1//===-- GDBRemoteRegisterContext.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 "GDBRemoteRegisterContext.h"
10
11#include "ProcessGDBRemote.h"
12#include "ProcessGDBRemoteLog.h"
13#include "ThreadGDBRemote.h"
14#include "Utility/ARM_DWARF_Registers.h"
15#include "Utility/ARM_ehframe_Registers.h"
16#include "lldb/Core/Architecture.h"
17#include "lldb/Target/ExecutionContext.h"
18#include "lldb/Target/Target.h"
19#include "lldb/Utility/DataBufferHeap.h"
20#include "lldb/Utility/DataExtractor.h"
21#include "lldb/Utility/RegisterValue.h"
22#include "lldb/Utility/Scalar.h"
23#include "lldb/Utility/StreamString.h"
24#include "lldb/Utility/StringExtractorGDBRemote.h"
25
26#include <memory>
27
28using namespace lldb;
29using namespace lldb_private;
30using namespace lldb_private::process_gdb_remote;
31
32// GDBRemoteRegisterContext constructor
33GDBRemoteRegisterContext::GDBRemoteRegisterContext(
34 ThreadGDBRemote &thread, uint32_t concrete_frame_idx,
35 GDBRemoteDynamicRegisterInfoSP reg_info_sp, bool read_all_at_once,
36 bool write_all_at_once)
37 : RegisterContext(thread, concrete_frame_idx),
38 m_reg_info_sp(std::move(reg_info_sp)), m_reg_valid(), m_reg_data(),
39 m_read_all_at_once(read_all_at_once),
40 m_write_all_at_once(write_all_at_once), m_gpacket_cached(false) {
41 // Resize our vector of bools to contain one bool for every register. We will
42 // use these boolean values to know when a register value is valid in
43 // m_reg_data.
44 m_reg_valid.resize(new_size: m_reg_info_sp->GetNumRegisters());
45
46 // Make a heap based buffer that is big enough to store all registers
47 DataBufferSP reg_data_sp(
48 new DataBufferHeap(m_reg_info_sp->GetRegisterDataByteSize(), 0));
49 m_reg_data.SetData(data_sp: reg_data_sp);
50 m_reg_data.SetByteOrder(thread.GetProcess()->GetByteOrder());
51}
52
53// Destructor
54GDBRemoteRegisterContext::~GDBRemoteRegisterContext() = default;
55
56void GDBRemoteRegisterContext::InvalidateAllRegisters() {
57 SetAllRegisterValid(false);
58}
59
60void GDBRemoteRegisterContext::SetAllRegisterValid(bool b) {
61 m_gpacket_cached = b;
62 std::vector<bool>::iterator pos, end = m_reg_valid.end();
63 for (pos = m_reg_valid.begin(); pos != end; ++pos)
64 *pos = b;
65}
66
67size_t GDBRemoteRegisterContext::GetRegisterCount() {
68 return m_reg_info_sp->GetNumRegisters();
69}
70
71const RegisterInfo *
72GDBRemoteRegisterContext::GetRegisterInfoAtIndex(size_t reg) {
73 return m_reg_info_sp->GetRegisterInfoAtIndex(i: reg);
74}
75
76size_t GDBRemoteRegisterContext::GetRegisterSetCount() {
77 return m_reg_info_sp->GetNumRegisterSets();
78}
79
80const RegisterSet *GDBRemoteRegisterContext::GetRegisterSet(size_t reg_set) {
81 return m_reg_info_sp->GetRegisterSet(i: reg_set);
82}
83
84bool GDBRemoteRegisterContext::ReadRegister(const RegisterInfo *reg_info,
85 RegisterValue &value) {
86 // Read the register
87 if (ReadRegisterBytes(reg_info)) {
88 const uint32_t reg = reg_info->kinds[eRegisterKindLLDB];
89 if (m_reg_valid[reg] == false)
90 return false;
91 if (reg_info->value_regs &&
92 reg_info->value_regs[0] != LLDB_INVALID_REGNUM &&
93 reg_info->value_regs[1] != LLDB_INVALID_REGNUM) {
94 std::vector<char> combined_data;
95 uint32_t offset = 0;
96 for (int i = 0; reg_info->value_regs[i] != LLDB_INVALID_REGNUM; i++) {
97 const RegisterInfo *parent_reg = GetRegisterInfo(
98 reg_kind: eRegisterKindLLDB, reg_num: reg_info->value_regs[i]);
