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1  //===- Win64EHDumper.cpp - Win64 EH Printer ---------------------*- 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  #include "Win64EHDumper.h"
11  #include "llvm-readobj.h"
12  #include "llvm/Object/COFF.h"
13  #include "llvm/Support/ErrorHandling.h"
14  #include "llvm/Support/Format.h"
15  
16  using namespace llvm;
17  using namespace llvm::object;
18  using namespace llvm::Win64EH;
19  
20  static const EnumEntry<unsigned> UnwindFlags[] = {
21    { "ExceptionHandler", UNW_ExceptionHandler },
22    { "TerminateHandler", UNW_TerminateHandler },
23    { "ChainInfo"       , UNW_ChainInfo        }
24  };
25  
26  static const EnumEntry<unsigned> UnwindOpInfo[] = {
27    { "RAX",  0 },
28    { "RCX",  1 },
29    { "RDX",  2 },
30    { "RBX",  3 },
31    { "RSP",  4 },
32    { "RBP",  5 },
33    { "RSI",  6 },
34    { "RDI",  7 },
35    { "R8",   8 },
36    { "R9",   9 },
37    { "R10", 10 },
38    { "R11", 11 },
39    { "R12", 12 },
40    { "R13", 13 },
41    { "R14", 14 },
42    { "R15", 15 }
43  };
44  
getOffsetOfLSDA(const UnwindInfo & UI)45  static uint64_t getOffsetOfLSDA(const UnwindInfo& UI) {
46    return static_cast<const char*>(UI.getLanguageSpecificData())
47           - reinterpret_cast<const char*>(&UI);
48  }
49  
getLargeSlotValue(ArrayRef<UnwindCode> UC)50  static uint32_t getLargeSlotValue(ArrayRef<UnwindCode> UC) {
51    if (UC.size() < 3)
52      return 0;
53    return UC[1].FrameOffset + (static_cast<uint32_t>(UC[2].FrameOffset) << 16);
54  }
55  
56  // Returns the name of the unwind code.
getUnwindCodeTypeName(uint8_t Code)57  static StringRef getUnwindCodeTypeName(uint8_t Code) {
58    switch (Code) {
59    default: llvm_unreachable("Invalid unwind code");
60    case UOP_PushNonVol: return "PUSH_NONVOL";
61    case UOP_AllocLarge: return "ALLOC_LARGE";
62    case UOP_AllocSmall: return "ALLOC_SMALL";
63    case UOP_SetFPReg: return "SET_FPREG";
64    case UOP_SaveNonVol: return "SAVE_NONVOL";
65    case UOP_SaveNonVolBig: return "SAVE_NONVOL_FAR";
66    case UOP_SaveXMM128: return "SAVE_XMM128";
67    case UOP_SaveXMM128Big: return "SAVE_XMM128_FAR";
68    case UOP_PushMachFrame: return "PUSH_MACHFRAME";
69    }
70  }
71  
72  // Returns the name of a referenced register.
getUnwindRegisterName(uint8_t Reg)73  static StringRef getUnwindRegisterName(uint8_t Reg) {
74    switch (Reg) {
75    default: llvm_unreachable("Invalid register");
76    case 0: return "RAX";
77    case 1: return "RCX";
78    case 2: return "RDX";
79    case 3: return "RBX";
80    case 4: return "RSP";
81    case 5: return "RBP";
82    case 6: return "RSI";
83    case 7: return "RDI";
84    case 8: return "R8";
85    case 9: return "R9";
86    case 10: return "R10";
87    case 11: return "R11";
88    case 12: return "R12";
89    case 13: return "R13";
90    case 14: return "R14";
91    case 15: return "R15";
92    }
93  }
94  
95  // Calculates the number of array slots required for the unwind code.
