lldb/source/Plugins/Process/Windows/Common/NativeRegisterContextWindows_WoW64.cpp

//===-- NativeRegisterContextWindows_WoW64.cpp ----- ------------*- C++ -*-===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//

#if defined(_WIN64)

#include "NativeRegisterContextWindows_WoW64.h"

#include "NativeThreadWindows.h"
#include "Plugins/Process/Utility/RegisterContextWindows_i386.h"
#include "ProcessWindowsLog.h"
#include "lldb/Host/HostInfo.h"
#include "lldb/Host/HostThread.h"
#include "lldb/Host/Windows/HostThreadWindows.h"
#include "lldb/Host/windows/windows.h"

#include "lldb/Utility/Log.h"
#include "lldb/Utility/RegisterValue.h"
#include "llvm/ADT/STLExtras.h"

using namespace lldb;
using namespace lldb_private;

#define REG_CONTEXT_SIZE sizeof(::WOW64_CONTEXT)

namespace {
static const uint32_t g_gpr_regnums_WoW64[] = {
    lldb_eax_i386,      lldb_ebx_i386,    lldb_ecx_i386, lldb_edx_i386,
    lldb_edi_i386,      lldb_esi_i386,    lldb_ebp_i386, lldb_esp_i386,
    lldb_eip_i386,      lldb_eflags_i386, lldb_cs_i386,  lldb_fs_i386,
    lldb_gs_i386,       lldb_ss_i386,     lldb_ds_i386,  lldb_es_i386,
    LLDB_INVALID_REGNUM // Register set must be terminated with this flag.
};

static const RegisterSet g_reg_sets_WoW64[] = {
    {"General Purpose Registers", "gpr",
     llvm::array_lengthof(g_gpr_regnums_WoW64) - 1, g_gpr_regnums_WoW64},
};
enum { k_num_register_sets = 1 };

static const DWORD kWoW64ContextFlags =
    WOW64_CONTEXT_CONTROL | WOW64_CONTEXT_INTEGER | WOW64_CONTEXT_SEGMENTS;

} // namespace

static RegisterInfoInterface *
CreateRegisterInfoInterface(const ArchSpec &target_arch) {
  // i686 32bit instruction set.
  assert((target_arch.GetAddressByteSize() == 4 &&
          HostInfo::GetArchitecture().GetAddressByteSize() == 8) &&
         "Register setting path assumes this is a 64-bit host");
  return new RegisterContextWindows_i386(target_arch);
}

static Status GetWoW64ThreadContextHelper(lldb::thread_t thread_handle,
                                          PWOW64_CONTEXT context_ptr) {
  Log *log = ProcessWindowsLog::GetLogIfAny(WINDOWS_LOG_REGISTERS);
  Status error;
  memset(context_ptr, 0, sizeof(::WOW64_CONTEXT));
  context_ptr->ContextFlags = kWoW64ContextFlags;
  if (!::Wow64GetThreadContext(thread_handle, context_ptr)) {
    error.SetError(GetLastError(), eErrorTypeWin32);
    LLDB_LOG(log, "{0} Wow64GetThreadContext failed with error {1}",
             __FUNCTION__, error);
    return error;
  }
  return Status();
}

static Status SetWoW64ThreadContextHelper(lldb::thread_t thread_handle,
                                          PWOW64_CONTEXT context_ptr) {
  Log *log = ProcessWindowsLog::GetLogIfAny(WINDOWS_LOG_REGISTERS);
  Status error;
  if (!::Wow64SetThreadContext(thread_handle, context_ptr)) {
    error.SetError(GetLastError(), eErrorTypeWin32);
    LLDB_LOG(log, "{0} Wow64SetThreadContext failed with error {1}",
             __FUNCTION__, error);
    return error;
  }
  return Status();
}

NativeRegisterContextWindows_WoW64::NativeRegisterContextWindows_WoW64(
    const ArchSpec &target_arch, NativeThreadProtocol &native_thread)
    : NativeRegisterContextWindows(native_thread,
                                   CreateRegisterInfoInterface(target_arch)) {}

bool NativeRegisterContextWindows_WoW64::IsGPR(uint32_t reg_index) const {
  return (reg_index >= k_first_gpr_i386 && reg_index < k_first_alias_i386);
}

uint32_t NativeRegisterContextWindows_WoW64::GetRegisterSetCount() const {
  return k_num_register_sets;
}

const RegisterSet *
NativeRegisterContextWindows_WoW64::GetRegisterSet(uint32_t set_index) const {
  if (set_index >= k_num_register_sets)
    return nullptr;
  return &g_reg_sets_WoW64[set_index];
}

