1 //===-- NativeProcessLinux.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 "NativeProcessLinux.h" 10 11 #include <cerrno> 12 #include <cstdint> 13 #include <cstring> 14 #include <unistd.h> 15 16 #include <fstream> 17 #include <mutex> 18 #include <optional> 19 #include <sstream> 20 #include <string> 21 #include <unordered_map> 22 23 #include "NativeThreadLinux.h" 24 #include "Plugins/Process/POSIX/ProcessPOSIXLog.h" 25 #include "Plugins/Process/Utility/LinuxProcMaps.h" 26 #include "Procfs.h" 27 #include "lldb/Core/ModuleSpec.h" 28 #include "lldb/Host/Host.h" 29 #include "lldb/Host/HostProcess.h" 30 #include "lldb/Host/ProcessLaunchInfo.h" 31 #include "lldb/Host/PseudoTerminal.h" 32 #include "lldb/Host/ThreadLauncher.h" 33 #include "lldb/Host/common/NativeRegisterContext.h" 34 #include "lldb/Host/linux/Host.h" 35 #include "lldb/Host/linux/Ptrace.h" 36 #include "lldb/Host/linux/Uio.h" 37 #include "lldb/Host/posix/ProcessLauncherPosixFork.h" 38 #include "lldb/Symbol/ObjectFile.h" 39 #include "lldb/Target/Process.h" 40 #include "lldb/Target/Target.h" 41 #include "lldb/Utility/LLDBAssert.h" 42 #include "lldb/Utility/LLDBLog.h" 43 #include "lldb/Utility/State.h" 44 #include "lldb/Utility/Status.h" 45 #include "lldb/Utility/StringExtractor.h" 46 #include "llvm/ADT/ScopeExit.h" 47 #include "llvm/Support/Errno.h" 48 #include "llvm/Support/Error.h" 49 #include "llvm/Support/FileSystem.h" 50 #include "llvm/Support/Threading.h" 51 52 #include <linux/unistd.h> 53 #include <sys/socket.h> 54 #include <sys/syscall.h> 55 #include <sys/types.h> 56 #include <sys/user.h> 57 #include <sys/wait.h> 58 59 #ifdef __aarch64__ 60 #include <asm/hwcap.h> 61 #include <sys/auxv.h> 62 #endif 63 64 // Support hardware breakpoints in case it has not been defined 65 #ifndef TRAP_HWBKPT 66 #define TRAP_HWBKPT 4 67 #endif 68 69 #ifndef HWCAP2_MTE 70 #define HWCAP2_MTE (1 << 18) 71 #endif 72 73 using namespace lldb; 74 using namespace lldb_private; 75 using namespace lldb_private::process_linux; 76 using namespace llvm; 77 78 // Private bits we only need internally. 79 80 static bool ProcessVmReadvSupported() { 81 static bool is_supported; 82 static llvm::once_flag flag; 83 84 llvm::call_once(flag, [] { 85 Log *log = GetLog(POSIXLog::Process); 86 87 uint32_t source = 0x47424742; 88 uint32_t dest = 0; 89 90 struct iovec local, remote; 91 remote.iov_base = &source; 92 local.iov_base = &dest; 93 remote.iov_len = local.iov_len = sizeof source; 94 95 // We shall try if cross-process-memory reads work by attempting to read a 96 // value from our own process. 97 ssize_t res = process_vm_readv(getpid(), &local, 1, &remote, 1, 0); 98 is_supported = (res == sizeof(source) && source == dest); 99 if (is_supported) 100 LLDB_LOG(log, 101 "Detected kernel support for process_vm_readv syscall. " 102 "Fast memory reads enabled."); 103 else 104 LLDB_LOG(log, 105 "syscall process_vm_readv failed (error: {0}). Fast memory " 106 "reads disabled.", 107 llvm::sys::StrError()); 108 }); 109 110 return is_supported; 111 } 112 113 static void MaybeLogLaunchInfo(const ProcessLaunchInfo &info) { 114 Log *log = GetLog(POSIXLog::Process); 115 if (!log) 116 return; 117 118 if (const FileAction *action = info.GetFileActionForFD(STDIN_FILENO)) 119 LLDB_LOG(log, "setting STDIN to '{0}'", action->GetFileSpec()); 120 else 121 LLDB_LOG(log, "leaving STDIN as is"); 122 123 if (const FileAction *action = info.GetFileActionForFD(STDOUT_FILENO)) 124 LLDB_LOG(log, "setting STDOUT to '{0}'", action->GetFileSpec()); 125 else 126 LLDB_LOG(log, "leaving STDOUT as is"); 127 128 if (const FileAction *action = info.GetFileActionForFD(STDERR_FILENO)) 129 LLDB_LOG(log, "setting STDERR to '{0}'", action->GetFileSpec()); 130 else 131 LLDB_LOG(log, "leaving STDERR as is"); 132 133 int i = 0; 134 for (const char **args = info.GetArguments().GetConstArgumentVector(); *args; 135 ++args, ++i) 136 LLDB_LOG(log, "arg {0}: '{1}'", i, *args); 137 } 138 139 static void DisplayBytes(StreamString &s, void *bytes, uint32_t count) { 140 uint8_t *ptr = (uint8_t *)bytes; 141 const uint32_t loop_count = std::min<uint32_t>(DEBUG_PTRACE_MAXBYTES, count); 142 for (uint32_t i = 0; i < loop_count; i++) { 143 s.Printf("[%x]", *ptr); 144 ptr++; 145 } 146 } 147 148 static void PtraceDisplayBytes(int &req, void *data, size_t data_size) { 149 Log *log = GetLog(POSIXLog::Ptrace); 150 if (!log) 151 return; 152 StreamString buf; 153 154 switch (req) { 155 case PTRACE_POKETEXT: { 156 DisplayBytes(buf, &data, 8); 157 LLDB_LOGV(log, "PTRACE_POKETEXT {0}", buf.GetData()); 158 break; 159 } 160 case PTRACE_POKEDATA: { 161 DisplayBytes(buf, &data, 8); 162 LLDB_LOGV(log, "PTRACE_POKEDATA {0}", buf.GetData()); 163 break; 164 } 165 case PTRACE_POKEUSER: { 166 DisplayBytes(buf, &data, 8); 167 LLDB_LOGV(log, "PTRACE_POKEUSER {0}", buf.GetData()); 168 break; 169 } 170 case PTRACE_SETREGS: { 171 DisplayBytes(buf, data, data_size); 172 LLDB_LOGV(log, "PTRACE_SETREGS {0}", buf.GetData()); 173 break; 174 } 175 case PTRACE_SETFPREGS: { 176 DisplayBytes(buf, data, data_size); 177 LLDB_LOGV(log, "PTRACE_SETFPREGS {0}", buf.GetData()); 178 break; 179 } 180 case PTRACE_SETSIGINFO: { 181 DisplayBytes(buf, data, sizeof(siginfo_t)); 182 LLDB_LOGV(log, "PTRACE_SETSIGINFO {0}", buf.GetData()); 183 break; 184 } 185 case PTRACE_SETREGSET: { 186 // Extract iov_base from data, which is a pointer to the struct iovec 187 DisplayBytes(buf, *(void **)data, data_size); 188 LLDB_LOGV(log, "PTRACE_SETREGSET {0}", buf.GetData()); 189 break; 190 } 191 default: {} 192 } 193 } 194 195 static constexpr unsigned k_ptrace_word_size = sizeof(void *); 196 static_assert(sizeof(long) >= k_ptrace_word_size, 197 "Size of long must be larger than ptrace word size"); 198 199 // Simple helper function to ensure flags are enabled on the given file 200 // descriptor. 201 static Status EnsureFDFlags(int fd, int flags) { 202 Status error; 203 204 int status = fcntl(fd, F_GETFL); 205 if (status == -1) { 206 error.SetErrorToErrno(); 207 return error; 208 } 209 210 if (fcntl(fd, F_SETFL, status | flags) == -1) { 211 error.SetErrorToErrno(); 212 return error; 213 } 214 215 return error; 216 } 217 218 static llvm::Error AddPtraceScopeNote(llvm::Error original_error) { 219 Expected<int> ptrace_scope = GetPtraceScope(); 220 if (auto E = ptrace_scope.takeError()) { 221 Log *log = GetLog(POSIXLog::Process); 222 LLDB_LOG(log, "error reading value of ptrace_scope: {0}", E); 223 224 // The original error is probably more interesting than not being able to 225 // read or interpret ptrace_scope. 226 return original_error; 227 } 228 229 // We only have suggestions to provide for 1-3. 230 switch (*ptrace_scope) { 231 case 1: 232 case 2: 233 return llvm::createStringError( 234 std::error_code(errno, std::generic_category()), 235 "The current value of ptrace_scope is %d, which can cause ptrace to " 236 "fail to attach to a running process. To fix this, run:\n" 237 "\tsudo sysctl -w kernel.yama.ptrace_scope=0\n" 238 "For more information, see: " 239 "https://www.kernel.org/doc/Documentation/security/Yama.txt.", 240 *ptrace_scope); 241 case 3: 242 return llvm::createStringError( 243 std::error_code(errno, std::generic_category()), 244 "The current value of ptrace_scope is 3, which will cause ptrace to " 245 "fail to attach to a running process. This value cannot be changed " 246 "without rebooting.\n" 247 "For more information, see: " 248 "https://www.kernel.org/doc/Documentation/security/Yama.txt."); 249 case 0: 250 default: 251 return original_error; 252 } 253 } 254 255 NativeProcessLinux::Manager::Manager(MainLoop &mainloop) 256 : NativeProcessProtocol::Manager(mainloop) { 257 Status status; 258 m_sigchld_handle = mainloop.RegisterSignal( 259 SIGCHLD, [this](MainLoopBase &) { SigchldHandler(); }, status); 260 assert(m_sigchld_handle && status.Success()); 261 } 262 263 llvm::Expected<std::unique_ptr<NativeProcessProtocol>> 264 NativeProcessLinux::Manager::Launch(ProcessLaunchInfo &launch_info, 265 NativeDelegate &native_delegate) { 266 Log *log = GetLog(POSIXLog::Process); 267 268 MaybeLogLaunchInfo(launch_info); 269 270 Status status; 271 ::pid_t pid = ProcessLauncherPosixFork() 272 .LaunchProcess(launch_info, status) 273 .GetProcessId(); 274 LLDB_LOG(log, "pid = {0:x}", pid); 275 if (status.Fail()) { 276 LLDB_LOG(log, "failed to launch process: {0}", status); 277 return status.ToError(); 278 } 279 280 // Wait for the child process to trap on its call to execve. 