xref: /llvm-project-15.0.7/lldb/source/Plugins/Process/Linux/NativeRegisterContextLinux_arm64.cpp (revision bf9a7730)

//===-- NativeRegisterContextLinux_arm64.cpp --------------------*- C++ -*-===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//

#if defined(__arm64__) || defined(__aarch64__)

#include "NativeRegisterContextLinux_arm.h"
#include "NativeRegisterContextLinux_arm64.h"

// C Includes
// C++ Includes

// Other libraries and framework includes
#include "lldb/Core/DataBufferHeap.h"
#include "lldb/Core/Log.h"
#include "lldb/Core/RegisterValue.h"
#include "lldb/Host/common/NativeProcessProtocol.h"
#include "lldb/Utility/Error.h"

#include "Plugins/Process/Linux/NativeProcessLinux.h"
#include "Plugins/Process/Linux/Procfs.h"
#include "Plugins/Process/POSIX/ProcessPOSIXLog.h"
#include "Plugins/Process/Utility/RegisterInfoPOSIX_arm64.h"

// System includes - They have to be included after framework includes because
// they define some
// macros which collide with variable names in other modules
#include <sys/socket.h>
// NT_PRSTATUS and NT_FPREGSET definition
#include <elf.h>
// user_hwdebug_state definition
#include <asm/ptrace.h>

#define REG_CONTEXT_SIZE (GetGPRSize() + GetFPRSize())

using namespace lldb;
using namespace lldb_private;
using namespace lldb_private::process_linux;

// ARM64 general purpose registers.
static const uint32_t g_gpr_regnums_arm64[] = {
    gpr_x0_arm64,       gpr_x1_arm64,   gpr_x2_arm64,  gpr_x3_arm64,
    gpr_x4_arm64,       gpr_x5_arm64,   gpr_x6_arm64,  gpr_x7_arm64,
    gpr_x8_arm64,       gpr_x9_arm64,   gpr_x10_arm64, gpr_x11_arm64,
    gpr_x12_arm64,      gpr_x13_arm64,  gpr_x14_arm64, gpr_x15_arm64,
    gpr_x16_arm64,      gpr_x17_arm64,  gpr_x18_arm64, gpr_x19_arm64,
    gpr_x20_arm64,      gpr_x21_arm64,  gpr_x22_arm64, gpr_x23_arm64,
    gpr_x24_arm64,      gpr_x25_arm64,  gpr_x26_arm64, gpr_x27_arm64,
    gpr_x28_arm64,      gpr_fp_arm64,   gpr_lr_arm64,  gpr_sp_arm64,
    gpr_pc_arm64,       gpr_cpsr_arm64, gpr_w0_arm64,  gpr_w1_arm64,
    gpr_w2_arm64,       gpr_w3_arm64,   gpr_w4_arm64,  gpr_w5_arm64,
    gpr_w6_arm64,       gpr_w7_arm64,   gpr_w8_arm64,  gpr_w9_arm64,
    gpr_w10_arm64,      gpr_w11_arm64,  gpr_w12_arm64, gpr_w13_arm64,
    gpr_w14_arm64,      gpr_w15_arm64,  gpr_w16_arm64, gpr_w17_arm64,
    gpr_w18_arm64,      gpr_w19_arm64,  gpr_w20_arm64, gpr_w21_arm64,
    gpr_w22_arm64,      gpr_w23_arm64,  gpr_w24_arm64, gpr_w25_arm64,
    gpr_w26_arm64,      gpr_w27_arm64,  gpr_w28_arm64,
    LLDB_INVALID_REGNUM // register sets need to end with this flag
};
static_assert(((sizeof g_gpr_regnums_arm64 / sizeof g_gpr_regnums_arm64[0]) -
               1) == k_num_gpr_registers_arm64,
              "g_gpr_regnums_arm64 has wrong number of register infos");

