1 //===-- ThreadPlanCallFunction.cpp ----------------------------------------===// 2 // 3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4 // See https://llvm.org/LICENSE.txt for license information. 5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6 // 7 //===----------------------------------------------------------------------===// 8 9 #include "lldb/Target/ThreadPlanCallFunction.h" 10 #include "lldb/Breakpoint/Breakpoint.h" 11 #include "lldb/Breakpoint/BreakpointLocation.h" 12 #include "lldb/Core/Address.h" 13 #include "lldb/Core/DumpRegisterValue.h" 14 #include "lldb/Core/Module.h" 15 #include "lldb/Symbol/ObjectFile.h" 16 #include "lldb/Target/ABI.h" 17 #include "lldb/Target/LanguageRuntime.h" 18 #include "lldb/Target/Process.h" 19 #include "lldb/Target/RegisterContext.h" 20 #include "lldb/Target/StopInfo.h" 21 #include "lldb/Target/Target.h" 22 #include "lldb/Target/Thread.h" 23 #include "lldb/Target/ThreadPlanRunToAddress.h" 24 #include "lldb/Utility/Log.h" 25 #include "lldb/Utility/Stream.h" 26 27 #include <memory> 28 29 using namespace lldb; 30 using namespace lldb_private; 31 32 // ThreadPlanCallFunction: Plan to call a single function 33 bool ThreadPlanCallFunction::ConstructorSetup( 34 Thread &thread, ABI *&abi, lldb::addr_t &start_load_addr, 35 lldb::addr_t &function_load_addr) { 36 SetIsMasterPlan(true); 37 SetOkayToDiscard(false); 38 SetPrivate(true); 39 40 ProcessSP process_sp(thread.GetProcess()); 41 if (!process_sp) 42 return false; 43 44 abi = process_sp->GetABI().get(); 45 46 if (!abi) 47 return false; 48 49 Log *log(lldb_private::GetLogIfAnyCategoriesSet(LIBLLDB_LOG_STEP)); 50 51 SetBreakpoints(); 52 53 m_function_sp = thread.GetRegisterContext()->GetSP() - abi->GetRedZoneSize(); 54 // If we can't read memory at the point of the process where we are planning 55 // to put our function, we're not going to get any further... 56 Status error; 57 process_sp->ReadUnsignedIntegerFromMemory(m_function_sp, 4, 0, error); 58 if (!error.Success()) { 59 m_constructor_errors.Printf( 60 "Trying to put the stack in unreadable memory at: 0x%" PRIx64 ".", 61 m_function_sp); 62 LLDB_LOGF(log, "ThreadPlanCallFunction(%p): %s.", static_cast<void *>(this), 63 m_constructor_errors.GetData()); 64 return false; 65 } 66 67 llvm::Expected<Address> start_address = GetTarget().GetEntryPointAddress(); 68 if (!start_address) { 69 m_constructor_errors.Printf( 70 "%s", llvm::toString(start_address.takeError()).c_str()); 71 LLDB_LOGF(log, "ThreadPlanCallFunction(%p): %s.", static_cast<void *>(this), 72 m_constructor_errors.GetData()); 73 return false; 74 } 75 76 m_start_addr = *start_address; 77 start_load_addr = m_start_addr.GetLoadAddress(&GetTarget()); 78 79 // Checkpoint the thread state so we can restore it later. 80 if (log && log->GetVerbose()) 81 ReportRegisterState("About to checkpoint thread before function call. " 82 "Original register state was:"); 83 84 if (!thread.CheckpointThreadState(m_stored_thread_state)) { 85 m_constructor_errors.Printf("Setting up ThreadPlanCallFunction, failed to " 86 "checkpoint thread state."); 87 LLDB_LOGF(log, "ThreadPlanCallFunction(%p): %s.", static_cast<void *>(this), 88 m_constructor_errors.GetData()); 89 return false; 90 } 91 function_load_addr = m_function_addr.GetLoadAddress(&GetTarget()); 92 93 return true; 94 } 95 96 