xref: /llvm-project/lldb/source/Plugins/Process/Linux/NativeProcessLinux.cpp (revision 3b426a8951caa543b65f20ff265353fd79f436e5)
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 = Status::FromErrno();
207     return error;
208   }
209 
210   if (fcntl(fd, F_SETFL, status | flags) == -1) {
211     error = Status::FromErrno();
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::FromErrorStringWithFormat(
1054             "NativeProcessLinux::%s: failed to resume thread "
1055             "for pid %" PRIu64 ", tid %" PRIu64 ", error = %s",
1056             __FUNCTION__, GetID(), thread->GetID(), error.AsCString());
1057 
1058       break;
1059     }
1060 
1061     case eStateSuspended:
1062     case eStateStopped:
1063       break;
1064 
1065     default:
1066       return Status::FromErrorStringWithFormat(
1067           "NativeProcessLinux::%s (): unexpected state %s specified "
1068           "for pid %" PRIu64 ", tid %" PRIu64,
1069           __FUNCTION__, StateAsCString(action->state), GetID(),
1070           thread->GetID());
1071     }
1072   }
1073 
1074   return Status();
1075 }
1076 
1077 Status NativeProcessLinux::Halt() {
1078   Status error;
1079 
1080   if (kill(GetID(), SIGSTOP) != 0)
1081     error = Status::FromErrno();
1082 
1083   return error;
1084 }
1085 
1086 Status NativeProcessLinux::Detach() {
1087   Status error;
1088 
1089   // Tell ptrace to detach from the process.
1090   if (GetID() == LLDB_INVALID_PROCESS_ID)
1091     return error;
1092 
1093   // Cancel out any SIGSTOPs we may have sent while stopping the process.
1094   // Otherwise, the process may stop as soon as we detach from it.
1095   kill(GetID(), SIGCONT);
1096 
1097   for (const auto &thread : m_threads) {
1098     Status e = Detach(thread->GetID());
1099      // Save the error, but still attempt to detach from other threads.
1100     if (e.Fail())
1101       error = e.Clone();
1102   }
1103 
1104   m_intel_pt_collector.Clear();
1105 
1106   return error;
1107 }
1108 
1109 Status NativeProcessLinux::Signal(int signo) {
1110   Status error;
1111 
1112   Log *log = GetLog(POSIXLog::Process);
1113   LLDB_LOG(log, "sending signal {0} ({1}) to pid {1}", signo,
1114            Host::GetSignalAsCString(signo), GetID());
1115 
1116   if (kill(GetID(), signo))
1117     error = Status::FromErrno();
1118 
1119   return error;
1120 }
1121 
1122 Status NativeProcessLinux::Interrupt() {
1123   // Pick a running thread (or if none, a not-dead stopped thread) as the
1124   // chosen thread that will be the stop-reason thread.
1125   Log *log = GetLog(POSIXLog::Process);
1126 
1127   NativeThreadProtocol *running_thread = nullptr;
1128   NativeThreadProtocol *stopped_thread = nullptr;
1129 
1130   LLDB_LOG(log, "selecting running thread for interrupt target");
1131   for (const auto &thread : m_threads) {
1132     // If we have a running or stepping thread, we'll call that the target of
1133     // the interrupt.
1134     const auto thread_state = thread->GetState();
1135     if (thread_state == eStateRunning || thread_state == eStateStepping) {
1136       running_thread = thread.get();
1137       break;
1138     } else if (!stopped_thread && StateIsStoppedState(thread_state, true)) {
1139       // Remember the first non-dead stopped thread.  We'll use that as a
1140       // backup if there are no running threads.
1141       stopped_thread = thread.get();
1142     }
1143   }
1144 
1145   if (!running_thread && !stopped_thread) {
1146     Status error("found no running/stepping or live stopped threads as target "
1147                  "for interrupt");
1148     LLDB_LOG(log, "skipping due to error: {0}", error);
1149 
1150     return error;
1151   }
1152 
1153   NativeThreadProtocol *deferred_signal_thread =
1154       running_thread ? running_thread : stopped_thread;
1155 
1156   LLDB_LOG(log, "pid {0} {1} tid {2} chosen for interrupt target", GetID(),
1157            running_thread ? "running" : "stopped",
1158            deferred_signal_thread->GetID());
1159 
1160   StopRunningThreads(deferred_signal_thread->GetID());
1161 
1162   return Status();
1163 }
1164 
1165 Status NativeProcessLinux::Kill() {
1166   Log *log = GetLog(POSIXLog::Process);
1167   LLDB_LOG(log, "pid {0}", GetID());
1168 
1169   Status error;
1170 
1171   switch (m_state) {
1172   case StateType::eStateInvalid:
1173   case StateType::eStateExited:
1174   case StateType::eStateCrashed:
1175   case StateType::eStateDetached:
1176   case StateType::eStateUnloaded:
1177     // Nothing to do - the process is already dead.
1178     LLDB_LOG(log, "ignored for PID {0} due to current state: {1}", GetID(),
1179              m_state);
1180     return error;
1181 
1182   case StateType::eStateConnected:
1183   case StateType::eStateAttaching:
1184   case StateType::eStateLaunching:
1185   case StateType::eStateStopped:
1186   case StateType::eStateRunning:
1187   case StateType::eStateStepping:
1188   case StateType::eStateSuspended:
1189     // We can try to kill a process in these states.
