1 //===-- CommunicationKDP.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 "CommunicationKDP.h"
10 
11 #include <errno.h>
12 #include <limits.h>
13 #include <string.h>
14 
15 
16 #include "lldb/Core/DumpDataExtractor.h"
17 #include "lldb/Host/Host.h"
18 #include "lldb/Target/Process.h"
19 #include "lldb/Utility/DataBufferHeap.h"
20 #include "lldb/Utility/DataExtractor.h"
21 #include "lldb/Utility/FileSpec.h"
22 #include "lldb/Utility/Log.h"
23 #include "lldb/Utility/State.h"
24 #include "lldb/Utility/UUID.h"
25 
26 #include "ProcessKDPLog.h"
27 
28 using namespace lldb;
29 using namespace lldb_private;
30 
31 // CommunicationKDP constructor
32 CommunicationKDP::CommunicationKDP(const char *comm_name)
33     : Communication(comm_name), m_addr_byte_size(4),
34       m_byte_order(eByteOrderLittle), m_packet_timeout(5), m_sequence_mutex(),
35       m_is_running(false), m_session_key(0u), m_request_sequence_id(0u),
36       m_exception_sequence_id(0u), m_kdp_version_version(0u),
37       m_kdp_version_feature(0u), m_kdp_hostinfo_cpu_mask(0u),
38       m_kdp_hostinfo_cpu_type(0u), m_kdp_hostinfo_cpu_subtype(0u) {}
39 
40 // Destructor
41 CommunicationKDP::~CommunicationKDP() {
42   if (IsConnected()) {
43     Disconnect();
44   }
45 }
46 
47 bool CommunicationKDP::SendRequestPacket(
48     const PacketStreamType &request_packet) {
49   std::lock_guard<std::recursive_mutex> guard(m_sequence_mutex);
50   return SendRequestPacketNoLock(request_packet);
51 }
52 
53 void CommunicationKDP::MakeRequestPacketHeader(CommandType request_type,
54                                                PacketStreamType &request_packet,
55                                                uint16_t request_length) {
56   request_packet.Clear();
57   request_packet.PutHex8(request_type |
58                          ePacketTypeRequest);      // Set the request type
59   request_packet.PutHex8(m_request_sequence_id++); // Sequence number
60   request_packet.PutHex16(
61       request_length); // Length of the packet including this header
62   request_packet.PutHex32(m_session_key); // Session key
63 }
64 
65 bool CommunicationKDP::SendRequestAndGetReply(
66     const CommandType command, const PacketStreamType &request_packet,
67     DataExtractor &reply_packet) {
68   if (IsRunning()) {
69     Log *log(ProcessKDPLog::GetLogIfAllCategoriesSet(KDP_LOG_PACKETS));
70     if (log) {
71       PacketStreamType log_strm;
72       DumpPacket(log_strm, request_packet.GetData(), request_packet.GetSize());
73       LLDB_LOGF(log, "error: kdp running, not sending packet: %.*s",
74                 (uint32_t)log_strm.GetSize(), log_strm.GetData());
75     }
76     return false;
77   }
78 
79   std::lock_guard<std::recursive_mutex> guard(m_sequence_mutex);
80   // NOTE: this only works for packets that are in native endian byte order
81   assert(request_packet.GetSize() ==
82          *((const uint16_t *)(request_packet.GetData() + 2)));
83   lldb::offset_t offset = 1;
84   const uint32_t num_retries = 3;
85   for (uint32_t i = 0; i < num_retries; ++i) {
86     if (SendRequestPacketNoLock(request_packet)) {
87       const uint8_t request_sequence_id = (uint8_t)request_packet.GetData()[1];
88       while (true) {
89         if (WaitForPacketWithTimeoutMicroSecondsNoLock(
90                 reply_packet,
91                 std::chrono::microseconds(GetPacketTimeout()).count())) {
92           offset = 0;
93           const uint8_t reply_command = reply_packet.GetU8(&offset);
94           const uint8_t reply_sequence_id = reply_packet.GetU8(&offset);
95           if (request_sequence_id == reply_sequence_id) {
96             // The sequent ID was correct, now verify we got the response we
97             // were looking for
98             if ((reply_command & eCommandTypeMask) == command) {
99               // Success
100               if (command == KDP_RESUMECPUS)
101                 m_is_running.SetValue(true, eBroadcastAlways);
102               return true;
103             } else {
104               // Failed to get the correct response, bail
105               reply_packet.Clear();
106               return false;
107             }
108           } else if (reply_sequence_id > request_sequence_id) {
109             // Sequence ID was greater than the sequence ID of the packet we
110             // sent, something is really wrong...
111             reply_packet.Clear();
112             return false;
113           } else {
114             // The reply sequence ID was less than our current packet's
115             // sequence ID so we should keep trying to get a response because
116             // this was a response for a previous packet that we must have
117             // retried.
118           }
119         } else {
120           // Break and retry sending the packet as we didn't get a response due
121           // to timeout
122           break;
123         }
124       }
125     }
126   }
127   reply_packet.Clear();
128   return false;
129 }
130 
131 bool CommunicationKDP::SendRequestPacketNoLock(
132     const PacketStreamType &request_packet) {
133   if (IsConnected()) {
134     const char *packet_data = request_packet.GetData();
135     const size_t packet_size = request_packet.GetSize();
136 
137     Log *log(ProcessKDPLog::GetLogIfAllCategoriesSet(KDP_LOG_PACKETS));
138     if (log) {
139       PacketStreamType log_strm;
140       DumpPacket(log_strm, packet_data, packet_size);
141       LLDB_LOGF(log, "%.*s", (uint32_t)log_strm.GetSize(), log_strm.GetData());
142     }
143     ConnectionStatus status = eConnectionStatusSuccess;
144 
145     size_t bytes_written = Write(packet_data, packet_size, status, NULL);
146 
147     if (bytes_written == packet_size)
148       return true;
149 
150     LLDB_LOGF(log,
151               "error: failed to send packet entire packet %" PRIu64
152               " of %" PRIu64 " bytes sent",
153               (uint64_t)bytes_written, (uint64_t)packet_size);
154   }
155   return false;
156 }
157 
158 bool CommunicationKDP::GetSequenceMutex(
159     std::unique_lock<std::recursive_mutex> &lock) {
160   return (lock = std::unique_lock<std::recursive_mutex>(m_sequence_mutex,
161                                                         std::try_to_lock))
162       .owns_lock();
163 }
164 
165 bool CommunicationKDP::WaitForNotRunningPrivate(
166     const std::chrono::microseconds &timeout) {
167   return m_is_running.WaitForValueEqualTo(false, timeout);
168 }
169 
170 size_t
171 CommunicationKDP::WaitForPacketWithTimeoutMicroSeconds(DataExtractor &packet,
172                                                        uint32_t timeout_usec) {
173   std::lock_guard<std::recursive_mutex> guard(m_sequence_mutex);
174   return WaitForPacketWithTimeoutMicroSecondsNoLock(packet, timeout_usec);
175 }
176 
177 size_t CommunicationKDP::WaitForPacketWithTimeoutMicroSecondsNoLock(
178     DataExtractor &packet, uint32_t timeout_usec) {
179   uint8_t buffer[8192];
180   Status error;
181 
182   Log *log(ProcessKDPLog::GetLogIfAllCategoriesSet(KDP_LOG_PACKETS));
183 
184   // Check for a packet from our cache first without trying any reading...
