xref: /llvm-project/lldb/source/Plugins/OperatingSystem/Python/OperatingSystemPython.cpp (revision 2833321f09efd9387257d17a3ef5128841142e6f)
1 //===-- OperatingSystemPython.cpp --------------------------------*- 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 LLDB_DISABLE_PYTHON
11 
12 #include "OperatingSystemPython.h"
13 // C Includes
14 // C++ Includes
15 // Other libraries and framework includes
16 #include "Plugins/Process/Utility/DynamicRegisterInfo.h"
17 #include "Plugins/Process/Utility/RegisterContextDummy.h"
18 #include "Plugins/Process/Utility/RegisterContextMemory.h"
19 #include "Plugins/Process/Utility/ThreadMemory.h"
20 #include "lldb/Core/ArchSpec.h"
21 #include "lldb/Core/Debugger.h"
22 #include "lldb/Core/Module.h"
23 #include "lldb/Core/PluginManager.h"
24 #include "lldb/Core/RegisterValue.h"
25 #include "lldb/Core/StructuredData.h"
26 #include "lldb/Core/ValueObjectVariable.h"
27 #include "lldb/Interpreter/CommandInterpreter.h"
28 #include "lldb/Interpreter/ScriptInterpreter.h"
29 #include "lldb/Symbol/ObjectFile.h"
30 #include "lldb/Symbol/VariableList.h"
31 #include "lldb/Target/Process.h"
32 #include "lldb/Target/StopInfo.h"
33 #include "lldb/Target/Target.h"
34 #include "lldb/Target/Thread.h"
35 #include "lldb/Target/ThreadList.h"
36 #include "lldb/Utility/DataBufferHeap.h"
37 #include "lldb/Utility/StreamString.h"
38 
39 using namespace lldb;
40 using namespace lldb_private;
41 
42 void OperatingSystemPython::Initialize() {
43   PluginManager::RegisterPlugin(GetPluginNameStatic(),
44                                 GetPluginDescriptionStatic(), CreateInstance,
45                                 nullptr);
46 }
47 
48 void OperatingSystemPython::Terminate() {
49   PluginManager::UnregisterPlugin(CreateInstance);
50 }
51 
52 OperatingSystem *OperatingSystemPython::CreateInstance(Process *process,
53                                                        bool force) {
54   // Python OperatingSystem plug-ins must be requested by name, so force must be
55   // true
56   FileSpec python_os_plugin_spec(process->GetPythonOSPluginPath());
57   if (python_os_plugin_spec && python_os_plugin_spec.Exists()) {
58     std::unique_ptr<OperatingSystemPython> os_ap(
59         new OperatingSystemPython(process, python_os_plugin_spec));
60     if (os_ap.get() && os_ap->IsValid())
61       return os_ap.release();
62   }
63   return NULL;
64 }
65 
66 ConstString OperatingSystemPython::GetPluginNameStatic() {
67   static ConstString g_name("python");
68   return g_name;
69 }
70 
71 const char *OperatingSystemPython::GetPluginDescriptionStatic() {
72   return "Operating system plug-in that gathers OS information from a python "
73          "class that implements the necessary OperatingSystem functionality.";
74 }
75 
76 OperatingSystemPython::OperatingSystemPython(lldb_private::Process *process,
77                                              const FileSpec &python_module_path)
78     : OperatingSystem(process), m_thread_list_valobj_sp(), m_register_info_ap(),
79       m_interpreter(NULL), m_python_object_sp() {
80   if (!process)
81     return;
82   TargetSP target_sp = process->CalculateTarget();
83   if (!target_sp)
84     return;
85   m_interpreter =
86       target_sp->GetDebugger().GetCommandInterpreter().GetScriptInterpreter();
87   if (m_interpreter) {
88 
89     std::string os_plugin_class_name(
90         python_module_path.GetFilename().AsCString(""));
91     if (!os_plugin_class_name.empty()) {
92       const bool init_session = false;
93       const bool allow_reload = true;
94       char python_module_path_cstr[PATH_MAX];
95       python_module_path.GetPath(python_module_path_cstr,
96                                  sizeof(python_module_path_cstr));
97       Status error;
98       if (m_interpreter->LoadScriptingModule(
99               python_module_path_cstr, allow_reload, init_session, error)) {
100         // Strip the ".py" extension if there is one
101         size_t py_extension_pos = os_plugin_class_name.rfind(".py");