99 if (!parent_reg)
100 return false;
101 combined_data.resize(new_size: offset + parent_reg->byte_size);
102 if (m_reg_data.CopyData(offset: parent_reg->byte_offset, length: parent_reg->byte_size,
103 dst: combined_data.data() + offset) !=
104 parent_reg->byte_size)
105 return false;
106 offset += parent_reg->byte_size;
107 }
108
109 Status error;
110 return value.SetFromMemoryData(
111 reg_info: *reg_info, src: combined_data.data(), src_len: combined_data.size(),
112 src_byte_order: m_reg_data.GetByteOrder(), error) == combined_data.size();
113 } else {
114 const bool partial_data_ok = false;
115 Status error(value.SetValueFromData(
116 reg_info: *reg_info, data&: m_reg_data, offset: reg_info->byte_offset, partial_data_ok));
117 return error.Success();
118 }
119 }
120 return false;
121}
122
123bool GDBRemoteRegisterContext::PrivateSetRegisterValue(
124 uint32_t reg, llvm::ArrayRef<uint8_t> data) {
125 const RegisterInfo *reg_info = GetRegisterInfoAtIndex(reg);
126 if (reg_info == nullptr)
127 return false;
128
129 // Invalidate if needed
130 InvalidateIfNeeded(force: false);
131
132 const size_t reg_byte_size = reg_info->byte_size;
133 memcpy(dest: const_cast<uint8_t *>(
134 m_reg_data.PeekData(offset: reg_info->byte_offset, length: reg_byte_size)),
135 src: data.data(), n: std::min(a: data.size(), b: reg_byte_size));
136 bool success = data.size() >= reg_byte_size;
137 if (success) {
138 SetRegisterIsValid(reg, valid: true);
139 } else if (data.size() > 0) {
140 // Only set register is valid to false if we copied some bytes, else leave
141 // it as it was.
142 SetRegisterIsValid(reg, valid: false);
143 }
144 return success;
145}
146
147bool GDBRemoteRegisterContext::PrivateSetRegisterValue(uint32_t reg,
148 uint64_t new_reg_val) {
149 const RegisterInfo *reg_info = GetRegisterInfoAtIndex(reg);
150 if (reg_info == nullptr)
151 return false;
152
153 // Early in process startup, we can get a thread that has an invalid byte
154 // order because the process hasn't been completely set up yet (see the ctor
155 // where the byte order is setfrom the process). If that's the case, we
156 // can't set the value here.
157 if (m_reg_data.GetByteOrder() == eByteOrderInvalid) {
158 return false;
159 }
160
161 // Invalidate if needed
162 InvalidateIfNeeded(force: false);
163
164 DataBufferSP buffer_sp(new DataBufferHeap(&new_reg_val, sizeof(new_reg_val)));
165 DataExtractor data(buffer_sp, endian::InlHostByteOrder(), sizeof(void *));
166
167 // If our register context and our register info disagree, which should never
168 // happen, don't overwrite past the end of the buffer.
169 if (m_reg_data.GetByteSize() < reg_info->byte_offset + reg_info->byte_size)
170 return false;
171
172 // Grab a pointer to where we are going to put this register
173 uint8_t *dst = const_cast<uint8_t *>(
174 m_reg_data.PeekData(offset: reg_info->byte_offset, length: reg_info->byte_size));
175
176 if (dst == nullptr)
177 return false;
178
179 if (data.CopyByteOrderedData(src_offset: 0, // src offset
180 src_len: reg_info->byte_size, // src length
181 dst, // dst
182 dst_len: reg_info->byte_size, // dst length
183 dst_byte_order: m_reg_data.GetByteOrder())) // dst byte order
184 {
185 SetRegisterIsValid(reg, valid: true);
186 return true;
187 }
188 return false;
189}
190
191// Helper function for GDBRemoteRegisterContext::ReadRegisterBytes().