185   if (CheckForPacket(NULL, 0, packet))
186     return packet.GetByteSize();
187 
188   bool timed_out = false;
189   while (IsConnected() && !timed_out) {
190     lldb::ConnectionStatus status = eConnectionStatusNoConnection;
191     size_t bytes_read = Read(buffer, sizeof(buffer),
192                              timeout_usec == UINT32_MAX
193                                  ? Timeout<std::micro>(llvm::None)
194                                  : std::chrono::microseconds(timeout_usec),
195                              status, &error);
196 
197     LLDB_LOGV(log,
198       "Read (buffer, sizeof(buffer), timeout_usec = 0x{0:x}, "
199                   "status = {1}, error = {2}) => bytes_read = {4}",
200                   timeout_usec,
201                   Communication::ConnectionStatusAsCString(status),
202                   error, bytes_read);
203 
204     if (bytes_read > 0) {
205       if (CheckForPacket(buffer, bytes_read, packet))
206         return packet.GetByteSize();
207     } else {
208       switch (status) {
209       case eConnectionStatusInterrupted:
210       case eConnectionStatusTimedOut:
211         timed_out = true;
212         break;
213       case eConnectionStatusSuccess:
214         // printf ("status = success but error = %s\n",
215         // error.AsCString("<invalid>"));
216         break;
217 
218       case eConnectionStatusEndOfFile:
219       case eConnectionStatusNoConnection:
220       case eConnectionStatusLostConnection:
221       case eConnectionStatusError:
222         Disconnect();
223         break;
224       }
225     }
226   }
227   packet.Clear();
228   return 0;
229 }
230 
231 bool CommunicationKDP::CheckForPacket(const uint8_t *src, size_t src_len,
232                                       DataExtractor &packet) {
233   // Put the packet data into the buffer in a thread safe fashion
234   std::lock_guard<std::recursive_mutex> guard(m_bytes_mutex);
235 
236   Log *log(ProcessKDPLog::GetLogIfAllCategoriesSet(KDP_LOG_PACKETS));
237 
238   if (src && src_len > 0) {
239     if (log && log->GetVerbose()) {
240       PacketStreamType log_strm;
241       DumpHexBytes(&log_strm, src, src_len, UINT32_MAX, LLDB_INVALID_ADDRESS);
242       LLDB_LOGF(log, "CommunicationKDP::%s adding %u bytes: %s", __FUNCTION__,
243                 (uint32_t)src_len, log_strm.GetData());
244     }
245     m_bytes.append((const char *)src, src_len);
246   }
247 
248   // Make sure we at least have enough bytes for a packet header
249   const size_t bytes_available = m_bytes.size();
250   if (bytes_available >= 8) {
251     packet.SetData(&m_bytes[0], bytes_available, m_byte_order);
252     lldb::offset_t offset = 0;
253     uint8_t reply_command = packet.GetU8(&offset);
254     switch (reply_command) {
255     case ePacketTypeRequest | KDP_EXCEPTION:
256     case ePacketTypeRequest | KDP_TERMINATION:
257       // We got an exception request, so be sure to send an ACK
258       {
259         PacketStreamType request_ack_packet(Stream::eBinary, m_addr_byte_size,
260                                             m_byte_order);
261         // Set the reply but and make the ACK packet
262         request_ack_packet.PutHex8(reply_command | ePacketTypeReply);
263         request_ack_packet.PutHex8(packet.GetU8(&offset));
264         request_ack_packet.PutHex16(packet.GetU16(&offset));
265         request_ack_packet.PutHex32(packet.GetU32(&offset));
266         m_is_running.SetValue(false, eBroadcastAlways);
267         // Ack to the exception or termination
268         SendRequestPacketNoLock(request_ack_packet);
269       }
270       // Fall through to case below to get packet contents
271       LLVM_FALLTHROUGH;
272     case ePacketTypeReply | KDP_CONNECT:
273     case ePacketTypeReply | KDP_DISCONNECT:
274     case ePacketTypeReply | KDP_HOSTINFO:
275     case ePacketTypeReply | KDP_VERSION:
276     case ePacketTypeReply | KDP_MAXBYTES:
277     case ePacketTypeReply | KDP_READMEM:
278     case ePacketTypeReply | KDP_WRITEMEM:
279     case ePacketTypeReply | KDP_READREGS:
280     case ePacketTypeReply | KDP_WRITEREGS:
281     case ePacketTypeReply | KDP_LOAD:
282     case ePacketTypeReply | KDP_IMAGEPATH:
283     case ePacketTypeReply | KDP_SUSPEND:
284     case ePacketTypeReply | KDP_RESUMECPUS:
285     case ePacketTypeReply | KDP_BREAKPOINT_SET:
286     case ePacketTypeReply | KDP_BREAKPOINT_REMOVE:
287     case ePacketTypeReply | KDP_REGIONS:
288     case ePacketTypeReply | KDP_REATTACH:
289     case ePacketTypeReply | KDP_HOSTREBOOT:
290     case ePacketTypeReply | KDP_READMEM64:
291     case ePacketTypeReply | KDP_WRITEMEM64:
292     case ePacketTypeReply | KDP_BREAKPOINT_SET64:
293     case ePacketTypeReply | KDP_BREAKPOINT_REMOVE64:
294     case ePacketTypeReply | KDP_KERNELVERSION:
295     case ePacketTypeReply | KDP_READPHYSMEM64:
296     case ePacketTypeReply | KDP_WRITEPHYSMEM64:
297     case ePacketTypeReply | KDP_READIOPORT:
298     case ePacketTypeReply | KDP_WRITEIOPORT:
299     case ePacketTypeReply | KDP_READMSR64:
300     case ePacketTypeReply | KDP_WRITEMSR64:
301     case ePacketTypeReply | KDP_DUMPINFO: {
302       offset = 2;
303       const uint16_t length = packet.GetU16(&offset);
304       if (length <= bytes_available) {
305         // We have an entire packet ready, we need to copy the data bytes into
306         // a buffer that will be owned by the packet and erase the bytes from
307         // our communication buffer "m_bytes"
308         packet.SetData(DataBufferSP(new DataBufferHeap(&m_bytes[0], length)));
309         m_bytes.erase(0, length);
310 
311         if (log) {
312           PacketStreamType log_strm;
313           DumpPacket(log_strm, packet);
314 
315           LLDB_LOGF(log, "%.*s", (uint32_t)log_strm.GetSize(),
316                     log_strm.GetData());
317         }
318         return true;
319       }
320     } break;
321 
322     default:
323       // Unrecognized reply command byte, erase this byte and try to get back
324       // on track
325       LLDB_LOGF(log, "CommunicationKDP::%s: tossing junk byte: 0x%2.2x",
326                 __FUNCTION__, (uint8_t)m_bytes[0]);
327       m_bytes.erase(0, 1);
328       break;
329     }
330   }
331   packet.Clear();
332   return false;
333 }
334 
335 bool CommunicationKDP::SendRequestConnect(uint16_t reply_port,
336                                           uint16_t exc_port,
337                                           const char *greeting) {
338   PacketStreamType request_packet(Stream::eBinary, m_addr_byte_size,
339                                   m_byte_order);
340   if (greeting == NULL)
341     greeting = "";
342 
343   const CommandType command = KDP_CONNECT;
344   // Length is 82 uint16_t and the length of the greeting C string with the