ThreadPlanCallFunction::ThreadPlanCallFunction( 97 Thread &thread, const Address &function, const CompilerType &return_type, 98 llvm::ArrayRef<addr_t> args, const EvaluateExpressionOptions &options) 99 : ThreadPlan(ThreadPlan::eKindCallFunction, "Call function plan", thread, 100 eVoteNoOpinion, eVoteNoOpinion), 101 m_valid(false), m_stop_other_threads(options.GetStopOthers()), 102 m_unwind_on_error(options.DoesUnwindOnError()), 103 m_ignore_breakpoints(options.DoesIgnoreBreakpoints()), 104 m_debug_execution(options.GetDebug()), 105 m_trap_exceptions(options.GetTrapExceptions()), m_function_addr(function), 106 m_function_sp(0), m_takedown_done(false), 107 m_should_clear_objc_exception_bp(false), 108 m_should_clear_cxx_exception_bp(false), 109 m_stop_address(LLDB_INVALID_ADDRESS), m_return_type(return_type) { 110 lldb::addr_t start_load_addr = LLDB_INVALID_ADDRESS; 111 lldb::addr_t function_load_addr = LLDB_INVALID_ADDRESS; 112 ABI *abi = nullptr; 113 114 if (!ConstructorSetup(thread, abi, start_load_addr, function_load_addr)) 115 return; 116 117 if (!abi->PrepareTrivialCall(thread, m_function_sp, function_load_addr, 118 start_load_addr, args)) 119 return; 120 121 ReportRegisterState("Function call was set up. Register state was:"); 122 123 m_valid = true; 124 } 125 126 ThreadPlanCallFunction::ThreadPlanCallFunction( 127 Thread &thread, const Address &function, 128 const EvaluateExpressionOptions &options) 129 : ThreadPlan(ThreadPlan::eKindCallFunction, "Call function plan", thread, 130 eVoteNoOpinion, eVoteNoOpinion), 131 m_valid(false), m_stop_other_threads(options.GetStopOthers()), 132 m_unwind_on_error(options.DoesUnwindOnError()), 133 m_ignore_breakpoints(options.DoesIgnoreBreakpoints()), 134 m_debug_execution(options.GetDebug()), 135 m_trap_exceptions(options.GetTrapExceptions()), m_function_addr(function), 136 m_function_sp(0), m_takedown_done(false), 137 m_should_clear_objc_exception_bp(false), 138 m_should_clear_cxx_exception_bp(false), 139 m_stop_address(LLDB_INVALID_ADDRESS), m_return_type(CompilerType()) {} 140 141 ThreadPlanCallFunction::~ThreadPlanCallFunction() { 142 DoTakedown(PlanSucceeded()); 143 } 144 145 void ThreadPlanCallFunction::ReportRegisterState(const char *message) { 146 Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_STEP)); 147 if (log && log->GetVerbose()) { 148 StreamString strm; 149 RegisterContext *reg_ctx = GetThread().GetRegisterContext().get(); 150 151 log->PutCString(message); 152 153 RegisterValue reg_value; 154 155 for (uint32_t reg_idx = 0, num_registers = reg_ctx->GetRegisterCount(); 156 reg_idx < num_registers; ++reg_idx) { 157 const RegisterInfo *reg_info = reg_ctx->GetRegisterInfoAtIndex(reg_idx); 158 if (reg_ctx->ReadRegister(reg_info, reg_value)) { 159 DumpRegisterValue(reg_value, &strm, reg_info, true, false, 160 eFormatDefault); 161 strm.EOL(); 162 } 163 } 164 log->PutString(strm.GetString()); 165 } 166 } 167 168 void ThreadPlanCallFunction::DoTakedown(bool success) { 169 Log *log(lldb_private::GetLogIfAnyCategoriesSet(LIBLLDB_LOG_STEP)); 170 171 if (!m_valid) { 172 // Don't call DoTakedown if we were never valid to begin with. 173 LLDB_LOGF(log, 174 "ThreadPlanCallFunction(%p): Log called on " 175 "ThreadPlanCallFunction that was never valid.", 176 static_cast<void *>(this)); 177 return; 178 } 179 180 if (!m_takedown_done) { 181 Thread &thread = GetThread(); 182 if (success) { 183 SetReturnValue(); 184 } 185 LLDB_LOGF(log, 186 "ThreadPlanCallFunction(%p): DoTakedown called for thread " 187 "0x%4.4" PRIx64 ", m_valid: %d complete: %d.