1//===-- ThreadKDP.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 "ThreadKDP.h"
10
11#include "lldb/Host/SafeMachO.h"
12
13#include "lldb/Breakpoint/Watchpoint.h"
14#include "lldb/Target/Process.h"
15#include "lldb/Target/RegisterContext.h"
16#include "lldb/Target/StopInfo.h"
17#include "lldb/Target/Target.h"
18#include "lldb/Target/Unwind.h"
19#include "lldb/Utility/ArchSpec.h"
20#include "lldb/Utility/DataExtractor.h"
21#include "lldb/Utility/State.h"
22#include "lldb/Utility/StreamString.h"
23
24#include "Plugins/Process/Utility/StopInfoMachException.h"
25#include "ProcessKDP.h"
26#include "ProcessKDPLog.h"
27#include "RegisterContextKDP_arm.h"
28#include "RegisterContextKDP_arm64.h"
29#include "RegisterContextKDP_i386.h"
30#include "RegisterContextKDP_x86_64.h"
31
32#include <memory>
33
34using namespace lldb;
35using namespace lldb_private;
36
37// Thread Registers
38
39ThreadKDP::ThreadKDP(Process &process, lldb::tid_t tid)
40 : Thread(process, tid), m_thread_name(), m_dispatch_queue_name(),
41 m_thread_dispatch_qaddr(LLDB_INVALID_ADDRESS) {
42 Log *log = GetLog(mask: KDPLog::Thread);
43 LLDB_LOG(log, "this = {0}, tid = {1:x}", this, GetID());
44}
45
46ThreadKDP::~ThreadKDP() {
47 Log *log = GetLog(mask: KDPLog::Thread);
48 LLDB_LOG(log, "this = {0}, tid = {1:x}", this, GetID());
49 DestroyThread();
50}
51
52const char *ThreadKDP::GetName() {
53 if (m_thread_name.empty())
54 return nullptr;
55 return m_thread_name.c_str();
56}
57
58const char *ThreadKDP::GetQueueName() { return nullptr; }
59
60void ThreadKDP::RefreshStateAfterStop() {
61 // Invalidate all registers in our register context. We don't set "force" to
62 // true because the stop reply packet might have had some register values
63 // that were expedited and these will already be copied into the register
64 // context by the time this function gets called. The KDPRegisterContext
65 // class has been made smart enough to detect when it needs to invalidate
66 // which registers are valid by putting hooks in the register read and
67 // register supply functions where they check the process stop ID and do the
68 // right thing.
69 const bool force = false;
70 lldb::RegisterContextSP reg_ctx_sp(GetRegisterContext());
71 if (reg_ctx_sp)
72 reg_ctx_sp->InvalidateIfNeeded(force);
73}
74
75bool ThreadKDP::ThreadIDIsValid(lldb::tid_t thread) { return thread != 0; }
76
77void ThreadKDP::Dump(Log *log, uint32_t index) {}
78
79bool ThreadKDP::ShouldStop(bool &step_more) { return true; }
80lldb::RegisterContextSP ThreadKDP::GetRegisterContext() {
81 if (!m_reg_context_sp)
82 m_reg_context_sp = CreateRegisterContextForFrame(frame: nullptr);
83 return m_reg_context_sp;
84}
85
86lldb::RegisterContextSP
87ThreadKDP::CreateRegisterContextForFrame(StackFrame *frame) {
88 lldb::RegisterContextSP reg_ctx_sp;
89 uint32_t concrete_frame_idx = 0;
90
91 if (frame)
92 concrete_frame_idx = frame->GetConcreteFrameIndex();
93
94 if (concrete_frame_idx == 0) {
95 ProcessSP process_sp(CalculateProcess());
96 if (process_sp) {
97 switch (static_cast<ProcessKDP *>(process_sp.get())
98 ->GetCommunication()
99 .GetCPUType()) {
100 case llvm::MachO::CPU_TYPE_ARM:
101 reg_ctx_sp =
102 std::make_shared<RegisterContextKDP_arm>(args&: *this, args&: concrete_frame_idx);
103 break;
104 case llvm::MachO::CPU_TYPE_ARM64:
105 reg_ctx_sp = std::make_shared<RegisterContextKDP_arm64>(
106 args&: *this, args&: concrete_frame_idx);
107 break;
108 case llvm::MachO::CPU_TYPE_I386:
109 reg_ctx_sp = std::make_shared<RegisterContextKDP_i386>(
110 args&: *this, args&: concrete_frame_idx);
111 break;
112 case llvm::MachO::CPU_TYPE_X86_64:
113 reg_ctx_sp = std::make_shared<RegisterContextKDP_x86_64>(
114 args&: *this, args&: concrete_frame_idx);
115 break;
116 default:
117 llvm_unreachable("Add CPU type support in KDP");
118 }
119 }
120 } else {
121 reg_ctx_sp = GetUnwinder().CreateRegisterContextForFrame(frame);
122 }
123 return reg_ctx_sp;
124}
125
126bool ThreadKDP::CalculateStopInfo() {
127 ProcessSP process_sp(GetProcess());
128 if (process_sp) {
129 if (m_cached_stop_info_sp) {
130 SetStopInfo(m_cached_stop_info_sp);
131 } else {
132 SetStopInfo(StopInfo::CreateStopReasonWithSignal(thread&: *this, SIGSTOP));
133 }
134 return true;
135 }
136 return false;
137}
138
139void ThreadKDP::SetStopInfoFrom_KDP_EXCEPTION(
140 const DataExtractor &exc_reply_packet) {
141 lldb::offset_t offset = 0;
142 uint8_t reply_command = exc_reply_packet.GetU8(offset_ptr: &offset);
143 if (reply_command == CommunicationKDP::KDP_EXCEPTION) {
144 offset = 8;
145 const uint32_t count = exc_reply_packet.GetU32(offset_ptr: &offset);
146 if (count >= 1) {
147 // const uint32_t cpu = exc_reply_packet.GetU32 (&offset);
148 offset += 4; // Skip the useless CPU field
149 const uint32_t exc_type = exc_reply_packet.GetU32(offset_ptr: &offset);
150 const uint32_t exc_code = exc_reply_packet.GetU32(offset_ptr: &offset);
151 const uint32_t exc_subcode = exc_reply_packet.GetU32(offset_ptr: &offset);
152 // We have to make a copy of the stop info because the thread list will
153 // iterate through the threads and clear all stop infos..
154
155 // Let the StopInfoMachException::CreateStopReasonWithMachException()
156 // function update the PC if needed as we might hit a software breakpoint
157 // and need to decrement the PC (i386 and x86_64 need this) and KDP
158 // doesn't do this for us.
159 const bool pc_already_adjusted = false;
160 const bool adjust_pc_if_needed = true;
161
162 m_cached_stop_info_sp =
163 StopInfoMachException::CreateStopReasonWithMachException(
164 thread&: *this, exc_type, exc_data_count: 2, exc_code, exc_sub_code: exc_subcode, exc_sub_sub_code: 0, pc_already_adjusted,
165 adjust_pc_if_needed);
166 }
167 }
168}
169

source code of lldb/source/Plugins/Process/MacOSX-Kernel/ThreadKDP.cpp