1 //===-- NativeProcessLinux.h ---------------------------------- -*- C++ -*-===//
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 #ifndef liblldb_NativeProcessLinux_H_
10 #define liblldb_NativeProcessLinux_H_
11 
12 #include <csignal>
13 #include <unordered_set>
14 
15 #include "lldb/Host/Debug.h"
16 #include "lldb/Host/HostThread.h"
17 #include "lldb/Host/linux/Support.h"
18 #include "lldb/Target/MemoryRegionInfo.h"
19 #include "lldb/Utility/ArchSpec.h"
20 #include "lldb/Utility/FileSpec.h"
21 #include "lldb/lldb-types.h"
22 
23 #include "IntelPTManager.h"
24 #include "NativeThreadLinux.h"
25 #include "Plugins/Process/POSIX/NativeProcessELF.h"
26 #include "Plugins/Process/Utility/NativeProcessSoftwareSingleStep.h"
27 
28 namespace lldb_private {
29 class Status;
30 class Scalar;
31 
32 namespace process_linux {
33 /// \class NativeProcessLinux
34 /// Manages communication with the inferior (debugee) process.
35 ///
36 /// Upon construction, this class prepares and launches an inferior process
37 /// for debugging.
38 ///
39 /// Changes in the inferior process state are broadcasted.
40 class NativeProcessLinux : public NativeProcessELF,
41                            private NativeProcessSoftwareSingleStep {
42 public:
43   class Factory : public NativeProcessProtocol::Factory {
44   public:
45     llvm::Expected<std::unique_ptr<NativeProcessProtocol>>
46     Launch(ProcessLaunchInfo &launch_info, NativeDelegate &native_delegate,
47            MainLoop &mainloop) const override;
48 
49     llvm::Expected<std::unique_ptr<NativeProcessProtocol>>
50     Attach(lldb::pid_t pid, NativeDelegate &native_delegate,
51            MainLoop &mainloop) const override;
52   };
53 
54   // NativeProcessProtocol Interface
55   Status Resume(const ResumeActionList &resume_actions) override;
56 
57   Status Halt() override;
58 
59   Status Detach() override;
60 
61   Status Signal(int signo) override;
62 
63   Status Interrupt() override;
64 
65   Status Kill() override;
66 
67   Status GetMemoryRegionInfo(lldb::addr_t load_addr,
68                              MemoryRegionInfo &range_info) override;
69 
70   Status ReadMemory(lldb::addr_t addr, void *buf, size_t size,
71                     size_t &bytes_read) override;
72 
73   Status WriteMemory(lldb::addr_t addr, const void *buf, size_t size,
74                      size_t &bytes_written) override;
75 
76   llvm::Expected<lldb::addr_t> AllocateMemory(size_t size,
77                                               uint32_t permissions) override;
78 
79   llvm::Error DeallocateMemory(lldb::addr_t addr) override;
80 
81   size_t UpdateThreads() override;
82 
83   const ArchSpec &GetArchitecture() const override { return m_arch; }
84 
85   Status SetBreakpoint(lldb::addr_t addr, uint32_t size,
86                        bool hardware) override;
87 
88   Status RemoveBreakpoint(lldb::addr_t addr, bool hardware = false) override;
89 
90   void DoStopIDBumped(uint32_t newBumpId) override;
91 
92   Status GetLoadedModuleFileSpec(const char *module_path,
93                                  FileSpec &file_spec) override;
94 
95   Status GetFileLoadAddress(const llvm::StringRef &file_name,
96                             lldb::addr_t &load_addr) override;
97 
98   NativeThreadLinux *GetThreadByID(lldb::tid_t id);
99   NativeThreadLinux *GetCurrentThread();
100 
101   llvm::ErrorOr<std::unique_ptr<llvm::MemoryBuffer>>
102   GetAuxvData() const override {
103     return getProcFile(GetID(), "auxv");
104   }
105 
106   /// Tracing
107   /// These methods implement the jLLDBTrace packets
108   /// \{
109   llvm::Error TraceStart(llvm::StringRef json_request,
110                          llvm::StringRef type) override;
111 
112   llvm::Error TraceStop(const TraceStopRequest &request) override;
113 
114   llvm::Expected<llvm::json::Value>
115   TraceGetState(llvm::StringRef type) override;
116 
117   llvm::Expected<std::vector<uint8_t>>
118   TraceGetBinaryData(const TraceGetBinaryDataRequest &request) override;
119 
120   llvm::Expected<TraceSupportedResponse> TraceSupported() override;
121   /// }
122 
123   // Interface used by NativeRegisterContext-derived classes.
124   static Status PtraceWrapper(int req, lldb::pid_t pid, void *addr = nullptr,
125                               void *data = nullptr, size_t data_size = 0,
126                               long *result = nullptr);
127 
128   bool SupportHardwareSingleStepping() const;
129 
130 protected:
131   llvm::Expected<llvm::ArrayRef<uint8_t>>
132   GetSoftwareBreakpointTrapOpcode(size_t size_hint) override;
133 
134   llvm::Expected<uint64_t> Syscall(llvm::ArrayRef<uint64_t> args);
135 
136 private:
137   MainLoop::SignalHandleUP m_sigchld_handle;
138   ArchSpec m_arch;
139 
140   LazyBool m_supports_mem_region = eLazyBoolCalculate;
141   std::vector<std::pair<MemoryRegionInfo, FileSpec>> m_mem_region_cache;
142 
143   lldb::tid_t m_pending_notification_tid = LLDB_INVALID_THREAD_ID;
144 
145   /// Inferior memory (allocated by us) and its size.