281 int wstatus = 0; 282 ::pid_t wpid = llvm::sys::RetryAfterSignal(-1, ::waitpid, pid, &wstatus, 0); 283 assert(wpid == pid); 284 UNUSED_IF_ASSERT_DISABLED(wpid); 285 if (!WIFSTOPPED(wstatus)) { 286 LLDB_LOG(log, "Could not sync with inferior process: wstatus={1}", 287 WaitStatus::Decode(wstatus)); 288 return llvm::make_error<StringError>("Could not sync with inferior process", 289 llvm::inconvertibleErrorCode()); 290 } 291 LLDB_LOG(log, "inferior started, now in stopped state"); 292 293 status = SetDefaultPtraceOpts(pid); 294 if (status.Fail()) { 295 LLDB_LOG(log, "failed to set default ptrace options: {0}", status); 296 return status.ToError(); 297 } 298 299 llvm::Expected<ArchSpec> arch_or = 300 NativeRegisterContextLinux::DetermineArchitecture(pid); 301 if (!arch_or) 302 return arch_or.takeError(); 303 304 return std::unique_ptr<NativeProcessLinux>(new NativeProcessLinux( 305 pid, launch_info.GetPTY().ReleasePrimaryFileDescriptor(), native_delegate, 306 *arch_or, *this, {pid})); 307 } 308 309 llvm::Expected<std::unique_ptr<NativeProcessProtocol>> 310 NativeProcessLinux::Manager::Attach( 311 lldb::pid_t pid, NativeProcessProtocol::NativeDelegate &native_delegate) { 312 Log *log = GetLog(POSIXLog::Process); 313 LLDB_LOG(log, "pid = {0:x}", pid); 314 315 auto tids_or = NativeProcessLinux::Attach(pid); 316 if (!tids_or) 317 return tids_or.takeError(); 318 ArrayRef<::pid_t> tids = *tids_or; 319 llvm::Expected<ArchSpec> arch_or = 320 NativeRegisterContextLinux::DetermineArchitecture(tids[0]); 321 if (!arch_or) 322 return arch_or.takeError(); 323 324 return std::unique_ptr<NativeProcessLinux>( 325 new NativeProcessLinux(pid, -1, native_delegate, *arch_or, *this, tids)); 326 } 327 328 NativeProcessLinux::Extension 329 NativeProcessLinux::Manager::GetSupportedExtensions() const { 330 NativeProcessLinux::Extension supported = 331 Extension::multiprocess | Extension::fork | Extension::vfork | 332 Extension::pass_signals | Extension::auxv | Extension::libraries_svr4 | 333 Extension::siginfo_read; 334 335 #ifdef __aarch64__ 336 // At this point we do not have a process so read auxv directly. 337 if ((getauxval(AT_HWCAP2) & HWCAP2_MTE)) 338 supported |= Extension::memory_tagging; 339 #endif 340 341 return supported; 342 } 343 344 static std::optional<std::pair<lldb::pid_t, WaitStatus>> WaitPid() { 345 Log *log = GetLog(POSIXLog::Process); 346 347 int status; 348 ::pid_t wait_pid = llvm::sys::RetryAfterSignal( 349 -1, ::waitpid, -1, &status, __WALL | __WNOTHREAD | WNOHANG); 350 351 if (wait_pid == 0) 352 return std::nullopt; 353 354 if (wait_pid == -1) { 355 Status error(errno, eErrorTypePOSIX); 356 LLDB_LOG(log, "waitpid(-1, &status, _) failed: {1}", error); 357 return std::nullopt; 358 } 359 360 WaitStatus wait_status = WaitStatus::Decode(status); 361 362 LLDB_LOG(log, "waitpid(-1, &status, _) = {0}, status = {1}", wait_pid, 363 wait_status); 364 return std::make_pair(wait_pid, wait_status); 365 } 366 367 void NativeProcessLinux::Manager::SigchldHandler() { 368 Log *log = GetLog(POSIXLog::Process); 369 while (true) { 370 auto wait_result = WaitPid(); 371 if (!wait_result) 372 return; 373 lldb::pid_t pid = wait_result->first; 374 WaitStatus status = wait_result->second; 375 376 // Ask each process whether it wants to handle the event. Each event should 377 // be handled by exactly one process, but thread creation events require 378 // special handling. 379 // Thread creation consists of two events (one on the parent and one on the 380 // child thread) and they can arrive in any order nondeterministically. The 381 // parent event carries the information about the child thread, but not 382 // vice-versa. This means that if the child event arrives first, it may not 383 // be handled by any process (because it doesn't know the thread belongs to 384 // it). 385 bool handled = llvm::any_of(m_processes, [&](NativeProcessLinux *process) { 386 return process->TryHandleWaitStatus(pid, status); 387 }); 388 if (!handled) { 389 if (status.type == WaitStatus::Stop && status.status == SIGSTOP) { 390 // Store the thread creation event for later collection. 391 m_unowned_threads.insert(pid); 392 } else { 393 LLDB_LOG(log, "Ignoring waitpid event {0} for pid {1}", status, pid); 394 } 395 } 396 } 397 } 398 399 void NativeProcessLinux::Manager::CollectThread(::pid_t tid) { 400 Log *log = GetLog(POSIXLog::Process); 401 402 if (m_unowned_threads.erase(tid)) 403 return; // We've encountered this thread already. 404 405 // The TID is not tracked yet, let's wait for it to appear. 406 int status = -1; 407 LLDB_LOG(log, 408 "received clone event for tid {0}. tid not tracked yet, " 409 "waiting for it to appear...", 410 tid); 411 ::pid_t wait_pid = 412 llvm::sys::RetryAfterSignal(-1, ::waitpid, tid, &status, __WALL); 413 414 // It's theoretically possible to get other events if the entire process was 415 // SIGKILLed before we got a chance to check this. In that case, we'll just 416 // clean everything up when we get the process exit event. 417 418 LLDB_LOG(log, 419 "waitpid({0}, &status, __WALL) => {1} (errno: {2}, status = {3})", 420 tid, wait_pid, errno, WaitStatus::Decode(status)); 421 } 422 423 // Public Instance Methods 424 425 NativeProcessLinux::NativeProcessLinux(::pid_t pid, int terminal_fd, 426 NativeDelegate &delegate, 427 const ArchSpec &arch, Manager &manager, 428 llvm::ArrayRef<::pid_t> tids) 429 : NativeProcessELF(pid, terminal_fd, delegate), m_manager(manager), 430 m_arch(arch), m_intel_pt_collector(*this) { 431 manager.AddProcess(*this); 432 if (m_terminal_fd != -1) { 433 Status status = EnsureFDFlags(m_terminal_fd, O_NONBLOCK); 434 assert(status.Success()); 435 } 436 437 for (const auto &tid : tids) { 438 NativeThreadLinux &thread = AddThread(tid, /*resume*/ false); 439 ThreadWasCreated(thread); 440 } 441 442 // Let our process instance know the thread has stopped. 443 SetCurrentThreadID(tids[0]); 444 SetState(StateType::eStateStopped, false); 445 } 446 447 llvm::Expected<std::vector<::pid_t>> NativeProcessLinux::Attach(::pid_t pid) { 448 Log *log = GetLog(POSIXLog::Process); 449 450 Status status; 451 // Use a map to keep track of the threads which we have attached/need to 452 // attach. 453 Host::TidMap tids_to_attach; 454 while (Host::FindProcessThreads(pid, tids_to_attach)) { 455 for (Host::TidMap::iterator it = tids_to_attach.begin(); 456 it != tids_to_attach.end();) { 457 if (it->second == false) { 458 lldb::tid_t tid = it->first; 459 460 // Attach to the requested process. 461 // An attach will cause the thread to stop with a SIGSTOP. 462 if ((status = PtraceWrapper(PTRACE_ATTACH, tid)).Fail()) { 463 // No such thread. The thread may have exited. More error handling 464 // may be needed. 465 if (status.GetError() == ESRCH) { 466 it = tids_to_attach.erase(it); 467 continue; 468 } 469 if (status.GetError() == EPERM) { 470 // Depending on the value of ptrace_scope, we can return a different 471 // error that suggests how to fix it. 472 return AddPtraceScopeNote(status.ToError()); 473 } 474 return status.ToError(); 475 } 476 477 int wpid = 478 llvm::sys::RetryAfterSignal(-1, ::waitpid, tid, nullptr, __WALL); 479 // Need to use __WALL otherwise we receive an error with errno=ECHLD At 480 // this point we should have a thread stopped if waitpid succeeds. 481 if (wpid < 0) { 482 // No such thread. The thread may have exited. More error handling 483 // may be needed. 484 if (errno == ESRCH) { 485 it = tids_to_attach.erase(it); 486 continue; 487 } 488 return llvm::errorCodeToError( 489 std::error_code(errno, std::generic_category())); 490 } 491 492 if ((status = SetDefaultPtraceOpts(tid)).Fail()) 493 return status.ToError(); 494 495 LLDB_LOG(log, "adding tid = {0}", tid); 496 it->second = true; 497 } 498 499 // move the loop forward 500 ++it; 501 } 502 } 503 504 size_t tid_count = tids_to_attach.size(); 505 if (tid_count == 0) 506 return llvm::make_error<StringError>("No such process", 507 llvm::inconvertibleErrorCode()); 508 509 std::vector<::pid_t> tids; 510 tids.reserve(tid_count); 511 for (const auto &p : tids_to_attach) 512 tids.push_back(p.first); 513 return std::move(tids); 514 } 515 516 Status NativeProcessLinux::SetDefaultPtraceOpts(lldb::pid_t pid) { 517 long ptrace_opts = 0; 518 519 // Have the child raise an event on exit. This is used to keep the child in 520 // limbo until it is destroyed. 521 ptrace_opts |= PTRACE_O_TRACEEXIT; 522 523 // Have the tracer trace threads which spawn in the inferior process. 524 ptrace_opts |= PTRACE_O_TRACECLONE; 525 526 // Have the tracer notify us before execve returns (needed to disable legacy 527 // SIGTRAP generation) 528 ptrace_opts |= PTRACE_O_TRACEEXEC; 529 530 // Have the tracer trace forked children. 531 ptrace_opts |= PTRACE_O_TRACEFORK; 532 533 // Have the tracer trace vforks. 534 ptrace_opts |= PTRACE_O_TRACEVFORK; 535 536 // Have the tracer trace vfork-done in order to restore breakpoints after 537 // the child finishes sharing memory. 538 ptrace_opts |= PTRACE_O_TRACEVFORKDONE; 539 540 return PtraceWrapper(PTRACE_SETOPTIONS, pid, nullptr, (void *)ptrace_opts); 541 } 542 543 bool NativeProcessLinux::TryHandleWaitStatus(lldb::pid_t pid, 544 WaitStatus status) { 545 if (pid == GetID() && 546 (status.type == WaitStatus::Exit || status.type == WaitStatus::Signal)) { 547 // The process exited. We're done monitoring. Report to delegate. 