contrib/llvm/tools/lldb/source/Host/common/NativeProcessProtocol.cpp

   1 //===-- NativeProcessProtocol.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 #include "lldb/Host/common/NativeProcessProtocol.h"
  11 #include "lldb/Core/State.h"
  12 #include "lldb/Host/Host.h"
  13 #include "lldb/Host/common/NativeRegisterContext.h"
  14 #include "lldb/Host/common/NativeThreadProtocol.h"
  15 #include "lldb/Host/common/SoftwareBreakpoint.h"
  16 #include "lldb/Utility/LLDBAssert.h"
  17 #include "lldb/Utility/Log.h"
  18 #include "lldb/lldb-enumerations.h"
  19
  20 using namespace lldb;
  21 using namespace lldb_private;
  22
  23 // -----------------------------------------------------------------------------
  24 // NativeProcessProtocol Members
  25 // -----------------------------------------------------------------------------
  26
  27 NativeProcessProtocol::NativeProcessProtocol(lldb::pid_t pid, int terminal_fd,
  28                                              NativeDelegate &delegate)
  29     : m_pid(pid), m_terminal_fd(terminal_fd) {
  30   bool registered = RegisterNativeDelegate(delegate);
  31   assert(registered);
  32   (void)registered;
  33 }
  34
  35 lldb_private::Status NativeProcessProtocol::Interrupt() {
  36   Status error;
  37 #if !defined(SIGSTOP)
  38   error.SetErrorString("local host does not support signaling");
  39   return error;
  40 #else
  41   return Signal(SIGSTOP);
  42 #endif
  43 }
  44
  45 Status NativeProcessProtocol::IgnoreSignals(llvm::ArrayRef<int> signals) {
  46   m_signals_to_ignore.clear();
  47   m_signals_to_ignore.insert(signals.begin(), signals.end());
  48   return Status();
  49 }
  50
  51 lldb_private::Status
  52 NativeProcessProtocol::GetMemoryRegionInfo(lldb::addr_t load_addr,
  53                                            MemoryRegionInfo &range_info) {
  54   // Default: not implemented.
  55   return Status("not implemented");
  56 }
  57
  58 llvm::Optional<WaitStatus> NativeProcessProtocol::GetExitStatus() {
  59   if (m_state == lldb::eStateExited)
  60     return m_exit_status;
  61
  62   return llvm::None;
  63 }
  64
  65 bool NativeProcessProtocol::SetExitStatus(WaitStatus status,
  66                                           bool bNotifyStateChange) {
  67   Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_PROCESS));
  68   LLDB_LOG(log, "status = {0}, notify = {1}", status, bNotifyStateChange);
  69
  70   // Exit status already set
  71   if (m_state == lldb::eStateExited) {
  72     if (m_exit_status)
  73       LLDB_LOG(log, "exit status already set to {0}", *m_exit_status);
  74     else
  75       LLDB_LOG(log, "state is exited, but status not set");
  76     return false;
  77   }
  78
  79   m_state = lldb::eStateExited;
  80   m_exit_status = status;
  81
  82   if (bNotifyStateChange)
  83     SynchronouslyNotifyProcessStateChanged(lldb::eStateExited);
  84
  85   return true;
  86 }
  87
  88 NativeThreadProtocol *NativeProcessProtocol::GetThreadAtIndex(uint32_t idx) {
  89   std::lock_guard<std::recursive_mutex> guard(m_threads_mutex);
  90   if (idx < m_threads.size())
  91     return m_threads[idx].get();
  92   return nullptr;
  93 }
  94
  95 NativeThreadProtocol *
  96 NativeProcessProtocol::GetThreadByIDUnlocked(lldb::tid_t tid) {
  97   for (const auto &thread : m_threads) {
  98     if (thread->GetID() == tid)
  99       return thread.get();
 100   }
 101   return nullptr;
 102 }
 103
 104 NativeThreadProtocol *NativeProcessProtocol::GetThreadByID(lldb::tid_t tid) {
 105   std::lock_guard<std::recursive_mutex> guard(m_threads_mutex);
 106   return GetThreadByIDUnlocked(tid);
 107 }
 108
 109 bool NativeProcessProtocol::IsAlive() const {
 110   return m_state != eStateDetached && m_state != eStateExited &&
 111          m_state != eStateInvalid && m_state != eStateUnloaded;
 112 }
 113
 114 const NativeWatchpointList::WatchpointMap &
 115 NativeProcessProtocol::GetWatchpointMap() const {
 116   return m_watchpoint_list.GetWatchpointMap();
 117 }
 118
 119 llvm::Optional<std::pair<uint32_t, uint32_t>>
 120 NativeProcessProtocol::GetHardwareDebugSupportInfo() const {
 121   Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_PROCESS));
 122
 123   // get any thread
 124   NativeThreadProtocol *thread(
 125       const_cast<NativeProcessProtocol *>(this)->GetThreadAtIndex(0));
 126   if (!thread) {
 127     LLDB_LOG(log, "failed to find a thread to grab a NativeRegisterContext!");
 128     return llvm::None;
 129   }
 130
 131   NativeRegisterContext &reg_ctx = thread->GetRegisterContext();
 132   return std::make_pair(reg_ctx.NumSupportedHardwareBreakpoints(),
 133                         reg_ctx.NumSupportedHardwareWatchpoints());
 134 }
 135
 136 Status NativeProcessProtocol::SetWatchpoint(lldb::addr_t addr, size_t size,
 137                                             uint32_t watch_flags,
 138                                             bool hardware) {
 139   // This default implementation assumes setting the watchpoint for the process
 140   // will require setting the watchpoint for each of the threads.  Furthermore,
 141   // it will track watchpoints set for the process and will add them to each
 142   // thread that is attached to via the (FIXME implement) OnThreadAttached ()
 143   // method.