345   // terminating NULL
346   const uint32_t command_length = 8 + 2 + 2 + ::strlen(greeting) + 1;
347   MakeRequestPacketHeader(command, request_packet, command_length);
348   // Always send connect ports as little endian
349   request_packet.SetByteOrder(eByteOrderLittle);
350   request_packet.PutHex16(htons(reply_port));
351   request_packet.PutHex16(htons(exc_port));
352   request_packet.SetByteOrder(m_byte_order);
353   request_packet.PutCString(greeting);
354   DataExtractor reply_packet;
355   return SendRequestAndGetReply(command, request_packet, reply_packet);
356 }
357 
358 void CommunicationKDP::ClearKDPSettings() {
359   m_request_sequence_id = 0;
360   m_kdp_version_version = 0;
361   m_kdp_version_feature = 0;
362   m_kdp_hostinfo_cpu_mask = 0;
363   m_kdp_hostinfo_cpu_type = 0;
364   m_kdp_hostinfo_cpu_subtype = 0;
365 }
366 
367 bool CommunicationKDP::SendRequestReattach(uint16_t reply_port) {
368   PacketStreamType request_packet(Stream::eBinary, m_addr_byte_size,
369                                   m_byte_order);
370   const CommandType command = KDP_REATTACH;
371   // Length is 8 bytes for the header plus 2 bytes for the reply UDP port
372   const uint32_t command_length = 8 + 2;
373   MakeRequestPacketHeader(command, request_packet, command_length);
374   // Always send connect ports as little endian
375   request_packet.SetByteOrder(eByteOrderLittle);
376   request_packet.PutHex16(htons(reply_port));
377   request_packet.SetByteOrder(m_byte_order);
378   DataExtractor reply_packet;
379   if (SendRequestAndGetReply(command, request_packet, reply_packet)) {
380     // Reset the sequence ID to zero for reattach
381     ClearKDPSettings();
382     lldb::offset_t offset = 4;
383     m_session_key = reply_packet.GetU32(&offset);
384     return true;
385   }
386   return false;
387 }
388 
389 uint32_t CommunicationKDP::GetVersion() {
390   if (!VersionIsValid())
391     SendRequestVersion();
392   return m_kdp_version_version;
393 }
394 
395 uint32_t CommunicationKDP::GetFeatureFlags() {
396   if (!VersionIsValid())
397     SendRequestVersion();
398   return m_kdp_version_feature;
399 }
400 
401 bool CommunicationKDP::SendRequestVersion() {
402   PacketStreamType request_packet(Stream::eBinary, m_addr_byte_size,
403                                   m_byte_order);
404   const CommandType command = KDP_VERSION;
405   const uint32_t command_length = 8;
406   MakeRequestPacketHeader(command, request_packet, command_length);
407   DataExtractor reply_packet;
408   if (SendRequestAndGetReply(command, request_packet, reply_packet)) {
409     lldb::offset_t offset = 8;
410     m_kdp_version_version = reply_packet.GetU32(&offset);
411     m_kdp_version_feature = reply_packet.GetU32(&offset);
412     return true;
413   }
414   return false;
415 }
416 
417 uint32_t CommunicationKDP::GetCPUMask() {
418   if (!HostInfoIsValid())
419     SendRequestHostInfo();
420   return m_kdp_hostinfo_cpu_mask;
421 }
422 
423 uint32_t CommunicationKDP::GetCPUType() {
424   if (!HostInfoIsValid())
425     SendRequestHostInfo();
426   return m_kdp_hostinfo_cpu_type;
427 }
428 
429 uint32_t CommunicationKDP::GetCPUSubtype() {
430   if (!HostInfoIsValid())
431     SendRequestHostInfo();
432   return m_kdp_hostinfo_cpu_subtype;
433 }
434 
435 lldb_private::UUID CommunicationKDP::GetUUID() {
436   UUID uuid;
437   if (GetKernelVersion() == NULL)
438     return uuid;
439 
440   if (m_kernel_version.find("UUID=") == std::string::npos)
441     return uuid;
442 
443   size_t p = m_kernel_version.find("UUID=") + strlen("UUID=");
444   std::string uuid_str = m_kernel_version.substr(p, 36);
445   if (uuid_str.size() < 32)
446     return uuid;
447 
448   if (!uuid.SetFromStringRef(uuid_str)) {
449     UUID invalid_uuid;
450     return invalid_uuid;
451   }
452 
453   return uuid;
454 }
455 
456 bool CommunicationKDP::RemoteIsEFI() {
457   if (GetKernelVersion() == NULL)
458     return false;
459   return strncmp(m_kernel_version.c_str(), "EFI", 3) == 0;
460 }
461 
462 bool CommunicationKDP::RemoteIsDarwinKernel() {
463   if (GetKernelVersion() == NULL)
464     return false;
465   return m_kernel_version.find("Darwin Kernel") != std::string::npos;
466 }
467 
468 lldb::addr_t CommunicationKDP::GetLoadAddress() {
469   if (GetKernelVersion() == NULL)
470     return LLDB_INVALID_ADDRESS;
471 
472   if (m_kernel_version.find("stext=") == std::string::npos)
473     return LLDB_INVALID_ADDRESS;
474   size_t p = m_kernel_version.find("stext=") + strlen("stext=");
475   if (m_kernel_version[p] != '0' || m_kernel_version[p + 1] != 'x')
476     return LLDB_INVALID_ADDRESS;
477 
478   addr_t kernel_load_address;
479   errno = 0;
480   kernel_load_address = ::strtoul(m_kernel_version.c_str() + p, NULL, 16);
481   if (errno != 0 || kernel_load_address == 0)
482     return LLDB_INVALID_ADDRESS;
483 
484   return kernel_load_address;
485 }
486 
487 bool CommunicationKDP::SendRequestHostInfo() {
488   PacketStreamType request_packet(Stream::eBinary, m_addr_byte_size,
489                                   m_byte_order);
490   const CommandType command = KDP_HOSTINFO;
491   const uint32_t command_length = 8;
492   MakeRequestPacketHeader(command, request_packet, command_length);
493   DataExtractor reply_packet;
494   if (SendRequestAndGetReply(command, request_packet, reply_packet)) {
495     lldb::offset_t offset = 8;
496     m_kdp_hostinfo_cpu_mask = reply_packet.GetU32(&offset);
497     m_kdp_hostinfo_cpu_type = reply_packet.GetU32(&offset);
498     m_kdp_hostinfo_cpu_subtype = reply_packet.GetU32(&offset);
499 
500     ArchSpec kernel_arch;
501     kernel_arch.SetArchitecture(eArchTypeMachO, m_kdp_hostinfo_cpu_type,
502                                 m_kdp_hostinfo_cpu_subtype);
503 
504     m_addr_byte_size = kernel_arch.GetAddressByteSize();
505     m_byte_order = kernel_arch.GetByteOrder();
506     return true;
507   }
508   return false;
509 }
510 
511 const char *CommunicationKDP::GetKernelVersion() {
512   if (m_kernel_version.empty())
513     SendRequestKernelVersion();
514   return m_kernel_version.c_str();
515 }
516 
517 bool CommunicationKDP::SendRequestKernelVersion() {
518   PacketStreamType request_packet(Stream::eBinary, m_addr_byte_size,
519                                   m_byte_order);
520   const CommandType command = KDP_KERNELVERSION;
521   const uint32_t command_length = 8;
522   MakeRequestPacketHeader(command, request_packet, command_length);
523   DataExtractor reply_packet;
524   if (SendRequestAndGetReply(command, request_packet, reply_packet)) {
525     const char *kernel_version_cstr = reply_packet.PeekCStr(8);
526     if (kernel_version_cstr && kernel_version_cstr[0])
527       m_kernel_version.assign(kernel_version_cstr);
