 : return;
1142 : }
1143 :
1144 : /// Copy the result into a StringMap, where the keys are held by value.
1145 : StringMap<JITEvaluatedSymbol> Resolved;
1146 : for (auto &KV : *Result)
1147 : Resolved[KV.first] = KV.second;
1148 :
1149 : SharedThis->applyExternalSymbolRelocations(Resolved);
1150 : SharedThis->resolveLocalRelocations();
1151 : SharedThis->registerEHFrames();
1152 : std::string ErrMsg;
1153 : if (SharedThis->MemMgr.finalizeMemory(&ErrMsg))
1154 : OnEmitted(make_error<StringError>(std::move(ErrMsg),
1155 : inconvertibleErrorCode()));
1156 : else
1157 : OnEmitted(Error::success());
1158 31 : };
1159 :
1160 : JITSymbolResolver::LookupSet Symbols;
1161 :
1162 88 : for (auto &RelocKV : SharedThis->ExternalSymbolRelocations) {
1163 26 : StringRef Name = RelocKV.first();
1164 : assert(!Name.empty() && "Symbol has no name?");
1165 : assert(!SharedThis->GlobalSymbolTable.count(Name) &&
1166 : "Name already processed. RuntimeDyld instances can not be re-used "
1167 : "when finalizing with finalizeAsync.");
1168 : Symbols.insert(Name);
1169 : }
1170 :
1171 31 : if (!Symbols.empty()) {
1172 42 : SharedThis->Resolver.lookup(Symbols, PostResolveContinuation);
1173 : } else
1174 17 : PostResolveContinuation(std::map<StringRef, JITEvaluatedSymbol>());
1175 31 : }
1176 :
1177 : //===----------------------------------------------------------------------===//
1178 : // RuntimeDyld class implementation
1179 :
1180 1102 : uint64_t RuntimeDyld::LoadedObjectInfo::getSectionLoadAddress(
1181 : const object::SectionRef &Sec) const {
1182 :
1183 : auto I = ObjSecToIDMap.find(Sec);
1184 1102 : if (I != ObjSecToIDMap.end())
1185 780 : return RTDyld.Sections[I->second].getLoadAddress();
1186 :
1187 : return 0;
1188 : }
1189 :
1190 0 : void RuntimeDyld::MemoryManager::anchor() {}
1191 0 : void JITSymbolResolver::anchor() {}
1192 0 : void LegacyJITSymbolResolver::anchor() {}
1193 :
1194 306 : RuntimeDyld::RuntimeDyld(RuntimeDyld::MemoryManager &MemMgr,
1195 306 : JITSymbolResolver &Resolver)
1196 306 : : MemMgr(MemMgr), Resolver(Resolver) {
1197 : // FIXME: There's a potential issue lurking here if a single instance of
1198 : // RuntimeDyld is used to load multiple objects. The current implementation
1199 : // associates a single memory manager with a RuntimeDyld instance. Even
1200 : // though the public class spawns a new 'impl' instance for each load,
1201 : // they share a single memory manager. This can become a problem when page
1202 : // permissions are applied.
1203 : Dyld = nullptr;
1204 306 : ProcessAllSections = false;
1205 306 : Checker = nullptr;
1206 306 : }
1207 :
1208 234 : RuntimeDyld::~RuntimeDyld() {}
1209 :
1210 : static std::unique_ptr<RuntimeDyldCOFF>
1211 : createRuntimeDyldCOFF(Triple::ArchType Arch, RuntimeDyld::MemoryManager &MM,
1212 : JITSymbolResolver &Resolver, bool ProcessAllSections,
1213 : RuntimeDyldCheckerImpl *Checker) {
1214 : std::unique_ptr<RuntimeDyldCOFF> Dyld =
1215 4 : RuntimeDyldCOFF::create(Arch, MM, Resolver);
1216 : Dyld->setProcessAllSections(ProcessAllSections);
1217 : Dyld->setRuntimeDyldChecker(Checker);
1218 : return Dyld;
1219 : }
1220 :
1221 : static std::unique_ptr<RuntimeDyldELF>
1222 : createRuntimeDyldELF(Triple::ArchType Arch, RuntimeDyld::MemoryManager &MM,
1223 : JITSymbolResolver &Resolver, bool ProcessAllSections,
1224 : RuntimeDyldCheckerImpl *Checker) {
1225 : std::unique_ptr<RuntimeDyldELF> Dyld =
1226 284 : RuntimeDyldELF::create(Arch, MM, Resolver);
1227 : Dyld->setProcessAllSections(ProcessAllSections);
1228 : Dyld->setRuntimeDyldChecker(Checker);
1229 : return Dyld;
1230 : }
1231 :
1232 : static std::unique_ptr<RuntimeDyldMachO>
1233 : createRuntimeDyldMachO(Triple::ArchType Arch, RuntimeDyld::MemoryManager &MM,
1234 : JITSymbolResolver &Resolver,
1235 : bool ProcessAllSections,
1236 : RuntimeDyldCheckerImpl *Checker) {
1237 : std::unique_ptr<RuntimeDyldMachO> Dyld =
1238 11 : RuntimeDyldMachO::create(Arch, MM, Resolver);
1239 : Dyld->setProcessAllSections(ProcessAllSections);
1240 : Dyld->setRuntimeDyldChecker(Checker);
1241 : return Dyld;
1242 : }
1243 :
1244 : std::unique_ptr<RuntimeDyld::LoadedObjectInfo>