548 SetExitStatus(status, true); 549 return true; 550 } 551 if (NativeThreadLinux *thread = GetThreadByID(pid)) { 552 MonitorCallback(*thread, status); 553 return true; 554 } 555 return false; 556 } 557 558 void NativeProcessLinux::MonitorCallback(NativeThreadLinux &thread, 559 WaitStatus status) { 560 Log *log = GetLog(LLDBLog::Process); 561 562 // Certain activities differ based on whether the pid is the tid of the main 563 // thread. 564 const bool is_main_thread = (thread.GetID() == GetID()); 565 566 // Handle when the thread exits. 567 if (status.type == WaitStatus::Exit || status.type == WaitStatus::Signal) { 568 LLDB_LOG(log, 569 "got exit status({0}) , tid = {1} ({2} main thread), process " 570 "state = {3}", 571 status, thread.GetID(), is_main_thread ? "is" : "is not", 572 GetState()); 573 574 // This is a thread that exited. Ensure we're not tracking it anymore. 575 StopTrackingThread(thread); 576 577 assert(!is_main_thread && "Main thread exits handled elsewhere"); 578 return; 579 } 580 581 siginfo_t info; 582 const auto info_err = GetSignalInfo(thread.GetID(), &info); 583 584 // Get details on the signal raised. 585 if (info_err.Success()) { 586 // We have retrieved the signal info. Dispatch appropriately. 587 if (info.si_signo == SIGTRAP) 588 MonitorSIGTRAP(info, thread); 589 else 590 MonitorSignal(info, thread); 591 } else { 592 if (info_err.GetError() == EINVAL) { 593 // This is a group stop reception for this tid. We can reach here if we 594 // reinject SIGSTOP, SIGSTP, SIGTTIN or SIGTTOU into the tracee, 595 // triggering the group-stop mechanism. Normally receiving these would 596 // stop the process, pending a SIGCONT. Simulating this state in a 597 // debugger is hard and is generally not needed (one use case is 598 // debugging background task being managed by a shell). For general use, 599 // it is sufficient to stop the process in a signal-delivery stop which 600 // happens before the group stop. This done by MonitorSignal and works 601 // correctly for all signals. 602 LLDB_LOG(log, 603 "received a group stop for pid {0} tid {1}. Transparent " 604 "handling of group stops not supported, resuming the " 605 "thread.", 606 GetID(), thread.GetID()); 607 ResumeThread(thread, thread.GetState(), LLDB_INVALID_SIGNAL_NUMBER); 608 } else { 609 // ptrace(GETSIGINFO) failed (but not due to group-stop). 610 611 // A return value of ESRCH means the thread/process has died in the mean 612 // time. This can (e.g.) happen when another thread does an exit_group(2) 613 // or the entire process get SIGKILLed. 614 // We can't do anything with this thread anymore, but we keep it around 615 // until we get the WIFEXITED event. 616 617 LLDB_LOG(log, 618 "GetSignalInfo({0}) failed: {1}, status = {2}, main_thread = " 619 "{3}. Expecting WIFEXITED soon.", 620 thread.GetID(), info_err, status, is_main_thread); 621 } 622 } 623 } 624 625 void NativeProcessLinux::MonitorSIGTRAP(const siginfo_t &info, 626 NativeThreadLinux &thread) { 627 Log *log = GetLog(POSIXLog::Process); 628 const bool is_main_thread = (thread.GetID() == GetID()); 629 630 assert(info.si_signo == SIGTRAP && "Unexpected child signal!"); 631 632 switch (info.si_code) { 633 case (SIGTRAP | (PTRACE_EVENT_FORK << 8)): 634 case (SIGTRAP | (PTRACE_EVENT_VFORK << 8)): 635 case (SIGTRAP | (PTRACE_EVENT_CLONE << 8)): { 636 // This can either mean a new thread or a new process spawned via 637 // clone(2) without SIGCHLD or CLONE_VFORK flag. Note that clone(2) 638 // can also cause PTRACE_EVENT_FORK and PTRACE_EVENT_VFORK if one 639 // of these flags are passed. 640 641 unsigned long event_message = 0; 642 if (GetEventMessage(thread.GetID(), &event_message).Fail()) { 643 LLDB_LOG(log, 644 "pid {0} received clone() event but GetEventMessage failed " 645 "so we don't know the new pid/tid", 646 thread.GetID()); 647 ResumeThread(thread, thread.GetState(), LLDB_INVALID_SIGNAL_NUMBER); 648 } else { 649 MonitorClone(thread, event_message, info.si_code >> 8); 650 } 651 652 break; 653 } 654 655 case (SIGTRAP | (PTRACE_EVENT_EXEC << 8)): { 656 LLDB_LOG(log, "received exec event, code = {0}", info.si_code ^ SIGTRAP); 657 658 // Exec clears any pending notifications. 659 m_pending_notification_tid = LLDB_INVALID_THREAD_ID; 660 661 // Remove all but the main thread here. Linux fork creates a new process 662 // which only copies the main thread. 663 LLDB_LOG(log, "exec received, stop tracking all but main thread"); 664 665 llvm::erase_if(m_threads, [&](std::unique_ptr<NativeThreadProtocol> &t) { 666 return t->GetID() != GetID(); 667 }); 668 assert(m_threads.size() == 1); 669 auto *main_thread = static_cast<NativeThreadLinux *>(m_threads[0].get()); 670 671 SetCurrentThreadID(main_thread->GetID()); 672 main_thread->SetStoppedByExec(); 673 674 // Tell coordinator about the "new" (since exec) stopped main thread. 675 ThreadWasCreated(*main_thread); 676 677 // Let our delegate know we have just exec'd. 678 NotifyDidExec(); 679 680 // Let the process know we're stopped. 681 StopRunningThreads(main_thread->GetID()); 682 683 break; 684 } 685 686 case (SIGTRAP | (PTRACE_EVENT_EXIT << 8)): { 687 // The inferior process or one of its threads is about to exit. We don't 688 // want to do anything with the thread so we just resume it. In case we 689 // want to implement "break on thread exit" functionality, we would need to 690 // stop here. 691 692 unsigned long data = 0; 693 if (GetEventMessage(thread.GetID(), &data).Fail()) 694 data = -1; 695 696 LLDB_LOG(log, 697 "received PTRACE_EVENT_EXIT, data = {0:x}, WIFEXITED={1}, " 698 "WIFSIGNALED={2}, pid = {3}, main_thread = {4}", 699 data, WIFEXITED(data), WIFSIGNALED(data), thread.GetID(), 700 is_main_thread); 701 702 703 StateType state = thread.GetState(); 704 if (!StateIsRunningState(state)) { 705 // Due to a kernel bug, we may sometimes get this stop after the inferior 706 // gets a SIGKILL. This confuses our state tracking logic in 707 // ResumeThread(), since normally, we should not be receiving any ptrace 708 // events while the inferior is stopped. This makes sure that the 709 // inferior is resumed and exits normally. 710 state = eStateRunning; 711 } 712 ResumeThread(thread, state, LLDB_INVALID_SIGNAL_NUMBER); 713 714 if (is_main_thread) { 715 // Main thread report the read (WIFEXITED) event only after all threads in 716 // the process exit, so we need to stop tracking it here instead of in 717 // MonitorCallback 718 StopTrackingThread(thread); 719 } 720 721 break; 722 } 723 724 case (SIGTRAP | (PTRACE_EVENT_VFORK_DONE << 8)): { 725 if (bool(m_enabled_extensions & Extension::vfork)) { 726 thread.SetStoppedByVForkDone(); 727 StopRunningThreads(thread.GetID()); 728 } 729 else 730 ResumeThread(thread, thread.GetState(), LLDB_INVALID_SIGNAL_NUMBER); 731 break; 732 } 733 734 case 0: 735 case TRAP_TRACE: // We receive this on single stepping. 736 case TRAP_HWBKPT: // We receive this on watchpoint hit 737 { 738 // If a watchpoint was hit, report it 739 uint32_t wp_index; 740 Status error = thread.GetRegisterContext().GetWatchpointHitIndex( 741 wp_index, (uintptr_t)info.si_addr); 742 if (error.Fail()) 743 LLDB_LOG(log, 744 "received error while checking for watchpoint hits, pid = " 745 "{0}, error = {1}", 746 thread.GetID(), error); 747 if (wp_index != LLDB_INVALID_INDEX32) { 748 MonitorWatchpoint(thread, wp_index); 749 break; 750 } 751 752 // If a breakpoint was hit, report it 753 uint32_t bp_index; 754 error = thread.GetRegisterContext().GetHardwareBreakHitIndex( 755 bp_index, (uintptr_t)info.si_addr); 756 if (error.Fail()) 757 LLDB_LOG(log, "received error while checking for hardware " 758 "breakpoint hits, pid = {0}, error = {1}", 759 thread.GetID(), error); 760 if (bp_index != LLDB_INVALID_INDEX32) { 761 MonitorBreakpoint(thread); 762 break; 763 } 764 765 // Otherwise, report step over 766 MonitorTrace(thread); 767 break; 768 } 769 770 case SI_KERNEL: 771 #if defined __mips__ 772 // For mips there is no special signal for watchpoint So we check for 773 // watchpoint in kernel trap 774 { 775 // If a watchpoint was hit, report it 776 uint32_t wp_index; 777 Status error = thread.GetRegisterContext().GetWatchpointHitIndex( 778 wp_index, LLDB_INVALID_ADDRESS); 779 if (error.Fail()) 780 LLDB_LOG(log, 781 "received error while checking for watchpoint hits, pid = " 782 "{0}, error = {1}", 783 thread.GetID(), error); 784 if (wp_index != LLDB_INVALID_INDEX32) { 785 MonitorWatchpoint(thread, wp_index); 786 break; 787 } 788 } 789 // NO BREAK 790 #endif 791 case TRAP_BRKPT: 792 MonitorBreakpoint(thread); 793 break; 794 795 case SIGTRAP: 796 case (SIGTRAP | 0x80): 797 LLDB_LOG( 798 log, 799 "received unknown SIGTRAP stop event ({0}, pid {1} tid {2}, resuming", 800 info.si_code, GetID(), thread.GetID()); 801 802 // Ignore these signals until we know more about them. 803 ResumeThread(thread, thread.GetState(), LLDB_INVALID_SIGNAL_NUMBER); 804 break; 805 806 default: 807 LLDB_LOG(log, "received unknown SIGTRAP stop event ({0}, pid {1} tid {2}", 808 info.si_code, GetID(), thread.GetID()); 809 MonitorSignal(info, thread); 810 break; 811 } 812 } 813 814 void NativeProcessLinux::MonitorTrace(NativeThreadLinux &thread) { 815 Log *log = GetLog(POSIXLog::Process); 816 LLDB_LOG(log, "received trace event, pid = {0}", thread.GetID()); 817 818 // This thread is currently stopped. 