xref: /llvm-project/lldb/source/Plugins/OperatingSystem/Python/OperatingSystemPython.cpp (revision b9c1b51e45b845debb76d8658edabca70ca56079)
1 //===-- OperatingSystemPython.cpp --------------------------------*- C++
2 //-*-===//
3 //
4 //                     The LLVM Compiler Infrastructure
5 //
6 // This file is distributed under the University of Illinois Open Source
7 // License. See LICENSE.TXT for details.
8 //
9 //===----------------------------------------------------------------------===//
10 
11 #ifndef LLDB_DISABLE_PYTHON
12 
13 #include "OperatingSystemPython.h"
14 // C Includes
15 // C++ Includes
16 // Other libraries and framework includes
17 #include "Plugins/Process/Utility/DynamicRegisterInfo.h"
18 #include "Plugins/Process/Utility/RegisterContextDummy.h"
19 #include "Plugins/Process/Utility/RegisterContextMemory.h"
20 #include "Plugins/Process/Utility/ThreadMemory.h"
21 #include "lldb/Core/ArchSpec.h"
22 #include "lldb/Core/DataBufferHeap.h"
23 #include "lldb/Core/Debugger.h"
24 #include "lldb/Core/Module.h"
25 #include "lldb/Core/PluginManager.h"
26 #include "lldb/Core/RegisterValue.h"
27 #include "lldb/Core/StreamString.h"
28 #include "lldb/Core/StructuredData.h"
29 #include "lldb/Core/ValueObjectVariable.h"
30 #include "lldb/Interpreter/CommandInterpreter.h"
31 #include "lldb/Interpreter/ScriptInterpreter.h"
32 #include "lldb/Symbol/ObjectFile.h"
33 #include "lldb/Symbol/VariableList.h"
34 #include "lldb/Target/Process.h"
35 #include "lldb/Target/StopInfo.h"
36 #include "lldb/Target/Target.h"
37 #include "lldb/Target/Thread.h"
38 #include "lldb/Target/ThreadList.h"
39 
40 using namespace lldb;
41 using namespace lldb_private;
42 
43 void OperatingSystemPython::Initialize() {
44   PluginManager::RegisterPlugin(GetPluginNameStatic(),
45                                 GetPluginDescriptionStatic(), CreateInstance,
46                                 nullptr);
47 }
48 
49 void OperatingSystemPython::Terminate() {
50   PluginManager::UnregisterPlugin(CreateInstance);
51 }
52 
53 OperatingSystem *OperatingSystemPython::CreateInstance(Process *process,
54                                                        bool force) {
55   // Python OperatingSystem plug-ins must be requested by name, so force must be
56   // true
57   FileSpec python_os_plugin_spec(process->GetPythonOSPluginPath());
58   if (python_os_plugin_spec && python_os_plugin_spec.Exists()) {
59     std::unique_ptr<OperatingSystemPython> os_ap(
60         new OperatingSystemPython(process, python_os_plugin_spec));
61     if (os_ap.get() && os_ap->IsValid())
62       return os_ap.release();
63   }
64   return NULL;
65 }
66 
67 ConstString OperatingSystemPython::GetPluginNameStatic() {
68   static ConstString g_name("python");
69   return g_name;
70 }
71 
72 const char *OperatingSystemPython::GetPluginDescriptionStatic() {
73   return "Operating system plug-in that gathers OS information from a python "
74          "class that implements the necessary OperatingSystem functionality.";
75 }
76 
77 OperatingSystemPython::OperatingSystemPython(lldb_private::Process *process,
78                                              const FileSpec &python_module_path)
79     : OperatingSystem(process), m_thread_list_valobj_sp(), m_register_info_ap(),
80       m_interpreter(NULL), m_python_object_sp() {
81   if (!process)
82     return;
83   TargetSP target_sp = process->CalculateTarget();
84   if (!target_sp)
85     return;
86   m_interpreter =
87       target_sp->GetDebugger().GetCommandInterpreter().GetScriptInterpreter();
88   if (m_interpreter) {
89 
90     std::string os_plugin_class_name(
91         python_module_path.GetFilename().AsCString(""));
92     if (!os_plugin_class_name.empty()) {
93       const bool init_session = false;
94       const bool allow_reload = true;
95       char python_module_path_cstr[PATH_MAX];
96       python_module_path.GetPath(python_module_path_cstr,
97                                  sizeof(python_module_path_cstr));
98       Error error;
99       if (m_interpreter->LoadScriptingModule(
100               python_module_path_cstr, allow_reload, init_session, error)) {
