xref: /llvm-project/lldb/source/Plugins/OperatingSystem/Python/OperatingSystemPython.cpp (revision 1124045ac739480b69eb7c9be2ce09d4898c4ed0)
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 "lldb/Core/ArchSpec.h"
17 #include "lldb/Core/DataBufferHeap.h"
18 #include "lldb/Core/Debugger.h"
19 #include "lldb/Core/Module.h"
20 #include "lldb/Core/PluginManager.h"
21 #include "lldb/Core/RegisterValue.h"
22 #include "lldb/Core/StreamString.h"
23 #include "lldb/Core/StructuredData.h"
24 #include "lldb/Core/ValueObjectVariable.h"
25 #include "lldb/Interpreter/CommandInterpreter.h"
26 #include "lldb/Interpreter/ScriptInterpreter.h"
27 #include "lldb/Symbol/ClangNamespaceDecl.h"
28 #include "lldb/Symbol/ObjectFile.h"
29 #include "lldb/Symbol/VariableList.h"
30 #include "lldb/Target/Process.h"
31 #include "lldb/Target/StopInfo.h"
32 #include "lldb/Target/Target.h"
33 #include "lldb/Target/ThreadList.h"
34 #include "lldb/Target/Thread.h"
35 #include "Plugins/Process/Utility/DynamicRegisterInfo.h"
36 #include "Plugins/Process/Utility/RegisterContextDummy.h"
37 #include "Plugins/Process/Utility/RegisterContextMemory.h"
38 #include "Plugins/Process/Utility/ThreadMemory.h"
39 
40 using namespace lldb;
41 using namespace lldb_private;
42 
43 void
44 OperatingSystemPython::Initialize()
45 {
46     PluginManager::RegisterPlugin (GetPluginNameStatic(),
47                                    GetPluginDescriptionStatic(),
48                                    CreateInstance);
49 }
50 
51 void
52 OperatingSystemPython::Terminate()
53 {
54     PluginManager::UnregisterPlugin (CreateInstance);
55 }
56 
57 OperatingSystem *
58 OperatingSystemPython::CreateInstance (Process *process, bool force)
59 {
60     // Python OperatingSystem plug-ins must be requested by name, so force must be true
61     FileSpec python_os_plugin_spec (process->GetPythonOSPluginPath());
62     if (python_os_plugin_spec && python_os_plugin_spec.Exists())
63     {
64         std::unique_ptr<OperatingSystemPython> os_ap (new OperatingSystemPython (process, python_os_plugin_spec));
65         if (os_ap.get() && os_ap->IsValid())
66             return os_ap.release();
67     }
68     return NULL;
69 }
70 
71 
72 ConstString
73 OperatingSystemPython::GetPluginNameStatic()
74 {
75     static ConstString g_name("python");
76     return g_name;
77 }
78 
79 const char *
80 OperatingSystemPython::GetPluginDescriptionStatic()
81 {
82     return "Operating system plug-in that gathers OS information from a python class that implements the necessary OperatingSystem functionality.";
83 }
84 
85 
86 OperatingSystemPython::OperatingSystemPython (lldb_private::Process *process, const FileSpec &python_module_path) :
87     OperatingSystem (process),
88     m_thread_list_valobj_sp (),
89     m_register_info_ap (),
90     m_interpreter (NULL),
91     m_python_object_sp ()
92 {
93     if (!process)
94         return;
95     TargetSP target_sp = process->CalculateTarget();
96     if (!target_sp)
97         return;
98     m_interpreter = target_sp->GetDebugger().GetCommandInterpreter().GetScriptInterpreter();
99     if (m_interpreter)
100     {
101 
102         std::string os_plugin_class_name (python_module_path.GetFilename().AsCString(""));
103         if (!os_plugin_class_name.empty())
104         {
105             const bool init_session = false;
106             const bool allow_reload = true;
107             char python_module_path_cstr[PATH_MAX];
108             python_module_path.GetPath(python_module_path_cstr, sizeof(python_module_path_cstr));
109             Error error;
110             if (m_interpreter->LoadScriptingModule (python_module_path_cstr, allow_reload, init_session, error))
111             {
112                 // Strip the ".py" extension if there is one
113                 size_t py_extension_pos = os_plugin_class_name.rfind(".py");
114                 if (py_extension_pos != std::string::npos)