1190     break;
1191   }
1192 
1193   if (kill(GetID(), SIGKILL) != 0) {
1194     error = Status::FromErrno();
1195     return error;
1196   }
1197 
1198   return error;
1199 }
1200 
1201 Status NativeProcessLinux::GetMemoryRegionInfo(lldb::addr_t load_addr,
1202                                                MemoryRegionInfo &range_info) {
1203   // FIXME review that the final memory region returned extends to the end of
1204   // the virtual address space,
1205   // with no perms if it is not mapped.
1206 
1207   // Use an approach that reads memory regions from /proc/{pid}/maps. Assume
1208   // proc maps entries are in ascending order.
1209   // FIXME assert if we find differently.
1210 
1211   if (m_supports_mem_region == LazyBool::eLazyBoolNo) {
1212     // We're done.
1213     return Status::FromErrorString("unsupported");
1214   }
1215 
1216   Status error = PopulateMemoryRegionCache();
1217   if (error.Fail()) {
1218     return error;
1219   }
1220 
1221   lldb::addr_t prev_base_address = 0;
1222 
1223   // FIXME start by finding the last region that is <= target address using
1224   // binary search.  Data is sorted.
1225   // There can be a ton of regions on pthreads apps with lots of threads.
1226   for (auto it = m_mem_region_cache.begin(); it != m_mem_region_cache.end();
1227        ++it) {
1228     MemoryRegionInfo &proc_entry_info = it->first;
1229 
1230     // Sanity check assumption that /proc/{pid}/maps entries are ascending.
1231     assert((proc_entry_info.GetRange().GetRangeBase() >= prev_base_address) &&
1232            "descending /proc/pid/maps entries detected, unexpected");
1233     prev_base_address = proc_entry_info.GetRange().GetRangeBase();
1234     UNUSED_IF_ASSERT_DISABLED(prev_base_address);
1235 
1236     // If the target address comes before this entry, indicate distance to next
1237     // region.
1238     if (load_addr < proc_entry_info.GetRange().GetRangeBase()) {
1239       range_info.GetRange().SetRangeBase(load_addr);
1240       range_info.GetRange().SetByteSize(
1241           proc_entry_info.GetRange().GetRangeBase() - load_addr);
1242       range_info.SetReadable(MemoryRegionInfo::OptionalBool::eNo);
1243       range_info.SetWritable(MemoryRegionInfo::OptionalBool::eNo);
1244       range_info.SetExecutable(MemoryRegionInfo::OptionalBool::eNo);
1245       range_info.SetMapped(MemoryRegionInfo::OptionalBool::eNo);
1246 
1247       return error;
1248     } else if (proc_entry_info.GetRange().Contains(load_addr)) {
1249       // The target address is within the memory region we're processing here.
1250       range_info = proc_entry_info;
1251       return error;
1252     }
1253 
1254     // The target memory address comes somewhere after the region we just
1255     // parsed.
1256   }
1257 
1258   // If we made it here, we didn't find an entry that contained the given
1259   // address. Return the load_addr as start and the amount of bytes betwwen
1260   // load address and the end of the memory as size.
1261   range_info.GetRange().SetRangeBase(load_addr);
1262   range_info.GetRange().SetRangeEnd(LLDB_INVALID_ADDRESS);
1263   range_info.SetReadable(MemoryRegionInfo::OptionalBool::eNo);
1264   range_info.SetWritable(MemoryRegionInfo::OptionalBool::eNo);
1265   range_info.SetExecutable(MemoryRegionInfo::OptionalBool::eNo);
1266   range_info.SetMapped(MemoryRegionInfo::OptionalBool::eNo);
1267   return error;
1268 }
1269 
1270 Status NativeProcessLinux::PopulateMemoryRegionCache() {
1271   Log *log = GetLog(POSIXLog::Process);
1272 
1273   // If our cache is empty, pull the latest.  There should always be at least
1274   // one memory region if memory region handling is supported.
1275   if (!m_mem_region_cache.empty()) {
1276     LLDB_LOG(log, "reusing {0} cached memory region entries",
1277              m_mem_region_cache.size());
1278     return Status();
1279   }
1280 
1281   Status Result;
1282   LinuxMapCallback callback = [&](llvm::Expected<MemoryRegionInfo> Info) {
1283     if (Info) {
1284       FileSpec file_spec(Info->GetName().GetCString());
1285       FileSystem::Instance().Resolve(file_spec);
1286       m_mem_region_cache.emplace_back(*Info, file_spec);
1287       return true;
1288     }
1289 
1290     Result = Status::FromError(Info.takeError());
1291     m_supports_mem_region = LazyBool::eLazyBoolNo;
1292     LLDB_LOG(log, "failed to parse proc maps: {0}", Result);
1293     return false;
1294   };
1295 
1296   // Linux kernel since 2.6.14 has /proc/{pid}/smaps
1297   // if CONFIG_PROC_PAGE_MONITOR is enabled
1298   auto BufferOrError = getProcFile(GetID(), GetCurrentThreadID(), "smaps");
1299   if (BufferOrError)
1300     ParseLinuxSMapRegions(BufferOrError.get()->getBuffer(), callback);
1301   else {
1302     BufferOrError = getProcFile(GetID(), GetCurrentThreadID(), "maps");
1303     if (!BufferOrError) {
1304       m_supports_mem_region = LazyBool::eLazyBoolNo;
1305       return BufferOrError.getError();
1306     }
1307 
1308     ParseLinuxMapRegions(BufferOrError.get()->getBuffer(), callback);
1309   }
1310 
1311   if (Result.Fail())
1312     return Result;
1313 
1314   if (m_mem_region_cache.empty()) {
1315     // No entries after attempting to read them.  This shouldn't happen if
1316     // /proc/{pid}/maps is supported. Assume we don't support map entries via
1317     // procfs.
