1 //===-- ProcessKDP.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 <cerrno>
10 #include <cstdlib>
11 
12 #include <memory>
13 #include <mutex>
14 
15 #include "lldb/Core/Debugger.h"
16 #include "lldb/Core/Module.h"
17 #include "lldb/Core/ModuleSpec.h"
18 #include "lldb/Core/PluginManager.h"
19 #include "lldb/Host/ConnectionFileDescriptor.h"
20 #include "lldb/Host/Host.h"
21 #include "lldb/Host/ThreadLauncher.h"
22 #include "lldb/Host/common/TCPSocket.h"
23 #include "lldb/Interpreter/CommandInterpreter.h"
24 #include "lldb/Interpreter/CommandObject.h"
25 #include "lldb/Interpreter/CommandObjectMultiword.h"
26 #include "lldb/Interpreter/CommandReturnObject.h"
27 #include "lldb/Interpreter/OptionGroupString.h"
28 #include "lldb/Interpreter/OptionGroupUInt64.h"
29 #include "lldb/Interpreter/OptionValueProperties.h"
30 #include "lldb/Symbol/LocateSymbolFile.h"
31 #include "lldb/Symbol/ObjectFile.h"
32 #include "lldb/Target/RegisterContext.h"
33 #include "lldb/Target/Target.h"
34 #include "lldb/Target/Thread.h"
35 #include "lldb/Utility/Log.h"
36 #include "lldb/Utility/State.h"
37 #include "lldb/Utility/StringExtractor.h"
38 #include "lldb/Utility/UUID.h"
39 
40 #include "llvm/Support/Threading.h"
41 
42 #define USEC_PER_SEC 1000000
43 
44 #include "Plugins/DynamicLoader/Darwin-Kernel/DynamicLoaderDarwinKernel.h"
45 #include "Plugins/DynamicLoader/Static/DynamicLoaderStatic.h"
46 #include "ProcessKDP.h"
47 #include "ProcessKDPLog.h"
48 #include "ThreadKDP.h"
49 
50 using namespace lldb;
51 using namespace lldb_private;
52 
53 LLDB_PLUGIN_DEFINE_ADV(ProcessKDP, ProcessMacOSXKernel)
54 
55 namespace {
56 
57 #define LLDB_PROPERTIES_processkdp
58 #include "ProcessKDPProperties.inc"
59 
60 enum {
61 #define LLDB_PROPERTIES_processkdp
62 #include "ProcessKDPPropertiesEnum.inc"
63 };
64 
65 class PluginProperties : public Properties {
66 public:
67   static ConstString GetSettingName() {
68     return ConstString(ProcessKDP::GetPluginNameStatic());
69   }
70 
71   PluginProperties() : Properties() {
72     m_collection_sp = std::make_shared<OptionValueProperties>(GetSettingName());
73     m_collection_sp->Initialize(g_processkdp_properties);
74   }
75 
76   virtual ~PluginProperties() = default;
77 
78   uint64_t GetPacketTimeout() {
79     const uint32_t idx = ePropertyKDPPacketTimeout;
80     return m_collection_sp->GetPropertyAtIndexAsUInt64(
81         NULL, idx, g_processkdp_properties[idx].default_uint_value);
82   }
83 };
84 
85 static PluginProperties &GetGlobalPluginProperties() {
86   static PluginProperties g_settings;
87   return g_settings;
88 }
89 
90 } // anonymous namespace end
91 
92 static const lldb::tid_t g_kernel_tid = 1;
93 
94 llvm::StringRef ProcessKDP::GetPluginDescriptionStatic() {
95   return "KDP Remote protocol based debugging plug-in for darwin kernel "
96          "debugging.";
97 }
98 
99 void ProcessKDP::Terminate() {
100   PluginManager::UnregisterPlugin(ProcessKDP::CreateInstance);
101 }
102 
103 lldb::ProcessSP ProcessKDP::CreateInstance(TargetSP target_sp,
104                                            ListenerSP listener_sp,
105                                            const FileSpec *crash_file_path,
106                                            bool can_connect) {
107   lldb::ProcessSP process_sp;
108   if (crash_file_path == NULL)
109     process_sp = std::make_shared<ProcessKDP>(target_sp, listener_sp);
110   return process_sp;
111 }
112 
113 bool ProcessKDP::CanDebug(TargetSP target_sp, bool plugin_specified_by_name) {
114   if (plugin_specified_by_name)
115     return true;
116 
117   // For now we are just making sure the file exists for a given module
118   Module *exe_module = target_sp->GetExecutableModulePointer();
119   if (exe_module) {
120     const llvm::Triple &triple_ref = target_sp->GetArchitecture().GetTriple();
121     switch (triple_ref.getOS()) {
122     case llvm::Triple::Darwin: // Should use "macosx" for desktop and "ios" for
123                                // iOS, but accept darwin just in case
124     case llvm::Triple::MacOSX: // For desktop targets
125     case llvm::Triple::IOS:    // For arm targets
126     case llvm::Triple::TvOS:
127     case llvm::Triple::WatchOS:
128       if (triple_ref.getVendor() == llvm::Triple::Apple) {
129         ObjectFile *exe_objfile = exe_module->GetObjectFile();
130         if (exe_objfile->GetType() == ObjectFile::eTypeExecutable &&
131             exe_objfile->GetStrata() == ObjectFile::eStrataKernel)
