| File: | tools/lldb/source/Plugins/Process/Utility/RegisterContextLLDB.cpp |
| Location: | line 1727, column 17 |
| Description: | Value stored to 'cfa_reg_contents' is never read |
| 1 | //===-- RegisterContextLLDB.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 | |
| 11 | #include "lldb/lldb-private.h" |
| 12 | #include "lldb/Core/Address.h" |
| 13 | #include "lldb/Core/AddressRange.h" |
| 14 | #include "lldb/Core/DataBufferHeap.h" |
| 15 | #include "lldb/Core/Log.h" |
| 16 | #include "lldb/Core/Module.h" |
| 17 | #include "lldb/Core/RegisterValue.h" |
| 18 | #include "lldb/Core/Value.h" |
| 19 | #include "lldb/Expression/DWARFExpression.h" |
| 20 | #include "lldb/Symbol/DWARFCallFrameInfo.h" |
| 21 | #include "lldb/Symbol/FuncUnwinders.h" |
| 22 | #include "lldb/Symbol/Function.h" |
| 23 | #include "lldb/Symbol/ObjectFile.h" |
| 24 | #include "lldb/Symbol/Symbol.h" |
| 25 | #include "lldb/Symbol/SymbolContext.h" |
| 26 | #include "lldb/Target/ABI.h" |
| 27 | #include "lldb/Target/DynamicLoader.h" |
| 28 | #include "lldb/Target/ExecutionContext.h" |
| 29 | #include "lldb/Target/Platform.h" |
| 30 | #include "lldb/Target/Process.h" |
| 31 | #include "lldb/Target/SectionLoadList.h" |
| 32 | #include "lldb/Target/StackFrame.h" |
| 33 | #include "lldb/Target/Target.h" |
| 34 | #include "lldb/Target/Thread.h" |
| 35 | |
| 36 | #include "RegisterContextLLDB.h" |
| 37 | |
| 38 | using namespace lldb; |
| 39 | using namespace lldb_private; |
| 40 | |
| 41 | RegisterContextLLDB::RegisterContextLLDB |
| 42 | ( |
| 43 | Thread& thread, |
| 44 | const SharedPtr &next_frame, |
| 45 | SymbolContext& sym_ctx, |
| 46 | uint32_t frame_number, |
| 47 | UnwindLLDB& unwind_lldb |
| 48 | ) : |
| 49 | RegisterContext (thread, frame_number), |
| 50 | m_thread(thread), |
| 51 | m_fast_unwind_plan_sp (), |
| 52 | m_full_unwind_plan_sp (), |
| 53 | m_fallback_unwind_plan_sp (), |
| 54 | m_all_registers_available(false), |
| 55 | m_frame_type (-1), |
| 56 | m_cfa (LLDB_INVALID_ADDRESS(18446744073709551615UL)), |
| 57 | m_start_pc (), |
| 58 | m_current_pc (), |
| 59 | m_current_offset (0), |
| 60 | m_current_offset_backed_up_one (0), |
| 61 | m_sym_ctx(sym_ctx), |
| 62 | m_sym_ctx_valid (false), |
| 63 | m_frame_number (frame_number), |
| 64 | m_registers(), |
| 65 | m_parent_unwind (unwind_lldb) |
| 66 | { |
| 67 | m_sym_ctx.Clear(false); |
| 68 | m_sym_ctx_valid = false; |
| 69 | |
| 70 | if (IsFrameZero ()) |
| 71 | { |
| 72 | InitializeZerothFrame (); |
| 73 | } |
| 74 | else |
| 75 | { |
| 76 | InitializeNonZerothFrame (); |
| 77 | } |
| 78 | |
| 79 | // This same code exists over in the GetFullUnwindPlanForFrame() but it may not have been executed yet |
| 80 | if (IsFrameZero() |
| 81 | || next_frame->m_frame_type == eTrapHandlerFrame |
| 82 | || next_frame->m_frame_type == eDebuggerFrame) |
| 83 | { |
| 84 | m_all_registers_available = true; |
| 85 | } |
| 86 | } |
| 87 | |
| 88 | bool |
| 89 | RegisterContextLLDB::IsUnwindPlanValidForCurrentPC(lldb::UnwindPlanSP unwind_plan_sp, int &valid_pc_offset) |
| 90 | { |
| 91 | if (!unwind_plan_sp) |
| 92 | return false; |
| 93 | |
| 94 | // check if m_current_pc is valid |
| 95 | if (unwind_plan_sp->PlanValidAtAddress(m_current_pc)) |
| 96 | { |
| 97 | // yes - current offset can be used as is |
| 98 | valid_pc_offset = m_current_offset; |
| 99 | return true; |
| 100 | } |
| 101 | |
| 102 | // if m_current_offset <= 0, we've got nothing else to try |
| 103 | if (m_current_offset <= 0) |
| 104 | return false; |
| 105 | |
| 106 | // check pc - 1 to see if it's valid |
| 107 | Address pc_minus_one (m_current_pc); |
| 108 | pc_minus_one.SetOffset(m_current_pc.GetOffset() - 1); |
| 109 | if (unwind_plan_sp->PlanValidAtAddress(pc_minus_one)) |
| 110 | { |
| 111 | // *valid_pc_offset = m_current_offset - 1; |
| 112 | valid_pc_offset = m_current_pc.GetOffset() - 1; |
| 113 | return true; |
| 114 | } |
| 115 | |
| 116 | return false; |
| 117 | } |
| 118 | |
| 119 | // Initialize a RegisterContextLLDB which is the first frame of a stack -- the zeroth frame or currently |
| 120 | // executing frame. |
| 121 | |
| 122 | void |
| 123 | RegisterContextLLDB::InitializeZerothFrame() |
| 124 | { |
| 125 | Log *log(GetLogIfAllCategoriesSet (LIBLLDB_LOG_UNWIND(1u << 15))); |
| 126 | ExecutionContext exe_ctx(m_thread.shared_from_this()); |
| 127 | RegisterContextSP reg_ctx_sp = m_thread.GetRegisterContext(); |
| 128 | |
| 129 | if (reg_ctx_sp.get() == NULL__null) |
| 130 | { |
| 131 | m_frame_type = eNotAValidFrame; |
| 132 | UnwindLogMsg ("frame does not have a register context"); |
| 133 | return; |
| 134 | } |
| 135 | |
| 136 | addr_t current_pc = reg_ctx_sp->GetPC(); |
| 137 | |
| 138 | if (current_pc == LLDB_INVALID_ADDRESS(18446744073709551615UL)) |
| 139 | { |
| 140 | m_frame_type = eNotAValidFrame; |
| 141 | UnwindLogMsg ("frame does not have a pc"); |
| 142 | return; |
| 143 | } |
| 144 | |
| 145 | Process *process = exe_ctx.GetProcessPtr(); |
| 146 | |
| 147 | // Let ABIs fixup code addresses to make sure they are valid. In ARM ABIs |
| 148 | // this will strip bit zero in case we read a PC from memory or from the LR. |
| 149 | // (which would be a no-op in frame 0 where we get it from the register set, |
| 150 | // but still a good idea to make the call here for other ABIs that may exist.) |
| 151 | ABI *abi = process->GetABI().get(); |
| 152 | if (abi) |
| 153 | current_pc = abi->FixCodeAddress(current_pc); |
| 154 | |
| 155 | // Initialize m_current_pc, an Address object, based on current_pc, an addr_t. |
| 156 | m_current_pc.SetLoadAddress (current_pc, &process->GetTarget()); |
| 157 | |
| 158 | // If we don't have a Module for some reason, we're not going to find symbol/function information - just |
| 159 | // stick in some reasonable defaults and hope we can unwind past this frame. |
| 160 | ModuleSP pc_module_sp (m_current_pc.GetModule()); |
| 161 | if (!m_current_pc.IsValid() || !pc_module_sp) |
| 162 | { |
| 163 | UnwindLogMsg ("using architectural default unwind method"); |
| 164 | } |
| 165 | |
| 166 | // We require either a symbol or function in the symbols context to be successfully |
| 167 | // filled in or this context is of no use to us. |
| 168 | const uint32_t resolve_scope = eSymbolContextFunction | eSymbolContextSymbol; |
| 169 | if (pc_module_sp.get() |
| 170 | && (pc_module_sp->ResolveSymbolContextForAddress (m_current_pc, resolve_scope, m_sym_ctx) & resolve_scope)) |
| 171 | { |
| 172 | m_sym_ctx_valid = true; |
| 173 | } |
| 174 | |
| 175 | if (m_sym_ctx.symbol) |
| 176 | { |
| 177 | UnwindLogMsg ("with pc value of 0x%" PRIx64"l" "x" ", symbol name is '%s'", |
| 178 | current_pc, m_sym_ctx.symbol == NULL__null ? "" : m_sym_ctx.symbol->GetName().AsCString()); |
| 179 | } |
| 180 | else if (m_sym_ctx.function) |
| 181 | { |
| 182 | UnwindLogMsg ("with pc value of 0x%" PRIx64"l" "x" ", function name is '%s'", |
| 183 | current_pc, m_sym_ctx.symbol == NULL__null ? "" : m_sym_ctx.function->GetName().AsCString()); |
| 184 | } |
| 185 | else |
| 186 | { |
| 187 | UnwindLogMsg ("with pc value of 0x%" PRIx64"l" "x" ", no symbol/function name is known.", current_pc); |
| 188 | } |
| 189 | |
| 190 | AddressRange addr_range; |
| 191 | m_sym_ctx.GetAddressRange (resolve_scope, 0, false, addr_range); |
| 192 | |
| 193 | if (IsTrapHandlerSymbol (process, m_sym_ctx)) |
| 194 | { |
| 195 | m_frame_type = eTrapHandlerFrame; |
| 196 | } |
| 197 | else |
| 198 | { |
| 199 | // FIXME: Detect eDebuggerFrame here. |
| 200 | m_frame_type = eNormalFrame; |
| 201 | } |
| 202 | |
| 203 | // If we were able to find a symbol/function, set addr_range to the bounds of that symbol/function. |
| 204 | // else treat the current pc value as the start_pc and record no offset. |
| 205 | if (addr_range.GetBaseAddress().IsValid()) |
| 206 | { |
| 207 | m_start_pc = addr_range.GetBaseAddress(); |
| 208 | if (m_current_pc.GetSection() == m_start_pc.GetSection()) |
| 209 | { |
| 210 | m_current_offset = m_current_pc.GetOffset() - m_start_pc.GetOffset(); |
| 211 | } |
| 212 | else if (m_current_pc.GetModule() == m_start_pc.GetModule()) |
| 213 | { |
| 214 | // This means that whatever symbol we kicked up isn't really correct |
| 215 | // --- we should not cross section boundaries ... We really should NULL out |
| 216 | // the function/symbol in this case unless there is a bad assumption |
| 217 | // here due to inlined functions? |
| 218 | m_current_offset = m_current_pc.GetFileAddress() - m_start_pc.GetFileAddress(); |
| 219 | } |
| 220 | m_current_offset_backed_up_one = m_current_offset; |
| 221 | } |
| 222 | else |
| 223 | { |
| 224 | m_start_pc = m_current_pc; |
| 225 | m_current_offset = -1; |
| 226 | m_current_offset_backed_up_one = -1; |
| 227 | } |
| 228 | |
| 229 | // We've set m_frame_type and m_sym_ctx before these calls. |
| 230 | |
| 231 | m_fast_unwind_plan_sp = GetFastUnwindPlanForFrame (); |
| 232 | m_full_unwind_plan_sp = GetFullUnwindPlanForFrame (); |
| 233 | |
| 234 | UnwindPlan::RowSP active_row; |
| 235 | lldb::RegisterKind row_register_kind = eRegisterKindGeneric; |
| 236 | if (m_full_unwind_plan_sp && m_full_unwind_plan_sp->PlanValidAtAddress (m_current_pc)) |
| 237 | { |
| 238 | active_row = m_full_unwind_plan_sp->GetRowForFunctionOffset (m_current_offset); |
| 239 | row_register_kind = m_full_unwind_plan_sp->GetRegisterKind (); |
| 240 | if (active_row.get() && log) |
| 241 | { |
| 242 | StreamString active_row_strm; |
| 243 | active_row->Dump(active_row_strm, m_full_unwind_plan_sp.get(), &m_thread, m_start_pc.GetLoadAddress(exe_ctx.GetTargetPtr())); |
| 244 | UnwindLogMsg ("%s", active_row_strm.GetString().c_str()); |
| 245 | } |
| 246 | } |
| 247 | |
| 248 | if (!active_row.get()) |
| 249 | { |
| 250 | UnwindLogMsg ("could not find an unwindplan row for this frame's pc"); |
| 251 | m_frame_type = eNotAValidFrame; |
| 252 | return; |
| 253 | } |
| 254 | |
| 255 | |
| 256 | if (!ReadCFAValueForRow (row_register_kind, active_row, m_cfa)) |
| 257 | { |
| 258 | UnwindLogMsg ("could not read CFA register for this frame."); |
| 259 | m_frame_type = eNotAValidFrame; |
| 260 | return; |
| 261 | } |
| 262 | |
| 263 | UnwindLogMsg ("initialized frame current pc is 0x%" PRIx64"l" "x" " cfa is 0x%" PRIx64"l" "x" " using %s UnwindPlan", |
| 264 | (uint64_t) m_current_pc.GetLoadAddress (exe_ctx.GetTargetPtr()), |
| 265 | (uint64_t) m_cfa, |
| 266 | m_full_unwind_plan_sp->GetSourceName().GetCString()); |
| 267 | } |
| 268 | |
| 269 | // Initialize a RegisterContextLLDB for the non-zeroth frame -- rely on the RegisterContextLLDB "below" it |
| 270 | // to provide things like its current pc value. |
| 271 | |
| 272 | void |
| 273 | RegisterContextLLDB::InitializeNonZerothFrame() |
| 274 | { |
| 275 | Log *log(GetLogIfAllCategoriesSet (LIBLLDB_LOG_UNWIND(1u << 15))); |
| 276 | if (IsFrameZero ()) |
| 277 | { |
| 278 | m_frame_type = eNotAValidFrame; |
| 279 | UnwindLogMsg ("non-zeroth frame tests positive for IsFrameZero -- that shouldn't happen."); |
| 280 | return; |
| 281 | } |
| 282 | |
| 283 | if (!GetNextFrame().get() || !GetNextFrame()->IsValid()) |
| 284 | { |
| 285 | m_frame_type = eNotAValidFrame; |
| 286 | UnwindLogMsg ("Could not get next frame, marking this frame as invalid."); |
