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