// ARM64 floating point registers.
static const uint32_t g_fpu_regnums_arm64[] = {
    fpu_v0_arm64,       fpu_v1_arm64,   fpu_v2_arm64,  fpu_v3_arm64,
    fpu_v4_arm64,       fpu_v5_arm64,   fpu_v6_arm64,  fpu_v7_arm64,
    fpu_v8_arm64,       fpu_v9_arm64,   fpu_v10_arm64, fpu_v11_arm64,
    fpu_v12_arm64,      fpu_v13_arm64,  fpu_v14_arm64, fpu_v15_arm64,
    fpu_v16_arm64,      fpu_v17_arm64,  fpu_v18_arm64, fpu_v19_arm64,
    fpu_v20_arm64,      fpu_v21_arm64,  fpu_v22_arm64, fpu_v23_arm64,
    fpu_v24_arm64,      fpu_v25_arm64,  fpu_v26_arm64, fpu_v27_arm64,
    fpu_v28_arm64,      fpu_v29_arm64,  fpu_v30_arm64, fpu_v31_arm64,
    fpu_s0_arm64,       fpu_s1_arm64,   fpu_s2_arm64,  fpu_s3_arm64,
    fpu_s4_arm64,       fpu_s5_arm64,   fpu_s6_arm64,  fpu_s7_arm64,
    fpu_s8_arm64,       fpu_s9_arm64,   fpu_s10_arm64, fpu_s11_arm64,
    fpu_s12_arm64,      fpu_s13_arm64,  fpu_s14_arm64, fpu_s15_arm64,
    fpu_s16_arm64,      fpu_s17_arm64,  fpu_s18_arm64, fpu_s19_arm64,
    fpu_s20_arm64,      fpu_s21_arm64,  fpu_s22_arm64, fpu_s23_arm64,
    fpu_s24_arm64,      fpu_s25_arm64,  fpu_s26_arm64, fpu_s27_arm64,
    fpu_s28_arm64,      fpu_s29_arm64,  fpu_s30_arm64, fpu_s31_arm64,

    fpu_d0_arm64,       fpu_d1_arm64,   fpu_d2_arm64,  fpu_d3_arm64,
    fpu_d4_arm64,       fpu_d5_arm64,   fpu_d6_arm64,  fpu_d7_arm64,
    fpu_d8_arm64,       fpu_d9_arm64,   fpu_d10_arm64, fpu_d11_arm64,
    fpu_d12_arm64,      fpu_d13_arm64,  fpu_d14_arm64, fpu_d15_arm64,
    fpu_d16_arm64,      fpu_d17_arm64,  fpu_d18_arm64, fpu_d19_arm64,
    fpu_d20_arm64,      fpu_d21_arm64,  fpu_d22_arm64, fpu_d23_arm64,
    fpu_d24_arm64,      fpu_d25_arm64,  fpu_d26_arm64, fpu_d27_arm64,
    fpu_d28_arm64,      fpu_d29_arm64,  fpu_d30_arm64, fpu_d31_arm64,
    fpu_fpsr_arm64,     fpu_fpcr_arm64,
    LLDB_INVALID_REGNUM // register sets need to end with this flag
};
static_assert(((sizeof g_fpu_regnums_arm64 / sizeof g_fpu_regnums_arm64[0]) -
               1) == k_num_fpr_registers_arm64,
              "g_fpu_regnums_arm64 has wrong number of register infos");

namespace {
// Number of register sets provided by this context.
enum { k_num_register_sets = 2 };
}

// Register sets for ARM64.
static const RegisterSet g_reg_sets_arm64[k_num_register_sets] = {
    {"General Purpose Registers", "gpr", k_num_gpr_registers_arm64,
     g_gpr_regnums_arm64},
    {"Floating Point Registers", "fpu", k_num_fpr_registers_arm64,
     g_fpu_regnums_arm64}};

NativeRegisterContextLinux *
NativeRegisterContextLinux::CreateHostNativeRegisterContextLinux(
    const ArchSpec &target_arch, NativeThreadProtocol &native_thread,
    uint32_t concrete_frame_idx) {
  Log *log = ProcessPOSIXLog::GetLogIfAllCategoriesSet(POSIX_LOG_REGISTERS);
  switch (target_arch.GetMachine()) {
  case llvm::Triple::arm:
    return new NativeRegisterContextLinux_arm(target_arch, native_thread,
                                              concrete_frame_idx);
  case llvm::Triple::aarch64:
    return new NativeRegisterContextLinux_arm64(target_arch, native_thread,
                                                concrete_frame_idx);
  default:
    if (log)
      log->Printf("NativeRegisterContextLinux::%s() have no register context "
                  "for architecture: %s\n",
                  __FUNCTION__,
                  target_arch.GetTriple().getArchName().str().c_str());
    return nullptr;
  }
}

NativeRegisterContextLinux_arm64::NativeRegisterContextLinux_arm64(
    const ArchSpec &target_arch, NativeThreadProtocol &native_thread,
    uint32_t concrete_frame_idx)
    : NativeRegisterContextLinux(native_thread, concrete_frame_idx,
                                 new RegisterInfoPOSIX_arm64(target_arch)) {
  switch (target_arch.GetMachine()) {
  case llvm::Triple::aarch64:
    m_reg_info.num_registers = k_num_registers_arm64;
    m_reg_info.num_gpr_registers = k_num_gpr_registers_arm64;
    m_reg_info.num_fpr_registers = k_num_fpr_registers_arm64;
    m_reg_info.last_gpr = k_last_gpr_arm64;
    m_reg_info.first_fpr = k_first_fpr_arm64;
    m_reg_info.last_fpr = k_last_fpr_arm64;
    m_reg_info.first_fpr_v = fpu_v0_arm64;
    m_reg_info.last_fpr_v = fpu_v31_arm64;
    m_reg_info.gpr_flags = gpr_cpsr_arm64;
    break;
  default:
    assert(false && "Unhandled target architecture.");
    break;
  }

