1 //===- FileAnalysis.cpp -----------------------------------------*- C++ -*-===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 
9 #include "FileAnalysis.h"
10 #include "GraphBuilder.h"
11 
12 #include "llvm/BinaryFormat/ELF.h"
13 #include "llvm/DebugInfo/DWARF/DWARFContext.h"
14 #include "llvm/MC/MCAsmInfo.h"
15 #include "llvm/MC/MCContext.h"
16 #include "llvm/MC/MCDisassembler/MCDisassembler.h"
17 #include "llvm/MC/MCInst.h"
18 #include "llvm/MC/MCInstPrinter.h"
19 #include "llvm/MC/MCInstrAnalysis.h"
20 #include "llvm/MC/MCInstrDesc.h"
21 #include "llvm/MC/MCInstrInfo.h"
22 #include "llvm/MC/MCObjectFileInfo.h"
23 #include "llvm/MC/MCRegisterInfo.h"
24 #include "llvm/MC/MCSubtargetInfo.h"
25 #include "llvm/MC/MCTargetOptions.h"
26 #include "llvm/Object/Binary.h"
27 #include "llvm/Object/COFF.h"
28 #include "llvm/Object/ELFObjectFile.h"
29 #include "llvm/Object/ObjectFile.h"
30 #include "llvm/Support/Casting.h"
31 #include "llvm/Support/CommandLine.h"
32 #include "llvm/Support/Error.h"
33 #include "llvm/Support/MemoryBuffer.h"
34 #include "llvm/Support/TargetRegistry.h"
35 #include "llvm/Support/TargetSelect.h"
36 #include "llvm/Support/raw_ostream.h"
37 
38 
39 using Instr = llvm::cfi_verify::FileAnalysis::Instr;
40 using LLVMSymbolizer = llvm::symbolize::LLVMSymbolizer;
41 
42 namespace llvm {
43 namespace cfi_verify {
44 
45 bool IgnoreDWARFFlag;
46 
47 static cl::opt<bool, true> IgnoreDWARFArg(
48     "ignore-dwarf",
49     cl::desc(
50         "Ignore all DWARF data. This relaxes the requirements for all "
51         "statically linked libraries to have been compiled with '-g', but "
52         "will result in false positives for 'CFI unprotected' instructions."),
53     cl::location(IgnoreDWARFFlag), cl::init(false));
54 
stringCFIProtectionStatus(CFIProtectionStatus Status)55 StringRef stringCFIProtectionStatus(CFIProtectionStatus Status) {
56   switch (Status) {
57   case CFIProtectionStatus::PROTECTED:
58     return "PROTECTED";
59   case CFIProtectionStatus::FAIL_NOT_INDIRECT_CF:
60     return "FAIL_NOT_INDIRECT_CF";
61   case CFIProtectionStatus::FAIL_ORPHANS:
62     return "FAIL_ORPHANS";
63   case CFIProtectionStatus::FAIL_BAD_CONDITIONAL_BRANCH:
64     return "FAIL_BAD_CONDITIONAL_BRANCH";
65   case CFIProtectionStatus::FAIL_REGISTER_CLOBBERED:
66     return "FAIL_REGISTER_CLOBBERED";
67   case CFIProtectionStatus::FAIL_INVALID_INSTRUCTION:
68     return "FAIL_INVALID_INSTRUCTION";
69   }
70   llvm_unreachable("Attempted to stringify an unknown enum value.");
71 }
72 
Create(StringRef Filename)73 Expected<FileAnalysis> FileAnalysis::Create(StringRef Filename) {
74   // Open the filename provided.
75   Expected<object::OwningBinary<object::Binary>> BinaryOrErr =
76       object::createBinary(Filename);
77   if (!BinaryOrErr)
78     return BinaryOrErr.takeError();
79 
80   // Construct the object and allow it to take ownership of the binary.
81   object::OwningBinary<object::Binary> Binary = std::move(BinaryOrErr.get());
82   FileAnalysis Analysis(std::move(Binary));
83 
84   Analysis.Object = dyn_cast<object::ObjectFile>(Analysis.Binary.getBinary());
85   if (!Analysis.Object)
86     return make_error<UnsupportedDisassembly>("Failed to cast object");
87 
88   switch (Analysis.Object->getArch()) {
89     case Triple::x86:
90     case Triple::x86_64:
91     case Triple::aarch64:
92     case Triple::aarch64_be:
93       break;
94     default:
95       return make_error<UnsupportedDisassembly>("Unsupported architecture.");
96   }
97 
98   Analysis.ObjectTriple = Analysis.Object->makeTriple();
99   Analysis.Features = Analysis.Object->getFeatures();
100 
101   // Init the rest of the object.