819 thread.SetStoppedByTrace(); 820 821 StopRunningThreads(thread.GetID()); 822 } 823 824 void NativeProcessLinux::MonitorBreakpoint(NativeThreadLinux &thread) { 825 Log *log = GetLog(LLDBLog::Process | LLDBLog::Breakpoints); 826 LLDB_LOG(log, "received breakpoint event, pid = {0}", thread.GetID()); 827 828 // Mark the thread as stopped at breakpoint. 829 thread.SetStoppedByBreakpoint(); 830 FixupBreakpointPCAsNeeded(thread); 831 832 if (m_threads_stepping_with_breakpoint.find(thread.GetID()) != 833 m_threads_stepping_with_breakpoint.end()) 834 thread.SetStoppedByTrace(); 835 836 StopRunningThreads(thread.GetID()); 837 } 838 839 void NativeProcessLinux::MonitorWatchpoint(NativeThreadLinux &thread, 840 uint32_t wp_index) { 841 Log *log = GetLog(LLDBLog::Process | LLDBLog::Watchpoints); 842 LLDB_LOG(log, "received watchpoint event, pid = {0}, wp_index = {1}", 843 thread.GetID(), wp_index); 844 845 // Mark the thread as stopped at watchpoint. The address is at 846 // (lldb::addr_t)info->si_addr if we need it. 847 thread.SetStoppedByWatchpoint(wp_index); 848 849 // We need to tell all other running threads before we notify the delegate 850 // about this stop. 851 StopRunningThreads(thread.GetID()); 852 } 853 854 void NativeProcessLinux::MonitorSignal(const siginfo_t &info, 855 NativeThreadLinux &thread) { 856 const int signo = info.si_signo; 857 const bool is_from_llgs = info.si_pid == getpid(); 858 859 Log *log = GetLog(POSIXLog::Process); 860 861 // POSIX says that process behaviour is undefined after it ignores a SIGFPE, 862 // SIGILL, SIGSEGV, or SIGBUS *unless* that signal was generated by a kill(2) 863 // or raise(3). Similarly for tgkill(2) on Linux. 864 // 865 // IOW, user generated signals never generate what we consider to be a 866 // "crash". 867 // 868 // Similarly, ACK signals generated by this monitor. 869 870 // Handle the signal. 871 LLDB_LOG(log, 872 "received signal {0} ({1}) with code {2}, (siginfo pid = {3}, " 873 "waitpid pid = {4})", 874 Host::GetSignalAsCString(signo), signo, info.si_code, 875 thread.GetID()); 876 877 // Check for thread stop notification. 878 if (is_from_llgs && (info.si_code == SI_TKILL) && (signo == SIGSTOP)) { 879 // This is a tgkill()-based stop. 880 LLDB_LOG(log, "pid {0} tid {1}, thread stopped", GetID(), thread.GetID()); 881 882 // Check that we're not already marked with a stop reason. Note this thread 883 // really shouldn't already be marked as stopped - if we were, that would 884 // imply that the kernel signaled us with the thread stopping which we 885 // handled and marked as stopped, and that, without an intervening resume, 886 // we received another stop. It is more likely that we are missing the 887 // marking of a run state somewhere if we find that the thread was marked 888 // as stopped. 889 const StateType thread_state = thread.GetState(); 890 if (!StateIsStoppedState(thread_state, false)) { 891 // An inferior thread has stopped because of a SIGSTOP we have sent it. 892 // Generally, these are not important stops and we don't want to report 893 // them as they are just used to stop other threads when one thread (the 894 // one with the *real* stop reason) hits a breakpoint (watchpoint, 895 // etc...). However, in the case of an asynchronous Interrupt(), this 896 // *is* the real stop reason, so we leave the signal intact if this is 897 // the thread that was chosen as the triggering thread. 898 if (m_pending_notification_tid != LLDB_INVALID_THREAD_ID) { 899 if (m_pending_notification_tid == thread.GetID()) 900 thread.SetStoppedBySignal(SIGSTOP, &info); 901 else 902 thread.SetStoppedWithNoReason(); 903 904 SetCurrentThreadID(thread.GetID()); 905 SignalIfAllThreadsStopped(); 906 } else { 907 // We can end up here if stop was initiated by LLGS but by this time a 908 // thread stop has occurred - maybe initiated by another event. 909 Status error = ResumeThread(thread, thread.GetState(), 0); 910 if (error.Fail()) 911 LLDB_LOG(log, "failed to resume thread {0}: {1}", thread.GetID(), 912 error); 913 } 914 } else { 915 LLDB_LOG(log, 916 "pid {0} tid {1}, thread was already marked as a stopped " 917 "state (state={2}), leaving stop signal as is", 918 GetID(), thread.GetID(), thread_state); 919 SignalIfAllThreadsStopped(); 920 } 921 922 // Done handling. 923 return; 924 } 925 926 // Check if debugger should stop at this signal or just ignore it and resume 927 // the inferior. 928 if (m_signals_to_ignore.contains(signo)) { 929 ResumeThread(thread, thread.GetState(), signo); 930 return; 931 } 932 933 // This thread is stopped. 934 LLDB_LOG(log, "received signal {0}", Host::GetSignalAsCString(signo)); 935 thread.SetStoppedBySignal(signo, &info); 936 937 // Send a stop to the debugger after we get all other threads to stop. 938 StopRunningThreads(thread.GetID()); 939 } 940 941 bool NativeProcessLinux::MonitorClone(NativeThreadLinux &parent, 942 lldb::pid_t child_pid, int event) { 943 Log *log = GetLog(POSIXLog::Process); 944 LLDB_LOG(log, "parent_tid={0}, child_pid={1}, event={2}", parent.GetID(), 945 child_pid, event); 946 947 m_manager.CollectThread(child_pid); 948 949 switch (event) { 950 case PTRACE_EVENT_CLONE: { 951 // PTRACE_EVENT_CLONE can either mean a new thread or a new process. 952 // Try to grab the new process' PGID to figure out which one it is. 953 // If PGID is the same as the PID, then it's a new process. Otherwise, 954 // it's a thread. 955 auto tgid_ret = getPIDForTID(child_pid); 956 if (tgid_ret != child_pid) { 957 // A new thread should have PGID matching our process' PID. 958 assert(!tgid_ret || *tgid_ret == GetID()); 959 960 NativeThreadLinux &child_thread = AddThread(child_pid, /*resume*/ true); 961 ThreadWasCreated(child_thread); 962 963 // Resume the parent. 964 ResumeThread(parent, parent.GetState(), LLDB_INVALID_SIGNAL_NUMBER); 965 break; 966 } 967 } 968 [[fallthrough]]; 969 case PTRACE_EVENT_FORK: 970 case PTRACE_EVENT_VFORK: { 971 bool is_vfork = event == PTRACE_EVENT_VFORK; 972 std::unique_ptr<NativeProcessLinux> child_process{new NativeProcessLinux( 973 static_cast<::pid_t>(child_pid), m_terminal_fd, m_delegate, m_arch, 974 m_manager, {static_cast<::pid_t>(child_pid)})}; 975 if (!is_vfork) 976 child_process->m_software_breakpoints = m_software_breakpoints; 977 978 Extension expected_ext = is_vfork ? Extension::vfork : Extension::fork; 979 if (bool(m_enabled_extensions & expected_ext)) { 980 m_delegate.NewSubprocess(this, std::move(child_process)); 981 // NB: non-vfork clone() is reported as fork 982 parent.SetStoppedByFork(is_vfork, child_pid); 983 StopRunningThreads(parent.GetID()); 984 } else { 985 child_process->Detach(); 986 ResumeThread(parent, parent.GetState(), LLDB_INVALID_SIGNAL_NUMBER); 987 } 988 break; 989 } 990 default: 991 llvm_unreachable("unknown clone_info.event"); 992 } 993 994 return true; 995 } 996 997 bool NativeProcessLinux::SupportHardwareSingleStepping() const { 998 if (m_arch.IsMIPS() || m_arch.GetMachine() == llvm::Triple::arm || 999 m_arch.GetTriple().isRISCV() || m_arch.GetTriple().isLoongArch()) 1000 return false; 1001 return true; 1002 } 1003 1004 Status NativeProcessLinux::Resume(const ResumeActionList &resume_actions) { 1005 Log *log = GetLog(POSIXLog::Process); 1006 LLDB_LOG(log, "pid {0}", GetID()); 1007 1008 NotifyTracersProcessWillResume(); 1009 1010 bool software_single_step = !SupportHardwareSingleStepping(); 1011 1012 if (software_single_step) { 1013 for (const auto &thread : m_threads) { 1014 assert(thread && "thread list should not contain NULL threads"); 1015 1016 const ResumeAction *const action = 1017 resume_actions.GetActionForThread(thread->GetID(), true); 1018 if (action == nullptr) 1019 continue; 1020 1021 if (action->state == eStateStepping) { 1022 Status error = SetupSoftwareSingleStepping( 1023 static_cast<NativeThreadLinux &>(*thread)); 1024 if (error.Fail()) 1025 return error; 1026 } 1027 } 1028 } 1029 1030 for (const auto &thread : m_threads) { 1031 assert(thread && "thread list should not contain NULL threads"); 1032 1033 const ResumeAction *const action = 1034 resume_actions.GetActionForThread(thread->GetID(), true); 1035 1036 if (action == nullptr) { 1037 LLDB_LOG(log, "no action specified for pid {0} tid {1}", GetID(), 1038 thread->GetID()); 1039 continue; 1040 } 1041 1042 LLDB_LOG(log, "processing resume action state {0} for pid {1} tid {2}", 1043 action->state, GetID(), thread->GetID()); 1044 1045 switch (action->state) { 1046 case eStateRunning: 1047 case eStateStepping: { 1048 // Run the thread, possibly feeding it the signal. 