1318     m_supports_mem_region = LazyBool::eLazyBoolNo;
1319     LLDB_LOG(log,
1320              "failed to find any procfs maps entries, assuming no support "
1321              "for memory region metadata retrieval");
1322     return Status::FromErrorString("not supported");
1323   }
1324 
1325   LLDB_LOG(log, "read {0} memory region entries from /proc/{1}/maps",
1326            m_mem_region_cache.size(), GetID());
1327 
1328   // We support memory retrieval, remember that.
1329   m_supports_mem_region = LazyBool::eLazyBoolYes;
1330   return Status();
1331 }
1332 
1333 void NativeProcessLinux::DoStopIDBumped(uint32_t newBumpId) {
1334   Log *log = GetLog(POSIXLog::Process);
1335   LLDB_LOG(log, "newBumpId={0}", newBumpId);
1336   LLDB_LOG(log, "clearing {0} entries from memory region cache",
1337            m_mem_region_cache.size());
1338   m_mem_region_cache.clear();
1339 }
1340 
1341 llvm::Expected<uint64_t>
1342 NativeProcessLinux::Syscall(llvm::ArrayRef<uint64_t> args) {
1343   PopulateMemoryRegionCache();
1344   auto region_it = llvm::find_if(m_mem_region_cache, [](const auto &pair) {
1345     return pair.first.GetExecutable() == MemoryRegionInfo::eYes &&
1346         pair.first.GetShared() != MemoryRegionInfo::eYes;
1347   });
1348   if (region_it == m_mem_region_cache.end())
1349     return llvm::createStringError(llvm::inconvertibleErrorCode(),
1350                                    "No executable memory region found!");
1351 
1352   addr_t exe_addr = region_it->first.GetRange().GetRangeBase();
1353 
1354   NativeThreadLinux &thread = *GetCurrentThread();
1355   assert(thread.GetState() == eStateStopped);
1356   NativeRegisterContextLinux &reg_ctx = thread.GetRegisterContext();
1357 
1358   NativeRegisterContextLinux::SyscallData syscall_data =
1359       *reg_ctx.GetSyscallData();
1360 
1361   WritableDataBufferSP registers_sp;
1362   if (llvm::Error Err = reg_ctx.ReadAllRegisterValues(registers_sp).ToError())
1363     return std::move(Err);
1364   auto restore_regs = llvm::make_scope_exit(
1365       [&] { reg_ctx.WriteAllRegisterValues(registers_sp); });
1366 
1367   llvm::SmallVector<uint8_t, 8> memory(syscall_data.Insn.size());
1368   size_t bytes_read;
1369   if (llvm::Error Err =
1370           ReadMemory(exe_addr, memory.data(), memory.size(), bytes_read)
1371               .ToError()) {
1372     return std::move(Err);
1373   }
1374 
1375   auto restore_mem = llvm::make_scope_exit(
1376       [&] { WriteMemory(exe_addr, memory.data(), memory.size(), bytes_read); });
1377 
1378   if (llvm::Error Err = reg_ctx.SetPC(exe_addr).ToError())
1379     return std::move(Err);
1380 
1381   for (const auto &zip : llvm::zip_first(args, syscall_data.Args)) {
1382     if (llvm::Error Err =
1383             reg_ctx
1384                 .WriteRegisterFromUnsigned(std::get<1>(zip), std::get<0>(zip))
1385                 .ToError()) {
1386       return std::move(Err);
1387     }
1388   }
1389   if (llvm::Error Err = WriteMemory(exe_addr, syscall_data.Insn.data(),
1390                                     syscall_data.Insn.size(), bytes_read)
1391                             .ToError())
1392     return std::move(Err);
1393 
1394   m_mem_region_cache.clear();
1395 
1396   // With software single stepping the syscall insn buffer must also include a
1397   // trap instruction to stop the process.
1398   int req = SupportHardwareSingleStepping() ? PTRACE_SINGLESTEP : PTRACE_CONT;
1399   if (llvm::Error Err =
1400           PtraceWrapper(req, thread.GetID(), nullptr, nullptr).ToError())
1401     return std::move(Err);
1402 
1403   int status;
1404   ::pid_t wait_pid = llvm::sys::RetryAfterSignal(-1, ::waitpid, thread.GetID(),
1405                                                  &status, __WALL);
1406   if (wait_pid == -1) {
1407     return llvm::errorCodeToError(
1408         std::error_code(errno, std::generic_category()));
1409   }
1410   assert((unsigned)wait_pid == thread.GetID());
1411 
1412   uint64_t result = reg_ctx.ReadRegisterAsUnsigned(syscall_data.Result, -ESRCH);
1413 
1414   // Values larger than this are actually negative errno numbers.
