xref: /llvm-project/lldb/source/Plugins/OperatingSystem/Python/OperatingSystemPython.cpp (revision 99558cc424fee346a4070b42ac9c62546d499333)
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/ObjectFile.h"
28 #include "lldb/Symbol/VariableList.h"
29 #include "lldb/Target/Process.h"
30 #include "lldb/Target/StopInfo.h"
31 #include "lldb/Target/Target.h"
32 #include "lldb/Target/ThreadList.h"
33 #include "lldb/Target/Thread.h"
34 #include "Plugins/Process/Utility/DynamicRegisterInfo.h"
35 #include "Plugins/Process/Utility/RegisterContextDummy.h"
36 #include "Plugins/Process/Utility/RegisterContextMemory.h"
37 #include "Plugins/Process/Utility/ThreadMemory.h"
38 
39 using namespace lldb;
40 using namespace lldb_private;
41 
42 void
43 OperatingSystemPython::Initialize()
44 {
45     PluginManager::RegisterPlugin (GetPluginNameStatic(),
46                                    GetPluginDescriptionStatic(),
47                                    CreateInstance);
48 }
49 
50 void
51 OperatingSystemPython::Terminate()
52 {
53     PluginManager::UnregisterPlugin (CreateInstance);
54 }
55 
56 OperatingSystem *
57 OperatingSystemPython::CreateInstance (Process *process, bool force)
58 {
59     // Python OperatingSystem plug-ins must be requested by name, so force must be true
60     FileSpec python_os_plugin_spec (process->GetPythonOSPluginPath());
61     if (python_os_plugin_spec && python_os_plugin_spec.Exists())
62     {
63         std::unique_ptr<OperatingSystemPython> os_ap (new OperatingSystemPython (process, python_os_plugin_spec));
64         if (os_ap.get() && os_ap->IsValid())
65             return os_ap.release();
66     }
67     return NULL;
68 }
69 
70 
71 ConstString
72 OperatingSystemPython::GetPluginNameStatic()
73 {
74     static ConstString g_name("python");
75     return g_name;
76 }
77 
78 const char *
79 OperatingSystemPython::GetPluginDescriptionStatic()
80 {
81     return "Operating system plug-in that gathers OS information from a python class that implements the necessary OperatingSystem functionality.";
82 }
83 
84 
85 OperatingSystemPython::OperatingSystemPython (lldb_private::Process *process, const FileSpec &python_module_path) :
86     OperatingSystem (process),
87     m_thread_list_valobj_sp (),
88     m_register_info_ap (),
89     m_interpreter (NULL),
90     m_python_object_sp ()
91 {
92     if (!process)
93         return;
94     TargetSP target_sp = process->CalculateTarget();
95     if (!target_sp)
96         return;
97     m_interpreter = target_sp->GetDebugger().GetCommandInterpreter().GetScriptInterpreter();
98     if (m_interpreter)
99     {
100 
101         std::string os_plugin_class_name (python_module_path.GetFilename().AsCString(""));
102         if (!os_plugin_class_name.empty())
103         {
104             const bool init_session = false;
105             const bool allow_reload = true;
106             char python_module_path_cstr[PATH_MAX];
107             python_module_path.GetPath(python_module_path_cstr, sizeof(python_module_path_cstr));
108             Error error;
109             if (m_interpreter->LoadScriptingModule (python_module_path_cstr, allow_reload, init_session, error))
110             {
111                 // Strip the ".py" extension if there is one
112                 size_t py_extension_pos = os_plugin_class_name.rfind(".py");
113                 if (py_extension_pos != std::string::npos)
114                     os_plugin_class_name.erase (py_extension_pos);
115                 // Add ".OperatingSystemPlugIn" to the module name to get a string like "modulename.OperatingSystemPlugIn"
116                 os_plugin_class_name += ".OperatingSystemPlugIn";