1049 const int signo = action->signal; 1050 Status error = ResumeThread(static_cast<NativeThreadLinux &>(*thread), 1051 action->state, signo); 1052 if (error.Fail()) 1053 return Status("NativeProcessLinux::%s: failed to resume thread " 1054 "for pid %" PRIu64 ", tid %" PRIu64 ", error = %s", 1055 __FUNCTION__, GetID(), thread->GetID(), 1056 error.AsCString()); 1057 1058 break; 1059 } 1060 1061 case eStateSuspended: 1062 case eStateStopped: 1063 break; 1064 1065 default: 1066 return Status("NativeProcessLinux::%s (): unexpected state %s specified " 1067 "for pid %" PRIu64 ", tid %" PRIu64, 1068 __FUNCTION__, StateAsCString(action->state), GetID(), 1069 thread->GetID()); 1070 } 1071 } 1072 1073 return Status(); 1074 } 1075 1076 Status NativeProcessLinux::Halt() { 1077 Status error; 1078 1079 if (kill(GetID(), SIGSTOP) != 0) 1080 error.SetErrorToErrno(); 1081 1082 return error; 1083 } 1084 1085 Status NativeProcessLinux::Detach() { 1086 Status error; 1087 1088 // Tell ptrace to detach from the process. 1089 if (GetID() == LLDB_INVALID_PROCESS_ID) 1090 return error; 1091 1092 // Cancel out any SIGSTOPs we may have sent while stopping the process. 1093 // Otherwise, the process may stop as soon as we detach from it. 1094 kill(GetID(), SIGCONT); 1095 1096 for (const auto &thread : m_threads) { 1097 Status e = Detach(thread->GetID()); 1098 if (e.Fail()) 1099 error = 1100 e; // Save the error, but still attempt to detach from other threads. 1101 } 1102 1103 m_intel_pt_collector.Clear(); 1104 1105 return error; 1106 } 1107 1108 Status NativeProcessLinux::Signal(int signo) { 1109 Status error; 1110 1111 Log *log = GetLog(POSIXLog::Process); 1112 LLDB_LOG(log, "sending signal {0} ({1}) to pid {1}", signo, 1113 Host::GetSignalAsCString(signo), GetID()); 1114 1115 if (kill(GetID(), signo)) 1116 error.SetErrorToErrno(); 1117 1118 return error; 1119 } 1120 1121 Status NativeProcessLinux::Interrupt() { 1122 // Pick a running thread (or if none, a not-dead stopped thread) as the 1123 // chosen thread that will be the stop-reason thread. 1124 Log *log = GetLog(POSIXLog::Process); 1125 1126 NativeThreadProtocol *running_thread = nullptr; 1127 NativeThreadProtocol *stopped_thread = nullptr; 1128 1129 LLDB_LOG(log, "selecting running thread for interrupt target"); 1130 for (const auto &thread : m_threads) { 1131 // If we have a running or stepping thread, we'll call that the target of 1132 // the interrupt. 1133 const auto thread_state = thread->GetState(); 1134 if (thread_state == eStateRunning || thread_state == eStateStepping) { 1135 running_thread = thread.get(); 1136 break; 1137 } else if (!stopped_thread && StateIsStoppedState(thread_state, true)) { 1138 // Remember the first non-dead stopped thread. We'll use that as a 1139 // backup if there are no running threads. 1140 stopped_thread = thread.get(); 1141 } 1142 } 1143 1144 if (!running_thread && !stopped_thread) { 1145 Status error("found no running/stepping or live stopped threads as target " 1146 "for interrupt"); 1147 LLDB_LOG(log, "skipping due to error: {0}", error); 1148 1149 return error; 1150 } 1151 1152 NativeThreadProtocol *deferred_signal_thread = 1153 running_thread ? running_thread : stopped_thread; 1154 1155 LLDB_LOG(log, "pid {0} {1} tid {2} chosen for interrupt target", GetID(), 1156 running_thread ? "running" : "stopped", 1157 deferred_signal_thread->GetID()); 1158 1159 StopRunningThreads(deferred_signal_thread->GetID()); 1160 1161 return Status(); 1162 } 1163 1164 Status NativeProcessLinux::Kill() { 1165 Log *log = GetLog(POSIXLog::Process); 1166 LLDB_LOG(log, "pid {0}", GetID()); 1167 1168 Status error; 1169 1170 switch (m_state) { 1171 case StateType::eStateInvalid: 1172 case StateType::eStateExited: 1173 case StateType::eStateCrashed: 1174 case StateType::eStateDetached: 1175 case StateType::eStateUnloaded: 1176 // Nothing to do - the process is already dead. 1177 LLDB_LOG(log, "ignored for PID {0} due to current state: {1}", GetID(), 1178 m_state); 1179 return error; 1180 1181 case StateType::eStateConnected: 1182 case StateType::eStateAttaching: 1183 case StateType::eStateLaunching: 1184 case StateType::eStateStopped: 1185 case StateType::eStateRunning: 1186 case StateType::eStateStepping: 1187 case StateType::eStateSuspended: 1188 // We can try to kill a process in these states. 1189 break; 1190 } 1191 1192 if (kill(GetID(), SIGKILL) != 0) { 1193 error.SetErrorToErrno(); 1194 return error; 1195 } 1196 1197 return error; 1198 } 1199 1200 Status NativeProcessLinux::GetMemoryRegionInfo(lldb::addr_t load_addr, 1201 MemoryRegionInfo &range_info) { 1202 // FIXME review that the final memory region returned extends to the end of 1203 // the virtual address space, 1204 // with no perms if it is not mapped. 1205 1206 // Use an approach that reads memory regions from /proc/{pid}/maps. Assume 1207 // proc maps entries are in ascending order. 1208 // FIXME assert if we find differently. 1209 1210 if (m_supports_mem_region == LazyBool::eLazyBoolNo) { 1211 // We're done. 1212 return Status("unsupported"); 1213 } 1214 1215 Status error = PopulateMemoryRegionCache(); 1216 if (error.Fail()) { 1217 return error; 1218 } 1219 1220 lldb::addr_t prev_base_address = 0; 1221 1222 // FIXME start by finding the last region that is <= target address using 1223 // binary search. Data is sorted. 1224 // There can be a ton of regions on pthreads apps with lots of threads. 1225 for (auto it = m_mem_region_cache.begin(); it != m_mem_region_cache.end(); 1226 ++it) { 1227 MemoryRegionInfo &proc_entry_info = it->first; 1228 1229 // Sanity check assumption that /proc/{pid}/maps entries are ascending. 1230 assert((proc_entry_info.GetRange().GetRangeBase() >= prev_base_address) && 1231 "descending /proc/pid/maps entries detected, unexpected"); 1232 prev_base_address = proc_entry_info.GetRange().GetRangeBase(); 1233 UNUSED_IF_ASSERT_DISABLED(prev_base_address); 1234 1235 // If the target address comes before this entry, indicate distance to next 1236 // region. 1237 if (load_addr < proc_entry_info.GetRange().GetRangeBase()) { 1238 range_info.GetRange().SetRangeBase(load_addr); 1239 range_info.GetRange().SetByteSize( 1240 proc_entry_info.GetRange().GetRangeBase() - load_addr); 1241 range_info.SetReadable(MemoryRegionInfo::OptionalBool::eNo); 1242 range_info.SetWritable(MemoryRegionInfo::OptionalBool::eNo); 1243 range_info.SetExecutable(MemoryRegionInfo::OptionalBool::eNo); 1244 range_info.SetMapped(MemoryRegionInfo::OptionalBool::eNo); 1245 1246 return error; 1247 } else if (proc_entry_info.GetRange().Contains(load_addr)) { 1248 // The target address is within the memory region we're processing here. 1249 range_info = proc_entry_info; 1250 return error; 1251 } 1252 1253 // The target memory address comes somewhere after the region we just 1254 // parsed. 1255 } 1256 1257 // If we made it here, we didn't find an entry that contained the given 1258 // address. Return the load_addr as start and the amount of bytes betwwen 1259 // load address and the end of the memory as size. 1260 range_info.GetRange().SetRangeBase(load_addr); 1261 range_info.GetRange().SetRangeEnd(LLDB_INVALID_ADDRESS); 1262 range_info.SetReadable(MemoryRegionInfo::OptionalBool::eNo); 1263 range_info.SetWritable(MemoryRegionInfo::OptionalBool::eNo); 1264 range_info.SetExecutable(MemoryRegionInfo::OptionalBool::eNo); 1265 range_info.SetMapped(MemoryRegionInfo::OptionalBool::eNo); 1266 return error; 1267 } 1268 1269 Status NativeProcessLinux::PopulateMemoryRegionCache() { 1270 Log *log = GetLog(POSIXLog::Process); 1271 1272 // If our cache is empty, pull the latest. There should always be at least 1273 // one memory region if memory region handling is supported. 1274 if (!m_mem_region_cache.empty()) { 1275 LLDB_LOG(log, "reusing {0} cached memory region entries", 1276 m_mem_region_cache.size()); 1277 return Status(); 1278 } 1279 1280 Status Result; 1281 LinuxMapCallback callback = [&](llvm::Expected<MemoryRegionInfo> Info) { 1282 if (Info) { 1283 FileSpec file_spec(Info->GetName().GetCString()); 1284 FileSystem::Instance().Resolve(file_spec); 1285 m_mem_region_cache.emplace_back(*Info, file_spec); 1286 return true; 1287 } 1288 1289 Result = Info.takeError(); 1290 m_supports_mem_region = LazyBool::eLazyBoolNo; 1291 LLDB_LOG(log, "failed to parse proc maps: {0}", Result); 1292 return false; 1293 }; 1294 1295 // Linux kernel since 2.6.14 has /proc/{pid}/smaps 1296 // if CONFIG_PROC_PAGE_MONITOR is enabled 1297 auto BufferOrError = getProcFile(GetID(), GetCurrentThreadID(), "smaps"); 1298 if (BufferOrError) 1299 ParseLinuxSMapRegions(BufferOrError.get()->getBuffer(), callback); 1300 else { 1301 BufferOrError = getProcFile(GetID(), GetCurrentThreadID(), "maps"); 1302 if (!BufferOrError) { 1303 m_supports_mem_region = LazyBool::eLazyBoolNo; 1304 return BufferOrError.getError(); 1305 } 1306 1307 ParseLinuxMapRegions(BufferOrError.get()->getBuffer(), callback); 1308 } 1309 1310 if (Result.Fail()) 1311 return Result; 1312 1313 if (m_mem_region_cache.empty()) { 1314 // No entries after attempting to read them. This shouldn't happen if 1315 // /proc/{pid}/maps is supported. Assume we don't support map entries via 1316 // procfs. 