1415   uint64_t errno_threshold =
1416       (uint64_t(-1) >> (64 - 8 * m_arch.GetAddressByteSize())) - 0x1000;
1417   if (result > errno_threshold) {
1418     return llvm::errorCodeToError(
1419         std::error_code(-result & 0xfff, std::generic_category()));
1420   }
1421 
1422   return result;
1423 }
1424 
1425 llvm::Expected<addr_t>
1426 NativeProcessLinux::AllocateMemory(size_t size, uint32_t permissions) {
1427 
1428   std::optional<NativeRegisterContextLinux::MmapData> mmap_data =
1429       GetCurrentThread()->GetRegisterContext().GetMmapData();
1430   if (!mmap_data)
1431     return llvm::make_error<UnimplementedError>();
1432 
1433   unsigned prot = PROT_NONE;
1434   assert((permissions & (ePermissionsReadable | ePermissionsWritable |
1435                          ePermissionsExecutable)) == permissions &&
1436          "Unknown permission!");
1437   if (permissions & ePermissionsReadable)
1438     prot |= PROT_READ;
1439   if (permissions & ePermissionsWritable)
1440     prot |= PROT_WRITE;
1441   if (permissions & ePermissionsExecutable)
1442     prot |= PROT_EXEC;
1443 
1444   llvm::Expected<uint64_t> Result =
1445       Syscall({mmap_data->SysMmap, 0, size, prot, MAP_ANONYMOUS | MAP_PRIVATE,
1446                uint64_t(-1), 0});
1447   if (Result)
1448     m_allocated_memory.try_emplace(*Result, size);
1449   return Result;
1450 }
1451 
1452 llvm::Error NativeProcessLinux::DeallocateMemory(lldb::addr_t addr) {
1453   std::optional<NativeRegisterContextLinux::MmapData> mmap_data =
1454       GetCurrentThread()->GetRegisterContext().GetMmapData();
1455   if (!mmap_data)
1456     return llvm::make_error<UnimplementedError>();
1457 
1458   auto it = m_allocated_memory.find(addr);
1459   if (it == m_allocated_memory.end())
1460     return llvm::createStringError(llvm::errc::invalid_argument,
1461                                    "Memory not allocated by the debugger.");
1462 
1463   llvm::Expected<uint64_t> Result =
1464       Syscall({mmap_data->SysMunmap, addr, it->second});
1465   if (!Result)
1466     return Result.takeError();
1467 
1468   m_allocated_memory.erase(it);
1469   return llvm::Error::success();
1470 }
1471 
1472 Status NativeProcessLinux::ReadMemoryTags(int32_t type, lldb::addr_t addr,
1473                                           size_t len,
1474                                           std::vector<uint8_t> &tags) {
1475   llvm::Expected<NativeRegisterContextLinux::MemoryTaggingDetails> details =
1476       GetCurrentThread()->GetRegisterContext().GetMemoryTaggingDetails(type);
1477   if (!details)
1478     return Status::FromError(details.takeError());
1479 
1480   // Ignore 0 length read
1481   if (!len)
1482     return Status();
1483 
1484   // lldb will align the range it requests but it is not required to by
1485   // the protocol so we'll do it again just in case.
1486   // Remove tag bits too. Ptrace calls may work regardless but that
1487   // is not a guarantee.
1488   MemoryTagManager::TagRange range(details->manager->RemoveTagBits(addr), len);
1489   range = details->manager->ExpandToGranule(range);
1490 
1491   // Allocate enough space for all tags to be read
1492   size_t num_tags = range.GetByteSize() / details->manager->GetGranuleSize();
1493   tags.resize(num_tags * details->manager->GetTagSizeInBytes());
1494 
1495   struct iovec tags_iovec;
1496   uint8_t *dest = tags.data();
1497   lldb::addr_t read_addr = range.GetRangeBase();
1498 
1499   // This call can return partial data so loop until we error or
1500   // get all tags back.
1501   while (num_tags) {
1502     tags_iovec.iov_base = dest;
1503     tags_iovec.iov_len = num_tags;
1504 
1505     Status error = NativeProcessLinux::PtraceWrapper(
1506         details->ptrace_read_req, GetCurrentThreadID(),
1507         reinterpret_cast<void *>(read_addr), static_cast<void *>(&tags_iovec),
1508         0, nullptr);
1509 
1510     if (error.Fail()) {
1511       // Discard partial reads
1512       tags.resize(0);
1513       return error;
1514     }
1515 
1516     size_t tags_read = tags_iovec.iov_len;
1517     assert(tags_read && (tags_read <= num_tags));
1518 
1519     dest += tags_read * details->manager->GetTagSizeInBytes();
1520     read_addr += details->manager->GetGranuleSize() * tags_read;
1521     num_tags -= tags_read;
1522   }
1523 
1524   return Status();
1525 }
1526 
1527 Status NativeProcessLinux::WriteMemoryTags(int32_t type, lldb::addr_t addr,
1528                                            size_t len,
1529                                            const std::vector<uint8_t> &tags) {
1530   llvm::Expected<NativeRegisterContextLinux::MemoryTaggingDetails> details =
1531       GetCurrentThread()->GetRegisterContext().GetMemoryTaggingDetails(type);
1532   if (!details)
1533     return Status::FromError(details.takeError());
1534 
1535   // Ignore 0 length write
1536   if (!len)
1537     return Status();
1538 
1539   // lldb will align the range it requests but it is not required to by
1540   // the protocol so we'll do it again just in case.
1541   // Remove tag bits too. Ptrace calls may work regardless but that
1542   // is not a guarantee.