115                     os_plugin_class_name.erase (py_extension_pos);
116                 // Add ".OperatingSystemPlugIn" to the module name to get a string like "modulename.OperatingSystemPlugIn"
117                 os_plugin_class_name += ".OperatingSystemPlugIn";
118                 StructuredData::ObjectSP object_sp =
119                     m_interpreter->OSPlugin_CreatePluginObject(os_plugin_class_name.c_str(), process->CalculateProcess());
120                 if (object_sp && object_sp->IsValid())
121                     m_python_object_sp = object_sp;
122             }
123         }
124     }
125 }
126 
127 OperatingSystemPython::~OperatingSystemPython ()
128 {
129 }
130 
131 DynamicRegisterInfo *
132 OperatingSystemPython::GetDynamicRegisterInfo ()
133 {
134     if (m_register_info_ap.get() == NULL)
135     {
136         if (!m_interpreter || !m_python_object_sp)
137             return NULL;
138         Log *log(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_OS));
139 
140         if (log)
141             log->Printf ("OperatingSystemPython::GetDynamicRegisterInfo() fetching thread register definitions from python for pid %" PRIu64, m_process->GetID());
142 
143         StructuredData::DictionarySP dictionary = m_interpreter->OSPlugin_RegisterInfo(m_python_object_sp);
144         if (!dictionary)
145             return NULL;
146 
147         m_register_info_ap.reset(new DynamicRegisterInfo(*dictionary, m_process->GetTarget().GetArchitecture()));
148         assert (m_register_info_ap->GetNumRegisters() > 0);
149         assert (m_register_info_ap->GetNumRegisterSets() > 0);
150     }
151     return m_register_info_ap.get();
152 }
153 
154 //------------------------------------------------------------------
155 // PluginInterface protocol
156 //------------------------------------------------------------------
157 ConstString
158 OperatingSystemPython::GetPluginName()
159 {
160     return GetPluginNameStatic();
161 }
162 
163 uint32_t
164 OperatingSystemPython::GetPluginVersion()
165 {
166     return 1;
167 }
168 
169 bool
170 OperatingSystemPython::UpdateThreadList (ThreadList &old_thread_list,
171                                          ThreadList &core_thread_list,
172                                          ThreadList &new_thread_list)
173 {
174     if (!m_interpreter || !m_python_object_sp)
175         return false;
176 
177     Log *log(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_OS));
178 
179     // First thing we have to do is to try to get the API lock, and the run lock.
180     // We're going to change the thread content of the process, and we're going
181     // to use python, which requires the API lock to do it.
182     //
183     // If someone already has the API lock, that is ok, we just want to avoid
184     // external code from making new API calls while this call is happening.
185     //
186     // This is a recursive lock so we can grant it to any Python code called on
187     // the stack below us.
188     Target &target = m_process->GetTarget();
189     Mutex::Locker api_locker;
190     api_locker.TryLock(target.GetAPIMutex());
191 
192     if (log)
193         log->Printf ("OperatingSystemPython::UpdateThreadList() fetching thread data from python for pid %" PRIu64, m_process->GetID());
194 
195     // The threads that are in "new_thread_list" upon entry are the threads from the
196     // lldb_private::Process subclass, no memory threads will be in this list.
197 
198     auto lock = m_interpreter->AcquireInterpreterLock(); // to make sure threads_list stays alive
199     StructuredData::ArraySP threads_list = m_interpreter->OSPlugin_ThreadsInfo(m_python_object_sp);
200 
201     const uint32_t num_cores = core_thread_list.GetSize(false);
202 
203     // Make a map so we can keep track of which cores were used from the
204     // core_thread list. Any real threads/cores that weren't used should
205     // later be put back into the "new_thread_list".
