contrib/llvm/tools/lldb/source/Plugins/OperatingSystem/Python/OperatingSystemPython.cpp

   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 #ifndef LLDB_DISABLE_PYTHON
  10
  11 #include "OperatingSystemPython.h"
  12
  13 #include "Plugins/Process/Utility/DynamicRegisterInfo.h"
  14 #include "Plugins/Process/Utility/RegisterContextDummy.h"
  15 #include "Plugins/Process/Utility/RegisterContextMemory.h"
  16 #include "Plugins/Process/Utility/ThreadMemory.h"
  17 #include "lldb/Core/Debugger.h"
  18 #include "lldb/Core/Module.h"
  19 #include "lldb/Core/PluginManager.h"
  20 #include "lldb/Core/ValueObjectVariable.h"
  21 #include "lldb/Interpreter/CommandInterpreter.h"
  22 #include "lldb/Interpreter/ScriptInterpreter.h"
  23 #include "lldb/Symbol/ObjectFile.h"
  24 #include "lldb/Symbol/VariableList.h"
  25 #include "lldb/Target/Process.h"
  26 #include "lldb/Target/StopInfo.h"
  27 #include "lldb/Target/Target.h"
  28 #include "lldb/Target/Thread.h"
  29 #include "lldb/Target/ThreadList.h"
  30 #include "lldb/Utility/DataBufferHeap.h"
  31 #include "lldb/Utility/RegisterValue.h"
  32 #include "lldb/Utility/StreamString.h"
  33 #include "lldb/Utility/StructuredData.h"
  34
  35 #include <memory>
  36
  37 using namespace lldb;
  38 using namespace lldb_private;
  39
  40 void OperatingSystemPython::Initialize() {
  41   PluginManager::RegisterPlugin(GetPluginNameStatic(),
  42                                 GetPluginDescriptionStatic(), CreateInstance,
  43                                 nullptr);
  44 }
  45
  46 void OperatingSystemPython::Terminate() {
  47   PluginManager::UnregisterPlugin(CreateInstance);
  48 }
  49
  50 OperatingSystem *OperatingSystemPython::CreateInstance(Process *process,
  51                                                        bool force) {
  52   // Python OperatingSystem plug-ins must be requested by name, so force must
  53   // be true
  54   FileSpec python_os_plugin_spec(process->GetPythonOSPluginPath());
  55   if (python_os_plugin_spec &&
  56       FileSystem::Instance().Exists(python_os_plugin_spec)) {
  57     std::unique_ptr<OperatingSystemPython> os_up(
  58         new OperatingSystemPython(process, python_os_plugin_spec));
  59     if (os_up.get() && os_up->IsValid())
  60       return os_up.release();
  61   }
  62   return nullptr;
  63 }
  64
  65 ConstString OperatingSystemPython::GetPluginNameStatic() {
  66   static ConstString g_name("python");
  67   return g_name;
  68 }
  69
  70 const char *OperatingSystemPython::GetPluginDescriptionStatic() {
  71   return "Operating system plug-in that gathers OS information from a python "
  72          "class that implements the necessary OperatingSystem functionality.";
  73 }
  74
  75 OperatingSystemPython::OperatingSystemPython(lldb_private::Process *process,
  76                                              const FileSpec &python_module_path)
  77     : OperatingSystem(process), m_thread_list_valobj_sp(), m_register_info_up(),
  78       m_interpreter(nullptr), m_python_object_sp() {
  79   if (!process)
  80     return;
  81   TargetSP target_sp = process->CalculateTarget();
  82   if (!target_sp)
  83     return;
  84   m_interpreter = target_sp->GetDebugger().GetScriptInterpreter();
  85   if (m_interpreter) {
  86
  87     std::string os_plugin_class_name(
  88         python_module_path.GetFilename().AsCString(""));
  89     if (!os_plugin_class_name.empty()) {
  90       const bool init_session = false;
  91       const bool allow_reload = true;
  92       char python_module_path_cstr[PATH_MAX];
  93       python_module_path.GetPath(python_module_path_cstr,
  94                                  sizeof(python_module_path_cstr));
  95       Status error;
  96       if (m_interpreter->LoadScriptingModule(
  97               python_module_path_cstr, allow_reload, init_session, error)) {
  98         // Strip the ".py" extension if there is one
  99         size_t py_extension_pos = os_plugin_class_name.rfind(".py");