117                 StructuredData::ObjectSP object_sp =
118                     m_interpreter->OSPlugin_CreatePluginObject(os_plugin_class_name.c_str(), process->CalculateProcess());
119                 if (object_sp && object_sp->IsValid())
120                     m_python_object_sp = object_sp;
121             }
122         }
123     }
124 }
125 
126 OperatingSystemPython::~OperatingSystemPython ()
127 {
128 }
129 
130 DynamicRegisterInfo *
131 OperatingSystemPython::GetDynamicRegisterInfo ()
132 {
133     if (m_register_info_ap.get() == NULL)
134     {
135         if (!m_interpreter || !m_python_object_sp)
136             return NULL;
137         Log *log(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_OS));
138 
139         if (log)
140             log->Printf ("OperatingSystemPython::GetDynamicRegisterInfo() fetching thread register definitions from python for pid %" PRIu64, m_process->GetID());
141 
142         StructuredData::DictionarySP dictionary = m_interpreter->OSPlugin_RegisterInfo(m_python_object_sp);
143         if (!dictionary)
144             return NULL;
145 
146         m_register_info_ap.reset(new DynamicRegisterInfo(*dictionary, m_process->GetTarget().GetArchitecture()));
147         assert (m_register_info_ap->GetNumRegisters() > 0);
148         assert (m_register_info_ap->GetNumRegisterSets() > 0);
149     }
150     return m_register_info_ap.get();
151 }
152 
153 //------------------------------------------------------------------
154 // PluginInterface protocol
155 //------------------------------------------------------------------
156 ConstString
157 OperatingSystemPython::GetPluginName()
158 {
159     return GetPluginNameStatic();
160 }
161 
162 uint32_t
163 OperatingSystemPython::GetPluginVersion()
164 {
165     return 1;
166 }
167 
168 bool
169 OperatingSystemPython::UpdateThreadList (ThreadList &old_thread_list,
170                                          ThreadList &core_thread_list,
171                                          ThreadList &new_thread_list)
172 {
173     if (!m_interpreter || !m_python_object_sp)
174         return false;
175 
176     Log *log(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_OS));
177 
178     // First thing we have to do is to try to get the API lock, and the run lock.
179     // We're going to change the thread content of the process, and we're going
180     // to use python, which requires the API lock to do it.
181     //
182     // If someone already has the API lock, that is ok, we just want to avoid
183     // external code from making new API calls while this call is happening.
184     //
185     // This is a recursive lock so we can grant it to any Python code called on
186     // the stack below us.
187     Target &target = m_process->GetTarget();
188     Mutex::Locker api_locker;
189     api_locker.TryLock(target.GetAPIMutex());
190 
191     if (log)
192         log->Printf ("OperatingSystemPython::UpdateThreadList() fetching thread data from python for pid %" PRIu64, m_process->GetID());
193 
194     // The threads that are in "new_thread_list" upon entry are the threads from the
195     // lldb_private::Process subclass, no memory threads will be in this list.
196 
197     auto lock = m_interpreter->AcquireInterpreterLock(); // to make sure threads_list stays alive
198     StructuredData::ArraySP threads_list = m_interpreter->OSPlugin_ThreadsInfo(m_python_object_sp);
199 
200     const uint32_t num_cores = core_thread_list.GetSize(false);
201 
202     // Make a map so we can keep track of which cores were used from the
203     // core_thread list. Any real threads/cores that weren't used should
204     // later be put back into the "new_thread_list".