528     return true;
529   }
530   return false;
531 }
532 
533 bool CommunicationKDP::SendRequestDisconnect() {
534   PacketStreamType request_packet(Stream::eBinary, m_addr_byte_size,
535                                   m_byte_order);
536   const CommandType command = KDP_DISCONNECT;
537   const uint32_t command_length = 8;
538   MakeRequestPacketHeader(command, request_packet, command_length);
539   DataExtractor reply_packet;
540   if (SendRequestAndGetReply(command, request_packet, reply_packet)) {
541     // Are we supposed to get a reply for disconnect?
542   }
543   ClearKDPSettings();
544   return true;
545 }
546 
547 uint32_t CommunicationKDP::SendRequestReadMemory(lldb::addr_t addr, void *dst,
548                                                  uint32_t dst_len,
549                                                  Status &error) {
550   PacketStreamType request_packet(Stream::eBinary, m_addr_byte_size,
551                                   m_byte_order);
552   bool use_64 = (GetVersion() >= 11);
553   uint32_t command_addr_byte_size = use_64 ? 8 : 4;
554   const CommandType command = use_64 ? KDP_READMEM64 : KDP_READMEM;
555   // Size is header + address size + uint32_t length
556   const uint32_t command_length = 8 + command_addr_byte_size + 4;
557   MakeRequestPacketHeader(command, request_packet, command_length);
558   request_packet.PutMaxHex64(addr, command_addr_byte_size);
559   request_packet.PutHex32(dst_len);
560   DataExtractor reply_packet;
561   if (SendRequestAndGetReply(command, request_packet, reply_packet)) {
562     lldb::offset_t offset = 8;
563     uint32_t kdp_error = reply_packet.GetU32(&offset);
564     uint32_t src_len = reply_packet.GetByteSize() - 12;
565 
566     if (src_len > 0) {
567       const void *src = reply_packet.GetData(&offset, src_len);
568       if (src) {
569         ::memcpy(dst, src, src_len);
570         error.Clear();
571         return src_len;
572       }
573     }
574     if (kdp_error)
575       error.SetErrorStringWithFormat("kdp read memory failed (error %u)",
576                                      kdp_error);
577     else
578       error.SetErrorString("kdp read memory failed");
579   } else {
580     error.SetErrorString("failed to send packet");
581   }
582   return 0;
583 }
584 
585 uint32_t CommunicationKDP::SendRequestWriteMemory(lldb::addr_t addr,
586                                                   const void *src,
587                                                   uint32_t src_len,
588                                                   Status &error) {
589   PacketStreamType request_packet(Stream::eBinary, m_addr_byte_size,
590                                   m_byte_order);
591   bool use_64 = (GetVersion() >= 11);
592   uint32_t command_addr_byte_size = use_64 ? 8 : 4;
593   const CommandType command = use_64 ? KDP_WRITEMEM64 : KDP_WRITEMEM;
594   // Size is header + address size + uint32_t length
595   const uint32_t command_length = 8 + command_addr_byte_size + 4 + src_len;
596   MakeRequestPacketHeader(command, request_packet, command_length);
597   request_packet.PutMaxHex64(addr, command_addr_byte_size);
598   request_packet.PutHex32(src_len);
599   request_packet.PutRawBytes(src, src_len);
600 
601   DataExtractor reply_packet;
602   if (SendRequestAndGetReply(command, request_packet, reply_packet)) {
603     lldb::offset_t offset = 8;
604     uint32_t kdp_error = reply_packet.GetU32(&offset);
605     if (kdp_error)
606       error.SetErrorStringWithFormat("kdp write memory failed (error %u)",
607                                      kdp_error);
608     else {
609       error.Clear();
610       return src_len;
611     }
612   } else {
613     error.SetErrorString("failed to send packet");
614   }
615   return 0;
616 }
617 
618 bool CommunicationKDP::SendRawRequest(
619     uint8_t command_byte,
620     const void *src,  // Raw packet payload bytes
621     uint32_t src_len, // Raw packet payload length
622     DataExtractor &reply_packet, Status &error) {
623   PacketStreamType request_packet(Stream::eBinary, m_addr_byte_size,
624                                   m_byte_order);
625   // Size is header + address size + uint32_t length
626   const uint32_t command_length = 8 + src_len;
627   const CommandType command = (CommandType)command_byte;
628   MakeRequestPacketHeader(command, request_packet, command_length);
629   request_packet.PutRawBytes(src, src_len);
630 
631   if (SendRequestAndGetReply(command, request_packet, reply_packet)) {
632     lldb::offset_t offset = 8;
633     uint32_t kdp_error = reply_packet.GetU32(&offset);
634     if (kdp_error && (command_byte != KDP_DUMPINFO))
635       error.SetErrorStringWithFormat("request packet 0x%8.8x failed (error %u)",
636                                      command_byte, kdp_error);
637     else {
638       error.Clear();
639       return true;
640     }
641   } else {
642     error.SetErrorString("failed to send packet");
643   }
644   return false;
645 }
646 
647 const char *CommunicationKDP::GetCommandAsCString(uint8_t command) {
648   switch (command) {
649   case KDP_CONNECT:
650     return "KDP_CONNECT";
651   case KDP_DISCONNECT:
652     return "KDP_DISCONNECT";
653   case KDP_HOSTINFO:
654     return "KDP_HOSTINFO";
655   case KDP_VERSION:
656     return "KDP_VERSION";
657   case KDP_MAXBYTES:
658     return "KDP_MAXBYTES";
659   case KDP_READMEM:
660     return "KDP_READMEM";
661   case KDP_WRITEMEM:
662     return "KDP_WRITEMEM";
663   case KDP_READREGS:
664     return "KDP_READREGS";
665   case KDP_WRITEREGS:
666     return "KDP_WRITEREGS";
667   case KDP_LOAD:
668     return "KDP_LOAD";
669   case KDP_IMAGEPATH:
670     return "KDP_IMAGEPATH";
671   case KDP_SUSPEND:
672     return "KDP_SUSPEND";
673   case KDP_RESUMECPUS:
674     return "KDP_RESUMECPUS";
675   case KDP_EXCEPTION:
676     return "KDP_EXCEPTION";
677   case KDP_TERMINATION:
678     return "KDP_TERMINATION";
679   case KDP_BREAKPOINT_SET:
680     return "KDP_BREAKPOINT_SET";
681   case KDP_BREAKPOINT_REMOVE:
682     return "KDP_BREAKPOINT_REMOVE";
683   case KDP_REGIONS:
684     return "KDP_REGIONS";
685   case KDP_REATTACH:
686     return "KDP_REATTACH";
687   case KDP_HOSTREBOOT:
688     return "KDP_HOSTREBOOT";
689   case KDP_READMEM64:
690     return "KDP_READMEM64";
691   case KDP_WRITEMEM64:
692     return "KDP_WRITEMEM64";
693   case KDP_BREAKPOINT_SET64:
694     return "KDP_BREAKPOINT64_SET";
695   case KDP_BREAKPOINT_REMOVE64:
696     return "KDP_BREAKPOINT64_REMOVE";
697   case KDP_KERNELVERSION:
698     return "KDP_KERNELVERSION";
699   case KDP_READPHYSMEM64:
700     return "KDP_READPHYSMEM64";
701   case KDP_WRITEPHYSMEM64:
702     return "KDP_WRITEPHYSMEM64";
703   case KDP_READIOPORT:
