xref: /llvm-project/lldb/source/Plugins/OperatingSystem/Python/OperatingSystemPython.cpp (revision bb19a13c0b3fe1ecdc1e46bbf2b06ffc1e25e04e)
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(), GetPluginDescriptionStatic(), CreateInstance, nullptr);
46 }
47 
48 void
49 OperatingSystemPython::Terminate()
50 {
51     PluginManager::UnregisterPlugin (CreateInstance);
52 }
53 
54 OperatingSystem *
55 OperatingSystemPython::CreateInstance (Process *process, bool force)
56 {
57     // Python OperatingSystem plug-ins must be requested by name, so force must be true
58     FileSpec python_os_plugin_spec (process->GetPythonOSPluginPath());
59     if (python_os_plugin_spec && python_os_plugin_spec.Exists())
60     {
61         std::unique_ptr<OperatingSystemPython> os_ap (new OperatingSystemPython (process, python_os_plugin_spec));
62         if (os_ap.get() && os_ap->IsValid())
63             return os_ap.release();
64     }
65     return NULL;
66 }
67 
68 
69 ConstString
70 OperatingSystemPython::GetPluginNameStatic()
71 {
72     static ConstString g_name("python");
73     return g_name;
74 }
75 
76 const char *
77 OperatingSystemPython::GetPluginDescriptionStatic()
78 {
79     return "Operating system plug-in that gathers OS information from a python class that implements the necessary OperatingSystem functionality.";
80 }
81 
82 
83 OperatingSystemPython::OperatingSystemPython (lldb_private::Process *process, const FileSpec &python_module_path) :
84     OperatingSystem (process),
85     m_thread_list_valobj_sp (),
86     m_register_info_ap (),
87     m_interpreter (NULL),
88     m_python_object_sp ()
89 {
90     if (!process)
91         return;
92     TargetSP target_sp = process->CalculateTarget();
93     if (!target_sp)
94         return;
95     m_interpreter = target_sp->GetDebugger().GetCommandInterpreter().GetScriptInterpreter();
96     if (m_interpreter)
97     {
98 
99         std::string os_plugin_class_name (python_module_path.GetFilename().AsCString(""));
100         if (!os_plugin_class_name.empty())
101         {
102             const bool init_session = false;
103             const bool allow_reload = true;
104             char python_module_path_cstr[PATH_MAX];
105             python_module_path.GetPath(python_module_path_cstr, sizeof(python_module_path_cstr));
106             Error error;
107             if (m_interpreter->LoadScriptingModule (python_module_path_cstr, allow_reload, init_session, error))
108             {
109                 // Strip the ".py" extension if there is one
110                 size_t py_extension_pos = os_plugin_class_name.rfind(".py");
111                 if (py_extension_pos != std::string::npos)
112                     os_plugin_class_name.erase (py_extension_pos);
113                 // Add ".OperatingSystemPlugIn" to the module name to get a string like "modulename.OperatingSystemPlugIn"
114                 os_plugin_class_name += ".OperatingSystemPlugIn";
115                 StructuredData::ObjectSP object_sp =
116                     m_interpreter->OSPlugin_CreatePluginObject(os_plugin_class_name.c_str(), process->CalculateProcess());
117                 if (object_sp && object_sp->IsValid())
118                     m_python_object_sp = object_sp;
119             }
120         }
121     }
122 }
123 
124 OperatingSystemPython::~OperatingSystemPython ()
125 {
126 }
127 
128 DynamicRegisterInfo *
129 OperatingSystemPython::GetDynamicRegisterInfo ()
130 {
131     if (m_register_info_ap.get() == NULL)
132     {
133         if (!m_interpreter || !m_python_object_sp)
134             return NULL;
135         Log *log(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_OS));
136 
137         if (log)
138             log->Printf ("OperatingSystemPython::GetDynamicRegisterInfo() fetching thread register definitions from python for pid %" PRIu64, m_process->GetID());
139 
140         StructuredData::DictionarySP dictionary = m_interpreter->OSPlugin_RegisterInfo(m_python_object_sp);
141         if (!dictionary)
142             return NULL;
143 
144         m_register_info_ap.reset(new DynamicRegisterInfo(*dictionary, m_process->GetTarget().GetArchitecture()));
145         assert (m_register_info_ap->GetNumRegisters() > 0);
146         assert (m_register_info_ap->GetNumRegisterSets() > 0);
147     }
148     return m_register_info_ap.get();
149 }
150 
151 //------------------------------------------------------------------
152 // PluginInterface protocol
153 //------------------------------------------------------------------
154 ConstString
155 OperatingSystemPython::GetPluginName()
156 {
157     return GetPluginNameStatic();
158 }
159 
160 uint32_t
161 OperatingSystemPython::GetPluginVersion()
162 {
163     return 1;
164 }
165 
166 bool
167 OperatingSystemPython::UpdateThreadList (ThreadList &old_thread_list,
168                                          ThreadList &core_thread_list,
169                                          ThreadList &new_thread_list)
170 {
171     if (!m_interpreter || !m_python_object_sp)
172         return false;
173 
174     Log *log(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_OS));
175 
176     // First thing we have to do is to try to get the API lock, and the run lock.