  ::memset(&m_fpr, 0, sizeof(m_fpr));
  ::memset(&m_gpr_arm64, 0, sizeof(m_gpr_arm64));
  ::memset(&m_hwp_regs, 0, sizeof(m_hwp_regs));

  // 16 is just a maximum value, query hardware for actual watchpoint count
  m_max_hwp_supported = 16;
  m_max_hbp_supported = 16;
  m_refresh_hwdebug_info = true;
}

uint32_t NativeRegisterContextLinux_arm64::GetRegisterSetCount() const {
  return k_num_register_sets;
}

const RegisterSet *
NativeRegisterContextLinux_arm64::GetRegisterSet(uint32_t set_index) const {
  if (set_index < k_num_register_sets)
    return &g_reg_sets_arm64[set_index];

  return nullptr;
}

uint32_t NativeRegisterContextLinux_arm64::GetUserRegisterCount() const {
  uint32_t count = 0;
  for (uint32_t set_index = 0; set_index < k_num_register_sets; ++set_index)
    count += g_reg_sets_arm64[set_index].num_registers;
  return count;
}

Error NativeRegisterContextLinux_arm64::ReadRegister(
    const RegisterInfo *reg_info, RegisterValue &reg_value) {
  Error error;

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

  const uint32_t reg = reg_info->kinds[lldb::eRegisterKindLLDB];

  if (IsFPR(reg)) {
    error = ReadFPR();
    if (error.Fail())
      return error;
  } else {
    uint32_t full_reg = reg;
    bool is_subreg = reg_info->invalidate_regs &&
                     (reg_info->invalidate_regs[0] != LLDB_INVALID_REGNUM);

    if (is_subreg) {
      // Read the full aligned 64-bit register.
      full_reg = reg_info->invalidate_regs[0];
    }

    error = ReadRegisterRaw(full_reg, reg_value);

    if (error.Success()) {
      // If our read was not aligned (for ah,bh,ch,dh), shift our returned value
      // one byte to the right.
      if (is_subreg && (reg_info->byte_offset & 0x1))
        reg_value.SetUInt64(reg_value.GetAsUInt64() >> 8);

      // If our return byte size was greater than the return value reg size,
      // then
      // use the type specified by reg_info rather than the uint64_t default
      if (reg_value.GetByteSize() > reg_info->byte_size)
        reg_value.SetType(reg_info);
    }
    return error;
  }

  // Get pointer to m_fpr variable and set the data from it.
  uint32_t fpr_offset = CalculateFprOffset(reg_info);
  assert(fpr_offset < sizeof m_fpr);
  uint8_t *src = (uint8_t *)&m_fpr + fpr_offset;
  reg_value.SetFromMemoryData(reg_info, src, reg_info->byte_size,
                              eByteOrderLittle, error);

  return error;
}

Error NativeRegisterContextLinux_arm64::WriteRegister(
    const RegisterInfo *reg_info, const RegisterValue &reg_value) {
  if (!reg_info)
    return Error("reg_info NULL");

  const uint32_t reg_index = reg_info->kinds[lldb::eRegisterKindLLDB];
  if (reg_index == LLDB_INVALID_REGNUM)
    return Error("no lldb regnum for %s", reg_info && reg_info->name
                                              ? reg_info->name
                                              : "<unknown register>");

  if (IsGPR(reg_index))
    return WriteRegisterRaw(reg_index, reg_value);

  if (IsFPR(reg_index)) {
    // Get pointer to m_fpr variable and set the data to it.
    uint32_t fpr_offset = CalculateFprOffset(reg_info);
    assert(fpr_offset < sizeof m_fpr);
    uint8_t *dst = (uint8_t *)&m_fpr + fpr_offset;
    switch (reg_info->byte_size) {
    case 2:
      *(uint16_t *)dst = reg_value.GetAsUInt16();
      break;
    case 4:
      *(uint32_t *)dst = reg_value.GetAsUInt32();
      break;
    case 8:
      *(uint64_t *)dst = reg_value.GetAsUInt64();
      break;
    default:
      assert(false && "Unhandled data size.");
      return Error("unhandled register data size %" PRIu32,
                   reg_info->byte_size);
    }

    Error error = WriteFPR();
    if (error.Fail())
      return error;

    return Error();
  }

  return Error("failed - register wasn't recognized to be a GPR or an FPR, "
               "write strategy unknown");
}