102         if (py_extension_pos != std::string::npos)
103           os_plugin_class_name.erase(py_extension_pos);
104         // Add ".OperatingSystemPlugIn" to the module name to get a string like
105         // "modulename.OperatingSystemPlugIn"
106         os_plugin_class_name += ".OperatingSystemPlugIn";
107         StructuredData::ObjectSP object_sp =
108             m_interpreter->OSPlugin_CreatePluginObject(
109                 os_plugin_class_name.c_str(), process->CalculateProcess());
110         if (object_sp && object_sp->IsValid())
111           m_python_object_sp = object_sp;
112       }
113     }
114   }
115 }
116 
117 OperatingSystemPython::~OperatingSystemPython() {}
118 
119 DynamicRegisterInfo *OperatingSystemPython::GetDynamicRegisterInfo() {
120   if (m_register_info_ap.get() == NULL) {
121     if (!m_interpreter || !m_python_object_sp)
122       return NULL;
123     Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_OS));
124 
125     if (log)
126       log->Printf("OperatingSystemPython::GetDynamicRegisterInfo() fetching "
127                   "thread register definitions from python for pid %" PRIu64,
128                   m_process->GetID());
129 
130     StructuredData::DictionarySP dictionary =
131         m_interpreter->OSPlugin_RegisterInfo(m_python_object_sp);
132     if (!dictionary)
133       return NULL;
134 
135     m_register_info_ap.reset(new DynamicRegisterInfo(
136         *dictionary, m_process->GetTarget().GetArchitecture()));
137     assert(m_register_info_ap->GetNumRegisters() > 0);
138     assert(m_register_info_ap->GetNumRegisterSets() > 0);
139   }
140   return m_register_info_ap.get();
141 }
142 
143 //------------------------------------------------------------------
144 // PluginInterface protocol
145 //------------------------------------------------------------------
146 ConstString OperatingSystemPython::GetPluginName() {
147   return GetPluginNameStatic();
148 }
149 
150 uint32_t OperatingSystemPython::GetPluginVersion() { return 1; }
151 
152 bool OperatingSystemPython::UpdateThreadList(ThreadList &old_thread_list,
153                                              ThreadList &core_thread_list,
154                                              ThreadList &new_thread_list) {
155   if (!m_interpreter || !m_python_object_sp)
156     return false;
157 
158   Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_OS));
159 
160   // First thing we have to do is to try to get the API lock, and the run lock.
161   // We're going to change the thread content of the process, and we're going
162   // to use python, which requires the API lock to do it.
163   //
164   // If someone already has the API lock, that is ok, we just want to avoid
165   // external code from making new API calls while this call is happening.
166   //
167   // This is a recursive lock so we can grant it to any Python code called on
168   // the stack below us.
169   Target &target = m_process->GetTarget();
170   std::unique_lock<std::recursive_mutex> lock(target.GetAPIMutex(),
171                                               std::defer_lock);
172   lock.try_lock();
173 
174   if (log)
175     log->Printf("OperatingSystemPython::UpdateThreadList() fetching thread "
176                 "data from python for pid %" PRIu64,
177                 m_process->GetID());
178 
179   // The threads that are in "new_thread_list" upon entry are the threads from
180   // the
181   // lldb_private::Process subclass, no memory threads will be in this list.
182 
183   auto interpreter_lock =
184       m_interpreter
185           ->AcquireInterpreterLock(); // to make sure threads_list stays alive
186   StructuredData::ArraySP threads_list =
187       m_interpreter->OSPlugin_ThreadsInfo(m_python_object_sp);
188 
189   const uint32_t num_cores = core_thread_list.GetSize(false);
190 
191   // Make a map so we can keep track of which cores were used from the
192   // core_thread list. Any real threads/cores that weren't used should
193   // later be put back into the "new_thread_list".