192bool GDBRemoteRegisterContext::GetPrimordialRegister(
193 const RegisterInfo *reg_info, GDBRemoteCommunicationClient &gdb_comm) {
194 const uint32_t lldb_reg = reg_info->kinds[eRegisterKindLLDB];
195 const uint32_t remote_reg = reg_info->kinds[eRegisterKindProcessPlugin];
196
197 if (DataBufferSP buffer_sp =
198 gdb_comm.ReadRegister(tid: m_thread.GetProtocolID(), reg_num: remote_reg))
199 return PrivateSetRegisterValue(
200 reg: lldb_reg, data: llvm::ArrayRef<uint8_t>(buffer_sp->GetBytes(),
201 buffer_sp->GetByteSize()));
202 return false;
203}
204
205bool GDBRemoteRegisterContext::ReadRegisterBytes(const RegisterInfo *reg_info) {
206 ExecutionContext exe_ctx(CalculateThread());
207
208 Process *process = exe_ctx.GetProcessPtr();
209 Thread *thread = exe_ctx.GetThreadPtr();
210 if (process == nullptr || thread == nullptr)
211 return false;
212
213 GDBRemoteCommunicationClient &gdb_comm(
214 ((ProcessGDBRemote *)process)->GetGDBRemote());
215
216 InvalidateIfNeeded(force: false);
217
218 const uint32_t reg = reg_info->kinds[eRegisterKindLLDB];
219
220 if (!GetRegisterIsValid(reg)) {
221 if (m_read_all_at_once && !m_gpacket_cached) {
222 if (DataBufferSP buffer_sp =
223 gdb_comm.ReadAllRegisters(tid: m_thread.GetProtocolID())) {
224 memcpy(dest: const_cast<uint8_t *>(m_reg_data.GetDataStart()),
225 src: buffer_sp->GetBytes(),
226 n: std::min(a: buffer_sp->GetByteSize(), b: m_reg_data.GetByteSize()));
227 if (buffer_sp->GetByteSize() >= m_reg_data.GetByteSize()) {
228 SetAllRegisterValid(true);
229 return true;
230 } else if (buffer_sp->GetByteSize() > 0) {
231 for (auto x : llvm::enumerate(
232 First: m_reg_info_sp->registers<
233 DynamicRegisterInfo::reg_collection_const_range>())) {
234 const struct RegisterInfo &reginfo = x.value();
235 m_reg_valid[x.index()] =
236 (reginfo.byte_offset + reginfo.byte_size <=
237 buffer_sp->GetByteSize());
238 }
239
240 m_gpacket_cached = true;
241 if (GetRegisterIsValid(reg))
242 return true;
243 } else {
244 Log *log(GetLog(mask: GDBRLog::Thread | GDBRLog::Packets));
245 LLDB_LOGF(
246 log,
247 "error: GDBRemoteRegisterContext::ReadRegisterBytes tried "
248 "to read the "
249 "entire register context at once, expected at least %" PRId64
250 " bytes "
251 "but only got %" PRId64 " bytes.",
252 m_reg_data.GetByteSize(), buffer_sp->GetByteSize());
253 return false;
254 }
255 }
256 }
257 if (reg_info->value_regs) {
258 // Process this composite register request by delegating to the
259 // constituent primordial registers.
260
261 // Index of the primordial register.
262 bool success = true;
263 for (uint32_t idx = 0; success; ++idx) {
264 const uint32_t prim_reg = reg_info->value_regs[idx];
265 if (prim_reg == LLDB_INVALID_REGNUM)
266 break;
267 // We have a valid primordial register as our constituent. Grab the
268 // corresponding register info.
269 const RegisterInfo *prim_reg_info =
270 GetRegisterInfo(reg_kind: eRegisterKindLLDB, reg_num: prim_reg);
271 if (prim_reg_info == nullptr)
272 success = false;
273 else {
274 // Read the containing register if it hasn't already been read
275 if (!GetRegisterIsValid(reg: prim_reg))
276 success = GetPrimordialRegister(reg_info: prim_reg_info, gdb_comm);
277 }
278 }
279
280 if (success) {
281 // If we reach this point, all primordial register requests have
282 // succeeded. Validate this composite register.