177     // We're going to change the thread content of the process, and we're going
178     // to use python, which requires the API lock to do it.
179     //
180     // If someone already has the API lock, that is ok, we just want to avoid
181     // external code from making new API calls while this call is happening.
182     //
183     // This is a recursive lock so we can grant it to any Python code called on
184     // the stack below us.
185     Target &target = m_process->GetTarget();
186     std::unique_lock<std::recursive_mutex> lock(target.GetAPIMutex(), std::defer_lock);
187     lock.try_lock();
188 
189     if (log)
190         log->Printf ("OperatingSystemPython::UpdateThreadList() fetching thread data from python for pid %" PRIu64, m_process->GetID());
191 
192     // The threads that are in "new_thread_list" upon entry are the threads from the
193     // lldb_private::Process subclass, no memory threads will be in this list.
194 
195     auto interpreter_lock = m_interpreter->AcquireInterpreterLock(); // to make sure threads_list stays alive
196     StructuredData::ArraySP threads_list = m_interpreter->OSPlugin_ThreadsInfo(m_python_object_sp);
197 
198     const uint32_t num_cores = core_thread_list.GetSize(false);
199 
200     // Make a map so we can keep track of which cores were used from the
201     // core_thread list. Any real threads/cores that weren't used should
202     // later be put back into the "new_thread_list".
203     std::vector<bool> core_used_map(num_cores, false);
204     if (threads_list)
205     {
206         if (log)
207         {
208             StreamString strm;
209             threads_list->Dump(strm);
210             log->Printf("threads_list = %s", strm.GetString().c_str());
211         }
212 
213         const uint32_t num_threads = threads_list->GetSize();
214         for (uint32_t i = 0; i < num_threads; ++i)
215         {
216             StructuredData::ObjectSP thread_dict_obj = threads_list->GetItemAtIndex(i);
217             if (auto thread_dict = thread_dict_obj->GetAsDictionary())
218             {
219                 ThreadSP thread_sp(CreateThreadFromThreadInfo(*thread_dict, core_thread_list, old_thread_list, core_used_map, NULL));
220                 if (thread_sp)
221                     new_thread_list.AddThread(thread_sp);
222             }
223         }
224     }
225 
226     // Any real core threads that didn't end up backing a memory thread should
227     // still be in the main thread list, and they should be inserted at the beginning
228     // of the list
229     uint32_t insert_idx = 0;
230     for (uint32_t core_idx = 0; core_idx < num_cores; ++core_idx)
231     {
232         if (core_used_map[core_idx] == false)
233         {
234             new_thread_list.InsertThread (core_thread_list.GetThreadAtIndex(core_idx, false), insert_idx);
235             ++insert_idx;
236         }
237     }
238 
239     return new_thread_list.GetSize(false) > 0;
240 }
241 
242 ThreadSP
243 OperatingSystemPython::CreateThreadFromThreadInfo(StructuredData::Dictionary &thread_dict, ThreadList &core_thread_list,
244                                                   ThreadList &old_thread_list, std::vector<bool> &core_used_map, bool *did_create_ptr)
245 {
246     ThreadSP thread_sp;
247     tid_t tid = LLDB_INVALID_THREAD_ID;
248     if (!thread_dict.GetValueForKeyAsInteger("tid", tid))
249         return ThreadSP();
250 
251     uint32_t core_number;
252     addr_t reg_data_addr;
253     std::string name;
254     std::string queue;
255 
256     thread_dict.GetValueForKeyAsInteger("core", core_number, UINT32_MAX);
257     thread_dict.GetValueForKeyAsInteger("register_data_addr", reg_data_addr, LLDB_INVALID_ADDRESS);
258     thread_dict.GetValueForKeyAsString("name", name);
259     thread_dict.GetValueForKeyAsString("queue", queue);
260 
261     // See if a thread already exists for "tid"
262     thread_sp = old_thread_list.FindThreadByID(tid, false);
263     if (thread_sp)
264     {
265         // A thread already does exist for "tid", make sure it was an operating system
266         // plug-in generated thread.