getNumUsedSlots(const UnwindCode & UnwindCode)96  static unsigned getNumUsedSlots(const UnwindCode &UnwindCode) {
97    switch (UnwindCode.getUnwindOp()) {
98    default: llvm_unreachable("Invalid unwind code");
99    case UOP_PushNonVol:
100    case UOP_AllocSmall:
101    case UOP_SetFPReg:
102    case UOP_PushMachFrame:
103      return 1;
104    case UOP_SaveNonVol:
105    case UOP_SaveXMM128:
106      return 2;
107    case UOP_SaveNonVolBig:
108    case UOP_SaveXMM128Big:
109      return 3;
110    case UOP_AllocLarge:
111      return (UnwindCode.getOpInfo() == 0) ? 2 : 3;
112    }
113  }
114  
formatSymbol(const Dumper::Context & Ctx,const coff_section * Section,uint64_t Offset,uint32_t Displacement)115  static std::string formatSymbol(const Dumper::Context &Ctx,
116                                  const coff_section *Section, uint64_t Offset,
117                                  uint32_t Displacement) {
118    std::string Buffer;
119    raw_string_ostream OS(Buffer);
120  
121    SymbolRef Symbol;
122    if (!Ctx.ResolveSymbol(Section, Offset, Symbol, Ctx.UserData)) {
123      if (ErrorOr<StringRef> Name = Symbol.getName()) {
124        OS << *Name;
125        if (Displacement > 0)
126          OS << format(" +0x%X (0x%" PRIX64 ")", Displacement, Offset);
127        else
128          OS << format(" (0x%" PRIX64 ")", Offset);
129        return OS.str();
130      }
131    }
132  
133    OS << format(" (0x%" PRIX64 ")", Offset);
134    return OS.str();
135  }
136  
resolveRelocation(const Dumper::Context & Ctx,const coff_section * Section,uint64_t Offset,const coff_section * & ResolvedSection,uint64_t & ResolvedAddress)137  static std::error_code resolveRelocation(const Dumper::Context &Ctx,
138                                           const coff_section *Section,
139                                           uint64_t Offset,
140                                           const coff_section *&ResolvedSection,
141                                           uint64_t &ResolvedAddress) {
142    SymbolRef Symbol;
143    if (std::error_code EC =
144            Ctx.ResolveSymbol(Section, Offset, Symbol, Ctx.UserData))
145      return EC;
146  
147    ErrorOr<uint64_t> ResolvedAddressOrErr = Symbol.getAddress();
148    if (std::error_code EC = ResolvedAddressOrErr.getError())
149      return EC;
150    ResolvedAddress = *ResolvedAddressOrErr;
151  
152    ErrorOr<section_iterator> SI = Symbol.getSection();
153    ResolvedSection = Ctx.COFF.getCOFFSection(**SI);
154    return std::error_code();
155  }
156  
157  namespace llvm {
158  namespace Win64EH {
printRuntimeFunctionEntry(const Context & Ctx,const coff_section * Section,uint64_t Offset,const RuntimeFunction & RF)159  void Dumper::printRuntimeFunctionEntry(const Context &Ctx,
160                                         const coff_section *Section,
161                                         uint64_t Offset,
162                                         const RuntimeFunction &RF) {
163    SW.printString("StartAddress",
164                   formatSymbol(Ctx, Section, Offset + 0, RF.StartAddress));
165    SW.printString("EndAddress",
166                   formatSymbol(Ctx, Section, Offset + 4, RF.EndAddress));
167    SW.printString("UnwindInfoAddress",
168                   formatSymbol(Ctx, Section, Offset + 8, RF.UnwindInfoOffset));
169  }
170  
171  // Prints one unwind code. Because an unwind code can occupy up to 3 slots in
172  // the unwind codes array, this function requires that the correct number of
173  // slots is provided.
printUnwindCode(const UnwindInfo & UI,ArrayRef<UnwindCode> UC)174  void Dumper::printUnwindCode(const UnwindInfo& UI, ArrayRef<UnwindCode> UC) {
175    assert(UC.size() >= getNumUsedSlots(UC[0]));
176  
177    SW.startLine() << format("0x%02X: ", unsigned(UC[0].u.CodeOffset))
178                   << getUnwindCodeTypeName(UC[0].getUnwindOp());
179  
180    switch (UC[0].getUnwindOp()) {
181    case UOP_PushNonVol:
182      OS << " reg=" << getUnwindRegisterName(UC[0].getOpInfo());
183      break;
184  
185    case UOP_AllocLarge:
186      OS << " size="
187         << ((UC[0].getOpInfo() == 0) ? UC[1].FrameOffset * 8
188                                      : getLargeSlotValue(UC));
189      break;
190  
191    case UOP_AllocSmall:
192      OS << " size=" << (UC[0].getOpInfo() + 1) * 8;
193      break;
194  
195    case UOP_SetFPReg:
196      if (UI.getFrameRegister() == 0)
197        OS << " reg=<invalid>";
198      else
199        OS << " reg=" << getUnwindRegisterName(UI.getFrameRegister())
200           << format(", offset=0x%X", UI.getFrameOffset() * 16);
201      break;
202  
203    case UOP_SaveNonVol:
204      OS << " reg=" << getUnwindRegisterName(UC[0].getOpInfo())
205         << format(", offset=0x%X", UC[1].FrameOffset * 8);