132           return true;
133       }
134       break;
135 
136     default:
137       break;
138     }
139   }
140   return false;
141 }
142 
143 // ProcessKDP constructor
144 ProcessKDP::ProcessKDP(TargetSP target_sp, ListenerSP listener_sp)
145     : Process(target_sp, listener_sp),
146       m_comm("lldb.process.kdp-remote.communication"),
147       m_async_broadcaster(NULL, "lldb.process.kdp-remote.async-broadcaster"),
148       m_kernel_load_addr(LLDB_INVALID_ADDRESS), m_command_sp(),
149       m_kernel_thread_wp() {
150   m_async_broadcaster.SetEventName(eBroadcastBitAsyncThreadShouldExit,
151                                    "async thread should exit");
152   m_async_broadcaster.SetEventName(eBroadcastBitAsyncContinue,
153                                    "async thread continue");
154   const uint64_t timeout_seconds =
155       GetGlobalPluginProperties().GetPacketTimeout();
156   if (timeout_seconds > 0)
157     m_comm.SetPacketTimeout(std::chrono::seconds(timeout_seconds));
158 }
159 
160 // Destructor
161 ProcessKDP::~ProcessKDP() {
162   Clear();
163   // We need to call finalize on the process before destroying ourselves to
164   // make sure all of the broadcaster cleanup goes as planned. If we destruct
165   // this class, then Process::~Process() might have problems trying to fully
166   // destroy the broadcaster.
167   Finalize();
168 }
169 
170 Status ProcessKDP::WillLaunch(Module *module) {
171   Status error;
172   error.SetErrorString("launching not supported in kdp-remote plug-in");
173   return error;
174 }
175 
176 Status ProcessKDP::WillAttachToProcessWithID(lldb::pid_t pid) {
177   Status error;
178   error.SetErrorString(
179       "attaching to a by process ID not supported in kdp-remote plug-in");
180   return error;
181 }
182 
183 Status ProcessKDP::WillAttachToProcessWithName(const char *process_name,
184                                                bool wait_for_launch) {
185   Status error;
186   error.SetErrorString(
187       "attaching to a by process name not supported in kdp-remote plug-in");
188   return error;
189 }
190 
191 bool ProcessKDP::GetHostArchitecture(ArchSpec &arch) {
192   uint32_t cpu = m_comm.GetCPUType();
193   if (cpu) {
194     uint32_t sub = m_comm.GetCPUSubtype();
195     arch.SetArchitecture(eArchTypeMachO, cpu, sub);
196     // Leave architecture vendor as unspecified unknown
197     arch.GetTriple().setVendor(llvm::Triple::UnknownVendor);
198     arch.GetTriple().setVendorName(llvm::StringRef());
199     return true;
200   }
201   arch.Clear();
202   return false;
203 }
204 
205 Status ProcessKDP::DoConnectRemote(llvm::StringRef remote_url) {
206   Status error;
207 
208   // Don't let any JIT happen when doing KDP as we can't allocate memory and we
209   // don't want to be mucking with threads that might already be handling
210   // exceptions
211   SetCanJIT(false);
212 
213   if (remote_url.empty()) {
214     error.SetErrorStringWithFormat("empty connection URL");
215     return error;
216   }
217 
218   std::unique_ptr<ConnectionFileDescriptor> conn_up(
219       new ConnectionFileDescriptor());
220   if (conn_up) {
221     // Only try once for now.
222     // TODO: check if we should be retrying?
223     const uint32_t max_retry_count = 1;
224     for (uint32_t retry_count = 0; retry_count < max_retry_count;
225          ++retry_count) {
226       if (conn_up->Connect(remote_url, &error) == eConnectionStatusSuccess)
227         break;
228       usleep(100000);
229     }
230   }
231 
232   if (conn_up->IsConnected()) {
233     const TCPSocket &socket =
234         static_cast<const TCPSocket &>(*conn_up->GetReadObject());
235     const uint16_t reply_port = socket.GetLocalPortNumber();
236 
237     if (reply_port != 0) {
238       m_comm.SetConnection(std::move(conn_up));
239 
240       if (m_comm.SendRequestReattach(reply_port)) {
241         if (m_comm.SendRequestConnect(reply_port, reply_port,
242                                       "Greetings from LLDB...")) {
243           m_comm.GetVersion();
244 
245           Target &target = GetTarget();
246           ArchSpec kernel_arch;
247           // The host architecture
248           GetHostArchitecture(kernel_arch);
249           ArchSpec target_arch = target.GetArchitecture();
250           // Merge in any unspecified stuff into the target architecture in
251           // case the target arch isn't set at all or incompletely.