267         if (!IsOperatingSystemPluginThread(thread_sp))
268         {
269             // We have thread ID overlap between the protocol threads and the
270             // operating system threads, clear the thread so we create an
271             // operating system thread for this.
272             thread_sp.reset();
273         }
274     }
275 
276     if (!thread_sp)
277     {
278         if (did_create_ptr)
279             *did_create_ptr = true;
280         thread_sp.reset(new ThreadMemory(*m_process, tid, name.c_str(), queue.c_str(), reg_data_addr));
281     }
282 
283     if (core_number < core_thread_list.GetSize(false))
284     {
285         ThreadSP core_thread_sp(core_thread_list.GetThreadAtIndex(core_number, false));
286         if (core_thread_sp)
287         {
288             // Keep track of which cores were set as the backing thread for memory threads...
289             if (core_number < core_used_map.size())
290                 core_used_map[core_number] = true;
291 
292             ThreadSP backing_core_thread_sp(core_thread_sp->GetBackingThread());
293             if (backing_core_thread_sp)
294             {
295                 thread_sp->SetBackingThread(backing_core_thread_sp);
296             }
297             else
298             {
299                 thread_sp->SetBackingThread(core_thread_sp);
300             }
301         }
302     }
303     return thread_sp;
304 }
305 
306 
307 
308 void
309 OperatingSystemPython::ThreadWasSelected (Thread *thread)
310 {
311 }
312 
313 RegisterContextSP
314 OperatingSystemPython::CreateRegisterContextForThread (Thread *thread, addr_t reg_data_addr)
315 {
316     RegisterContextSP reg_ctx_sp;
317     if (!m_interpreter || !m_python_object_sp || !thread)
318         return reg_ctx_sp;
319 
320     if (!IsOperatingSystemPluginThread(thread->shared_from_this()))
321         return reg_ctx_sp;
322 
323     // First thing we have to do is get the API lock, and the run lock.  We're going to change the thread
324     // content of the process, and we're going to use python, which requires the API lock to do it.
325     // So get & hold that.  This is a recursive lock so we can grant it to any Python code called on the stack below us.