194   std::vector<bool> core_used_map(num_cores, false);
195   if (threads_list) {
196     if (log) {
197       StreamString strm;
198       threads_list->Dump(strm);
199       log->Printf("threads_list = %s", strm.GetData());
200     }
201 
202     const uint32_t num_threads = threads_list->GetSize();
203     for (uint32_t i = 0; i < num_threads; ++i) {
204       StructuredData::ObjectSP thread_dict_obj =
205           threads_list->GetItemAtIndex(i);
206       if (auto thread_dict = thread_dict_obj->GetAsDictionary()) {
207         ThreadSP thread_sp(
208             CreateThreadFromThreadInfo(*thread_dict, core_thread_list,
209                                        old_thread_list, core_used_map, NULL));
210         if (thread_sp)
211           new_thread_list.AddThread(thread_sp);
212       }
213     }
214   }
215 
216   // Any real core threads that didn't end up backing a memory thread should
217   // still be in the main thread list, and they should be inserted at the
218   // beginning
219   // of the list
220   uint32_t insert_idx = 0;
221   for (uint32_t core_idx = 0; core_idx < num_cores; ++core_idx) {
222     if (core_used_map[core_idx] == false) {
223       new_thread_list.InsertThread(
224           core_thread_list.GetThreadAtIndex(core_idx, false), insert_idx);
225       ++insert_idx;
226     }
227   }
228 
229   return new_thread_list.GetSize(false) > 0;
230 }
231 
232 ThreadSP OperatingSystemPython::CreateThreadFromThreadInfo(
233     StructuredData::Dictionary &thread_dict, ThreadList &core_thread_list,
234     ThreadList &old_thread_list, std::vector<bool> &core_used_map,
235     bool *did_create_ptr) {
236   ThreadSP thread_sp;
237   tid_t tid = LLDB_INVALID_THREAD_ID;
238   if (!thread_dict.GetValueForKeyAsInteger("tid", tid))
239     return ThreadSP();
240 
241   uint32_t core_number;
242   addr_t reg_data_addr;
243   llvm::StringRef name;
244   llvm::StringRef queue;
245 
246   thread_dict.GetValueForKeyAsInteger("core", core_number, UINT32_MAX);
247   thread_dict.GetValueForKeyAsInteger("register_data_addr", reg_data_addr,
248                                       LLDB_INVALID_ADDRESS);
249   thread_dict.GetValueForKeyAsString("name", name);
250   thread_dict.GetValueForKeyAsString("queue", queue);
251 
252   // See if a thread already exists for "tid"
253   thread_sp = old_thread_list.FindThreadByID(tid, false);
254   if (thread_sp) {
255     // A thread already does exist for "tid", make sure it was an operating
256     // system
257     // plug-in generated thread.
258     if (!IsOperatingSystemPluginThread(thread_sp)) {
259       // We have thread ID overlap between the protocol threads and the
260       // operating system threads, clear the thread so we create an
261       // operating system thread for this.
262       thread_sp.reset();
263     }
264   }
265 
266   if (!thread_sp) {
267     if (did_create_ptr)
268       *did_create_ptr = true;
269     thread_sp.reset(
270         new ThreadMemory(*m_process, tid, name, queue, reg_data_addr));
271   }
272 
273   if (core_number < core_thread_list.GetSize(false)) {
274     ThreadSP core_thread_sp(
275         core_thread_list.GetThreadAtIndex(core_number, false));
276     if (core_thread_sp) {
277       // Keep track of which cores were set as the backing thread for memory
278       // threads...
279       if (core_number < core_used_map.size())
280         core_used_map[core_number] = true;
281 
282       ThreadSP backing_core_thread_sp(core_thread_sp->GetBackingThread());
283       if (backing_core_thread_sp) {
284         thread_sp->SetBackingThread(backing_core_thread_sp);
285       } else {
286         thread_sp->SetBackingThread(core_thread_sp);
287       }
288     }
289   }
290   return thread_sp;
291 }
292 
293 void OperatingSystemPython::ThreadWasSelected(Thread *thread) {}
294 
295 RegisterContextSP
296 OperatingSystemPython::CreateRegisterContextForThread(Thread *thread,
297                                                       addr_t reg_data_addr) {
298   RegisterContextSP reg_ctx_sp;
299   if (!m_interpreter || !m_python_object_sp || !thread)
300     return reg_ctx_sp;
301 
302   if (!IsOperatingSystemPluginThread(thread->shared_from_this()))
303     return reg_ctx_sp;
304 
305   // First thing we have to do is get the API lock, and the run lock.  We're
306   // going to change the thread
307   // content of the process, and we're going to use python, which requires the
308   // API lock to do it.
309   // So get & hold that.  This is a recursive lock so we can grant it to any
310   // Python code called on the stack below us.