146   llvm::DenseMap<lldb::addr_t, lldb::addr_t> m_allocated_memory;
147 
148   // Private Instance Methods
149   NativeProcessLinux(::pid_t pid, int terminal_fd, NativeDelegate &delegate,
150                      const ArchSpec &arch, MainLoop &mainloop,
151                      llvm::ArrayRef<::pid_t> tids);
152 
153   // Returns a list of process threads that we have attached to.
154   static llvm::Expected<std::vector<::pid_t>> Attach(::pid_t pid);
155 
156   static Status SetDefaultPtraceOpts(const lldb::pid_t);
157 
158   void MonitorCallback(lldb::pid_t pid, bool exited, WaitStatus status);
159 
160   void WaitForCloneNotification(::pid_t pid);
161 
162   void MonitorSIGTRAP(const siginfo_t &info, NativeThreadLinux &thread);
163 
164   void MonitorTrace(NativeThreadLinux &thread);
165 
166   void MonitorBreakpoint(NativeThreadLinux &thread);
167 
168   void MonitorWatchpoint(NativeThreadLinux &thread, uint32_t wp_index);
169 
170   void MonitorSignal(const siginfo_t &info, NativeThreadLinux &thread,
171                      bool exited);
172 
173   bool HasThreadNoLock(lldb::tid_t thread_id);
174 
175   bool StopTrackingThread(lldb::tid_t thread_id);
176 
177   /// Create a new thread.
178   ///
179   /// If process tracing is enabled and the thread can't be traced, then the
180   /// thread is left stopped with a \a eStopReasonProcessorTrace status, and
181   /// then the process is stopped.
182   ///
183   /// \param[in] resume
184   ///     If a tracing error didn't happen, then resume the thread after
185   ///     creation if \b true, or leave it stopped with SIGSTOP if \b false.
186   NativeThreadLinux &AddThread(lldb::tid_t thread_id, bool resume);
187 
188   /// Start tracing a new thread if process tracing is enabled.
189   ///
190   /// Trace mechanisms should modify this method to provide automatic tracing
191   /// for new threads.
192   Status NotifyTracersOfNewThread(lldb::tid_t tid);
193 
194   /// Stop tracing threads upon a destroy event.
195   ///
196   /// Trace mechanisms should modify this method to provide automatic trace
197   /// stopping for threads being destroyed.
198   Status NotifyTracersOfThreadDestroyed(lldb::tid_t tid);
199 
200   /// Writes a siginfo_t structure corresponding to the given thread ID to the
201   /// memory region pointed to by \p siginfo.
202   Status GetSignalInfo(lldb::tid_t tid, void *siginfo);
203 
204   /// Writes the raw event message code (vis-a-vis PTRACE_GETEVENTMSG)
205   /// corresponding to the given thread ID to the memory pointed to by @p
206   /// message.
207   Status GetEventMessage(lldb::tid_t tid, unsigned long *message);
208 
209   void NotifyThreadDeath(lldb::tid_t tid);
210 
211   Status Detach(lldb::tid_t tid);
212 
213   // This method is requests a stop on all threads which are still running. It
214   // sets up a
215   // deferred delegate notification, which will fire once threads report as
216   // stopped. The
217   // triggerring_tid will be set as the current thread (main stop reason).
218   void StopRunningThreads(lldb::tid_t triggering_tid);
219 
220   // Notify the delegate if all threads have stopped.
221   void SignalIfAllThreadsStopped();
222 
223   // Resume the given thread, optionally passing it the given signal. The type
224   // of resume
225   // operation (continue, single-step) depends on the state parameter.
226   Status ResumeThread(NativeThreadLinux &thread, lldb::StateType state,
227                       int signo);
228 
229   void ThreadWasCreated(NativeThreadLinux &thread);
230 
231   void SigchldHandler();
232 
233   Status PopulateMemoryRegionCache();
234 
235   /// Manages Intel PT process and thread traces.
236   IntelPTManager m_intel_pt_manager;
237 
238   struct CloneInfo {
239     int event;
240     lldb::tid_t parent_tid;
241   };
242 
243   // Map of child processes that have been signaled once, and we are
244   // waiting for the second signal.
245   llvm::DenseMap<lldb::pid_t, llvm::Optional<CloneInfo>> m_pending_pid_map;
246 
247   // Handle a clone()-like event.  If received by parent, clone_info contains
248   // additional info.  Returns true if the event is handled, or false if it
249   // is pending second notification.
250   bool MonitorClone(lldb::pid_t child_pid,
251                     llvm::Optional<CloneInfo> clone_info);
252 };
253 
254 } // namespace process_linux
255 } // namespace lldb_private
256 
257 #endif // #ifndef liblldb_NativeProcessLinux_H_
258