1245 350 : RuntimeDyld::loadObject(const ObjectFile &Obj) {
1246 350 : if (!Dyld) {
1247 598 : if (Obj.isELF())
1248 : Dyld =
1249 284 : createRuntimeDyldELF(static_cast<Triple::ArchType>(Obj.getArch()),
1250 284 : MemMgr, Resolver, ProcessAllSections, Checker);
1251 15 : else if (Obj.isMachO())
1252 11 : Dyld = createRuntimeDyldMachO(
1253 11 : static_cast<Triple::ArchType>(Obj.getArch()), MemMgr, Resolver,
1254 11 : ProcessAllSections, Checker);
1255 4 : else if (Obj.isCOFF())
1256 4 : Dyld = createRuntimeDyldCOFF(
1257 4 : static_cast<Triple::ArchType>(Obj.getArch()), MemMgr, Resolver,
1258 4 : ProcessAllSections, Checker);
1259 : else
1260 0 : report_fatal_error("Incompatible object format!");
1261 : }
1262 :
1263 350 : if (!Dyld->isCompatibleFile(Obj))
1264 0 : report_fatal_error("Incompatible object format!");
1265 :
1266 350 : auto LoadedObjInfo = Dyld->loadObject(Obj);
1267 350 : MemMgr.notifyObjectLoaded(*this, Obj);
1268 350 : return LoadedObjInfo;
1269 : }
1270 :
1271 0 : void *RuntimeDyld::getSymbolLocalAddress(StringRef Name) const {
1272 0 : if (!Dyld)
1273 : return nullptr;
1274 0 : return Dyld->getSymbolLocalAddress(Name);
1275 : }
1276 :
1277 386 : JITEvaluatedSymbol RuntimeDyld::getSymbol(StringRef Name) const {
1278 386 : if (!Dyld)
1279 : return nullptr;
1280 352 : return Dyld->getSymbol(Name);
1281 : }
1282 :
1283 133 : std::map<StringRef, JITEvaluatedSymbol> RuntimeDyld::getSymbolTable() const {
1284 133 : if (!Dyld)
1285 0 : return std::map<StringRef, JITEvaluatedSymbol>();
1286 133 : return Dyld->getSymbolTable();
1287 : }
1288 :
1289 892 : void RuntimeDyld::resolveRelocations() { Dyld->resolveRelocations(); }
1290 :
1291 0 : void RuntimeDyld::reassignSectionAddress(unsigned SectionID, uint64_t Addr) {
1292 0 : Dyld->reassignSectionAddress(SectionID, Addr);
1293 0 : }
1294 :
1295 218 : void RuntimeDyld::mapSectionAddress(const void *LocalAddress,
1296 : uint64_t TargetAddress) {
1297 218 : Dyld->mapSectionAddress(LocalAddress, TargetAddress);
1298 218 : }
1299 :
1300 784 : bool RuntimeDyld::hasError() { return Dyld->hasError(); }
1301 :
1302 0 : StringRef RuntimeDyld::getErrorString() { return Dyld->getErrorString(); }
1303 :
1304 102 : void RuntimeDyld::finalizeWithMemoryManagerLocking() {
1305 102 : bool MemoryFinalizationLocked = MemMgr.FinalizationLocked;
1306 102 : MemMgr.FinalizationLocked = true;
1307 102 : resolveRelocations();
1308 102 : registerEHFrames();
1309 102 : if (!MemoryFinalizationLocked) {
1310 84 : MemMgr.finalizeMemory();
1311 84 : MemMgr.FinalizationLocked = false;
1312 : }
1313 102 : }
1314 :
1315 439 : void RuntimeDyld::registerEHFrames() {
1316 439 : if (Dyld)
1317 439 : Dyld->registerEHFrames();
1318 439 : }
1319 :
1320 49 : void RuntimeDyld::deregisterEHFrames() {
1321 49 : if (Dyld)
1322 46 : Dyld->deregisterEHFrames();
1323 49 : }
1324 : // FIXME: Kill this with fire once we have a new JIT linker: this is only here
1325 : // so that we can re-use RuntimeDyld's implementation without twisting the
1326 : // interface any further for ORC's purposes.
1327 31 : void jitLinkForORC(object::ObjectFile &Obj,
1328 : std::unique_ptr<MemoryBuffer> UnderlyingBuffer,
1329 : RuntimeDyld::MemoryManager &MemMgr,
1330 : JITSymbolResolver &Resolver, bool ProcessAllSections,
1331 : std::function<Error(
1332 : std::unique_ptr<RuntimeDyld::LoadedObjectInfo> LoadedObj,
1333 : std::map<StringRef, JITEvaluatedSymbol>)>
1334 : OnLoaded,
1335 : std::function<void(Error)> OnEmitted) {
1336 :
1337 62 : RuntimeDyld RTDyld(MemMgr, Resolver);
1338 : RTDyld.setProcessAllSections(ProcessAllSections);
1339 :
1340 31 : auto Info = RTDyld.loadObject(Obj);
1341 :
1342 31 : if (RTDyld.hasError()) {
1343 0 : OnEmitted(make_error<StringError>(RTDyld.getErrorString(),
1344 0 : inconvertibleErrorCode()));
1345 : return;
1346 : }
1347 :
1348 62 : if (auto Err = OnLoaded(std::move(Info), RTDyld.getSymbolTable()))
1349 0 : OnEmitted(std::move(Err));
1350 :
1351 93 : RuntimeDyldImpl::finalizeAsync(std::move(RTDyld.Dyld), std::move(OnEmitted),
1352 : std::move(UnderlyingBuffer));
1353 : }
1354 :
1355 : } // end namespace llvm
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