xref: /llvm-project/lldb/source/Plugins/Process/Linux/NativeProcessLinux.h (revision e64cc756819d567f453467bf7cc16599ad296fdd)
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 #include "llvm/ADT/SmallPtrSet.h"
23 
24 #include "IntelPTCollector.h"
25 #include "NativeThreadLinux.h"
26 #include "Plugins/Process/POSIX/NativeProcessELF.h"
27 #include "Plugins/Process/Utility/NativeProcessSoftwareSingleStep.h"
28 
29 namespace lldb_private {
30 class Status;
31 class Scalar;
32 
33 namespace process_linux {
34 /// \class NativeProcessLinux
35 /// Manages communication with the inferior (debugee) process.
36 ///
37 /// Upon construction, this class prepares and launches an inferior process
38 /// for debugging.
39 ///
40 /// Changes in the inferior process state are broadcasted.
41 class NativeProcessLinux : public NativeProcessELF,
42                            private NativeProcessSoftwareSingleStep {
43 public:
44   class Manager : public NativeProcessProtocol::Manager {
45   public:
46     Manager(MainLoop &mainloop);
47 
48     llvm::Expected<std::unique_ptr<NativeProcessProtocol>>
49     Launch(ProcessLaunchInfo &launch_info,
50            NativeDelegate &native_delegate) override;
51 
52     llvm::Expected<std::unique_ptr<NativeProcessProtocol>>
53     Attach(lldb::pid_t pid, NativeDelegate &native_delegate) override;
54 
55     Extension GetSupportedExtensions() const override;
56 
AddProcess(NativeProcessLinux & process)57     void AddProcess(NativeProcessLinux &process) {
58       m_processes.insert(&process);
59     }
60 
RemoveProcess(NativeProcessLinux & process)61     void RemoveProcess(NativeProcessLinux &process) {
62       m_processes.erase(&process);
63     }
64 
65     // Collect an event for the given tid, waiting for it if necessary.
66     void CollectThread(::pid_t tid);
67 
68   private:
69     MainLoop::SignalHandleUP m_sigchld_handle;
70 
71     llvm::SmallPtrSet<NativeProcessLinux *, 2> m_processes;
72 
73     // Threads (events) which haven't been claimed by any process.
74     llvm::DenseSet<::pid_t> m_unowned_threads;
75 
76     void SigchldHandler();
77   };
78 
79   // NativeProcessProtocol Interface
80 
~NativeProcessLinux()81   ~NativeProcessLinux() override { m_manager.RemoveProcess(*this); }
82 
83   Status Resume(const ResumeActionList &resume_actions) override;
84 
85   Status Halt() override;
86 
87   Status Detach() override;
88 
89   Status Signal(int signo) override;
90 
91   Status Interrupt() override;
92 
93   Status Kill() override;
94 
95   Status GetMemoryRegionInfo(lldb::addr_t load_addr,
96                              MemoryRegionInfo &range_info) override;
97 
98   Status ReadMemory(lldb::addr_t addr, void *buf, size_t size,
99                     size_t &bytes_read) override;
100 
101   Status WriteMemory(lldb::addr_t addr, const void *buf, size_t size,
102                      size_t &bytes_written) override;
103 
104   llvm::Expected<lldb::addr_t> AllocateMemory(size_t size,
105                                               uint32_t permissions) override;
106 
107   llvm::Error DeallocateMemory(lldb::addr_t addr) override;
108 
109   Status ReadMemoryTags(int32_t type, lldb::addr_t addr, size_t len,
110                         std::vector<uint8_t> &tags) override;
111 
112   Status WriteMemoryTags(int32_t type, lldb::addr_t addr, size_t len,
113                          const std::vector<uint8_t> &tags) override;
114 
115   size_t UpdateThreads() override;
116 
GetArchitecture()117   const ArchSpec &GetArchitecture() const override { return m_arch; }
118 
119   Status SetBreakpoint(lldb::addr_t addr, uint32_t size,
120                        bool hardware) override;
121 
122   Status RemoveBreakpoint(lldb::addr_t addr, bool hardware = false) override;
123 
124   void DoStopIDBumped(uint32_t newBumpId) override;
125 
126   Status GetLoadedModuleFileSpec(const char *module_path,
127                                  FileSpec &file_spec) override;
128 
129   Status GetFileLoadAddress(const llvm::StringRef &file_name,
130                             lldb::addr_t &load_addr) override;
131 
132   NativeThreadLinux *GetThreadByID(lldb::tid_t id);
133   NativeThreadLinux *GetCurrentThread();
134 
135   llvm::ErrorOr<std::unique_ptr<llvm::MemoryBuffer>>
GetAuxvData()136   GetAuxvData() const override {
137     return getProcFile(GetID(), "auxv");
138   }
139 
140   /// Tracing
141   /// These methods implement the jLLDBTrace packets
142   /// \{
143   llvm::Error TraceStart(llvm::StringRef json_request,
144                          llvm::StringRef type) override;
145 
146   llvm::Error TraceStop(const TraceStopRequest &request) override;
147 
148   llvm::Expected<llvm::json::Value>
149   TraceGetState(llvm::StringRef type) override;
150 
151   llvm::Expected<std::vector<uint8_t>>
152   TraceGetBinaryData(const TraceGetBinaryDataRequest &request) override;
153 
154   llvm::Expected<TraceSupportedResponse> TraceSupported() override;
155   /// }
156 
157   // Interface used by NativeRegisterContext-derived classes.