252           target_arch.MergeFrom(kernel_arch);
253           target.SetArchitecture(target_arch);
254 
255           /* Get the kernel's UUID and load address via KDP_KERNELVERSION
256            * packet.  */
257           /* An EFI kdp session has neither UUID nor load address. */
258 
259           UUID kernel_uuid = m_comm.GetUUID();
260           addr_t kernel_load_addr = m_comm.GetLoadAddress();
261 
262           if (m_comm.RemoteIsEFI()) {
263             // Select an invalid plugin name for the dynamic loader so one
264             // doesn't get used since EFI does its own manual loading via
265             // python scripting
266             m_dyld_plugin_name = "none";
267 
268             if (kernel_uuid.IsValid()) {
269               // If EFI passed in a UUID= try to lookup UUID The slide will not
270               // be provided. But the UUID lookup will be used to launch EFI
271               // debug scripts from the dSYM, that can load all of the symbols.
272               ModuleSpec module_spec;
273               module_spec.GetUUID() = kernel_uuid;
274               module_spec.GetArchitecture() = target.GetArchitecture();
275 
276               // Lookup UUID locally, before attempting dsymForUUID like action
277               FileSpecList search_paths =
278                   Target::GetDefaultDebugFileSearchPaths();
279               module_spec.GetSymbolFileSpec() =
280                   Symbols::LocateExecutableSymbolFile(module_spec,
281                                                       search_paths);
282               if (module_spec.GetSymbolFileSpec()) {
283                 ModuleSpec executable_module_spec =
284                     Symbols::LocateExecutableObjectFile(module_spec);
285                 if (FileSystem::Instance().Exists(
286                         executable_module_spec.GetFileSpec())) {
287                   module_spec.GetFileSpec() =
288                       executable_module_spec.GetFileSpec();
289                 }
290               }
291               if (!module_spec.GetSymbolFileSpec() ||
292                   !module_spec.GetSymbolFileSpec())
293                 Symbols::DownloadObjectAndSymbolFile(module_spec, true);
294 
295               if (FileSystem::Instance().Exists(module_spec.GetFileSpec())) {
296                 ModuleSP module_sp(new Module(module_spec));
297                 if (module_sp.get() && module_sp->GetObjectFile()) {
298                   // Get the current target executable
299                   ModuleSP exe_module_sp(target.GetExecutableModule());
300 
301                   // Make sure you don't already have the right module loaded
302                   // and they will be uniqued
303                   if (exe_module_sp.get() != module_sp.get())
304                     target.SetExecutableModule(module_sp, eLoadDependentsNo);
305                 }
306               }
307             }
308           } else if (m_comm.RemoteIsDarwinKernel()) {
309             m_dyld_plugin_name =
310                 DynamicLoaderDarwinKernel::GetPluginNameStatic();
311             if (kernel_load_addr != LLDB_INVALID_ADDRESS) {
312               m_kernel_load_addr = kernel_load_addr;
313             }
314           }
315 
316           // Set the thread ID
317           UpdateThreadListIfNeeded();
318           SetID(1);
319           GetThreadList();
320           SetPrivateState(eStateStopped);
321           StreamSP async_strm_sp(target.GetDebugger().GetAsyncOutputStream());
322           if (async_strm_sp) {
323             const char *cstr;
324             if ((cstr = m_comm.GetKernelVersion()) != NULL) {
325               async_strm_sp->Printf("Version: %s\n", cstr);
326               async_strm_sp->Flush();
327             }
328             //                      if ((cstr = m_comm.GetImagePath ()) != NULL)
329             //                      {
330             //                          async_strm_sp->Printf ("Image Path:
331             //                          %s\n", cstr);
332             //                          async_strm_sp->Flush();
333             //                      }
334           }
335         } else {
336           error.SetErrorString("KDP_REATTACH failed");
337         }
338       } else {
339         error.SetErrorString("KDP_REATTACH failed");
340       }
341     } else {
342       error.SetErrorString("invalid reply port from UDP connection");
343     }
344   } else {
345     if (error.Success())
346       error.SetErrorStringWithFormat("failed to connect to '%s'",
347                                      remote_url.str().c_str());
348   }
349   if (error.Fail())
350     m_comm.Disconnect();
351 
352   return error;
353 }
354 
355 // Process Control
356 Status ProcessKDP::DoLaunch(Module *exe_module,
357                             ProcessLaunchInfo &launch_info) {
358   Status error;
359   error.SetErrorString("launching not supported in kdp-remote plug-in");
360   return error;
361 }
362 
363 Status