1543   MemoryTagManager::TagRange range(details->manager->RemoveTagBits(addr), len);
1544   range = details->manager->ExpandToGranule(range);
1545 
1546   // Not checking number of tags here, we may repeat them below
1547   llvm::Expected<std::vector<lldb::addr_t>> unpacked_tags_or_err =
1548       details->manager->UnpackTagsData(tags);
1549   if (!unpacked_tags_or_err)
1550     return Status::FromError(unpacked_tags_or_err.takeError());
1551 
1552   llvm::Expected<std::vector<lldb::addr_t>> repeated_tags_or_err =
1553       details->manager->RepeatTagsForRange(*unpacked_tags_or_err, range);
1554   if (!repeated_tags_or_err)
1555     return Status::FromError(repeated_tags_or_err.takeError());
1556 
1557   // Repack them for ptrace to use
1558   llvm::Expected<std::vector<uint8_t>> final_tag_data =
1559       details->manager->PackTags(*repeated_tags_or_err);
1560   if (!final_tag_data)
1561     return Status::FromError(final_tag_data.takeError());
1562 
1563   struct iovec tags_vec;
1564   uint8_t *src = final_tag_data->data();
1565   lldb::addr_t write_addr = range.GetRangeBase();
1566   // unpacked tags size because the number of bytes per tag might not be 1
1567   size_t num_tags = repeated_tags_or_err->size();
1568 
1569   // This call can partially write tags, so we loop until we
1570   // error or all tags have been written.
1571   while (num_tags > 0) {
1572     tags_vec.iov_base = src;
1573     tags_vec.iov_len = num_tags;
1574 
1575     Status error = NativeProcessLinux::PtraceWrapper(
1576         details->ptrace_write_req, GetCurrentThreadID(),
1577         reinterpret_cast<void *>(write_addr), static_cast<void *>(&tags_vec), 0,
1578         nullptr);
1579 
1580     if (error.Fail()) {
1581       // Don't attempt to restore the original values in the case of a partial
1582       // write
1583       return error;
1584     }
1585 
1586     size_t tags_written = tags_vec.iov_len;
1587     assert(tags_written && (tags_written <= num_tags));
1588 
1589     src += tags_written * details->manager->GetTagSizeInBytes();
1590     write_addr += details->manager->GetGranuleSize() * tags_written;
1591     num_tags -= tags_written;
1592   }
1593 
1594   return Status();
1595 }
1596 
1597 size_t NativeProcessLinux::UpdateThreads() {
1598   // The NativeProcessLinux monitoring threads are always up to date with
1599   // respect to thread state and they keep the thread list populated properly.
1600   // All this method needs to do is return the thread count.
1601   return m_threads.size();
1602 }
1603 
1604 Status NativeProcessLinux::SetBreakpoint(lldb::addr_t addr, uint32_t size,
1605                                          bool hardware) {
1606   if (hardware)
1607     return SetHardwareBreakpoint(addr, size);
1608   else
1609     return SetSoftwareBreakpoint(addr, size);
1610 }
1611 
1612 Status NativeProcessLinux::RemoveBreakpoint(lldb::addr_t addr, bool hardware) {
1613   if (hardware)
1614     return RemoveHardwareBreakpoint(addr);
1615   else
1616     return NativeProcessProtocol::RemoveBreakpoint(addr);
1617 }
1618 
1619 llvm::Expected<llvm::ArrayRef<uint8_t>>
1620 NativeProcessLinux::GetSoftwareBreakpointTrapOpcode(size_t size_hint) {
1621   // The ARM reference recommends the use of 0xe7fddefe and 0xdefe but the
1622   // linux kernel does otherwise.
1623   static const uint8_t g_arm_opcode[] = {0xf0, 0x01, 0xf0, 0xe7};
1624   static const uint8_t g_thumb_opcode[] = {0x01, 0xde};
1625 
1626   switch (GetArchitecture().GetMachine()) {
1627   case llvm::Triple::arm:
1628     switch (size_hint) {
1629     case 2:
1630       return llvm::ArrayRef(g_thumb_opcode);
1631     case 4:
1632       return llvm::ArrayRef(g_arm_opcode);
1633     default:
1634       return llvm::createStringError(llvm::inconvertibleErrorCode(),
1635                                      "Unrecognised trap opcode size hint!");
1636     }
1637   default:
1638     return NativeProcessProtocol::GetSoftwareBreakpointTrapOpcode(size_hint);
1639   }
1640 }
1641 
1642 Status NativeProcessLinux::ReadMemory(lldb::addr_t addr, void *buf, size_t size,
1643                                       size_t &bytes_read) {
1644   Log *log = GetLog(POSIXLog::Memory);
1645   LLDB_LOG(log, "addr = {0}, buf = {1}, size = {2}", addr, buf, size);
1646 
1647   bytes_read = 0;
1648   if (ProcessVmReadvSupported()) {
1649     // The process_vm_readv path is about 50 times faster than ptrace api. We
1650     // want to use this syscall if it is supported.