283 SetRegisterIsValid(reg_info, valid: true);
284 }
285 } else {
286 // Get each register individually
287 GetPrimordialRegister(reg_info, gdb_comm);
288 }
289
290 // Make sure we got a valid register value after reading it
291 if (!GetRegisterIsValid(reg))
292 return false;
293 }
294
295 return true;
296}
297
298bool GDBRemoteRegisterContext::WriteRegister(const RegisterInfo *reg_info,
299 const RegisterValue &value) {
300 DataExtractor data;
301 if (value.GetData(data)) {
302 if (reg_info->value_regs &&
303 reg_info->value_regs[0] != LLDB_INVALID_REGNUM &&
304 reg_info->value_regs[1] != LLDB_INVALID_REGNUM) {
305 uint32_t combined_size = 0;
306 for (int i = 0; reg_info->value_regs[i] != LLDB_INVALID_REGNUM; i++) {
307 const RegisterInfo *parent_reg = GetRegisterInfo(
308 reg_kind: eRegisterKindLLDB, reg_num: reg_info->value_regs[i]);
309 if (!parent_reg)
310 return false;
311 combined_size += parent_reg->byte_size;
312 }
313
314 if (data.GetByteSize() < combined_size)
315 return false;
316
317 uint32_t offset = 0;
318 for (int i = 0; reg_info->value_regs[i] != LLDB_INVALID_REGNUM; i++) {
319 const RegisterInfo *parent_reg = GetRegisterInfo(
320 reg_kind: eRegisterKindLLDB, reg_num: reg_info->value_regs[i]);
321 assert(parent_reg);
322
323 DataExtractor parent_data{data, offset, parent_reg->byte_size};
324 if (!WriteRegisterBytes(reg_info: parent_reg, data&: parent_data, data_offset: 0))
325 return false;
326 offset += parent_reg->byte_size;
327 }
328 assert(offset == combined_size);
329 return true;
330 } else
331 return WriteRegisterBytes(reg_info, data, data_offset: 0);
332 }
333 return false;
334}
335
336// Helper function for GDBRemoteRegisterContext::WriteRegisterBytes().
337bool GDBRemoteRegisterContext::SetPrimordialRegister(
338 const RegisterInfo *reg_info, GDBRemoteCommunicationClient &gdb_comm) {
339 StreamString packet;
340 StringExtractorGDBRemote response;
341 const uint32_t reg = reg_info->kinds[eRegisterKindLLDB];
342 // Invalidate just this register
343 SetRegisterIsValid(reg, valid: false);
344
345 return gdb_comm.WriteRegister(
346 tid: m_thread.GetProtocolID(), reg_num: reg_info->kinds[eRegisterKindProcessPlugin],
347 data: {m_reg_data.PeekData(offset: reg_info->byte_offset, length: reg_info->byte_size),
348 reg_info->byte_size});
349}
350
351bool GDBRemoteRegisterContext::WriteRegisterBytes(const RegisterInfo *reg_info,
352 DataExtractor &data,
353 uint32_t data_offset) {
354 ExecutionContext exe_ctx(CalculateThread());
355
356 Process *process = exe_ctx.GetProcessPtr();
357 Thread *thread = exe_ctx.GetThreadPtr();
358 if (process == nullptr || thread == nullptr)
359 return false;
360
361 GDBRemoteCommunicationClient &gdb_comm(
362 ((ProcessGDBRemote *)process)->GetGDBRemote());
363
364 assert(m_reg_data.GetByteSize() >=
365 reg_info->byte_offset + reg_info->byte_size);
366
367 // If our register context and our register info disagree, which should never
368 // happen, don't overwrite past the end of the buffer.