206      break;
207  
208    case UOP_SaveNonVolBig:
209      OS << " reg=" << getUnwindRegisterName(UC[0].getOpInfo())
210         << format(", offset=0x%X", getLargeSlotValue(UC));
211      break;
212  
213    case UOP_SaveXMM128:
214      OS << " reg=XMM" << static_cast<uint32_t>(UC[0].getOpInfo())
215         << format(", offset=0x%X", UC[1].FrameOffset * 16);
216      break;
217  
218    case UOP_SaveXMM128Big:
219      OS << " reg=XMM" << static_cast<uint32_t>(UC[0].getOpInfo())
220         << format(", offset=0x%X", getLargeSlotValue(UC));
221      break;
222  
223    case UOP_PushMachFrame:
224      OS << " errcode=" << (UC[0].getOpInfo() == 0 ? "no" : "yes");
225      break;
226    }
227  
228    OS << "\n";
229  }
230  
printUnwindInfo(const Context & Ctx,const coff_section * Section,off_t Offset,const UnwindInfo & UI)231  void Dumper::printUnwindInfo(const Context &Ctx, const coff_section *Section,
232                               off_t Offset, const UnwindInfo &UI) {
233    DictScope UIS(SW, "UnwindInfo");
234    SW.printNumber("Version", UI.getVersion());
235    SW.printFlags("Flags", UI.getFlags(), makeArrayRef(UnwindFlags));
236    SW.printNumber("PrologSize", UI.PrologSize);
237    if (UI.getFrameRegister()) {
238      SW.printEnum("FrameRegister", UI.getFrameRegister(),
239                   makeArrayRef(UnwindOpInfo));
240      SW.printHex("FrameOffset", UI.getFrameOffset());
241    } else {
242      SW.printString("FrameRegister", StringRef("-"));
243      SW.printString("FrameOffset", StringRef("-"));
244    }
245  
246    SW.printNumber("UnwindCodeCount", UI.NumCodes);
247    {
248      ListScope UCS(SW, "UnwindCodes");
249      ArrayRef<UnwindCode> UC(&UI.UnwindCodes[0], UI.NumCodes);
250      for (const UnwindCode *UCI = UC.begin(), *UCE = UC.end(); UCI < UCE; ++UCI) {
251        unsigned UsedSlots = getNumUsedSlots(*UCI);
252        if (UsedSlots > UC.size()) {
253          errs() << "corrupt unwind data";
254          return;
255        }
256  
257        printUnwindCode(UI, makeArrayRef(UCI, UCE));
258        UCI = UCI + UsedSlots - 1;
259      }
260    }
261  
262    uint64_t LSDAOffset = Offset + getOffsetOfLSDA(UI);
263    if (UI.getFlags() & (UNW_ExceptionHandler | UNW_TerminateHandler)) {
264      SW.printString("Handler",
265                     formatSymbol(Ctx, Section, LSDAOffset,
266                                  UI.getLanguageSpecificHandlerOffset()));
267    } else if (UI.getFlags() & UNW_ChainInfo) {
268      if (const RuntimeFunction *Chained = UI.getChainedFunctionEntry()) {
269        DictScope CS(SW, "Chained");
270        printRuntimeFunctionEntry(Ctx, Section, LSDAOffset, *Chained);
271      }
272    }
273  }
274  
printRuntimeFunction(const Context & Ctx,const coff_section * Section,uint64_t SectionOffset,const RuntimeFunction & RF)275  void Dumper::printRuntimeFunction(const Context &Ctx,
276                                    const coff_section *Section,
277                                    uint64_t SectionOffset,
278                                    const RuntimeFunction &RF) {
279    DictScope RFS(SW, "RuntimeFunction");
280    printRuntimeFunctionEntry(Ctx, Section, SectionOffset, RF);
281  
282    const coff_section *XData;
283    uint64_t Offset;
284    resolveRelocation(Ctx, Section, SectionOffset + 8, XData, Offset);
285  
286    ArrayRef<uint8_t> Contents;
287    error(Ctx.COFF.getSectionContents(XData, Contents));
288    if (Contents.empty())
289      return;
290  
291    Offset = Offset + RF.UnwindInfoOffset;
292    if (Offset > Contents.size())
293      return;
294  
295    const auto UI = reinterpret_cast<const UnwindInfo*>(Contents.data() + Offset);
296    printUnwindInfo(Ctx, XData, Offset, *UI);
297  }
298  
printData(const Context & Ctx)299  void Dumper::printData(const Context &Ctx) {
300    for (const auto &Section : Ctx.COFF.sections()) {
301      StringRef Name;
302      Section.getName(Name);
303  
304      if (Name != ".pdata" && !Name.startswith(".pdata$"))
305        continue;
306  
307      const coff_section *PData = Ctx.COFF.getCOFFSection(Section);
308      ArrayRef<uint8_t> Contents;
309      error(Ctx.COFF.getSectionContents(PData, Contents));
310      if (Contents.empty())
311        continue;
312  
313      const RuntimeFunction *Entries =
314        reinterpret_cast<const RuntimeFunction *>(Contents.data());
315      const size_t Count = Contents.size() / sizeof(RuntimeFunction);
316      ArrayRef<RuntimeFunction> RuntimeFunctions(Entries, Count);
317  
318      size_t Index = 0;
319      for (const auto &RF : RuntimeFunctions) {
320        printRuntimeFunction(Ctx, Ctx.COFF.getCOFFSection(Section),
321                             Index * sizeof(RuntimeFunction), RF);
322        ++Index;
323      }
324    }
325  }
326  }
327  }
328  
329