1 //===-- UnwindAssemblyInstEmulation.cpp --------------------------*- 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 "UnwindAssemblyInstEmulation.h" 11 12 #include "llvm-c/EnhancedDisassembly.h" 13 14 #include "lldb/Core/Address.h" 15 #include "lldb/Core/ArchSpec.h" 16 #include "lldb/Core/DataBufferHeap.h" 17 #include "lldb/Core/Disassembler.h" 18 #include "lldb/Core/Error.h" 19 #include "lldb/Core/Log.h" 20 #include "lldb/Core/PluginManager.h" 21 #include "lldb/Core/StreamString.h" 22 #include "lldb/Target/ExecutionContext.h" 23 #include "lldb/Target/Process.h" 24 #include "lldb/Target/Thread.h" 25 #include "lldb/Target/Target.h" 26 27 using namespace lldb; 28 using namespace lldb_private; 29 30 31 32 //----------------------------------------------------------------------------------------------- 33 // UnwindAssemblyParser_x86 method definitions 34 //----------------------------------------------------------------------------------------------- 35 36 bool 37 UnwindAssemblyInstEmulation::GetNonCallSiteUnwindPlanFromAssembly (AddressRange& range, 38 Thread& thread, 39 UnwindPlan& unwind_plan) 40 { 41 if (range.GetByteSize() > 0 && 42 range.GetBaseAddress().IsValid() && 43 m_inst_emulator_ap.get()) 44 { 45 46 // The the instruction emulation subclass setup the unwind plan for the 47 // first instruction. 48 m_inst_emulator_ap->CreateFunctionEntryUnwind (unwind_plan); 49 50 // CreateFunctionEntryUnwind should have created the first row. If it 51 // doesn't, then we are done. 52 if (unwind_plan.GetRowCount() == 0) 53 return false; 54 55 ExecutionContext exe_ctx; 56 thread.CalculateExecutionContext(exe_ctx); 57 DisassemblerSP disasm_sp (Disassembler::DisassembleRange (m_arch, 58 NULL, 59 exe_ctx, 60 range)); 61 62 LogSP log(GetLogIfAllCategoriesSet (LIBLLDB_LOG_UNWIND)); 63 64 if (disasm_sp) 65 { 66 67 m_range_ptr = ⦥ 68 m_thread_ptr = &thread; 69 m_unwind_plan_ptr = &unwind_plan; 70 71 const uint32_t addr_byte_size = m_arch.GetAddressByteSize(); 72 const bool show_address = true; 73 const bool show_bytes = true; 74 const bool raw = false; 75 // Initialize the CFA with a known value. In the 32 bit case 76 // it will be 0x80000000, and in the 64 bit case 0x8000000000000000. 77 // We use the address byte size to be safe for any future addresss sizes 78 m_inst_emulator_ap->GetRegisterInfo (unwind_plan.GetRegisterKind(), 79 unwind_plan.GetInitialCFARegister(), 80 m_cfa_reg_info); 81 82 m_fp_is_cfa = false; 83 m_register_values.clear(); 84 m_pushed_regs.clear(); 85 86 m_initial_sp = (1ull << ((addr_byte_size * 8) - 1)); 87 RegisterValue cfa_reg_value; 88 cfa_reg_value.SetUInt (m_initial_sp, m_cfa_reg_info.byte_size); 89 SetRegisterValue (m_cfa_reg_info, cfa_reg_value); 90 91 const InstructionList &inst_list = disasm_sp->GetInstructionList (); 92 const size_t num_instructions = inst_list.GetSize(); 93 if (num_instructions > 0) 94 { 95 Instruction *inst = inst_list.GetInstructionAtIndex (0).get(); 96 const addr_t base_addr = inst->GetAddress().GetFileAddress(); 97 // Initialize the current row with the one row that was created 98 // from the CreateFunctionEntryUnwind call above... 