| 287 | return; |
| 288 | } |
| 289 | if (!m_thread.GetRegisterContext()) |
| 290 | { |
| 291 | m_frame_type = eNotAValidFrame; |
| 292 | UnwindLogMsg ("Could not get register context for this thread, marking this frame as invalid."); |
| 293 | return; |
| 294 | } |
| 295 | |
| 296 | addr_t pc; |
| 297 | if (!ReadGPRValue (eRegisterKindGeneric, LLDB_REGNUM_GENERIC_PC0, pc)) |
| 298 | { |
| 299 | UnwindLogMsg ("could not get pc value"); |
| 300 | m_frame_type = eNotAValidFrame; |
| 301 | return; |
| 302 | } |
| 303 | |
| 304 | if (log) |
| 305 | { |
| 306 | UnwindLogMsg ("pc = 0x%" PRIx64"l" "x", pc); |
| 307 | addr_t reg_val; |
| 308 | if (ReadGPRValue (eRegisterKindGeneric, LLDB_REGNUM_GENERIC_FP2, reg_val)) |
| 309 | UnwindLogMsg ("fp = 0x%" PRIx64"l" "x", reg_val); |
| 310 | if (ReadGPRValue (eRegisterKindGeneric, LLDB_REGNUM_GENERIC_SP1, reg_val)) |
| 311 | UnwindLogMsg ("sp = 0x%" PRIx64"l" "x", reg_val); |
| 312 | } |
| 313 | |
| 314 | // A pc of 0x0 means it's the end of the stack crawl unless we're above a trap handler function |
| 315 | bool above_trap_handler = false; |
| 316 | if (GetNextFrame().get() && GetNextFrame()->IsValid() && GetNextFrame()->IsTrapHandlerFrame()) |
| 317 | above_trap_handler = true; |
| 318 | |
| 319 | if (pc == 0 || pc == 0x1) |
| 320 | { |
| 321 | if (above_trap_handler == false) |
| 322 | { |
| 323 | m_frame_type = eNotAValidFrame; |
| 324 | UnwindLogMsg ("this frame has a pc of 0x0"); |
| 325 | return; |
| 326 | } |
| 327 | } |
| 328 | |
| 329 | ExecutionContext exe_ctx(m_thread.shared_from_this()); |
| 330 | Process *process = exe_ctx.GetProcessPtr(); |
| 331 | // Let ABIs fixup code addresses to make sure they are valid. In ARM ABIs |
| 332 | // this will strip bit zero in case we read a PC from memory or from the LR. |
| 333 | ABI *abi = process->GetABI().get(); |
| 334 | if (abi) |
| 335 | pc = abi->FixCodeAddress(pc); |
| 336 | |
| 337 | m_current_pc.SetLoadAddress (pc, &process->GetTarget()); |
| 338 | |
| 339 | // If we don't have a Module for some reason, we're not going to find symbol/function information - just |
| 340 | // stick in some reasonable defaults and hope we can unwind past this frame. |
| 341 | ModuleSP pc_module_sp (m_current_pc.GetModule()); |
| 342 | if (!m_current_pc.IsValid() || !pc_module_sp) |
| 343 | { |
| 344 | UnwindLogMsg ("using architectural default unwind method"); |
| 345 | |
| 346 | // Test the pc value to see if we know it's in an unmapped/non-executable region of memory. |
| 347 | uint32_t permissions; |
| 348 | if (process->GetLoadAddressPermissions(pc, permissions) |
| 349 | && (permissions & ePermissionsExecutable) == 0) |
| 350 | { |
| 351 | // If this is the second frame off the stack, we may have unwound the first frame |
| 352 | // incorrectly. But using the architecture default unwind plan may get us back on |
| 353 | // track -- albeit possibly skipping a real frame. Give this frame a clearly-invalid |
| 354 | // pc and see if we can get any further. |
| 355 | if (GetNextFrame().get() && GetNextFrame()->IsValid() && GetNextFrame()->IsFrameZero()) |
| 356 | { |
| 357 | UnwindLogMsg ("had a pc of 0x%" PRIx64"l" "x" " which is not in executable memory but on frame 1 -- allowing it once.", |
| 358 | (uint64_t) pc); |
| 359 | m_frame_type = eSkipFrame; |
| 360 | } |
| 361 | else |
| 362 | { |
| 363 | // anywhere other than the second frame, a non-executable pc means we're off in the weeds -- stop now. |
| 364 | m_frame_type = eNotAValidFrame; |
| 365 | UnwindLogMsg ("pc is in a non-executable section of memory and this isn't the 2nd frame in the stack walk."); |
| 366 | return; |
| 367 | } |
| 368 | } |
| 369 | |
| 370 | if (abi) |
| 371 | { |
| 372 | m_fast_unwind_plan_sp.reset (); |
| 373 | m_full_unwind_plan_sp.reset (new UnwindPlan (lldb::eRegisterKindGeneric)); |
| 374 | abi->CreateDefaultUnwindPlan(*m_full_unwind_plan_sp); |
| 375 | if (m_frame_type != eSkipFrame) // don't override eSkipFrame |
| 376 | { |
| 377 | m_frame_type = eNormalFrame; |
| 378 | } |
| 379 | m_all_registers_available = false; |
| 380 | m_current_offset = -1; |
| 381 | m_current_offset_backed_up_one = -1; |
| 382 | RegisterKind row_register_kind = m_full_unwind_plan_sp->GetRegisterKind (); |
| 383 | UnwindPlan::RowSP row = m_full_unwind_plan_sp->GetRowForFunctionOffset(0); |
| 384 | if (row.get()) |
| 385 | { |
| 386 | if (!ReadCFAValueForRow (row_register_kind, row, m_cfa)) |
| 387 | { |
| 388 | UnwindLogMsg ("failed to get cfa value"); |
| 389 | if (m_frame_type != eSkipFrame) // don't override eSkipFrame |
| 390 | { |
| 391 | m_frame_type = eNotAValidFrame; |
| 392 | } |
| 393 | return; |
| 394 | } |
| 395 | |
| 396 | // A couple of sanity checks.. |
| 397 | if (m_cfa == LLDB_INVALID_ADDRESS(18446744073709551615UL) || m_cfa == 0 || m_cfa == 1) |
| 398 | { |
| 399 | UnwindLogMsg ("could not find a valid cfa address"); |
| 400 | m_frame_type = eNotAValidFrame; |
| 401 | return; |
| 402 | } |
| 403 | |
| 404 | // m_cfa should point into the stack memory; if we can query memory region permissions, |
| 405 | // see if the memory is allocated & readable. |
| 406 | if (process->GetLoadAddressPermissions(m_cfa, permissions) |
| 407 | && (permissions & ePermissionsReadable) == 0) |
| 408 | { |
| 409 | m_frame_type = eNotAValidFrame; |
| 410 | UnwindLogMsg ("the CFA points to a region of memory that is not readable"); |
| 411 | return; |
| 412 | } |
| 413 | } |
| 414 | else |
| 415 | { |
| 416 | UnwindLogMsg ("could not find a row for function offset zero"); |
| 417 | m_frame_type = eNotAValidFrame; |
| 418 | return; |
| 419 | } |
| 420 | |
| 421 | if (CheckIfLoopingStack ()) |
| 422 | { |
| 423 | TryFallbackUnwindPlan(); |
| 424 | if (CheckIfLoopingStack ()) |
| 425 | { |
| 426 | UnwindLogMsg ("same CFA address as next frame, assuming the unwind is looping - stopping"); |
| 427 | m_frame_type = eNotAValidFrame; |
| 428 | return; |
| 429 | } |
| 430 | } |
| 431 | |
| 432 | UnwindLogMsg ("initialized frame cfa is 0x%" PRIx64"l" "x", (uint64_t) m_cfa); |
| 433 | return; |
| 434 | } |
| 435 | m_frame_type = eNotAValidFrame; |
| 436 | UnwindLogMsg ("could not find any symbol for this pc, or a default unwind plan, to continue unwind."); |
| 437 | return; |
| 438 | } |
| 439 | |
| 440 | bool resolve_tail_call_address = true; // m_current_pc can be one past the address range of the function... |
| 441 | // This will handle the case where the saved pc does not point to |
| 442 | // a function/symbol because it is beyond the bounds of the correct |
| 443 | // function and there's no symbol there. ResolveSymbolContextForAddress |
| 444 | // will fail to find a symbol, back up the pc by 1 and re-search. |
| 445 | const uint32_t resolve_scope = eSymbolContextFunction | eSymbolContextSymbol; |
| 446 | uint32_t resolved_scope = pc_module_sp->ResolveSymbolContextForAddress (m_current_pc, |
| 447 | resolve_scope, |
| 448 | m_sym_ctx, resolve_tail_call_address); |
| 449 | |
| 450 | // We require either a symbol or function in the symbols context to be successfully |
| 451 | // filled in or this context is of no use to us. |
| 452 | if (resolve_scope & resolved_scope) |
| 453 | { |
| 454 | m_sym_ctx_valid = true; |
| 455 | } |
| 456 | |
| 457 | if (m_sym_ctx.symbol) |
| 458 | { |
| 459 | UnwindLogMsg ("with pc value of 0x%" PRIx64"l" "x" ", symbol name is '%s'", |
| 460 | pc, m_sym_ctx.symbol == NULL__null ? "" : m_sym_ctx.symbol->GetName().AsCString()); |
| 461 | } |
| 462 | else if (m_sym_ctx.function) |
| 463 | { |
| 464 | UnwindLogMsg ("with pc value of 0x%" PRIx64"l" "x" ", function name is '%s'", |
| 465 | pc, m_sym_ctx.symbol == NULL__null ? "" : m_sym_ctx.function->GetName().AsCString()); |
| 466 | } |
| 467 | else |
| 468 | { |
| 469 | UnwindLogMsg ("with pc value of 0x%" PRIx64"l" "x" ", no symbol/function name is known.", pc); |
| 470 | } |
| 471 | |
| 472 | AddressRange addr_range; |
| 473 | if (!m_sym_ctx.GetAddressRange (resolve_scope, 0, false, addr_range)) |
| 474 | { |
| 475 | m_sym_ctx_valid = false; |
| 476 | } |
| 477 | |
| 478 | bool decr_pc_and_recompute_addr_range = false; |
| 479 | |
| 480 | // If the symbol lookup failed... |
| 481 | if (m_sym_ctx_valid == false) |
| 482 | decr_pc_and_recompute_addr_range = true; |
| 483 | |
| 484 | // Or if we're in the middle of the stack (and not "above" an asynchronous event like sigtramp), |
| 485 | // and our "current" pc is the start of a function... |
| 486 | if (m_sym_ctx_valid |
| 487 | && GetNextFrame()->m_frame_type != eTrapHandlerFrame |
| 488 | && GetNextFrame()->m_frame_type != eDebuggerFrame |
| 489 | && addr_range.GetBaseAddress().IsValid() |
| 490 | && addr_range.GetBaseAddress().GetSection() == m_current_pc.GetSection() |
| 491 | && addr_range.GetBaseAddress().GetOffset() == m_current_pc.GetOffset()) |
| 492 | { |
| 493 | decr_pc_and_recompute_addr_range = true; |
| 494 | } |
| 495 | |
| 496 | // We need to back up the pc by 1 byte and re-search for the Symbol to handle the case where the "saved pc" |
| 497 | // value is pointing to the next function, e.g. if a function ends with a CALL instruction. |
| 498 | // FIXME this may need to be an architectural-dependent behavior; if so we'll need to add a member function |
| 499 | // to the ABI plugin and consult that. |
| 500 | if (decr_pc_and_recompute_addr_range) |
| 501 | { |
| 502 | UnwindLogMsg ("Backing up the pc value of 0x%" PRIx64"l" "x" " by 1 and re-doing symbol lookup; old symbol was %s", |
| 503 | pc, m_sym_ctx.symbol == NULL__null ? "" : m_sym_ctx.symbol->GetName().AsCString()); |
| 504 | Address temporary_pc; |
| 505 | temporary_pc.SetLoadAddress (pc - 1, &process->GetTarget()); |
| 506 | m_sym_ctx.Clear (false); |
| 507 | m_sym_ctx_valid = false; |
| 508 | uint32_t resolve_scope = eSymbolContextFunction | eSymbolContextSymbol; |
| 509 | |
| 510 | ModuleSP temporary_module_sp = temporary_pc.GetModule(); |
| 511 | if (temporary_module_sp && |
| 512 | temporary_module_sp->ResolveSymbolContextForAddress (temporary_pc, resolve_scope, m_sym_ctx) & resolve_scope) |
| 513 | { |
| 514 | if (m_sym_ctx.GetAddressRange (resolve_scope, 0, false, addr_range)) |
| 515 | m_sym_ctx_valid = true; |
| 516 | } |
| 517 | UnwindLogMsg ("Symbol is now %s", m_sym_ctx.symbol == NULL__null ? "" : m_sym_ctx.symbol->GetName().AsCString()); |
| 518 | } |
| 519 | |
| 520 | // If we were able to find a symbol/function, set addr_range_ptr to the bounds of that symbol/function. |
| 521 | // else treat the current pc value as the start_pc and record no offset. |
| 522 | if (addr_range.GetBaseAddress().IsValid()) |
| 523 | { |
| 524 | m_start_pc = addr_range.GetBaseAddress(); |
| 525 | m_current_offset = pc - m_start_pc.GetLoadAddress (&process->GetTarget()); |
| 526 | m_current_offset_backed_up_one = m_current_offset; |
| 527 | if (decr_pc_and_recompute_addr_range && m_current_offset_backed_up_one > 0) |
| 528 | { |
| 529 | m_current_offset_backed_up_one--; |
| 530 | if (m_sym_ctx_valid) |
| 531 | { |
| 532 | m_current_pc.SetLoadAddress (pc - 1, &process->GetTarget()); |
| 533 | } |
| 534 | } |
| 535 | } |
| 536 | else |
| 537 | { |
| 538 | m_start_pc = m_current_pc; |
| 539 | m_current_offset = -1; |