102   if (auto InitResponse = Analysis.initialiseDisassemblyMembers())
103     return std::move(InitResponse);
104 
105   if (auto SectionParseResponse = Analysis.parseCodeSections())
106     return std::move(SectionParseResponse);
107 
108   if (auto SymbolTableParseResponse = Analysis.parseSymbolTable())
109     return std::move(SymbolTableParseResponse);
110 
111   return std::move(Analysis);
112 }
113 
FileAnalysis(object::OwningBinary<object::Binary> Binary)114 FileAnalysis::FileAnalysis(object::OwningBinary<object::Binary> Binary)
115     : Binary(std::move(Binary)) {}
116 
FileAnalysis(const Triple & ObjectTriple,const SubtargetFeatures & Features)117 FileAnalysis::FileAnalysis(const Triple &ObjectTriple,
118                            const SubtargetFeatures &Features)
119     : ObjectTriple(ObjectTriple), Features(Features) {}
120 
121 const Instr *
getPrevInstructionSequential(const Instr & InstrMeta) const122 FileAnalysis::getPrevInstructionSequential(const Instr &InstrMeta) const {
123   std::map<uint64_t, Instr>::const_iterator KV =
124       Instructions.find(InstrMeta.VMAddress);
125   if (KV == Instructions.end() || KV == Instructions.begin())
126     return nullptr;
127 
128   if (!(--KV)->second.Valid)
129     return nullptr;
130 
131   return &KV->second;
132 }
133 
134 const Instr *
getNextInstructionSequential(const Instr & InstrMeta) const135 FileAnalysis::getNextInstructionSequential(const Instr &InstrMeta) const {
136   std::map<uint64_t, Instr>::const_iterator KV =
137       Instructions.find(InstrMeta.VMAddress);
138   if (KV == Instructions.end() || ++KV == Instructions.end())
139     return nullptr;
140 
141   if (!KV->second.Valid)
142     return nullptr;
143 
144   return &KV->second;
145 }
146 
usesRegisterOperand(const Instr & InstrMeta) const147 bool FileAnalysis::usesRegisterOperand(const Instr &InstrMeta) const {
148   for (const auto &Operand : InstrMeta.Instruction) {
149     if (Operand.isReg())
150       return true;
151   }
152   return false;
153 }
154 
getInstruction(uint64_t Address) const155 const Instr *FileAnalysis::getInstruction(uint64_t Address) const {
156   const auto &InstrKV = Instructions.find(Address);
157   if (InstrKV == Instructions.end())
158     return nullptr;
159 
160   return &InstrKV->second;
161 }
162 
getInstructionOrDie(uint64_t Address) const163 const Instr &FileAnalysis::getInstructionOrDie(uint64_t Address) const {
164   const auto &InstrKV = Instructions.find(Address);
165   assert(InstrKV != Instructions.end() && "Address doesn't exist.");
166   return InstrKV->second;
167 }
168 
isCFITrap(const Instr & InstrMeta) const169 bool FileAnalysis::isCFITrap(const Instr &InstrMeta) const {
170   const auto &InstrDesc = MII->get(InstrMeta.Instruction.getOpcode());
171   return InstrDesc.isTrap() || willTrapOnCFIViolation(InstrMeta);
172 }
173 
willTrapOnCFIViolation(const Instr & InstrMeta) const174 bool FileAnalysis::willTrapOnCFIViolation(const Instr &InstrMeta) const {
175   const auto &InstrDesc = MII->get(InstrMeta.Instruction.getOpcode());
176   if (!InstrDesc.isCall())
177     return false;
178   uint64_t Target;
179   if (!MIA->evaluateBranch(InstrMeta.Instruction, InstrMeta.VMAddress,
180                            InstrMeta.InstructionSize, Target))
181     return false;
182   return TrapOnFailFunctionAddresses.count(Target) > 0;
183 }
184 
canFallThrough(const Instr & InstrMeta) const185 bool FileAnalysis::canFallThrough(const Instr &InstrMeta) const {
186   if (!InstrMeta.Valid)
187     return false;
188 
189   if (isCFITrap(InstrMeta))
190     return false;
191 
192   const auto &InstrDesc = MII->get(InstrMeta.Instruction.getOpcode());
193   if (InstrDesc.mayAffectControlFlow(InstrMeta.Instruction, *RegisterInfo))
194     return InstrDesc.isConditionalBranch();
195 
196   return true;
197 }
198 
199 const Instr *
getDefiniteNextInstruction(const Instr & InstrMeta) const200 FileAnalysis::getDefiniteNextInstruction(const Instr &InstrMeta) const {
201   if (!InstrMeta.Valid)
202     return nullptr;
203 
204   if (isCFITrap(InstrMeta))
205     return nullptr;
206 
207   const auto &InstrDesc = MII->get(InstrMeta.Instruction.getOpcode());
208   const Instr *NextMetaPtr;