 144
 145   Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_PROCESS));
 146
 147   // Update the thread list
 148   UpdateThreads();
 149
 150   // Keep track of the threads we successfully set the watchpoint for.  If one
 151   // of the thread watchpoint setting operations fails, back off and remove the
 152   // watchpoint for all the threads that were successfully set so we get back
 153   // to a consistent state.
 154   std::vector<NativeThreadProtocol *> watchpoint_established_threads;
 155
 156   // Tell each thread to set a watchpoint.  In the event that hardware
 157   // watchpoints are requested but the SetWatchpoint fails, try to set a
 158   // software watchpoint as a fallback.  It's conceivable that if there are
 159   // more threads than hardware watchpoints available, some of the threads will
 160   // fail to set hardware watchpoints while software ones may be available.
 161   std::lock_guard<std::recursive_mutex> guard(m_threads_mutex);
 162   for (const auto &thread : m_threads) {
 163     assert(thread && "thread list should not have a NULL thread!");
 164
 165     Status thread_error =
 166         thread->SetWatchpoint(addr, size, watch_flags, hardware);
 167     if (thread_error.Fail() && hardware) {
 168       // Try software watchpoints since we failed on hardware watchpoint
 169       // setting and we may have just run out of hardware watchpoints.
 170       thread_error = thread->SetWatchpoint(addr, size, watch_flags, false);
 171       if (thread_error.Success())
 172         LLDB_LOG(log,
 173                  "hardware watchpoint requested but software watchpoint set");
 174     }
 175
 176     if (thread_error.Success()) {
 177       // Remember that we set this watchpoint successfully in case we need to
 178       // clear it later.
 179       watchpoint_established_threads.push_back(thread.get());
 180     } else {
 181       // Unset the watchpoint for each thread we successfully set so that we
 182       // get back to a consistent state of "not set" for the watchpoint.
 183       for (auto unwatch_thread_sp : watchpoint_established_threads) {
 184         Status remove_error = unwatch_thread_sp->RemoveWatchpoint(addr);
 185         if (remove_error.Fail())
 186           LLDB_LOG(log, "RemoveWatchpoint failed for pid={0}, tid={1}: {2}",
 187                    GetID(), unwatch_thread_sp->GetID(), remove_error);
 188       }
 189
 190       return thread_error;
 191     }
 192   }
 193   return m_watchpoint_list.Add(addr, size, watch_flags, hardware);
 194 }
 195
 196 Status NativeProcessProtocol::RemoveWatchpoint(lldb::addr_t addr) {
 197   // Update the thread list
 198   UpdateThreads();
 199
 200   Status overall_error;
 201
 202   std::lock_guard<std::recursive_mutex> guard(m_threads_mutex);
 203   for (const auto &thread : m_threads) {
 204     assert(thread && "thread list should not have a NULL thread!");
 205
 206     const Status thread_error = thread->RemoveWatchpoint(addr);
 207     if (thread_error.Fail()) {
 208       // Keep track of the first thread error if any threads fail. We want to
 209       // try to remove the watchpoint from every thread, though, even if one or
 210       // more have errors.
