1 //===-- OperatingSystemPython.cpp -----------------------------------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8
9 #include "lldb/Host/Config.h"
10
11 #if LLDB_ENABLE_PYTHON
12
13 #include "OperatingSystemPython.h"
14
15 #include "Plugins/Process/Utility/DynamicRegisterInfo.h"
16 #include "Plugins/Process/Utility/RegisterContextDummy.h"
17 #include "Plugins/Process/Utility/RegisterContextMemory.h"
18 #include "Plugins/Process/Utility/ThreadMemory.h"
19 #include "lldb/Core/Debugger.h"
20 #include "lldb/Core/Module.h"
21 #include "lldb/Core/PluginManager.h"
22 #include "lldb/Core/ValueObjectVariable.h"
23 #include "lldb/Interpreter/CommandInterpreter.h"
24 #include "lldb/Interpreter/ScriptInterpreter.h"
25 #include "lldb/Symbol/ObjectFile.h"
26 #include "lldb/Symbol/VariableList.h"
27 #include "lldb/Target/Process.h"
28 #include "lldb/Target/StopInfo.h"
29 #include "lldb/Target/Target.h"
30 #include "lldb/Target/Thread.h"
31 #include "lldb/Target/ThreadList.h"
32 #include "lldb/Utility/DataBufferHeap.h"
33 #include "lldb/Utility/RegisterValue.h"
34 #include "lldb/Utility/StreamString.h"
35 #include "lldb/Utility/StructuredData.h"
36
37 #include <memory>
38
39 using namespace lldb;
40 using namespace lldb_private;
41
LLDB_PLUGIN_DEFINE(OperatingSystemPython)42 LLDB_PLUGIN_DEFINE(OperatingSystemPython)
43
44 void OperatingSystemPython::Initialize() {
45 PluginManager::RegisterPlugin(GetPluginNameStatic(),
46 GetPluginDescriptionStatic(), CreateInstance,
47 nullptr);
48 }
49
Terminate()50 void OperatingSystemPython::Terminate() {
51 PluginManager::UnregisterPlugin(CreateInstance);
52 }
53
CreateInstance(Process * process,bool force)54 OperatingSystem *OperatingSystemPython::CreateInstance(Process *process,
55 bool force) {
56 // Python OperatingSystem plug-ins must be requested by name, so force must
57 // be true
58 FileSpec python_os_plugin_spec(process->GetPythonOSPluginPath());
59 if (python_os_plugin_spec &&
60 FileSystem::Instance().Exists(python_os_plugin_spec)) {
61 std::unique_ptr<OperatingSystemPython> os_up(
62 new OperatingSystemPython(process, python_os_plugin_spec));
63 if (os_up.get() && os_up->IsValid())
64 return os_up.release();
65 }
66 return nullptr;
67 }
68
GetPluginNameStatic()69 ConstString OperatingSystemPython::GetPluginNameStatic() {
70 static ConstString g_name("python");
71 return g_name;
72 }
73
GetPluginDescriptionStatic()74 const char *OperatingSystemPython::GetPluginDescriptionStatic() {
75 return "Operating system plug-in that gathers OS information from a python "
76 "class that implements the necessary OperatingSystem functionality.";
77 }
78
OperatingSystemPython(lldb_private::Process * process,const FileSpec & python_module_path)79 OperatingSystemPython::OperatingSystemPython(lldb_private::Process *process,
80 const FileSpec &python_module_path)
81 : OperatingSystem(process), m_thread_list_valobj_sp(), m_register_info_up(),
82 m_interpreter(nullptr), m_python_object_sp() {
83 if (!process)
84 return;
85 TargetSP target_sp = process->CalculateTarget();
86 if (!target_sp)
87 return;
88 m_interpreter = target_sp->GetDebugger().GetScriptInterpreter();
89 if (m_interpreter) {
90
91 std::string os_plugin_class_name(
92 python_module_path.GetFilename().AsCString(""));
93 if (!os_plugin_class_name.empty()) {
94 const bool init_session = false;
95 char python_module_path_cstr[PATH_MAX];
96 python_module_path.GetPath(python_module_path_cstr,
97 sizeof(python_module_path_cstr));
98 Status error;
99 if (m_interpreter->LoadScriptingModule(python_module_path_cstr,
100 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
~OperatingSystemPython()118 OperatingSystemPython::~OperatingSystemPython() {}
119
GetDynamicRegisterInfo()120 DynamicRegisterInfo *OperatingSystemPython::GetDynamicRegisterInfo() {
121 if (m_register_info_up == nullptr) {
122 if (!m_interpreter || !m_python_object_sp)
123 return nullptr;
124 Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_OS));
125
126 LLDB_LOGF(log,
127 "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 nullptr;
135
136 m_register_info_up = std::make_unique<DynamicRegisterInfo>(
137 *dictionary, m_process->GetTarget().GetArchitecture());
138 assert(m_register_info_up->GetNumRegisters() > 0);
139 assert(m_register_info_up->GetNumRegisterSets() > 0);
140 }
141 return m_register_info_up.get();
142 }
143
144 // PluginInterface protocol
GetPluginName()145 ConstString OperatingSystemPython::GetPluginName() {
