xref: /llvm-project/lldb/source/Plugins/OperatingSystem/Python/OperatingSystemPython.cpp (revision ceff6644bba4d6c5e9c338afe92c453c7597609b)
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 #include "Plugins/Process/Utility/DynamicRegisterInfo.h"
14 #include "Plugins/Process/Utility/RegisterContextDummy.h"
15 #include "Plugins/Process/Utility/RegisterContextMemory.h"
16 #include "Plugins/Process/Utility/ThreadMemory.h"
17 #include "lldb/Core/Debugger.h"
18 #include "lldb/Core/Module.h"
19 #include "lldb/Core/PluginManager.h"
20 #include "lldb/Core/ValueObjectVariable.h"
21 #include "lldb/Interpreter/CommandInterpreter.h"
22 #include "lldb/Interpreter/ScriptInterpreter.h"
23 #include "lldb/Symbol/ObjectFile.h"
24 #include "lldb/Symbol/VariableList.h"
25 #include "lldb/Target/Process.h"
26 #include "lldb/Target/StopInfo.h"
27 #include "lldb/Target/Target.h"
28 #include "lldb/Target/Thread.h"
29 #include "lldb/Target/ThreadList.h"
30 #include "lldb/Utility/DataBufferHeap.h"
31 #include "lldb/Utility/RegisterValue.h"
32 #include "lldb/Utility/StreamString.h"
33 #include "lldb/Utility/StructuredData.h"
34 
35 using namespace lldb;
36 using namespace lldb_private;
37 
38 void OperatingSystemPython::Initialize() {
39   PluginManager::RegisterPlugin(GetPluginNameStatic(),
40                                 GetPluginDescriptionStatic(), CreateInstance,
41                                 nullptr);
42 }
43 
44 void OperatingSystemPython::Terminate() {
45   PluginManager::UnregisterPlugin(CreateInstance);
46 }
47 
48 OperatingSystem *OperatingSystemPython::CreateInstance(Process *process,
49                                                        bool force) {
50   // Python OperatingSystem plug-ins must be requested by name, so force must
51   // be true
52   FileSpec python_os_plugin_spec(process->GetPythonOSPluginPath());
53   if (python_os_plugin_spec &&
54       FileSystem::Instance().Exists(python_os_plugin_spec)) {
55     std::unique_ptr<OperatingSystemPython> os_ap(
56         new OperatingSystemPython(process, python_os_plugin_spec));
57     if (os_ap.get() && os_ap->IsValid())
58       return os_ap.release();
59   }
60   return NULL;
61 }
62 
63 ConstString OperatingSystemPython::GetPluginNameStatic() {
64   static ConstString g_name("python");
65   return g_name;
66 }
67 
68 const char *OperatingSystemPython::GetPluginDescriptionStatic() {
69   return "Operating system plug-in that gathers OS information from a python "
70          "class that implements the necessary OperatingSystem functionality.";
71 }
72 
73 OperatingSystemPython::OperatingSystemPython(lldb_private::Process *process,
74                                              const FileSpec &python_module_path)
75     : OperatingSystem(process), m_thread_list_valobj_sp(), m_register_info_ap(),
76       m_interpreter(NULL), m_python_object_sp() {
77   if (!process)
78     return;
79   TargetSP target_sp = process->CalculateTarget();
80   if (!target_sp)
81     return;
82   m_interpreter =
83       target_sp->GetDebugger().GetCommandInterpreter().GetScriptInterpreter();
84   if (m_interpreter) {
85 
86     std::string os_plugin_class_name(
87         python_module_path.GetFilename().AsCString(""));
88     if (!os_plugin_class_name.empty()) {
89       const bool init_session = false;
90       const bool allow_reload = true;
91       char python_module_path_cstr[PATH_MAX];
92       python_module_path.GetPath(python_module_path_cstr,
93                                  sizeof(python_module_path_cstr));
94       Status error;
95       if (m_interpreter->LoadScriptingModule(
96               python_module_path_cstr, allow_reload, init_session, error)) {
97         // Strip the ".py" extension if there is one
98         size_t py_extension_pos = os_plugin_class_name.rfind(".py");
99         if (py_extension_pos != std::string::npos)
100           os_plugin_class_name.erase(py_extension_pos);
