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