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