369 if (m_reg_data.GetByteSize() < reg_info->byte_offset + reg_info->byte_size)
370 return false;
371
372 // Grab a pointer to where we are going to put this register
373 uint8_t *dst = const_cast<uint8_t *>(
374 m_reg_data.PeekData(offset: reg_info->byte_offset, length: reg_info->byte_size));
375
376 if (dst == nullptr)
377 return false;
378
379 const bool should_reconfigure_registers =
380 RegisterWriteCausesReconfigure(name: reg_info->name);
381
382 if (data.CopyByteOrderedData(src_offset: data_offset, // src offset
383 src_len: reg_info->byte_size, // src length
384 dst, // dst
385 dst_len: reg_info->byte_size, // dst length
386 dst_byte_order: m_reg_data.GetByteOrder())) // dst byte order
387 {
388 GDBRemoteClientBase::Lock lock(gdb_comm);
389 if (lock) {
390 if (m_write_all_at_once) {
391 // Invalidate all register values
392 InvalidateIfNeeded(force: true);
393
394 // Set all registers in one packet
395 if (gdb_comm.WriteAllRegisters(
396 tid: m_thread.GetProtocolID(),
397 data: {m_reg_data.GetDataStart(), size_t(m_reg_data.GetByteSize())}))
398
399 {
400 if (should_reconfigure_registers)
401 ReconfigureRegisterInfo();
402
403 InvalidateAllRegisters();
404
405 return true;
406 }
407 } else {
408 bool success = true;
409
410 if (reg_info->value_regs) {
411 // This register is part of another register. In this case we read
412 // the actual register data for any "value_regs", and once all that
413 // data is read, we will have enough data in our register context
414 // bytes for the value of this register
415
416 // Invalidate this composite register first.
417
418 for (uint32_t idx = 0; success; ++idx) {
419 const uint32_t reg = reg_info->value_regs[idx];
420 if (reg == LLDB_INVALID_REGNUM)
421 break;
422 // We have a valid primordial register as our constituent. Grab the
423 // corresponding register info.
424 const RegisterInfo *value_reg_info =
425 GetRegisterInfo(reg_kind: eRegisterKindLLDB, reg_num: reg);
426 if (value_reg_info == nullptr)
427 success = false;
428 else
429 success = SetPrimordialRegister(reg_info: value_reg_info, gdb_comm);
430 }
431 } else {
432 // This is an actual register, write it
433 success = SetPrimordialRegister(reg_info, gdb_comm);
434 }
435
436 // Check if writing this register will invalidate any other register
437 // values? If so, invalidate them
438 if (reg_info->invalidate_regs) {
439 for (uint32_t idx = 0, reg = reg_info->invalidate_regs[0];
440 reg != LLDB_INVALID_REGNUM;
441 reg = reg_info->invalidate_regs[++idx])
442 SetRegisterIsValid(reg: ConvertRegisterKindToRegisterNumber(
443 kind: eRegisterKindLLDB, num: reg),
444 valid: false);
445 }
446
447 if (success && should_reconfigure_registers &&
448 ReconfigureRegisterInfo())
449 InvalidateAllRegisters();
450
451 return success;
452 }
453 } else {
454 Log *log(GetLog(mask: GDBRLog::Thread | GDBRLog::Packets));
455 if (log) {
456 if (log->GetVerbose()) {
457 StreamString strm;
458 process->DumpPluginHistory(s&: strm);
459 LLDB_LOGF(log,
460 "error: failed to get packet sequence mutex, not sending "
461 "write register for \"%s\":\n%s",
462 reg_info->name, strm.GetData());
463 } else
464 LLDB_LOGF(log,
465 "error: failed to get packet sequence mutex, not sending "
466 "write register for \"%s\"",
467 reg_info->name);
468 }
469 }
470 }
471 return false;
472}
473
474bool GDBRemoteRegisterContext::ReadAllRegisterValues(
475 RegisterCheckpoint &reg_checkpoint) {
476 ExecutionContext exe_ctx(CalculateThread());
477
478 Process *process = exe_ctx.GetProcessPtr();
479 Thread *thread = exe_ctx.GetThreadPtr();
480 if (process == nullptr || thread == nullptr)
481 return false;
482
483 GDBRemoteCommunicationClient &gdb_comm(
484 ((ProcessGDBRemote *)process)->GetGDBRemote());
485
486 uint32_t save_id = 0;