101         // Strip the ".py" extension if there is one
102         size_t py_extension_pos = os_plugin_class_name.rfind(".py");
103         if (py_extension_pos != std::string::npos)
104           os_plugin_class_name.erase(py_extension_pos);
105         // Add ".OperatingSystemPlugIn" to the module name to get a string like
106         // "modulename.OperatingSystemPlugIn"
107         os_plugin_class_name += ".OperatingSystemPlugIn";
108         StructuredData::ObjectSP object_sp =
109             m_interpreter->OSPlugin_CreatePluginObject(
110                 os_plugin_class_name.c_str(), process->CalculateProcess());
111         if (object_sp && object_sp->IsValid())
112           m_python_object_sp = object_sp;
113       }
114     }
115   }
116 }
117 
118 OperatingSystemPython::~OperatingSystemPython() {}
119 
120 DynamicRegisterInfo *OperatingSystemPython::GetDynamicRegisterInfo() {
121   if (m_register_info_ap.get() == NULL) {
122     if (!m_interpreter || !m_python_object_sp)
123       return NULL;
124     Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_OS));
125 
126     if (log)
127       log->Printf("OperatingSystemPython::GetDynamicRegisterInfo() fetching "
128                   "thread register definitions from python for pid %" PRIu64,
129                   m_process->GetID());
130 
131     StructuredData::DictionarySP dictionary =
132         m_interpreter->OSPlugin_RegisterInfo(m_python_object_sp);
133     if (!dictionary)
134       return NULL;
135 
136     m_register_info_ap.reset(new DynamicRegisterInfo(
137         *dictionary, m_process->GetTarget().GetArchitecture()));
138     assert(m_register_info_ap->GetNumRegisters() > 0);
139     assert(m_register_info_ap->GetNumRegisterSets() > 0);
140   }
141   return m_register_info_ap.get();
142 }
143 
144 //------------------------------------------------------------------
145 // PluginInterface protocol
146 //------------------------------------------------------------------
147 ConstString OperatingSystemPython::GetPluginName() {
148   return GetPluginNameStatic();
149 }
150 
151 uint32_t OperatingSystemPython::GetPluginVersion() { return 1; }
152 
153 bool OperatingSystemPython::UpdateThreadList(ThreadList &old_thread_list,
154                                              ThreadList &core_thread_list,
155                                              ThreadList &new_thread_list) {
156   if (!m_interpreter || !m_python_object_sp)
157     return false;
158 
159   Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_OS));
160 
161   // First thing we have to do is to try to get the API lock, and the run lock.
162   // We're going to change the thread content of the process, and we're going
163   // to use python, which requires the API lock to do it.
164   //
165   // If someone already has the API lock, that is ok, we just want to avoid
166   // external code from making new API calls while this call is happening.
167   //
168   // This is a recursive lock so we can grant it to any Python code called on
169   // the stack below us.
170   Target &target = m_process->GetTarget();
171   std::unique_lock<std::recursive_mutex> lock(target.GetAPIMutex(),
172                                               std::defer_lock);
173   lock.try_lock();
174 
175   if (log)
176     log->Printf("OperatingSystemPython::UpdateThreadList() fetching thread "
177                 "data from python for pid %" PRIu64,
178                 m_process->GetID());
179 
180   // The threads that are in "new_thread_list" upon entry are the threads from
181   // the
182   // lldb_private::Process subclass, no memory threads will be in this list.
183 
184   auto interpreter_lock =
185       m_interpreter
186           ->AcquireInterpreterLock(); // to make sure threads_list stays alive
187   StructuredData::ArraySP threads_list =
188       m_interpreter->OSPlugin_ThreadsInfo(m_python_object_sp);
189 
190   const uint32_t num_cores = core_thread_list.GetSize(false);
191 
192   // Make a map so we can keep track of which cores were used from the
193   // core_thread list. Any real threads/cores that weren't used should
194   // later be put back into the "new_thread_list".