704     return "KDP_READIOPORT";
705   case KDP_WRITEIOPORT:
706     return "KDP_WRITEIOPORT";
707   case KDP_READMSR64:
708     return "KDP_READMSR64";
709   case KDP_WRITEMSR64:
710     return "KDP_WRITEMSR64";
711   case KDP_DUMPINFO:
712     return "KDP_DUMPINFO";
713   }
714   return NULL;
715 }
716 
717 void CommunicationKDP::DumpPacket(Stream &s, const void *data,
718                                   uint32_t data_len) {
719   DataExtractor extractor(data, data_len, m_byte_order, m_addr_byte_size);
720   DumpPacket(s, extractor);
721 }
722 
723 void CommunicationKDP::DumpPacket(Stream &s, const DataExtractor &packet) {
724   const char *error_desc = NULL;
725   if (packet.GetByteSize() < 8) {
726     error_desc = "error: invalid packet (too short): ";
727   } else {
728     lldb::offset_t offset = 0;
729     const uint8_t first_packet_byte = packet.GetU8(&offset);
730     const uint8_t sequence_id = packet.GetU8(&offset);
731     const uint16_t length = packet.GetU16(&offset);
732     const uint32_t key = packet.GetU32(&offset);
733     const CommandType command = ExtractCommand(first_packet_byte);
734     const char *command_name = GetCommandAsCString(command);
735     if (command_name) {
736       const bool is_reply = ExtractIsReply(first_packet_byte);
737       s.Printf("(running=%i) %s %24s: 0x%2.2x 0x%2.2x 0x%4.4x 0x%8.8x ",
738                IsRunning(), is_reply ? "<--" : "-->", command_name,
739                first_packet_byte, sequence_id, length, key);
740 
741       if (is_reply) {
742         // Dump request reply packets
743         switch (command) {
744         // Commands that return a single 32 bit error
745         case KDP_CONNECT:
746         case KDP_WRITEMEM:
747         case KDP_WRITEMEM64:
748         case KDP_BREAKPOINT_SET:
749         case KDP_BREAKPOINT_REMOVE:
750         case KDP_BREAKPOINT_SET64:
751         case KDP_BREAKPOINT_REMOVE64:
752         case KDP_WRITEREGS:
753         case KDP_LOAD:
754         case KDP_WRITEIOPORT:
755         case KDP_WRITEMSR64: {
756           const uint32_t error = packet.GetU32(&offset);
757           s.Printf(" (error=0x%8.8x)", error);
758         } break;
759 
760         case KDP_DISCONNECT:
761         case KDP_REATTACH:
762         case KDP_HOSTREBOOT:
763         case KDP_SUSPEND:
764         case KDP_RESUMECPUS:
765         case KDP_EXCEPTION:
766         case KDP_TERMINATION:
767           // No return value for the reply, just the header to ack
768           s.PutCString(" ()");
769           break;
770 
771         case KDP_HOSTINFO: {
772           const uint32_t cpu_mask = packet.GetU32(&offset);
773           const uint32_t cpu_type = packet.GetU32(&offset);
774           const uint32_t cpu_subtype = packet.GetU32(&offset);
775           s.Printf(" (cpu_mask=0x%8.8x, cpu_type=0x%8.8x, cpu_subtype=0x%8.8x)",
776                    cpu_mask, cpu_type, cpu_subtype);
777         } break;
778 
779         case KDP_VERSION: {
780           const uint32_t version = packet.GetU32(&offset);
781           const uint32_t feature = packet.GetU32(&offset);
782           s.Printf(" (version=0x%8.8x, feature=0x%8.8x)", version, feature);
783         } break;
784 
785         case KDP_REGIONS: {
786           const uint32_t region_count = packet.GetU32(&offset);
787           s.Printf(" (count = %u", region_count);
788           for (uint32_t i = 0; i < region_count; ++i) {
789             const addr_t region_addr = packet.GetAddress(&offset);
790             const uint32_t region_size = packet.GetU32(&offset);
791             const uint32_t region_prot = packet.GetU32(&offset);
792             s.Printf("\n\tregion[%" PRIu64 "] = { range = [0x%16.16" PRIx64
793                      " - 0x%16.16" PRIx64 "), size = 0x%8.8x, prot = %s }",
794                      region_addr, region_addr, region_addr + region_size,
795                      region_size, GetPermissionsAsCString(region_prot));
796           }
797         } break;
798 
799         case KDP_READMEM:
800         case KDP_READMEM64:
801         case KDP_READPHYSMEM64: {
802           const uint32_t error = packet.GetU32(&offset);
803           const uint32_t count = packet.GetByteSize() - offset;
804           s.Printf(" (error = 0x%8.8x:\n", error);
805           if (count > 0)
806             DumpDataExtractor(packet,
807                               &s,                      // Stream to dump to
808                               offset,                  // Offset within "packet"
809                               eFormatBytesWithASCII,   // Format to use
810                               1,                       // Size of each item
811                                                        // in bytes
812                               count,                   // Number of items
813                               16,                      // Number per line
814                               m_last_read_memory_addr, // Don't show addresses
815                                                        // before each line
816                               0, 0);                   // No bitfields
817         } break;
818 
819         case KDP_READREGS: {
820           const uint32_t error = packet.GetU32(&offset);
821           const uint32_t count = packet.GetByteSize() - offset;
822           s.Printf(" (error = 0x%8.8x regs:\n", error);
823           if (count > 0)
824             DumpDataExtractor(packet,
825                               &s,                       // Stream to dump to
826                               offset,                   // Offset within "packet"
827                               eFormatHex,               // Format to use
828                               m_addr_byte_size,         // Size of each item
829                                                         // in bytes
830                               count / m_addr_byte_size, // Number of items
831                               16 / m_addr_byte_size,    // Number per line
832                               LLDB_INVALID_ADDRESS,
833                                                         // Don't
834                                                         // show addresses before
835                                                         // each line
836                               0, 0);                    // No bitfields
837         } break;
838 
839         case KDP_KERNELVERSION: {
840           const char *kernel_version = packet.PeekCStr(8);
841           s.Printf(" (version = \"%s\")", kernel_version);
842         } break;
843 
844         case KDP_MAXBYTES: {
845           const uint32_t max_bytes = packet.GetU32(&offset);
846           s.Printf(" (max_bytes = 0x%8.8x (%u))", max_bytes, max_bytes);
847         } break;