101         // Add ".OperatingSystemPlugIn" to the module name to get a string like
102         // "modulename.OperatingSystemPlugIn"
103         os_plugin_class_name += ".OperatingSystemPlugIn";
104         StructuredData::ObjectSP object_sp =
105             m_interpreter->OSPlugin_CreatePluginObject(
106                 os_plugin_class_name.c_str(), process->CalculateProcess());
107         if (object_sp && object_sp->IsValid())
108           m_python_object_sp = object_sp;
109       }
110     }
111   }
112 }
113 
114 OperatingSystemPython::~OperatingSystemPython() {}
115 
116 DynamicRegisterInfo *OperatingSystemPython::GetDynamicRegisterInfo() {
117   if (m_register_info_ap.get() == NULL) {
118     if (!m_interpreter || !m_python_object_sp)
119       return NULL;
120     Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_OS));
121 
122     if (log)
123       log->Printf("OperatingSystemPython::GetDynamicRegisterInfo() fetching "
124                   "thread register definitions from python for pid %" PRIu64,
125                   m_process->GetID());
126 
127     StructuredData::DictionarySP dictionary =
128         m_interpreter->OSPlugin_RegisterInfo(m_python_object_sp);
129     if (!dictionary)
130       return NULL;
131 
132     m_register_info_ap.reset(new DynamicRegisterInfo(
133         *dictionary, m_process->GetTarget().GetArchitecture()));
134     assert(m_register_info_ap->GetNumRegisters() > 0);
135     assert(m_register_info_ap->GetNumRegisterSets() > 0);
136   }
137   return m_register_info_ap.get();
138 }
139 
140 //------------------------------------------------------------------
141 // PluginInterface protocol
142 //------------------------------------------------------------------
143 ConstString OperatingSystemPython::GetPluginName() {
144   return GetPluginNameStatic();
145 }
146 
147 uint32_t OperatingSystemPython::GetPluginVersion() { return 1; }
148 
149 bool OperatingSystemPython::UpdateThreadList(ThreadList &old_thread_list,
150                                              ThreadList &core_thread_list,
151                                              ThreadList &new_thread_list) {
152   if (!m_interpreter || !m_python_object_sp)
153     return false;
154 
155   Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_OS));
156 
157   // First thing we have to do is to try to get the API lock, and the
158   // interpreter lock. We're going to change the thread content of the process,
159   // and we're going to use python, which requires the API lock to do it. We
160   // need the interpreter lock to make sure thread_info_dict stays alive.
161   //
162   // If someone already has the API lock, that is ok, we just want to avoid
163   // external code from making new API calls while this call is happening.
164   //
165   // This is a recursive lock so we can grant it to any Python code called on
166   // the stack below us.
167   Target &target = m_process->GetTarget();
168   std::unique_lock<std::recursive_mutex> api_lock(target.GetAPIMutex(),
169                                                   std::defer_lock);
170   api_lock.try_lock();
171   auto interpreter_lock = m_interpreter->AcquireInterpreterLock();
172 
173   if (log)
174     log->Printf("OperatingSystemPython::UpdateThreadList() fetching thread "
175                 "data from python for pid %" PRIu64,
176                 m_process->GetID());
177 
178   // The threads that are in "new_thread_list" upon entry are the threads from
179   // the lldb_private::Process subclass, no memory threads will be in this
180   // list.
181   StructuredData::ArraySP threads_list =
182       m_interpreter->OSPlugin_ThreadsInfo(m_python_object_sp);
183 
184   const uint32_t num_cores = core_thread_list.GetSize(false);
185 
186   // Make a map so we can keep track of which cores were used from the
187   // core_thread list. Any real threads/cores that weren't used should later be
188   // put back into the "new_thread_list".
