1 //===-- NativeProcessDarwin.h --------------------------------- -*- C++ -*-===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 
10 #ifndef NativeProcessDarwin_h
11 #define NativeProcessDarwin_h
12 
13 // NOTE: this code should only be compiled on Apple Darwin systems.  It is
14 // not cross-platform code and is not intended to build on any other platform.
15 // Therefore, platform-specific headers and code are okay here.
16 
17 // C includes
18 #include <mach/mach_types.h>
19 
20 // C++ includes
21 #include <mutex>
22 #include <unordered_set>
23 
24 // Other libraries and framework includes
25 #include "lldb/Host/Debug.h"
26 #include "lldb/Host/HostThread.h"
27 #include "lldb/Host/Pipe.h"
28 #include "lldb/Host/common/NativeProcessProtocol.h"
29 #include "lldb/Target/MemoryRegionInfo.h"
30 #include "lldb/Utility/ArchSpec.h"
31 #include "lldb/Utility/FileSpec.h"
32 #include "lldb/lldb-types.h"
33 
34 #include "LaunchFlavor.h"
35 #include "MachException.h"
36 #include "NativeThreadDarwin.h"
37 #include "NativeThreadListDarwin.h"
38 
39 namespace lldb_private {
40 class Status;
41 class Scalar;
42 
43 namespace process_darwin {
44 
45 /// @class NativeProcessDarwin
46 /// @brief Manages communication with the inferior (debugee) process.
47 ///
48 /// Upon construction, this class prepares and launches an inferior
49 /// process for debugging.
50 ///
51 /// Changes in the inferior process state are broadcasted.
52 class NativeProcessDarwin : public NativeProcessProtocol {
53   friend Status NativeProcessProtocol::Launch(
54       ProcessLaunchInfo &launch_info, NativeDelegate &native_delegate,
55       MainLoop &mainloop, NativeProcessProtocolSP &process_sp);
56 
57   friend Status NativeProcessProtocol::Attach(
58       lldb::pid_t pid, NativeProcessProtocol::NativeDelegate &native_delegate,
59       MainLoop &mainloop, NativeProcessProtocolSP &process_sp);
60 
61 public:
62   ~NativeProcessDarwin() override;
63 
64   // -----------------------------------------------------------------
65   // NativeProcessProtocol Interface
66   // -----------------------------------------------------------------
67   Status Resume(const ResumeActionList &resume_actions) override;
68 
69   Status Halt() override;
70 
71   Status Detach() override;
72 
73   Status Signal(int signo) override;
74 
75   Status Interrupt() override;
76 
77   Status Kill() override;
78 
79   Status GetMemoryRegionInfo(lldb::addr_t load_addr,
80                              MemoryRegionInfo &range_info) override;
81 
82   Status ReadMemory(lldb::addr_t addr, void *buf, size_t size,
83                     size_t &bytes_read) override;
84 
85   Status ReadMemoryWithoutTrap(lldb::addr_t addr, void *buf, size_t size,
86                                size_t &bytes_read) override;
87 
88   Status WriteMemory(lldb::addr_t addr, const void *buf, size_t size,
89                      size_t &bytes_written) override;
90 
91   Status AllocateMemory(size_t size, uint32_t permissions,
92                         lldb::addr_t &addr) override;
93 
94   Status DeallocateMemory(lldb::addr_t addr) override;
95 
96   lldb::addr_t GetSharedLibraryInfoAddress() override;
97 
98   size_t UpdateThreads() override;
99 
100   bool GetArchitecture(ArchSpec &arch) const override;
101 
102   Status SetBreakpoint(lldb::addr_t addr, uint32_t size,
103                        bool hardware) override;
104 
105   void DoStopIDBumped(uint32_t newBumpId) override;
106 
107   Status GetLoadedModuleFileSpec(const char *module_path,
108                                  FileSpec &file_spec) override;
109 
110   Status GetFileLoadAddress(const llvm::StringRef &file_name,
111                             lldb::addr_t &load_addr) override;
112 
113   NativeThreadDarwinSP GetThreadByID(lldb::tid_t id);
114 
115   task_t GetTask() const { return m_task; }
116 
117   // -----------------------------------------------------------------
118   // Interface used by NativeRegisterContext-derived classes.