848         case KDP_IMAGEPATH: {
849           const char *path = packet.GetCStr(&offset);
850           s.Printf(" (path = \"%s\")", path);
851         } break;
852 
853         case KDP_READIOPORT:
854         case KDP_READMSR64: {
855           const uint32_t error = packet.GetU32(&offset);
856           const uint32_t count = packet.GetByteSize() - offset;
857           s.Printf(" (error = 0x%8.8x io:\n", error);
858           if (count > 0)
859             DumpDataExtractor(packet,
860                               &s,                   // Stream to dump to
861                               offset,               // Offset within "packet"
862                               eFormatHex,           // Format to use
863                               1,                    // Size of each item in bytes
864                               count,                // Number of items
865                               16,                   // Number per line
866                               LLDB_INVALID_ADDRESS, // Don't show addresses
867                                                     // before each line
868                               0, 0);                // No bitfields
869         } break;
870         case KDP_DUMPINFO: {
871           const uint32_t count = packet.GetByteSize() - offset;
872           s.Printf(" (count = %u, bytes = \n", count);
873           if (count > 0)
874             DumpDataExtractor(packet,
875                               &s,                   // Stream to dump to
876                               offset,               // Offset within "packet"
877                               eFormatHex,           // Format to use
878                               1,                    // Size of each item in
879                                                     // bytes
880                               count,                // Number of items
881                               16,                   // Number per line
882                               LLDB_INVALID_ADDRESS, // Don't show addresses
883                                                     // before each line
884                               0, 0);                // No bitfields
885 
886         } break;
887 
888         default:
889           s.Printf(" (add support for dumping this packet reply!!!");
890           break;
891         }
892       } else {
893         // Dump request packets
894         switch (command) {
895         case KDP_CONNECT: {
896           const uint16_t reply_port = ntohs(packet.GetU16(&offset));
897           const uint16_t exc_port = ntohs(packet.GetU16(&offset));
898           s.Printf(" (reply_port = %u, exc_port = %u, greeting = \"%s\")",
899                    reply_port, exc_port, packet.GetCStr(&offset));
900         } break;
901 
902         case KDP_DISCONNECT:
903         case KDP_HOSTREBOOT:
904         case KDP_HOSTINFO:
905         case KDP_VERSION:
906         case KDP_REGIONS:
907         case KDP_KERNELVERSION:
908         case KDP_MAXBYTES:
909         case KDP_IMAGEPATH:
910         case KDP_SUSPEND:
911           // No args, just the header in the request...
912           s.PutCString(" ()");
913           break;
914 
915         case KDP_RESUMECPUS: {
916           const uint32_t cpu_mask = packet.GetU32(&offset);
917           s.Printf(" (cpu_mask = 0x%8.8x)", cpu_mask);
918         } break;
919 
920         case KDP_READMEM: {
921           const uint32_t addr = packet.GetU32(&offset);
922           const uint32_t size = packet.GetU32(&offset);
923           s.Printf(" (addr = 0x%8.8x, size = %u)", addr, size);
924           m_last_read_memory_addr = addr;
925         } break;
926 
927         case KDP_WRITEMEM: {
928           const uint32_t addr = packet.GetU32(&offset);
929           const uint32_t size = packet.GetU32(&offset);
930           s.Printf(" (addr = 0x%8.8x, size = %u, bytes = \n", addr, size);
931           if (size > 0)
932             DumpHexBytes(&s, packet.GetData(&offset, size), size, 32, addr);
933         } break;
934 
935         case KDP_READMEM64: {
936           const uint64_t addr = packet.GetU64(&offset);
937           const uint32_t size = packet.GetU32(&offset);
938           s.Printf(" (addr = 0x%16.16" PRIx64 ", size = %u)", addr, size);
939           m_last_read_memory_addr = addr;
940         } break;
941 
942         case KDP_READPHYSMEM64: {
943           const uint64_t addr = packet.GetU64(&offset);
944           const uint32_t size = packet.GetU32(&offset);
945           const uint32_t lcpu = packet.GetU16(&offset);
946           s.Printf(" (addr = 0x%16.16llx, size = %u, lcpu = %u)", addr, size,
947                    lcpu);
948           m_last_read_memory_addr = addr;
949         } break;
950 
951         case KDP_WRITEMEM64: {
952           const uint64_t addr = packet.GetU64(&offset);
953           const uint32_t size = packet.GetU32(&offset);
954           s.Printf(" (addr = 0x%16.16" PRIx64 ", size = %u, bytes = \n", addr,
955                    size);
956           if (size > 0)
957             DumpHexBytes(&s, packet.GetData(&offset, size), size, 32, addr);
958         } break;
959 
960         case KDP_WRITEPHYSMEM64: {
961           const uint64_t addr = packet.GetU64(&offset);
962           const uint32_t size = packet.GetU32(&offset);
963           const uint32_t lcpu = packet.GetU16(&offset);
964           s.Printf(" (addr = 0x%16.16llx, size = %u, lcpu = %u, bytes = \n",
965                    addr, size, lcpu);
966           if (size > 0)
967             DumpHexBytes(&s, packet.GetData(&offset, size), size, 32, addr);
968         } break;
969 
970         case KDP_READREGS: {
971           const uint32_t cpu = packet.GetU32(&offset);
972           const uint32_t flavor = packet.GetU32(&offset);
973           s.Printf(" (cpu = %u, flavor = %u)", cpu, flavor);
974         } break;
975 
976         case KDP_WRITEREGS: {
977           const uint32_t cpu = packet.GetU32(&offset);
978           const uint32_t flavor = packet.GetU32(&offset);
979           const uint32_t nbytes = packet.GetByteSize() - offset;
980           s.Printf(" (cpu = %u, flavor = %u, regs = \n", cpu, flavor);
981           if (nbytes > 0)
982             DumpDataExtractor(packet,
983                               &s,                        // Stream to dump to
984                               offset,                    // Offset within
985                                                          // "packet"
986                               eFormatHex,                // Format to use
987                               m_addr_byte_size,          // Size of each item in
988                                                          // bytes
989                               nbytes / m_addr_byte_size, // Number of items