487 if (gdb_comm.SaveRegisterState(tid: thread->GetProtocolID(), save_id)) {
488 reg_checkpoint.SetID(save_id);
489 reg_checkpoint.GetData().reset();
490 return true;
491 } else {
492 reg_checkpoint.SetID(0); // Invalid save ID is zero
493 return ReadAllRegisterValues(data_sp&: reg_checkpoint.GetData());
494 }
495}
496
497bool GDBRemoteRegisterContext::WriteAllRegisterValues(
498 const RegisterCheckpoint &reg_checkpoint) {
499 uint32_t save_id = reg_checkpoint.GetID();
500 if (save_id != 0) {
501 ExecutionContext exe_ctx(CalculateThread());
502
503 Process *process = exe_ctx.GetProcessPtr();
504 Thread *thread = exe_ctx.GetThreadPtr();
505 if (process == nullptr || thread == nullptr)
506 return false;
507
508 GDBRemoteCommunicationClient &gdb_comm(
509 ((ProcessGDBRemote *)process)->GetGDBRemote());
510
511 return gdb_comm.RestoreRegisterState(tid: m_thread.GetProtocolID(), save_id);
512 } else {
513 return WriteAllRegisterValues(data_sp: reg_checkpoint.GetData());
514 }
515}
516
517bool GDBRemoteRegisterContext::ReadAllRegisterValues(
518 lldb::WritableDataBufferSP &data_sp) {
519 ExecutionContext exe_ctx(CalculateThread());
520
521 Process *process = exe_ctx.GetProcessPtr();
522 Thread *thread = exe_ctx.GetThreadPtr();
523 if (process == nullptr || thread == nullptr)
524 return false;
525
526 GDBRemoteCommunicationClient &gdb_comm(
527 ((ProcessGDBRemote *)process)->GetGDBRemote());
528
529 const bool use_g_packet =
530 !gdb_comm.AvoidGPackets(process: (ProcessGDBRemote *)process);
531
532 GDBRemoteClientBase::Lock lock(gdb_comm);
533 if (lock) {
534 if (gdb_comm.SyncThreadState(tid: m_thread.GetProtocolID()))
535 InvalidateAllRegisters();
536
537 if (use_g_packet) {
538 if (DataBufferSP data_buffer =
539 gdb_comm.ReadAllRegisters(tid: m_thread.GetProtocolID())) {
540 data_sp = std::make_shared<DataBufferHeap>(args&: *data_buffer);
541 return true;
542 }
543 }
544
545 // We're going to read each register
546 // individually and store them as binary data in a buffer.
547 const RegisterInfo *reg_info;
548
549 for (uint32_t i = 0; (reg_info = GetRegisterInfoAtIndex(reg: i)) != nullptr;
550 i++) {
551 if (reg_info
552 ->value_regs) // skip registers that are slices of real registers
553 continue;
554 ReadRegisterBytes(reg_info);
555 // ReadRegisterBytes saves the contents of the register in to the
556 // m_reg_data buffer
557 }
558 data_sp = std::make_shared<DataBufferHeap>(
559 args: m_reg_data.GetDataStart(), args: m_reg_info_sp->GetRegisterDataByteSize());
560 return true;
561 } else {
562
563 Log *log(GetLog(mask: GDBRLog::Thread | GDBRLog::Packets));
564 if (log) {
565 if (log->GetVerbose()) {
566 StreamString strm;
567 process->DumpPluginHistory(s&: strm);
568 LLDB_LOGF(log,
569 "error: failed to get packet sequence mutex, not sending "
570 "read all registers:\n%s",
571 strm.GetData());
572 } else
573 LLDB_LOGF(log,
574 "error: failed to get packet sequence mutex, not sending "
575 "read all registers");
576 }
577 }
578
579 data_sp.reset();
580 return false;
581}
582
583bool GDBRemoteRegisterContext::WriteAllRegisterValues(
584 const lldb::DataBufferSP &data_sp) {
585 if (!data_sp || data_sp->GetBytes() == nullptr || data_sp->GetByteSize() == 0)
586 return false;
587
588 ExecutionContext exe_ctx(CalculateThread());
589
590 Process *process = exe_ctx.GetProcessPtr();
591 Thread *thread = exe_ctx.GetThreadPtr();
592 if (process == nullptr || thread == nullptr)
593 return false;
594
595 GDBRemoteCommunicationClient &gdb_comm(
596 ((ProcessGDBRemote *)process)->GetGDBRemote());
597
598 const bool use_g_packet =
599 !gdb_comm.AvoidGPackets(process: (ProcessGDBRemote *)process);
600
601 GDBRemoteClientBase::Lock lock(gdb_comm);
602 if (lock) {
603 // The data_sp contains the G response packet.