| 540 | m_current_offset_backed_up_one = -1; |
| 541 | } |
| 542 | |
| 543 | if (IsTrapHandlerSymbol (process, m_sym_ctx)) |
| 544 | { |
| 545 | m_frame_type = eTrapHandlerFrame; |
| 546 | } |
| 547 | else |
| 548 | { |
| 549 | // FIXME: Detect eDebuggerFrame here. |
| 550 | if (m_frame_type != eSkipFrame) // don't override eSkipFrame |
| 551 | { |
| 552 | m_frame_type = eNormalFrame; |
| 553 | } |
| 554 | } |
| 555 | |
| 556 | // We've set m_frame_type and m_sym_ctx before this call. |
| 557 | m_fast_unwind_plan_sp = GetFastUnwindPlanForFrame (); |
| 558 | |
| 559 | UnwindPlan::RowSP active_row; |
| 560 | RegisterKind row_register_kind = eRegisterKindGeneric; |
| 561 | |
| 562 | // Try to get by with just the fast UnwindPlan if possible - the full UnwindPlan may be expensive to get |
| 563 | // (e.g. if we have to parse the entire eh_frame section of an ObjectFile for the first time.) |
| 564 | |
| 565 | if (m_fast_unwind_plan_sp && m_fast_unwind_plan_sp->PlanValidAtAddress (m_current_pc)) |
| 566 | { |
| 567 | active_row = m_fast_unwind_plan_sp->GetRowForFunctionOffset (m_current_offset); |
| 568 | row_register_kind = m_fast_unwind_plan_sp->GetRegisterKind (); |
| 569 | if (active_row.get() && log) |
| 570 | { |
| 571 | StreamString active_row_strm; |
| 572 | active_row->Dump(active_row_strm, m_fast_unwind_plan_sp.get(), &m_thread, m_start_pc.GetLoadAddress(exe_ctx.GetTargetPtr())); |
| 573 | UnwindLogMsg ("active row: %s", active_row_strm.GetString().c_str()); |
| 574 | } |
| 575 | } |
| 576 | else |
| 577 | { |
| 578 | m_full_unwind_plan_sp = GetFullUnwindPlanForFrame (); |
| 579 | int valid_offset = -1; |
| 580 | if (IsUnwindPlanValidForCurrentPC(m_full_unwind_plan_sp, valid_offset)) |
| 581 | { |
| 582 | active_row = m_full_unwind_plan_sp->GetRowForFunctionOffset (valid_offset); |
| 583 | row_register_kind = m_full_unwind_plan_sp->GetRegisterKind (); |
| 584 | if (active_row.get() && log) |
| 585 | { |
| 586 | StreamString active_row_strm; |
| 587 | active_row->Dump(active_row_strm, m_full_unwind_plan_sp.get(), &m_thread, m_start_pc.GetLoadAddress(exe_ctx.GetTargetPtr())); |
| 588 | UnwindLogMsg ("active row: %s", active_row_strm.GetString().c_str()); |
| 589 | } |
| 590 | } |
| 591 | } |
| 592 | |
| 593 | if (!active_row.get()) |
| 594 | { |
| 595 | m_frame_type = eNotAValidFrame; |
| 596 | UnwindLogMsg ("could not find unwind row for this pc"); |
| 597 | return; |
| 598 | } |
| 599 | |
| 600 | if (!ReadCFAValueForRow (row_register_kind, active_row, m_cfa)) |
| 601 | { |
| 602 | UnwindLogMsg ("failed to get cfa reg %d/%d", row_register_kind, active_row->GetCFARegister()); |
| 603 | m_frame_type = eNotAValidFrame; |
| 604 | return; |
| 605 | } |
| 606 | |
| 607 | UnwindLogMsg ("m_cfa = 0x%" PRIx64"l" "x", m_cfa); |
| 608 | |
| 609 | if (CheckIfLoopingStack ()) |
| 610 | { |
| 611 | TryFallbackUnwindPlan(); |
| 612 | if (CheckIfLoopingStack ()) |
| 613 | { |
| 614 | UnwindLogMsg ("same CFA address as next frame, assuming the unwind is looping - stopping"); |
| 615 | m_frame_type = eNotAValidFrame; |
| 616 | return; |
| 617 | } |
| 618 | } |
| 619 | |
| 620 | UnwindLogMsg ("initialized frame current pc is 0x%" PRIx64"l" "x" " cfa is 0x%" PRIx64"l" "x", |
| 621 | (uint64_t) m_current_pc.GetLoadAddress (exe_ctx.GetTargetPtr()), (uint64_t) m_cfa); |
| 622 | } |
| 623 | |
| 624 | bool |
| 625 | RegisterContextLLDB::CheckIfLoopingStack () |
| 626 | { |
| 627 | // If we have a bad stack setup, we can get the same CFA value multiple times -- or even |
| 628 | // more devious, we can actually oscillate between two CFA values. Detect that here and |
| 629 | // break out to avoid a possible infinite loop in lldb trying to unwind the stack. |
| 630 | addr_t next_frame_cfa; |
| 631 | addr_t next_next_frame_cfa = LLDB_INVALID_ADDRESS(18446744073709551615UL); |
| 632 | if (GetNextFrame().get() && GetNextFrame()->GetCFA(next_frame_cfa)) |
| 633 | { |
| 634 | if (next_frame_cfa == m_cfa) |
| 635 | { |
| 636 | // We have a loop in the stack unwind |
| 637 | return true; |
| 638 | } |
| 639 | if (GetNextFrame()->GetNextFrame().get() && GetNextFrame()->GetNextFrame()->GetCFA(next_next_frame_cfa) |
| 640 | && next_next_frame_cfa == m_cfa) |
| 641 | { |
| 642 | // We have a loop in the stack unwind |
| 643 | return true; |
| 644 | } |
| 645 | } |
| 646 | return false; |
| 647 | } |
| 648 | |
| 649 | |
| 650 | bool |
| 651 | RegisterContextLLDB::IsFrameZero () const |
| 652 | { |
| 653 | return m_frame_number == 0; |
| 654 | } |
| 655 | |
| 656 | |
| 657 | // Find a fast unwind plan for this frame, if possible. |
| 658 | // |
| 659 | // On entry to this method, |
| 660 | // |
| 661 | // 1. m_frame_type should already be set to eTrapHandlerFrame/eDebuggerFrame if either of those are correct, |
| 662 | // 2. m_sym_ctx should already be filled in, and |
| 663 | // 3. m_current_pc should have the current pc value for this frame |
| 664 | // 4. m_current_offset_backed_up_one should have the current byte offset into the function, maybe backed up by 1, -1 if unknown |
| 665 | |
| 666 | UnwindPlanSP |
| 667 | RegisterContextLLDB::GetFastUnwindPlanForFrame () |
| 668 | { |
| 669 | UnwindPlanSP unwind_plan_sp; |
| 670 | ModuleSP pc_module_sp (m_current_pc.GetModule()); |
| 671 | |
| 672 | if (!m_current_pc.IsValid() || !pc_module_sp || pc_module_sp->GetObjectFile() == NULL__null) |
| 673 | return unwind_plan_sp; |
| 674 | |
| 675 | if (IsFrameZero ()) |
| 676 | return unwind_plan_sp; |
| 677 | |
| 678 | FuncUnwindersSP func_unwinders_sp (pc_module_sp->GetObjectFile()->GetUnwindTable().GetFuncUnwindersContainingAddress (m_current_pc, m_sym_ctx)); |
| 679 | if (!func_unwinders_sp) |
| 680 | return unwind_plan_sp; |
| 681 | |
| 682 | // If we're in _sigtramp(), unwinding past this frame requires special knowledge. |
| 683 | if (m_frame_type == eTrapHandlerFrame || m_frame_type == eDebuggerFrame) |
| 684 | return unwind_plan_sp; |
| 685 | |
| 686 | unwind_plan_sp = func_unwinders_sp->GetUnwindPlanFastUnwind (m_thread); |
| 687 | if (unwind_plan_sp) |
| 688 | { |
| 689 | if (unwind_plan_sp->PlanValidAtAddress (m_current_pc)) |
| 690 | { |
| 691 | Log *log(GetLogIfAllCategoriesSet (LIBLLDB_LOG_UNWIND(1u << 15))); |
| 692 | if (log && log->GetVerbose()) |
| 693 | { |
| 694 | if (m_fast_unwind_plan_sp) |
| 695 | UnwindLogMsgVerbose ("frame, and has a fast UnwindPlan"); |
| 696 | else |
| 697 | UnwindLogMsgVerbose ("frame"); |
| 698 | } |
| 699 | m_frame_type = eNormalFrame; |
| 700 | return unwind_plan_sp; |
| 701 | } |
| 702 | else |
| 703 | { |
| 704 | unwind_plan_sp.reset(); |
| 705 | } |
| 706 | } |
| 707 | return unwind_plan_sp; |
| 708 | } |
| 709 | |
| 710 | // On entry to this method, |
| 711 | // |
| 712 | // 1. m_frame_type should already be set to eTrapHandlerFrame/eDebuggerFrame if either of those are correct, |
| 713 | // 2. m_sym_ctx should already be filled in, and |
| 714 | // 3. m_current_pc should have the current pc value for this frame |
| 715 | // 4. m_current_offset_backed_up_one should have the current byte offset into the function, maybe backed up by 1, -1 if unknown |
| 716 | |
| 717 | UnwindPlanSP |
| 718 | RegisterContextLLDB::GetFullUnwindPlanForFrame () |
| 719 | { |
| 720 | UnwindPlanSP unwind_plan_sp; |
| 721 | UnwindPlanSP arch_default_unwind_plan_sp; |
| 722 | ExecutionContext exe_ctx(m_thread.shared_from_this()); |
| 723 | Process *process = exe_ctx.GetProcessPtr(); |
| 724 | ABI *abi = process ? process->GetABI().get() : NULL__null; |
| 725 | if (abi) |
| 726 | { |
| 727 | arch_default_unwind_plan_sp.reset (new UnwindPlan (lldb::eRegisterKindGeneric)); |
| 728 | abi->CreateDefaultUnwindPlan(*arch_default_unwind_plan_sp); |
| 729 | } |
| 730 | else |
| 731 | { |
| 732 | UnwindLogMsg ("unable to get architectural default UnwindPlan from ABI plugin"); |
| 733 | } |
| 734 | |
| 735 | bool behaves_like_zeroth_frame = false; |
| 736 | if (IsFrameZero () |
| 737 | || GetNextFrame()->m_frame_type == eTrapHandlerFrame |
| 738 | || GetNextFrame()->m_frame_type == eDebuggerFrame) |
| 739 | { |
| 740 | behaves_like_zeroth_frame = true; |
| 741 | // If this frame behaves like a 0th frame (currently executing or |
| 742 | // interrupted asynchronously), all registers can be retrieved. |
| 743 | m_all_registers_available = true; |
| 744 | } |
| 745 | |
| 746 | // If we've done a jmp 0x0 / bl 0x0 (called through a null function pointer) so the pc is 0x0 |
| 747 | // in the zeroth frame, we need to use the "unwind at first instruction" arch default UnwindPlan |
| 748 | // Also, if this Process can report on memory region attributes, any non-executable region means |
| 749 | // we jumped through a bad function pointer - handle the same way as 0x0. |
| 750 | // Note, if we have a symbol context & a symbol, we don't want to follow this code path. This is |
| 751 | // for jumping to memory regions without any information available. |
| 752 | |
| 753 | if ((!m_sym_ctx_valid || (m_sym_ctx.function == NULL__null && m_sym_ctx.symbol == NULL__null)) && behaves_like_zeroth_frame && m_current_pc.IsValid()) |
| 754 | { |
| 755 | uint32_t permissions; |
| 756 | addr_t current_pc_addr = m_current_pc.GetLoadAddress (exe_ctx.GetTargetPtr()); |
| 757 | if (current_pc_addr == 0 |
| 758 | || (process && |
| 759 | process->GetLoadAddressPermissions (current_pc_addr, permissions) |
| 760 | && (permissions & ePermissionsExecutable) == 0)) |
| 761 | { |
| 762 | if (abi) |
| 763 | { |
| 764 | unwind_plan_sp.reset (new UnwindPlan (lldb::eRegisterKindGeneric)); |
| 765 | abi->CreateFunctionEntryUnwindPlan(*unwind_plan_sp); |
| 766 | m_frame_type = eNormalFrame; |
| 767 | return unwind_plan_sp; |
| 768 | } |
| 769 | } |
| 770 | } |
| 771 | |
| 772 | // No Module for the current pc, try using the architecture default unwind. |
| 773 | ModuleSP pc_module_sp (m_current_pc.GetModule()); |
| 774 | if (!m_current_pc.IsValid() || !pc_module_sp || pc_module_sp->GetObjectFile() == NULL__null) |
| 775 | { |
| 776 | m_frame_type = eNormalFrame; |
| 777 | return arch_default_unwind_plan_sp; |
| 778 | } |
| 779 | |
| 780 | FuncUnwindersSP func_unwinders_sp; |
| 781 | if (m_sym_ctx_valid) |
| 782 | { |
| 783 | func_unwinders_sp = pc_module_sp->GetObjectFile()->GetUnwindTable().GetFuncUnwindersContainingAddress (m_current_pc, m_sym_ctx); |
| 784 | } |
| 785 | |
| 786 | // No FuncUnwinders available for this pc (i.e. a stripped function symbol and -fomit-frame-pointer). |
| 787 | // Try using the eh_frame information relative to the current PC, |
| 788 | // and finally fall back on the architectural default unwind. |
| 789 | if (!func_unwinders_sp) |
| 790 | { |
| 791 | DWARFCallFrameInfo *eh_frame = pc_module_sp && pc_module_sp->GetObjectFile() ? |
| 792 | pc_module_sp->GetObjectFile()->GetUnwindTable().GetEHFrameInfo() : nullptr; |
| 793 | |
| 794 | m_frame_type = eNormalFrame; |
| 795 | if (eh_frame && m_current_pc.IsValid()) |
| 796 | { |
| 797 | unwind_plan_sp.reset (new UnwindPlan (lldb::eRegisterKindGeneric)); |
| 798 | // Even with -fomit-frame-pointer, we can try eh_frame to get back on track. |
| 799 | if (eh_frame->GetUnwindPlan (m_current_pc, *unwind_plan_sp)) |
| 800 | return unwind_plan_sp; |
| 801 | else |
| 802 | unwind_plan_sp.reset(); |