 211       if (!overall_error.Fail())
 212         overall_error = thread_error;
 213     }
 214   }
 215   const Status error = m_watchpoint_list.Remove(addr);
 216   return overall_error.Fail() ? overall_error : error;
 217 }
 218
 219 const HardwareBreakpointMap &
 220 NativeProcessProtocol::GetHardwareBreakpointMap() const {
 221   return m_hw_breakpoints_map;
 222 }
 223
 224 Status NativeProcessProtocol::SetHardwareBreakpoint(lldb::addr_t addr,
 225                                                     size_t size) {
 226   // This default implementation assumes setting a hardware breakpoint for this
 227   // process will require setting same hardware breakpoint for each of its
 228   // existing threads. New thread will do the same once created.
 229   Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_PROCESS));
 230
 231   // Update the thread list
 232   UpdateThreads();
 233
 234   // Exit here if target does not have required hardware breakpoint capability.
 235   auto hw_debug_cap = GetHardwareDebugSupportInfo();
 236
 237   if (hw_debug_cap == llvm::None || hw_debug_cap->first == 0 ||
 238       hw_debug_cap->first <= m_hw_breakpoints_map.size())
 239     return Status("Target does not have required no of hardware breakpoints");
 240
 241   // Vector below stores all thread pointer for which we have we successfully
 242   // set this hardware breakpoint. If any of the current process threads fails
 243   // to set this hardware breakpoint then roll back and remove this breakpoint
 244   // for all the threads that had already set it successfully.
 245   std::vector<NativeThreadProtocol *> breakpoint_established_threads;
 246
 247   // Request to set a hardware breakpoint for each of current process threads.
 248   std::lock_guard<std::recursive_mutex> guard(m_threads_mutex);
 249   for (const auto &thread : m_threads) {
 250     assert(thread && "thread list should not have a NULL thread!");
 251
 252     Status thread_error = thread->SetHardwareBreakpoint(addr, size);
 253     if (thread_error.Success()) {
 254       // Remember that we set this breakpoint successfully in case we need to
 255       // clear it later.
 256       breakpoint_established_threads.push_back(thread.get());
 257     } else {
 258       // Unset the breakpoint for each thread we successfully set so that we
 259       // get back to a consistent state of "not set" for this hardware
 260       // breakpoint.
 261       for (auto rollback_thread_sp : breakpoint_established_threads) {
 262         Status remove_error =
 263             rollback_thread_sp->RemoveHardwareBreakpoint(addr);
 264         if (remove_error.Fail())
 265           LLDB_LOG(log,
 266                    "RemoveHardwareBreakpoint failed for pid={0}, tid={1}: {2}",
 267                    GetID(), rollback_thread_sp->GetID(), remove_error);
 268       }
 269
 270       return thread_error;
 271     }
 272   }
 273
 274   // Register new hardware breakpoint into hardware breakpoints map of current
 275   // process.
 276   m_hw_breakpoints_map[addr] = {addr, size};
 277
 278   return Status();
 279 }
 280
 281 Status NativeProcessProtocol::RemoveHardwareBreakpoint(lldb::addr_t addr) {
 282   // Update the thread list
 283   UpdateThreads();
 284
 285   Status error;
 286
 287   std::lock_guard<std::recursive_mutex> guard(m_threads_mutex);
 288   for (const auto &thread : m_threads) {
 289     assert(thread && "thread list should not have a NULL thread!");
 290     error = thread->RemoveHardwareBreakpoint(addr);
 291   }
 292
 293   // Also remove from hardware breakpoint map of current process.
 294   m_hw_breakpoints_map.erase(addr);
 295
 296   return error;
 297 }
 298
 299 bool NativeProcessProtocol::RegisterNativeDelegate(
 300     NativeDelegate &native_delegate) {
 301   std::lock_guard<std::recursive_mutex> guard(m_delegates_mutex);
 302   if (std::find(m_delegates.begin(), m_delegates.end(), &native_delegate) !=
 303       m_delegates.end())
 304     return false;
 305
 306   m_delegates.push_back(&native_delegate);
 307   native_delegate.InitializeDelegate(this);
 308   return true;
 309 }
 310
 311 bool NativeProcessProtocol::UnregisterNativeDelegate(
 312     NativeDelegate &native_delegate) {
 313   std::lock_guard<std::recursive_mutex> guard(m_delegates_mutex);
 314
 315   const auto initial_size = m_delegates.size();
 316   m_delegates.erase(
 317       remove(m_delegates.begin(), m_delegates.end(), &native_delegate),
 318       m_delegates.end());
 319
 320   // We removed the delegate if the count of delegates shrank after removing
 321   // all copies of the given native_delegate from the vector.
