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