| 803 | } |
| 804 | return arch_default_unwind_plan_sp; |
| 805 | } |
| 806 | |
| 807 | // If we're in _sigtramp(), unwinding past this frame requires special knowledge. On Mac OS X this knowledge |
| 808 | // is properly encoded in the eh_frame section, so prefer that if available. |
| 809 | // On other platforms we may need to provide a platform-specific UnwindPlan which encodes the details of |
| 810 | // how to unwind out of sigtramp. |
| 811 | if (m_frame_type == eTrapHandlerFrame && process) |
| 812 | { |
| 813 | m_fast_unwind_plan_sp.reset(); |
| 814 | unwind_plan_sp = func_unwinders_sp->GetEHFrameUnwindPlan (process->GetTarget(), m_current_offset_backed_up_one); |
| 815 | if (unwind_plan_sp && unwind_plan_sp->PlanValidAtAddress (m_current_pc) && unwind_plan_sp->GetSourcedFromCompiler() == eLazyBoolYes) |
| 816 | { |
| 817 | return unwind_plan_sp; |
| 818 | } |
| 819 | } |
| 820 | |
| 821 | // Ask the DynamicLoader if the eh_frame CFI should be trusted in this frame even when it's frame zero |
| 822 | // This comes up if we have hand-written functions in a Module and hand-written eh_frame. The assembly |
| 823 | // instruction inspection may fail and the eh_frame CFI were probably written with some care to do the |
| 824 | // right thing. It'd be nice if there was a way to ask the eh_frame directly if it is asynchronous |
| 825 | // (can be trusted at every instruction point) or synchronous (the normal case - only at call sites). |
| 826 | // But there is not. |
| 827 | if (process && process->GetDynamicLoader() && process->GetDynamicLoader()->AlwaysRelyOnEHUnwindInfo (m_sym_ctx)) |
| 828 | { |
| 829 | // We must specifically call the GetEHFrameUnwindPlan() method here -- normally we would |
| 830 | // call GetUnwindPlanAtCallSite() -- because CallSite may return an unwind plan sourced from |
| 831 | // either eh_frame (that's what we intend) or compact unwind (this won't work) |
| 832 | unwind_plan_sp = func_unwinders_sp->GetEHFrameUnwindPlan (process->GetTarget(), m_current_offset_backed_up_one); |
| 833 | if (unwind_plan_sp && unwind_plan_sp->PlanValidAtAddress (m_current_pc)) |
| 834 | { |
| 835 | UnwindLogMsgVerbose ("frame uses %s for full UnwindPlan because the DynamicLoader suggested we prefer it", |
| 836 | unwind_plan_sp->GetSourceName().GetCString()); |
| 837 | return unwind_plan_sp; |
| 838 | } |
| 839 | } |
| 840 | |
| 841 | // Typically the NonCallSite UnwindPlan is the unwind created by inspecting the assembly language instructions |
| 842 | if (behaves_like_zeroth_frame && process) |
| 843 | { |
| 844 | unwind_plan_sp = func_unwinders_sp->GetUnwindPlanAtNonCallSite (process->GetTarget(), m_thread, m_current_offset_backed_up_one); |
| 845 | if (unwind_plan_sp && unwind_plan_sp->PlanValidAtAddress (m_current_pc)) |
| 846 | { |
| 847 | if (unwind_plan_sp->GetSourcedFromCompiler() == eLazyBoolNo) |
| 848 | { |
| 849 | // We probably have an UnwindPlan created by inspecting assembly instructions, and we probably |
| 850 | // don't have any eh_frame instructions available. |
| 851 | // The assembly profilers work really well with compiler-generated functions but hand-written |
| 852 | // assembly can be problematic. We'll set the architecture default UnwindPlan as our fallback |
| 853 | // UnwindPlan in case this doesn't work out when we try to unwind. |
| 854 | m_fallback_unwind_plan_sp = arch_default_unwind_plan_sp; |
| 855 | } |
| 856 | UnwindLogMsgVerbose ("frame uses %s for full UnwindPlan", unwind_plan_sp->GetSourceName().GetCString()); |
| 857 | return unwind_plan_sp; |
| 858 | } |
| 859 | } |
| 860 | |
| 861 | // Typically this is unwind info from an eh_frame section intended for exception handling; only valid at call sites |
| 862 | if (process) |
| 863 | { |
| 864 | unwind_plan_sp = func_unwinders_sp->GetUnwindPlanAtCallSite (process->GetTarget(), m_current_offset_backed_up_one); |
| 865 | } |
| 866 | int valid_offset = -1; |
| 867 | if (IsUnwindPlanValidForCurrentPC(unwind_plan_sp, valid_offset)) |
| 868 | { |
| 869 | UnwindLogMsgVerbose ("frame uses %s for full UnwindPlan", unwind_plan_sp->GetSourceName().GetCString()); |
| 870 | return unwind_plan_sp; |
| 871 | } |
| 872 | |
| 873 | // We'd prefer to use an UnwindPlan intended for call sites when we're at a call site but if we've |
| 874 | // struck out on that, fall back to using the non-call-site assembly inspection UnwindPlan if possible. |
| 875 | if (process) |
| 876 | { |
| 877 | unwind_plan_sp = func_unwinders_sp->GetUnwindPlanAtNonCallSite (process->GetTarget(), m_thread, m_current_offset_backed_up_one); |
| 878 | } |
| 879 | if (unwind_plan_sp && unwind_plan_sp->GetSourcedFromCompiler() == eLazyBoolNo) |
| 880 | { |
| 881 | // We probably have an UnwindPlan created by inspecting assembly instructions, and we probably |
| 882 | // don't have any eh_frame instructions available. |
| 883 | // The assembly profilers work really well with compiler-generated functions but hand-written |
| 884 | // assembly can be problematic. We'll set the architecture default UnwindPlan as our fallback |
| 885 | // UnwindPlan in case this doesn't work out when we try to unwind. |
| 886 | m_fallback_unwind_plan_sp = arch_default_unwind_plan_sp; |
| 887 | } |
| 888 | |
| 889 | if (IsUnwindPlanValidForCurrentPC(unwind_plan_sp, valid_offset)) |
| 890 | { |
| 891 | UnwindLogMsgVerbose ("frame uses %s for full UnwindPlan", unwind_plan_sp->GetSourceName().GetCString()); |
| 892 | return unwind_plan_sp; |
| 893 | } |
| 894 | |
| 895 | // If we're on the first instruction of a function, and we have an architectural default UnwindPlan |
| 896 | // for the initial instruction of a function, use that. |
| 897 | if (m_current_offset_backed_up_one == 0) |
| 898 | { |
| 899 | unwind_plan_sp = func_unwinders_sp->GetUnwindPlanArchitectureDefaultAtFunctionEntry (m_thread); |
| 900 | if (unwind_plan_sp) |
| 901 | { |
| 902 | UnwindLogMsgVerbose ("frame uses %s for full UnwindPlan", unwind_plan_sp->GetSourceName().GetCString()); |
| 903 | return unwind_plan_sp; |
| 904 | } |
| 905 | } |
| 906 | |
| 907 | // If nothing else, use the architectural default UnwindPlan and hope that does the job. |
| 908 | if (arch_default_unwind_plan_sp) |
| 909 | UnwindLogMsgVerbose ("frame uses %s for full UnwindPlan", arch_default_unwind_plan_sp->GetSourceName().GetCString()); |
| 910 | else |
| 911 | UnwindLogMsg ("Unable to find any UnwindPlan for full unwind of this frame."); |
| 912 | |
| 913 | return arch_default_unwind_plan_sp; |
| 914 | } |
| 915 | |
| 916 | |
| 917 | void |
| 918 | RegisterContextLLDB::InvalidateAllRegisters () |
| 919 | { |
| 920 | m_frame_type = eNotAValidFrame; |
| 921 | } |
| 922 | |
| 923 | size_t |
| 924 | RegisterContextLLDB::GetRegisterCount () |
| 925 | { |
| 926 | return m_thread.GetRegisterContext()->GetRegisterCount(); |
| 927 | } |
| 928 | |
| 929 | const RegisterInfo * |
| 930 | RegisterContextLLDB::GetRegisterInfoAtIndex (size_t reg) |
| 931 | { |
| 932 | return m_thread.GetRegisterContext()->GetRegisterInfoAtIndex (reg); |
| 933 | } |
| 934 | |
| 935 | size_t |
| 936 | RegisterContextLLDB::GetRegisterSetCount () |
| 937 | { |
| 938 | return m_thread.GetRegisterContext()->GetRegisterSetCount (); |
| 939 | } |
| 940 | |
| 941 | const RegisterSet * |
| 942 | RegisterContextLLDB::GetRegisterSet (size_t reg_set) |
| 943 | { |
| 944 | return m_thread.GetRegisterContext()->GetRegisterSet (reg_set); |
| 945 | } |
| 946 | |
| 947 | uint32_t |
| 948 | RegisterContextLLDB::ConvertRegisterKindToRegisterNumber (lldb::RegisterKind kind, uint32_t num) |
| 949 | { |
| 950 | return m_thread.GetRegisterContext()->ConvertRegisterKindToRegisterNumber (kind, num); |
| 951 | } |
| 952 | |
| 953 | bool |
| 954 | RegisterContextLLDB::ReadRegisterValueFromRegisterLocation (lldb_private::UnwindLLDB::RegisterLocation regloc, |
| 955 | const RegisterInfo *reg_info, |
| 956 | RegisterValue &value) |
| 957 | { |
| 958 | if (!IsValid()) |
| 959 | return false; |
| 960 | bool success = false; |
| 961 | |
| 962 | switch (regloc.type) |
| 963 | { |
| 964 | case UnwindLLDB::RegisterLocation::eRegisterInLiveRegisterContext: |
| 965 | { |
| 966 | const RegisterInfo *other_reg_info = GetRegisterInfoAtIndex(regloc.location.register_number); |
| 967 | |
| 968 | if (!other_reg_info) |
| 969 | return false; |
| 970 | |
| 971 | success = m_thread.GetRegisterContext()->ReadRegister (other_reg_info, value); |
| 972 | } |
| 973 | break; |
| 974 | case UnwindLLDB::RegisterLocation::eRegisterInRegister: |
| 975 | { |
| 976 | const RegisterInfo *other_reg_info = GetRegisterInfoAtIndex(regloc.location.register_number); |
| 977 | |
| 978 | if (!other_reg_info) |
| 979 | return false; |
| 980 | |
| 981 | if (IsFrameZero ()) |
| 982 | { |
| 983 | success = m_thread.GetRegisterContext()->ReadRegister (other_reg_info, value); |
| 984 | } |
| 985 | else |
| 986 | { |
| 987 | success = GetNextFrame()->ReadRegister (other_reg_info, value); |
| 988 | } |
| 989 | } |
| 990 | break; |
| 991 | case UnwindLLDB::RegisterLocation::eRegisterValueInferred: |
| 992 | success = value.SetUInt (regloc.location.inferred_value, reg_info->byte_size); |
| 993 | break; |
| 994 | |
| 995 | case UnwindLLDB::RegisterLocation::eRegisterNotSaved: |
| 996 | break; |
| 997 | case UnwindLLDB::RegisterLocation::eRegisterSavedAtHostMemoryLocation: |
| 998 | assert ("FIXME debugger inferior function call unwind")(("FIXME debugger inferior function call unwind") ? static_cast <void> (0) : __assert_fail ("\"FIXME debugger inferior function call unwind\"" , "/tmp/buildd/llvm-toolchain-snapshot-3.7~svn230168/tools/lldb/source/Plugins/Process/Utility/RegisterContextLLDB.cpp" , 998, __PRETTY_FUNCTION__)); |
| 999 | break; |
| 1000 | case UnwindLLDB::RegisterLocation::eRegisterSavedAtMemoryLocation: |
| 1001 | { |
| 1002 | Error error (ReadRegisterValueFromMemory(reg_info, |
| 1003 | regloc.location.target_memory_location, |
| 1004 | reg_info->byte_size, |
| 1005 | value)); |
| 1006 | success = error.Success(); |
| 1007 | } |
| 1008 | break; |
| 1009 | default: |
| 1010 | assert ("Unknown RegisterLocation type.")(("Unknown RegisterLocation type.") ? static_cast<void> (0) : __assert_fail ("\"Unknown RegisterLocation type.\"", "/tmp/buildd/llvm-toolchain-snapshot-3.7~svn230168/tools/lldb/source/Plugins/Process/Utility/RegisterContextLLDB.cpp" , 1010, __PRETTY_FUNCTION__)); |
| 1011 | break; |
| 1012 | } |
| 1013 | return success; |
| 1014 | } |
| 1015 | |
| 1016 | bool |
| 1017 | RegisterContextLLDB::WriteRegisterValueToRegisterLocation (lldb_private::UnwindLLDB::RegisterLocation regloc, |
| 1018 | const RegisterInfo *reg_info, |
| 1019 | const RegisterValue &value) |
| 1020 | { |
| 1021 | if (!IsValid()) |
| 1022 | return false; |
| 1023 | |
| 1024 | bool success = false; |
| 1025 | |
| 1026 | switch (regloc.type) |
| 1027 | { |
| 1028 | case UnwindLLDB::RegisterLocation::eRegisterInLiveRegisterContext: |
| 1029 | { |
| 1030 | const RegisterInfo *other_reg_info = GetRegisterInfoAtIndex(regloc.location.register_number); |
| 1031 | success = m_thread.GetRegisterContext()->WriteRegister (other_reg_info, value); |
| 1032 | } |
| 1033 | break; |
| 1034 | case UnwindLLDB::RegisterLocation::eRegisterInRegister: |