604 if (use_g_packet) {
605 if (gdb_comm.WriteAllRegisters(
606 tid: m_thread.GetProtocolID(),
607 data: {data_sp->GetBytes(), size_t(data_sp->GetByteSize())}))
608 return true;
609
610 uint32_t num_restored = 0;
611 // We need to manually go through all of the registers and restore them
612 // manually
613 DataExtractor restore_data(data_sp, m_reg_data.GetByteOrder(),
614 m_reg_data.GetAddressByteSize());
615
616 const RegisterInfo *reg_info;
617
618 // The g packet contents may either include the slice registers
619 // (registers defined in terms of other registers, e.g. eax is a subset
620 // of rax) or not. The slice registers should NOT be in the g packet,
621 // but some implementations may incorrectly include them.
622 //
623 // If the slice registers are included in the packet, we must step over
624 // the slice registers when parsing the packet -- relying on the
625 // RegisterInfo byte_offset field would be incorrect. If the slice
626 // registers are not included, then using the byte_offset values into the
627 // data buffer is the best way to find individual register values.
628
629 uint64_t size_including_slice_registers = 0;
630 uint64_t size_not_including_slice_registers = 0;
631 uint64_t size_by_highest_offset = 0;
632
633 for (uint32_t reg_idx = 0;
634 (reg_info = GetRegisterInfoAtIndex(reg: reg_idx)) != nullptr; ++reg_idx) {
635 size_including_slice_registers += reg_info->byte_size;
636 if (reg_info->value_regs == nullptr)
637 size_not_including_slice_registers += reg_info->byte_size;
638 if (reg_info->byte_offset >= size_by_highest_offset)
639 size_by_highest_offset = reg_info->byte_offset + reg_info->byte_size;
640 }
641
642 bool use_byte_offset_into_buffer;
643 if (size_by_highest_offset == restore_data.GetByteSize()) {
644 // The size of the packet agrees with the highest offset: + size in the
645 // register file
646 use_byte_offset_into_buffer = true;
647 } else if (size_not_including_slice_registers ==
648 restore_data.GetByteSize()) {
649 // The size of the packet is the same as concatenating all of the
650 // registers sequentially, skipping the slice registers
651 use_byte_offset_into_buffer = true;
652 } else if (size_including_slice_registers == restore_data.GetByteSize()) {
653 // The slice registers are present in the packet (when they shouldn't
654 // be). Don't try to use the RegisterInfo byte_offset into the
655 // restore_data, it will point to the wrong place.
656 use_byte_offset_into_buffer = false;
657 } else {
658 // None of our expected sizes match the actual g packet data we're
659 // looking at. The most conservative approach here is to use the
660 // running total byte offset.
661 use_byte_offset_into_buffer = false;
662 }
663
664 // In case our register definitions don't include the correct offsets,
665 // keep track of the size of each reg & compute offset based on that.
666 uint32_t running_byte_offset = 0;
667 for (uint32_t reg_idx = 0;
668 (reg_info = GetRegisterInfoAtIndex(reg: reg_idx)) != nullptr;
669 ++reg_idx, running_byte_offset += reg_info->byte_size) {
670 // Skip composite aka slice registers (e.g. eax is a slice of rax).
