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

   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
  36 ThreadMachCore::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
  42 ThreadMachCore::~ThreadMachCore() { DestroyThread(); }
  43
  44 const char *ThreadMachCore::GetName() {
  45   if (m_thread_name.empty())
  46     return nullptr;
  47   return m_thread_name.c_str();
  48 }
  49
  50 void 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
  63 bool ThreadMachCore::ThreadIDIsValid(lldb::tid_t thread) { return thread != 0; }
  64
  65 lldb::RegisterContextSP ThreadMachCore::GetRegisterContext() {
  66   if (!m_reg_context_sp)
  67     m_reg_context_sp = CreateRegisterContextForFrame(nullptr);
  68   return m_reg_context_sp;
  69 }
  70
  71 lldb::RegisterContextSP
  72 ThreadMachCore::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             m_objfile_lc_thread_idx, *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
  96 static 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
 109 bool 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("esr");
 123         const RegisterInfo *far_info = reg_ctx_sp->GetRegisterInfoByName("far");
 124         RegisterValue esr, far;
 125         if (reg_ctx_sp->ReadRegister(esr_info, esr) &&
 126             reg_ctx_sp->ReadRegister(far_info, far)) {
 127           const uint32_t esr_val = esr.GetAsUInt32();
 128           const AppleArm64ExceptionClass exception_class =
 129               getAppleArm64ExceptionClass(esr_val);
 130           if (IsCrashExceptionClass(exception_class)) {
 131             StreamString S;
 132             S.Printf("%s (fault address: 0x%" PRIx64 ")",
 133                      toString(exception_class), far.GetAsUInt64());
 134             stop_info =
 135                 StopInfo::CreateStopReasonWithException(*this, 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 }