 100         if (py_extension_pos != std::string::npos)
 101           os_plugin_class_name.erase(py_extension_pos);
 102         // Add ".OperatingSystemPlugIn" to the module name to get a string like
 103         // "modulename.OperatingSystemPlugIn"
 104         os_plugin_class_name += ".OperatingSystemPlugIn";
 105         StructuredData::ObjectSP object_sp =
 106             m_interpreter->OSPlugin_CreatePluginObject(
 107                 os_plugin_class_name.c_str(), process->CalculateProcess());
 108         if (object_sp && object_sp->IsValid())
 109           m_python_object_sp = object_sp;
 110       }
 111     }
 112   }
 113 }
 114
 115 OperatingSystemPython::~OperatingSystemPython() {}
 116
 117 DynamicRegisterInfo *OperatingSystemPython::GetDynamicRegisterInfo() {
 118   if (m_register_info_up == nullptr) {
 119     if (!m_interpreter || !m_python_object_sp)
 120       return nullptr;
 121     Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_OS));
 122
 123     if (log)
 124       log->Printf("OperatingSystemPython::GetDynamicRegisterInfo() fetching "
 125                   "thread register definitions from python for pid %" PRIu64,
 126                   m_process->GetID());
 127
 128     StructuredData::DictionarySP dictionary =
 129         m_interpreter->OSPlugin_RegisterInfo(m_python_object_sp);
 130     if (!dictionary)
 131       return nullptr;
 132
 133     m_register_info_up.reset(new DynamicRegisterInfo(
 134         *dictionary, m_process->GetTarget().GetArchitecture()));
 135     assert(m_register_info_up->GetNumRegisters() > 0);
 136     assert(m_register_info_up->GetNumRegisterSets() > 0);
 137   }
 138   return m_register_info_up.get();
 139 }
 140
 141 // PluginInterface protocol
 142 ConstString OperatingSystemPython::GetPluginName() {
 143   return GetPluginNameStatic();
 144 }
 145
 146 uint32_t OperatingSystemPython::GetPluginVersion() { return 1; }
 147
 148 bool OperatingSystemPython::UpdateThreadList(ThreadList &old_thread_list,
 149                                              ThreadList &core_thread_list,
 150                                              ThreadList &new_thread_list) {
 151   if (!m_interpreter || !m_python_object_sp)
 152     return false;
 153
 154   Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_OS));
 155
 156   // First thing we have to do is to try to get the API lock, and the
 157   // interpreter lock. We're going to change the thread content of the process,
 158   // and we're going to use python, which requires the API lock to do it. We
 159   // need the interpreter lock to make sure thread_info_dict stays alive.
 160   //
 161   // If someone already has the API lock, that is ok, we just want to avoid
 162   // external code from making new API calls while this call is happening.
 163   //
 164   // This is a recursive lock so we can grant it to any Python code called on
 165   // the stack below us.
 166   Target &target = m_process->GetTarget();
 167   std::unique_lock<std::recursive_mutex> api_lock(target.GetAPIMutex(),
 168                                                   std::defer_lock);
 169   api_lock.try_lock();
 170   auto interpreter_lock = m_interpreter->AcquireInterpreterLock();
 171
 172   if (log)
 173     log->Printf("OperatingSystemPython::UpdateThreadList() fetching thread "
 174                 "data from python for pid %" PRIu64,
 175                 m_process->GetID());
 176
 177   // The threads that are in "new_thread_list" upon entry are the threads from
 178   // the lldb_private::Process subclass, no memory threads will be in this
 179   // list.
 180   StructuredData::ArraySP threads_list =
 181       m_interpreter->OSPlugin_ThreadsInfo(m_python_object_sp);
 182
 183   const uint32_t num_cores = core_thread_list.GetSize(false);
 184
 185   // Make a map so we can keep track of which cores were used from the
 186   // core_thread list. Any real threads/cores that weren't used should later be
 187   // put back into the "new_thread_list".