 322   return m_delegates.size() < initial_size;
 323 }
 324
 325 void NativeProcessProtocol::SynchronouslyNotifyProcessStateChanged(
 326     lldb::StateType state) {
 327   Log *log(GetLogIfAllCategoriesSet(LIBLLDB_LOG_PROCESS));
 328
 329   std::lock_guard<std::recursive_mutex> guard(m_delegates_mutex);
 330   for (auto native_delegate : m_delegates)
 331     native_delegate->ProcessStateChanged(this, state);
 332
 333   if (log) {
 334     if (!m_delegates.empty()) {
 335       log->Printf("NativeProcessProtocol::%s: sent state notification [%s] "
 336                   "from process %" PRIu64,
 337                   __FUNCTION__, lldb_private::StateAsCString(state), GetID());
 338     } else {
 339       log->Printf("NativeProcessProtocol::%s: would send state notification "
 340                   "[%s] from process %" PRIu64 ", but no delegates",
 341                   __FUNCTION__, lldb_private::StateAsCString(state), GetID());
 342     }
 343   }
 344 }
 345
 346 void NativeProcessProtocol::NotifyDidExec() {
 347   Log *log(GetLogIfAllCategoriesSet(LIBLLDB_LOG_PROCESS));
 348   if (log)
 349     log->Printf("NativeProcessProtocol::%s - preparing to call delegates",
 350                 __FUNCTION__);
 351
 352   {
 353     std::lock_guard<std::recursive_mutex> guard(m_delegates_mutex);
 354     for (auto native_delegate : m_delegates)
 355       native_delegate->DidExec(this);
 356   }
 357 }
 358
 359 Status NativeProcessProtocol::SetSoftwareBreakpoint(lldb::addr_t addr,
 360                                                     uint32_t size_hint) {
 361   Log *log(GetLogIfAnyCategoriesSet(LIBLLDB_LOG_BREAKPOINTS));
 362   if (log)
 363     log->Printf("NativeProcessProtocol::%s addr = 0x%" PRIx64, __FUNCTION__,
 364                 addr);
 365
 366   return m_breakpoint_list.AddRef(
 367       addr, size_hint, false,
 368       [this](lldb::addr_t addr, size_t size_hint, bool /* hardware */,
 369              NativeBreakpointSP &breakpoint_sp) -> Status {
 370         return SoftwareBreakpoint::CreateSoftwareBreakpoint(
 371             *this, addr, size_hint, breakpoint_sp);
 372       });
 373 }
 374
 375 Status NativeProcessProtocol::RemoveBreakpoint(lldb::addr_t addr,
 376                                                bool hardware) {
 377   if (hardware)
 378     return RemoveHardwareBreakpoint(addr);
 379   else
 380     return m_breakpoint_list.DecRef(addr);
 381 }
 382
 383 Status NativeProcessProtocol::EnableBreakpoint(lldb::addr_t addr) {
 384   return m_breakpoint_list.EnableBreakpoint(addr);
 385 }
 386
 387 Status NativeProcessProtocol::DisableBreakpoint(lldb::addr_t addr) {
 388   return m_breakpoint_list.DisableBreakpoint(addr);
 389 }
 390
 391 lldb::StateType NativeProcessProtocol::GetState() const {
 392   std::lock_guard<std::recursive_mutex> guard(m_state_mutex);
 393   return m_state;
 394 }
 395
 396 void NativeProcessProtocol::SetState(lldb::StateType state,
 397                                      bool notify_delegates) {
 398   std::lock_guard<std::recursive_mutex> guard(m_state_mutex);
 399
 400   if (state == m_state)
 401     return;
 402
 403   m_state = state;
 404
 405   if (StateIsStoppedState(state, false)) {
 406     ++m_stop_id;
 407
 408     // Give process a chance to do any stop id bump processing, such as
 409     // clearing cached data that is invalidated each time the process runs.
 410     // Note if/when we support some threads running, we'll end up needing to
 411     // manage this per thread and per process.
 412     DoStopIDBumped(m_stop_id);
 413   }
 414
 415   // Optionally notify delegates of the state change.
 416   if (notify_delegates)
 417     SynchronouslyNotifyProcessStateChanged(state);
 418 }
 419
 420 uint32_t NativeProcessProtocol::GetStopID() const {
 421   std::lock_guard<std::recursive_mutex> guard(m_state_mutex);
 422   return m_stop_id;
 423 }
 424
 425 void NativeProcessProtocol::DoStopIDBumped(uint32_t /* newBumpId */) {
 426   // Default implementation does nothing.
 427 }
 428
 429 NativeProcessProtocol::Factory::~Factory() = default;