146 return GetPluginNameStatic();
147 }
148
GetPluginVersion()149 uint32_t OperatingSystemPython::GetPluginVersion() { return 1; }
150
UpdateThreadList(ThreadList & old_thread_list,ThreadList & core_thread_list,ThreadList & new_thread_list)151 bool OperatingSystemPython::UpdateThreadList(ThreadList &old_thread_list,
152 ThreadList &core_thread_list,
153 ThreadList &new_thread_list) {
154 if (!m_interpreter || !m_python_object_sp)
155 return false;
156
157 Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_OS));
158
159 // First thing we have to do is to try to get the API lock, and the
160 // interpreter lock. We're going to change the thread content of the process,
161 // and we're going to use python, which requires the API lock to do it. We
162 // need the interpreter lock to make sure thread_info_dict stays alive.
163 //
164 // If someone already has the API lock, that is ok, we just want to avoid
165 // external code from making new API calls while this call is happening.
166 //
167 // This is a recursive lock so we can grant it to any Python code called on
168 // the stack below us.
169 Target &target = m_process->GetTarget();
170 std::unique_lock<std::recursive_mutex> api_lock(target.GetAPIMutex(),
171 std::defer_lock);
172 (void)api_lock.try_lock(); // See above.
173 auto interpreter_lock = m_interpreter->AcquireInterpreterLock();
174
175 LLDB_LOGF(log,
176 "OperatingSystemPython::UpdateThreadList() fetching thread "
177 "data from python for pid %" PRIu64,
178 m_process->GetID());
179
180 // The threads that are in "core_thread_list" upon entry are the threads from
181 // the lldb_private::Process subclass, no memory threads will be in this
182 // list.
183 StructuredData::ArraySP threads_list =
184 m_interpreter->OSPlugin_ThreadsInfo(m_python_object_sp);
185
186 const uint32_t num_cores = core_thread_list.GetSize(false);
187
188 // Make a map so we can keep track of which cores were used from the
189 // core_thread list. Any real threads/cores that weren't used should later be
190 // put back into the "new_thread_list".
191 std::vector<bool> core_used_map(num_cores, false);
192 if (threads_list) {
193 if (log) {
194 StreamString strm;
195 threads_list->Dump(strm);
196 LLDB_LOGF(log, "threads_list = %s", strm.GetData());
197 }
198
199 const uint32_t num_threads = threads_list->GetSize();
200 for (uint32_t i = 0; i < num_threads; ++i) {
201 StructuredData::ObjectSP thread_dict_obj =
202 threads_list->GetItemAtIndex(i);
203 if (auto thread_dict = thread_dict_obj->GetAsDictionary()) {
204 ThreadSP thread_sp(CreateThreadFromThreadInfo(
205 *thread_dict, core_thread_list, old_thread_list, core_used_map,
206 nullptr));
207 if (thread_sp)
208 new_thread_list.AddThread(thread_sp);
209 }
210 }
211 }
212
213 // Any real core threads that didn't end up backing a memory thread should
214 // still be in the main thread list, and they should be inserted at the
215 // beginning of the list
216 uint32_t insert_idx = 0;
217 for (uint32_t core_idx = 0; core_idx < num_cores; ++core_idx) {
218 if (!core_used_map[core_idx]) {
219 new_thread_list.InsertThread(
220 core_thread_list.GetThreadAtIndex(core_idx, false), insert_idx);
221 ++insert_idx;
222 }
223 }
224
225 return new_thread_list.GetSize(false) > 0;
226 }
227
CreateThreadFromThreadInfo(StructuredData::Dictionary & thread_dict,ThreadList & core_thread_list,ThreadList & old_thread_list,std::vector<bool> & core_used_map,bool * did_create_ptr)228 ThreadSP OperatingSystemPython::CreateThreadFromThreadInfo(
229 StructuredData::Dictionary &thread_dict, ThreadList &core_thread_list,
230 ThreadList &old_thread_list, std::vector<bool> &core_used_map,
231 bool *did_create_ptr) {
232 ThreadSP thread_sp;
233 tid_t tid = LLDB_INVALID_THREAD_ID;
234 if (!thread_dict.GetValueForKeyAsInteger("tid", tid))
235 return ThreadSP();
236
237 uint32_t core_number;
238 addr_t reg_data_addr;
239 llvm::StringRef name;
240 llvm::StringRef queue;
241
242 thread_dict.GetValueForKeyAsInteger("core", core_number, UINT32_MAX);
243 thread_dict.GetValueForKeyAsInteger("register_data_addr", reg_data_addr,
244 LLDB_INVALID_ADDRESS);
245 thread_dict.GetValueForKeyAsString("name", name);
246 thread_dict.GetValueForKeyAsString("queue", queue);
247
248 // See if a thread already exists for "tid"
249 thread_sp = old_thread_list.FindThreadByID(tid, false);
250 if (thread_sp) {
251 // A thread already does exist for "tid", make sure it was an operating
252 // system
253 // plug-in generated thread.