99 m_curr_row = unwind_plan.GetLastRow(); 100 101 for (size_t idx=0; idx<num_instructions; ++idx) 102 { 103 inst = inst_list.GetInstructionAtIndex (idx).get(); 104 if (inst) 105 { 106 107 if (log && log->GetVerbose ()) 108 { 109 StreamString strm; 110 inst->Dump(&strm, inst_list.GetMaxOpcocdeByteSize (), show_address, show_bytes, &exe_ctx, raw); 111 log->PutCString (strm.GetData()); 112 } 113 114 m_inst_emulator_ap->SetInstruction (inst->GetOpcode(), 115 inst->GetAddress(), 116 exe_ctx.GetTargetPtr()); 117 118 m_inst_emulator_ap->EvaluateInstruction (eEmulateInstructionOptionIgnoreConditions); 119 120 if (unwind_plan.GetLastRow() != m_curr_row) 121 { 122 // Be sure to not edit the offset unless our row has changed 123 // so that the "!=" call above doesn't trigger every time 124 m_curr_row.SetOffset (inst->GetAddress().GetFileAddress() + inst->GetOpcode().GetByteSize() - base_addr); 125 // Append the new row 126 unwind_plan.AppendRow (m_curr_row); 127 } 128 } 129 } 130 } 131 } 132 133 if (log && log->GetVerbose ()) 134 { 135 StreamString strm; 136 lldb::addr_t base_addr = range.GetBaseAddress().GetLoadAddress(thread.CalculateTarget().get()); 137 strm.Printf ("Resulting unwind rows for [0x%llx - 0x%llx):", base_addr, base_addr + range.GetByteSize()); 138 unwind_plan.Dump(strm, &thread, base_addr); 139 log->PutCString (strm.GetData()); 140 } 141 return unwind_plan.GetRowCount() > 0; 142 } 143 return false; 144 } 145 146 bool 147 UnwindAssemblyInstEmulation::GetFastUnwindPlan (AddressRange& func, 148 Thread& thread, 149 UnwindPlan &unwind_plan) 150 { 151 return false; 152 } 153 154 bool 155 UnwindAssemblyInstEmulation::FirstNonPrologueInsn (AddressRange& func, 156 const ExecutionContext &exe_ctx, 157 Address& first_non_prologue_insn) 158 { 159 return false; 160 } 161 162 UnwindAssembly * 163 UnwindAssemblyInstEmulation::CreateInstance (const ArchSpec &arch) 164 { 165 std::auto_ptr<EmulateInstruction> inst_emulator_ap (EmulateInstruction::FindPlugin (arch, eInstructionTypePrologueEpilogue, NULL)); 166 // Make sure that all prologue instructions are handled 167 if (inst_emulator_ap.get()) 168 return new UnwindAssemblyInstEmulation (arch, inst_emulator_ap.release()); 169 return NULL; 170 } 171 172 173 //------------------------------------------------------------------ 174 // PluginInterface protocol in UnwindAssemblyParser_x86 175 //------------------------------------------------------------------ 176 177 const char * 178 UnwindAssemblyInstEmulation::GetPluginName() 179 { 180 return "UnwindAssemblyInstEmulation"; 181 } 182 183 const char * 184 UnwindAssemblyInstEmulation::GetShortPluginName() 185 { 186 return "unwindassembly.inst-emulation"; 187 } 188 189 190 uint32_t 191 UnwindAssemblyInstEmulation::GetPluginVersion() 192 { 193 return 1; 194 } 195 196 void 197 UnwindAssemblyInstEmulation::Initialize() 198 { 199 PluginManager::RegisterPlugin (GetPluginNameStatic(), 200 GetPluginDescriptionStatic(), 201 CreateInstance); 202 } 203 204 void 205 UnwindAssemblyInstEmulation::Terminate() 206 { 207 PluginManager::UnregisterPlugin (CreateInstance); 208 } 209 210 211 const char * 212 UnwindAssemblyInstEmulation::GetPluginNameStatic() 213 { 214 return "UnwindAssemblyInstEmulation"; 215 } 216 217 const char * 218 UnwindAssemblyInstEmulation::GetPluginDescriptionStatic() 219 { 220 return "Instruction emulation based unwind information."; 221 } 222 223 224 uint64_t 225 UnwindAssemblyInstEmulation::MakeRegisterKindValuePair (const