Error NativeRegisterContextLinux_arm64::ReadAllRegisterValues(
    lldb::DataBufferSP &data_sp) {
  Error error;

  data_sp.reset(new DataBufferHeap(REG_CONTEXT_SIZE, 0));
  if (!data_sp)
    return Error("failed to allocate DataBufferHeap instance of size %" PRIu64,
                 REG_CONTEXT_SIZE);

  error = ReadGPR();
  if (error.Fail())
    return error;

  error = ReadFPR();
  if (error.Fail())
    return error;

  uint8_t *dst = data_sp->GetBytes();
  if (dst == nullptr) {
    error.SetErrorStringWithFormat("DataBufferHeap instance of size %" PRIu64
                                   " returned a null pointer",
                                   REG_CONTEXT_SIZE);
    return error;
  }

  ::memcpy(dst, &m_gpr_arm64, GetGPRSize());
  dst += GetGPRSize();
  ::memcpy(dst, &m_fpr, sizeof(m_fpr));

  return error;
}

Error NativeRegisterContextLinux_arm64::WriteAllRegisterValues(
    const lldb::DataBufferSP &data_sp) {
  Error error;

  if (!data_sp) {
    error.SetErrorStringWithFormat(
        "NativeRegisterContextLinux_x86_64::%s invalid data_sp provided",
        __FUNCTION__);
    return error;
  }

  if (data_sp->GetByteSize() != REG_CONTEXT_SIZE) {
    error.SetErrorStringWithFormat(
        "NativeRegisterContextLinux_x86_64::%s data_sp contained mismatched "
        "data size, expected %" PRIu64 ", actual %" PRIu64,
        __FUNCTION__, REG_CONTEXT_SIZE, data_sp->GetByteSize());
    return error;
  }

  uint8_t *src = data_sp->GetBytes();
  if (src == nullptr) {
    error.SetErrorStringWithFormat("NativeRegisterContextLinux_x86_64::%s "
                                   "DataBuffer::GetBytes() returned a null "
                                   "pointer",
                                   __FUNCTION__);
    return error;
  }
  ::memcpy(&m_gpr_arm64, src, GetRegisterInfoInterface().GetGPRSize());

  error = WriteGPR();
  if (error.Fail())
    return error;

  src += GetRegisterInfoInterface().GetGPRSize();
  ::memcpy(&m_fpr, src, sizeof(m_fpr));

  error = WriteFPR();
  if (error.Fail())
    return error;

  return error;
}

bool NativeRegisterContextLinux_arm64::IsGPR(unsigned reg) const {
  return reg <= m_reg_info.last_gpr; // GPR's come first.
}

bool NativeRegisterContextLinux_arm64::IsFPR(unsigned reg) const {
  return (m_reg_info.first_fpr <= reg && reg <= m_reg_info.last_fpr);
}

uint32_t
NativeRegisterContextLinux_arm64::SetHardwareBreakpoint(lldb::addr_t addr,
                                                        size_t size) {
  Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_WATCHPOINTS));

  if (log)
    log->Printf("NativeRegisterContextLinux_arm64::%s()", __FUNCTION__);

  Error error;

  // Read hardware breakpoint and watchpoint information.
  error = ReadHardwareDebugInfo();

  if (error.Fail())
    return LLDB_INVALID_INDEX32;

  uint32_t control_value = 0, bp_index = 0;

  // Check if size has a valid hardware breakpoint length.
  if (size != 4)
    return LLDB_INVALID_INDEX32; // Invalid size for a AArch64 hardware
                                 // breakpoint

  // Check 4-byte alignment for hardware breakpoint target address.
  if (addr & 0x03)
    return LLDB_INVALID_INDEX32; // Invalid address, should be 4-byte aligned.

  // Setup control value
  control_value = 0;
  control_value |= ((1 << size) - 1) << 5;
  control_value |= (2 << 1) | 1;

  // Iterate over stored hardware breakpoints
  // Find a free bp_index or update reference count if duplicate.
  bp_index = LLDB_INVALID_INDEX32;
  for (uint32_t i = 0; i < m_max_hbp_supported; i++) {
    if ((m_hbr_regs[i].control & 1) == 0) {
      bp_index = i; // Mark last free slot
    } else if (m_hbr_regs[i].address == addr &&
               m_hbr_regs[i].control == control_value) {
      bp_index = i; // Mark duplicate index
      break;        // Stop searching here
    }
  }

  if (bp_index == LLDB_INVALID_INDEX32)
    return LLDB_INVALID_INDEX32;

  // Add new or update existing breakpoint
  if ((m_hbr_regs[bp_index].control & 1) == 0) {
    m_hbr_regs[bp_index].address = addr;
    m_hbr_regs[bp_index].control = control_value;
    m_hbr_regs[bp_index].refcount = 1;

