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::string formatSymbol(const Dumper::Context &Ctx, 115 const coff_section *Section, uint64_t Offset, 116 uint32_t Displacement) { 117 std::string Buffer; 118 raw_string_ostream OS(Buffer); 119 120 SymbolRef Symbol; 121 if (!Ctx.ResolveSymbol(Section, Offset, Symbol, Ctx.UserData)) { 122 Expected<StringRef> Name = Symbol.getName(); 123 if (Name) { 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 } else { 131 // TODO: Actually report errors helpfully. 132 consumeError(Name.takeError()); 133 } 134 } 135 136 OS << format(" (0x%" PRIX64 ")", Offset); 137 return OS.str(); 138 } 139 140 static std::error_code resolveRelocation(const Dumper::Context &Ctx, 141 const coff_section *Section, 142 uint64_t Offset, 143 const coff_section *&ResolvedSection, 144 uint64_t &ResolvedAddress) { 145 SymbolRef Symbol; 146 if (std::error_code EC = 147 Ctx.ResolveSymbol(Section, Offset, Symbol, Ctx.UserData)) 148 return EC; 149 150 Expected<uint64_t> ResolvedAddressOrErr = Symbol.getAddress(); 151 if (!ResolvedAddressOrErr) 152 return errorToErrorCode(ResolvedAddressOrErr.takeError()); 153 ResolvedAddress = *ResolvedAddressOrErr; 154 155 Expected<section_iterator> SI = Symbol.getSection(); 156 if (!SI) 157 return errorToErrorCode(SI.takeError()); 158 ResolvedSection = Ctx.COFF.getCOFFSection(**SI); 159 return std::error_code(); 160 } 161 162 namespace llvm { 163 namespace Win64EH { 164 void Dumper::printRuntimeFunctionEntry(const Context &Ctx, 165 const coff_section *Section, 166 uint64_t Offset, 167 const RuntimeFunction &RF) { 168 SW.printString("StartAddress", 169 formatSymbol(Ctx, Section, Offset + 0, RF.StartAddress)); 170 SW.printString("EndAddress", 171 formatSymbol(Ctx, Section, Offset + 4, RF.EndAddress)); 172 SW.printString("UnwindInfoAddress", 173 formatSymbol(Ctx, Section, Offset + 8, RF.UnwindInfoOffset)); 174 } 175 176 // Prints one unwind code. Because an unwind code can occupy up to 3 slots in 177 // the unwind codes array, this function requires that the correct number of 178 // slots is provided. 179 void Dumper::printUnwindCode(const UnwindInfo& UI, ArrayRef<UnwindCode> UC) { 180 assert(UC.size() >= getNumUsedSlots(UC[0])); 181 182 SW.startLine() << format("0x%02X: ", unsigned(UC[0].u.CodeOffset)) 183 << getUnwindCodeTypeName(UC[0].getUnwindOp()); 184 185 switch (UC[0].getUnwindOp()) { 186 case UOP_PushNonVol: 187 OS << " reg=" << getUnwindRegisterName(UC[0].getOpInfo()); 188 break; 189 190 case UOP_AllocLarge: 191 OS << " size=" 192 << ((UC[0].getOpInfo() == 0) ? UC[1].FrameOffset * 8 193 : getLargeSlotValue(UC)); 194 break; 195 196 case UOP_AllocSmall: 197 OS << " size=" << (UC[0].getOpInfo() + 1) * 8; 198 break; 199 200 case UOP_SetFPReg: 201 if (UI.getFrameRegister() == 0) 202 OS << " reg=<invalid>"; 203 else 204 OS << " reg=" << getUnwindRegisterName(UI.getFrameRegister()) 205 << format(", offset=0x%X", UI.getFrameOffset() * 16); 206 break; 207 208 case UOP_SaveNonVol: 209 OS << " reg=" << getUnwindRegisterName(UC[0].getOpInfo()) 210 << format(", offset=0x%X", UC[1].FrameOffset * 8); 211 break; 212 213 case UOP_SaveNonVolBig: 214 OS << " reg=" << getUnwindRegisterName(UC[0].getOpInfo()) 215 << format(", offset=0x%X", getLargeSlotValue(UC)); 216 break; 217 218 case UOP_SaveXMM128: 219 OS << " reg=XMM" << static_cast<uint32_t>(UC[0].getOpInfo()) 220 << format(", offset=0x%X", UC[1].FrameOffset * 16); 221 break; 222 223 case UOP_SaveXMM128Big: 224 OS << " reg=XMM" << static_cast<uint32_t>(UC[0].getOpInfo()) 225 << format(", offset=0x%X", getLargeSlotValue(UC)); 226 break; 227 228 case UOP_PushMachFrame: 229 OS << " errcode=" << (UC[0].getOpInfo() == 0 ? "no" : "yes"); 230 break; 231 } 232 233 OS << "\n"; 234 } 235 236 void Dumper::printUnwindInfo(const Context &Ctx, const coff_section *Section, 237 off_t Offset, const UnwindInfo &UI) { 238 DictScope UIS(SW, "UnwindInfo"); 239 SW.printNumber("Version", UI.getVersion()); 240 SW.printFlags("Flags", UI.getFlags(), makeArrayRef(UnwindFlags)); 241 SW.printNumber("PrologSize", UI.PrologSize); 242 if (UI.getFrameRegister()) { 243 SW.printEnum("FrameRegister", UI.getFrameRegister(), 244 makeArrayRef(UnwindOpInfo)); 245 SW.printHex("FrameOffset", UI.getFrameOffset()); 246 } else { 247 SW.printString("FrameRegister", StringRef("-")); 248 SW.printString("FrameOffset", StringRef("-")); 249 } 250 251 SW.printNumber("UnwindCodeCount", UI.NumCodes); 252 { 253 ListScope UCS(SW, "UnwindCodes"); 254 ArrayRef<UnwindCode> UC(&UI.UnwindCodes[0], UI.NumCodes); 255 for (const UnwindCode *UCI = UC.begin(), *UCE = UC.end(); UCI < UCE; ++UCI) { 256 unsigned UsedSlots = getNumUsedSlots(*UCI); 257 if (UsedSlots > UC.size()) { 258 errs() << "corrupt unwind data"; 259 return; 260 } 261 262 printUnwindCode(UI, makeArrayRef(UCI, UCE)); 263 UCI = UCI + UsedSlots - 1; 264 } 265 } 266 267 uint64_t LSDAOffset = Offset + getOffsetOfLSDA(UI); 268 if (UI.getFlags() & (UNW_ExceptionHandler | UNW_TerminateHandler)) { 269 SW.printString("Handler", 270 formatSymbol(Ctx, Section, LSDAOffset, 271 UI.getLanguageSpecificHandlerOffset())); 272 } else if (UI.getFlags() & UNW_ChainInfo) { 273 if (const RuntimeFunction *Chained = UI.getChainedFunctionEntry()) { 274 DictScope CS(SW, "Chained"); 275 printRuntimeFunctionEntry(Ctx, Section, LSDAOffset, *Chained); 276 } 277 } 278 } 279 280 void Dumper::printRuntimeFunction(const Context &Ctx, 281 const coff_section *Section, 282 uint64_t SectionOffset, 283 const RuntimeFunction &RF) { 284 DictScope RFS(SW, "RuntimeFunction"); 285 printRuntimeFunctionEntry(Ctx, Section, SectionOffset, RF); 286 287 const coff_section *XData; 288 uint64_t Offset; 289 resolveRelocation(Ctx, Section, SectionOffset + 8, XData, Offset); 290 291 ArrayRef<uint8_t> Contents; 292 error(Ctx.COFF.getSectionContents(XData, Contents)); 293 if (Contents.empty()) 294 return; 295 296 Offset = Offset + RF.UnwindInfoOffset; 297 if (Offset > Contents.size()) 298 return; 299 300 const auto UI = reinterpret_cast<const UnwindInfo*>(Contents.data() + Offset); 301 printUnwindInfo(Ctx, XData, Offset, *UI); 302 } 303 304 void Dumper::printData(const Context &Ctx) { 305 for (const auto &Section : Ctx.COFF.sections()) { 306 StringRef Name; 307 Section.getName(Name); 308 309 if (Name != ".pdata" && !Name.startswith(".pdata$")) 310 continue; 311 312 const coff_section *PData = Ctx.COFF.getCOFFSection(Section); 313 ArrayRef<uint8_t> Contents; 314 error(Ctx.COFF.getSectionContents(PData, Contents)); 315 if (Contents.empty()) 316 continue; 317 318 const RuntimeFunction *Entries = 319 reinterpret_cast<const RuntimeFunction *>(Contents.data()); 320 const size_t Count = Contents.size() / sizeof(RuntimeFunction); 321 ArrayRef<RuntimeFunction> RuntimeFunctions(Entries, Count); 322 323 size_t Index = 0; 324 for (const auto &RF : RuntimeFunctions) { 325 printRuntimeFunction(Ctx, Ctx.COFF.getCOFFSection(Section), 326 Index * sizeof(RuntimeFunction), RF); 327 ++Index; 328 } 329 } 330 } 331 } 332 } 333 334