\n", 188 static_cast<void *>(this), m_tid, m_valid, IsPlanComplete()); 189 m_takedown_done = true; 190 m_stop_address = 191 thread.GetStackFrameAtIndex(0)->GetRegisterContext()->GetPC(); 192 m_real_stop_info_sp = GetPrivateStopInfo(); 193 if (!thread.RestoreRegisterStateFromCheckpoint(m_stored_thread_state)) { 194 LLDB_LOGF(log, 195 "ThreadPlanCallFunction(%p): DoTakedown failed to restore " 196 "register state", 197 static_cast<void *>(this)); 198 } 199 SetPlanComplete(success); 200 ClearBreakpoints(); 201 if (log && log->GetVerbose()) 202 ReportRegisterState("Restoring thread state after function call. " 203 "Restored register state:"); 204 } else { 205 LLDB_LOGF(log, 206 "ThreadPlanCallFunction(%p): DoTakedown called as no-op for " 207 "thread 0x%4.4" PRIx64 ", m_valid: %d complete: %d.\n", 208 static_cast<void *>(this), m_tid, m_valid, IsPlanComplete()); 209 } 210 } 211 212 void ThreadPlanCallFunction::WillPop() { DoTakedown(PlanSucceeded()); } 213 214 void ThreadPlanCallFunction::GetDescription(Stream *s, DescriptionLevel level) { 215 if (level == eDescriptionLevelBrief) { 216 s->Printf("Function call thread plan"); 217 } else { 218 s->Printf("Thread plan to call 0x%" PRIx64, 219 m_function_addr.GetLoadAddress(&GetTarget())); 220 } 221 } 222 223 bool ThreadPlanCallFunction::ValidatePlan(Stream *error) { 224 if (!m_valid) { 225 if (error) { 226 if (m_constructor_errors.GetSize() > 0) 227 error->PutCString(m_constructor_errors.GetString()); 228 else 229 error->PutCString("Unknown error"); 230 } 231 return false; 232 } 233 234 return true; 235 } 236 237 Vote ThreadPlanCallFunction::ShouldReportStop(Event *event_ptr) { 238 if (m_takedown_done || IsPlanComplete()) 239 return eVoteYes; 240 else 241 return ThreadPlan::ShouldReportStop(event_ptr); 242 } 243 244 bool ThreadPlanCallFunction::DoPlanExplainsStop(Event *event_ptr) { 245 Log *log(lldb_private::GetLogIfAnyCategoriesSet(LIBLLDB_LOG_STEP | 246 LIBLLDB_LOG_PROCESS)); 247 m_real_stop_info_sp = GetPrivateStopInfo(); 248 249 // If our subplan knows why we stopped, even if it's done (which would 250 // forward the question to us) we answer yes. 251 if (m_subplan_sp && m_subplan_sp->PlanExplainsStop(event_ptr)) { 252 SetPlanComplete(); 253 return true; 254 } 255 256 // Check if the breakpoint is one of ours. 257 258 StopReason stop_reason; 259 if (!m_real_stop_info_sp) 260 stop_reason = eStopReasonNone; 261 else 262 stop_reason = m_real_stop_info_sp->GetStopReason(); 263 LLDB_LOG(log, 264 "ThreadPlanCallFunction::PlanExplainsStop: Got stop reason - {0}.", 265 Thread::StopReasonAsString(stop_reason)); 266 267 if (stop_reason == eStopReasonBreakpoint && BreakpointsExplainStop()) 268 return true; 269 270 // One more quirk here. If this event was from Halt interrupting the target, 271 // then we should not consider ourselves complete. Return true to 272 // acknowledge the stop. 273 if (Process::ProcessEventData::GetInterruptedFromEvent(event_ptr)) { 274 LLDB_LOGF(log, "ThreadPlanCallFunction::PlanExplainsStop: The event is an " 275 "Interrupt, returning true."); 276 return true; 277 } 278 // We control breakpoints separately from other "stop reasons." So first, 279 // check the case where we stopped for an internal breakpoint, in that case, 280 // continue on. If it is not an internal breakpoint, consult 281 // m_ignore_breakpoints. 