254 if (!IsOperatingSystemPluginThread(thread_sp)) {
255 // We have thread ID overlap between the protocol threads and the
256 // operating system threads, clear the thread so we create an operating
257 // system thread for this.
258 thread_sp.reset();
259 }
260 }
261
262 if (!thread_sp) {
263 if (did_create_ptr)
264 *did_create_ptr = true;
265 thread_sp = std::make_shared<ThreadMemory>(*m_process, tid, name, queue,
266 reg_data_addr);
267 }
268
269 if (core_number < core_thread_list.GetSize(false)) {
270 ThreadSP core_thread_sp(
271 core_thread_list.GetThreadAtIndex(core_number, false));
272 if (core_thread_sp) {
273 // Keep track of which cores were set as the backing thread for memory
274 // threads...
275 if (core_number < core_used_map.size())
276 core_used_map[core_number] = true;
277
278 ThreadSP backing_core_thread_sp(core_thread_sp->GetBackingThread());
279 if (backing_core_thread_sp) {
280 thread_sp->SetBackingThread(backing_core_thread_sp);
281 } else {
282 thread_sp->SetBackingThread(core_thread_sp);
283 }
284 }
285 }
286 return thread_sp;
287 }
288
ThreadWasSelected(Thread * thread)289 void OperatingSystemPython::ThreadWasSelected(Thread *thread) {}
290
291 RegisterContextSP
CreateRegisterContextForThread(Thread * thread,addr_t reg_data_addr)292 OperatingSystemPython::CreateRegisterContextForThread(Thread *thread,
293 addr_t reg_data_addr) {
294 RegisterContextSP reg_ctx_sp;
295 if (!m_interpreter || !m_python_object_sp || !thread)
296 return reg_ctx_sp;
297
298 if (!IsOperatingSystemPluginThread(thread->shared_from_this()))
299 return reg_ctx_sp;
300
301 // First thing we have to do is to try to get the API lock, and the
302 // interpreter lock. We're going to change the thread content of the process,
303 // and we're going to use python, which requires the API lock to do it. We
304 // need the interpreter lock to make sure thread_info_dict stays alive.
305 //
306 // If someone already has the API lock, that is ok, we just want to avoid
307 // external code from making new API calls while this call is happening.
308 //
309 // This is a recursive lock so we can grant it to any Python code called on
310 // the stack below us.
311 Target &target = m_process->GetTarget();
312 std::unique_lock<std::recursive_mutex> api_lock(target.GetAPIMutex(),
313 std::defer_lock);
314 (void)api_lock.try_lock(); // See above.