| 1035 | { |
| 1036 | const RegisterInfo *other_reg_info = GetRegisterInfoAtIndex(regloc.location.register_number); |
| 1037 | if (IsFrameZero ()) |
| 1038 | { |
| 1039 | success = m_thread.GetRegisterContext()->WriteRegister (other_reg_info, value); |
| 1040 | } |
| 1041 | else |
| 1042 | { |
| 1043 | success = GetNextFrame()->WriteRegister (other_reg_info, value); |
| 1044 | } |
| 1045 | } |
| 1046 | break; |
| 1047 | case UnwindLLDB::RegisterLocation::eRegisterValueInferred: |
| 1048 | case UnwindLLDB::RegisterLocation::eRegisterNotSaved: |
| 1049 | break; |
| 1050 | case UnwindLLDB::RegisterLocation::eRegisterSavedAtHostMemoryLocation: |
| 1051 | assert ("FIXME debugger inferior function call unwind")(("FIXME debugger inferior function call unwind") ? static_cast <void> (0) : __assert_fail ("\"FIXME debugger inferior function call unwind\"" , "/tmp/buildd/llvm-toolchain-snapshot-3.7~svn230168/tools/lldb/source/Plugins/Process/Utility/RegisterContextLLDB.cpp" , 1051, __PRETTY_FUNCTION__)); |
| 1052 | break; |
| 1053 | case UnwindLLDB::RegisterLocation::eRegisterSavedAtMemoryLocation: |
| 1054 | { |
| 1055 | Error error (WriteRegisterValueToMemory (reg_info, |
| 1056 | regloc.location.target_memory_location, |
| 1057 | reg_info->byte_size, |
| 1058 | value)); |
| 1059 | success = error.Success(); |
| 1060 | } |
| 1061 | break; |
| 1062 | default: |
| 1063 | assert ("Unknown RegisterLocation type.")(("Unknown RegisterLocation type.") ? static_cast<void> (0) : __assert_fail ("\"Unknown RegisterLocation type.\"", "/tmp/buildd/llvm-toolchain-snapshot-3.7~svn230168/tools/lldb/source/Plugins/Process/Utility/RegisterContextLLDB.cpp" , 1063, __PRETTY_FUNCTION__)); |
| 1064 | break; |
| 1065 | } |
| 1066 | return success; |
| 1067 | } |
| 1068 | |
| 1069 | |
| 1070 | bool |
| 1071 | RegisterContextLLDB::IsValid () const |
| 1072 | { |
| 1073 | return m_frame_type != eNotAValidFrame; |
| 1074 | } |
| 1075 | |
| 1076 | // After the final stack frame in a stack walk we'll get one invalid (eNotAValidFrame) stack frame -- |
| 1077 | // one past the end of the stack walk. But higher-level code will need to tell the differnece between |
| 1078 | // "the unwind plan below this frame failed" versus "we successfully completed the stack walk" so |
| 1079 | // this method helps to disambiguate that. |
| 1080 | |
| 1081 | bool |
| 1082 | RegisterContextLLDB::IsTrapHandlerFrame () const |
| 1083 | { |
| 1084 | return m_frame_type == eTrapHandlerFrame; |
| 1085 | } |
| 1086 | |
| 1087 | // A skip frame is a bogus frame on the stack -- but one where we're likely to find a real frame farther |
| 1088 | // up the stack if we keep looking. It's always the second frame in an unwind (i.e. the first frame after |
| 1089 | // frame zero) where unwinding can be the trickiest. Ideally we'll mark up this frame in some way so the |
| 1090 | // user knows we're displaying bad data and we may have skipped one frame of their real program in the |
| 1091 | // process of getting back on track. |
| 1092 | |
| 1093 | bool |
| 1094 | RegisterContextLLDB::IsSkipFrame () const |
| 1095 | { |
| 1096 | return m_frame_type == eSkipFrame; |
| 1097 | } |
| 1098 | |
| 1099 | bool |
| 1100 | RegisterContextLLDB::IsTrapHandlerSymbol (lldb_private::Process *process, const lldb_private::SymbolContext &m_sym_ctx) const |
| 1101 | { |
| 1102 | PlatformSP platform_sp (process->GetTarget().GetPlatform()); |
| 1103 | if (platform_sp) |
| 1104 | { |
| 1105 | const std::vector<ConstString> trap_handler_names (platform_sp->GetTrapHandlerSymbolNames()); |
| 1106 | for (ConstString name : trap_handler_names) |
| 1107 | { |
| 1108 | if ((m_sym_ctx.function && m_sym_ctx.function->GetName() == name) || |
| 1109 | (m_sym_ctx.symbol && m_sym_ctx.symbol->GetName() == name)) |
| 1110 | { |
| 1111 | return true; |
| 1112 | } |
| 1113 | } |
| 1114 | } |
| 1115 | const std::vector<ConstString> user_specified_trap_handler_names (m_parent_unwind.GetUserSpecifiedTrapHandlerFunctionNames()); |
| 1116 | for (ConstString name : user_specified_trap_handler_names) |
| 1117 | { |
| 1118 | if ((m_sym_ctx.function && m_sym_ctx.function->GetName() == name) || |
| 1119 | (m_sym_ctx.symbol && m_sym_ctx.symbol->GetName() == name)) |
| 1120 | { |
| 1121 | return true; |
| 1122 | } |
| 1123 | } |
| 1124 | |
| 1125 | return false; |
| 1126 | } |
| 1127 | |
| 1128 | // Answer the question: Where did THIS frame save the CALLER frame ("previous" frame)'s register value? |
| 1129 | |
| 1130 | enum UnwindLLDB::RegisterSearchResult |
| 1131 | RegisterContextLLDB::SavedLocationForRegister (uint32_t lldb_regnum, lldb_private::UnwindLLDB::RegisterLocation ®loc) |
| 1132 | { |
| 1133 | RegisterNumber regnum (m_thread, eRegisterKindLLDB, lldb_regnum); |
| 1134 | |
| 1135 | // Have we already found this register location? |
| 1136 | if (!m_registers.empty()) |
| 1137 | { |
| 1138 | std::map<uint32_t, lldb_private::UnwindLLDB::RegisterLocation>::const_iterator iterator; |
| 1139 | iterator = m_registers.find (regnum.GetAsKind (eRegisterKindLLDB)); |
| 1140 | if (iterator != m_registers.end()) |
| 1141 | { |
| 1142 | regloc = iterator->second; |
| 1143 | UnwindLogMsg ("supplying caller's saved %s (%d)'s location, cached", |
| 1144 | regnum.GetName(), regnum.GetAsKind (eRegisterKindLLDB)); |
| 1145 | return UnwindLLDB::RegisterSearchResult::eRegisterFound; |
| 1146 | } |
| 1147 | } |
| 1148 | |
| 1149 | // Look through the available UnwindPlans for the register location. |
| 1150 | |
| 1151 | UnwindPlan::Row::RegisterLocation unwindplan_regloc; |
| 1152 | bool have_unwindplan_regloc = false; |
| 1153 | RegisterKind unwindplan_registerkind = kNumRegisterKinds; |
| 1154 | |
| 1155 | if (m_fast_unwind_plan_sp) |
| 1156 | { |
| 1157 | UnwindPlan::RowSP active_row = m_fast_unwind_plan_sp->GetRowForFunctionOffset (m_current_offset); |
| 1158 | unwindplan_registerkind = m_fast_unwind_plan_sp->GetRegisterKind (); |
| 1159 | if (regnum.GetAsKind (unwindplan_registerkind) == LLDB_INVALID_REGNUM(4294967295U)) |
| 1160 | { |
| 1161 | UnwindLogMsg ("could not convert lldb regnum %s (%d) into %d RegisterKind reg numbering scheme", |
| 1162 | regnum.GetName(), regnum.GetAsKind (eRegisterKindLLDB), (int) unwindplan_registerkind); |
| 1163 | return UnwindLLDB::RegisterSearchResult::eRegisterNotFound; |
| 1164 | } |
| 1165 | if (active_row->GetRegisterInfo (regnum.GetAsKind (unwindplan_registerkind), unwindplan_regloc)) |
| 1166 | { |
| 1167 | UnwindLogMsg ("supplying caller's saved %s (%d)'s location using FastUnwindPlan", |
| 1168 | regnum.GetName(), regnum.GetAsKind (eRegisterKindLLDB)); |
| 1169 | have_unwindplan_regloc = true; |
| 1170 | } |
| 1171 | } |
| 1172 | |
| 1173 | if (!have_unwindplan_regloc) |
| 1174 | { |
| 1175 | // m_full_unwind_plan_sp being NULL means that we haven't tried to find a full UnwindPlan yet |
| 1176 | if (!m_full_unwind_plan_sp) |
| 1177 | m_full_unwind_plan_sp = GetFullUnwindPlanForFrame (); |
| 1178 | |
| 1179 | if (m_full_unwind_plan_sp) |
| 1180 | { |
| 1181 | RegisterNumber pc_regnum (m_thread, eRegisterKindGeneric, LLDB_REGNUM_GENERIC_PC0); |
| 1182 | |
| 1183 | UnwindPlan::RowSP active_row = m_full_unwind_plan_sp->GetRowForFunctionOffset (m_current_offset); |
| 1184 | unwindplan_registerkind = m_full_unwind_plan_sp->GetRegisterKind (); |
| 1185 | |
| 1186 | RegisterNumber return_address_reg; |
| 1187 | |
| 1188 | // If we're fetching the saved pc and this UnwindPlan defines a ReturnAddress register (e.g. lr on arm), |
| 1189 | // look for the return address register number in the UnwindPlan's row. |
| 1190 | if (pc_regnum.IsValid() |
| 1191 | && pc_regnum == regnum |
| 1192 | && m_full_unwind_plan_sp->GetReturnAddressRegister() != LLDB_INVALID_REGNUM(4294967295U)) |
| 1193 | { |
| 1194 | |
| 1195 | return_address_reg.init (m_thread, m_full_unwind_plan_sp->GetRegisterKind(), m_full_unwind_plan_sp->GetReturnAddressRegister()); |
| 1196 | regnum = return_address_reg; |
| 1197 | UnwindLogMsg ("requested caller's saved PC but this UnwindPlan uses a RA reg; getting %s (%d) instead", |
| 1198 | return_address_reg.GetName(), return_address_reg.GetAsKind (eRegisterKindLLDB)); |
| 1199 | } |
| 1200 | else |
| 1201 | { |
| 1202 | if (regnum.GetAsKind (unwindplan_registerkind) == LLDB_INVALID_REGNUM(4294967295U)) |
| 1203 | { |
| 1204 | if (unwindplan_registerkind == eRegisterKindGeneric) |
| 1205 | { |
| 1206 | UnwindLogMsg ("could not convert lldb regnum %s (%d) into eRegisterKindGeneric reg numbering scheme", |
| 1207 | regnum.GetName(), regnum.GetAsKind (eRegisterKindLLDB)); |
| 1208 | } |
| 1209 | else |
| 1210 | { |
| 1211 | UnwindLogMsg ("could not convert lldb regnum %s (%d) into %d RegisterKind reg numbering scheme", |
| 1212 | regnum.GetName(), regnum.GetAsKind (eRegisterKindLLDB), (int) unwindplan_registerkind); |
| 1213 | } |
| 1214 | return UnwindLLDB::RegisterSearchResult::eRegisterNotFound; |
| 1215 | } |
| 1216 | } |
| 1217 | |
| 1218 | if (regnum.IsValid() |
| 1219 | && active_row->GetRegisterInfo (regnum.GetAsKind (unwindplan_registerkind), unwindplan_regloc)) |
| 1220 | { |
| 1221 | have_unwindplan_regloc = true; |
| 1222 | UnwindLogMsg ("supplying caller's saved %s (%d)'s location using %s UnwindPlan", |
| 1223 | regnum.GetName(), regnum.GetAsKind (eRegisterKindLLDB), |
| 1224 | m_full_unwind_plan_sp->GetSourceName().GetCString()); |
| 1225 | } |
| 1226 | |
| 1227 | // This is frame 0 and we're retrieving the PC and it's saved in a Return Address register and |
| 1228 | // it hasn't been saved anywhere yet -- that is, it's still live in the actual register. |
| 1229 | // Handle this specially. |
| 1230 | |
| 1231 | if (have_unwindplan_regloc == false |
| 1232 | && return_address_reg.IsValid() |
| 1233 | && IsFrameZero()) |
| 1234 | { |
| 1235 | if (return_address_reg.GetAsKind (eRegisterKindLLDB) != LLDB_INVALID_REGNUM(4294967295U)) |
| 1236 | { |
| 1237 | lldb_private::UnwindLLDB::RegisterLocation new_regloc; |
| 1238 | new_regloc.type = UnwindLLDB::RegisterLocation::eRegisterInLiveRegisterContext; |
| 1239 | new_regloc.location.register_number = return_address_reg.GetAsKind (eRegisterKindLLDB); |
| 1240 | m_registers[regnum.GetAsKind (eRegisterKindLLDB)] = new_regloc; |
| 1241 | regloc = new_regloc; |
| 1242 | UnwindLogMsg ("supplying caller's register %s (%d) from the live RegisterContext at frame 0, saved in %d", |
| 1243 | return_address_reg.GetName(), return_address_reg.GetAsKind (eRegisterKindLLDB), |
| 1244 | return_address_reg.GetAsKind (eRegisterKindLLDB)); |
| 1245 | return UnwindLLDB::RegisterSearchResult::eRegisterFound; |
| 1246 | } |
| 1247 | } |
| 1248 | |
| 1249 | // If this architecture stores the return address in a register (it defines a Return Address register) |
| 1250 | // and we're on a non-zero stack frame and the Full UnwindPlan says that the pc is stored in the |
| 1251 | // RA registers (e.g. lr on arm), then we know that the full unwindplan is not trustworthy -- this |
| 1252 | // is an impossible situation and the instruction emulation code has likely been misled. |
| 1253 | // If this stack frame meets those criteria, we need to throw away the Full UnwindPlan that the |