209   if (InstrDesc.mayAffectControlFlow(InstrMeta.Instruction, *RegisterInfo)) {
210     if (InstrDesc.isConditionalBranch())
211       return nullptr;
212 
213     uint64_t Target;
214     if (!MIA->evaluateBranch(InstrMeta.Instruction, InstrMeta.VMAddress,
215                              InstrMeta.InstructionSize, Target))
216       return nullptr;
217 
218     NextMetaPtr = getInstruction(Target);
219   } else {
220     NextMetaPtr =
221         getInstruction(InstrMeta.VMAddress + InstrMeta.InstructionSize);
222   }
223 
224   if (!NextMetaPtr || !NextMetaPtr->Valid)
225     return nullptr;
226 
227   return NextMetaPtr;
228 }
229 
230 std::set<const Instr *>
getDirectControlFlowXRefs(const Instr & InstrMeta) const231 FileAnalysis::getDirectControlFlowXRefs(const Instr &InstrMeta) const {
232   std::set<const Instr *> CFCrossReferences;
233   const Instr *PrevInstruction = getPrevInstructionSequential(InstrMeta);
234 
235   if (PrevInstruction && canFallThrough(*PrevInstruction))
236     CFCrossReferences.insert(PrevInstruction);
237 
238   const auto &TargetRefsKV = StaticBranchTargetings.find(InstrMeta.VMAddress);
239   if (TargetRefsKV == StaticBranchTargetings.end())
240     return CFCrossReferences;
241 
242   for (uint64_t SourceInstrAddress : TargetRefsKV->second) {
243     const auto &SourceInstrKV = Instructions.find(SourceInstrAddress);
244     if (SourceInstrKV == Instructions.end()) {
245       errs() << "Failed to find source instruction at address "
246              << format_hex(SourceInstrAddress, 2)
247              << " for the cross-reference to instruction at address "
248              << format_hex(InstrMeta.VMAddress, 2) << ".\n";
249       continue;
250     }
251 
252     CFCrossReferences.insert(&SourceInstrKV->second);
253   }
254 
255   return CFCrossReferences;
256 }
257 
258 const std::set<object::SectionedAddress> &
getIndirectInstructions() const259 FileAnalysis::getIndirectInstructions() const {
260   return IndirectInstructions;
261 }
262 
getRegisterInfo() const263 const MCRegisterInfo *FileAnalysis::getRegisterInfo() const {
264   return RegisterInfo.get();
265 }
266 
getMCInstrInfo() const267 const MCInstrInfo *FileAnalysis::getMCInstrInfo() const { return MII.get(); }
268 
getMCInstrAnalysis() const269 const MCInstrAnalysis *FileAnalysis::getMCInstrAnalysis() const {
270   return MIA.get();
271 }
272 
273 Expected<DIInliningInfo>
symbolizeInlinedCode(object::SectionedAddress Address)274 FileAnalysis::symbolizeInlinedCode(object::SectionedAddress Address) {
275   assert(Symbolizer != nullptr && "Symbolizer is invalid.");
276 
277   return Symbolizer->symbolizeInlinedCode(std::string(Object->getFileName()),
278                                           Address);
279 }
280 
281 CFIProtectionStatus
validateCFIProtection(const GraphResult & Graph) const282 FileAnalysis::validateCFIProtection(const GraphResult &Graph) const {
283   const Instr *InstrMetaPtr = getInstruction(Graph.BaseAddress);
284   if (!InstrMetaPtr)
285     return CFIProtectionStatus::FAIL_INVALID_INSTRUCTION;
286 
287   const auto &InstrDesc = MII->get(InstrMetaPtr->Instruction.getOpcode());
288   if (!InstrDesc.mayAffectControlFlow(InstrMetaPtr->Instruction, *RegisterInfo))
289     return CFIProtectionStatus::FAIL_NOT_INDIRECT_CF;
290 
291   if (!usesRegisterOperand(*InstrMetaPtr))
292     return CFIProtectionStatus::FAIL_NOT_INDIRECT_CF;
293 
294   if (!Graph.OrphanedNodes.empty())
295     return CFIProtectionStatus::FAIL_ORPHANS;
296 
297   for (const auto &BranchNode : Graph.ConditionalBranchNodes) {
298     if (!BranchNode.CFIProtection)
299       return CFIProtectionStatus::FAIL_BAD_CONDITIONAL_BRANCH;
300   }
301 
302   if (indirectCFOperandClobber(Graph) != Graph.BaseAddress)
303     return CFIProtectionStatus::FAIL_REGISTER_CLOBBERED;
304 
305   return CFIProtectionStatus::PROTECTED;
306 }
307 
indirectCFOperandClobber(const GraphResult & Graph) const308 uint64_t FileAnalysis::indirectCFOperandClobber(const GraphResult &Graph) const {
309   assert(Graph.OrphanedNodes.empty() && "Orphaned nodes should be empty.");
310 
311   // Get the set of registers we must check to ensure they're not clobbered.