311   Target &target = m_process->GetTarget();
312   std::lock_guard<std::recursive_mutex> guard(target.GetAPIMutex());
313 
314   Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_THREAD));
315 
316   auto lock =
317       m_interpreter
318           ->AcquireInterpreterLock(); // to make sure python objects stays alive
319   if (reg_data_addr != LLDB_INVALID_ADDRESS) {
320     // The registers data is in contiguous memory, just create the register
321     // context using the address provided
322     if (log)
323       log->Printf("OperatingSystemPython::CreateRegisterContextForThread (tid "
324                   "= 0x%" PRIx64 ", 0x%" PRIx64 ", reg_data_addr = 0x%" PRIx64
325                   ") creating memory register context",
326                   thread->GetID(), thread->GetProtocolID(), reg_data_addr);
327     reg_ctx_sp.reset(new RegisterContextMemory(
328         *thread, 0, *GetDynamicRegisterInfo(), reg_data_addr));
329   } else {
330     // No register data address is provided, query the python plug-in to let
331     // it make up the data as it sees fit
332     if (log)
333       log->Printf("OperatingSystemPython::CreateRegisterContextForThread (tid "
334                   "= 0x%" PRIx64 ", 0x%" PRIx64
335                   ") fetching register data from python",
336                   thread->GetID(), thread->GetProtocolID());
337 
338     StructuredData::StringSP reg_context_data =
339         m_interpreter->OSPlugin_RegisterContextData(m_python_object_sp,
340                                                     thread->GetID());
341     if (reg_context_data) {
342       std::string value = reg_context_data->GetValue();
343       DataBufferSP data_sp(new DataBufferHeap(value.c_str(), value.length()));
344       if (data_sp->GetByteSize()) {
345         RegisterContextMemory *reg_ctx_memory = new RegisterContextMemory(
346             *thread, 0, *GetDynamicRegisterInfo(), LLDB_INVALID_ADDRESS);
347         if (reg_ctx_memory) {
348           reg_ctx_sp.reset(reg_ctx_memory);
349           reg_ctx_memory->SetAllRegisterData(data_sp);
350         }
351       }
352     }
353   }
354   // if we still have no register data, fallback on a dummy context to avoid
355   // crashing
356   if (!reg_ctx_sp) {
357     if (log)
358       log->Printf("OperatingSystemPython::CreateRegisterContextForThread (tid "
359                   "= 0x%" PRIx64 ") forcing a dummy register context",
360                   thread->GetID());
361     reg_ctx_sp.reset(new RegisterContextDummy(
362         *thread, 0, target.GetArchitecture().GetAddressByteSize()));
363   }
364   return reg_ctx_sp;
365 }
366 
367 StopInfoSP
368 OperatingSystemPython::CreateThreadStopReason(lldb_private::Thread *thread) {
369   // We should have gotten the thread stop info from the dictionary of data for
370   // the thread in the initial call to get_thread_info(), this should have been
371   // cached so we can return it here
372   StopInfoSP
373       stop_info_sp; //(StopInfo::CreateStopReasonWithSignal (*thread, SIGSTOP));
374   return stop_info_sp;
375 }
376 
377 lldb::ThreadSP OperatingSystemPython::CreateThread(lldb::tid_t tid,
378                                                    addr_t context) {
379   Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_THREAD));
380 
381   if (log)
382     log->Printf("OperatingSystemPython::CreateThread (tid = 0x%" PRIx64
383                 ", context = 0x%" PRIx64 ") fetching register data from python",
384                 tid, context);
385 
386   if (m_interpreter && m_python_object_sp) {
387     // First thing we have to do is get the API lock, and the run lock.  We're
388     // going to change the thread
389     // content of the process, and we're going to use python, which requires the
390     // API lock to do it.
391     // So get & hold that.  This is a recursive lock so we can grant it to any
392     // Python code called on the stack below us.
393     Target &target = m_process->GetTarget();
394     std::lock_guard<std::recursive_mutex> guard(target.GetAPIMutex());
395 
396     auto lock = m_interpreter->AcquireInterpreterLock(); // to make sure
397                                                          // thread_info_dict
398                                                          // stays alive
399     StructuredData::DictionarySP thread_info_dict =
400         m_interpreter->OSPlugin_CreateThread(m_python_object_sp, tid, context);
401     std::vector<bool> core_used_map;
402     if (thread_info_dict) {
403       ThreadList core_threads(m_process);
404       ThreadList &thread_list = m_process->GetThreadList();
405       bool did_create = false;
406       ThreadSP thread_sp(
407           CreateThreadFromThreadInfo(*thread_info_dict, core_threads,
408                                      thread_list, core_used_map, &did_create));
409       if (did_create)
410         thread_list.AddThread(thread_sp);
411       return thread_sp;
412     }
413   }
414   return ThreadSP();
415 }
416 
417 #endif // #ifndef LLDB_DISABLE_PYTHON
418