Status NativeRegisterContextWindows_WoW64::GPRRead(const uint32_t reg,
                                                   RegisterValue &reg_value) {
  ::WOW64_CONTEXT tls_context;
  Status error = GetWoW64ThreadContextHelper(GetThreadHandle(), &tls_context);
  if (error.Fail())
    return error;

  switch (reg) {
  case lldb_eax_i386:
    reg_value.SetUInt32(tls_context.Eax);
    break;
  case lldb_ebx_i386:
    reg_value.SetUInt32(tls_context.Ebx);
    break;
  case lldb_ecx_i386:
    reg_value.SetUInt32(tls_context.Ecx);
    break;
  case lldb_edx_i386:
    reg_value.SetUInt32(tls_context.Edx);
    break;
  case lldb_edi_i386:
    reg_value.SetUInt32(tls_context.Edi);
    break;
  case lldb_esi_i386:
    reg_value.SetUInt32(tls_context.Esi);
    break;
  case lldb_ebp_i386:
    reg_value.SetUInt32(tls_context.Ebp);
    break;
  case lldb_esp_i386:
    reg_value.SetUInt32(tls_context.Esp);
    break;
  case lldb_eip_i386:
    reg_value.SetUInt32(tls_context.Eip);
    break;
  case lldb_eflags_i386:
    reg_value.SetUInt32(tls_context.EFlags);
    break;
  case lldb_cs_i386:
    reg_value.SetUInt32(tls_context.SegCs);
    break;
  case lldb_fs_i386:
    reg_value.SetUInt32(tls_context.SegFs);
    break;
  case lldb_gs_i386:
    reg_value.SetUInt32(tls_context.SegGs);
    break;
  case lldb_ss_i386:
    reg_value.SetUInt32(tls_context.SegSs);
    break;
  case lldb_ds_i386:
    reg_value.SetUInt32(tls_context.SegDs);
    break;
  case lldb_es_i386:
    reg_value.SetUInt32(tls_context.SegEs);
    break;
  }

  return error;
}

Status
NativeRegisterContextWindows_WoW64::GPRWrite(const uint32_t reg,
                                             const RegisterValue &reg_value) {
  ::WOW64_CONTEXT tls_context;
  auto thread_handle = GetThreadHandle();
  Status error = GetWoW64ThreadContextHelper(thread_handle, &tls_context);
  if (error.Fail())
    return error;

  switch (reg) {
  case lldb_eax_i386:
    tls_context.Eax = reg_value.GetAsUInt32();
    break;
  case lldb_ebx_i386:
    tls_context.Ebx = reg_value.GetAsUInt32();
    break;
  case lldb_ecx_i386:
    tls_context.Ecx = reg_value.GetAsUInt32();
    break;
  case lldb_edx_i386:
    tls_context.Edx = reg_value.GetAsUInt32();
    break;
  case lldb_edi_i386:
    tls_context.Edi = reg_value.GetAsUInt32();
    break;
  case lldb_esi_i386:
    tls_context.Esi = reg_value.GetAsUInt32();
    break;
  case lldb_ebp_i386:
    tls_context.Ebp = reg_value.GetAsUInt32();
    break;
  case lldb_esp_i386:
    tls_context.Esp = reg_value.GetAsUInt32();
    break;
  case lldb_eip_i386:
    tls_context.Eip = reg_value.GetAsUInt32();
    break;
  case lldb_eflags_i386:
    tls_context.EFlags = reg_value.GetAsUInt32();
    break;
  case lldb_cs_i386:
    tls_context.SegCs = reg_value.GetAsUInt32();
    break;
  case lldb_fs_i386:
    tls_context.SegFs = reg_value.GetAsUInt32();
    break;
  case lldb_gs_i386:
    tls_context.SegGs = reg_value.GetAsUInt32();
    break;
  case lldb_ss_i386:
    tls_context.SegSs = reg_value.GetAsUInt32();
    break;
  case lldb_ds_i386:
    tls_context.SegDs = reg_value.GetAsUInt32();
    break;
  case lldb_es_i386:
    tls_context.SegEs = reg_value.GetAsUInt32();
    break;
  }

  return SetWoW64ThreadContextHelper(thread_handle, &tls_context);
}

Status
NativeRegisterContextWindows_WoW64::ReadRegister(const RegisterInfo *reg_info,
                                                 RegisterValue &reg_value) {
  Status error;
  if (!reg_info) {
    error.SetErrorString("reg_info NULL");
    return error;
  }

