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 "NativeThreadLinux.h"
24 #include "Plugins/Process/POSIX/NativeProcessELF.h"
25 #include "Plugins/Process/Utility/NativeProcessSoftwareSingleStep.h"
26 #include "ProcessorTrace.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   lldb::user_id_t StartTrace(const TraceOptions &config,
107                              Status &error) override;
108 
109   Status StopTrace(lldb::user_id_t traceid,
110                    lldb::tid_t thread) override;
111 
112   Status GetData(lldb::user_id_t traceid, lldb::tid_t thread,
113                  llvm::MutableArrayRef<uint8_t> &buffer,
114                  size_t offset = 0) override;
115 
116   Status GetMetaData(lldb::user_id_t traceid, lldb::tid_t thread,
117                      llvm::MutableArrayRef<uint8_t> &buffer,
118                      size_t offset = 0) override;
119 
120   Status GetTraceConfig(lldb::user_id_t traceid, TraceOptions &config) override;
121 
122   virtual llvm::Expected<TraceTypeInfo> GetSupportedTraceType() override;
123 
124   // Interface used by NativeRegisterContext-derived classes.
125   static Status PtraceWrapper(int req, lldb::pid_t pid, void *addr = nullptr,
126                               void *data = nullptr, size_t data_size = 0,
127                               long *result = nullptr);
128 
129   bool SupportHardwareSingleStepping() const;
130 
131 protected:
132   llvm::Expected<llvm::ArrayRef<uint8_t>>
133   GetSoftwareBreakpointTrapOpcode(size_t size_hint) override;
134 
135   llvm::Expected<uint64_t> Syscall(llvm::ArrayRef<uint64_t> args);
136 
137 private:
138   MainLoop::SignalHandleUP m_sigchld_handle;
139   ArchSpec m_arch;
140 
141   LazyBool m_supports_mem_region = eLazyBoolCalculate;
142   std::vector<std::pair<MemoryRegionInfo, FileSpec>> m_mem_region_cache;
143 
144   lldb::tid_t m_pending_notification_tid = LLDB_INVALID_THREAD_ID;
145 
146   /// Inferior memory (allocated by us) and its size.
147   llvm::DenseMap<lldb::addr_t, lldb::addr_t> m_allocated_memory;
148 
149   // Private Instance Methods
150   NativeProcessLinux(::pid_t pid, int terminal_fd, NativeDelegate &delegate,
151                      const ArchSpec &arch, MainLoop &mainloop,
152                      llvm::ArrayRef<::pid_t> tids);
153 
154   // Returns a list of process threads that we have attached to.
155   static llvm::Expected<std::vector<::pid_t>> Attach(::pid_t pid);
156 
157   static Status SetDefaultPtraceOpts(const lldb::pid_t);
158 
159   void MonitorCallback(lldb::pid_t pid, bool exited, WaitStatus status);
160 
161   void WaitForNewThread(::pid_t tid);
162 
163   void MonitorSIGTRAP(const siginfo_t &info, NativeThreadLinux &thread);
164 
165   void MonitorTrace(NativeThreadLinux &thread);
166 
167   void MonitorBreakpoint(NativeThreadLinux &thread);
168 
169   void MonitorWatchpoint(NativeThreadLinux &thread, uint32_t wp_index);
170 
171   void MonitorSignal(const siginfo_t &info, NativeThreadLinux &thread,
172                      bool exited);
173 
174   bool HasThreadNoLock(lldb::tid_t thread_id);
175 
176   bool StopTrackingThread(lldb::tid_t thread_id);
177 
178   NativeThreadLinux &AddThread(lldb::tid_t thread_id);
179 
180   /// Writes a siginfo_t structure corresponding to the given thread ID to the
181   /// memory region pointed to by \p siginfo.
182   Status GetSignalInfo(lldb::tid_t tid, void *siginfo);
183 
184   /// Writes the raw event message code (vis-a-vis PTRACE_GETEVENTMSG)
185   /// corresponding to the given thread ID to the memory pointed to by @p
186   /// message.
187   Status GetEventMessage(lldb::tid_t tid, unsigned long *message);
188 
189   void NotifyThreadDeath(lldb::tid_t tid);
190 
191   Status Detach(lldb::tid_t tid);
192 
193   // This method is requests a stop on all threads which are still running. It
194   // sets up a
195   // deferred delegate notification, which will fire once threads report as
196   // stopped. The
197   // triggerring_tid will be set as the current thread (main stop reason).
198   void StopRunningThreads(lldb::tid_t triggering_tid);
199 
200   // Notify the delegate if all threads have stopped.
201   void SignalIfAllThreadsStopped();
202 
203   // Resume the given thread, optionally passing it the given signal. The type
204   // of resume
205   // operation (continue, single-step) depends on the state parameter.
206   Status ResumeThread(NativeThreadLinux &thread, lldb::StateType state,
207                       int signo);
208 
209   void ThreadWasCreated(NativeThreadLinux &thread);
210 
211   void SigchldHandler();
212 
213   Status PopulateMemoryRegionCache();
214 
215   lldb::user_id_t StartTraceGroup(const TraceOptions &config,
216                                          Status &error);
217 
218   // This function is intended to be used to stop tracing
219   // on a thread that exited.
220   Status StopTracingForThread(lldb::tid_t thread);
221 
222   // The below function as the name suggests, looks up a ProcessorTrace
223   // instance from the m_processor_trace_monitor map. In the case of
224   // process tracing where the traceid passed would map to the complete
225   // process, it is mandatory to provide a threadid to obtain a trace
226   // instance (since ProcessorTrace is tied to a thread). In the other
227   // scenario that an individual thread is being traced, just the traceid
228   // is sufficient to obtain the actual ProcessorTrace instance.
229   llvm::Expected<ProcessorTraceMonitor &>
230   LookupProcessorTraceInstance(lldb::user_id_t traceid, lldb::tid_t thread);
231 
232   // Stops tracing on individual threads being traced. Not intended
233   // to be used to stop tracing on complete process.
234   Status StopProcessorTracingOnThread(lldb::user_id_t traceid,
235                                       lldb::tid_t thread);
236 
237   // Intended to stop tracing on complete process.
238   // Should not be used for stopping trace on
239   // individual threads.
240   void StopProcessorTracingOnProcess();
241 
242   llvm::DenseMap<lldb::tid_t, ProcessorTraceMonitorUP>
243       m_processor_trace_monitor;
244 
245   // Set for tracking threads being traced under
246   // same process user id.
247   llvm::DenseSet<lldb::tid_t> m_pt_traced_thread_group;
248 
249   lldb::user_id_t m_pt_proces_trace_id = LLDB_INVALID_UID;
250   TraceOptions m_pt_process_trace_config;
251 };
252 
253 } // namespace process_linux
254 } // namespace lldb_private
255 
256 #endif // #ifndef liblldb_NativeProcessLinux_H_
257