364 ProcessKDP::DoAttachToProcessWithID(lldb::pid_t attach_pid,
365                                     const ProcessAttachInfo &attach_info) {
366   Status error;
367   error.SetErrorString(
368       "attach to process by ID is not supported in kdp remote debugging");
369   return error;
370 }
371 
372 Status
373 ProcessKDP::DoAttachToProcessWithName(const char *process_name,
374                                       const ProcessAttachInfo &attach_info) {
375   Status error;
376   error.SetErrorString(
377       "attach to process by name is not supported in kdp remote debugging");
378   return error;
379 }
380 
381 void ProcessKDP::DidAttach(ArchSpec &process_arch) {
382   Process::DidAttach(process_arch);
383 
384   Log *log(ProcessKDPLog::GetLogIfAllCategoriesSet(KDP_LOG_PROCESS));
385   LLDB_LOGF(log, "ProcessKDP::DidAttach()");
386   if (GetID() != LLDB_INVALID_PROCESS_ID) {
387     GetHostArchitecture(process_arch);
388   }
389 }
390 
391 addr_t ProcessKDP::GetImageInfoAddress() { return m_kernel_load_addr; }
392 
393 lldb_private::DynamicLoader *ProcessKDP::GetDynamicLoader() {
394   if (m_dyld_up.get() == NULL)
395     m_dyld_up.reset(DynamicLoader::FindPlugin(this, m_dyld_plugin_name));
396   return m_dyld_up.get();
397 }
398 
399 Status ProcessKDP::WillResume() { return Status(); }
400 
401 Status ProcessKDP::DoResume() {
402   Status error;
403   Log *log(ProcessKDPLog::GetLogIfAllCategoriesSet(KDP_LOG_PROCESS));
404   // Only start the async thread if we try to do any process control
405   if (!m_async_thread.IsJoinable())
406     StartAsyncThread();
407 
408   bool resume = false;
409 
410   // With KDP there is only one thread we can tell what to do
411   ThreadSP kernel_thread_sp(m_thread_list.FindThreadByProtocolID(g_kernel_tid));
412 
413   if (kernel_thread_sp) {
414     const StateType thread_resume_state =
415         kernel_thread_sp->GetTemporaryResumeState();
416 
417     LLDB_LOGF(log, "ProcessKDP::DoResume() thread_resume_state = %s",
418               StateAsCString(thread_resume_state));
419     switch (thread_resume_state) {
420     case eStateSuspended:
421       // Nothing to do here when a thread will stay suspended we just leave the
422       // CPU mask bit set to zero for the thread
423       LLDB_LOGF(log, "ProcessKDP::DoResume() = suspended???");
424       break;
425 
426     case eStateStepping: {
427       lldb::RegisterContextSP reg_ctx_sp(
428           kernel_thread_sp->GetRegisterContext());
429 
430       if (reg_ctx_sp) {
431         LLDB_LOGF(
432             log,
433             "ProcessKDP::DoResume () reg_ctx_sp->HardwareSingleStep (true);");
434         reg_ctx_sp->HardwareSingleStep(true);
435         resume = true;
436       } else {
437         error.SetErrorStringWithFormat(
438             "KDP thread 0x%llx has no register context",
439             kernel_thread_sp->GetID());
440       }
441     } break;
442 
443     case eStateRunning: {
444       lldb::RegisterContextSP reg_ctx_sp(
445           kernel_thread_sp->GetRegisterContext());
446 
447       if (reg_ctx_sp) {
448         LLDB_LOGF(log, "ProcessKDP::DoResume () reg_ctx_sp->HardwareSingleStep "
449                        "(false);");
450         reg_ctx_sp->HardwareSingleStep(false);
451         resume = true;
452       } else {
453         error.SetErrorStringWithFormat(
454             "KDP thread 0x%llx has no register context",
455             kernel_thread_sp->GetID());
456       }
457     } break;
458 
459     default:
460       // The only valid thread resume states are listed above
461       llvm_unreachable("invalid thread resume state");
462     }
463   }
464 
465   if (resume) {
466     LLDB_LOGF(log, "ProcessKDP::DoResume () sending resume");
467 
468     if (m_comm.SendRequestResume()) {
469       m_async_broadcaster.BroadcastEvent(eBroadcastBitAsyncContinue);
470       SetPrivateState(eStateRunning);
471     } else
472       error.SetErrorString("KDP resume failed");
473   } else {
474     error.SetErrorString("kernel thread is suspended");
475   }
476 
477   return error;
478 }
479 
480 lldb::ThreadSP ProcessKDP::GetKernelThread() {
481   // KDP only tells us about one thread/core. Any other threads will usually
482   // be the ones that are read from memory by the OS plug-ins.
483 
484   ThreadSP thread_sp(m_kernel_thread_wp.lock());
485   if (!thread_sp) {
486     thread_sp = std::make_shared<ThreadKDP>(*this, g_kernel_tid);
487     m_kernel_thread_wp = thread_sp;
488   }
489   return thread_sp;
490 }
491 
492 bool ProcessKDP::DoUpdateThreadList(ThreadList &old_thread_list,
493                                     ThreadList &new_thread_list) {
494   // locker will keep a mutex locked until it goes out of scope
495   Log *log(ProcessKDPLog::GetLogIfAllCategoriesSet(KDP_LOG_THREAD));
496   LLDB_LOGV(log, "pid = {0}", GetID());
497 
498   // Even though there is a CPU mask, it doesn't mean we can see each CPU
499   // individually, there is really only one. Lets call this thread 1.