326     Target &target = m_process->GetTarget();
327     std::lock_guard<std::recursive_mutex> guard(target.GetAPIMutex());
328 
329     Log *log(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_THREAD));
330 
331     auto lock = m_interpreter->AcquireInterpreterLock(); // to make sure python objects stays alive
332     if (reg_data_addr != LLDB_INVALID_ADDRESS)
333     {
334         // The registers data is in contiguous memory, just create the register
335         // context using the address provided
336         if (log)
337             log->Printf ("OperatingSystemPython::CreateRegisterContextForThread (tid = 0x%" PRIx64 ", 0x%" PRIx64 ", reg_data_addr = 0x%" PRIx64 ") creating memory register context",
338                          thread->GetID(),
339                          thread->GetProtocolID(),
340                          reg_data_addr);
341         reg_ctx_sp.reset (new RegisterContextMemory (*thread, 0, *GetDynamicRegisterInfo (), reg_data_addr));
342     }
343     else
344     {
345         // No register data address is provided, query the python plug-in to let
346         // it make up the data as it sees fit
347         if (log)
348             log->Printf ("OperatingSystemPython::CreateRegisterContextForThread (tid = 0x%" PRIx64 ", 0x%" PRIx64 ") fetching register data from python",
349                          thread->GetID(),
350                          thread->GetProtocolID());
351 
352         StructuredData::StringSP reg_context_data = m_interpreter->OSPlugin_RegisterContextData(m_python_object_sp, thread->GetID());
353         if (reg_context_data)
354         {
355             std::string value = reg_context_data->GetValue();
356             DataBufferSP data_sp(new DataBufferHeap(value.c_str(), value.length()));
357             if (data_sp->GetByteSize())
358             {
359                 RegisterContextMemory *reg_ctx_memory = new RegisterContextMemory (*thread, 0, *GetDynamicRegisterInfo (), LLDB_INVALID_ADDRESS);
360                 if (reg_ctx_memory)
361                 {
362                     reg_ctx_sp.reset(reg_ctx_memory);
363                     reg_ctx_memory->SetAllRegisterData (data_sp);
364                 }
365             }
366         }
367     }
368     // if we still have no register data, fallback on a dummy context to avoid crashing
369     if (!reg_ctx_sp)
370     {
371         if (log)
372             log->Printf ("OperatingSystemPython::CreateRegisterContextForThread (tid = 0x%" PRIx64 ") forcing a dummy register context", thread->GetID());
373         reg_ctx_sp.reset(new RegisterContextDummy(*thread,0,target.GetArchitecture().GetAddressByteSize()));
374     }
375     return reg_ctx_sp;
376 }
377 
378 StopInfoSP
379 OperatingSystemPython::CreateThreadStopReason (lldb_private::Thread *thread)
380 {
381     // We should have gotten the thread stop info from the dictionary of data for
382     // the thread in the initial call to get_thread_info(), this should have been
383     // cached so we can return it here
384     StopInfoSP stop_info_sp; //(StopInfo::CreateStopReasonWithSignal (*thread, SIGSTOP));
385     return stop_info_sp;
386 }
387 
388 lldb::ThreadSP
389 OperatingSystemPython::CreateThread (lldb::tid_t tid, addr_t context)
390 {
391     Log *log(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_THREAD));
392 
393     if (log)
394         log->Printf ("OperatingSystemPython::CreateThread (tid = 0x%" PRIx64 ", context = 0x%" PRIx64 ") fetching register data from python", tid, context);
395 
396     if (m_interpreter && m_python_object_sp)
397     {
398         // First thing we have to do is get the API lock, and the run lock.  We're going to change the thread
399         // content of the process, and we're going to use python, which requires the API lock to do it.
400         // So get & hold that.  This is a recursive lock so we can grant it to any Python code called on the stack below us.
401         Target &target = m_process->GetTarget();
402         std::lock_guard<std::recursive_mutex> guard(target.GetAPIMutex());
403 
404         auto lock = m_interpreter->AcquireInterpreterLock(); // to make sure thread_info_dict stays alive
405         StructuredData::DictionarySP thread_info_dict = m_interpreter->OSPlugin_CreateThread(m_python_object_sp, tid, context);
406         std::vector<bool> core_used_map;
407         if (thread_info_dict)
408         {
409             ThreadList core_threads(m_process);
410             ThreadList &thread_list = m_process->GetThreadList();
411             bool did_create = false;
412             ThreadSP thread_sp(CreateThreadFromThreadInfo(*thread_info_dict, core_threads, thread_list, core_used_map, &did_create));
413             if (did_create)
414                 thread_list.AddThread(thread_sp);
415             return thread_sp;
416         }
417     }
418     return ThreadSP();
419 }
420 
421 
422 
423 #endif // #ifndef LLDB_DISABLE_PYTHON
424