RegisterInfo ®_info) 226 { 227 uint32_t reg_kind, reg_num; 228 if (EmulateInstruction::GetBestRegisterKindAndNumber (®_info, reg_kind, reg_num)) 229 return (uint64_t)reg_kind << 24 | reg_num; 230 return 0ull; 231 } 232 233 void 234 UnwindAssemblyInstEmulation::SetRegisterValue (const RegisterInfo ®_info, const RegisterValue ®_value) 235 { 236 m_register_values[MakeRegisterKindValuePair (reg_info)] = reg_value; 237 } 238 239 bool 240 UnwindAssemblyInstEmulation::GetRegisterValue (const RegisterInfo ®_info, RegisterValue ®_value) 241 { 242 const uint64_t reg_id = MakeRegisterKindValuePair (reg_info); 243 RegisterValueMap::const_iterator pos = m_register_values.find(reg_id); 244 if (pos != m_register_values.end()) 245 { 246 reg_value = pos->second; 247 return true; // We had a real value that comes from an opcode that wrote 248 // to it... 249 } 250 // We are making up a value that is recognizable... 251 reg_value.SetUInt(reg_id, reg_info.byte_size); 252 return false; 253 } 254 255 256 size_t 257 UnwindAssemblyInstEmulation::ReadMemory (EmulateInstruction *instruction, 258 void *baton, 259 const EmulateInstruction::Context &context, 260 lldb::addr_t addr, 261 void *dst, 262 size_t dst_len) 263 { 264 LogSP log(GetLogIfAllCategoriesSet (LIBLLDB_LOG_UNWIND)); 265 266 if (log && log->GetVerbose ()) 267 { 268 StreamString strm; 269 strm.Printf ("UnwindAssemblyInstEmulation::ReadMemory (addr = 0x%16.16llx, dst = %p, dst_len = %zu, context = ", 270 addr, 271 dst, 272 dst_len); 273 context.Dump(strm, instruction); 274 log->PutCString (strm.GetData ()); 275 } 276 return dst_len; 277 } 278 279 size_t 280 UnwindAssemblyInstEmulation::WriteMemory (EmulateInstruction *instruction, 281 void *baton, 282 const EmulateInstruction::Context &context, 283 lldb::addr_t addr, 284 const void *dst, 285 size_t dst_len) 286 { 287 if (baton && dst && dst_len) 288 return ((UnwindAssemblyInstEmulation *)baton)->WriteMemory (instruction, context, addr, dst, dst_len); 289 return 0; 290 } 291 292 size_t 293 UnwindAssemblyInstEmulation::WriteMemory (EmulateInstruction *instruction, 294 const EmulateInstruction::Context &context, 295 lldb::addr_t addr, 296 const void *dst, 297 size_t dst_len) 298 { 299 DataExtractor data (dst, 300 dst_len, 301 instruction->GetArchitecture ().GetByteOrder(), 302 instruction->GetArchitecture ().GetAddressByteSize()); 303 304 LogSP log(GetLogIfAllCategoriesSet (LIBLLDB_LOG_UNWIND)); 305 306 if (log && log->GetVerbose ()) 307 { 308 StreamString strm; 309 310 strm.PutCString ("UnwindAssemblyInstEmulation::WriteMemory ("); 311 data.Dump(&strm, 0, eFormatBytes, 1, dst_len, UINT32_MAX, addr, 0, 0); 312 strm.PutCString (", context = "); 313 context.Dump(strm, instruction); 314 log->PutCString (strm.GetData()); 315 } 316 317 const bool can_replace = true; 318 const bool cant_replace = false; 319 320 switch (context.type) 321 { 322 default: 323 case EmulateInstruction::eContextInvalid: 324 case EmulateInstruction::eContextReadOpcode: 325 case EmulateInstruction::eContextImmediate: 326 case EmulateInstruction::eContextAdjustBaseRegister: 327 case EmulateInstruction::eContextRegisterPlusOffset: 328 case EmulateInstruction::eContextAdjustPC: 329 case EmulateInstruction::eContextRegisterStore: 330 case EmulateInstruction::eContextRegisterLoad: 331 case