500   ThreadSP thread_sp(
501       old_thread_list.FindThreadByProtocolID(g_kernel_tid, false));
502   if (!thread_sp)
503     thread_sp = GetKernelThread();
504   new_thread_list.AddThread(thread_sp);
505 
506   return new_thread_list.GetSize(false) > 0;
507 }
508 
509 void ProcessKDP::RefreshStateAfterStop() {
510   // Let all threads recover from stopping and do any clean up based on the
511   // previous thread state (if any).
512   m_thread_list.RefreshStateAfterStop();
513 }
514 
515 Status ProcessKDP::DoHalt(bool &caused_stop) {
516   Status error;
517 
518   if (m_comm.IsRunning()) {
519     if (m_destroy_in_process) {
520       // If we are attempting to destroy, we need to not return an error to Halt
521       // or DoDestroy won't get called. We are also currently running, so send
522       // a process stopped event
523       SetPrivateState(eStateStopped);
524     } else {
525       error.SetErrorString("KDP cannot interrupt a running kernel");
526     }
527   }
528   return error;
529 }
530 
531 Status ProcessKDP::DoDetach(bool keep_stopped) {
532   Status error;
533   Log *log(ProcessKDPLog::GetLogIfAllCategoriesSet(KDP_LOG_PROCESS));
534   LLDB_LOGF(log, "ProcessKDP::DoDetach(keep_stopped = %i)", keep_stopped);
535 
536   if (m_comm.IsRunning()) {
537     // We are running and we can't interrupt a running kernel, so we need to
538     // just close the connection to the kernel and hope for the best
539   } else {
540     // If we are going to keep the target stopped, then don't send the
541     // disconnect message.
542     if (!keep_stopped && m_comm.IsConnected()) {
543       const bool success = m_comm.SendRequestDisconnect();
544       if (log) {
545         if (success)
546           log->PutCString(
547               "ProcessKDP::DoDetach() detach packet sent successfully");
548         else
549           log->PutCString(
550               "ProcessKDP::DoDetach() connection channel shutdown failed");
551       }
552       m_comm.Disconnect();
553     }
554   }
555   StopAsyncThread();
556   m_comm.Clear();
557 
558   SetPrivateState(eStateDetached);
559   ResumePrivateStateThread();
560 
561   // KillDebugserverProcess ();
562   return error;
563 }
564 
565 Status ProcessKDP::DoDestroy() {
566   // For KDP there really is no difference between destroy and detach
567   bool keep_stopped = false;
568   return DoDetach(keep_stopped);
569 }
570 
571 // Process Queries
572 
573 bool ProcessKDP::IsAlive() {
574   return m_comm.IsConnected() && Process::IsAlive();
575 }
576 
577 // Process Memory
578 size_t ProcessKDP::DoReadMemory(addr_t addr, void *buf, size_t size,
579                                 Status &error) {
580   uint8_t *data_buffer = (uint8_t *)buf;
581   if (m_comm.IsConnected()) {
582     const size_t max_read_size = 512;
583     size_t total_bytes_read = 0;
584 
585     // Read the requested amount of memory in 512 byte chunks
586     while (total_bytes_read < size) {
587       size_t bytes_to_read_this_request = size - total_bytes_read;
588       if (bytes_to_read_this_request > max_read_size) {
589         bytes_to_read_this_request = max_read_size;
590       }
591       size_t bytes_read = m_comm.SendRequestReadMemory(
592           addr + total_bytes_read, data_buffer + total_bytes_read,
593           bytes_to_read_this_request, error);
594       total_bytes_read += bytes_read;
595       if (error.Fail() || bytes_read == 0) {
596         return total_bytes_read;
597       }
598     }
599 
600     return total_bytes_read;
601   }
602   error.SetErrorString("not connected");
603   return 0;
604 }
605 
606 size_t ProcessKDP::DoWriteMemory(addr_t addr, const void *buf, size_t size,
607                                  Status &error) {
608   if (m_comm.IsConnected())
609     return m_comm.SendRequestWriteMemory(addr, buf, size, error);
610   error.SetErrorString("not connected");
611   return 0;
612 }
613 
614 lldb::addr_t ProcessKDP::DoAllocateMemory(size_t size, uint32_t permissions,
615                                           Status &error) {
616   error.SetErrorString(
617       "memory allocation not supported in kdp remote debugging");
618   return LLDB_INVALID_ADDRESS;
619 }
620 
621 Status ProcessKDP::DoDeallocateMemory(lldb::addr_t addr) {
622   Status error;
623   error.SetErrorString(
624       "memory deallocation not supported in kdp remote debugging");
625   return error;
626 }
627 
628 Status ProcessKDP::EnableBreakpointSite(BreakpointSite *bp_site) {
629   if (bp_site->HardwareRequired())
630     return Status("Hardware breakpoints are not supported.");
631 
632   if (m_comm.LocalBreakpointsAreSupported()) {
633     Status error;
634     if (!bp_site->IsEnabled()) {
635       if (m_comm.SendRequestBreakpoint(true, bp_site->GetLoadAddress())) {
636         bp_site->SetEnabled(true);
637         bp_site->SetType(BreakpointSite::eExternal);
638       } else {
639         error.SetErrorString("KDP set breakpoint failed");
640       }
641     }
642     return error;
643   }
644   return EnableSoftwareBreakpoint(bp_site);
645 }
646 
647 Status ProcessKDP::DisableBreakpointSite(BreakpointSite *bp_site) {