205     std::vector<bool> core_used_map(num_cores, false);
206     if (threads_list)
207     {
208         if (log)
209         {
210             StreamString strm;
211             threads_list->Dump(strm);
212             log->Printf("threads_list = %s", strm.GetString().c_str());
213         }
214 
215         const uint32_t num_threads = threads_list->GetSize();
216         for (uint32_t i = 0; i < num_threads; ++i)
217         {
218             StructuredData::ObjectSP thread_dict_obj = threads_list->GetItemAtIndex(i);
219             if (auto thread_dict = thread_dict_obj->GetAsDictionary())
220             {
221                 ThreadSP thread_sp(CreateThreadFromThreadInfo(*thread_dict, core_thread_list, old_thread_list, core_used_map, NULL));
222                 if (thread_sp)
223                     new_thread_list.AddThread(thread_sp);
224             }
225         }
226     }
227 
228     // Any real core threads that didn't end up backing a memory thread should
229     // still be in the main thread list, and they should be inserted at the beginning
230     // of the list
231     uint32_t insert_idx = 0;
232     for (uint32_t core_idx = 0; core_idx < num_cores; ++core_idx)
233     {
234         if (core_used_map[core_idx] == false)
235         {
236             new_thread_list.InsertThread (core_thread_list.GetThreadAtIndex(core_idx, false), insert_idx);
237             ++insert_idx;
238         }
239     }
240 
241     return new_thread_list.GetSize(false) > 0;
242 }
243 
244 ThreadSP
245 OperatingSystemPython::CreateThreadFromThreadInfo(StructuredData::Dictionary &thread_dict, ThreadList &core_thread_list,
246                                                   ThreadList &old_thread_list, std::vector<bool> &core_used_map, bool *did_create_ptr)
247 {
248     ThreadSP thread_sp;
249     tid_t tid = LLDB_INVALID_THREAD_ID;
250     if (!thread_dict.GetValueForKeyAsInteger("tid", tid))
251         return ThreadSP();
252 
253     uint32_t core_number;
254     addr_t reg_data_addr;
255     std::string name;
256     std::string queue;
257 
258     thread_dict.GetValueForKeyAsInteger("core", core_number, UINT32_MAX);
259     thread_dict.GetValueForKeyAsInteger("register_data_addr", reg_data_addr, LLDB_INVALID_ADDRESS);
260     thread_dict.GetValueForKeyAsString("name", name);
261     thread_dict.GetValueForKeyAsString("queue", queue);
262 
263     // See if a thread already exists for "tid"
264     thread_sp = old_thread_list.FindThreadByID(tid, false);
265     if (thread_sp)
266     {
267         // A thread already does exist for "tid", make sure it was an operating system
268         // plug-in generated thread.
269         if (!IsOperatingSystemPluginThread(thread_sp))
270         {
271             // We have thread ID overlap between the protocol threads and the
272             // operating system threads, clear the thread so we create an
273             // operating system thread for this.
274             thread_sp.reset();
275         }
276     }
277 
278     if (!thread_sp)
279     {
280         if (did_create_ptr)
281             *did_create_ptr = true;
282         thread_sp.reset(new ThreadMemory(*m_process, tid, name.c_str(), queue.c_str(), reg_data_addr));
283     }
284 
285     if (core_number < core_thread_list.GetSize(false))
286     {
287         ThreadSP core_thread_sp(core_thread_list.GetThreadAtIndex(core_number, false));
288         if (core_thread_sp)
289         {
290             // Keep track of which cores were set as the backing thread for memory threads...
291             if (core_number < core_used_map.size())
292                 core_used_map[core_number] = true;
293 
294             ThreadSP backing_core_thread_sp(core_thread_sp->GetBackingThread());
295             if (backing_core_thread_sp)
296             {
297                 thread_sp->SetBackingThread(backing_core_thread_sp);
298             }
299             else
300             {
301                 thread_sp->SetBackingThread(core_thread_sp);
302             }
303         }
304     }
305     return thread_sp;
306 }
307 
308 
309 
310 void
311 OperatingSystemPython::ThreadWasSelected (Thread *thread)
312 {
313 }
314 
315 RegisterContextSP
316 OperatingSystemPython::CreateRegisterContextForThread (Thread *thread, addr_t reg_data_addr)
317 {
318     RegisterContextSP reg_ctx_sp;
319     if (!m_interpreter || !m_python_object_sp || !thread)
320         return reg_ctx_sp;
321 
322     if (!IsOperatingSystemPluginThread(thread->shared_from_this()))
323         return reg_ctx_sp;
324 
325     // First thing we have to do is get the API lock, and the run lock.  We're going to change the thread
326     // content of the process, and we're going to use python, which requires the API lock to do it.
327     // So get & hold that.  This is a recursive lock so we can grant it to any Python code called on the stack below us.