EmulateInstruction::eContextRelativeBranchImmediate: 332 case EmulateInstruction::eContextAbsoluteBranchRegister: 333 case EmulateInstruction::eContextSupervisorCall: 334 case EmulateInstruction::eContextTableBranchReadMemory: 335 case EmulateInstruction::eContextWriteRegisterRandomBits: 336 case EmulateInstruction::eContextWriteMemoryRandomBits: 337 case EmulateInstruction::eContextArithmetic: 338 case EmulateInstruction::eContextAdvancePC: 339 case EmulateInstruction::eContextReturnFromException: 340 case EmulateInstruction::eContextPopRegisterOffStack: 341 case EmulateInstruction::eContextAdjustStackPointer: 342 break; 343 344 case EmulateInstruction::eContextPushRegisterOnStack: 345 { 346 uint32_t reg_num = LLDB_INVALID_REGNUM; 347 bool is_return_address_reg = false; 348 const uint32_t unwind_reg_kind = m_unwind_plan_ptr->GetRegisterKind(); 349 if (context.info_type == EmulateInstruction::eInfoTypeRegisterToRegisterPlusOffset) 350 { 351 reg_num = context.info.RegisterToRegisterPlusOffset.data_reg.kinds[unwind_reg_kind]; 352 if (context.info.RegisterToRegisterPlusOffset.data_reg.kinds[eRegisterKindGeneric] == LLDB_REGNUM_GENERIC_RA) 353 is_return_address_reg = true; 354 } 355 else 356 { 357 assert (!"unhandled case, add code to handle this!"); 358 } 359 360 if (reg_num != LLDB_INVALID_REGNUM) 361 { 362 if (m_pushed_regs.find (reg_num) == m_pushed_regs.end()) 363 { 364 m_pushed_regs[reg_num] = addr; 365 const int32_t offset = addr - m_initial_sp; 366 m_curr_row.SetRegisterLocationToAtCFAPlusOffset (reg_num, offset, cant_replace); 367 if (is_return_address_reg) 368 { 369 // This push was pushing the return address register, 370 // so this is also how we will unwind the PC... 371 RegisterInfo pc_reg_info; 372 if (instruction->GetRegisterInfo (eRegisterKindGeneric, LLDB_REGNUM_GENERIC_PC, pc_reg_info)) 373 { 374 uint32_t pc_reg_num = pc_reg_info.kinds[unwind_reg_kind]; 375 if (pc_reg_num != LLDB_INVALID_REGNUM) 376 m_curr_row.SetRegisterLocationToAtCFAPlusOffset (pc_reg_num, offset, can_replace); 377 } 378 } 379 } 380 } 381 } 382 break; 383 384 } 385 386 return dst_len; 387 } 388 389 bool 390 UnwindAssemblyInstEmulation::ReadRegister (EmulateInstruction *instruction, 391 void *baton, 392 const RegisterInfo *reg_info, 393 RegisterValue ®_value) 394 { 395 396 if (baton && reg_info) 397 return ((UnwindAssemblyInstEmulation *)baton)->ReadRegister (instruction, reg_info, reg_value); 398 return false; 399 } 400 bool 401 UnwindAssemblyInstEmulation::ReadRegister (EmulateInstruction *instruction, 402 const RegisterInfo *reg_info, 403 RegisterValue ®_value) 404 { 405 bool synthetic = GetRegisterValue (*reg_info, reg_value); 406 407 LogSP log(GetLogIfAllCategoriesSet (LIBLLDB_LOG_UNWIND)); 408 409 if (log && log->GetVerbose ()) 410 { 411 412 StreamString strm; 413 strm.Printf ("UnwindAssemblyInstEmulation::ReadRegister (name = \"%s\") => synthetic_value = %i, value = ", reg_info->name, synthetic); 414 reg_value.Dump(&strm, reg_info, false, false, eFormatDefault); 415 log->PutCString(strm.GetData()); 416 } 417 return true; 418 } 419 420 bool 421 UnwindAssemblyInstEmulation::WriteRegister (EmulateInstruction *instruction, 422 void *baton, 423 const EmulateInstruction::Context &context, 424 const RegisterInfo *reg_info, 425 const RegisterValue ®_value) 426 { 427 if (baton && reg_info) 428 return ((UnwindAssemblyInstEmulation *)baton)->WriteRegister (instruction, context, reg_info, reg_value); 429 return false; 430 } 431 bool 432 UnwindAssemblyInstEmulation::WriteRegister (EmulateInstruction *instruction, 433 const EmulateInstruction::Context &context, 434 const RegisterInfo *reg_info, 435 const RegisterValue ®_value) 436 { 437 LogSP log(GetLogIfAllCategoriesSet (LIBLLDB_LOG_UNWIND)); 438 439 if (log && log->GetVerbose ()) 440 { 441 442 StreamString strm; 443 strm.Printf ("UnwindAssemblyInstEmulation::WriteRegister (name = \"%s\", value = ", reg_info->name); 444 reg_value.Dump(&strm, reg_info, false, false, eFormatDefault); 445 strm.PutCString (", context = "); 446 context.Dump(strm, instruction); 447 log->PutCString(strm.GetData()); 448 } 449 450 const bool must_replace = true; 451 SetRegisterValue (*reg_info, reg_value); 452 453 switch (context.type) 454 { 455 default: 456 case EmulateInstruction::eContextInvalid: 457 case EmulateInstruction::eContextReadOpcode: 458 case EmulateInstruction::eContextImmediate: 459 case EmulateInstruction::eContextAdjustBaseRegister: 460 case EmulateInstruction::eContextRegisterPlusOffset: 461 case EmulateInstruction::eContextAdjustPC: 462 case EmulateInstruction::eContextRegisterStore: 463 case EmulateInstruction::eContextRegisterLoad: 464 case EmulateInstruction::eContextRelativeBranchImmediate: 465 case EmulateInstruction::eContextAbsoluteBranchRegister: 466 case EmulateInstruction::eContextSupervisorCall: 467 case EmulateInstruction::eContextTableBranchReadMemory: 468 case EmulateInstruction::eContextWriteRegisterRandomBits: 469 case EmulateInstruction::eContextWriteMemoryRandomBits: 470 case EmulateInstruction::eContextArithmetic: 471 case EmulateInstruction::eContextAdvancePC: 472 case EmulateInstruction::eContextReturnFromException: 473 case EmulateInstruction::eContextPushRegisterOnStack: 474 // { 475 // const uint32_t reg_num = reg_info->kinds[m_unwind_plan_ptr->GetRegisterKind()]; 476 // if (reg_num != LLDB_INVALID_REGNUM) 477 // { 478 // const bool can_replace_only_if_unspecified = true; 479 // 480 // m_curr_row.SetRegisterLocationToUndefined (reg_num, 481 // can_replace_only_if_unspecified, 482 // can_replace_only_if_unspecified); 483 // } 484 // } 485 break; 486 487 case EmulateInstruction::eContextPopRegisterOffStack: 488 { 489 const uint32_t reg_num = reg_info->kinds[m_unwind_plan_ptr->GetRegisterKind()]; 490 if (reg_num != LLDB_INVALID_REGNUM) 491 { 492 m_curr_row.SetRegisterLocationToSame (reg_num, must_replace); 493 } 494 } 495 break; 496 497 case EmulateInstruction::eContextSetFramePointer: 498 if (!m_fp_is_cfa) 499 { 500 m_fp_is_cfa = true; 501 m_cfa_reg_info = *reg_info; 502 const uint32_t cfa_reg_num = reg_info->kinds[m_unwind_plan_ptr->GetRegisterKind()]; 503 assert (cfa_reg_num != LLDB_INVALID_REGNUM); 504 m_curr_row.SetCFARegister(cfa_reg_num); 505 m_curr_row.SetCFAOffset(m_initial_sp - reg_value.GetAsUInt64()); 506 } 507 break; 508 509 case EmulateInstruction::eContextAdjustStackPointer: 510 // If we have created a frame using the frame pointer, don't follow 511 // subsequent adjustments to the stack pointer. 512 if (!m_fp_is_cfa) 513 { 514 m_curr_row.SetCFAOffset (m_initial_sp - reg_value.GetAsUInt64()); 515 } 516 break; 517 } 518 return true; 519 } 520 521 522