1651 
1652     struct iovec local_iov, remote_iov;
1653     local_iov.iov_base = buf;
1654     local_iov.iov_len = size;
1655     remote_iov.iov_base = reinterpret_cast<void *>(addr);
1656     remote_iov.iov_len = size;
1657 
1658     ssize_t read_result = process_vm_readv(GetCurrentThreadID(), &local_iov, 1,
1659                                            &remote_iov, 1, 0);
1660     int error = 0;
1661     if (read_result < 0)
1662       error = errno;
1663     else
1664       bytes_read = read_result;
1665 
1666     LLDB_LOG(log,
1667              "process_vm_readv({0}, [iovec({1}, {2})], [iovec({3:x}, {2})], 1, "
1668              "0) => {4} ({5})",
1669              GetCurrentThreadID(), buf, size, addr, read_result,
1670              error > 0 ? llvm::sys::StrError(errno) : "sucesss");
1671   }
1672 
1673   unsigned char *dst = static_cast<unsigned char *>(buf);
1674   size_t remainder;
1675   long data;
1676 
1677   for (; bytes_read < size; bytes_read += remainder) {
1678     Status error = NativeProcessLinux::PtraceWrapper(
1679         PTRACE_PEEKDATA, GetCurrentThreadID(),
1680         reinterpret_cast<void *>(addr + bytes_read), nullptr, 0, &data);
1681     if (error.Fail())
1682       return error;
1683 
1684     remainder = size - bytes_read;
1685     remainder = remainder > k_ptrace_word_size ? k_ptrace_word_size : remainder;
1686 
1687     // Copy the data into our buffer
1688     memcpy(dst + bytes_read, &data, remainder);
1689   }
1690   return Status();
1691 }
1692 
1693 Status NativeProcessLinux::WriteMemory(lldb::addr_t addr, const void *buf,
1694                                        size_t size, size_t &bytes_written) {
1695   const unsigned char *src = static_cast<const unsigned char *>(buf);
1696   size_t remainder;
1697   Status error;
1698 
1699   Log *log = GetLog(POSIXLog::Memory);
1700   LLDB_LOG(log, "addr = {0}, buf = {1}, size = {2}", addr, buf, size);
1701 
1702   for (bytes_written = 0; bytes_written < size; bytes_written += remainder) {
1703     remainder = size - bytes_written;
1704     remainder = remainder > k_ptrace_word_size ? k_ptrace_word_size : remainder;
1705 
1706     if (remainder == k_ptrace_word_size) {
1707       unsigned long data = 0;
1708       memcpy(&data, src, k_ptrace_word_size);
1709 
1710       LLDB_LOG(log, "[{0:x}]:{1:x}", addr, data);
1711       error = NativeProcessLinux::PtraceWrapper(
1712           PTRACE_POKEDATA, GetCurrentThreadID(), (void *)addr, (void *)data);
1713       if (error.Fail())
1714         return error;
1715     } else {
1716       unsigned char buff[8];
1717       size_t bytes_read;
1718       error = ReadMemory(addr, buff, k_ptrace_word_size, bytes_read);
1719       if (error.Fail())
1720         return error;
1721 
1722       memcpy(buff, src, remainder);
1723 
1724       size_t bytes_written_rec;
1725       error = WriteMemory(addr, buff, k_ptrace_word_size, bytes_written_rec);
1726       if (error.Fail())
1727         return error;
1728 
1729       LLDB_LOG(log, "[{0:x}]:{1:x} ({2:x})", addr, *(const unsigned long *)src,
1730                *(unsigned long *)buff);
1731     }
1732 
1733     addr += k_ptrace_word_size;
1734     src += k_ptrace_word_size;
1735   }
1736   return error;
1737 }
1738 
1739 Status NativeProcessLinux::GetSignalInfo(lldb::tid_t tid, void *siginfo) const {
1740   return PtraceWrapper(PTRACE_GETSIGINFO, tid, nullptr, siginfo);
1741 }
1742 
1743 Status NativeProcessLinux::GetEventMessage(lldb::tid_t tid,
1744                                            unsigned long *message) {
1745   return PtraceWrapper(PTRACE_GETEVENTMSG, tid, nullptr, message);
1746 }
1747 
1748 Status NativeProcessLinux::Detach(lldb::tid_t tid) {
1749   if (tid == LLDB_INVALID_THREAD_ID)
1750     return Status();
1751 
1752   return PtraceWrapper(PTRACE_DETACH, tid);
1753 }
1754 
1755 bool NativeProcessLinux::HasThreadNoLock(lldb::tid_t thread_id) {
1756   for (const auto &thread : m_threads) {
1757     assert(thread && "thread list should not contain NULL threads");
1758     if (thread->GetID() == thread_id) {
1759       // We have this thread.
1760       return true;
1761     }
1762   }
1763 
1764   // We don't have this thread.
1765   return false;
1766 }
1767 
1768 void NativeProcessLinux::StopTrackingThread(NativeThreadLinux &thread) {
1769   Log *const log = GetLog(POSIXLog::Thread);
1770   lldb::tid_t thread_id = thread.GetID();
1771   LLDB_LOG(log, "tid: {0}", thread_id);
1772 
1773   auto it = llvm::find_if(m_threads, [&](const auto &thread_up) {
1774     return thread_up.get() == &thread;
1775   });
1776   assert(it != m_threads.end());
1777   m_threads.erase(it);
1778 
1779   NotifyTracersOfThreadDestroyed(thread_id);
1780   SignalIfAllThreadsStopped();
1781 }
1782 
1783 void NativeProcessLinux::NotifyTracersProcessDidStop() {
1784   m_intel_pt_collector.ProcessDidStop();
1785 }
1786 
1787 void NativeProcessLinux::NotifyTracersProcessWillResume() {
1788   m_intel_pt_collector.ProcessWillResume();
1789 }
1790 
1791 Status NativeProcessLinux::NotifyTracersOfNewThread(lldb::tid_t tid) {
1792   Log *log = GetLog(POSIXLog::Thread);
1793   Status error = Status::FromError(m_intel_pt_collector.OnThreadCreated(tid));
1794   if (error.Fail())
1795     LLDB_LOG(log, "Failed to trace a new thread with intel-pt, tid = {0}. {1}",
1796              tid, error.AsCString());
1797   return error;
1798 }
1799 
1800 Status NativeProcessLinux::NotifyTracersOfThreadDestroyed(lldb::tid_t tid) {
1801   Log *log = GetLog(POSIXLog::Thread);
