1 //===- Win64EHDumper.cpp - Win64 EH Printer ---------------------*- 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 "Win64EHDumper.h" 10 #include "llvm-readobj.h" 11 #include "llvm/Object/COFF.h" 12 #include "llvm/Support/ErrorHandling.h" 13 #include "llvm/Support/Format.h" 14 15 using namespace llvm; 16 using namespace llvm::object; 17 using namespace llvm::Win64EH; 18 19 static const EnumEntry<unsigned> UnwindFlags[] = { 20 { "ExceptionHandler", UNW_ExceptionHandler }, 21 { "TerminateHandler", UNW_TerminateHandler }, 22 { "ChainInfo" , UNW_ChainInfo } 23 }; 24 25 static const EnumEntry<unsigned> UnwindOpInfo[] = { 26 { "RAX", 0 }, 27 { "RCX", 1 }, 28 { "RDX", 2 }, 29 { "RBX", 3 }, 30 { "RSP", 4 }, 31 { "RBP", 5 }, 32 { "RSI", 6 }, 33 { "RDI", 7 }, 34 { "R8", 8 }, 35 { "R9", 9 }, 36 { "R10", 10 }, 37 { "R11", 11 }, 38 { "R12", 12 }, 39 { "R13", 13 }, 40 { "R14", 14 }, 41 { "R15", 15 } 42 }; 43 44 static uint64_t getOffsetOfLSDA(const UnwindInfo& UI) { 45 return static_cast<const char*>(UI.getLanguageSpecificData()) 46 - reinterpret_cast<const char*>(&UI); 47 } 48 49 static uint32_t getLargeSlotValue(ArrayRef<UnwindCode> UC) { 50 if (UC.size() < 3) 51 return 0; 52 return UC[1].FrameOffset + (static_cast<uint32_t>(UC[2].FrameOffset) << 16); 53 } 54 55 // Returns the name of the unwind code. 56 static StringRef getUnwindCodeTypeName(uint8_t Code) { 57 switch (Code) { 58 default: llvm_unreachable("Invalid unwind code"); 59 case UOP_PushNonVol: return "PUSH_NONVOL"; 60 case UOP_AllocLarge: return "ALLOC_LARGE"; 61 case UOP_AllocSmall: return "ALLOC_SMALL"; 62 case UOP_SetFPReg: return "SET_FPREG"; 63 case UOP_SaveNonVol: return "SAVE_NONVOL"; 64 case UOP_SaveNonVolBig: return "SAVE_NONVOL_FAR"; 65 case UOP_SaveXMM128: return "SAVE_XMM128"; 66 case UOP_SaveXMM128Big: return "SAVE_XMM128_FAR"; 67 case UOP_PushMachFrame: return "PUSH_MACHFRAME"; 68 } 69 } 70 71 // Returns the name of a referenced register. 72 static StringRef getUnwindRegisterName(uint8_t Reg) { 73 switch (Reg) { 74 default: llvm_unreachable("Invalid register"); 75 case 0: return "RAX"; 76 case 1: return "RCX"; 77 case 2: return "RDX"; 78 case 3: return "RBX"; 79 case 4: return "RSP"; 80 case 5: return "RBP"; 81 case 6: return "RSI"; 82 case 7: return "RDI"; 83 case 8: return "R8"; 84 case 9: return "R9"; 85 case 10: return "R10"; 86 case 11: return "R11"; 87 case 12: return "R12"; 88 case 13: return "R13"; 89 case 14: return "R14"; 90 case 15: return "R15"; 91 } 92 } 93 94 // Calculates the number of array slots required for the unwind code. 95 static unsigned getNumUsedSlots(const UnwindCode &UnwindCode) { 96 switch (UnwindCode.getUnwindOp()) { 97 default: llvm_unreachable("Invalid unwind code"); 98 case UOP_PushNonVol: 99 case UOP_AllocSmall: 100 case UOP_SetFPReg: 101 case UOP_PushMachFrame: 102 return 1; 103 case UOP_SaveNonVol: 104 case UOP_SaveXMM128: 105 return 2; 106 case UOP_SaveNonVolBig: 107 case UOP_SaveXMM128Big: 108 return 3; 109 case UOP_AllocLarge: 110 return (UnwindCode.getOpInfo() == 0) ? 