    // PTRACE call to set corresponding hardware breakpoint register.
    error = WriteHardwareDebugRegs(eDREGTypeBREAK);

    if (error.Fail()) {
      m_hbr_regs[bp_index].address = 0;
      m_hbr_regs[bp_index].control &= ~1;
      m_hbr_regs[bp_index].refcount = 0;

      return LLDB_INVALID_INDEX32;
    }
  } else
    m_hbr_regs[bp_index].refcount++;

  return bp_index;
}

bool NativeRegisterContextLinux_arm64::ClearHardwareBreakpoint(
    uint32_t hw_idx) {
  Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_WATCHPOINTS));

  if (log)
    log->Printf("NativeRegisterContextLinux_arm64::%s()", __FUNCTION__);

  Error error;

  // Read hardware breakpoint and watchpoint information.
  error = ReadHardwareDebugInfo();

  if (error.Fail())
    return false;

  if (hw_idx >= m_max_hbp_supported)
    return false;

  // Update reference count if multiple references.
  if (m_hbr_regs[hw_idx].refcount > 1) {
    m_hbr_regs[hw_idx].refcount--;
    return true;
  } else if (m_hbr_regs[hw_idx].refcount == 1) {
    // Create a backup we can revert to in case of failure.
    lldb::addr_t tempAddr = m_hbr_regs[hw_idx].address;
    uint32_t tempControl = m_hbr_regs[hw_idx].control;
    uint32_t tempRefCount = m_hbr_regs[hw_idx].refcount;

    m_hbr_regs[hw_idx].control &= ~1;
    m_hbr_regs[hw_idx].address = 0;
    m_hbr_regs[hw_idx].refcount = 0;

    // PTRACE call to clear corresponding hardware breakpoint register.
    WriteHardwareDebugRegs(eDREGTypeBREAK);

    if (error.Fail()) {
      m_hbr_regs[hw_idx].control = tempControl;
      m_hbr_regs[hw_idx].address = tempAddr;
      m_hbr_regs[hw_idx].refcount = tempRefCount;

      return false;
    }

    return true;
  }

  return false;
}

uint32_t NativeRegisterContextLinux_arm64::NumSupportedHardwareWatchpoints() {
  Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_WATCHPOINTS));

  if (log)
    log->Printf("NativeRegisterContextLinux_arm64::%s()", __FUNCTION__);

  Error error;

  // Read hardware breakpoint and watchpoint information.
  error = ReadHardwareDebugInfo();

  if (error.Fail())
    return 0;

  return m_max_hwp_supported;
}

uint32_t NativeRegisterContextLinux_arm64::SetHardwareWatchpoint(
    lldb::addr_t addr, size_t size, uint32_t watch_flags) {
  Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_WATCHPOINTS));

  if (log)
    log->Printf("NativeRegisterContextLinux_arm64::%s()", __FUNCTION__);

  Error error;

  // Read hardware breakpoint and watchpoint information.
  error = ReadHardwareDebugInfo();

  if (error.Fail())
    return LLDB_INVALID_INDEX32;

  uint32_t control_value = 0, wp_index = 0;
  lldb::addr_t real_addr = addr;

  // Check if we are setting watchpoint other than read/write/access
  // Also update watchpoint flag to match AArch64 write-read bit configuration.
  switch (watch_flags) {
  case 1:
    watch_flags = 2;
    break;
  case 2:
    watch_flags = 1;
    break;
  case 3:
    break;
  default:
    return LLDB_INVALID_INDEX32;
  }

  // Check if size has a valid hardware watchpoint length.
  if (size != 1 && size != 2 && size != 4 && size != 8)
    return LLDB_INVALID_INDEX32;

  // Check 8-byte alignment for hardware watchpoint target address.
  // Below is a hack to recalculate address and size in order to
  // make sure we can watch non 8-byte alligned addresses as well.
  if (addr & 0x07) {
    uint8_t watch_mask = (addr & 0x07) + size;

    if (watch_mask > 0x08)
      return LLDB_INVALID_INDEX32;
    else if (watch_mask <= 0x02)
      size = 2;
    else if (watch_mask <= 0x04)
      size = 4;
    else
      size = 8;

    addr = addr & (~0x07);
  }

  // Setup control value
  control_value = watch_flags << 3;
  control_value |= ((1 << size) - 1) << 5;
  control_value |= (2 << 1) | 1;

  // Iterate over stored watchpoints and find a free wp_index
  wp_index = LLDB_INVALID_INDEX32;
  for (uint32_t i = 0; i < m_max_hwp_supported; i++) {
    if ((m_hwp_regs[i].control & 1) == 0) {
      wp_index = i; // Mark last free slot
    } else if (m_hwp_regs[i].address == addr) {
      return LLDB_INVALID_INDEX32; // We do not support duplicate watchpoints.
    }
  }

  if (wp_index == LLDB_INVALID_INDEX32)
    return LLDB_INVALID_INDEX32;