315 auto interpreter_lock = m_interpreter->AcquireInterpreterLock();
316
317 Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_THREAD));
318
319 if (reg_data_addr != LLDB_INVALID_ADDRESS) {
320 // The registers data is in contiguous memory, just create the register
321 // context using the address provided
322 LLDB_LOGF(log,
323 "OperatingSystemPython::CreateRegisterContextForThread (tid "
324 "= 0x%" PRIx64 ", 0x%" PRIx64 ", reg_data_addr = 0x%" PRIx64
325 ") creating memory register context",
326 thread->GetID(), thread->GetProtocolID(), reg_data_addr);
327 reg_ctx_sp = std::make_shared<RegisterContextMemory>(
328 *thread, 0, *GetDynamicRegisterInfo(), reg_data_addr);
329 } else {
330 // No register data address is provided, query the python plug-in to let it
331 // make up the data as it sees fit
332 LLDB_LOGF(log,
333 "OperatingSystemPython::CreateRegisterContextForThread (tid "
334 "= 0x%" PRIx64 ", 0x%" PRIx64
335 ") fetching register data from python",
336 thread->GetID(), thread->GetProtocolID());
337
338 StructuredData::StringSP reg_context_data =
339 m_interpreter->OSPlugin_RegisterContextData(m_python_object_sp,
340 thread->GetID());
341 if (reg_context_data) {
342 std::string value = std::string(reg_context_data->GetValue());
343 DataBufferSP data_sp(new DataBufferHeap(value.c_str(), value.length()));
344 if (data_sp->GetByteSize()) {
345 RegisterContextMemory *reg_ctx_memory = new RegisterContextMemory(
346 *thread, 0, *GetDynamicRegisterInfo(), LLDB_INVALID_ADDRESS);
347 if (reg_ctx_memory) {
348 reg_ctx_sp.reset(reg_ctx_memory);
349 reg_ctx_memory->SetAllRegisterData(data_sp);
350 }
351 }
352 }
353 }
354 // if we still have no register data, fallback on a dummy context to avoid
355 // crashing
356 if (!reg_ctx_sp) {
357 LLDB_LOGF(log,
358 "OperatingSystemPython::CreateRegisterContextForThread (tid "
359 "= 0x%" PRIx64 ") forcing a dummy register context",
360 thread->GetID());
361 reg_ctx_sp = std::make_shared<RegisterContextDummy>(
362 *thread, 0, target.GetArchitecture().GetAddressByteSize());
363 }
364 return reg_ctx_sp;
365 }
366
367 StopInfoSP
CreateThreadStopReason(lldb_private::Thread * thread)368 OperatingSystemPython::CreateThreadStopReason(lldb_private::Thread *thread) {
369 // We should have gotten the thread stop info from the dictionary of data for
370 // the thread in the initial call to get_thread_info(), this should have been
371 // cached so we can return it here
372 StopInfoSP
373 stop_info_sp; //(StopInfo::CreateStopReasonWithSignal (*thread, SIGSTOP));
374 return stop_info_sp;
375 }
376
CreateThread(lldb::tid_t tid,addr_t context)377 lldb::ThreadSP OperatingSystemPython::CreateThread(lldb::tid_t tid,
378 addr_t context) {
379 Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_THREAD));
380
381 LLDB_LOGF(log,
382 "OperatingSystemPython::CreateThread (tid = 0x%" PRIx64
383 ", context = 0x%" PRIx64 ") fetching register data from python",
384 tid, context);
385
386 if (m_interpreter && m_python_object_sp) {
387 // First thing we have to do is to try to get the API lock, and the
388 // interpreter lock. We're going to change the thread content of the
389 // process, and we're going to use python, which requires the API lock to
390 // do it. We need the interpreter lock to make sure thread_info_dict stays
391 // alive.
392 //
393 // If someone already has the API lock, that is ok, we just want to avoid
394 // external code from making new API calls while this call is happening.
395 //
396 // This is a recursive lock so we can grant it to any Python code called on
397 // the stack below us.
398 Target &target = m_process->GetTarget();
399 std::unique_lock<std::recursive_mutex> api_lock(target.GetAPIMutex(),
400 std::defer_lock);
401 (void)api_lock.try_lock(); // See above.
402 auto interpreter_lock = m_interpreter->AcquireInterpreterLock();
403
404 StructuredData::DictionarySP thread_info_dict =
405 m_interpreter->OSPlugin_CreateThread(m_python_object_sp, tid, context);
406 std::vector<bool> core_used_map;
407 if (thread_info_dict) {
408 ThreadList core_threads(m_process);
409 ThreadList &thread_list = m_process->GetThreadList();
410 bool did_create = false;
411 ThreadSP thread_sp(
412 CreateThreadFromThreadInfo(*thread_info_dict, core_threads,
413 thread_list, core_used_map, &did_create));
414 if (did_create)
415 thread_list.AddThread(thread_sp);
416 return thread_sp;
417 }
418 }
419 return ThreadSP();
420 }
421
422 #endif // #if LLDB_ENABLE_PYTHON
423