2 : 3; 111 } 112 } 113 114 static std::error_code getSymbol(const COFFObjectFile &COFF, uint64_t VA, 115 object::SymbolRef &Sym) { 116 for (const auto &Symbol : COFF.symbols()) { 117 Expected<uint64_t> Address = Symbol.getAddress(); 118 if (!Address) 119 return errorToErrorCode(Address.takeError()); 120 if (*Address == VA) { 121 Sym = Symbol; 122 return std::error_code(); 123 } 124 } 125 return inconvertibleErrorCode(); 126 } 127 128 static std::string formatSymbol(const Dumper::Context &Ctx, 129 const coff_section *Section, uint64_t Offset, 130 uint32_t Displacement) { 131 std::string Buffer; 132 raw_string_ostream OS(Buffer); 133 134 SymbolRef Symbol; 135 if (!Ctx.ResolveSymbol(Section, Offset, Symbol, Ctx.UserData)) { 136 Expected<StringRef> Name = Symbol.getName(); 137 if (Name) { 138 OS << *Name; 139 if (Displacement > 0) 140 OS << format(" +0x%X (0x%" PRIX64 ")", Displacement, Offset); 141 else 142 OS << format(" (0x%" PRIX64 ")", Offset); 143 return OS.str(); 144 } else { 145 // TODO: Actually report errors helpfully. 146 consumeError(Name.takeError()); 147 } 148 } else if (!getSymbol(Ctx.COFF, Ctx.COFF.getImageBase() + Displacement, 149 Symbol)) { 150 Expected<StringRef> Name = Symbol.getName(); 151 if (Name) { 152 OS << *Name; 153 OS << format(" (0x%" PRIX64 ")", Ctx.COFF.getImageBase() + Displacement); 154 return OS.str(); 155 } else { 156 consumeError(Name.takeError()); 157 } 158 } 159 160 if (Displacement > 0) 161 OS << format("(0x%" PRIX64 ")", Ctx.COFF.getImageBase() + Displacement); 162 else 163 OS << format("(0x%" PRIX64 ")", Offset); 164 return OS.str(); 165 } 166 167 static std::error_code resolveRelocation(const Dumper::Context &Ctx, 168 const coff_section *Section, 169 uint64_t Offset, 170 const coff_section *&ResolvedSection, 171 uint64_t &ResolvedAddress) { 172 SymbolRef Symbol; 173 if (std::error_code EC = 174 Ctx.ResolveSymbol(Section, Offset, Symbol, Ctx.UserData)) 175 return EC; 176 177 Expected<uint64_t> ResolvedAddressOrErr = Symbol.getAddress(); 178 if (!ResolvedAddressOrErr) 179 return errorToErrorCode(ResolvedAddressOrErr.takeError()); 180 ResolvedAddress = *ResolvedAddressOrErr; 181 182 Expected<section_iterator> SI = Symbol.getSection(); 183 if (!SI) 184 return errorToErrorCode(SI.takeError()); 185 ResolvedSection = Ctx.COFF.getCOFFSection(**SI); 186 return std::error_code(); 187 } 188 189 static const object::coff_section * 190 getSectionContaining(const COFFObjectFile &COFF, uint64_t VA) { 191 for (const auto &Section : COFF.sections()) { 192 uint64_t Address = Section.getAddress(); 193 uint64_t Size = Section.getSize(); 194 195 if (VA >= Address && (VA - Address) <= Size) 196 return COFF.getCOFFSection(Section); 197 } 198 return nullptr; 199 } 200 201 namespace llvm { 202 namespace Win64EH { 203 void Dumper::printRuntimeFunctionEntry(const Context &Ctx, 204 const coff_section *Section, 205 uint64_t