990                               16 / m_addr_byte_size,     // Number per line
991                               LLDB_INVALID_ADDRESS,      // Don't show addresses
992                                                          // before each line
993                               0, 0);                // No bitfields
994         } break;
995 
996         case KDP_BREAKPOINT_SET:
997         case KDP_BREAKPOINT_REMOVE: {
998           const uint32_t addr = packet.GetU32(&offset);
999           s.Printf(" (addr = 0x%8.8x)", addr);
1000         } break;
1001 
1002         case KDP_BREAKPOINT_SET64:
1003         case KDP_BREAKPOINT_REMOVE64: {
1004           const uint64_t addr = packet.GetU64(&offset);
1005           s.Printf(" (addr = 0x%16.16" PRIx64 ")", addr);
1006         } break;
1007 
1008         case KDP_LOAD: {
1009           const char *path = packet.GetCStr(&offset);
1010           s.Printf(" (path = \"%s\")", path);
1011         } break;
1012 
1013         case KDP_EXCEPTION: {
1014           const uint32_t count = packet.GetU32(&offset);
1015 
1016           for (uint32_t i = 0; i < count; ++i) {
1017             const uint32_t cpu = packet.GetU32(&offset);
1018             const uint32_t exc = packet.GetU32(&offset);
1019             const uint32_t code = packet.GetU32(&offset);
1020             const uint32_t subcode = packet.GetU32(&offset);
1021             const char *exc_cstr = NULL;
1022             switch (exc) {
1023             case 1:
1024               exc_cstr = "EXC_BAD_ACCESS";
1025               break;
1026             case 2:
1027               exc_cstr = "EXC_BAD_INSTRUCTION";
1028               break;
1029             case 3:
1030               exc_cstr = "EXC_ARITHMETIC";
1031               break;
1032             case 4:
1033               exc_cstr = "EXC_EMULATION";
1034               break;
1035             case 5:
1036               exc_cstr = "EXC_SOFTWARE";
1037               break;
1038             case 6:
1039               exc_cstr = "EXC_BREAKPOINT";
1040               break;
1041             case 7:
1042               exc_cstr = "EXC_SYSCALL";
1043               break;
1044             case 8:
1045               exc_cstr = "EXC_MACH_SYSCALL";
1046               break;
1047             case 9:
1048               exc_cstr = "EXC_RPC_ALERT";
1049               break;
1050             case 10:
1051               exc_cstr = "EXC_CRASH";
1052               break;
1053             default:
1054               break;
1055             }
1056 
1057             s.Printf("{ cpu = 0x%8.8x, exc = %s (%u), code = %u (0x%8.8x), "
1058                      "subcode = %u (0x%8.8x)} ",
1059                      cpu, exc_cstr, exc, code, code, subcode, subcode);
1060           }
1061         } break;
1062 
1063         case KDP_TERMINATION: {
1064           const uint32_t term_code = packet.GetU32(&offset);
1065           const uint32_t exit_code = packet.GetU32(&offset);
1066           s.Printf(" (term_code = 0x%8.8x (%u), exit_code = 0x%8.8x (%u))",
1067                    term_code, term_code, exit_code, exit_code);
1068         } break;
1069 
1070         case KDP_REATTACH: {
1071           const uint16_t reply_port = ntohs(packet.GetU16(&offset));
1072           s.Printf(" (reply_port = %u)", reply_port);
1073         } break;
1074 
1075         case KDP_READMSR64: {
1076           const uint32_t address = packet.GetU32(&offset);
1077           const uint16_t lcpu = packet.GetU16(&offset);
1078           s.Printf(" (address=0x%8.8x, lcpu=0x%4.4x)", address, lcpu);
1079         } break;
1080 
1081         case KDP_WRITEMSR64: {
1082           const uint32_t address = packet.GetU32(&offset);
1083           const uint16_t lcpu = packet.GetU16(&offset);
1084           const uint32_t nbytes = packet.GetByteSize() - offset;
1085           s.Printf(" (address=0x%8.8x, lcpu=0x%4.4x, nbytes=0x%8.8x)", lcpu,
1086                    address, nbytes);
1087           if (nbytes > 0)
1088             DumpDataExtractor(packet,
1089                               &s,                   // Stream to dump to
1090                               offset,               // Offset within "packet"
1091                               eFormatHex,           // Format to use
1092                               1,                    // Size of each item in
1093                                                     // bytes
1094                               nbytes,               // Number of items
1095                               16,                   // Number per line
1096                               LLDB_INVALID_ADDRESS, // Don't show addresses
1097                                                     // before each line
1098                               0, 0);                // No bitfields
1099         } break;
1100 
1101         case KDP_READIOPORT: {
1102           const uint16_t lcpu = packet.GetU16(&offset);
1103           const uint16_t address = packet.GetU16(&offset);
1104           const uint16_t nbytes = packet.GetU16(&offset);
1105           s.Printf(" (lcpu=0x%4.4x, address=0x%4.4x, nbytes=%u)", lcpu, address,
1106                    nbytes);
1107         } break;
1108 
1109         case KDP_WRITEIOPORT: {
1110           const uint16_t lcpu = packet.GetU16(&offset);
1111           const uint16_t address = packet.GetU16(&offset);
1112           const uint16_t nbytes = packet.GetU16(&offset);
1113           s.Printf(" (lcpu = %u, addr = 0x%4.4x, nbytes = %u, bytes = \n", lcpu,
1114                    address, nbytes);
1115           if (nbytes > 0)
1116             DumpDataExtractor(packet,
1117                               &s,                   // Stream to dump to
1118                               offset,               // Offset within "packet"
1119                               eFormatHex,           // Format to use
1120                               1,                    // Size of each item in
1121                                                     // bytes
1122                               nbytes,               // Number of items
1123                               16,                   // Number per line
1124                               LLDB_INVALID_ADDRESS, // Don't show addresses
1125                                                     // before each line
1126                               0, 0);                // No bitfields
1127         } break;
1128 
1129         case KDP_DUMPINFO: {
1130           const uint32_t count = packet.GetByteSize() - offset;
1131           s.Printf(" (count = %u, bytes = \n", count);
1132           if (count > 0)
1133             DumpDataExtractor(packet,
1134                 &s,                   // Stream to dump to
1135                 offset,               // Offset within "packet"