282 283 if (stop_reason == eStopReasonBreakpoint) { 284 uint64_t break_site_id = m_real_stop_info_sp->GetValue(); 285 BreakpointSiteSP bp_site_sp; 286 bp_site_sp = m_process.GetBreakpointSiteList().FindByID(break_site_id); 287 if (bp_site_sp) { 288 uint32_t num_owners = bp_site_sp->GetNumberOfOwners(); 289 bool is_internal = true; 290 for (uint32_t i = 0; i < num_owners; i++) { 291 Breakpoint &bp = bp_site_sp->GetOwnerAtIndex(i)->GetBreakpoint(); 292 LLDB_LOGF(log, 293 "ThreadPlanCallFunction::PlanExplainsStop: hit " 294 "breakpoint %d while calling function", 295 bp.GetID()); 296 297 if (!bp.IsInternal()) { 298 is_internal = false; 299 break; 300 } 301 } 302 if (is_internal) { 303 LLDB_LOGF(log, "ThreadPlanCallFunction::PlanExplainsStop hit an " 304 "internal breakpoint, not stopping."); 305 return false; 306 } 307 } 308 309 if (m_ignore_breakpoints) { 310 LLDB_LOGF(log, 311 "ThreadPlanCallFunction::PlanExplainsStop: we are ignoring " 312 "breakpoints, overriding breakpoint stop info ShouldStop, " 313 "returning true"); 314 m_real_stop_info_sp->OverrideShouldStop(false); 315 return true; 316 } else { 317 LLDB_LOGF(log, "ThreadPlanCallFunction::PlanExplainsStop: we are not " 318 "ignoring breakpoints, overriding breakpoint stop info " 319 "ShouldStop, returning true"); 320 m_real_stop_info_sp->OverrideShouldStop(true); 321 return false; 322 } 323 } else if (!m_unwind_on_error) { 324 // If we don't want to discard this plan, than any stop we don't understand 325 // should be propagated up the stack. 326 return false; 327 } else { 328 // If the subplan is running, any crashes are attributable to us. If we 329 // want to discard the plan, then we say we explain the stop but if we are 330 // going to be discarded, let whoever is above us explain the stop. But 331 // don't discard the plan if the stop would restart itself (for instance if 332 // it is a signal that is set not to stop. Check that here first. We just 333 // say we explain the stop but aren't done and everything will continue on 334 // from there. 335 336 if (m_real_stop_info_sp && 337 m_real_stop_info_sp->ShouldStopSynchronous(event_ptr)) { 338 SetPlanComplete(false); 339 return m_subplan_sp ? m_unwind_on_error : false; 340 } else 341 return true; 342 } 343 } 344 345 bool ThreadPlanCallFunction::ShouldStop(Event *event_ptr) { 346 // We do some computation in DoPlanExplainsStop that may or may not set the 347 // plan as complete. We need to do that here to make sure our state is 348 // correct. 349 DoPlanExplainsStop(event_ptr); 350 351 if (IsPlanComplete()) { 352 ReportRegisterState("Function completed. Register state was:"); 353 return true; 354 } else { 355 return false; 356 } 357 } 358 359 bool ThreadPlanCallFunction::StopOthers() { return m_stop_other_threads; } 360 361 StateType ThreadPlanCallFunction::GetPlanRunState() { return eStateRunning; } 362 363 void ThreadPlanCallFunction::DidPush() { 364 //#define SINGLE_STEP_EXPRESSIONS 365 366 // Now set the thread state to "no reason" so we don't run with whatever 367 // signal was outstanding... Wait till the plan is pushed so