312   const Instr &IndirectCF = getInstructionOrDie(Graph.BaseAddress);
313   DenseSet<unsigned> RegisterNumbers;
314   for (const auto &Operand : IndirectCF.Instruction) {
315     if (Operand.isReg())
316       RegisterNumbers.insert(Operand.getReg());
317   }
318   assert(RegisterNumbers.size() && "Zero register operands on indirect CF.");
319 
320   // Now check all branches to indirect CFs and ensure no clobbering happens.
321   for (const auto &Branch : Graph.ConditionalBranchNodes) {
322     uint64_t Node;
323     if (Branch.IndirectCFIsOnTargetPath)
324       Node = Branch.Target;
325     else
326       Node = Branch.Fallthrough;
327 
328     // Some architectures (e.g., AArch64) cannot load in an indirect branch, so
329     // we allow them one load.
330     bool canLoad = !MII->get(IndirectCF.Instruction.getOpcode()).mayLoad();
331 
332     // We walk backwards from the indirect CF.  It is the last node returned by
333     // Graph.flattenAddress, so we skip it since we already handled it.
334     DenseSet<unsigned> CurRegisterNumbers = RegisterNumbers;
335     std::vector<uint64_t> Nodes = Graph.flattenAddress(Node);
336     for (auto I = Nodes.rbegin() + 1, E = Nodes.rend(); I != E; ++I) {
337       Node = *I;
338       const Instr &NodeInstr = getInstructionOrDie(Node);
339       const auto &InstrDesc = MII->get(NodeInstr.Instruction.getOpcode());
340 
341       for (auto RI = CurRegisterNumbers.begin(), RE = CurRegisterNumbers.end();
342            RI != RE; ++RI) {
343         unsigned RegNum = *RI;
344         if (InstrDesc.hasDefOfPhysReg(NodeInstr.Instruction, RegNum,
345                                       *RegisterInfo)) {
346           if (!canLoad || !InstrDesc.mayLoad())
347             return Node;
348           canLoad = false;
349           CurRegisterNumbers.erase(RI);
350           // Add the registers this load reads to those we check for clobbers.