  // Update watchpoint in local cache
  m_hwp_regs[wp_index].real_addr = real_addr;
  m_hwp_regs[wp_index].address = addr;
  m_hwp_regs[wp_index].control = control_value;

  // PTRACE call to set corresponding watchpoint register.
  error = WriteHardwareDebugRegs(eDREGTypeWATCH);

  if (error.Fail()) {
    m_hwp_regs[wp_index].address = 0;
    m_hwp_regs[wp_index].control &= ~1;

    return LLDB_INVALID_INDEX32;
  }

  return wp_index;
}

bool NativeRegisterContextLinux_arm64::ClearHardwareWatchpoint(
    uint32_t wp_index) {
  Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_WATCHPOINTS));

  if (log)
    log->Printf("NativeRegisterContextLinux_arm64::%s()", __FUNCTION__);

  Error error;

  // Read hardware breakpoint and watchpoint information.
  error = ReadHardwareDebugInfo();

  if (error.Fail())
    return false;

  if (wp_index >= m_max_hwp_supported)
    return false;

  // Create a backup we can revert to in case of failure.
  lldb::addr_t tempAddr = m_hwp_regs[wp_index].address;
  uint32_t tempControl = m_hwp_regs[wp_index].control;

  // Update watchpoint in local cache
  m_hwp_regs[wp_index].control &= ~1;
  m_hwp_regs[wp_index].address = 0;

  // Ptrace call to update hardware debug registers
  error = WriteHardwareDebugRegs(eDREGTypeWATCH);

  if (error.Fail()) {
    m_hwp_regs[wp_index].control = tempControl;
    m_hwp_regs[wp_index].address = tempAddr;

    return false;
  }

  return true;
}

Error NativeRegisterContextLinux_arm64::ClearAllHardwareWatchpoints() {
  Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_WATCHPOINTS));

  if (log)
    log->Printf("NativeRegisterContextLinux_arm64::%s()", __FUNCTION__);

  Error error;

  // Read hardware breakpoint and watchpoint information.
  error = ReadHardwareDebugInfo();

  if (error.Fail())
    return error;

  lldb::addr_t tempAddr = 0;
  uint32_t tempControl = 0, tempRefCount = 0;

  for (uint32_t i = 0; i < m_max_hwp_supported; i++) {
    if (m_hwp_regs[i].control & 0x01) {
      // Create a backup we can revert to in case of failure.
      tempAddr = m_hwp_regs[i].address;
      tempControl = m_hwp_regs[i].control;

      // Clear watchpoints in local cache
      m_hwp_regs[i].control &= ~1;
      m_hwp_regs[i].address = 0;

      // Ptrace call to update hardware debug registers
      error = WriteHardwareDebugRegs(eDREGTypeWATCH);

      if (error.Fail()) {
        m_hwp_regs[i].control = tempControl;
        m_hwp_regs[i].address = tempAddr;

        return error;
      }
    }
  }

  return Error();
}

uint32_t
NativeRegisterContextLinux_arm64::GetWatchpointSize(uint32_t wp_index) {
  Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_WATCHPOINTS));

  if (log)
    log->Printf("NativeRegisterContextLinux_arm64::%s()", __FUNCTION__);
  switch ((m_hwp_regs[wp_index].control >> 5) & 0xff) {
  case 0x01:
    return 1;
  case 0x03:
    return 2;
  case 0x0f:
    return 4;
  case 0xff:
    return 8;
  default:
    return 0;
  }
}
bool NativeRegisterContextLinux_arm64::WatchpointIsEnabled(uint32_t wp_index) {
  Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_WATCHPOINTS));

  if (log)
    log->Printf("NativeRegisterContextLinux_arm64::%s()", __FUNCTION__);

  if ((m_hwp_regs[wp_index].control & 0x1) == 0x1)
    return true;
  else
    return false;
}

Error NativeRegisterContextLinux_arm64::GetWatchpointHitIndex(
    uint32_t &wp_index, lldb::addr_t trap_addr) {
  Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_WATCHPOINTS));

  if (log)
    log->Printf("NativeRegisterContextLinux_arm64::%s()", __FUNCTION__);

  uint32_t watch_size;
  lldb::addr_t watch_addr;

  for (wp_index = 0; wp_index < m_max_hwp_supported; ++wp_index) {
    watch_size = GetWatchpointSize(wp_index);
    watch_addr = m_hwp_regs[wp_index].address;

    if (WatchpointIsEnabled(wp_index) && trap_addr >= watch_addr &&
        trap_addr < watch_addr + watch_size) {
      m_hwp_regs[wp_index].hit_addr = trap_addr;
      return Error();
    }
  }