| 1254 | // instruction emulation came up with and fall back to the architecture's Default UnwindPlan so |
| 1255 | // the stack walk can get past this point. |
| 1256 | |
| 1257 | // Special note: If the Full UnwindPlan was generated from the compiler, don't second-guess it |
| 1258 | // when we're at a call site location. |
| 1259 | |
| 1260 | // arch_default_ra_regnum is the return address register # in the Full UnwindPlan register numbering |
| 1261 | RegisterNumber arch_default_ra_regnum (m_thread, eRegisterKindGeneric, LLDB_REGNUM_GENERIC_RA3); |
| 1262 | |
| 1263 | if (arch_default_ra_regnum.GetAsKind (unwindplan_registerkind) != LLDB_INVALID_REGNUM(4294967295U) |
| 1264 | && pc_regnum == regnum |
| 1265 | && unwindplan_regloc.IsInOtherRegister() |
| 1266 | && unwindplan_regloc.GetRegisterNumber() == arch_default_ra_regnum.GetAsKind (unwindplan_registerkind) |
| 1267 | && m_full_unwind_plan_sp->GetSourcedFromCompiler() != eLazyBoolYes |
| 1268 | && !m_all_registers_available) |
| 1269 | { |
| 1270 | UnwindLogMsg ("%s UnwindPlan tried to restore the pc from the link register but this is a non-zero frame", |
| 1271 | m_full_unwind_plan_sp->GetSourceName().GetCString()); |
| 1272 | |
| 1273 | // Throw away the full unwindplan; install the arch default unwindplan |
| 1274 | if (ForceSwitchToFallbackUnwindPlan()) |
| 1275 | { |
| 1276 | // Update for the possibly new unwind plan |
| 1277 | unwindplan_registerkind = m_full_unwind_plan_sp->GetRegisterKind (); |
| 1278 | UnwindPlan::RowSP active_row = m_full_unwind_plan_sp->GetRowForFunctionOffset (m_current_offset); |
| 1279 | |
| 1280 | // Sanity check: Verify that we can fetch a pc value and CFA value with this unwind plan |
| 1281 | |
| 1282 | RegisterNumber arch_default_pc_reg (m_thread, eRegisterKindGeneric, LLDB_REGNUM_GENERIC_PC0); |
| 1283 | bool can_fetch_pc_value = false; |
| 1284 | bool can_fetch_cfa = false; |
| 1285 | addr_t cfa_value; |
| 1286 | if (active_row) |
| 1287 | { |
| 1288 | if (arch_default_pc_reg.GetAsKind (unwindplan_registerkind) != LLDB_INVALID_REGNUM(4294967295U) |
| 1289 | && active_row->GetRegisterInfo (arch_default_pc_reg.GetAsKind (unwindplan_registerkind), unwindplan_regloc)) |
| 1290 | { |
| 1291 | can_fetch_pc_value = true; |
| 1292 | } |
| 1293 | if (ReadCFAValueForRow (unwindplan_registerkind, active_row, cfa_value)) |
| 1294 | { |
| 1295 | can_fetch_cfa = true; |
| 1296 | } |
| 1297 | } |
| 1298 | |
| 1299 | if (can_fetch_pc_value && can_fetch_cfa) |
| 1300 | { |
| 1301 | have_unwindplan_regloc = true; |
| 1302 | } |
| 1303 | else |
| 1304 | { |
| 1305 | have_unwindplan_regloc = false; |
| 1306 | } |
| 1307 | } |
| 1308 | else |
| 1309 | { |
| 1310 | // We were unable to fall back to another unwind plan |
| 1311 | have_unwindplan_regloc = false; |
| 1312 | } |
| 1313 | } |
| 1314 | } |
| 1315 | } |
| 1316 | |
| 1317 | if (have_unwindplan_regloc == false) |
| 1318 | { |
| 1319 | // Did the UnwindPlan fail to give us the caller's stack pointer? |
| 1320 | // The stack pointer is defined to be the same as THIS frame's CFA, so return the CFA value as |
| 1321 | // the caller's stack pointer. This is true on x86-32/x86-64 at least. |
| 1322 | |
| 1323 | RegisterNumber sp_regnum (m_thread, eRegisterKindGeneric, LLDB_REGNUM_GENERIC_SP1); |
| 1324 | if (sp_regnum.GetAsKind (eRegisterKindLLDB) != LLDB_INVALID_REGNUM(4294967295U) |
| 1325 | && sp_regnum.GetAsKind (eRegisterKindLLDB) == regnum.GetAsKind (eRegisterKindLLDB)) |
| 1326 | { |
| 1327 | // make sure we won't lose precision copying an addr_t (m_cfa) into a uint64_t (.inferred_value) |
| 1328 | assert (sizeof (addr_t) <= sizeof (uint64_t))((sizeof (addr_t) <= sizeof (uint64_t)) ? static_cast<void > (0) : __assert_fail ("sizeof (addr_t) <= sizeof (uint64_t)" , "/tmp/buildd/llvm-toolchain-snapshot-3.7~svn230168/tools/lldb/source/Plugins/Process/Utility/RegisterContextLLDB.cpp" , 1328, __PRETTY_FUNCTION__)); |
| 1329 | regloc.type = UnwindLLDB::RegisterLocation::eRegisterValueInferred; |
| 1330 | regloc.location.inferred_value = m_cfa; |
| 1331 | m_registers[regnum.GetAsKind (eRegisterKindLLDB)] = regloc; |
| 1332 | UnwindLogMsg ("supplying caller's stack pointer %s (%d) value, computed from CFA", |
| 1333 | regnum.GetName(), regnum.GetAsKind (eRegisterKindLLDB)); |
| 1334 | return UnwindLLDB::RegisterSearchResult::eRegisterFound; |
| 1335 | } |
| 1336 | } |
| 1337 | |
| 1338 | ExecutionContext exe_ctx(m_thread.shared_from_this()); |
| 1339 | Process *process = exe_ctx.GetProcessPtr(); |
| 1340 | if (have_unwindplan_regloc == false) |
| 1341 | { |
| 1342 | // If a volatile register is being requested, we don't want to forward the next frame's register contents |
| 1343 | // up the stack -- the register is not retrievable at this frame. |
| 1344 | ABI *abi = process ? process->GetABI().get() : NULL__null; |
| 1345 | if (abi) |
| 1346 | { |
| 1347 | const RegisterInfo *reg_info = GetRegisterInfoAtIndex(regnum.GetAsKind (eRegisterKindLLDB)); |
| 1348 | if (reg_info && abi->RegisterIsVolatile (reg_info)) |
| 1349 | { |
| 1350 | UnwindLogMsg ("did not supply reg location for %s (%d) because it is volatile", |
| 1351 | regnum.GetName(), regnum.GetAsKind (eRegisterKindLLDB)); |
| 1352 | return UnwindLLDB::RegisterSearchResult::eRegisterIsVolatile; |
| 1353 | } |
| 1354 | } |
| 1355 | |
| 1356 | if (IsFrameZero ()) |
| 1357 | { |
| 1358 | // This is frame 0 - we should return the actual live register context value |
| 1359 | lldb_private::UnwindLLDB::RegisterLocation new_regloc; |
| 1360 | new_regloc.type = UnwindLLDB::RegisterLocation::eRegisterInLiveRegisterContext; |
| 1361 | new_regloc.location.register_number = regnum.GetAsKind (eRegisterKindLLDB); |
| 1362 | m_registers[regnum.GetAsKind (eRegisterKindLLDB)] = new_regloc; |
| 1363 | regloc = new_regloc; |
| 1364 | UnwindLogMsg ("supplying caller's register %s (%d) from the live RegisterContext at frame 0", |
| 1365 | regnum.GetName(), regnum.GetAsKind (eRegisterKindLLDB)); |
| 1366 | return UnwindLLDB::RegisterSearchResult::eRegisterFound; |
| 1367 | } |
| 1368 | else |
| 1369 | { |
| 1370 | std::string unwindplan_name (""); |
| 1371 | if (m_full_unwind_plan_sp) |
| 1372 | { |
| 1373 | unwindplan_name += "via '"; |
| 1374 | unwindplan_name += m_full_unwind_plan_sp->GetSourceName().AsCString(); |
| 1375 | unwindplan_name += "'"; |
| 1376 | } |
| 1377 | UnwindLogMsg ("no save location for %s (%d) %s", |
| 1378 | regnum.GetName(), regnum.GetAsKind (eRegisterKindLLDB), |
| 1379 | unwindplan_name.c_str()); |
| 1380 | } |
| 1381 | return UnwindLLDB::RegisterSearchResult::eRegisterNotFound; |
| 1382 | } |
| 1383 | |
| 1384 | // unwindplan_regloc has valid contents about where to retrieve the register |
| 1385 | if (unwindplan_regloc.IsUnspecified()) |
| 1386 | { |
| 1387 | lldb_private::UnwindLLDB::RegisterLocation new_regloc; |
| 1388 | new_regloc.type = UnwindLLDB::RegisterLocation::eRegisterNotSaved; |
| 1389 | m_registers[regnum.GetAsKind (eRegisterKindLLDB)] = new_regloc; |
| 1390 | UnwindLogMsg ("save location for %s (%d) is unspecified, continue searching", |
| 1391 | regnum.GetName(), regnum.GetAsKind (eRegisterKindLLDB)); |
| 1392 | return UnwindLLDB::RegisterSearchResult::eRegisterNotFound; |
| 1393 | } |
| 1394 | |
| 1395 | if (unwindplan_regloc.IsSame()) |
| 1396 | { |
| 1397 | if (IsFrameZero ()) |
| 1398 | { |
| 1399 | UnwindLogMsg ("could not supply caller's %s (%d) location, IsSame", |
| 1400 | regnum.GetName(), regnum.GetAsKind (eRegisterKindLLDB)); |
| 1401 | return UnwindLLDB::RegisterSearchResult::eRegisterNotFound; |
| 1402 | } |
| 1403 | else |
| 1404 | { |
| 1405 | return UnwindLLDB::RegisterSearchResult::eRegisterNotFound; |
| 1406 | } |
| 1407 | } |
| 1408 | |
| 1409 | if (unwindplan_regloc.IsCFAPlusOffset()) |
| 1410 | { |
| 1411 | int offset = unwindplan_regloc.GetOffset(); |
| 1412 | regloc.type = UnwindLLDB::RegisterLocation::eRegisterValueInferred; |
| 1413 | regloc.location.inferred_value = m_cfa + offset; |
| 1414 | m_registers[regnum.GetAsKind (eRegisterKindLLDB)] = regloc; |
| 1415 | UnwindLogMsg ("supplying caller's register %s (%d), value is CFA plus offset %d [value is 0x%" PRIx64"l" "x" "]", |
| 1416 | regnum.GetName(), regnum.GetAsKind (eRegisterKindLLDB), |
| 1417 | offset, regloc.location.inferred_value); |
| 1418 | return UnwindLLDB::RegisterSearchResult::eRegisterFound; |
| 1419 | } |
| 1420 | |
| 1421 | if (unwindplan_regloc.IsAtCFAPlusOffset()) |
| 1422 | { |
| 1423 | int offset = unwindplan_regloc.GetOffset(); |
| 1424 | regloc.type = UnwindLLDB::RegisterLocation::eRegisterSavedAtMemoryLocation; |
| 1425 | regloc.location.target_memory_location = m_cfa + offset; |
| 1426 | m_registers[regnum.GetAsKind (eRegisterKindLLDB)] = regloc; |
| 1427 | UnwindLogMsg ("supplying caller's register %s (%d) from the stack, saved at CFA plus offset %d [saved at 0x%" PRIx64"l" "x" "]", |
| 1428 | regnum.GetName(), regnum.GetAsKind (eRegisterKindLLDB), |
| 1429 | offset, regloc.location.target_memory_location); |
| 1430 | return UnwindLLDB::RegisterSearchResult::eRegisterFound; |
| 1431 | } |
| 1432 | |
| 1433 | if (unwindplan_regloc.IsInOtherRegister()) |
| 1434 | { |
| 1435 | uint32_t unwindplan_regnum = unwindplan_regloc.GetRegisterNumber(); |
| 1436 | RegisterNumber row_regnum (m_thread, unwindplan_registerkind, unwindplan_regnum); |
| 1437 | if (row_regnum.GetAsKind (eRegisterKindLLDB) == LLDB_INVALID_REGNUM(4294967295U)) |
| 1438 | { |
| 1439 | UnwindLogMsg ("could not supply caller's %s (%d) location - was saved in another reg but couldn't convert that regnum", |
| 1440 | regnum.GetName(), regnum.GetAsKind (eRegisterKindLLDB)); |
| 1441 | return UnwindLLDB::RegisterSearchResult::eRegisterNotFound; |
| 1442 | } |
| 1443 | regloc.type = UnwindLLDB::RegisterLocation::eRegisterInRegister; |
| 1444 | regloc.location.register_number = row_regnum.GetAsKind (eRegisterKindLLDB); |
| 1445 | m_registers[regnum.GetAsKind (eRegisterKindLLDB)] = regloc; |
| 1446 | UnwindLogMsg ("supplying caller's register %s (%d), saved in register %s (%d)", |
| 1447 | regnum.GetName(), regnum.GetAsKind (eRegisterKindLLDB), |
| 1448 | row_regnum.GetName(), row_regnum.GetAsKind (eRegisterKindLLDB)); |
| 1449 | return UnwindLLDB::RegisterSearchResult::eRegisterFound; |
| 1450 | } |
| 1451 | |
| 1452 | if (unwindplan_regloc.IsDWARFExpression() || unwindplan_regloc.IsAtDWARFExpression()) |
| 1453 | { |
| 1454 | DataExtractor dwarfdata (unwindplan_regloc.GetDWARFExpressionBytes(), |
| 1455 | unwindplan_regloc.GetDWARFExpressionLength(), |
| 1456 | process->GetByteOrder(), process->GetAddressByteSize()); |
| 1457 | ModuleSP opcode_ctx; |
| 1458 | DWARFExpression dwarfexpr (opcode_ctx, dwarfdata, 0, unwindplan_regloc.GetDWARFExpressionLength()); |
| 1459 | dwarfexpr.SetRegisterKind (unwindplan_registerkind); |
| 1460 | Value result; |
| 1461 | Error error; |
| 1462 | if (dwarfexpr.Evaluate (&exe_ctx, NULL__null, NULL__null, this, 0, NULL__null, result, &error)) |
| 1463 | { |
| 1464 | addr_t val; |
| 1465 | val = result.GetScalar().ULongLong(); |
| 1466 | if (unwindplan_regloc.IsDWARFExpression()) |
| 1467 | { |
| 1468 | regloc.type = UnwindLLDB::RegisterLocation::eRegisterValueInferred; |
| 1469 | regloc.location.inferred_value = val; |