195   std::vector<bool> core_used_map(num_cores, false);
196   if (threads_list) {
197     if (log) {
198       StreamString strm;
199       threads_list->Dump(strm);
200       log->Printf("threads_list = %s", strm.GetString().c_str());
201     }
202 
203     const uint32_t num_threads = threads_list->GetSize();
204     for (uint32_t i = 0; i < num_threads; ++i) {
205       StructuredData::ObjectSP thread_dict_obj =
206           threads_list->GetItemAtIndex(i);
207       if (auto thread_dict = thread_dict_obj->GetAsDictionary()) {
208         ThreadSP thread_sp(
209             CreateThreadFromThreadInfo(*thread_dict, core_thread_list,
210                                        old_thread_list, core_used_map, NULL));
211         if (thread_sp)
212           new_thread_list.AddThread(thread_sp);
213       }
214     }
215   }
216 
217   // Any real core threads that didn't end up backing a memory thread should
218   // still be in the main thread list, and they should be inserted at the
219   // beginning
220   // of the list
221   uint32_t insert_idx = 0;
222   for (uint32_t core_idx = 0; core_idx < num_cores; ++core_idx) {
223     if (core_used_map[core_idx] == false) {
224       new_thread_list.InsertThread(
225           core_thread_list.GetThreadAtIndex(core_idx, false), insert_idx);
226       ++insert_idx;
227     }
228   }
229 
230   return new_thread_list.GetSize(false) > 0;
231 }
232 
233 ThreadSP OperatingSystemPython::CreateThreadFromThreadInfo(
234     StructuredData::Dictionary &thread_dict, ThreadList &core_thread_list,
235     ThreadList &old_thread_list, std::vector<bool> &core_used_map,
236     bool *did_create_ptr) {
237   ThreadSP thread_sp;
238   tid_t tid = LLDB_INVALID_THREAD_ID;
239   if (!thread_dict.GetValueForKeyAsInteger("tid", tid))
240     return ThreadSP();
241 
242   uint32_t core_number;
243   addr_t reg_data_addr;
244   std::string name;
245   std::string queue;
246 
247   thread_dict.GetValueForKeyAsInteger("core", core_number, UINT32_MAX);
248   thread_dict.GetValueForKeyAsInteger("register_data_addr", reg_data_addr,
249                                       LLDB_INVALID_ADDRESS);
250   thread_dict.GetValueForKeyAsString("name", name);
251   thread_dict.GetValueForKeyAsString("queue", queue);
252 
253   // See if a thread already exists for "tid"
254   thread_sp = old_thread_list.FindThreadByID(tid, false);
255   if (thread_sp) {
256     // A thread already does exist for "tid", make sure it was an operating
257     // system
258     // plug-in generated thread.
259     if (!IsOperatingSystemPluginThread(thread_sp)) {
260       // We have thread ID overlap between the protocol threads and the
261       // operating system threads, clear the thread so we create an
262       // operating system thread for this.
263       thread_sp.reset();
264     }
265   }
266 
267   if (!thread_sp) {
268     if (did_create_ptr)
269       *did_create_ptr = true;
270     thread_sp.reset(new ThreadMemory(*m_process, tid, name.c_str(),
271                                      queue.c_str(), reg_data_addr));
272   }
273 
274   if (core_number < core_thread_list.GetSize(false)) {
275     ThreadSP core_thread_sp(
276         core_thread_list.GetThreadAtIndex(core_number, false));
277     if (core_thread_sp) {
278       // Keep track of which cores were set as the backing thread for memory
279       // threads...
280       if (core_number < core_used_map.size())
281         core_used_map[core_number] = true;
282 
283       ThreadSP backing_core_thread_sp(core_thread_sp->GetBackingThread());
284       if (backing_core_thread_sp) {
285         thread_sp->SetBackingThread(backing_core_thread_sp);
286       } else {
287         thread_sp->SetBackingThread(core_thread_sp);
288       }
289     }
290   }
291   return thread_sp;
292 }
293 
294 void OperatingSystemPython::ThreadWasSelected(Thread *thread) {}
295 
296 RegisterContextSP
297 OperatingSystemPython::CreateRegisterContextForThread(Thread *thread,
298                                                       addr_t reg_data_addr) {
299   RegisterContextSP reg_ctx_sp;
300   if (!m_interpreter || !m_python_object_sp || !thread)
301     return reg_ctx_sp;
302 
303   if (!IsOperatingSystemPluginThread(thread->shared_from_this()))
304     return reg_ctx_sp;
305 
306   // First thing we have to do is get the API lock, and the run lock.  We're
307   // going to change the thread
308   // content of the process, and we're going to use python, which requires the
309   // API lock to do it.
310   // So get & hold that.  This is a recursive lock so we can grant it to any
311   // Python code called on the stack below us.
