1//===-- ThreadMachCore.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 <optional>
10#include <string>
11#include <vector>
12
13#include "RegisterContextUnifiedCore.h"
14#include "ThreadMachCore.h"
15
16#include "lldb/Breakpoint/Watchpoint.h"
17#include "lldb/Host/SafeMachO.h"
18#include "lldb/Symbol/ObjectFile.h"
19#include "lldb/Target/AppleArm64ExceptionClass.h"
20#include "lldb/Target/DynamicRegisterInfo.h"
21#include "lldb/Target/Process.h"
22#include "lldb/Target/RegisterContext.h"
23#include "lldb/Target/StopInfo.h"
24#include "lldb/Target/Target.h"
25#include "lldb/Target/Unwind.h"
26#include "lldb/Utility/ArchSpec.h"
27#include "lldb/Utility/DataExtractor.h"
28#include "lldb/Utility/RegisterValue.h"
29#include "lldb/Utility/State.h"
30#include "lldb/Utility/StreamString.h"
31#include "lldb/Utility/StructuredData.h"
32
33#include "ProcessMachCore.h"
34//#include "RegisterContextKDP_arm.h"
35//#include "RegisterContextKDP_i386.h"
36//#include "RegisterContextKDP_x86_64.h"
37
38using namespace lldb;
39using namespace lldb_private;
40
41// Thread Registers
42
43ThreadMachCore::ThreadMachCore(Process &process, lldb::tid_t tid,
44 uint32_t objfile_lc_thread_idx)
45 : Thread(process, tid), m_thread_name(), m_dispatch_queue_name(),
46 m_thread_dispatch_qaddr(LLDB_INVALID_ADDRESS), m_thread_reg_ctx_sp(),
47 m_objfile_lc_thread_idx(objfile_lc_thread_idx) {}
48
49ThreadMachCore::~ThreadMachCore() { DestroyThread(); }
50
51const char *ThreadMachCore::GetName() {
52 if (m_thread_name.empty())
53 return nullptr;
54 return m_thread_name.c_str();
55}
56
57void ThreadMachCore::RefreshStateAfterStop() {
58 // Invalidate all registers in our register context. We don't set "force" to
59 // true because the stop reply packet might have had some register values
60 // that were expedited and these will already be copied into the register
61 // context by the time this function gets called. The KDPRegisterContext
62 // class has been made smart enough to detect when it needs to invalidate
63 // which registers are valid by putting hooks in the register read and
64 // register supply functions where they check the process stop ID and do the
65 // right thing.
66 const bool force = false;
67 GetRegisterContext()->InvalidateIfNeeded(force);
68}
69
70bool ThreadMachCore::ThreadIDIsValid(lldb::tid_t thread) { return thread != 0; }
71
72lldb::RegisterContextSP ThreadMachCore::GetRegisterContext() {
73 if (!m_reg_context_sp)
74 m_reg_context_sp = CreateRegisterContextForFrame(frame: nullptr);
75 return m_reg_context_sp;
76}
77
78lldb::RegisterContextSP
79ThreadMachCore::CreateRegisterContextForFrame(StackFrame *frame) {
80 uint32_t concrete_frame_idx = 0;
81
82 if (frame)
83 concrete_frame_idx = frame->GetConcreteFrameIndex();
84 if (concrete_frame_idx > 0)
85 return GetUnwinder().CreateRegisterContextForFrame(frame);
86
87 if (m_thread_reg_ctx_sp)
88 return m_thread_reg_ctx_sp;
89
90 ProcessSP process_sp(GetProcess());
91 assert(process_sp);
92
93 ObjectFile *core_objfile =
94 static_cast<ProcessMachCore *>(process_sp.get())->GetCoreObjectFile();
95 if (!core_objfile)
96 return {};
97
98 RegisterContextSP core_thread_regctx_sp =
99 core_objfile->GetThreadContextAtIndex(idx: m_objfile_lc_thread_idx, thread&: *this);
100
101 if (!core_thread_regctx_sp)
102 return {};
103
104 StructuredData::ObjectSP process_md_sp =
105 core_objfile->GetCorefileProcessMetadata();
106
107 StructuredData::ObjectSP thread_md_sp;
108 if (process_md_sp && process_md_sp->GetAsDictionary() &&
109 process_md_sp->GetAsDictionary()->HasKey(key: "threads")) {
110 StructuredData::Array *threads = process_md_sp->GetAsDictionary()
111 ->GetValueForKey(key: "threads")
112 ->GetAsArray();
113 if (threads && threads->GetSize() == core_objfile->GetNumThreadContexts()) {
114 StructuredData::ObjectSP thread_sp =
115 threads->GetItemAtIndex(idx: m_objfile_lc_thread_idx);
116 if (thread_sp && thread_sp->GetAsDictionary())
117 thread_md_sp = thread_sp;
118 }
119 }
120 m_thread_reg_ctx_sp = std::make_shared<RegisterContextUnifiedCore>(
121 args&: *this, args&: concrete_frame_idx, args&: core_thread_regctx_sp, args&: thread_md_sp);
122
123 return m_thread_reg_ctx_sp;
124}
125
126static bool IsCrashExceptionClass(AppleArm64ExceptionClass EC) {
127 switch (EC) {
128 case AppleArm64ExceptionClass::ESR_EC_UNCATEGORIZED:
129 case AppleArm64ExceptionClass::ESR_EC_SVC_32:
130 case AppleArm64ExceptionClass::ESR_EC_SVC_64:
131 // In the ARM exception model, a process takes an exception when asking the
132 // kernel to service a system call. Don't treat this like a crash.
133 return false;
134 default:
135 return true;
136 }
137}
138
139bool ThreadMachCore::CalculateStopInfo() {
140 ProcessSP process_sp(GetProcess());
141 if (process_sp) {
142 StopInfoSP stop_info;
143 RegisterContextSP reg_ctx_sp = GetRegisterContext();
144
145 if (reg_ctx_sp) {
146 Target &target = process_sp->GetTarget();
147 const ArchSpec arch_spec = target.GetArchitecture();
148 const uint32_t cputype = arch_spec.GetMachOCPUType();
149
150 if (cputype == llvm::MachO::CPU_TYPE_ARM64 ||
151 cputype == llvm::MachO::CPU_TYPE_ARM64_32) {
152 const RegisterInfo *esr_info = reg_ctx_sp->GetRegisterInfoByName(reg_name: "esr");
153 const RegisterInfo *far_info = reg_ctx_sp->GetRegisterInfoByName(reg_name: "far");
154 RegisterValue esr, far;
155 if (reg_ctx_sp->ReadRegister(reg_info: esr_info, reg_value&: esr) &&
156 reg_ctx_sp->ReadRegister(reg_info: far_info, reg_value&: far)) {
157 const uint32_t esr_val = esr.GetAsUInt32();
158 const AppleArm64ExceptionClass exception_class =
159 getAppleArm64ExceptionClass(esr: esr_val);
160 if (IsCrashExceptionClass(EC: exception_class)) {
161 StreamString S;
162 S.Printf(format: "%s (fault address: 0x%" PRIx64 ")",
163 toString(EC: exception_class), far.GetAsUInt64());
164 stop_info =
165 StopInfo::CreateStopReasonWithException(thread&: *this, description: S.GetData());
166 }
167 }
168 }
169 }
170
171 // Set a stop reason for crashing threads only so that they get selected
172 // preferentially.
173 if (stop_info)
174 SetStopInfo(stop_info);
175 return true;
176 }
177 return false;
178}
179

source code of lldb/source/Plugins/Process/mach-core/ThreadMachCore.cpp