206     std::vector<bool> core_used_map(num_cores, false);
207     if (threads_list)
208     {
209         if (log)
210         {
211             StreamString strm;
212             threads_list->Dump(strm);
213             log->Printf("threads_list = %s", strm.GetString().c_str());
214         }
215 
216         const uint32_t num_threads = threads_list->GetSize();
217         for (uint32_t i = 0; i < num_threads; ++i)
218         {
219             StructuredData::ObjectSP thread_dict_obj = threads_list->GetItemAtIndex(i);
220             if (auto thread_dict = thread_dict_obj->GetAsDictionary())
221             {
222                 ThreadSP thread_sp(CreateThreadFromThreadInfo(*thread_dict, core_thread_list, old_thread_list, core_used_map, NULL));
223                 if (thread_sp)
224                     new_thread_list.AddThread(thread_sp);
225             }
226         }
227     }
228 
229     // Any real core threads that didn't end up backing a memory thread should
230     // still be in the main thread list, and they should be inserted at the beginning
231     // of the list
232     uint32_t insert_idx = 0;
233     for (uint32_t core_idx = 0; core_idx < num_cores; ++core_idx)
234     {
235         if (core_used_map[core_idx] == false)
236         {
237             new_thread_list.InsertThread (core_thread_list.GetThreadAtIndex(core_idx, false), insert_idx);
238             ++insert_idx;
239         }
240     }
241 
242     return new_thread_list.GetSize(false) > 0;
243 }
244 
245 ThreadSP
246 OperatingSystemPython::CreateThreadFromThreadInfo(StructuredData::Dictionary &thread_dict, ThreadList &core_thread_list,
247                                                   ThreadList &old_thread_list, std::vector<bool> &core_used_map, bool *did_create_ptr)
248 {
249     ThreadSP thread_sp;
250     tid_t tid = LLDB_INVALID_THREAD_ID;
251     if (!thread_dict.GetValueForKeyAsInteger("tid", tid))
252         return ThreadSP();
253 
254     uint32_t core_number;
255     addr_t reg_data_addr;
256     std::string name;
257     std::string queue;
258 
259     thread_dict.GetValueForKeyAsInteger("core", core_number, UINT32_MAX);
260     thread_dict.GetValueForKeyAsInteger("register_data_addr", reg_data_addr, LLDB_INVALID_ADDRESS);
261     thread_dict.GetValueForKeyAsString("name", name);
262     thread_dict.GetValueForKeyAsString("queue", queue);
263 
264     // See if a thread already exists for "tid"
265     thread_sp = old_thread_list.FindThreadByID(tid, false);
266     if (thread_sp)
267     {
268         // A thread already does exist for "tid", make sure it was an operating system
269         // plug-in generated thread.
270         if (!IsOperatingSystemPluginThread(thread_sp))
271         {
272             // We have thread ID overlap between the protocol threads and the
273             // operating system threads, clear the thread so we create an
274             // operating system thread for this.
275             thread_sp.reset();
276         }
277     }
278 
279     if (!thread_sp)
280     {
281         if (did_create_ptr)
282             *did_create_ptr = true;
283         thread_sp.reset(new ThreadMemory(*m_process, tid, name.c_str(), queue.c_str(), reg_data_addr));
284     }
285 
286     if (core_number < core_thread_list.GetSize(false))
287     {
288         ThreadSP core_thread_sp(core_thread_list.GetThreadAtIndex(core_number, false));
289         if (core_thread_sp)
290         {
291             // Keep track of which cores were set as the backing thread for memory threads...
292             if (core_number < core_used_map.size())
293                 core_used_map[core_number] = true;
294 
295             ThreadSP backing_core_thread_sp(core_thread_sp->GetBackingThread());
296             if (backing_core_thread_sp)
297             {
298                 thread_sp->SetBackingThread(backing_core_thread_sp);
299             }
300             else
301             {
302                 thread_sp->SetBackingThread(core_thread_sp);
303             }
304         }
305     }
306     return thread_sp;
307 }
308 
309 
310 
311 void
312 OperatingSystemPython::ThreadWasSelected (Thread *thread)
313 {
314 }
315 
316 RegisterContextSP
317 OperatingSystemPython::CreateRegisterContextForThread (Thread *thread, addr_t reg_data_addr)
318 {
319     RegisterContextSP reg_ctx_sp;
320     if (!m_interpreter || !m_python_object_sp || !thread)
321         return reg_ctx_sp;
322 
323     if (!IsOperatingSystemPluginThread(thread->shared_from_this()))
324         return reg_ctx_sp;
325 
326     // First thing we have to do is get the API lock, and the run lock.  We're going to change the thread
327     // content of the process, and we're going to use python, which requires the API lock to do it.
328     // So get & hold that.  This is a recursive lock so we can grant it to any Python code called on the stack below us.