1136                 eFormatHex,           // Format to use
1137                 1,                    // Size of each item in bytes
1138                 count,                // Number of items
1139                 16,                   // Number per line
1140                 LLDB_INVALID_ADDRESS, // Don't show addresses before each line
1141                 0, 0);                // No bitfields
1142 
1143         } break;
1144         }
1145       }
1146     } else {
1147       error_desc = "error: invalid packet command: ";
1148     }
1149   }
1150 
1151   if (error_desc) {
1152     s.PutCString(error_desc);
1153 
1154     DumpDataExtractor(packet,
1155                       &s,                   // Stream to dump to
1156                       0,                    // Offset into "packet"
1157                       eFormatBytes,         // Dump as hex bytes
1158                       1,                    // Size of each item is 1 for
1159                                             // single bytes
1160                       packet.GetByteSize(), // Number of bytes
1161                       UINT32_MAX,           // Num bytes per line
1162                       LLDB_INVALID_ADDRESS, // Base address
1163                       0, 0);                // Bitfield info set to not do
1164                                             // anything bitfield related
1165   }
1166 }
1167 
1168 uint32_t CommunicationKDP::SendRequestReadRegisters(uint32_t cpu,
1169                                                     uint32_t flavor, void *dst,
1170                                                     uint32_t dst_len,
1171                                                     Status &error) {
1172   PacketStreamType request_packet(Stream::eBinary, m_addr_byte_size,
1173                                   m_byte_order);
1174   const CommandType command = KDP_READREGS;
1175   // Size is header + 4 byte cpu and 4 byte flavor
1176   const uint32_t command_length = 8 + 4 + 4;
1177   MakeRequestPacketHeader(command, request_packet, command_length);
1178   request_packet.PutHex32(cpu);
1179   request_packet.PutHex32(flavor);
1180   DataExtractor reply_packet;
1181   if (SendRequestAndGetReply(command, request_packet, reply_packet)) {
1182     lldb::offset_t offset = 8;
1183     uint32_t kdp_error = reply_packet.GetU32(&offset);
1184     uint32_t src_len = reply_packet.GetByteSize() - 12;
1185 
1186     if (src_len > 0) {
1187       const uint32_t bytes_to_copy = std::min<uint32_t>(src_len, dst_len);
1188       const void *src = reply_packet.GetData(&offset, bytes_to_copy);
1189       if (src) {
1190         ::memcpy(dst, src, bytes_to_copy);
1191         error.Clear();
1192         // Return the number of bytes we could have returned regardless if we
1193         // copied them or not, just so we know when things don't match up
1194         return src_len;
1195       }
1196     }
1197     if (kdp_error)
1198       error.SetErrorStringWithFormat(
1199           "failed to read kdp registers for cpu %u flavor %u (error %u)", cpu,
1200           flavor, kdp_error);
1201     else
1202       error.SetErrorStringWithFormat(
1203           "failed to read kdp registers for cpu %u flavor %u", cpu, flavor);
1204   } else {
1205     error.SetErrorString("failed to send packet");
1206   }
1207   return 0;
1208 }
1209 
1210 uint32_t CommunicationKDP::SendRequestWriteRegisters(uint32_t cpu,
1211                                                      uint32_t flavor,
1212                                                      const void *src,
1213                                                      uint32_t src_len,
1214                                                      Status &error) {
1215   PacketStreamType request_packet(Stream::eBinary, m_addr_byte_size,
1216                                   m_byte_order);
1217   const CommandType command = KDP_WRITEREGS;
1218   // Size is header + 4 byte cpu and 4 byte flavor
1219   const uint32_t command_length = 8 + 4 + 4 + src_len;
1220   MakeRequestPacketHeader(command, request_packet, command_length);
1221   request_packet.PutHex32(cpu);
1222   request_packet.PutHex32(flavor);
1223   request_packet.Write(src, src_len);
1224   DataExtractor reply_packet;
1225   if (SendRequestAndGetReply(command, request_packet, reply_packet)) {
1226     lldb::offset_t offset = 8;
1227     uint32_t kdp_error = reply_packet.GetU32(&offset);
1228     if (kdp_error == 0)
1229       return src_len;
1230     error.SetErrorStringWithFormat(
1231         "failed to read kdp registers for cpu %u flavor %u (error %u)", cpu,
1232         flavor, kdp_error);
1233   } else {
1234     error.SetErrorString("failed to send packet");
1235   }
1236   return 0;
1237 }
1238 
1239 bool CommunicationKDP::SendRequestResume() {
1240   PacketStreamType request_packet(Stream::eBinary, m_addr_byte_size,
1241                                   m_byte_order);
1242   const CommandType command = KDP_RESUMECPUS;
1243   const uint32_t command_length = 12;
1244   MakeRequestPacketHeader(command, request_packet, command_length);
1245   request_packet.PutHex32(GetCPUMask());
1246 
1247   DataExtractor reply_packet;
1248   return SendRequestAndGetReply(command, request_packet, reply_packet);
1249 }
1250 
1251 bool CommunicationKDP::SendRequestBreakpoint(bool set, addr_t addr) {
1252   PacketStreamType request_packet(Stream::eBinary, m_addr_byte_size,
1253                                   m_byte_order);
1254   bool use_64 = (GetVersion() >= 11);
1255   uint32_t command_addr_byte_size = use_64 ? 8 : 4;
1256   const CommandType command =
1257       set ? (use_64 ? KDP_BREAKPOINT_SET64 : KDP_BREAKPOINT_SET)
1258           : (use_64 ? KDP_BREAKPOINT_REMOVE64 : KDP_BREAKPOINT_REMOVE);
1259 
1260   const uint32_t command_length = 8 + command_addr_byte_size;
1261   MakeRequestPacketHeader(command, request_packet, command_length);
1262   request_packet.PutMaxHex64(addr, command_addr_byte_size);
1263 
1264   DataExtractor reply_packet;
1265   if (SendRequestAndGetReply(command, request_packet, reply_packet)) {
1266     lldb::offset_t offset = 8;
1267     uint32_t kdp_error = reply_packet.GetU32(&offset);
1268     if (kdp_error == 0)
1269       return true;
1270   }
1271   return false;
1272 }
1273 
1274 bool CommunicationKDP::SendRequestSuspend() {
1275   PacketStreamType request_packet(Stream::eBinary, m_addr_byte_size,
1276                                   m_byte_order);
1277   const CommandType command = KDP_SUSPEND;
1278   const uint32_t command_length = 8;
1279   MakeRequestPacketHeader(command, request_packet, command_length);
1280   DataExtractor reply_packet;
1281   return SendRequestAndGetReply(command, request_packet, reply_packet);
1282 }
1283