we aren't 368 // changing the stop info till we're about to run. 369 370 GetThread().SetStopInfoToNothing(); 371 372 #ifndef SINGLE_STEP_EXPRESSIONS 373 Thread &thread = GetThread(); 374 m_subplan_sp = std::make_shared<ThreadPlanRunToAddress>(thread, m_start_addr, 375 m_stop_other_threads); 376 377 thread.QueueThreadPlan(m_subplan_sp, false); 378 m_subplan_sp->SetPrivate(true); 379 #endif 380 } 381 382 bool ThreadPlanCallFunction::WillStop() { return true; } 383 384 bool ThreadPlanCallFunction::MischiefManaged() { 385 Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_STEP)); 386 387 if (IsPlanComplete()) { 388 LLDB_LOGF(log, "ThreadPlanCallFunction(%p): Completed call function plan.", 389 static_cast<void *>(this)); 390 391 ThreadPlan::MischiefManaged(); 392 return true; 393 } else { 394 return false; 395 } 396 } 397 398 void ThreadPlanCallFunction::SetBreakpoints() { 399 if (m_trap_exceptions) { 400 m_cxx_language_runtime = 401 m_process.GetLanguageRuntime(eLanguageTypeC_plus_plus); 402 m_objc_language_runtime = m_process.GetLanguageRuntime(eLanguageTypeObjC); 403 404 if (m_cxx_language_runtime) { 405 m_should_clear_cxx_exception_bp = 406 !m_cxx_language_runtime->ExceptionBreakpointsAreSet(); 407 m_cxx_language_runtime->SetExceptionBreakpoints(); 408 } 409 if (m_objc_language_runtime) { 410 m_should_clear_objc_exception_bp = 411 !m_objc_language_runtime->ExceptionBreakpointsAreSet(); 412 m_objc_language_runtime->SetExceptionBreakpoints(); 413 } 414 } 415 } 416 417 void ThreadPlanCallFunction::ClearBreakpoints() { 418 if (m_trap_exceptions) { 419 if (m_cxx_language_runtime && m_should_clear_cxx_exception_bp) 420 m_cxx_language_runtime->ClearExceptionBreakpoints(); 421 if (m_objc_language_runtime && m_should_clear_objc_exception_bp) 422 m_objc_language_runtime->ClearExceptionBreakpoints(); 423 } 424 } 425 426 bool ThreadPlanCallFunction::BreakpointsExplainStop() { 427 StopInfoSP stop_info_sp = GetPrivateStopInfo(); 428 429 if (m_trap_exceptions) { 430 if ((m_cxx_language_runtime && 431 m_cxx_language_runtime->ExceptionBreakpointsExplainStop( 432 stop_info_sp)) || 433 (m_objc_language_runtime && 434 m_objc_language_runtime->ExceptionBreakpointsExplainStop( 435 stop_info_sp))) { 436 Log *log(lldb_private::GetLogIfAnyCategoriesSet(LIBLLDB_LOG_STEP)); 437 LLDB_LOGF(log, "ThreadPlanCallFunction::BreakpointsExplainStop - Hit an " 438 "exception breakpoint, setting plan complete."); 439 440 SetPlanComplete(false); 441 442 // If the user has set the ObjC language breakpoint, it would normally 443 // get priority over our internal catcher breakpoint, but in this case we 444 // can't let that happen, so force the ShouldStop here. 445 stop_info_sp->OverrideShouldStop(true); 446 return true; 447 } 448 } 449 450 return false; 451 } 452 453 void ThreadPlanCallFunction::SetStopOthers(bool new_value) { 454 m_subplan_sp->SetStopOthers(new_value); 455 } 456 457 bool ThreadPlanCallFunction::RestoreThreadState() { 458 return GetThread().RestoreThreadStateFromCheckpoint(m_stored_thread_state); 459 } 460 461 void ThreadPlanCallFunction::SetReturnValue() { 462 const ABI *abi = m_process.GetABI().get(); 463 if (abi && m_return_type.IsValid()) { 464 const bool persistent = false; 465 m_return_valobj_sp = 466 abi->GetReturnValueObject(GetThread(), m_return_type, persistent); 467 } 468 } 469