671 if (reg_info->value_regs)
672 continue;
673
674 const uint32_t reg = reg_info->kinds[eRegisterKindLLDB];
675
676 uint32_t register_offset;
677 if (use_byte_offset_into_buffer) {
678 register_offset = reg_info->byte_offset;
679 } else {
680 register_offset = running_byte_offset;
681 }
682
683 const uint32_t reg_byte_size = reg_info->byte_size;
684
685 const uint8_t *restore_src =
686 restore_data.PeekData(offset: register_offset, length: reg_byte_size);
687 if (restore_src) {
688 SetRegisterIsValid(reg, valid: false);
689 if (gdb_comm.WriteRegister(
690 tid: m_thread.GetProtocolID(),
691 reg_num: reg_info->kinds[eRegisterKindProcessPlugin],
692 data: {restore_src, reg_byte_size}))
693 ++num_restored;
694 }
695 }
696 return num_restored > 0;
697 } else {
698 // For the use_g_packet == false case, we're going to write each register
699 // individually. The data buffer is binary data in this case, instead of
700 // ascii characters.
701
702 bool arm64_debugserver = false;
703 if (m_thread.GetProcess().get()) {
704 const ArchSpec &arch =
705 m_thread.GetProcess()->GetTarget().GetArchitecture();
706 if (arch.IsValid() && (arch.GetMachine() == llvm::Triple::aarch64 ||
707 arch.GetMachine() == llvm::Triple::aarch64_32) &&
708 arch.GetTriple().getVendor() == llvm::Triple::Apple &&
709 arch.GetTriple().getOS() == llvm::Triple::IOS) {
710 arm64_debugserver = true;
711 }
712 }
713 uint32_t num_restored = 0;
714 const RegisterInfo *reg_info;
715 for (uint32_t i = 0; (reg_info = GetRegisterInfoAtIndex(reg: i)) != nullptr;
716 i++) {
717 if (reg_info->value_regs) // skip registers that are slices of real
718 // registers
719 continue;
720 // Skip the fpsr and fpcr floating point status/control register
721 // writing to work around a bug in an older version of debugserver that
722 // would lead to register context corruption when writing fpsr/fpcr.
723 if (arm64_debugserver && (strcmp(s1: reg_info->name, s2: "fpsr") == 0 ||
724 strcmp(s1: reg_info->name, s2: "fpcr") == 0)) {
725 continue;
726 }
727
728 SetRegisterIsValid(reg_info, valid: false);
729 if (gdb_comm.WriteRegister(tid: m_thread.GetProtocolID(),
730 reg_num: reg_info->kinds[eRegisterKindProcessPlugin],
731 data: {data_sp->GetBytes() + reg_info->byte_offset,
732 reg_info->byte_size}))
733 ++num_restored;
734 }
735 return num_restored > 0;
736 }
737 } else {
738 Log *log(GetLog(mask: GDBRLog::Thread | GDBRLog::Packets));
739 if (log) {
740 if (log->GetVerbose()) {
741 StreamString strm;
742 process->DumpPluginHistory(s&: strm);
743 LLDB_LOGF(log,
744 "error: failed to get packet sequence mutex, not sending "
745 "write all registers:\n%s",
746 strm.GetData());
747 } else
748 LLDB_LOGF(log,
749 "error: failed to get packet sequence mutex, not sending "
750 "write all registers");
751 }
752 }
753 return false;
754}
755
756uint32_t GDBRemoteRegisterContext::ConvertRegisterKindToRegisterNumber(
757 lldb::RegisterKind kind, uint32_t num) {
758 return m_reg_info_sp->ConvertRegisterKindToRegisterNumber(kind, num);
759}
760
761bool GDBRemoteRegisterContext::RegisterWriteCausesReconfigure(
762 const llvm::StringRef name) {
763 ExecutionContext exe_ctx(CalculateThread());
764 const Architecture *architecture =
765 exe_ctx.GetProcessRef().GetTarget().GetArchitecturePlugin();
766 return architecture && architecture->RegisterWriteCausesReconfigure(name);
767}
768
769bool GDBRemoteRegisterContext::ReconfigureRegisterInfo() {
770 ExecutionContext exe_ctx(CalculateThread());
771 const Architecture *architecture =
772 exe_ctx.GetProcessRef().GetTarget().GetArchitecturePlugin();
773 if (architecture)
774 return architecture->ReconfigureRegisterInfo(reg_info&: *(m_reg_info_sp.get()),
775 reg_data&: m_reg_data, reg_context&: *this);
776 return false;
777}
778

source code of lldb/source/Plugins/Process/gdb-remote/GDBRemoteRegisterContext.cpp