189   std::vector<bool> core_used_map(num_cores, false);
190   if (threads_list) {
191     if (log) {
192       StreamString strm;
193       threads_list->Dump(strm);
194       log->Printf("threads_list = %s", strm.GetData());
195     }
196 
197     const uint32_t num_threads = threads_list->GetSize();
198     for (uint32_t i = 0; i < num_threads; ++i) {
199       StructuredData::ObjectSP thread_dict_obj =
200           threads_list->GetItemAtIndex(i);
201       if (auto thread_dict = thread_dict_obj->GetAsDictionary()) {
202         ThreadSP thread_sp(
203             CreateThreadFromThreadInfo(*thread_dict, core_thread_list,
204                                        old_thread_list, core_used_map, NULL));
205         if (thread_sp)
206           new_thread_list.AddThread(thread_sp);
207       }
208     }
209   }
210 
211   // Any real core threads that didn't end up backing a memory thread should
212   // still be in the main thread list, and they should be inserted at the
213   // beginning of the list
214   uint32_t insert_idx = 0;
215   for (uint32_t core_idx = 0; core_idx < num_cores; ++core_idx) {
216     if (core_used_map[core_idx] == false) {
217       new_thread_list.InsertThread(
218           core_thread_list.GetThreadAtIndex(core_idx, false), insert_idx);
219       ++insert_idx;
220     }
221   }
222 
223   return new_thread_list.GetSize(false) > 0;
224 }
225 
226 ThreadSP OperatingSystemPython::CreateThreadFromThreadInfo(
227     StructuredData::Dictionary &thread_dict, ThreadList &core_thread_list,
228     ThreadList &old_thread_list, std::vector<bool> &core_used_map,
229     bool *did_create_ptr) {
230   ThreadSP thread_sp;
231   tid_t tid = LLDB_INVALID_THREAD_ID;
232   if (!thread_dict.GetValueForKeyAsInteger("tid", tid))
233     return ThreadSP();
234 
235   uint32_t core_number;
236   addr_t reg_data_addr;
237   llvm::StringRef name;
238   llvm::StringRef queue;
239 
240   thread_dict.GetValueForKeyAsInteger("core", core_number, UINT32_MAX);
241   thread_dict.GetValueForKeyAsInteger("register_data_addr", reg_data_addr,
242                                       LLDB_INVALID_ADDRESS);
243   thread_dict.GetValueForKeyAsString("name", name);
244   thread_dict.GetValueForKeyAsString("queue", queue);
245 
246   // See if a thread already exists for "tid"
247   thread_sp = old_thread_list.FindThreadByID(tid, false);
248   if (thread_sp) {
249     // A thread already does exist for "tid", make sure it was an operating
250     // system
251     // plug-in generated thread.
252     if (!IsOperatingSystemPluginThread(thread_sp)) {
253       // We have thread ID overlap between the protocol threads and the
254       // operating system threads, clear the thread so we create an operating
255       // system thread for this.
256       thread_sp.reset();
257     }
258   }
259 
260   if (!thread_sp) {
261     if (did_create_ptr)
262       *did_create_ptr = true;
263     thread_sp.reset(
264         new ThreadMemory(*m_process, tid, name, queue, reg_data_addr));
265   }
266 
267   if (core_number < core_thread_list.GetSize(false)) {
268     ThreadSP core_thread_sp(
269         core_thread_list.GetThreadAtIndex(core_number, false));
270     if (core_thread_sp) {
271       // Keep track of which cores were set as the backing thread for memory
272       // threads...
273       if (core_number < core_used_map.size())
274         core_used_map[core_number] = true;
275 
276       ThreadSP backing_core_thread_sp(core_thread_sp->GetBackingThread());
277       if (backing_core_thread_sp) {
278         thread_sp->SetBackingThread(backing_core_thread_sp);
279       } else {
280         thread_sp->SetBackingThread(core_thread_sp);
281       }
282     }
283   }
284   return thread_sp;
285 }
286 
287 void OperatingSystemPython::ThreadWasSelected(Thread *thread) {}
288 
289 RegisterContextSP
290 OperatingSystemPython::CreateRegisterContextForThread(Thread *thread,
291                                                       addr_t reg_data_addr) {
292   RegisterContextSP reg_ctx_sp;
293   if (!m_interpreter || !m_python_object_sp || !thread)
294     return reg_ctx_sp;
295 
296   if (!IsOperatingSystemPluginThread(thread->shared_from_this()))
297     return reg_ctx_sp;
298 
299   // First thing we have to do is to try to get the API lock, and the
300   // interpreter lock. We're going to change the thread content of the process,
301   // and we're going to use python, which requires the API lock to do it. We
302   // need the interpreter lock to make sure thread_info_dict stays alive.
303   //
304   // If someone already has the API lock, that is ok, we just want to avoid
305   // external code from making new API calls while this call is happening.
306   //
307   // This is a recursive lock so we can grant it to any Python code called on
308   // the stack below us.
