146 lines · cpp
1//===-- NativeProcessSoftwareSingleStep.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-exception6//7//===----------------------------------------------------------------------===//8 9#include "NativeProcessSoftwareSingleStep.h"10 11#include "lldb/Core/EmulateInstruction.h"12#include "lldb/Host/common/NativeRegisterContext.h"13#include "lldb/Utility/RegisterValue.h"14 15#include <unordered_map>16 17using namespace lldb;18using namespace lldb_private;19 20namespace {21 22struct EmulatorBaton {23 NativeProcessProtocol &m_process;24 NativeRegisterContext &m_reg_context;25 26 // eRegisterKindDWARF -> RegsiterValue27 std::unordered_map<uint32_t, RegisterValue> m_register_values;28 29 EmulatorBaton(NativeProcessProtocol &process,30 NativeRegisterContext ®_context)31 : m_process(process), m_reg_context(reg_context) {}32};33 34} // anonymous namespace35 36static size_t ReadMemoryCallback(EmulateInstruction *instruction, void *baton,37 const EmulateInstruction::Context &context,38 lldb::addr_t addr, void *dst, size_t length) {39 EmulatorBaton *emulator_baton = static_cast<EmulatorBaton *>(baton);40 41 size_t bytes_read;42 emulator_baton->m_process.ReadMemory(addr, dst, length, bytes_read);43 return bytes_read;44}45 46static bool ReadRegisterCallback(EmulateInstruction *instruction, void *baton,47 const RegisterInfo *reg_info,48 RegisterValue ®_value) {49 EmulatorBaton *emulator_baton = static_cast<EmulatorBaton *>(baton);50 51 auto it = emulator_baton->m_register_values.find(52 reg_info->kinds[eRegisterKindDWARF]);53 if (it != emulator_baton->m_register_values.end()) {54 reg_value = it->second;55 return true;56 }57 58 // The emulator only fill in the dwarf regsiter numbers (and in some case the59 // generic register numbers). Get the full register info from the register60 // context based on the dwarf register numbers.61 const RegisterInfo *full_reg_info =62 emulator_baton->m_reg_context.GetRegisterInfo(63 eRegisterKindDWARF, reg_info->kinds[eRegisterKindDWARF]);64 65 Status error =66 emulator_baton->m_reg_context.ReadRegister(full_reg_info, reg_value);67 if (error.Success())68 return true;69 70 return false;71}72 73static bool WriteRegisterCallback(EmulateInstruction *instruction, void *baton,74 const EmulateInstruction::Context &context,75 const RegisterInfo *reg_info,76 const RegisterValue ®_value) {77 EmulatorBaton *emulator_baton = static_cast<EmulatorBaton *>(baton);78 emulator_baton->m_register_values[reg_info->kinds[eRegisterKindDWARF]] =79 reg_value;80 return true;81}82 83static size_t WriteMemoryCallback(EmulateInstruction *instruction, void *baton,84 const EmulateInstruction::Context &context,85 lldb::addr_t addr, const void *dst,86 size_t length) {87 return length;88}89 90static Status SetSoftwareBreakpoint(lldb::addr_t bp_addr, unsigned bp_size,91 NativeProcessProtocol &process) {92 Status error;93 error = process.SetBreakpoint(bp_addr, bp_size, /*hardware=*/false);94 95 // If setting the breakpoint fails because pc is out of the address96 // space, ignore it and let the debugee segfault.97 if (error.GetError() == EIO || error.GetError() == EFAULT)98 return Status();99 if (error.Fail())100 return error;101 102 return Status();103}104 105Status NativeProcessSoftwareSingleStep::SetupSoftwareSingleStepping(106 NativeThreadProtocol &thread) {107 Status error;108 NativeProcessProtocol &process = thread.GetProcess();109 NativeRegisterContext ®ister_context = thread.GetRegisterContext();110 const ArchSpec &arch = process.GetArchitecture();111 112 std::unique_ptr<EmulateInstruction> emulator_up(113 EmulateInstruction::FindPlugin(arch, eInstructionTypePCModifying,114 nullptr));115 if (emulator_up == nullptr)116 return Status::FromErrorString("Instruction emulator not found!");117 118 EmulatorBaton baton(process, register_context);119 emulator_up->SetBaton(&baton);120 emulator_up->SetReadMemCallback(&ReadMemoryCallback);121 emulator_up->SetReadRegCallback(&ReadRegisterCallback);122 emulator_up->SetWriteMemCallback(&WriteMemoryCallback);123 emulator_up->SetWriteRegCallback(&WriteRegisterCallback);124 125 auto bp_locaions_predictor =126 EmulateInstruction::CreateBreakpointLocationPredictor(127 std::move(emulator_up));128 129 auto bp_locations = bp_locaions_predictor->GetBreakpointLocations(error);130 if (error.Fail())131 return error;132 133 for (auto &&bp_addr : bp_locations) {134 auto bp_size = bp_locaions_predictor->GetBreakpointSize(bp_addr);135 if (auto err = bp_size.takeError())136 return Status(toString(std::move(err)));137 138 error = SetSoftwareBreakpoint(bp_addr, *bp_size, process);139 if (error.Fail())140 return error;141 }142 143 m_threads_stepping_with_breakpoint.insert({thread.GetID(), bp_locations});144 return error;145}146