158   static Status PtraceWrapper(int req, lldb::pid_t pid, void *addr = nullptr,
159                               void *data = nullptr, size_t data_size = 0,
160                               long *result = nullptr);
161 
162   bool SupportHardwareSingleStepping() const;
163 
164   /// Writes a siginfo_t structure corresponding to the given thread ID to the
165   /// memory region pointed to by \p siginfo.
166   Status GetSignalInfo(lldb::tid_t tid, void *siginfo) const;
167 
168 protected:
169   llvm::Expected<llvm::ArrayRef<uint8_t>>
170   GetSoftwareBreakpointTrapOpcode(size_t size_hint) override;
171 
172   llvm::Expected<uint64_t> Syscall(llvm::ArrayRef<uint64_t> args);
173 
174 private:
175   Manager &m_manager;
176   ArchSpec m_arch;
177 
178   LazyBool m_supports_mem_region = eLazyBoolCalculate;
179   std::vector<std::pair<MemoryRegionInfo, FileSpec>> m_mem_region_cache;
180 
181   lldb::tid_t m_pending_notification_tid = LLDB_INVALID_THREAD_ID;
182 
183   /// Inferior memory (allocated by us) and its size.
184   llvm::DenseMap<lldb::addr_t, lldb::addr_t> m_allocated_memory;
185 
186   // Private Instance Methods
187   NativeProcessLinux(::pid_t pid, int terminal_fd, NativeDelegate &delegate,
188                      const ArchSpec &arch, Manager &manager,
189                      llvm::ArrayRef<::pid_t> tids);
190 
191   // Returns a list of process threads that we have attached to.
192   static llvm::Expected<std::vector<::pid_t>> Attach(::pid_t pid);
193 
194   static Status SetDefaultPtraceOpts(const lldb::pid_t);
195 
196   bool TryHandleWaitStatus(lldb::pid_t pid, WaitStatus status);
197 
198   void MonitorCallback(NativeThreadLinux &thread, WaitStatus status);
199 
200   void MonitorSIGTRAP(const siginfo_t &info, NativeThreadLinux &thread);
201 
202   void MonitorTrace(NativeThreadLinux &thread);
203 
204   void MonitorBreakpoint(NativeThreadLinux &thread);
205 
206   void MonitorWatchpoint(NativeThreadLinux &thread, uint32_t wp_index);
207 
208   void MonitorSignal(const siginfo_t &info, NativeThreadLinux &thread);
209 
210   bool HasThreadNoLock(lldb::tid_t thread_id);
211 
212   void StopTrackingThread(NativeThreadLinux &thread);
213 
214   /// Create a new thread.
215   ///
216   /// If process tracing is enabled and the thread can't be traced, then the
217   /// thread is left stopped with a \a eStopReasonProcessorTrace status, and
218   /// then the process is stopped.
219   ///
220   /// \param[in] resume
221   ///     If a tracing error didn't happen, then resume the thread after
222   ///     creation if \b true, or leave it stopped with SIGSTOP if \b false.
223   NativeThreadLinux &AddThread(lldb::tid_t thread_id, bool resume);
224 
225   /// Start tracing a new thread if process tracing is enabled.
226   ///
227   /// Trace mechanisms should modify this method to provide automatic tracing
228   /// for new threads.
229   Status NotifyTracersOfNewThread(lldb::tid_t tid);
230 
231   /// Stop tracing threads upon a destroy event.
232   ///
233   /// Trace mechanisms should modify this method to provide automatic trace
234   /// stopping for threads being destroyed.
235   Status NotifyTracersOfThreadDestroyed(lldb::tid_t tid);
236 
237   void NotifyTracersProcessWillResume() override;
238 
239   void NotifyTracersProcessDidStop() override;
240 
241   /// Writes the raw event message code (vis-a-vis PTRACE_GETEVENTMSG)
242   /// corresponding to the given thread ID to the memory pointed to by @p
243   /// message.
244   Status GetEventMessage(lldb::tid_t tid, unsigned long *message);
245 
246   void NotifyThreadDeath(lldb::tid_t tid);
247 
248   Status Detach(lldb::tid_t tid);
249 
250   // This method is requests a stop on all threads which are still running. It
251   // sets up a
252   // deferred delegate notification, which will fire once threads report as
253   // stopped. The
254   // triggerring_tid will be set as the current thread (main stop reason).
255   void StopRunningThreads(lldb::tid_t triggering_tid);
256 
257   // Notify the delegate if all threads have stopped.
258   void SignalIfAllThreadsStopped();
259 
260   // Resume the given thread, optionally passing it the given signal. The type
261   // of resume
262   // operation (continue, single-step) depends on the state parameter.
263   Status ResumeThread(NativeThreadLinux &thread, lldb::StateType state,
264                       int signo);
265 
266   void ThreadWasCreated(NativeThreadLinux &thread);
267 
268   void SigchldHandler();
269 
270   Status PopulateMemoryRegionCache();
271 
272   /// Manages Intel PT process and thread traces.
273   IntelPTCollector m_intel_pt_collector;
274 
275   // Handle a clone()-like event.
276   bool MonitorClone(NativeThreadLinux &parent, lldb::pid_t child_pid,
277                     int event);
278 };
279 
280 } // namespace process_linux
281 } // namespace lldb_private
282 
283 #endif // #ifndef liblldb_NativeProcessLinux_H_
284