  wp_index = LLDB_INVALID_INDEX32;
  return Error();
}

lldb::addr_t
NativeRegisterContextLinux_arm64::GetWatchpointAddress(uint32_t wp_index) {
  Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_WATCHPOINTS));

  if (log)
    log->Printf("NativeRegisterContextLinux_arm64::%s()", __FUNCTION__);

  if (wp_index >= m_max_hwp_supported)
    return LLDB_INVALID_ADDRESS;

  if (WatchpointIsEnabled(wp_index))
    return m_hwp_regs[wp_index].real_addr;
  else
    return LLDB_INVALID_ADDRESS;
}

lldb::addr_t
NativeRegisterContextLinux_arm64::GetWatchpointHitAddress(uint32_t wp_index) {
  Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_WATCHPOINTS));

  if (log)
    log->Printf("NativeRegisterContextLinux_arm64::%s()", __FUNCTION__);

  if (wp_index >= m_max_hwp_supported)
    return LLDB_INVALID_ADDRESS;

  if (WatchpointIsEnabled(wp_index))
    return m_hwp_regs[wp_index].hit_addr;
  else
    return LLDB_INVALID_ADDRESS;
}

Error NativeRegisterContextLinux_arm64::ReadHardwareDebugInfo() {
  if (!m_refresh_hwdebug_info) {
    return Error();
  }

  ::pid_t tid = m_thread.GetID();

  int regset = NT_ARM_HW_WATCH;
  struct iovec ioVec;
  struct user_hwdebug_state dreg_state;
  Error error;

  ioVec.iov_base = &dreg_state;
  ioVec.iov_len = sizeof(dreg_state);
  error = NativeProcessLinux::PtraceWrapper(PTRACE_GETREGSET, tid, &regset,
                                            &ioVec, ioVec.iov_len);

  if (error.Fail())
    return error;

  m_max_hwp_supported = dreg_state.dbg_info & 0xff;

  regset = NT_ARM_HW_BREAK;
  error = NativeProcessLinux::PtraceWrapper(PTRACE_GETREGSET, tid, &regset,
                                            &ioVec, ioVec.iov_len);

  if (error.Fail())
    return error;

  m_max_hbp_supported = dreg_state.dbg_info & 0xff;
  m_refresh_hwdebug_info = false;

  return error;
}

Error NativeRegisterContextLinux_arm64::WriteHardwareDebugRegs(int hwbType) {
  struct iovec ioVec;
  struct user_hwdebug_state dreg_state;
  Error error;

  memset(&dreg_state, 0, sizeof(dreg_state));
  ioVec.iov_base = &dreg_state;

  if (hwbType == eDREGTypeWATCH) {
    hwbType = NT_ARM_HW_WATCH;
    ioVec.iov_len = sizeof(dreg_state.dbg_info) + sizeof(dreg_state.pad) +
                    (sizeof(dreg_state.dbg_regs[0]) * m_max_hwp_supported);

    for (uint32_t i = 0; i < m_max_hwp_supported; i++) {
      dreg_state.dbg_regs[i].addr = m_hwp_regs[i].address;
      dreg_state.dbg_regs[i].ctrl = m_hwp_regs[i].control;
    }
  } else {
    hwbType = NT_ARM_HW_BREAK;
    ioVec.iov_len = sizeof(dreg_state.dbg_info) + sizeof(dreg_state.pad) +
                    (sizeof(dreg_state.dbg_regs[0]) * m_max_hbp_supported);

    for (uint32_t i = 0; i < m_max_hbp_supported; i++) {
      dreg_state.dbg_regs[i].addr = m_hbr_regs[i].address;
      dreg_state.dbg_regs[i].ctrl = m_hbr_regs[i].control;
    }
  }

  return NativeProcessLinux::PtraceWrapper(PTRACE_SETREGSET, m_thread.GetID(),
                                           &hwbType, &ioVec, ioVec.iov_len);
}

Error NativeRegisterContextLinux_arm64::DoReadRegisterValue(
    uint32_t offset, const char *reg_name, uint32_t size,
    RegisterValue &value) {
  Error error;
  if (offset > sizeof(struct user_pt_regs)) {
    uintptr_t offset = offset - sizeof(struct user_pt_regs);
    if (offset > sizeof(struct user_fpsimd_state)) {
      error.SetErrorString("invalid offset value");
      return error;
    }
    elf_fpregset_t regs;
    int regset = NT_FPREGSET;
    struct iovec ioVec;

    ioVec.iov_base = &regs;
    ioVec.iov_len = sizeof regs;
    error = NativeProcessLinux::PtraceWrapper(
        PTRACE_GETREGSET, m_thread.GetID(), &regset, &ioVec, sizeof regs);
    if (error.Success()) {
      ArchSpec arch;
      if (m_thread.GetProcess()->GetArchitecture(arch))
        value.SetBytes((void *)(((unsigned char *)(&regs)) + offset), 16,
                       arch.GetByteOrder());
      else
        error.SetErrorString("failed to get architecture");
    }
  } else {
    elf_gregset_t regs;
    int regset = NT_PRSTATUS;
    struct iovec ioVec;