1317 m_supports_mem_region = LazyBool::eLazyBoolNo; 1318 LLDB_LOG(log, 1319 "failed to find any procfs maps entries, assuming no support " 1320 "for memory region metadata retrieval"); 1321 return Status("not supported"); 1322 } 1323 1324 LLDB_LOG(log, "read {0} memory region entries from /proc/{1}/maps", 1325 m_mem_region_cache.size(), GetID()); 1326 1327 // We support memory retrieval, remember that. 1328 m_supports_mem_region = LazyBool::eLazyBoolYes; 1329 return Status(); 1330 } 1331 1332 void NativeProcessLinux::DoStopIDBumped(uint32_t newBumpId) { 1333 Log *log = GetLog(POSIXLog::Process); 1334 LLDB_LOG(log, "newBumpId={0}", newBumpId); 1335 LLDB_LOG(log, "clearing {0} entries from memory region cache", 1336 m_mem_region_cache.size()); 1337 m_mem_region_cache.clear(); 1338 } 1339 1340 llvm::Expected<uint64_t> 1341 NativeProcessLinux::Syscall(llvm::ArrayRef<uint64_t> args) { 1342 PopulateMemoryRegionCache(); 1343 auto region_it = llvm::find_if(m_mem_region_cache, [](const auto &pair) { 1344 return pair.first.GetExecutable() == MemoryRegionInfo::eYes && 1345 pair.first.GetShared() != MemoryRegionInfo::eYes; 1346 }); 1347 if (region_it == m_mem_region_cache.end()) 1348 return llvm::createStringError(llvm::inconvertibleErrorCode(), 1349 "No executable memory region found!"); 1350 1351 addr_t exe_addr = region_it->first.GetRange().GetRangeBase(); 1352 1353 NativeThreadLinux &thread = *GetCurrentThread(); 1354 assert(thread.GetState() == eStateStopped); 1355 NativeRegisterContextLinux ®_ctx = thread.GetRegisterContext(); 1356 1357 NativeRegisterContextLinux::SyscallData syscall_data = 1358 *reg_ctx.GetSyscallData(); 1359 1360 WritableDataBufferSP registers_sp; 1361 if (llvm::Error Err = reg_ctx.ReadAllRegisterValues(registers_sp).ToError()) 1362 return std::move(Err); 1363 auto restore_regs = llvm::make_scope_exit( 1364 [&] { reg_ctx.WriteAllRegisterValues(registers_sp); }); 1365 1366 llvm::SmallVector<uint8_t, 8> memory(syscall_data.Insn.size()); 1367 size_t bytes_read; 1368 if (llvm::Error Err = 1369 ReadMemory(exe_addr, memory.data(), memory.size(), bytes_read) 1370 .ToError()) { 1371 return std::move(Err); 1372 } 1373 1374 auto restore_mem = llvm::make_scope_exit( 1375 [&] { WriteMemory(exe_addr, memory.data(), memory.size(), bytes_read); }); 1376 1377 if (llvm::Error Err = reg_ctx.SetPC(exe_addr).ToError()) 1378 return std::move(Err); 1379 1380 for (const auto &zip : llvm::zip_first(args, syscall_data.Args)) { 1381 if (llvm::Error Err = 1382 reg_ctx 1383 .WriteRegisterFromUnsigned(std::get<1>(zip), std::get<0>(zip)) 1384 .ToError()) { 1385 return std::move(Err); 1386 } 1387 } 1388 if (llvm::Error Err = WriteMemory(exe_addr, syscall_data.Insn.data(), 1389 syscall_data.Insn.size(), bytes_read) 1390 .ToError()) 1391 return std::move(Err); 1392 1393 m_mem_region_cache.clear(); 1394 1395 // With software single stepping the syscall insn buffer must also include a 1396 // trap instruction to stop the process. 1397 int req = SupportHardwareSingleStepping() ? PTRACE_SINGLESTEP : PTRACE_CONT; 1398 if (llvm::Error Err = 1399 PtraceWrapper(req, thread.GetID(), nullptr, nullptr).ToError()) 1400 return std::move(Err); 1401 1402 int status; 1403 ::pid_t wait_pid = llvm::sys::RetryAfterSignal(-1, ::waitpid, thread.GetID(), 1404 &status, __WALL); 1405 if (wait_pid == -1) { 1406 return llvm::errorCodeToError( 1407 std::error_code(errno, std::generic_category())); 1408 } 1409 assert((unsigned)wait_pid == thread.GetID()); 1410 1411 uint64_t result = reg_ctx.ReadRegisterAsUnsigned(syscall_data.Result, -ESRCH); 1412 1413 // Values larger than this are actually negative errno numbers. 1414 uint64_t errno_threshold = 1415 (uint64_t(-1) >> (64 - 8 * m_arch.GetAddressByteSize())) - 0x1000; 1416 if (result > errno_threshold) { 1417 return llvm::errorCodeToError( 1418 std::error_code(-result & 0xfff, std::generic_category())); 1419 } 1420 1421 return result; 1422 } 1423 1424 llvm::Expected<addr_t> 1425 NativeProcessLinux::AllocateMemory(size_t size, uint32_t permissions) { 1426 1427 std::optional<NativeRegisterContextLinux::MmapData> mmap_data = 1428 GetCurrentThread()->GetRegisterContext().GetMmapData(); 1429 if (!mmap_data) 1430 return llvm::make_error<UnimplementedError>(); 1431 1432 unsigned prot = PROT_NONE; 1433 assert((permissions & (ePermissionsReadable | ePermissionsWritable | 1434 ePermissionsExecutable)) == permissions && 1435 "Unknown permission!"); 1436 if (permissions & ePermissionsReadable) 1437 prot |= PROT_READ; 1438 if (permissions & ePermissionsWritable) 1439 prot |= PROT_WRITE; 1440 if (permissions & ePermissionsExecutable) 1441 prot |= PROT_EXEC; 1442 1443 llvm::Expected<uint64_t> Result = 1444 Syscall({mmap_data->SysMmap, 0, size, prot, MAP_ANONYMOUS | MAP_PRIVATE, 1445 uint64_t(-1), 0}); 1446 if (Result) 1447 m_allocated_memory.try_emplace(*Result, size); 1448 return Result; 1449 } 1450 1451 llvm::Error NativeProcessLinux::DeallocateMemory(lldb::addr_t addr) { 1452 std::optional<NativeRegisterContextLinux::MmapData> mmap_data = 1453 GetCurrentThread()->GetRegisterContext().GetMmapData(); 1454 if (!mmap_data) 1455 return llvm::make_error<UnimplementedError>(); 1456 1457 auto it = m_allocated_memory.find(addr); 1458 if (it == m_allocated_memory.end()) 1459 return llvm::createStringError(llvm::errc::invalid_argument, 1460 "Memory not allocated by the debugger."); 1461 1462 llvm::Expected<uint64_t> Result = 1463 Syscall({mmap_data->SysMunmap, addr, it->second}); 1464 if (!Result) 1465 return Result.takeError(); 1466 1467 m_allocated_memory.erase(it); 1468 return llvm::Error::success(); 1469 } 1470 1471 Status NativeProcessLinux::ReadMemoryTags(int32_t type, lldb::addr_t addr, 1472 size_t len, 1473 std::vector<uint8_t> &tags) { 1474 llvm::Expected<NativeRegisterContextLinux::MemoryTaggingDetails> details = 1475 GetCurrentThread()->GetRegisterContext().GetMemoryTaggingDetails(type); 1476 if (!details) 1477 return Status(details.takeError()); 1478 1479 // Ignore 0 length read 1480 if (!len) 1481 return Status(); 1482 1483 // lldb will align the range it requests but it is not required to by 1484 // the protocol so we'll do it again just in case. 1485 // Remove tag bits too. Ptrace calls may work regardless but that 1486 // is not a guarantee. 1487 MemoryTagManager::TagRange range(details->manager->RemoveTagBits(addr), len); 1488 range = details->manager->ExpandToGranule(range); 1489 1490 // Allocate enough space for all tags to be read 1491 size_t num_tags = range.GetByteSize() / details->manager->GetGranuleSize(); 1492 tags.resize(num_tags * details->manager->GetTagSizeInBytes()); 1493 1494 struct iovec tags_iovec; 1495 uint8_t *dest = tags.data(); 1496 lldb::addr_t read_addr = range.GetRangeBase(); 1497 1498 // This call can return partial data so loop until we error or 1499 // get all tags back. 1500 while (num_tags) { 1501 tags_iovec.iov_base = dest; 1502 tags_iovec.iov_len = num_tags; 1503 1504 Status error = NativeProcessLinux::PtraceWrapper( 1505 details->ptrace_read_req, GetCurrentThreadID(), 1506 reinterpret_cast<void *>(read_addr), static_cast<void *>(&tags_iovec), 1507 0, nullptr); 1508 1509 if (error.Fail()) { 1510 // Discard partial reads 1511 tags.resize(0); 1512 return error; 1513 } 1514 1515 size_t tags_read = tags_iovec.iov_len; 1516 assert(tags_read && (tags_read <= num_tags)); 1517 1518 dest += tags_read * details->manager->GetTagSizeInBytes(); 1519 read_addr += details->manager->GetGranuleSize() * tags_read; 1520 num_tags -= tags_read; 1521 } 1522 1523 return Status(); 1524 } 1525 1526 Status NativeProcessLinux::WriteMemoryTags(int32_t type, lldb::addr_t addr, 1527 size_t len, 1528 const std::vector<uint8_t> &tags) { 1529 llvm::Expected<NativeRegisterContextLinux::MemoryTaggingDetails> details = 1530 GetCurrentThread()->GetRegisterContext().GetMemoryTaggingDetails(type); 1531 if (!details) 1532 return Status(details.takeError()); 1533 1534 // Ignore 0 length write 1535 if (!len) 1536 return Status(); 1537 1538 // lldb will align the range it requests but it is not required to by 1539 // the protocol so we'll do it again just in case. 1540 // Remove tag bits too. Ptrace calls may work regardless but that 1541 // is not a guarantee. 