Offset, 206 const RuntimeFunction &RF) { 207 SW.printString("StartAddress", 208 formatSymbol(Ctx, Section, Offset + 0, RF.StartAddress)); 209 SW.printString("EndAddress", 210 formatSymbol(Ctx, Section, Offset + 4, RF.EndAddress)); 211 SW.printString("UnwindInfoAddress", 212 formatSymbol(Ctx, Section, Offset + 8, RF.UnwindInfoOffset)); 213 } 214 215 // Prints one unwind code. Because an unwind code can occupy up to 3 slots in 216 // the unwind codes array, this function requires that the correct number of 217 // slots is provided. 218 void Dumper::printUnwindCode(const UnwindInfo& UI, ArrayRef<UnwindCode> UC) { 219 assert(UC.size() >= getNumUsedSlots(UC[0])); 220 221 SW.startLine() << format("0x%02X: ", unsigned(UC[0].u.CodeOffset)) 222 << getUnwindCodeTypeName(UC[0].getUnwindOp()); 223 224 switch (UC[0].getUnwindOp()) { 225 case UOP_PushNonVol: 226 OS << " reg=" << getUnwindRegisterName(UC[0].getOpInfo()); 227 break; 228 229 case UOP_AllocLarge: 230 OS << " size=" 231 << ((UC[0].getOpInfo() == 0) ? UC[1].FrameOffset * 8 232 : getLargeSlotValue(UC)); 233 break; 234 235 case UOP_AllocSmall: 236 OS << " size=" << (UC[0].getOpInfo() + 1) * 8; 237 break; 238 239 case UOP_SetFPReg: 240 if (UI.getFrameRegister() == 0) 241 OS << " reg=<invalid>"; 242 else 243 OS << " reg=" << getUnwindRegisterName(UI.getFrameRegister()) 244 << format(", offset=0x%X", UI.getFrameOffset() * 16); 245 break; 246 247 case UOP_SaveNonVol: 248 OS << " reg=" << getUnwindRegisterName(UC[0].getOpInfo()) 249 << format(", offset=0x%X", UC[1].FrameOffset * 8); 250 break; 251 252 case UOP_SaveNonVolBig: 253 OS << " reg=" << getUnwindRegisterName(UC[0].getOpInfo()) 254 << format(", offset=0x%X", getLargeSlotValue(UC)); 255 break; 256 257 case UOP_SaveXMM128: 258 OS << " reg=XMM" << static_cast<uint32_t>(UC[0].getOpInfo()) 259 << format(", offset=0x%X", UC[1].FrameOffset * 16); 260 break; 261 262 case UOP_SaveXMM128Big: 263 OS << " reg=XMM" << static_cast<uint32_t>(UC[0].getOpInfo()) 264 << format(", offset=0x%X", getLargeSlotValue(UC)); 265 break; 266 267 case UOP_PushMachFrame: 268 OS << " errcode=" << (UC[0].getOpInfo() == 0 ? "no" : "yes"); 269 break; 270 } 271 272 OS << "\n"; 273 } 274 275 void Dumper::printUnwindInfo(const Context &Ctx, const coff_section *Section, 276 off_t Offset, const UnwindInfo &UI) { 277 DictScope UIS(SW, "UnwindInfo"); 278 SW.printNumber("Version", UI.getVersion()); 279 SW.printFlags("Flags", UI.getFlags(), makeArrayRef(UnwindFlags)); 280 SW.printNumber("PrologSize", UI.PrologSize); 281 if (UI.getFrameRegister()) { 282 SW.printEnum("FrameRegister", UI.getFrameRegister(), 283 makeArrayRef(UnwindOpInfo)); 284 SW.printHex("FrameOffset", UI.getFrameOffset()); 285 } else { 286 SW.printString("FrameRegister", StringRef("-")); 287 SW.printString("FrameOffset", StringRef("-")); 288 } 289 290 SW.printNumber("UnwindCodeCount", UI.NumCodes); 291 { 292 ListScope UCS(SW, "UnwindCodes"); 293 ArrayRef<UnwindCode> UC(&UI.UnwindCodes[0], UI.NumCodes); 