328     Target &target = m_process->GetTarget();
329     Mutex::Locker api_locker (target.GetAPIMutex());
330 
331     Log *log(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_THREAD));
332 
333     auto lock = m_interpreter->AcquireInterpreterLock(); // to make sure python objects stays alive
334     if (reg_data_addr != LLDB_INVALID_ADDRESS)
335     {
336         // The registers data is in contiguous memory, just create the register
337         // context using the address provided
338         if (log)
339             log->Printf ("OperatingSystemPython::CreateRegisterContextForThread (tid = 0x%" PRIx64 ", 0x%" PRIx64 ", reg_data_addr = 0x%" PRIx64 ") creating memory register context",
340                          thread->GetID(),
341                          thread->GetProtocolID(),
342                          reg_data_addr);
343         reg_ctx_sp.reset (new RegisterContextMemory (*thread, 0, *GetDynamicRegisterInfo (), reg_data_addr));
344     }
345     else
346     {
347         // No register data address is provided, query the python plug-in to let
348         // it make up the data as it sees fit
349         if (log)
350             log->Printf ("OperatingSystemPython::CreateRegisterContextForThread (tid = 0x%" PRIx64 ", 0x%" PRIx64 ") fetching register data from python",
351                          thread->GetID(),
352                          thread->GetProtocolID());
353 
354         StructuredData::StringSP reg_context_data = m_interpreter->OSPlugin_RegisterContextData(m_python_object_sp, thread->GetID());
355         if (reg_context_data)
356         {
357             std::string value = reg_context_data->GetValue();
358             DataBufferSP data_sp(new DataBufferHeap(value.c_str(), value.length()));
359             if (data_sp->GetByteSize())
360             {
361                 RegisterContextMemory *reg_ctx_memory = new RegisterContextMemory (*thread, 0, *GetDynamicRegisterInfo (), LLDB_INVALID_ADDRESS);
362                 if (reg_ctx_memory)
363                 {
364                     reg_ctx_sp.reset(reg_ctx_memory);
365                     reg_ctx_memory->SetAllRegisterData (data_sp);
366                 }
367             }
368         }
369     }
370     // if we still have no register data, fallback on a dummy context to avoid crashing
371     if (!reg_ctx_sp)
372     {
373         if (log)
374             log->Printf ("OperatingSystemPython::CreateRegisterContextForThread (tid = 0x%" PRIx64 ") forcing a dummy register context", thread->GetID());
375         reg_ctx_sp.reset(new RegisterContextDummy(*thread,0,target.GetArchitecture().GetAddressByteSize()));
376     }
377     return reg_ctx_sp;
378 }
379 
380 StopInfoSP
381 OperatingSystemPython::CreateThreadStopReason (lldb_private::Thread *thread)
382 {
383     // We should have gotten the thread stop info from the dictionary of data for
384     // the thread in the initial call to get_thread_info(), this should have been
385     // cached so we can return it here
386     StopInfoSP stop_info_sp; //(StopInfo::CreateStopReasonWithSignal (*thread, SIGSTOP));
387     return stop_info_sp;
388 }
389 
390 lldb::ThreadSP
391 OperatingSystemPython::CreateThread (lldb::tid_t tid, addr_t context)
392 {
393     Log *log(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_THREAD));
394 
395     if (log)
396         log->Printf ("OperatingSystemPython::CreateThread (tid = 0x%" PRIx64 ", context = 0x%" PRIx64 ") fetching register data from python", tid, context);
397 
398     if (m_interpreter && m_python_object_sp)
399     {
400         // First thing we have to do is get the API lock, and the run lock.  We're going to change the thread
401         // content of the process, and we're going to use python, which requires the API lock to do it.
402         // So get & hold that.  This is a recursive lock so we can grant it to any Python code called on the stack below us.
403         Target &target = m_process->GetTarget();
404         Mutex::Locker api_locker (target.GetAPIMutex());
405 
406         auto lock = m_interpreter->AcquireInterpreterLock(); // to make sure thread_info_dict stays alive
407         StructuredData::DictionarySP thread_info_dict = m_interpreter->OSPlugin_CreateThread(m_python_object_sp, tid, context);
408         std::vector<bool> core_used_map;
409         if (thread_info_dict)
410         {
411             ThreadList core_threads(m_process);
412             ThreadList &thread_list = m_process->GetThreadList();
413             bool did_create = false;
414             ThreadSP thread_sp(CreateThreadFromThreadInfo(*thread_info_dict, core_threads, thread_list, core_used_map, &did_create));
415             if (did_create)
416                 thread_list.AddThread(thread_sp);
417             return thread_sp;
418         }
419     }
420     return ThreadSP();
421 }
422 
423 
424 
425 #endif // #ifndef LLDB_DISABLE_PYTHON
426