119   // -----------------------------------------------------------------
120   static Status PtraceWrapper(int req, lldb::pid_t pid, void *addr = nullptr,
121                               void *data = nullptr, size_t data_size = 0,
122                               long *result = nullptr);
123 
124   bool SupportHardwareSingleStepping() const;
125 
126 protected:
127   // -----------------------------------------------------------------
128   // NativeProcessProtocol protected interface
129   // -----------------------------------------------------------------
130   Status
131   GetSoftwareBreakpointTrapOpcode(size_t trap_opcode_size_hint,
132                                   size_t &actual_opcode_size,
133                                   const uint8_t *&trap_opcode_bytes) override;
134 
135 private:
136   // -----------------------------------------------------------------
137   /// Mach task-related Member Variables
138   // -----------------------------------------------------------------
139 
140   // The task port for the inferior process.
141   mutable task_t m_task;
142 
143   // True if the inferior process did an exec since we started
144   // monitoring it.
145   bool m_did_exec;
146 
147   // The CPU type of this process.
148   mutable cpu_type_t m_cpu_type;
149 
150   // -----------------------------------------------------------------
151   /// Exception/Signal Handling Member Variables
152   // -----------------------------------------------------------------
153 
154   // Exception port on which we will receive child exceptions
155   mach_port_t m_exception_port;
156 
157   // Saved state of the child exception port prior to us installing
158   // our own intercepting port.
159   MachException::PortInfo m_exc_port_info;
160 
161   // The thread that runs the Mach exception read and reply handler.
162   pthread_t m_exception_thread;
163 
164   // TODO see if we can remove this if we get the exception collection
165   // and distribution to happen in a single-threaded fashion.
166   std::recursive_mutex m_exception_messages_mutex;
167 
168   // A collection of exception messages caught when listening to the
169   // exception port.
170   MachException::Message::collection m_exception_messages;
171 
172   // When we call MachProcess::Interrupt(), we want to send this
173   // signal (if non-zero).
174   int m_sent_interrupt_signo;
175 
176   // If we resume the process and still haven't received our
177   // interrupt signal (if this is non-zero).
178   int m_auto_resume_signo;
179 
180   // -----------------------------------------------------------------
181   /// Thread-related Member Variables
182   // -----------------------------------------------------------------
183   NativeThreadListDarwin m_thread_list;
184   ResumeActionList m_thread_actions;
185 
186   // -----------------------------------------------------------------
187   /// Process Lifetime Member Variable
188   // -----------------------------------------------------------------
189 
190   // The pipe over which the waitpid thread and the main loop will
191   // communicate.
192   Pipe m_waitpid_pipe;
193 
194   // The thread that runs the waitpid handler.
195   pthread_t m_waitpid_thread;
196 
197   // waitpid reader callback handle.
198   MainLoop::ReadHandleUP m_waitpid_reader_handle;
199 
200   // -----------------------------------------------------------------
201   // Private Instance Methods
202   // -----------------------------------------------------------------
203   NativeProcessDarwin(lldb::pid_t pid, int pty_master_fd);
204 
205   // -----------------------------------------------------------------
206   /// Finalize the launch.
207   ///
208   /// This method associates the NativeProcessDarwin instance with
209   /// the host process that was just launched.  It peforms actions
210   /// like attaching a listener to the inferior exception port,
211   /// ptracing the process, and the like.
212   ///
213   /// @param[in] launch_flavor
214   ///     The launch flavor that was used to launch the process.
215   ///
216   /// @param[in] main_loop
217   ///     The main loop that will run the process monitor.  Work
218   ///     that needs to be done (e.g. reading files) gets registered
219   ///     here along with callbacks to process the work.
220   ///
221   /// @return
222   ///     Any error that occurred during the aforementioned
223   ///     operations.  Failure here will force termination of the
224   ///     launched process and debugging session.