 188   std::vector<bool> core_used_map(num_cores, false);
 189   if (threads_list) {
 190     if (log) {
 191       StreamString strm;
 192       threads_list->Dump(strm);
 193       log->Printf("threads_list = %s", strm.GetData());
 194     }
 195
 196     const uint32_t num_threads = threads_list->GetSize();
 197     for (uint32_t i = 0; i < num_threads; ++i) {
 198       StructuredData::ObjectSP thread_dict_obj =
 199           threads_list->GetItemAtIndex(i);
 200       if (auto thread_dict = thread_dict_obj->GetAsDictionary()) {
 201         ThreadSP thread_sp(CreateThreadFromThreadInfo(
 202             *thread_dict, core_thread_list, old_thread_list, core_used_map,
 203             nullptr));
 204         if (thread_sp)
 205           new_thread_list.AddThread(thread_sp);
 206       }
 207     }
 208   }
 209
 210   // Any real core threads that didn't end up backing a memory thread should
 211   // still be in the main thread list, and they should be inserted at the
 212   // beginning of the list
 213   uint32_t insert_idx = 0;
 214   for (uint32_t core_idx = 0; core_idx < num_cores; ++core_idx) {
 215     if (!core_used_map[core_idx]) {
 216       new_thread_list.InsertThread(
 217           core_thread_list.GetThreadAtIndex(core_idx, false), insert_idx);
 218       ++insert_idx;
 219     }
 220   }
 221
 222   return new_thread_list.GetSize(false) > 0;
 223 }
 224
 225 ThreadSP OperatingSystemPython::CreateThreadFromThreadInfo(
 226     StructuredData::Dictionary &thread_dict, ThreadList &core_thread_list,
 227     ThreadList &old_thread_list, std::vector<bool> &core_used_map,
 228     bool *did_create_ptr) {
 229   ThreadSP thread_sp;
 230   tid_t tid = LLDB_INVALID_THREAD_ID;
 231   if (!thread_dict.GetValueForKeyAsInteger("tid", tid))
 232     return ThreadSP();
 233
 234   uint32_t core_number;
 235   addr_t reg_data_addr;
 236   llvm::StringRef name;
 237   llvm::StringRef queue;
 238
 239   thread_dict.GetValueForKeyAsInteger("core", core_number, UINT32_MAX);
 240   thread_dict.GetValueForKeyAsInteger("register_data_addr", reg_data_addr,
 241                                       LLDB_INVALID_ADDRESS);
 242   thread_dict.GetValueForKeyAsString("name", name);
 243   thread_dict.GetValueForKeyAsString("queue", queue);
 244
 245   // See if a thread already exists for "tid"
 246   thread_sp = old_thread_list.FindThreadByID(tid, false);
 247   if (thread_sp) {
 248     // A thread already does exist for "tid", make sure it was an operating
 249     // system
 250     // plug-in generated thread.
 251     if (!IsOperatingSystemPluginThread(thread_sp)) {
 252       // We have thread ID overlap between the protocol threads and the
 253       // operating system threads, clear the thread so we create an operating
 254       // system thread for this.
 255       thread_sp.reset();
 256     }
 257   }
 258
 259   if (!thread_sp) {
 260     if (did_create_ptr)
 261       *did_create_ptr = true;
 262     thread_sp = std::make_shared<ThreadMemory>(*m_process, tid, name, queue,
 263                                                reg_data_addr);
 264   }
 265
 266   if (core_number < core_thread_list.GetSize(false)) {
 267     ThreadSP core_thread_sp(
 268         core_thread_list.GetThreadAtIndex(core_number, false));
 269     if (core_thread_sp) {
 270       // Keep track of which cores were set as the backing thread for memory
 271       // threads...
 272       if (core_number < core_used_map.size())
 273         core_used_map[core_number] = true;
 274
 275       ThreadSP backing_core_thread_sp(core_thread_sp->GetBackingThread());
 276       if (backing_core_thread_sp) {
 277         thread_sp->SetBackingThread(backing_core_thread_sp);
 278       } else {
 279         thread_sp->SetBackingThread(core_thread_sp);
 280       }
 281     }
 282   }
 283   return thread_sp;
 284 }
 285
 286 void OperatingSystemPython::ThreadWasSelected(Thread *thread) {}
 287
 288 RegisterContextSP
 289 OperatingSystemPython::CreateRegisterContextForThread(Thread *thread,
 290                                                       addr_t reg_data_addr) {
 291   RegisterContextSP reg_ctx_sp;
 292   if (!m_interpreter || !m_python_object_sp || !thread)
 293     return reg_ctx_sp;
 294
 295   if (!IsOperatingSystemPluginThread(thread->shared_from_this()))
 296     return reg_ctx_sp;
 297
 298   // First thing we have to do is to try to get the API lock, and the
 299   // interpreter lock. We're going to change the thread content of the process,
 300   // and we're going to use python, which requires the API lock to do it. We
 301   // need the interpreter lock to make sure thread_info_dict stays alive.
 302   //
 303   // If someone already has the API lock, that is ok, we just want to avoid
 304   // external code from making new API calls while this call is happening.
 305   //
 306   // This is a recursive lock so we can grant it to any Python code called on
 307   // the stack below us.