| 1470 | m_registers[regnum.GetAsKind (eRegisterKindLLDB)] = regloc; |
| 1471 | UnwindLogMsg ("supplying caller's register %s (%d) via DWARF expression (IsDWARFExpression)", |
| 1472 | regnum.GetName(), regnum.GetAsKind (eRegisterKindLLDB)); |
| 1473 | return UnwindLLDB::RegisterSearchResult::eRegisterFound; |
| 1474 | } |
| 1475 | else |
| 1476 | { |
| 1477 | regloc.type = UnwindLLDB::RegisterLocation::eRegisterSavedAtMemoryLocation; |
| 1478 | regloc.location.target_memory_location = val; |
| 1479 | m_registers[regnum.GetAsKind (eRegisterKindLLDB)] = regloc; |
| 1480 | UnwindLogMsg ("supplying caller's register %s (%d) via DWARF expression (IsAtDWARFExpression)", |
| 1481 | regnum.GetName(), regnum.GetAsKind (eRegisterKindLLDB)); |
| 1482 | return UnwindLLDB::RegisterSearchResult::eRegisterFound; |
| 1483 | } |
| 1484 | } |
| 1485 | UnwindLogMsg ("tried to use IsDWARFExpression or IsAtDWARFExpression for %s (%d) but failed", |
| 1486 | regnum.GetName(), regnum.GetAsKind (eRegisterKindLLDB)); |
| 1487 | return UnwindLLDB::RegisterSearchResult::eRegisterNotFound; |
| 1488 | } |
| 1489 | |
| 1490 | UnwindLogMsg ("no save location for %s (%d) in this stack frame", |
| 1491 | regnum.GetName(), regnum.GetAsKind (eRegisterKindLLDB)); |
| 1492 | |
| 1493 | // FIXME UnwindPlan::Row types atDWARFExpression and isDWARFExpression are unsupported. |
| 1494 | |
| 1495 | return UnwindLLDB::RegisterSearchResult::eRegisterNotFound; |
| 1496 | } |
| 1497 | |
| 1498 | // TryFallbackUnwindPlan() -- this method is a little tricky. |
| 1499 | // |
| 1500 | // When this is called, the frame above -- the caller frame, the "previous" frame -- |
| 1501 | // is invalid or bad. |
| 1502 | // |
| 1503 | // Instead of stopping the stack walk here, we'll try a different UnwindPlan and see |
| 1504 | // if we can get a valid frame above us. |
| 1505 | // |
| 1506 | // This most often happens when an unwind plan based on assembly instruction inspection |
| 1507 | // is not correct -- mostly with hand-written assembly functions or functions where the |
| 1508 | // stack frame is set up "out of band", e.g. the kernel saved the register context and |
| 1509 | // then called an asynchronous trap handler like _sigtramp. |
| 1510 | // |
| 1511 | // Often in these cases, if we just do a dumb stack walk we'll get past this tricky |
| 1512 | // frame and our usual techniques can continue to be used. |
| 1513 | |
| 1514 | bool |
| 1515 | RegisterContextLLDB::TryFallbackUnwindPlan () |
| 1516 | { |
| 1517 | if (m_fallback_unwind_plan_sp.get() == nullptr) |
| 1518 | return false; |
| 1519 | |
| 1520 | if (m_full_unwind_plan_sp.get() == nullptr) |
| 1521 | return false; |
| 1522 | |
| 1523 | if (m_full_unwind_plan_sp.get() == m_fallback_unwind_plan_sp.get() |
| 1524 | || m_full_unwind_plan_sp->GetSourceName() == m_fallback_unwind_plan_sp->GetSourceName()) |
| 1525 | { |
| 1526 | return false; |
| 1527 | } |
| 1528 | |
| 1529 | // If a compiler generated unwind plan failed, trying the arch default unwindplan |
| 1530 | // isn't going to do any better. |
| 1531 | if (m_full_unwind_plan_sp->GetSourcedFromCompiler() == eLazyBoolYes) |
| 1532 | return false; |
| 1533 | |
| 1534 | |
| 1535 | // Get the caller's pc value and our own CFA value. |
| 1536 | // Swap in the fallback unwind plan, re-fetch the caller's pc value and CFA value. |
| 1537 | // If they're the same, then the fallback unwind plan provides no benefit. |
| 1538 | |
| 1539 | RegisterNumber pc_regnum (m_thread, eRegisterKindGeneric, LLDB_REGNUM_GENERIC_PC0); |
| 1540 | |
| 1541 | addr_t old_caller_pc_value = LLDB_INVALID_ADDRESS(18446744073709551615UL); |
| 1542 | addr_t new_caller_pc_value = LLDB_INVALID_ADDRESS(18446744073709551615UL); |
| 1543 | addr_t old_this_frame_cfa_value = m_cfa; |
| 1544 | UnwindLLDB::RegisterLocation regloc; |
| 1545 | if (SavedLocationForRegister (pc_regnum.GetAsKind (eRegisterKindLLDB), regloc) == UnwindLLDB::RegisterSearchResult::eRegisterFound) |
| 1546 | { |
| 1547 | const RegisterInfo *reg_info = GetRegisterInfoAtIndex(pc_regnum.GetAsKind (eRegisterKindLLDB)); |
| 1548 | if (reg_info) |
| 1549 | { |
| 1550 | RegisterValue reg_value; |
| 1551 | if (ReadRegisterValueFromRegisterLocation (regloc, reg_info, reg_value)) |
| 1552 | { |
| 1553 | old_caller_pc_value = reg_value.GetAsUInt64(); |
| 1554 | } |
| 1555 | } |
| 1556 | } |
| 1557 | |
| 1558 | // This is a tricky wrinkle! If SavedLocationForRegister() detects a really impossible |
| 1559 | // register location for the full unwind plan, it may call ForceSwitchToFallbackUnwindPlan() |
| 1560 | // which in turn replaces the full unwindplan with the fallback... in short, we're done, |
| 1561 | // we're using the fallback UnwindPlan. |
| 1562 | // We checked if m_fallback_unwind_plan_sp was nullptr at the top -- the only way it |
| 1563 | // became nullptr since then is via SavedLocationForRegister(). |
| 1564 | if (m_fallback_unwind_plan_sp.get() == nullptr) |
| 1565 | return true; |
| 1566 | |
| 1567 | |
| 1568 | // Switch the full UnwindPlan to be the fallback UnwindPlan. If we decide this isn't |
| 1569 | // working, we need to restore. |
| 1570 | // We'll also need to save & restore the value of the m_cfa ivar. Save is down below a bit in 'old_cfa'. |
| 1571 | UnwindPlanSP original_full_unwind_plan_sp = m_full_unwind_plan_sp; |
| 1572 | addr_t old_cfa = m_cfa; |
| 1573 | |
| 1574 | m_registers.clear(); |
| 1575 | |
| 1576 | m_full_unwind_plan_sp = m_fallback_unwind_plan_sp; |
| 1577 | |
| 1578 | UnwindPlan::RowSP active_row = m_fallback_unwind_plan_sp->GetRowForFunctionOffset (m_current_offset); |
| 1579 | |
| 1580 | if (active_row && active_row->GetCFARegister() != LLDB_INVALID_REGNUM(4294967295U)) |
| 1581 | { |
| 1582 | addr_t new_cfa; |
| 1583 | if (!ReadCFAValueForRow (m_fallback_unwind_plan_sp->GetRegisterKind(), active_row, new_cfa) |
| 1584 | || new_cfa == 0 || new_cfa == 1 || new_cfa == LLDB_INVALID_ADDRESS(18446744073709551615UL)) |
| 1585 | { |
| 1586 | UnwindLogMsg ("failed to get cfa with fallback unwindplan"); |
| 1587 | m_fallback_unwind_plan_sp.reset(); |
| 1588 | m_full_unwind_plan_sp = original_full_unwind_plan_sp; |
| 1589 | m_cfa = old_cfa; |
| 1590 | return false; |
| 1591 | } |
| 1592 | m_cfa = new_cfa; |
| 1593 | |
| 1594 | if (SavedLocationForRegister (pc_regnum.GetAsKind (eRegisterKindLLDB), regloc) == UnwindLLDB::RegisterSearchResult::eRegisterFound) |
| 1595 | { |
| 1596 | const RegisterInfo *reg_info = GetRegisterInfoAtIndex(pc_regnum.GetAsKind (eRegisterKindLLDB)); |
| 1597 | if (reg_info) |
| 1598 | { |
| 1599 | RegisterValue reg_value; |
| 1600 | if (ReadRegisterValueFromRegisterLocation (regloc, reg_info, reg_value)) |
| 1601 | { |
| 1602 | new_caller_pc_value = reg_value.GetAsUInt64(); |
| 1603 | } |
| 1604 | } |
| 1605 | } |
| 1606 | |
| 1607 | |
| 1608 | if (new_caller_pc_value == LLDB_INVALID_ADDRESS(18446744073709551615UL)) |
| 1609 | { |
| 1610 | UnwindLogMsg ("failed to get a pc value for the caller frame with the fallback unwind plan"); |
| 1611 | m_fallback_unwind_plan_sp.reset(); |
| 1612 | m_full_unwind_plan_sp = original_full_unwind_plan_sp; |
| 1613 | m_cfa = old_cfa; |
| 1614 | return false; |
| 1615 | } |
| 1616 | |
| 1617 | if (old_caller_pc_value != LLDB_INVALID_ADDRESS(18446744073709551615UL)) |
| 1618 | { |
| 1619 | if (old_caller_pc_value == new_caller_pc_value && new_cfa == old_this_frame_cfa_value) |
| 1620 | { |
| 1621 | UnwindLogMsg ("fallback unwind plan got the same values for this frame CFA and caller frame pc, not using"); |
| 1622 | m_fallback_unwind_plan_sp.reset(); |
| 1623 | m_full_unwind_plan_sp = original_full_unwind_plan_sp; |
| 1624 | m_cfa = old_cfa; |
| 1625 | return false; |
| 1626 | } |
| 1627 | } |
| 1628 | |
| 1629 | UnwindLogMsg ("trying to unwind from this function with the UnwindPlan '%s' because UnwindPlan '%s' failed.", |
| 1630 | m_fallback_unwind_plan_sp->GetSourceName().GetCString(), |
| 1631 | original_full_unwind_plan_sp->GetSourceName().GetCString()); |
| 1632 | |
| 1633 | // We've copied the fallback unwind plan into the full - now clear the fallback. |
| 1634 | m_fallback_unwind_plan_sp.reset(); |
| 1635 | } |
| 1636 | |
| 1637 | return true; |
| 1638 | } |
| 1639 | |
| 1640 | bool |
| 1641 | RegisterContextLLDB::ForceSwitchToFallbackUnwindPlan () |
| 1642 | { |
| 1643 | if (m_fallback_unwind_plan_sp.get() == NULL__null) |
| 1644 | return false; |
| 1645 | |
| 1646 | if (m_full_unwind_plan_sp.get() == NULL__null) |
| 1647 | return false; |
| 1648 | |
| 1649 | if (m_full_unwind_plan_sp.get() == m_fallback_unwind_plan_sp.get() |
| 1650 | || m_full_unwind_plan_sp->GetSourceName() == m_fallback_unwind_plan_sp->GetSourceName()) |
| 1651 | { |
| 1652 | return false; |
| 1653 | } |
| 1654 | |
| 1655 | UnwindPlan::RowSP active_row = m_fallback_unwind_plan_sp->GetRowForFunctionOffset (m_current_offset); |
| 1656 | |
| 1657 | if (active_row && active_row->GetCFARegister() != LLDB_INVALID_REGNUM(4294967295U)) |
| 1658 | { |
| 1659 | addr_t new_cfa; |
| 1660 | if (!ReadCFAValueForRow (m_fallback_unwind_plan_sp->GetRegisterKind(), active_row, new_cfa) |
| 1661 | || new_cfa == 0 || new_cfa == 1 || new_cfa == LLDB_INVALID_ADDRESS(18446744073709551615UL)) |
| 1662 | { |
| 1663 | UnwindLogMsg ("failed to get cfa with fallback unwindplan"); |
| 1664 | m_fallback_unwind_plan_sp.reset(); |
| 1665 | return false; |
| 1666 | } |
| 1667 | |
| 1668 | m_full_unwind_plan_sp = m_fallback_unwind_plan_sp; |
| 1669 | m_fallback_unwind_plan_sp.reset(); |
| 1670 | |
| 1671 | m_registers.clear(); |
| 1672 | |
| 1673 | m_cfa = new_cfa; |
| 1674 | |
| 1675 | UnwindLogMsg ("switched unconditionally to the fallback unwindplan %s", m_full_unwind_plan_sp->GetSourceName().GetCString()); |
| 1676 | return true; |
| 1677 | } |
| 1678 | return false; |
| 1679 | } |
| 1680 | |
| 1681 | bool |
| 1682 | RegisterContextLLDB::ReadCFAValueForRow (lldb::RegisterKind row_register_kind, |
| 1683 | const UnwindPlan::RowSP &row, |
| 1684 | addr_t &cfa_value) |
| 1685 | { |
| 1686 | RegisterNumber cfa_reg (m_thread, row_register_kind, row->GetCFARegister()); |
| 1687 | RegisterValue reg_value; |
| 1688 | |
| 1689 | cfa_value = LLDB_INVALID_ADDRESS(18446744073709551615UL); |
| 1690 | addr_t cfa_reg_contents; |
| 1691 | |
| 1692 | if (ReadGPRValue (cfa_reg, cfa_reg_contents)) |
| 1693 | { |
| 1694 | if (row->GetCFAType() == UnwindPlan::Row::CFAIsRegisterDereferenced) |
| 1695 | { |
| 1696 | const RegisterInfo *reg_info = GetRegisterInfoAtIndex (cfa_reg.GetAsKind (eRegisterKindLLDB)); |
| 1697 | RegisterValue reg_value; |
| 1698 | if (reg_info) |
| 1699 | { |
| 1700 | Error error = ReadRegisterValueFromMemory(reg_info, |
| 1701 | cfa_reg_contents, |
| 1702 | reg_info->byte_size, |
| 1703 | reg_value); |
| 1704 | if (error.Success ()) |
| 1705 | { |
| 1706 | cfa_value = reg_value.GetAsUInt64(); |
| 1707 | UnwindLogMsg ("CFA value via dereferencing reg %s (%d): reg has val 0x%" PRIx64"l" "x" ", CFA value is 0x%" PRIx64"l" "x", |
| 1708 | cfa_reg.GetName(), cfa_reg.GetAsKind (eRegisterKindLLDB), |
| 1709 | cfa_reg_contents, cfa_value); |
| 1710 | return true; |
| 1711 | } |
| 1712 | else |
| 1713 | { |
| 1714 | UnwindLogMsg ("Tried to deref reg %s (%d) [0x%" PRIx64"l" "x" "] but memory read failed.", |