225   // -----------------------------------------------------------------
226   Status FinalizeLaunch(LaunchFlavor launch_flavor, MainLoop &main_loop);
227 
228   Status SaveExceptionPortInfo();
229 
230   void ExceptionMessageReceived(const MachException::Message &message);
231 
232   void MaybeRaiseThreadPriority();
233 
234   Status StartExceptionThread();
235 
236   Status SendInferiorExitStatusToMainLoop(::pid_t pid, int status);
237 
238   Status HandleWaitpidResult();
239 
240   bool ProcessUsingSpringBoard() const;
241 
242   bool ProcessUsingBackBoard() const;
243 
244   static void *ExceptionThread(void *arg);
245 
246   void *DoExceptionThread();
247 
248   lldb::addr_t GetDYLDAllImageInfosAddress(Status &error) const;
249 
250   static uint32_t GetCPUTypeForLocalProcess(::pid_t pid);
251 
252   uint32_t GetCPUType() const;
253 
254   task_t ExceptionMessageBundleComplete();
255 
256   void StartSTDIOThread();
257 
258   Status StartWaitpidThread(MainLoop &main_loop);
259 
260   static void *WaitpidThread(void *arg);
261 
262   void *DoWaitpidThread();
263 
264   task_t TaskPortForProcessID(Status &error, bool force = false) const;
265 
266   /// Attaches to an existing process.  Forms the
267   /// implementation of Process::DoAttach.
268   void AttachToInferior(MainLoop &mainloop, lldb::pid_t pid, Status &error);
269 
270   ::pid_t Attach(lldb::pid_t pid, Status &error);
271 
272   Status PrivateResume();
273 
274   Status ReplyToAllExceptions();
275 
276   Status ResumeTask();
277 
278   bool IsTaskValid() const;
279 
280   bool IsTaskValid(task_t task) const;
281 
282   mach_port_t GetExceptionPort() const;
283 
284   bool IsExceptionPortValid() const;
285 
286   Status GetTaskBasicInfo(task_t task, struct task_basic_info *info) const;
287 
288   Status SuspendTask();
289 
290   static Status SetDefaultPtraceOpts(const lldb::pid_t);
291 
292   static void *MonitorThread(void *baton);
293 
294   void MonitorCallback(lldb::pid_t pid, bool exited, int signal, int status);
295 
296   void WaitForNewThread(::pid_t tid);
297 
298   void MonitorSIGTRAP(const siginfo_t &info, NativeThreadDarwin &thread);
299 
300   void MonitorTrace(NativeThreadDarwin &thread);
301 
302   void MonitorBreakpoint(NativeThreadDarwin &thread);
303 
304   void MonitorWatchpoint(NativeThreadDarwin &thread, uint32_t wp_index);
305 
306   void MonitorSignal(const siginfo_t &info, NativeThreadDarwin &thread,
307                      bool exited);
308 
309   Status SetupSoftwareSingleStepping(NativeThreadDarwin &thread);
310 
311   bool HasThreadNoLock(lldb::tid_t thread_id);
312 
313   bool StopTrackingThread(lldb::tid_t thread_id);
314 
315   NativeThreadDarwinSP AddThread(lldb::tid_t thread_id);
316 
317   Status GetSoftwareBreakpointPCOffset(uint32_t &actual_opcode_size);
318 
319   Status FixupBreakpointPCAsNeeded(NativeThreadDarwin &thread);
320 
321   /// Writes a siginfo_t structure corresponding to the given thread
322   /// ID to the memory region pointed to by @p siginfo.
323   Status GetSignalInfo(lldb::tid_t tid, void *siginfo);
324 
325   /// Writes the raw event message code (vis-a-vis PTRACE_GETEVENTMSG)
326   /// corresponding to the given thread ID to the memory pointed to
327   /// by @p message.
328   Status GetEventMessage(lldb::tid_t tid, unsigned long *message);
329 
330   void NotifyThreadDeath(lldb::tid_t tid);
331 
332   Status Detach(lldb::tid_t tid);
333 
334   // This method is requests a stop on all threads which are still
335   // running. It sets up a deferred delegate notification, which will
336   // fire once threads report as stopped. The triggerring_tid will be
337   // set as the current thread (main stop reason).
338   void StopRunningThreads(lldb::tid_t triggering_tid);
339 
340   // Notify the delegate if all threads have stopped.
341   void SignalIfAllThreadsStopped();
342 
343   // Resume the given thread, optionally passing it the given signal.
344   // The type of resume operation (continue, single-step) depends on
345   // the state parameter.
346   Status ResumeThread(NativeThreadDarwin &thread, lldb::StateType state,
347                       int signo);
348 
349   void ThreadWasCreated(NativeThreadDarwin &thread);
350 
351   void SigchldHandler();
352 };
353 
354 } // namespace process_darwin
355 } // namespace lldb_private
356 
357 #endif /* NativeProcessDarwin_h */
358