 308   Target &target = m_process->GetTarget();
 309   std::unique_lock<std::recursive_mutex> api_lock(target.GetAPIMutex(),
 310                                                   std::defer_lock);
 311   api_lock.try_lock();
 312   auto interpreter_lock = m_interpreter->AcquireInterpreterLock();
 313
 314   Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_THREAD));
 315
 316   if (reg_data_addr != LLDB_INVALID_ADDRESS) {
 317     // The registers data is in contiguous memory, just create the register
 318     // context using the address provided
 319     if (log)
 320       log->Printf("OperatingSystemPython::CreateRegisterContextForThread (tid "
 321                   "= 0x%" PRIx64 ", 0x%" PRIx64 ", reg_data_addr = 0x%" PRIx64
 322                   ") creating memory register context",
 323                   thread->GetID(), thread->GetProtocolID(), reg_data_addr);
 324     reg_ctx_sp = std::make_shared<RegisterContextMemory>(
 325         *thread, 0, *GetDynamicRegisterInfo(), reg_data_addr);
 326   } else {
 327     // No register data address is provided, query the python plug-in to let it
 328     // make up the data as it sees fit
 329     if (log)
 330       log->Printf("OperatingSystemPython::CreateRegisterContextForThread (tid "
 331                   "= 0x%" PRIx64 ", 0x%" PRIx64
 332                   ") fetching register data from python",
 333                   thread->GetID(), thread->GetProtocolID());
 334
 335     StructuredData::StringSP reg_context_data =
 336         m_interpreter->OSPlugin_RegisterContextData(m_python_object_sp,
 337                                                     thread->GetID());
 338     if (reg_context_data) {
 339       std::string value = reg_context_data->GetValue();
 340       DataBufferSP data_sp(new DataBufferHeap(value.c_str(), value.length()));
 341       if (data_sp->GetByteSize()) {
 342         RegisterContextMemory *reg_ctx_memory = new RegisterContextMemory(
 343             *thread, 0, *GetDynamicRegisterInfo(), LLDB_INVALID_ADDRESS);
 344         if (reg_ctx_memory) {
 345           reg_ctx_sp.reset(reg_ctx_memory);
 346           reg_ctx_memory->SetAllRegisterData(data_sp);
 347         }
 348       }
 349     }
 350   }
 351   // if we still have no register data, fallback on a dummy context to avoid
 352   // crashing
 353   if (!reg_ctx_sp) {
 354     if (log)
 355       log->Printf("OperatingSystemPython::CreateRegisterContextForThread (tid "
 356                   "= 0x%" PRIx64 ") forcing a dummy register context",
 357                   thread->GetID());
 358     reg_ctx_sp = std::make_shared<RegisterContextDummy>(
 359         *thread, 0, target.GetArchitecture().GetAddressByteSize());
 360   }
 361   return reg_ctx_sp;
 362 }
 363
 364 StopInfoSP
 365 OperatingSystemPython::CreateThreadStopReason(lldb_private::Thread *thread) {
 366   // We should have gotten the thread stop info from the dictionary of data for
 367   // the thread in the initial call to get_thread_info(), this should have been
 368   // cached so we can return it here
 369   StopInfoSP
 370       stop_info_sp; //(StopInfo::CreateStopReasonWithSignal (*thread, SIGSTOP));
 371   return stop_info_sp;
 372 }
 373
 374 lldb::ThreadSP OperatingSystemPython::CreateThread(lldb::tid_t tid,
 375                                                    addr_t context) {
 376   Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_THREAD));
 377
 378   if (log)
 379     log->Printf("OperatingSystemPython::CreateThread (tid = 0x%" PRIx64
 380                 ", context = 0x%" PRIx64 ") fetching register data from python",
 381                 tid, context);
 382
 383   if (m_interpreter && m_python_object_sp) {
 384     // First thing we have to do is to try to get the API lock, and the
 385     // interpreter lock. We're going to change the thread content of the
 386     // process, and we're going to use python, which requires the API lock to
 387     // do it. We need the interpreter lock to make sure thread_info_dict stays
 388     // alive.
 389     //
 390     // If someone already has the API lock, that is ok, we just want to avoid
 391     // external code from making new API calls while this call is happening.
 392     //
 393     // This is a recursive lock so we can grant it to any Python code called on
 394     // the stack below us.
 395     Target &target = m_process->GetTarget();
 396     std::unique_lock<std::recursive_mutex> api_lock(target.GetAPIMutex(),
 397                                                     std::defer_lock);
 398     api_lock.try_lock();
 399     auto interpreter_lock = m_interpreter->AcquireInterpreterLock();
 400
 401     StructuredData::DictionarySP thread_info_dict =
 402         m_interpreter->OSPlugin_CreateThread(m_python_object_sp, tid, context);
 403     std::vector<bool> core_used_map;
 404     if (thread_info_dict) {
 405       ThreadList core_threads(m_process);
 406       ThreadList &thread_list = m_process->GetThreadList();
 407       bool did_create = false;
 408       ThreadSP thread_sp(
 409           CreateThreadFromThreadInfo(*thread_info_dict, core_threads,
 410                                      thread_list, core_used_map, &did_create));
 411       if (did_create)
 412         thread_list.AddThread(thread_sp);
 413       return thread_sp;
 414     }
 415   }
 416   return ThreadSP();
 417 }
 418
 419 #endif // #ifndef LLDB_DISABLE_PYTHON