648   if (m_comm.LocalBreakpointsAreSupported()) {
649     Status error;
650     if (bp_site->IsEnabled()) {
651       BreakpointSite::Type bp_type = bp_site->GetType();
652       if (bp_type == BreakpointSite::eExternal) {
653         if (m_destroy_in_process && m_comm.IsRunning()) {
654           // We are trying to destroy our connection and we are running
655           bp_site->SetEnabled(false);
656         } else {
657           if (m_comm.SendRequestBreakpoint(false, bp_site->GetLoadAddress()))
658             bp_site->SetEnabled(false);
659           else
660             error.SetErrorString("KDP remove breakpoint failed");
661         }
662       } else {
663         error = DisableSoftwareBreakpoint(bp_site);
664       }
665     }
666     return error;
667   }
668   return DisableSoftwareBreakpoint(bp_site);
669 }
670 
671 Status ProcessKDP::EnableWatchpoint(Watchpoint *wp, bool notify) {
672   Status error;
673   error.SetErrorString(
674       "watchpoints are not supported in kdp remote debugging");
675   return error;
676 }
677 
678 Status ProcessKDP::DisableWatchpoint(Watchpoint *wp, bool notify) {
679   Status error;
680   error.SetErrorString(
681       "watchpoints are not supported in kdp remote debugging");
682   return error;
683 }
684 
685 void ProcessKDP::Clear() { m_thread_list.Clear(); }
686 
687 Status ProcessKDP::DoSignal(int signo) {
688   Status error;
689   error.SetErrorString(
690       "sending signals is not supported in kdp remote debugging");
691   return error;
692 }
693 
694 void ProcessKDP::Initialize() {
695   static llvm::once_flag g_once_flag;
696 
697   llvm::call_once(g_once_flag, []() {
698     PluginManager::RegisterPlugin(GetPluginNameStatic(),
699                                   GetPluginDescriptionStatic(), CreateInstance,
700                                   DebuggerInitialize);
701 
702     ProcessKDPLog::Initialize();
703   });
704 }
705 
706 void ProcessKDP::DebuggerInitialize(lldb_private::Debugger &debugger) {
707   if (!PluginManager::GetSettingForProcessPlugin(
708           debugger, PluginProperties::GetSettingName())) {
709     const bool is_global_setting = true;
710     PluginManager::CreateSettingForProcessPlugin(
711         debugger, GetGlobalPluginProperties().GetValueProperties(),
712         ConstString("Properties for the kdp-remote process plug-in."),
713         is_global_setting);
714   }
715 }
716 
717 bool ProcessKDP::StartAsyncThread() {
718   Log *log(ProcessKDPLog::GetLogIfAllCategoriesSet(KDP_LOG_PROCESS));
719 
720   LLDB_LOGF(log, "ProcessKDP::StartAsyncThread ()");
721 
722   if (m_async_thread.IsJoinable())
723     return true;
724 
725   llvm::Expected<HostThread> async_thread = ThreadLauncher::LaunchThread(
726       "<lldb.process.kdp-remote.async>", ProcessKDP::AsyncThread, this);
727   if (!async_thread) {
728     LLDB_LOG(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_HOST),
729              "failed to launch host thread: {}",
730              llvm::toString(async_thread.takeError()));
731     return false;
732   }
733   m_async_thread = *async_thread;
734   return m_async_thread.IsJoinable();
735 }
736 
737 void ProcessKDP::StopAsyncThread() {
738   Log *log(ProcessKDPLog::GetLogIfAllCategoriesSet(KDP_LOG_PROCESS));
739 
740   LLDB_LOGF(log, "ProcessKDP::StopAsyncThread ()");
741 
742   m_async_broadcaster.BroadcastEvent(eBroadcastBitAsyncThreadShouldExit);
743 
744   // Stop the stdio thread
745   if (m_async_thread.IsJoinable())
746     m_async_thread.Join(nullptr);
747 }
748 
749 void *ProcessKDP::AsyncThread(void *arg) {
750   ProcessKDP *process = (ProcessKDP *)arg;
751 
752   const lldb::pid_t pid = process->GetID();
753 
754   Log *log(ProcessKDPLog::GetLogIfAllCategoriesSet(KDP_LOG_PROCESS));
755   LLDB_LOGF(log,
756             "ProcessKDP::AsyncThread (arg = %p, pid = %" PRIu64
757             ") thread starting...",
758             arg, pid);
759 
760   ListenerSP listener_sp(Listener::MakeListener("ProcessKDP::AsyncThread"));
761   EventSP event_sp;
762   const uint32_t desired_event_mask =
763       eBroadcastBitAsyncContinue | eBroadcastBitAsyncThreadShouldExit;
764 
765   if (listener_sp->StartListeningForEvents(&process->m_async_broadcaster,
766                                            desired_event_mask) ==
767       desired_event_mask) {
768     bool done = false;
769     while (!done) {
770       LLDB_LOGF(log,
771                 "ProcessKDP::AsyncThread (pid = %" PRIu64
772                 ") listener.WaitForEvent (NULL, event_sp)...",
773                 pid);
774       if (listener_sp->GetEvent(event_sp, llvm::None)) {
775         uint32_t event_type = event_sp->GetType();
776         LLDB_LOGF(log,
777                   "ProcessKDP::AsyncThread (pid = %" PRIu64
778                   ") Got an event of type: %d...",
779                   pid, event_type);
780 
781         // When we are running, poll for 1 second to try and get an exception
782         // to indicate the process has stopped. If we don't get one, check to
783         // make sure no one asked us to exit