329     Target &target = m_process->GetTarget();
330     Mutex::Locker api_locker (target.GetAPIMutex());
331 
332     Log *log(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_THREAD));
333 
334     auto lock = m_interpreter->AcquireInterpreterLock(); // to make sure python objects stays alive
335     if (reg_data_addr != LLDB_INVALID_ADDRESS)
336     {
337         // The registers data is in contiguous memory, just create the register
338         // context using the address provided
339         if (log)
340             log->Printf ("OperatingSystemPython::CreateRegisterContextForThread (tid = 0x%" PRIx64 ", 0x%" PRIx64 ", reg_data_addr = 0x%" PRIx64 ") creating memory register context",
341                          thread->GetID(),
342                          thread->GetProtocolID(),
343                          reg_data_addr);
344         reg_ctx_sp.reset (new RegisterContextMemory (*thread, 0, *GetDynamicRegisterInfo (), reg_data_addr));
345     }
346     else
347     {
348         // No register data address is provided, query the python plug-in to let
349         // it make up the data as it sees fit
350         if (log)
351             log->Printf ("OperatingSystemPython::CreateRegisterContextForThread (tid = 0x%" PRIx64 ", 0x%" PRIx64 ") fetching register data from python",
352                          thread->GetID(),
353                          thread->GetProtocolID());
354 
355         StructuredData::StringSP reg_context_data = m_interpreter->OSPlugin_RegisterContextData(m_python_object_sp, thread->GetID());
356         if (reg_context_data)
357         {
358             std::string value = reg_context_data->GetValue();
359             DataBufferSP data_sp(new DataBufferHeap(value.c_str(), value.length()));
360             if (data_sp->GetByteSize())
361             {
362                 RegisterContextMemory *reg_ctx_memory = new RegisterContextMemory (*thread, 0, *GetDynamicRegisterInfo (), LLDB_INVALID_ADDRESS);
363                 if (reg_ctx_memory)
364                 {
365                     reg_ctx_sp.reset(reg_ctx_memory);
366                     reg_ctx_memory->SetAllRegisterData (data_sp);
367                 }
368             }
369         }
370     }
371     // if we still have no register data, fallback on a dummy context to avoid crashing
372     if (!reg_ctx_sp)
373     {
374         if (log)
375             log->Printf ("OperatingSystemPython::CreateRegisterContextForThread (tid = 0x%" PRIx64 ") forcing a dummy register context", thread->GetID());
376         reg_ctx_sp.reset(new RegisterContextDummy(*thread,0,target.GetArchitecture().GetAddressByteSize()));
377     }
378     return reg_ctx_sp;
379 }
380 
381 StopInfoSP
382 OperatingSystemPython::CreateThreadStopReason (lldb_private::Thread *thread)
383 {
384     // We should have gotten the thread stop info from the dictionary of data for
385     // the thread in the initial call to get_thread_info(), this should have been
386     // cached so we can return it here
387     StopInfoSP stop_info_sp; //(StopInfo::CreateStopReasonWithSignal (*thread, SIGSTOP));
388     return stop_info_sp;
389 }
390 
391 lldb::ThreadSP
392 OperatingSystemPython::CreateThread (lldb::tid_t tid, addr_t context)
393 {
394     Log *log(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_THREAD));
395 
396     if (log)
397         log->Printf ("OperatingSystemPython::CreateThread (tid = 0x%" PRIx64 ", context = 0x%" PRIx64 ") fetching register data from python", tid, context);
398 
399     if (m_interpreter && m_python_object_sp)
400     {
401         // First thing we have to do is get the API lock, and the run lock.  We're going to change the thread
402         // content of the process, and we're going to use python, which requires the API lock to do it.
403         // So get & hold that.  This is a recursive lock so we can grant it to any Python code called on the stack below us.
404         Target &target = m_process->GetTarget();
405         Mutex::Locker api_locker (target.GetAPIMutex());
406 
407         auto lock = m_interpreter->AcquireInterpreterLock(); // to make sure thread_info_dict stays alive
408         StructuredData::DictionarySP thread_info_dict = m_interpreter->OSPlugin_CreateThread(m_python_object_sp, tid, context);
409         std::vector<bool> core_used_map;
410         if (thread_info_dict)
411         {
412             ThreadList core_threads(m_process);
413             ThreadList &thread_list = m_process->GetThreadList();
414             bool did_create = false;
415             ThreadSP thread_sp(CreateThreadFromThreadInfo(*thread_info_dict, core_threads, thread_list, core_used_map, &did_create));
416             if (did_create)
417                 thread_list.AddThread(thread_sp);
418             return thread_sp;
419         }
420     }
421     return ThreadSP();
422 }
423 
424 
425 
426 #endif // #ifndef LLDB_DISABLE_PYTHON
427