1802   Status error = Status::FromError(m_intel_pt_collector.OnThreadDestroyed(tid));
1803   if (error.Fail())
1804     LLDB_LOG(log,
1805              "Failed to stop a destroyed thread with intel-pt, tid = {0}. {1}",
1806              tid, error.AsCString());
1807   return error;
1808 }
1809 
1810 NativeThreadLinux &NativeProcessLinux::AddThread(lldb::tid_t thread_id,
1811                                                  bool resume) {
1812   Log *log = GetLog(POSIXLog::Thread);
1813   LLDB_LOG(log, "pid {0} adding thread with tid {1}", GetID(), thread_id);
1814 
1815   assert(!HasThreadNoLock(thread_id) &&
1816          "attempted to add a thread by id that already exists");
1817 
1818   // If this is the first thread, save it as the current thread
1819   if (m_threads.empty())
1820     SetCurrentThreadID(thread_id);
1821 
1822   m_threads.push_back(std::make_unique<NativeThreadLinux>(*this, thread_id));
1823   NativeThreadLinux &thread =
1824       static_cast<NativeThreadLinux &>(*m_threads.back());
1825 
1826   Status tracing_error = NotifyTracersOfNewThread(thread.GetID());
1827   if (tracing_error.Fail()) {
1828     thread.SetStoppedByProcessorTrace(tracing_error.AsCString());
1829     StopRunningThreads(thread.GetID());
1830   } else if (resume)
1831     ResumeThread(thread, eStateRunning, LLDB_INVALID_SIGNAL_NUMBER);
1832   else
1833     thread.SetStoppedBySignal(SIGSTOP);
1834 
1835   return thread;
1836 }
1837 
1838 Status NativeProcessLinux::GetLoadedModuleFileSpec(const char *module_path,
1839                                                    FileSpec &file_spec) {
1840   Status error = PopulateMemoryRegionCache();
1841   if (error.Fail())
1842     return error;
1843 
1844   FileSpec module_file_spec(module_path);
1845   FileSystem::Instance().Resolve(module_file_spec);
1846 
1847   file_spec.Clear();
1848   for (const auto &it : m_mem_region_cache) {
1849     if (it.second.GetFilename() == module_file_spec.GetFilename()) {
1850       file_spec = it.second;
1851       return Status();
1852     }
1853   }
1854   return Status::FromErrorStringWithFormat(
1855       "Module file (%s) not found in /proc/%" PRIu64 "/maps file!",
1856       module_file_spec.GetFilename().AsCString(), GetID());
1857 }
1858 
1859 Status NativeProcessLinux::GetFileLoadAddress(const llvm::StringRef &file_name,
1860                                               lldb::addr_t &load_addr) {
1861   load_addr = LLDB_INVALID_ADDRESS;
1862   Status error = PopulateMemoryRegionCache();
1863   if (error.Fail())
1864     return error;
1865 
1866   FileSpec file(file_name);
1867   for (const auto &it : m_mem_region_cache) {
1868     if (it.second == file) {
1869       load_addr = it.first.GetRange().GetRangeBase();
1870       return Status();
1871     }
1872   }
1873   return Status::FromErrorString("No load address found for specified file.");
1874 }
1875 
1876 NativeThreadLinux *NativeProcessLinux::GetThreadByID(lldb::tid_t tid) {
1877   return static_cast<NativeThreadLinux *>(
1878       NativeProcessProtocol::GetThreadByID(tid));
1879 }
1880 
1881 NativeThreadLinux *NativeProcessLinux::GetCurrentThread() {
1882   return static_cast<NativeThreadLinux *>(
1883       NativeProcessProtocol::GetCurrentThread());
1884 }
1885 
1886 Status NativeProcessLinux::ResumeThread(NativeThreadLinux &thread,
1887                                         lldb::StateType state, int signo) {
1888   Log *const log = GetLog(POSIXLog::Thread);
1889   LLDB_LOG(log, "tid: {0}", thread.GetID());
1890 
1891   // Before we do the resume below, first check if we have a pending stop
1892   // notification that is currently waiting for all threads to stop.  This is
1893   // potentially a buggy situation since we're ostensibly waiting for threads
1894   // to stop before we send out the pending notification, and here we are
1895   // resuming one before we send out the pending stop notification.
1896   if (m_pending_notification_tid != LLDB_INVALID_THREAD_ID) {
1897     LLDB_LOG(log,
1898              "about to resume tid {0} per explicit request but we have a "
1899              "pending stop notification (tid {1}) that is actively "
1900              "waiting for this thread to stop. Valid sequence of events?",
1901              thread.GetID(), m_pending_notification_tid);
1902   }
1903 
1904   // Request a resume.  We expect this to be synchronous and the system to
1905   // reflect it is running after this completes.
1906   switch (state) {
1907   case eStateRunning: {
1908     Status resume_result = thread.Resume(signo);
1909     if (resume_result.Success())
1910       SetState(eStateRunning, true);
1911     return resume_result;
1912   }
1913   case eStateStepping: {
1914     Status step_result = thread.SingleStep(signo);
1915     if (step_result.Success())
1916       SetState(eStateRunning, true);
1917     return step_result;
1918   }
1919   default:
1920     LLDB_LOG(log, "Unhandled state {0}.", state);
1921     llvm_unreachable("Unhandled state for resume");
1922   }
1923 }
1924 
1925 //===----------------------------------------------------------------------===//
1926 
1927 void NativeProcessLinux::StopRunningThreads(const lldb::tid_t triggering_tid) {
1928   Log *const log = GetLog(POSIXLog::Thread);
1929   LLDB_LOG(log, "about to process event: (triggering_tid: {0})",
1930            triggering_tid);
1931 
1932   m_pending_notification_tid = triggering_tid;
1933 
1934   // Request a stop for all the thread stops that need to be stopped and are
1935   // not already known to be stopped.