784         bool is_running = false;
785         DataExtractor exc_reply_packet;
786         do {
787           switch (event_type) {
788           case eBroadcastBitAsyncContinue: {
789             is_running = true;
790             if (process->m_comm.WaitForPacketWithTimeoutMicroSeconds(
791                     exc_reply_packet, 1 * USEC_PER_SEC)) {
792               ThreadSP thread_sp(process->GetKernelThread());
793               if (thread_sp) {
794                 lldb::RegisterContextSP reg_ctx_sp(
795                     thread_sp->GetRegisterContext());
796                 if (reg_ctx_sp)
797                   reg_ctx_sp->InvalidateAllRegisters();
798                 static_cast<ThreadKDP *>(thread_sp.get())
799                     ->SetStopInfoFrom_KDP_EXCEPTION(exc_reply_packet);
800               }
801 
802               // TODO: parse the stop reply packet
803               is_running = false;
804               process->SetPrivateState(eStateStopped);
805             } else {
806               // Check to see if we are supposed to exit. There is no way to
807               // interrupt a running kernel, so all we can do is wait for an
808               // exception or detach...
809               if (listener_sp->GetEvent(event_sp,
810                                         std::chrono::microseconds(0))) {
811                 // We got an event, go through the loop again
812                 event_type = event_sp->GetType();
813               }
814             }
815           } break;
816 
817           case eBroadcastBitAsyncThreadShouldExit:
818             LLDB_LOGF(log,
819                       "ProcessKDP::AsyncThread (pid = %" PRIu64
820                       ") got eBroadcastBitAsyncThreadShouldExit...",
821                       pid);
822             done = true;
823             is_running = false;
824             break;
825 
826           default:
827             LLDB_LOGF(log,
828                       "ProcessKDP::AsyncThread (pid = %" PRIu64
829                       ") got unknown event 0x%8.8x",
830                       pid, event_type);
831             done = true;
832             is_running = false;
833             break;
834           }
835         } while (is_running);
836       } else {
837         LLDB_LOGF(log,
838                   "ProcessKDP::AsyncThread (pid = %" PRIu64
839                   ") listener.WaitForEvent (NULL, event_sp) => false",
840                   pid);
841         done = true;
842       }
843     }
844   }
845 
846   LLDB_LOGF(log,
847             "ProcessKDP::AsyncThread (arg = %p, pid = %" PRIu64
848             ") thread exiting...",
849             arg, pid);
850 
851   process->m_async_thread.Reset();
852   return NULL;
853 }
854 
855 class CommandObjectProcessKDPPacketSend : public CommandObjectParsed {
856 private:
857   OptionGroupOptions m_option_group;
858   OptionGroupUInt64 m_command_byte;
859   OptionGroupString m_packet_data;
860 
861   Options *GetOptions() override { return &m_option_group; }
862 
863 public:
864   CommandObjectProcessKDPPacketSend(CommandInterpreter &interpreter)
865       : CommandObjectParsed(interpreter, "process plugin packet send",
866                             "Send a custom packet through the KDP protocol by "
867                             "specifying the command byte and the packet "
868                             "payload data. A packet will be sent with a "
869                             "correct header and payload, and the raw result "
870                             "bytes will be displayed as a string value. ",
871                             NULL),
872         m_option_group(),
873         m_command_byte(LLDB_OPT_SET_1, true, "command", 'c', 0, eArgTypeNone,
874                        "Specify the command byte to use when sending the KDP "
875                        "request packet.",
876                        0),
877         m_packet_data(LLDB_OPT_SET_1, false, "payload", 'p', 0, eArgTypeNone,
878                       "Specify packet payload bytes as a hex ASCII string with "
879                       "no spaces or hex prefixes.",
880                       NULL) {
881     m_option_group.Append(&m_command_byte, LLDB_OPT_SET_ALL, LLDB_OPT_SET_1);
882     m_option_group.Append(&m_packet_data, LLDB_OPT_SET_ALL, LLDB_OPT_SET_1);
883     m_option_group.Finalize();
884   }
885 
886   ~CommandObjectProcessKDPPacketSend() = default;
887 
888   bool DoExecute(Args &command, CommandReturnObject &result) override {
889     const size_t argc = command.GetArgumentCount();
890     if (argc == 0) {
891       if (!m_command_byte.GetOptionValue().OptionWasSet()) {
892         result.AppendError(
893             "the --command option must be set to a valid command byte");
894       } else {
895         const uint64_t command_byte =
896             m_command_byte.GetOptionValue().GetUInt64Value(0);
897         if (command_byte > 0 && command_byte <= UINT8_MAX) {
898           ProcessKDP *process =
899               (ProcessKDP *)m_interpreter.GetExecutionContext().GetProcessPtr();
900           if (process) {