312   Target &target = m_process->GetTarget();
313   std::lock_guard<std::recursive_mutex> guard(target.GetAPIMutex());
314 
315   Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_THREAD));
316 
317   auto lock =
318       m_interpreter
319           ->AcquireInterpreterLock(); // to make sure python objects stays alive
320   if (reg_data_addr != LLDB_INVALID_ADDRESS) {
321     // The registers data is in contiguous memory, just create the register
322     // context using the address provided
323     if (log)
324       log->Printf("OperatingSystemPython::CreateRegisterContextForThread (tid "
325                   "= 0x%" PRIx64 ", 0x%" PRIx64 ", reg_data_addr = 0x%" PRIx64
326                   ") creating memory register context",
327                   thread->GetID(), thread->GetProtocolID(), reg_data_addr);
328     reg_ctx_sp.reset(new RegisterContextMemory(
329         *thread, 0, *GetDynamicRegisterInfo(), reg_data_addr));
330   } else {
331     // No register data address is provided, query the python plug-in to let
332     // it make up the data as it sees fit
333     if (log)
334       log->Printf("OperatingSystemPython::CreateRegisterContextForThread (tid "
335                   "= 0x%" PRIx64 ", 0x%" PRIx64
336                   ") fetching register data from python",
337                   thread->GetID(), thread->GetProtocolID());
338 
339     StructuredData::StringSP reg_context_data =
340         m_interpreter->OSPlugin_RegisterContextData(m_python_object_sp,
341                                                     thread->GetID());
342     if (reg_context_data) {
343       std::string value = reg_context_data->GetValue();
344       DataBufferSP data_sp(new DataBufferHeap(value.c_str(), value.length()));
345       if (data_sp->GetByteSize()) {
346         RegisterContextMemory *reg_ctx_memory = new RegisterContextMemory(
347             *thread, 0, *GetDynamicRegisterInfo(), LLDB_INVALID_ADDRESS);
348         if (reg_ctx_memory) {
349           reg_ctx_sp.reset(reg_ctx_memory);
350           reg_ctx_memory->SetAllRegisterData(data_sp);
351         }
352       }
353     }
354   }
355   // if we still have no register data, fallback on a dummy context to avoid
356   // crashing
357   if (!reg_ctx_sp) {
358     if (log)
359       log->Printf("OperatingSystemPython::CreateRegisterContextForThread (tid "
360                   "= 0x%" PRIx64 ") forcing a dummy register context",
361                   thread->GetID());
362     reg_ctx_sp.reset(new RegisterContextDummy(
363         *thread, 0, target.GetArchitecture().GetAddressByteSize()));
364   }
365   return reg_ctx_sp;
366 }
367 
368 StopInfoSP
369 OperatingSystemPython::CreateThreadStopReason(lldb_private::Thread *thread) {
370   // We should have gotten the thread stop info from the dictionary of data for
371   // the thread in the initial call to get_thread_info(), this should have been
372   // cached so we can return it here
373   StopInfoSP
374       stop_info_sp; //(StopInfo::CreateStopReasonWithSignal (*thread, SIGSTOP));
375   return stop_info_sp;
376 }
377 
378 lldb::ThreadSP OperatingSystemPython::CreateThread(lldb::tid_t tid,
379                                                    addr_t context) {
380   Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_THREAD));
381 
382   if (log)
383     log->Printf("OperatingSystemPython::CreateThread (tid = 0x%" PRIx64
384                 ", context = 0x%" PRIx64 ") fetching register data from python",
385                 tid, context);
386 
387   if (m_interpreter && m_python_object_sp) {
388     // First thing we have to do is get the API lock, and the run lock.  We're
389     // going to change the thread
390     // content of the process, and we're going to use python, which requires the
391     // API lock to do it.
392     // So get & hold that.  This is a recursive lock so we can grant it to any
393     // Python code called on the stack below us.
394     Target &target = m_process->GetTarget();
395     std::lock_guard<std::recursive_mutex> guard(target.GetAPIMutex());
396 
397     auto lock = m_interpreter->AcquireInterpreterLock(); // to make sure
398                                                          // thread_info_dict
399                                                          // stays alive
400     StructuredData::DictionarySP thread_info_dict =
401         m_interpreter->OSPlugin_CreateThread(m_python_object_sp, tid, context);
402     std::vector<bool> core_used_map;
403     if (thread_info_dict) {
404       ThreadList core_threads(m_process);
405       ThreadList &thread_list = m_process->GetThreadList();
406       bool did_create = false;
407       ThreadSP thread_sp(
408           CreateThreadFromThreadInfo(*thread_info_dict, core_threads,
409                                      thread_list, core_used_map, &did_create));
410       if (did_create)
411         thread_list.AddThread(thread_sp);
412       return thread_sp;
413     }
414   }
415   return ThreadSP();
416 }
417 
418 #endif // #ifndef LLDB_DISABLE_PYTHON
419