    ioVec.iov_base = &regs;
    ioVec.iov_len = sizeof regs;
    error = NativeProcessLinux::PtraceWrapper(
        PTRACE_GETREGSET, m_thread.GetID(), &regset, &ioVec, sizeof regs);
    if (error.Success()) {
      ArchSpec arch;
      if (m_thread.GetProcess()->GetArchitecture(arch))
        value.SetBytes((void *)(((unsigned char *)(regs)) + offset), 8,
                       arch.GetByteOrder());
      else
        error.SetErrorString("failed to get architecture");
    }
  }
  return error;
}

Error NativeRegisterContextLinux_arm64::DoWriteRegisterValue(
    uint32_t offset, const char *reg_name, const RegisterValue &value) {
  Error error;
  ::pid_t tid = m_thread.GetID();
  if (offset > sizeof(struct user_pt_regs)) {
    uintptr_t offset = offset - sizeof(struct user_pt_regs);
    if (offset > sizeof(struct user_fpsimd_state)) {
      error.SetErrorString("invalid offset value");
      return error;
    }
    elf_fpregset_t regs;
    int regset = NT_FPREGSET;
    struct iovec ioVec;

    ioVec.iov_base = &regs;
    ioVec.iov_len = sizeof regs;
    error = NativeProcessLinux::PtraceWrapper(PTRACE_GETREGSET, tid, &regset,
                                              &ioVec, sizeof regs);

    if (error.Success()) {
      ::memcpy((void *)(((unsigned char *)(&regs)) + offset), value.GetBytes(),
               16);
      error = NativeProcessLinux::PtraceWrapper(PTRACE_SETREGSET, tid, &regset,
                                                &ioVec, sizeof regs);
    }
  } else {
    elf_gregset_t regs;
    int regset = NT_PRSTATUS;
    struct iovec ioVec;

    ioVec.iov_base = &regs;
    ioVec.iov_len = sizeof regs;
    error = NativeProcessLinux::PtraceWrapper(PTRACE_GETREGSET, tid, &regset,
                                              &ioVec, sizeof regs);
    if (error.Success()) {
      ::memcpy((void *)(((unsigned char *)(&regs)) + offset), value.GetBytes(),
               8);
      error = NativeProcessLinux::PtraceWrapper(PTRACE_SETREGSET, tid, &regset,
                                                &ioVec, sizeof regs);
    }
  }
  return error;
}

Error NativeRegisterContextLinux_arm64::DoReadGPR(void *buf, size_t buf_size) {
  int regset = NT_PRSTATUS;
  struct iovec ioVec;
  Error error;

  ioVec.iov_base = buf;
  ioVec.iov_len = buf_size;
  return NativeProcessLinux::PtraceWrapper(PTRACE_GETREGSET, m_thread.GetID(),
                                           &regset, &ioVec, buf_size);
}

Error NativeRegisterContextLinux_arm64::DoWriteGPR(void *buf, size_t buf_size) {
  int regset = NT_PRSTATUS;
  struct iovec ioVec;
  Error error;

  ioVec.iov_base = buf;
  ioVec.iov_len = buf_size;
  return NativeProcessLinux::PtraceWrapper(PTRACE_SETREGSET, m_thread.GetID(),
                                           &regset, &ioVec, buf_size);
}

Error NativeRegisterContextLinux_arm64::DoReadFPR(void *buf, size_t buf_size) {
  int regset = NT_FPREGSET;
  struct iovec ioVec;
  Error error;

  ioVec.iov_base = buf;
  ioVec.iov_len = buf_size;
  return NativeProcessLinux::PtraceWrapper(PTRACE_GETREGSET, m_thread.GetID(),
                                           &regset, &ioVec, buf_size);
}

Error NativeRegisterContextLinux_arm64::DoWriteFPR(void *buf, size_t buf_size) {
  int regset = NT_FPREGSET;
  struct iovec ioVec;
  Error error;

  ioVec.iov_base = buf;
  ioVec.iov_len = buf_size;
  return NativeProcessLinux::PtraceWrapper(PTRACE_SETREGSET, m_thread.GetID(),
                                           &regset, &ioVec, buf_size);
}

uint32_t NativeRegisterContextLinux_arm64::CalculateFprOffset(
    const RegisterInfo *reg_info) const {
  return reg_info->byte_offset -
         GetRegisterInfoAtIndex(m_reg_info.first_fpr)->byte_offset;
}

#endif // defined (__arm64__) || defined (__aarch64__)