901             const StateType state = process->GetState();
902 
903             if (StateIsStoppedState(state, true)) {
904               std::vector<uint8_t> payload_bytes;
905               const char *ascii_hex_bytes_cstr =
906                   m_packet_data.GetOptionValue().GetCurrentValue();
907               if (ascii_hex_bytes_cstr && ascii_hex_bytes_cstr[0]) {
908                 StringExtractor extractor(ascii_hex_bytes_cstr);
909                 const size_t ascii_hex_bytes_cstr_len =
910                     extractor.GetStringRef().size();
911                 if (ascii_hex_bytes_cstr_len & 1) {
912                   result.AppendErrorWithFormat("payload data must contain an "
913                                                "even number of ASCII hex "
914                                                "characters: '%s'",
915                                                ascii_hex_bytes_cstr);
916                   return false;
917                 }
918                 payload_bytes.resize(ascii_hex_bytes_cstr_len / 2);
919                 if (extractor.GetHexBytes(payload_bytes, '\xdd') !=
920                     payload_bytes.size()) {
921                   result.AppendErrorWithFormat("payload data must only contain "
922                                                "ASCII hex characters (no "
923                                                "spaces or hex prefixes): '%s'",
924                                                ascii_hex_bytes_cstr);
925                   return false;
926                 }
927               }
928               Status error;
929               DataExtractor reply;
930               process->GetCommunication().SendRawRequest(
931                   command_byte,
932                   payload_bytes.empty() ? NULL : payload_bytes.data(),
933                   payload_bytes.size(), reply, error);
934 
935               if (error.Success()) {
936                 // Copy the binary bytes into a hex ASCII string for the result
937                 StreamString packet;
938                 packet.PutBytesAsRawHex8(
939                     reply.GetDataStart(), reply.GetByteSize(),
940                     endian::InlHostByteOrder(), endian::InlHostByteOrder());
941                 result.AppendMessage(packet.GetString());
942                 result.SetStatus(eReturnStatusSuccessFinishResult);
943                 return true;
944               } else {
945                 const char *error_cstr = error.AsCString();
946                 if (error_cstr && error_cstr[0])
947                   result.AppendError(error_cstr);
948                 else
949                   result.AppendErrorWithFormat("unknown error 0x%8.8x",
950                                                error.GetError());
951                 return false;
952               }
953             } else {
954               result.AppendErrorWithFormat("process must be stopped in order "
955                                            "to send KDP packets, state is %s",
956                                            StateAsCString(state));
957             }
958           } else {
959             result.AppendError("invalid process");
960           }
961         } else {
962           result.AppendErrorWithFormat("invalid command byte 0x%" PRIx64
963                                        ", valid values are 1 - 255",
964                                        command_byte);
965         }
966       }
967     } else {
968       result.AppendErrorWithFormat("'%s' takes no arguments, only options.",
969                                    m_cmd_name.c_str());
970     }
971     return false;
972   }
973 };
974 
975 class CommandObjectProcessKDPPacket : public CommandObjectMultiword {
976 private:
977 public:
978   CommandObjectProcessKDPPacket(CommandInterpreter &interpreter)
979       : CommandObjectMultiword(interpreter, "process plugin packet",
980                                "Commands that deal with KDP remote packets.",
981                                NULL) {
982     LoadSubCommand(
983         "send",
984         CommandObjectSP(new CommandObjectProcessKDPPacketSend(interpreter)));
985   }
986 
987   ~CommandObjectProcessKDPPacket() = default;
988 };
989 
990 class CommandObjectMultiwordProcessKDP : public CommandObjectMultiword {
991 public:
992   CommandObjectMultiwordProcessKDP(CommandInterpreter &interpreter)
993       : CommandObjectMultiword(
994             interpreter, "process plugin",
995             "Commands for operating on a ProcessKDP process.",
996             "process plugin <subcommand> [<subcommand-options>]") {
997     LoadSubCommand("packet", CommandObjectSP(new CommandObjectProcessKDPPacket(
998                                  interpreter)));
999   }
1000 
1001   ~CommandObjectMultiwordProcessKDP() = default;
1002 };
1003 
1004 CommandObject *ProcessKDP::GetPluginCommandObject() {
1005   if (!m_command_sp)
1006     m_command_sp = std::make_shared<CommandObjectMultiwordProcessKDP>(
1007         GetTarget().GetDebugger().GetCommandInterpreter());
1008   return m_command_sp.get();
1009 }
1010