1542 MemoryTagManager::TagRange range(details->manager->RemoveTagBits(addr), len); 1543 range = details->manager->ExpandToGranule(range); 1544 1545 // Not checking number of tags here, we may repeat them below 1546 llvm::Expected<std::vector<lldb::addr_t>> unpacked_tags_or_err = 1547 details->manager->UnpackTagsData(tags); 1548 if (!unpacked_tags_or_err) 1549 return Status(unpacked_tags_or_err.takeError()); 1550 1551 llvm::Expected<std::vector<lldb::addr_t>> repeated_tags_or_err = 1552 details->manager->RepeatTagsForRange(*unpacked_tags_or_err, range); 1553 if (!repeated_tags_or_err) 1554 return Status(repeated_tags_or_err.takeError()); 1555 1556 // Repack them for ptrace to use 1557 llvm::Expected<std::vector<uint8_t>> final_tag_data = 1558 details->manager->PackTags(*repeated_tags_or_err); 1559 if (!final_tag_data) 1560 return Status(final_tag_data.takeError()); 1561 1562 struct iovec tags_vec; 1563 uint8_t *src = final_tag_data->data(); 1564 lldb::addr_t write_addr = range.GetRangeBase(); 1565 // unpacked tags size because the number of bytes per tag might not be 1 1566 size_t num_tags = repeated_tags_or_err->size(); 1567 1568 // This call can partially write tags, so we loop until we 1569 // error or all tags have been written. 1570 while (num_tags > 0) { 1571 tags_vec.iov_base = src; 1572 tags_vec.iov_len = num_tags; 1573 1574 Status error = NativeProcessLinux::PtraceWrapper( 1575 details->ptrace_write_req, GetCurrentThreadID(), 1576 reinterpret_cast<void *>(write_addr), static_cast<void *>(&tags_vec), 0, 1577 nullptr); 1578 1579 if (error.Fail()) { 1580 // Don't attempt to restore the original values in the case of a partial 1581 // write 1582 return error; 1583 } 1584 1585 size_t tags_written = tags_vec.iov_len; 1586 assert(tags_written && (tags_written <= num_tags)); 1587 1588 src += tags_written * details->manager->GetTagSizeInBytes(); 1589 write_addr += details->manager->GetGranuleSize() * tags_written; 1590 num_tags -= tags_written; 1591 } 1592 1593 return Status(); 1594 } 1595 1596 size_t NativeProcessLinux::UpdateThreads() { 1597 // The NativeProcessLinux monitoring threads are always up to date with 1598 // respect to thread state and they keep the thread list populated properly. 1599 // All this method needs to do is return the thread count. 1600 return m_threads.size(); 1601 } 1602 1603 Status NativeProcessLinux::SetBreakpoint(lldb::addr_t addr, uint32_t size, 1604 bool hardware) { 1605 if (hardware) 1606 return SetHardwareBreakpoint(addr, size); 1607 else 1608 return SetSoftwareBreakpoint(addr, size); 1609 } 1610 1611 Status NativeProcessLinux::RemoveBreakpoint(lldb::addr_t addr, bool hardware) { 1612 if (hardware) 1613 return RemoveHardwareBreakpoint(addr); 1614 else 1615 return NativeProcessProtocol::RemoveBreakpoint(addr); 1616 } 1617 1618 llvm::Expected<llvm::ArrayRef<uint8_t>> 1619 NativeProcessLinux::GetSoftwareBreakpointTrapOpcode(size_t size_hint) { 1620 // The ARM reference recommends the use of 0xe7fddefe and 0xdefe but the 1621 // linux kernel does otherwise. 1622 static const uint8_t g_arm_opcode[] = {0xf0, 0x01, 0xf0, 0xe7}; 1623 static const uint8_t g_thumb_opcode[] = {0x01, 0xde}; 1624 1625 switch (GetArchitecture().GetMachine()) { 1626 case llvm::Triple::arm: 1627 switch (size_hint) { 1628 case 2: 1629 return llvm::ArrayRef(g_thumb_opcode); 1630 case 4: 1631 return llvm::ArrayRef(g_arm_opcode); 1632 default: 1633 return llvm::createStringError(llvm::inconvertibleErrorCode(), 1634 "Unrecognised trap opcode size hint!"); 1635 } 1636 default: 1637 return NativeProcessProtocol::GetSoftwareBreakpointTrapOpcode(size_hint); 1638 } 1639 } 1640 1641 Status NativeProcessLinux::ReadMemory(lldb::addr_t addr, void *buf, size_t size, 1642 size_t &bytes_read) { 1643 if (ProcessVmReadvSupported()) { 1644 // The process_vm_readv path is about 50 times faster than ptrace api. We 1645 // want to use this syscall if it is supported. 1646 1647 struct iovec local_iov, remote_iov; 1648 local_iov.iov_base = buf; 1649 local_iov.iov_len = size; 1650 remote_iov.iov_base = reinterpret_cast<void *>(addr); 1651 remote_iov.iov_len = size; 1652 1653 bytes_read = process_vm_readv(GetCurrentThreadID(), &local_iov, 1, 1654 &remote_iov, 1, 0); 1655 const bool success = bytes_read == size; 1656 1657 Log *log = GetLog(POSIXLog::Process); 1658 LLDB_LOG(log, 1659 "using process_vm_readv to read {0} bytes from inferior " 1660 "address {1:x}: {2}", 1661 size, addr, success ? "Success" : llvm::sys::StrError(errno)); 1662 1663 if (success) 1664 return Status(); 1665 // else the call failed for some reason, let's retry the read using ptrace 1666 // api. 1667 } 1668 1669 unsigned char *dst = static_cast<unsigned char *>(buf); 1670 size_t remainder; 1671 long data; 1672 1673 Log *log = GetLog(POSIXLog::Memory); 1674 LLDB_LOG(log, "addr = {0}, buf = {1}, size = {2}", addr, buf, size); 1675 1676 for (bytes_read = 0; bytes_read < size; bytes_read += remainder) { 1677 Status error = NativeProcessLinux::PtraceWrapper( 1678 PTRACE_PEEKDATA, GetCurrentThreadID(), (void *)addr, nullptr, 0, &data); 1679 if (error.Fail()) 1680 return error; 1681 1682 remainder = size - bytes_read; 1683 remainder = remainder > k_ptrace_word_size ? k_ptrace_word_size : remainder; 1684 1685 // Copy the data into our buffer 1686 memcpy(dst, &data, remainder); 1687 1688 LLDB_LOG(log, "[{0:x}]:{1:x}", addr, data); 1689 addr += k_ptrace_word_size; 1690 dst += k_ptrace_word_size; 1691 } 1692 return Status(); 1693 } 1694 1695 Status NativeProcessLinux::WriteMemory(lldb::addr_t addr, const void *buf, 1696 size_t size, size_t &bytes_written) { 1697 const unsigned char *src = static_cast<const unsigned char *>(buf); 1698 size_t remainder; 1699 Status error; 1700 1701 Log *log = GetLog(POSIXLog::Memory); 1702 LLDB_LOG(log, "addr = {0}, buf = {1}, size = {2}", addr, buf, size); 1703 1704 for (bytes_written = 0; bytes_written < size; bytes_written += remainder) { 1705 remainder = size - bytes_written; 1706 remainder = remainder > k_ptrace_word_size ? k_ptrace_word_size : remainder; 1707 1708 if (remainder == k_ptrace_word_size) { 1709 unsigned long data = 0; 1710 memcpy(&data, src, k_ptrace_word_size); 1711 1712 LLDB_LOG(log, "[{0:x}]:{1:x}", addr, data); 1713 error = NativeProcessLinux::PtraceWrapper( 1714 PTRACE_POKEDATA, GetCurrentThreadID(), (void *)addr, (void *)data); 1715 if (error.Fail()) 1716 return error; 1717 } else { 1718 unsigned char buff[8]; 1719 size_t bytes_read; 1720 error = ReadMemory(addr, buff, k_ptrace_word_size, bytes_read); 1721 if (error.Fail()) 1722 return error; 1723 1724 memcpy(buff, src, remainder); 1725 1726 size_t bytes_written_rec; 1727 error = WriteMemory(addr, buff, k_ptrace_word_size, bytes_written_rec); 1728 if (error.Fail()) 1729 return error; 1730 1731 LLDB_LOG(log, "[{0:x}]:{1:x} ({2:x})", addr, *(const unsigned long *)src, 1732 *(unsigned long *)buff); 1733 } 1734 1735 addr += k_ptrace_word_size; 1736 src += k_ptrace_word_size; 1737 } 1738 return error; 1739 } 1740 1741 Status NativeProcessLinux::GetSignalInfo(lldb::tid_t tid, void *siginfo) const { 1742 return PtraceWrapper(PTRACE_GETSIGINFO, tid, nullptr, siginfo); 1743 } 1744 1745 Status NativeProcessLinux::GetEventMessage(lldb::tid_t tid, 1746 unsigned long *message) { 1747 return PtraceWrapper(PTRACE_GETEVENTMSG, tid, nullptr, message); 1748 } 1749 1750 Status NativeProcessLinux::Detach(lldb::tid_t tid) { 1751 if (tid == LLDB_INVALID_THREAD_ID) 1752 return Status(); 1753 1754 return PtraceWrapper(PTRACE_DETACH, tid); 1755 } 1756 1757 bool NativeProcessLinux::HasThreadNoLock(lldb::tid_t thread_id) { 1758 for (const auto &thread : m_threads) { 1759 assert(thread && "thread list should not contain NULL threads"); 1760 if (thread->GetID() == thread_id) { 1761 // We have this thread. 1762 return true; 1763 } 1764 } 1765 1766 // We don't have this thread. 1767 return false; 1768 } 1769 1770 void NativeProcessLinux::StopTrackingThread(NativeThreadLinux &thread) { 1771 Log *const log = GetLog(POSIXLog::Thread); 1772 lldb::tid_t thread_id = thread.GetID(); 1773 LLDB_LOG(log, "tid: {0}", thread_id); 1774 1775 auto it = llvm::find_if(m_threads, [&](const auto &thread_up) { 1776 return thread_up.get() == &thread; 1777 }); 1778 assert(it != m_threads.end()); 1779 m_threads.erase(it); 1780 1781 NotifyTracersOfThreadDestroyed(thread_id); 1782 SignalIfAllThreadsStopped(); 1783 } 1784 1785 void NativeProcessLinux::NotifyTracersProcessDidStop() { 1786 m_intel_pt_collector.ProcessDidStop(); 1787 } 1788 1789 void NativeProcessLinux::NotifyTracersProcessWillResume() { 1790 m_intel_pt_collector.ProcessWillResume(); 1791 } 1792 1793 Status NativeProcessLinux::NotifyTracersOfNewThread(lldb::tid_t tid) { 1794 Log *log = GetLog(POSIXLog::Thread); 1795 Status error(m_intel_pt_collector.OnThreadCreated(tid)); 1796 if (error.Fail()) 1797 LLDB_LOG(log, "Failed to trace a new thread with intel-pt, tid = {0}. {1}", 1798 tid, error.AsCString()); 1799 return error; 1800 } 1801 1802 Status NativeProcessLinux::NotifyTracersOfThreadDestroyed(lldb::tid_t tid) { 1803 Log *log = GetLog(POSIXLog::Thread); 1804 Status error(m_intel_pt_collector.OnThreadDestroyed(tid)); 1805 if (error.Fail()) 1806 LLDB_LOG(log, 1807 "Failed to stop a destroyed thread with intel-pt, tid = {0}. {1}", 1808 tid, error.AsCString()); 1809 return error; 1810 } 1811 1812 NativeThreadLinux &NativeProcessLinux::AddThread(lldb::tid_t thread_id, 1813 bool resume) { 1814 Log *log = GetLog(POSIXLog::Thread); 1815 LLDB_LOG(log, "pid {0} adding thread with tid {1}", GetID(), thread_id); 1816 1817 assert(!HasThreadNoLock(thread_id) && 1818 "attempted to add a thread by id that already exists"); 1819 1820 // If this is the first thread, save it as the current thread 1821 if (m_threads.empty()) 1822 SetCurrentThreadID(thread_id); 1823 1824 m_threads.push_back(std::make_unique<NativeThreadLinux>(*this, thread_id)); 1825 NativeThreadLinux &thread = 1826 static_cast<NativeThreadLinux &>(*m_threads.back()); 1827 1828 Status tracing_error = NotifyTracersOfNewThread(thread.GetID()); 1829 if (tracing_error.Fail()) { 1830 thread.SetStoppedByProcessorTrace(tracing_error.AsCString()); 1831 StopRunningThreads(thread.GetID()); 1832 } else if (resume) 1833 ResumeThread(thread, eStateRunning, LLDB_INVALID_SIGNAL_NUMBER); 1834 else 1835 thread.SetStoppedBySignal(SIGSTOP); 1836 1837 return thread; 1838 } 1839 1840 Status NativeProcessLinux::GetLoadedModuleFileSpec(const char *module_path, 1841 FileSpec &file_spec) { 1842 Status error = PopulateMemoryRegionCache(); 1843 if (error.Fail()) 1844 return error; 1845 1846 FileSpec module_file_spec(module_path); 1847 FileSystem::Instance().Resolve(module_file_spec); 1848 1849 file_spec.Clear(); 1850 for (const auto &it : m_mem_region_cache) { 1851 if (it.second.GetFilename() == module_file_spec.GetFilename()) { 1852 file_spec = it.second; 1853 return Status(); 1854 } 1855 } 1856 return Status("Module file (%s) not found in /proc/%" PRIu64 "/maps file!", 1857 module_file_spec.GetFilename().AsCString(), GetID()); 1858 } 1859 1860 Status NativeProcessLinux::GetFileLoadAddress(const llvm::StringRef &file_name, 1861 lldb::addr_t &load_addr) { 1862 load_addr = LLDB_INVALID_ADDRESS; 1863 Status error = PopulateMemoryRegionCache(); 1864 if (error.Fail()) 1865 return error; 1866 1867 FileSpec file(file_name); 1868 for (const auto &it : m_mem_region_cache) { 1869 if (it.second == file) { 1870 load_addr = it.first.GetRange().GetRangeBase(); 1871 return Status(); 1872 } 1873 } 1874 return Status("No load address found for specified file."); 1875 } 1876 1877 NativeThreadLinux *NativeProcessLinux::GetThreadByID(lldb::tid_t tid) { 1878 return static_cast<NativeThreadLinux *>( 1879 NativeProcessProtocol::GetThreadByID(tid)); 1880 } 1881 1882 NativeThreadLinux *NativeProcessLinux::GetCurrentThread() { 1883 return static_cast<NativeThreadLinux *>( 1884 NativeProcessProtocol::GetCurrentThread()); 1885 } 1886 1887 Status NativeProcessLinux::ResumeThread(NativeThreadLinux &thread, 1888 lldb::StateType state, int signo) { 1889 Log *const log = GetLog(POSIXLog::Thread); 1890 LLDB_LOG(log, "tid: {0}", thread.GetID()); 1891 1892 // Before we do the resume below, first check if we have a pending stop 1893 // notification that is currently waiting for all threads to stop. This is 1894 // potentially a buggy situation since we're ostensibly waiting for threads 1895 // to stop before we send out the pending notification, and here we are 1896 // resuming one before we send out the pending stop notification. 1897 if (m_pending_notification_tid != LLDB_INVALID_THREAD_ID) { 1898 LLDB_LOG(log, 1899 "about to resume tid {0} per explicit request but we have a " 1900 "pending stop notification (tid {1}) that is actively " 1901 "waiting for this thread to stop. Valid sequence of events?", 1902 thread.GetID(), m_pending_notification_tid); 1903 } 1904 1905 // Request a resume. We expect this to be synchronous and the system to 1906 // reflect it is running after this completes. 1907 switch (state) { 1908 case eStateRunning: { 1909 const auto resume_result = thread.Resume(signo); 1910 if (resume_result.Success()) 1911 SetState(eStateRunning, true); 1912 return resume_result; 1913 } 1914 case eStateStepping: { 1915 const auto step_result = thread.SingleStep(signo); 1916 if (step_result.Success()) 1917 SetState(eStateRunning, true); 1918 return step_result; 1919 } 1920 default: 1921 LLDB_LOG(log, "Unhandled state {0}.", state); 1922 llvm_unreachable("Unhandled state for resume"); 1923 } 1924 } 1925 1926 //===----------------------------------------------------------------------===// 1927 1928 void NativeProcessLinux::StopRunningThreads(const lldb::tid_t triggering_tid) { 1929 Log *const log = GetLog(POSIXLog::Thread); 1930 LLDB_LOG(log, "about to process event: (triggering_tid: {0})", 1931 triggering_tid); 1932 1933 m_pending_notification_tid = triggering_tid; 1934 1935 // Request a stop for all the thread stops that need to be stopped and are 1936 // not already known to be stopped. 1937 for (const auto &thread : m_threads) { 1938 if (StateIsRunningState(thread->GetState())) 1939 static_cast<NativeThreadLinux *>(thread.get())->RequestStop(); 1940 } 1941 1942 SignalIfAllThreadsStopped(); 1943 LLDB_LOG(log, "event processing done"); 1944 } 1945 1946 void NativeProcessLinux::SignalIfAllThreadsStopped() { 1947 if (m_pending_notification_tid == LLDB_INVALID_THREAD_ID) 1948 return; // No pending notification. Nothing to do. 1949 1950 for (const auto &thread_sp : m_threads) { 1951 if (StateIsRunningState(thread_sp->GetState())) 1952 return; // Some threads are still running. Don't signal yet. 1953 } 1954 1955 // We have a pending notification and all threads have stopped. 1956 Log *log = GetLog(LLDBLog::Process | LLDBLog::Breakpoints); 1957 1958 // Clear any temporary breakpoints we used to implement software single 1959 // stepping. 1960 for (const auto &thread_info : m_threads_stepping_with_breakpoint) { 1961 Status error = RemoveBreakpoint(thread_info.second); 1962 if (error.Fail()) 1963 LLDB_LOG(log, "pid = {0} remove stepping breakpoint: {1}", 1964 thread_info.first, error); 1965 } 1966 m_threads_stepping_with_breakpoint.clear(); 1967 1968 // Notify the delegate about the stop 1969 SetCurrentThreadID(m_pending_notification_tid); 1970 SetState(StateType::eStateStopped, true); 1971 m_pending_notification_tid = LLDB_INVALID_THREAD_ID; 1972 } 1973 1974 void NativeProcessLinux::ThreadWasCreated(NativeThreadLinux &thread) { 1975 Log *const log = GetLog(POSIXLog::Thread); 1976 LLDB_LOG(log, "tid: {0}", thread.GetID()); 1977 1978 if (m_pending_notification_tid != LLDB_INVALID_THREAD_ID && 1979 StateIsRunningState(thread.GetState())) { 1980 // We will need to wait for this new thread to stop as well before firing 1981 // the notification. 1982 thread.RequestStop(); 1983 } 1984 } 1985 1986 // Wrapper for ptrace to catch errors and log calls. Note that ptrace sets 1987 // errno on error because -1 can be a valid result (i.e. for PTRACE_PEEK*) 1988 Status NativeProcessLinux::PtraceWrapper(int req, lldb::pid_t pid, void *addr, 1989 void *data, size_t data_size, 1990 long *result) { 1991 Status error; 1992 long int ret; 1993 1994 Log *log = GetLog(POSIXLog::Ptrace); 1995 1996 PtraceDisplayBytes(req, data, data_size); 1997 1998 errno = 0; 1999 if (req == PTRACE_GETREGSET || req == PTRACE_SETREGSET) 2000 ret = ptrace(static_cast<__ptrace_request>(req), static_cast<::pid_t>(pid), 2001 *(unsigned int *)addr, data); 2002 else 2003 ret = ptrace(static_cast<__ptrace_request>(req), static_cast<::pid_t>(pid), 2004 addr, data); 2005 2006 if (ret == -1) 2007 error.SetErrorToErrno(); 2008 2009 if (result) 2010 *result = ret; 2011 2012 LLDB_LOG(log, "ptrace({0}, {1}, {2}, {3}, {4})={5:x}", req, pid, addr, data, 2013 data_size, ret); 2014 2015 PtraceDisplayBytes(req, data, data_size); 2016 2017 if (error.Fail()) 2018 LLDB_LOG(log, "ptrace() failed: {0}", error); 2019 2020 return error; 2021 } 2022 2023 llvm::Expected<TraceSupportedResponse> NativeProcessLinux::TraceSupported() { 2024 if (IntelPTCollector::IsSupported()) 2025 return TraceSupportedResponse{"intel-pt", "Intel Processor Trace"}; 2026 return NativeProcessProtocol::TraceSupported(); 2027 } 2028 2029 Error NativeProcessLinux::TraceStart(StringRef json_request, StringRef type) { 2030 if (type == "intel-pt") { 2031 if (Expected<TraceIntelPTStartRequest> request = 2032 json::parse<TraceIntelPTStartRequest>(json_request, 2033 "TraceIntelPTStartRequest")) { 2034 return m_intel_pt_collector.TraceStart(*request); 2035 } else 2036 return request.takeError(); 2037 } 2038 2039 return NativeProcessProtocol::TraceStart(json_request, type); 2040 } 2041 2042 Error NativeProcessLinux::TraceStop(const TraceStopRequest &request) { 2043 if (request.type == "intel-pt") 2044 return m_intel_pt_collector.TraceStop(request); 2045 return NativeProcessProtocol::TraceStop(request); 2046 } 2047 2048 Expected<json::Value> NativeProcessLinux::TraceGetState(StringRef type) { 2049 if (type == "intel-pt") 2050 return m_intel_pt_collector.GetState(); 2051 return NativeProcessProtocol::TraceGetState(type); 2052 } 2053 2054 Expected<std::vector<uint8_t>> NativeProcessLinux::TraceGetBinaryData( 2055 const TraceGetBinaryDataRequest &request) { 2056 if (request.type == "intel-pt") 2057 return m_intel_pt_collector.GetBinaryData(request); 2058 return NativeProcessProtocol::TraceGetBinaryData(request); 2059 } 2060