351           for (unsigned i = InstrDesc.getNumDefs(),
352                         e = InstrDesc.getNumOperands(); i != e; i++) {
353             const auto Operand = NodeInstr.Instruction.getOperand(i);
354             if (Operand.isReg())
355               CurRegisterNumbers.insert(Operand.getReg());
356           }
357           break;
358         }
359       }
360     }
361   }
362 
363   return Graph.BaseAddress;
364 }
365 
printInstruction(const Instr & InstrMeta,raw_ostream & OS) const366 void FileAnalysis::printInstruction(const Instr &InstrMeta,
367                                     raw_ostream &OS) const {
368   Printer->printInst(&InstrMeta.Instruction, 0, "", *SubtargetInfo.get(), OS);
369 }
370 
initialiseDisassemblyMembers()371 Error FileAnalysis::initialiseDisassemblyMembers() {
372   std::string TripleName = ObjectTriple.getTriple();
373   ArchName = "";
374   MCPU = "";
375   std::string ErrorString;
376 
377   Symbolizer.reset(new LLVMSymbolizer());
378 
379   ObjectTarget =
380       TargetRegistry::lookupTarget(ArchName, ObjectTriple, ErrorString);
381   if (!ObjectTarget)
382     return make_error<UnsupportedDisassembly>(
383         (Twine("Couldn't find target \"") + ObjectTriple.getTriple() +
384          "\", failed with error: " + ErrorString)
385             .str());
386 
387   RegisterInfo.reset(ObjectTarget->createMCRegInfo(TripleName));
388   if (!RegisterInfo)
389     return make_error<UnsupportedDisassembly>(
390         "Failed to initialise RegisterInfo.");
391 
392   MCTargetOptions MCOptions;
393   AsmInfo.reset(
394       ObjectTarget->createMCAsmInfo(*RegisterInfo, TripleName, MCOptions));
395   if (!AsmInfo)
396     return make_error<UnsupportedDisassembly>("Failed to initialise AsmInfo.");
397 
398   SubtargetInfo.reset(ObjectTarget->createMCSubtargetInfo(
399       TripleName, MCPU, Features.getString()));
400   if (!SubtargetInfo)
401     return make_error<UnsupportedDisassembly>(
402         "Failed to initialise SubtargetInfo.");
403 
404   MII.reset(ObjectTarget->createMCInstrInfo());
405   if (!MII)
406     return make_error<UnsupportedDisassembly>("Failed to initialise MII.");
407 
408   Context.reset(new MCContext(AsmInfo.get(), RegisterInfo.get(), &MOFI));
409 
410   Disassembler.reset(
411       ObjectTarget->createMCDisassembler(*SubtargetInfo, *Context));
412 
413   if (!Disassembler)
414     return make_error<UnsupportedDisassembly>(
415         "No disassembler available for target");
416 
417   MIA.reset(ObjectTarget->createMCInstrAnalysis(MII.get()));
418 
419   Printer.reset(ObjectTarget->createMCInstPrinter(
420       ObjectTriple, AsmInfo->getAssemblerDialect(), *AsmInfo, *MII,
421       *RegisterInfo));
422 
423   return Error::success();
424 }
425 
parseCodeSections()426 Error FileAnalysis::parseCodeSections() {
427   if (!IgnoreDWARFFlag) {
428     std::unique_ptr<DWARFContext> DWARF = DWARFContext::create(*Object);
429     if (!DWARF)
430       return make_error<StringError>("Could not create DWARF information.",
431                                      inconvertibleErrorCode());
432 
433     bool LineInfoValid = false;
434 
435     for (auto &Unit : DWARF->compile_units()) {
436       const auto &LineTable = DWARF->getLineTableForUnit(Unit.get());
437       if (LineTable && !LineTable->Rows.empty()) {
438         LineInfoValid = true;
439         break;
440       }
441     }
442 
443     if (!LineInfoValid)
444       return make_error<StringError>(
445           "DWARF line information missing. Did you compile with '-g'?",
446           inconvertibleErrorCode());
447   }
448 
449   for (const object::SectionRef &Section : Object->sections()) {
450     // Ensure only executable sections get analysed.
451     if (!(object::ELFSectionRef(Section).getFlags() & ELF::SHF_EXECINSTR))
452       continue;
453 
454     // Avoid checking the PLT since it produces spurious failures on AArch64
455     // when ignoring DWARF data.
456     Expected<StringRef> NameOrErr = Section.getName();
457     if (NameOrErr && *NameOrErr == ".plt")
458       continue;
459     consumeError(NameOrErr.takeError());
460 
461     Expected<StringRef> Contents = Section.getContents();
462     if (!Contents)
463       return Contents.takeError();
464     ArrayRef<uint8_t> SectionBytes = arrayRefFromStringRef(*Contents);
465 
466     parseSectionContents(SectionBytes,
467                          {Section.getAddress(), Section.getIndex()});
468   }
469   return Error::success();
470 }
471 
parseSectionContents(ArrayRef<uint8_t> SectionBytes,object::SectionedAddress Address)472 void FileAnalysis::parseSectionContents(ArrayRef<uint8_t> SectionBytes,
473                                         object::SectionedAddress Address) {
474   assert(Symbolizer && "Symbolizer is uninitialised.");
475   MCInst Instruction;
476   Instr InstrMeta;
477   uint64_t InstructionSize;
478 
479   for (uint64_t Byte = 0; Byte < SectionBytes.size();) {
480     bool ValidInstruction =
481         Disassembler->getInstruction(Instruction, InstructionSize,
482                                      SectionBytes.drop_front(Byte), 0,
483                                      outs()) == MCDisassembler::Success;
484 
485     Byte += InstructionSize;
486 
487     uint64_t VMAddress = Address.Address + Byte - InstructionSize;
488     InstrMeta.Instruction = Instruction;
489     InstrMeta.VMAddress = VMAddress;
490     InstrMeta.InstructionSize = InstructionSize;
491     InstrMeta.Valid = ValidInstruction;
492 
493     addInstruction(InstrMeta);
494 
495     if (!ValidInstruction)
496       continue;
497 
498     // Skip additional parsing for instructions that do not affect the control
499     // flow.