  const uint32_t reg = reg_info->kinds[lldb::eRegisterKindLLDB];
  if (reg == LLDB_INVALID_REGNUM) {
    // This is likely an internal register for lldb use only and should not be
    // directly queried.
    error.SetErrorStringWithFormat("register \"%s\" is an internal-only lldb "
                                   "register, cannot read directly",
                                   reg_info->name);
    return error;
  }

  if (IsGPR(reg))
    return GPRRead(reg, reg_value);

  return Status("unimplemented");
}

Status NativeRegisterContextWindows_WoW64::WriteRegister(
    const RegisterInfo *reg_info, const RegisterValue &reg_value) {
  Status error;

  if (!reg_info) {
    error.SetErrorString("reg_info NULL");
    return error;
  }

  const uint32_t reg = reg_info->kinds[lldb::eRegisterKindLLDB];
  if (reg == LLDB_INVALID_REGNUM) {
    // This is likely an internal register for lldb use only and should not be
    // directly queried.
    error.SetErrorStringWithFormat("register \"%s\" is an internal-only lldb "
                                   "register, cannot read directly",
                                   reg_info->name);
    return error;
  }

  if (IsGPR(reg))
    return GPRWrite(reg, reg_value);

  return Status("unimplemented");
}

Status NativeRegisterContextWindows_WoW64::ReadAllRegisterValues(
    lldb::DataBufferSP &data_sp) {
  const size_t data_size = REG_CONTEXT_SIZE;
  data_sp = std::make_shared<DataBufferHeap>(data_size, 0);
  ::WOW64_CONTEXT tls_context;
  Status error = GetWoW64ThreadContextHelper(GetThreadHandle(), &tls_context);
  if (error.Fail())
    return error;

  uint8_t *dst = data_sp->GetBytes();
  ::memcpy(dst, &tls_context, data_size);
  return error;
}

Status NativeRegisterContextWindows_WoW64::WriteAllRegisterValues(
    const lldb::DataBufferSP &data_sp) {
  Status error;
  const size_t data_size = REG_CONTEXT_SIZE;
  if (!data_sp) {
    error.SetErrorStringWithFormat(
        "NativeRegisterContextWindows_WoW64::%s invalid data_sp provided",
        __FUNCTION__);
    return error;
  }

  if (data_sp->GetByteSize() != data_size) {
    error.SetErrorStringWithFormatv(
        "data_sp contained mismatched data size, expected {0}, actual {1}",
        data_size, data_sp->GetByteSize());
    return error;
  }

  ::WOW64_CONTEXT tls_context;
  memcpy(&tls_context, data_sp->GetBytes(), data_size);
  return SetWoW64ThreadContextHelper(GetThreadHandle(), &tls_context);
}

Status NativeRegisterContextWindows_WoW64::IsWatchpointHit(uint32_t wp_index,
                                                           bool &is_hit) {
  return Status("unimplemented");
}

Status NativeRegisterContextWindows_WoW64::GetWatchpointHitIndex(
    uint32_t &wp_index, lldb::addr_t trap_addr) {
  return Status("unimplemented");
}

Status NativeRegisterContextWindows_WoW64::IsWatchpointVacant(uint32_t wp_index,
                                                              bool &is_vacant) {
  return Status("unimplemented");
}

Status NativeRegisterContextWindows_WoW64::SetHardwareWatchpointWithIndex(
    lldb::addr_t addr, size_t size, uint32_t watch_flags, uint32_t wp_index) {
  return Status("unimplemented");
}

bool NativeRegisterContextWindows_WoW64::ClearHardwareWatchpoint(
    uint32_t wp_index) {
  return false;
}

Status NativeRegisterContextWindows_WoW64::ClearAllHardwareWatchpoints() {
  return Status("unimplemented");
}

uint32_t NativeRegisterContextWindows_WoW64::SetHardwareWatchpoint(
    lldb::addr_t addr, size_t size, uint32_t watch_flags) {
  return LLDB_INVALID_INDEX32;
}

lldb::addr_t
NativeRegisterContextWindows_WoW64::GetWatchpointAddress(uint32_t wp_index) {
  return LLDB_INVALID_ADDRESS;
}

uint32_t NativeRegisterContextWindows_WoW64::NumSupportedHardwareWatchpoints() {
  // Not implemented
  return 0;
}

#endif // defined(_WIN64)