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
31using namespace lldb;
32using namespace lldb_private;
33
34// Thread Registers
35
36ThreadMachCore::ThreadMachCore(Process &process, lldb::tid_t tid,
37 uint32_t objfile_lc_thread_idx)
38 : Thread(process, tid), m_thread_name(), m_dispatch_queue_name(),
39 m_thread_dispatch_qaddr(LLDB_INVALID_ADDRESS), m_thread_reg_ctx_sp(),
40 m_objfile_lc_thread_idx(objfile_lc_thread_idx) {}
41
42ThreadMachCore::~ThreadMachCore() { DestroyThread(); }
43
44const char *ThreadMachCore::GetName() {
45 if (m_thread_name.empty())
46 return nullptr;
47 return m_thread_name.c_str();
48}
49
50void ThreadMachCore::RefreshStateAfterStop() {
51 // Invalidate all registers in our register context. We don't set "force" to
52 // true because the stop reply packet might have had some register values
53 // that were expedited and these will already be copied into the register
54 // context by the time this function gets called. The KDPRegisterContext
55 // class has been made smart enough to detect when it needs to invalidate
56 // which registers are valid by putting hooks in the register read and
57 // register supply functions where they check the process stop ID and do the
58 // right thing.
59 const bool force = false;
60 GetRegisterContext()->InvalidateIfNeeded(force);
61}
62
63bool ThreadMachCore::ThreadIDIsValid(lldb::tid_t thread) { return thread != 0; }
64
65lldb::RegisterContextSP ThreadMachCore::GetRegisterContext() {
66 if (!m_reg_context_sp)
67 m_reg_context_sp = CreateRegisterContextForFrame(frame: nullptr);
68 return m_reg_context_sp;
69}
70
71lldb::RegisterContextSP
72ThreadMachCore::CreateRegisterContextForFrame(StackFrame *frame) {
73 lldb::RegisterContextSP reg_ctx_sp;
74 uint32_t concrete_frame_idx = 0;
75
76 if (frame)
77 concrete_frame_idx = frame->GetConcreteFrameIndex();
78
79 if (concrete_frame_idx == 0) {
80 if (!m_thread_reg_ctx_sp) {
81 ProcessSP process_sp(GetProcess());
82
83 ObjectFile *core_objfile =
84 static_cast<ProcessMachCore *>(process_sp.get())->GetCoreObjectFile();
85 if (core_objfile)
86 m_thread_reg_ctx_sp = core_objfile->GetThreadContextAtIndex(
87 idx: m_objfile_lc_thread_idx, thread&: *this);
88 }
89 reg_ctx_sp = m_thread_reg_ctx_sp;
90 } else {
91 reg_ctx_sp = GetUnwinder().CreateRegisterContextForFrame(frame);
92 }
93 return reg_ctx_sp;
94}
95
96static bool IsCrashExceptionClass(AppleArm64ExceptionClass EC) {
97 switch (EC) {
98 case AppleArm64ExceptionClass::ESR_EC_UNCATEGORIZED:
99 case AppleArm64ExceptionClass::ESR_EC_SVC_32:
100 case AppleArm64ExceptionClass::ESR_EC_SVC_64:
101 // In the ARM exception model, a process takes an exception when asking the
102 // kernel to service a system call. Don't treat this like a crash.
103 return false;
104 default:
105 return true;
106 }
107}
108
109bool ThreadMachCore::CalculateStopInfo() {
110 ProcessSP process_sp(GetProcess());
111 if (process_sp) {
112 StopInfoSP stop_info;
113 RegisterContextSP reg_ctx_sp = GetRegisterContext();
114
115 if (reg_ctx_sp) {
116 Target &target = process_sp->GetTarget();
117 const ArchSpec arch_spec = target.GetArchitecture();
118 const uint32_t cputype = arch_spec.GetMachOCPUType();
119
120 if (cputype == llvm::MachO::CPU_TYPE_ARM64 ||
121 cputype == llvm::MachO::CPU_TYPE_ARM64_32) {
122 const RegisterInfo *esr_info = reg_ctx_sp->GetRegisterInfoByName(reg_name: "esr");
123 const RegisterInfo *far_info = reg_ctx_sp->GetRegisterInfoByName(reg_name: "far");
124 RegisterValue esr, far;
125 if (reg_ctx_sp->ReadRegister(reg_info: esr_info, reg_value&: esr) &&
126 reg_ctx_sp->ReadRegister(reg_info: far_info, reg_value&: far)) {
127 const uint32_t esr_val = esr.GetAsUInt32();
128 const AppleArm64ExceptionClass exception_class =
129 getAppleArm64ExceptionClass(esr: esr_val);
130 if (IsCrashExceptionClass(EC: exception_class)) {
131 StreamString S;
132 S.Printf(format: "%s (fault address: 0x%" PRIx64 ")",
133 toString(EC: exception_class), far.GetAsUInt64());
134 stop_info =
135 StopInfo::CreateStopReasonWithException(thread&: *this, description: S.GetData());
136 }
137 }
138 }
139 }
140
141 // Set a stop reason for crashing threads only so that they get selected
142 // preferentially.
143 if (stop_info)
144 SetStopInfo(stop_info);
145 return true;
146 }
147 return false;
148}
149

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