1936   for (const auto &thread : m_threads) {
1937     if (StateIsRunningState(thread->GetState()))
1938       static_cast<NativeThreadLinux *>(thread.get())->RequestStop();
1939   }
1940 
1941   SignalIfAllThreadsStopped();
1942   LLDB_LOG(log, "event processing done");
1943 }
1944 
1945 void NativeProcessLinux::SignalIfAllThreadsStopped() {
1946   if (m_pending_notification_tid == LLDB_INVALID_THREAD_ID)
1947     return; // No pending notification. Nothing to do.
1948 
1949   for (const auto &thread_sp : m_threads) {
1950     if (StateIsRunningState(thread_sp->GetState()))
1951       return; // Some threads are still running. Don't signal yet.
1952   }
1953 
1954   // We have a pending notification and all threads have stopped.
1955   Log *log = GetLog(LLDBLog::Process | LLDBLog::Breakpoints);
1956 
1957   // Clear any temporary breakpoints we used to implement software single
1958   // stepping.
1959   for (const auto &thread_info : m_threads_stepping_with_breakpoint) {
1960     Status error = RemoveBreakpoint(thread_info.second);
1961     if (error.Fail())
1962       LLDB_LOG(log, "pid = {0} remove stepping breakpoint: {1}",
1963                thread_info.first, error);
1964   }
1965   m_threads_stepping_with_breakpoint.clear();
1966 
1967   // Notify the delegate about the stop
1968   SetCurrentThreadID(m_pending_notification_tid);
1969   SetState(StateType::eStateStopped, true);
1970   m_pending_notification_tid = LLDB_INVALID_THREAD_ID;
1971 }
1972 
1973 void NativeProcessLinux::ThreadWasCreated(NativeThreadLinux &thread) {
1974   Log *const log = GetLog(POSIXLog::Thread);
1975   LLDB_LOG(log, "tid: {0}", thread.GetID());
1976 
1977   if (m_pending_notification_tid != LLDB_INVALID_THREAD_ID &&
1978       StateIsRunningState(thread.GetState())) {
1979     // We will need to wait for this new thread to stop as well before firing
1980     // the notification.
1981     thread.RequestStop();
1982   }
1983 }
1984 
1985 // Wrapper for ptrace to catch errors and log calls. Note that ptrace sets
1986 // errno on error because -1 can be a valid result (i.e. for PTRACE_PEEK*)
1987 Status NativeProcessLinux::PtraceWrapper(int req, lldb::pid_t pid, void *addr,
1988                                          void *data, size_t data_size,
1989                                          long *result) {
1990   Status error;
1991   long int ret;
1992 
1993   Log *log = GetLog(POSIXLog::Ptrace);
1994 
1995   PtraceDisplayBytes(req, data, data_size);
1996 
1997   errno = 0;
1998   if (req == PTRACE_GETREGSET || req == PTRACE_SETREGSET)
1999     ret = ptrace(static_cast<__ptrace_request>(req), static_cast<::pid_t>(pid),
2000                  *(unsigned int *)addr, data);
2001   else
2002     ret = ptrace(static_cast<__ptrace_request>(req), static_cast<::pid_t>(pid),
2003                  addr, data);
2004 
2005   if (ret == -1)
2006     error = Status::FromErrno();
2007 
2008   if (result)
2009     *result = ret;
2010 
2011   LLDB_LOG(log, "ptrace({0}, {1}, {2}, {3}, {4})={5:x}", req, pid, addr, data,
2012            data_size, ret);
2013 
2014   PtraceDisplayBytes(req, data, data_size);
2015 
2016   if (error.Fail())
2017     LLDB_LOG(log, "ptrace() failed: {0}", error);
2018 
2019   return error;
2020 }
2021 
2022 llvm::Expected<TraceSupportedResponse> NativeProcessLinux::TraceSupported() {
2023   if (IntelPTCollector::IsSupported())
2024     return TraceSupportedResponse{"intel-pt", "Intel Processor Trace"};
2025   return NativeProcessProtocol::TraceSupported();
2026 }
2027 
2028 Error NativeProcessLinux::TraceStart(StringRef json_request, StringRef type) {
2029   if (type == "intel-pt") {
2030     if (Expected<TraceIntelPTStartRequest> request =
2031             json::parse<TraceIntelPTStartRequest>(json_request,
2032                                                   "TraceIntelPTStartRequest")) {
2033       return m_intel_pt_collector.TraceStart(*request);
2034     } else
2035       return request.takeError();
2036   }
2037 
2038   return NativeProcessProtocol::TraceStart(json_request, type);
2039 }
2040 
2041 Error NativeProcessLinux::TraceStop(const TraceStopRequest &request) {
2042   if (request.type == "intel-pt")
2043     return m_intel_pt_collector.TraceStop(request);
2044   return NativeProcessProtocol::TraceStop(request);
2045 }
2046 
2047 Expected<json::Value> NativeProcessLinux::TraceGetState(StringRef type) {
2048   if (type == "intel-pt")
2049     return m_intel_pt_collector.GetState();
2050   return NativeProcessProtocol::TraceGetState(type);
2051 }
2052 
2053 Expected<std::vector<uint8_t>> NativeProcessLinux::TraceGetBinaryData(
2054     const TraceGetBinaryDataRequest &request) {
2055   if (request.type == "intel-pt")
2056     return m_intel_pt_collector.GetBinaryData(request);
2057   return NativeProcessProtocol::TraceGetBinaryData(request);
2058 }
2059