294 for (const UnwindCode *UCI = UC.begin(), *UCE = UC.end(); UCI < UCE; ++UCI) { 295 unsigned UsedSlots = getNumUsedSlots(*UCI); 296 if (UsedSlots > UC.size()) { 297 errs() << "corrupt unwind data"; 298 return; 299 } 300 301 printUnwindCode(UI, makeArrayRef(UCI, UCE)); 302 UCI = UCI + UsedSlots - 1; 303 } 304 } 305 306 uint64_t LSDAOffset = Offset + getOffsetOfLSDA(UI); 307 if (UI.getFlags() & (UNW_ExceptionHandler | UNW_TerminateHandler)) { 308 SW.printString("Handler", 309 formatSymbol(Ctx, Section, LSDAOffset, 310 UI.getLanguageSpecificHandlerOffset())); 311 } else if (UI.getFlags() & UNW_ChainInfo) { 312 if (const RuntimeFunction *Chained = UI.getChainedFunctionEntry()) { 313 DictScope CS(SW, "Chained"); 314 printRuntimeFunctionEntry(Ctx, Section, LSDAOffset, *Chained); 315 } 316 } 317 } 318 319 void Dumper::printRuntimeFunction(const Context &Ctx, 320 const coff_section *Section, 321 uint64_t SectionOffset, 322 const RuntimeFunction &RF) { 323 DictScope RFS(SW, "RuntimeFunction"); 324 printRuntimeFunctionEntry(Ctx, Section, SectionOffset, RF); 325 326 const coff_section *XData = nullptr; 327 uint64_t Offset; 328 resolveRelocation(Ctx, Section, SectionOffset + 8, XData, Offset); 329 Offset = Offset + RF.UnwindInfoOffset; 330 331 if (!XData) { 332 uint64_t Address = Ctx.COFF.getImageBase() + RF.UnwindInfoOffset; 333 XData = getSectionContaining(Ctx.COFF, Address); 334 if (!XData) 335 return; 336 Offset = RF.UnwindInfoOffset - XData->VirtualAddress; 337 } 338 339 ArrayRef<uint8_t> Contents; 340 if (Error E = Ctx.COFF.getSectionContents(XData, Contents)) 341 reportError(std::move(E), Ctx.COFF.getFileName()); 342 343 if (Contents.empty()) 344 return; 345 346 if (Offset > Contents.size()) 347 return; 348 349 const auto UI = reinterpret_cast<const UnwindInfo*>(Contents.data() + Offset); 350 printUnwindInfo(Ctx, XData, Offset, *UI); 351 } 352 353 void Dumper::printData(const Context &Ctx) { 354 for (const auto &Section : Ctx.COFF.sections()) { 355 StringRef Name; 356 if (Expected<StringRef> NameOrErr = Section.getName()) 357 Name = *NameOrErr; 358 else 359 consumeError(NameOrErr.takeError()); 360 361 if (Name != ".pdata" && !Name.startswith(".pdata$")) 362 continue; 363 364 const coff_section *PData = Ctx.COFF.getCOFFSection(Section); 365 ArrayRef<uint8_t> Contents; 366 367 if (Error E = Ctx.COFF.getSectionContents(PData, Contents)) 368 reportError(std::move(E), Ctx.COFF.getFileName()); 369 if (Contents.empty()) 370 continue; 371 372 const RuntimeFunction *Entries = 373 reinterpret_cast<const RuntimeFunction *>(Contents.data()); 374 const size_t Count = Contents.size() / sizeof(RuntimeFunction); 375 ArrayRef<RuntimeFunction> RuntimeFunctions(Entries, Count); 376 377 size_t Index = 0; 378 for (const auto &RF : RuntimeFunctions) { 379 printRuntimeFunction(Ctx, Ctx.COFF.getCOFFSection(Section), 380 Index * sizeof(RuntimeFunction), RF); 381 ++Index; 382 } 383 } 384 } 385 } 386 } 387 388