500     const auto &InstrDesc = MII->get(Instruction.getOpcode());
501     if (!InstrDesc.mayAffectControlFlow(Instruction, *RegisterInfo))
502       continue;
503 
504     uint64_t Target;
505     if (MIA->evaluateBranch(Instruction, VMAddress, InstructionSize, Target)) {
506       // If the target can be evaluated, it's not indirect.
507       StaticBranchTargetings[Target].push_back(VMAddress);
508       continue;
509     }
510 
511     if (!usesRegisterOperand(InstrMeta))
512       continue;
513 
514     if (InstrDesc.isReturn())
515       continue;
516 
517     // Check if this instruction exists in the range of the DWARF metadata.
518     if (!IgnoreDWARFFlag) {
519       auto LineInfo =
520           Symbolizer->symbolizeCode(std::string(Object->getFileName()),
521                                     {VMAddress, Address.SectionIndex});
522       if (!LineInfo) {
523         handleAllErrors(LineInfo.takeError(), [](const ErrorInfoBase &E) {
524           errs() << "Symbolizer failed to get line: " << E.message() << "\n";
525         });
526         continue;
527       }
528 
529       if (LineInfo->FileName == DILineInfo::BadString)
530         continue;
531     }
532 
533     IndirectInstructions.insert({VMAddress, Address.SectionIndex});
534   }
535 }
536 
addInstruction(const Instr & Instruction)537 void FileAnalysis::addInstruction(const Instr &Instruction) {
538   const auto &KV =
539       Instructions.insert(std::make_pair(Instruction.VMAddress, Instruction));
540   if (!KV.second) {
541     errs() << "Failed to add instruction at address "
542            << format_hex(Instruction.VMAddress, 2)
543            << ": Instruction at this address already exists.\n";
544     exit(EXIT_FAILURE);
545   }
546 }
547 
parseSymbolTable()548 Error FileAnalysis::parseSymbolTable() {
549   // Functions that will trap on CFI violations.
550   SmallSet<StringRef, 4> TrapOnFailFunctions;
551   TrapOnFailFunctions.insert("__cfi_slowpath");
552   TrapOnFailFunctions.insert("__cfi_slowpath_diag");
553   TrapOnFailFunctions.insert("abort");
554 
555   // Look through the list of symbols for functions that will trap on CFI
556   // violations.
557   for (auto &Sym : Object->symbols()) {
558     auto SymNameOrErr = Sym.getName();
559     if (!SymNameOrErr)
560       consumeError(SymNameOrErr.takeError());
561     else if (TrapOnFailFunctions.count(*SymNameOrErr) > 0) {
562       auto AddrOrErr = Sym.getAddress();
563       if (!AddrOrErr)
564         consumeError(AddrOrErr.takeError());
565       else
566         TrapOnFailFunctionAddresses.insert(*AddrOrErr);
567     }
568   }
569   if (auto *ElfObject = dyn_cast<object::ELFObjectFileBase>(Object)) {
570     for (const auto &Addr : ElfObject->getPltAddresses()) {
571       if (!Addr.first)
572         continue;
573       object::SymbolRef Sym(*Addr.first, Object);
574       auto SymNameOrErr = Sym.getName();
575       if (!SymNameOrErr)
576         consumeError(SymNameOrErr.takeError());
577       else if (TrapOnFailFunctions.count(*SymNameOrErr) > 0)
578         TrapOnFailFunctionAddresses.insert(Addr.second);
579     }
580   }
581   return Error::success();
582 }
583 
UnsupportedDisassembly(StringRef Text)584 UnsupportedDisassembly::UnsupportedDisassembly(StringRef Text)
585     : Text(std::string(Text)) {}
586 
587 char UnsupportedDisassembly::ID;
log(raw_ostream & OS) const588 void UnsupportedDisassembly::log(raw_ostream &OS) const {
589   OS << "Could not initialise disassembler: " << Text;
590 }
591 
convertToErrorCode() const592 std::error_code UnsupportedDisassembly::convertToErrorCode() const {
593   return std::error_code();
594 }
595 
596 } // namespace cfi_verify
597 } // namespace llvm
598