| 1715 | cfa_reg.GetName(), cfa_reg.GetAsKind (eRegisterKindLLDB), |
| 1716 | cfa_reg_contents); |
| 1717 | } |
| 1718 | } |
| 1719 | } |
| 1720 | else |
| 1721 | { |
| 1722 | if (cfa_reg_contents == LLDB_INVALID_ADDRESS(18446744073709551615UL) || cfa_reg_contents == 0 || cfa_reg_contents == 1) |
| 1723 | { |
| 1724 | UnwindLogMsg ("Got an invalid CFA register value - reg %s (%d), value 0x%" PRIx64"l" "x", |
| 1725 | cfa_reg.GetName(), cfa_reg.GetAsKind (eRegisterKindLLDB), |
| 1726 | cfa_reg_contents); |
| 1727 | cfa_reg_contents = LLDB_INVALID_ADDRESS(18446744073709551615UL); |
Value stored to 'cfa_reg_contents' is never read | |
| 1728 | return false; |
| 1729 | } |
| 1730 | cfa_value = cfa_reg_contents + row->GetCFAOffset (); |
| 1731 | UnwindLogMsg ("CFA is 0x%" PRIx64"l" "x" ": Register %s (%d) contents are 0x%" PRIx64"l" "x" ", offset is %d", |
| 1732 | cfa_value, |
| 1733 | cfa_reg.GetName(), cfa_reg.GetAsKind (eRegisterKindLLDB), |
| 1734 | cfa_reg_contents, row->GetCFAOffset ()); |
| 1735 | return true; |
| 1736 | } |
| 1737 | } |
| 1738 | return false; |
| 1739 | } |
| 1740 | |
| 1741 | // Retrieve a general purpose register value for THIS frame, as saved by the NEXT frame, i.e. the frame that |
| 1742 | // this frame called. e.g. |
| 1743 | // |
| 1744 | // foo () { } |
| 1745 | // bar () { foo (); } |
| 1746 | // main () { bar (); } |
| 1747 | // |
| 1748 | // stopped in foo() so |
| 1749 | // frame 0 - foo |
| 1750 | // frame 1 - bar |
| 1751 | // frame 2 - main |
| 1752 | // and this RegisterContext is for frame 1 (bar) - if we want to get the pc value for frame 1, we need to ask |
| 1753 | // where frame 0 (the "next" frame) saved that and retrieve the value. |
| 1754 | |
| 1755 | bool |
| 1756 | RegisterContextLLDB::ReadGPRValue (lldb::RegisterKind register_kind, uint32_t regnum, addr_t &value) |
| 1757 | { |
| 1758 | if (!IsValid()) |
| 1759 | return false; |
| 1760 | |
| 1761 | uint32_t lldb_regnum; |
| 1762 | if (register_kind == eRegisterKindLLDB) |
| 1763 | { |
| 1764 | lldb_regnum = regnum; |
| 1765 | } |
| 1766 | else if (!m_thread.GetRegisterContext()->ConvertBetweenRegisterKinds (register_kind, regnum, eRegisterKindLLDB, lldb_regnum)) |
| 1767 | { |
| 1768 | return false; |
| 1769 | } |
| 1770 | |
| 1771 | const RegisterInfo *reg_info = GetRegisterInfoAtIndex(lldb_regnum); |
| 1772 | RegisterValue reg_value; |
| 1773 | // if this is frame 0 (currently executing frame), get the requested reg contents from the actual thread registers |
| 1774 | if (IsFrameZero ()) |
| 1775 | { |
| 1776 | if (m_thread.GetRegisterContext()->ReadRegister (reg_info, reg_value)) |
| 1777 | { |
| 1778 | value = reg_value.GetAsUInt64(); |
| 1779 | return true; |
| 1780 | } |
| 1781 | return false; |
| 1782 | } |
| 1783 | |
| 1784 | bool pc_register = false; |
| 1785 | uint32_t generic_regnum; |
| 1786 | if (register_kind == eRegisterKindGeneric && regnum == LLDB_REGNUM_GENERIC_PC0) |
| 1787 | { |
| 1788 | pc_register = true; |
| 1789 | } |
| 1790 | else if (m_thread.GetRegisterContext()->ConvertBetweenRegisterKinds (register_kind, regnum, eRegisterKindGeneric, generic_regnum) |
| 1791 | && generic_regnum == LLDB_REGNUM_GENERIC_PC0) |
| 1792 | { |
| 1793 | pc_register = true; |
| 1794 | } |
| 1795 | |
| 1796 | lldb_private::UnwindLLDB::RegisterLocation regloc; |
| 1797 | if (!m_parent_unwind.SearchForSavedLocationForRegister (lldb_regnum, regloc, m_frame_number - 1, pc_register)) |
| 1798 | { |
| 1799 | return false; |
| 1800 | } |
| 1801 | if (ReadRegisterValueFromRegisterLocation (regloc, reg_info, reg_value)) |
| 1802 | { |
| 1803 | value = reg_value.GetAsUInt64(); |
| 1804 | return true; |
| 1805 | } |
| 1806 | return false; |
| 1807 | } |
| 1808 | |
| 1809 | bool |
| 1810 | RegisterContextLLDB::ReadGPRValue (const RegisterNumber ®num, addr_t &value) |
| 1811 | { |
| 1812 | return ReadGPRValue (regnum.GetRegisterKind(), regnum.GetRegisterNumber(), value); |
| 1813 | } |
| 1814 | |
| 1815 | // Find the value of a register in THIS frame |
| 1816 | |
| 1817 | bool |
| 1818 | RegisterContextLLDB::ReadRegister (const RegisterInfo *reg_info, RegisterValue &value) |
| 1819 | { |
| 1820 | if (!IsValid()) |
| 1821 | return false; |
| 1822 | |
| 1823 | const uint32_t lldb_regnum = reg_info->kinds[eRegisterKindLLDB]; |
| 1824 | UnwindLogMsgVerbose ("looking for register saved location for reg %d", lldb_regnum); |
| 1825 | |
| 1826 | // If this is the 0th frame, hand this over to the live register context |
| 1827 | if (IsFrameZero ()) |
| 1828 | { |
| 1829 | UnwindLogMsgVerbose ("passing along to the live register context for reg %d", lldb_regnum); |
| 1830 | return m_thread.GetRegisterContext()->ReadRegister (reg_info, value); |
| 1831 | } |
| 1832 | |
| 1833 | lldb_private::UnwindLLDB::RegisterLocation regloc; |
| 1834 | // Find out where the NEXT frame saved THIS frame's register contents |
| 1835 | if (!m_parent_unwind.SearchForSavedLocationForRegister (lldb_regnum, regloc, m_frame_number - 1, false)) |
| 1836 | return false; |
| 1837 | |
| 1838 | return ReadRegisterValueFromRegisterLocation (regloc, reg_info, value); |
| 1839 | } |
| 1840 | |
| 1841 | bool |
| 1842 | RegisterContextLLDB::WriteRegister (const RegisterInfo *reg_info, const RegisterValue &value) |
| 1843 | { |
| 1844 | if (!IsValid()) |
| 1845 | return false; |
| 1846 | |
| 1847 | const uint32_t lldb_regnum = reg_info->kinds[eRegisterKindLLDB]; |
| 1848 | UnwindLogMsgVerbose ("looking for register saved location for reg %d", lldb_regnum); |
| 1849 | |
| 1850 | // If this is the 0th frame, hand this over to the live register context |
| 1851 | if (IsFrameZero ()) |
| 1852 | { |
| 1853 | UnwindLogMsgVerbose ("passing along to the live register context for reg %d", lldb_regnum); |
| 1854 | return m_thread.GetRegisterContext()->WriteRegister (reg_info, value); |
| 1855 | } |
| 1856 | |
| 1857 | lldb_private::UnwindLLDB::RegisterLocation regloc; |
| 1858 | // Find out where the NEXT frame saved THIS frame's register contents |
| 1859 | if (!m_parent_unwind.SearchForSavedLocationForRegister (lldb_regnum, regloc, m_frame_number - 1, false)) |
| 1860 | return false; |
| 1861 | |
| 1862 | return WriteRegisterValueToRegisterLocation (regloc, reg_info, value); |
| 1863 | } |
| 1864 | |
| 1865 | // Don't need to implement this one |
| 1866 | bool |
| 1867 | RegisterContextLLDB::ReadAllRegisterValues (lldb::DataBufferSP &data_sp) |
| 1868 | { |
| 1869 | return false; |
| 1870 | } |
| 1871 | |
| 1872 | // Don't need to implement this one |
| 1873 | bool |
| 1874 | RegisterContextLLDB::WriteAllRegisterValues (const lldb::DataBufferSP& data_sp) |
| 1875 | { |
| 1876 | return false; |
| 1877 | } |
| 1878 | |
| 1879 | // Retrieve the pc value for THIS from |
| 1880 | |
| 1881 | bool |
| 1882 | RegisterContextLLDB::GetCFA (addr_t& cfa) |
| 1883 | { |
| 1884 | if (!IsValid()) |
| 1885 | { |
| 1886 | return false; |
| 1887 | } |
| 1888 | if (m_cfa == LLDB_INVALID_ADDRESS(18446744073709551615UL)) |
| 1889 | { |
| 1890 | return false; |
| 1891 | } |
| 1892 | cfa = m_cfa; |
| 1893 | return true; |
| 1894 | } |
| 1895 | |
| 1896 | |
| 1897 | RegisterContextLLDB::SharedPtr |
| 1898 | RegisterContextLLDB::GetNextFrame () const |
| 1899 | { |
| 1900 | RegisterContextLLDB::SharedPtr regctx; |
| 1901 | if (m_frame_number == 0) |
| 1902 | return regctx; |
| 1903 | return m_parent_unwind.GetRegisterContextForFrameNum (m_frame_number - 1); |
| 1904 | } |
| 1905 | |
| 1906 | RegisterContextLLDB::SharedPtr |
| 1907 | RegisterContextLLDB::GetPrevFrame () const |
| 1908 | { |
| 1909 | RegisterContextLLDB::SharedPtr regctx; |
| 1910 | return m_parent_unwind.GetRegisterContextForFrameNum (m_frame_number + 1); |
| 1911 | } |
| 1912 | |
| 1913 | // Retrieve the address of the start of the function of THIS frame |
| 1914 | |
| 1915 | bool |
| 1916 | RegisterContextLLDB::GetStartPC (addr_t& start_pc) |
| 1917 | { |
| 1918 | if (!IsValid()) |
| 1919 | return false; |
| 1920 | |
| 1921 | if (!m_start_pc.IsValid()) |
| 1922 | { |
| 1923 | return ReadPC (start_pc); |
| 1924 | } |
| 1925 | start_pc = m_start_pc.GetLoadAddress (CalculateTarget().get()); |
| 1926 | return true; |
| 1927 | } |
| 1928 | |
| 1929 | // Retrieve the current pc value for THIS frame, as saved by the NEXT frame. |
| 1930 | |
| 1931 | bool |
| 1932 | RegisterContextLLDB::ReadPC (addr_t& pc) |
| 1933 | { |
| 1934 | if (!IsValid()) |
| 1935 | return false; |
| 1936 | |
| 1937 | bool above_trap_handler = false; |
| 1938 | if (GetNextFrame().get() && GetNextFrame()->IsValid() && GetNextFrame()->IsTrapHandlerFrame()) |
| 1939 | above_trap_handler = true; |
| 1940 | |
| 1941 | if (ReadGPRValue (eRegisterKindGeneric, LLDB_REGNUM_GENERIC_PC0, pc)) |
| 1942 | { |
| 1943 | // A pc value of 0 or 1 is impossible in the middle of the stack -- it indicates the end of a stack walk. |
| 1944 | // On the currently executing frame (or such a frame interrupted asynchronously by sigtramp et al) this may |
| 1945 | // occur if code has jumped through a NULL pointer -- we want to be able to unwind past that frame to help |
| 1946 | // find the bug. |
| 1947 | |
| 1948 | if (m_all_registers_available == false |
| 1949 | && above_trap_handler == false |
| 1950 | && (pc == 0 || pc == 1)) |
| 1951 | { |
| 1952 | return false; |
| 1953 | } |
| 1954 | else |
| 1955 | { |
| 1956 | return true; |
| 1957 | } |
| 1958 | } |
| 1959 | else |
| 1960 | { |
| 1961 | return false; |
| 1962 | } |
| 1963 | } |
| 1964 | |
| 1965 | |
| 1966 | void |
| 1967 | RegisterContextLLDB::UnwindLogMsg (const char *fmt, ...) |
| 1968 | { |
| 1969 | Log *log(GetLogIfAllCategoriesSet (LIBLLDB_LOG_UNWIND(1u << 15))); |
| 1970 | if (log) |
| 1971 | { |
| 1972 | va_list args; |
| 1973 | va_start (args, fmt)__builtin_va_start(args, fmt); |
| 1974 | |
| 1975 | char *logmsg; |
| 1976 | if (vasprintf (&logmsg, fmt, args) == -1 || logmsg == NULL__null) |
| 1977 | { |
| 1978 | if (logmsg) |
| 1979 | free (logmsg); |
| 1980 | va_end (args)__builtin_va_end(args); |
| 1981 | return; |
| 1982 | } |
| 1983 | va_end (args)__builtin_va_end(args); |
| 1984 | |
| 1985 | log->Printf ("%*sth%d/fr%u %s", |
| 1986 | m_frame_number < 100 ? m_frame_number : 100, "", m_thread.GetIndexID(), m_frame_number, |
| 1987 | logmsg); |
| 1988 | free (logmsg); |
| 1989 | } |
| 1990 | } |
| 1991 | |
| 1992 | void |
| 1993 | RegisterContextLLDB::UnwindLogMsgVerbose (const char *fmt, ...) |
| 1994 | { |
| 1995 | Log *log(GetLogIfAllCategoriesSet (LIBLLDB_LOG_UNWIND(1u << 15))); |
| 1996 | if (log && log->GetVerbose()) |
| 1997 | { |
| 1998 | va_list args; |
| 1999 | va_start (args, fmt)__builtin_va_start(args, fmt); |
| 2000 | |
| 2001 | char *logmsg; |
| 2002 | if (vasprintf (&logmsg, fmt, args) == -1 || logmsg == NULL__null) |
| 2003 | { |
| 2004 | if (logmsg) |
| 2005 | free (logmsg); |
| 2006 | va_end (args)__builtin_va_end(args); |
| 2007 | return; |
| 2008 | } |
| 2009 | va_end (args)__builtin_va_end(args); |
| 2010 | |
| 2011 | log->Printf ("%*sth%d/fr%u %s", |
| 2012 | m_frame_number < 100 ? m_frame_number : 100, "", m_thread.GetIndexID(), m_frame_number, |
| 2013 | logmsg); |
| 2014 | free (logmsg); |
| 2015 | } |
| 2016 | } |
| 2017 | |
| 2018 |