309   Target &target = m_process->GetTarget();
310   std::unique_lock<std::recursive_mutex> api_lock(target.GetAPIMutex(),
311                                                   std::defer_lock);
312   api_lock.try_lock();
313   auto interpreter_lock = m_interpreter->AcquireInterpreterLock();
314 
315   Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_THREAD));
316 
317   if (reg_data_addr != LLDB_INVALID_ADDRESS) {
318     // The registers data is in contiguous memory, just create the register
319     // context using the address provided
320     if (log)
321       log->Printf("OperatingSystemPython::CreateRegisterContextForThread (tid "
322                   "= 0x%" PRIx64 ", 0x%" PRIx64 ", reg_data_addr = 0x%" PRIx64
323                   ") creating memory register context",
324                   thread->GetID(), thread->GetProtocolID(), reg_data_addr);
325     reg_ctx_sp.reset(new RegisterContextMemory(
326         *thread, 0, *GetDynamicRegisterInfo(), reg_data_addr));
327   } else {
328     // No register data address is provided, query the python plug-in to let it
329     // make up the data as it sees fit
330     if (log)
331       log->Printf("OperatingSystemPython::CreateRegisterContextForThread (tid "
332                   "= 0x%" PRIx64 ", 0x%" PRIx64
333                   ") fetching register data from python",
334                   thread->GetID(), thread->GetProtocolID());
335 
336     StructuredData::StringSP reg_context_data =
337         m_interpreter->OSPlugin_RegisterContextData(m_python_object_sp,
338                                                     thread->GetID());
339     if (reg_context_data) {
340       std::string value = reg_context_data->GetValue();
341       DataBufferSP data_sp(new DataBufferHeap(value.c_str(), value.length()));
342       if (data_sp->GetByteSize()) {
343         RegisterContextMemory *reg_ctx_memory = new RegisterContextMemory(
344             *thread, 0, *GetDynamicRegisterInfo(), LLDB_INVALID_ADDRESS);
345         if (reg_ctx_memory) {
346           reg_ctx_sp.reset(reg_ctx_memory);
347           reg_ctx_memory->SetAllRegisterData(data_sp);
348         }
349       }
350     }
351   }
352   // if we still have no register data, fallback on a dummy context to avoid
353   // crashing
354   if (!reg_ctx_sp) {
355     if (log)
356       log->Printf("OperatingSystemPython::CreateRegisterContextForThread (tid "
357                   "= 0x%" PRIx64 ") forcing a dummy register context",
358                   thread->GetID());
359     reg_ctx_sp.reset(new RegisterContextDummy(
360         *thread, 0, target.GetArchitecture().GetAddressByteSize()));
361   }
362   return reg_ctx_sp;
363 }
364 
365 StopInfoSP
366 OperatingSystemPython::CreateThreadStopReason(lldb_private::Thread *thread) {
367   // We should have gotten the thread stop info from the dictionary of data for
368   // the thread in the initial call to get_thread_info(), this should have been
369   // cached so we can return it here
370   StopInfoSP
371       stop_info_sp; //(StopInfo::CreateStopReasonWithSignal (*thread, SIGSTOP));
372   return stop_info_sp;
373 }
374 
375 lldb::ThreadSP OperatingSystemPython::CreateThread(lldb::tid_t tid,
376                                                    addr_t context) {
377   Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_THREAD));
378 
379   if (log)
380     log->Printf("OperatingSystemPython::CreateThread (tid = 0x%" PRIx64
381                 ", context = 0x%" PRIx64 ") fetching register data from python",
382                 tid, context);
383 
384   if (m_interpreter && m_python_object_sp) {
385     // First thing we have to do is to try to get the API lock, and the
386     // interpreter lock. We're going to change the thread content of the
387     // process, and we're going to use python, which requires the API lock to
388     // do it. We need the interpreter lock to make sure thread_info_dict stays
389     // alive.
390     //
391     // If someone already has the API lock, that is ok, we just want to avoid
392     // external code from making new API calls while this call is happening.
393     //
394     // This is a recursive lock so we can grant it to any Python code called on
395     // the stack below us.
396     Target &target = m_process->GetTarget();
397     std::unique_lock<std::recursive_mutex> api_lock(target.GetAPIMutex(),
398                                                     std::defer_lock);
399     api_lock.try_lock();
400     auto interpreter_lock = m_interpreter->AcquireInterpreterLock();
401 
402     StructuredData::DictionarySP thread_info_dict =
403         m_interpreter->OSPlugin_CreateThread(m_python_object_sp, tid, context);
404     std::vector<bool> core_used_map;
405     if (thread_info_dict) {
406       ThreadList core_threads(m_process);
407       ThreadList &thread_list = m_process->GetThreadList();
408       bool did_create = false;
409       ThreadSP thread_sp(
410           CreateThreadFromThreadInfo(*thread_info_dict, core_threads,
411                                      thread_list, core_used_map, &did_create));
412       if (did_create)
413         thread_list.AddThread(thread_sp);
414       return thread_sp;
415     }
416   }
417   return ThreadSP();
418 }
419 
420 #endif // #ifndef LLDB_DISABLE_PYTHON
421