C++ DataExtractor::ValidOffsetForDataOfSize方法代码示例

//----------------------------------------------------------------------
// ParseDOSHeader
//----------------------------------------------------------------------
bool ObjectFilePECOFF::ParseDOSHeader(DataExtractor &data,
                                      dos_header_t &dos_header) {
  bool success = false;
  lldb::offset_t offset = 0;
  success = data.ValidOffsetForDataOfSize(0, sizeof(dos_header));

  if (success) {
    dos_header.e_magic = data.GetU16(&offset); // Magic number
    success = dos_header.e_magic == IMAGE_DOS_SIGNATURE;

    if (success) {
      dos_header.e_cblp = data.GetU16(&offset); // Bytes on last page of file
      dos_header.e_cp = data.GetU16(&offset);   // Pages in file
      dos_header.e_crlc = data.GetU16(&offset); // Relocations
      dos_header.e_cparhdr =
          data.GetU16(&offset); // Size of header in paragraphs
      dos_header.e_minalloc =
          data.GetU16(&offset); // Minimum extra paragraphs needed
      dos_header.e_maxalloc =
          data.GetU16(&offset);               // Maximum extra paragraphs needed
      dos_header.e_ss = data.GetU16(&offset); // Initial (relative) SS value
      dos_header.e_sp = data.GetU16(&offset); // Initial SP value
      dos_header.e_csum = data.GetU16(&offset); // Checksum
      dos_header.e_ip = data.GetU16(&offset);   // Initial IP value
      dos_header.e_cs = data.GetU16(&offset);   // Initial (relative) CS value
      dos_header.e_lfarlc =
          data.GetU16(&offset); // File address of relocation table
      dos_header.e_ovno = data.GetU16(&offset); // Overlay number

      dos_header.e_res[0] = data.GetU16(&offset); // Reserved words
      dos_header.e_res[1] = data.GetU16(&offset); // Reserved words
      dos_header.e_res[2] = data.GetU16(&offset); // Reserved words
      dos_header.e_res[3] = data.GetU16(&offset); // Reserved words

      dos_header.e_oemid =
          data.GetU16(&offset); // OEM identifier (for e_oeminfo)
      dos_header.e_oeminfo =
          data.GetU16(&offset); // OEM information; e_oemid specific
      dos_header.e_res2[0] = data.GetU16(&offset); // Reserved words
      dos_header.e_res2[1] = data.GetU16(&offset); // Reserved words
      dos_header.e_res2[2] = data.GetU16(&offset); // Reserved words
      dos_header.e_res2[3] = data.GetU16(&offset); // Reserved words
      dos_header.e_res2[4] = data.GetU16(&offset); // Reserved words
      dos_header.e_res2[5] = data.GetU16(&offset); // Reserved words
      dos_header.e_res2[6] = data.GetU16(&offset); // Reserved words
      dos_header.e_res2[7] = data.GetU16(&offset); // Reserved words
      dos_header.e_res2[8] = data.GetU16(&offset); // Reserved words
      dos_header.e_res2[9] = data.GetU16(&offset); // Reserved words

      dos_header.e_lfanew =
          data.GetU32(&offset); // File address of new exe header
    }
  }
  if (!success)
    memset(&dos_header, 0, sizeof(dos_header));
  return success;
}

//----------------------------------------------------------------------
// ParserCOFFHeader
//----------------------------------------------------------------------
bool ObjectFilePECOFF::ParseCOFFHeader(DataExtractor &data,
                                       lldb::offset_t *offset_ptr,
                                       coff_header_t &coff_header) {
  bool success =
      data.ValidOffsetForDataOfSize(*offset_ptr, sizeof(coff_header));
  if (success) {
    coff_header.machine = data.GetU16(offset_ptr);
    coff_header.nsects = data.GetU16(offset_ptr);
    coff_header.modtime = data.GetU32(offset_ptr);
    coff_header.symoff = data.GetU32(offset_ptr);
    coff_header.nsyms = data.GetU32(offset_ptr);
    coff_header.hdrsize = data.GetU16(offset_ptr);
    coff_header.flags = data.GetU16(offset_ptr);
  }
  if (!success)
    memset(&coff_header, 0, sizeof(coff_header));
  return success;
}

void
DWARFDebugRanges::Dump(Stream &s, const DataExtractor& debug_ranges_data, uint32_t* offset_ptr, dw_addr_t cu_base_addr)
{
    uint32_t addr_size = s.GetAddressByteSize();
    bool verbose = s.GetVerbose();

    dw_addr_t base_addr = cu_base_addr;
    while (debug_ranges_data.ValidOffsetForDataOfSize(*offset_ptr, 2 * addr_size))
    {
        dw_addr_t begin = debug_ranges_data.GetMaxU64(offset_ptr, addr_size);
        dw_addr_t end   = debug_ranges_data.GetMaxU64(offset_ptr, addr_size);
        // Extend 4 byte addresses that consits of 32 bits of 1's to be 64 bits
        // of ones
        if (begin == 0xFFFFFFFFull && addr_size == 4)
            begin = DW_INVALID_ADDRESS;

        s.Indent();
        if (verbose)
        {
            s.AddressRange(begin, end, sizeof (dw_addr_t), " offsets = ");
        }


        if (begin == 0 && end == 0)
        {
            s.PutCString(" End");
            break;
        }
        else if (begin == DW_INVALID_ADDRESS)
        {
            // A base address selection entry
            base_addr = end;
            s.Address(base_addr, sizeof (dw_addr_t), " Base address = ");
        }
        else
        {
            // Convert from offset to an address
            dw_addr_t begin_addr = begin + base_addr;
            dw_addr_t end_addr = end + base_addr;

            s.AddressRange(begin_addr, end_addr, sizeof (dw_addr_t), verbose ? " ==> addrs = " : NULL);
        }
    }
}

//.........这里部分代码省略.........
            Target *target = exe_ctx->GetTargetPtr();
            if (target)
            {
                data.SetByteOrder(target->GetArchitecture().GetByteOrder());
                data.SetAddressByteSize(target->GetArchitecture().GetAddressByteSize());
                break;
            }
        }
        // fallback to host settings
        data.SetByteOrder(endian::InlHostByteOrder());
        data.SetAddressByteSize(sizeof(void *));
        break;
    }

    // Bail if we encountered any errors
    if (error.Fail())
        return error;

    if (address == LLDB_INVALID_ADDRESS)
    {
        error.SetErrorStringWithFormat ("invalid %s address", address_type == eAddressTypeHost ? "host" : "load");
        return error;
    }

    // If we got here, we need to read the value from memory
    size_t byte_size = GetValueByteSize (&error, exe_ctx);

    // Bail if we encountered any errors getting the byte size
    if (error.Fail())
        return error;

    // Make sure we have enough room within "data", and if we don't make
    // something large enough that does
    if (!data.ValidOffsetForDataOfSize (data_offset, byte_size))
    {
        DataBufferSP data_sp(new DataBufferHeap (data_offset + byte_size, '\0'));
        data.SetData(data_sp);
    }

    uint8_t* dst = const_cast<uint8_t*>(data.PeekData (data_offset, byte_size));
    if (dst != NULL)
    {
        if (address_type == eAddressTypeHost)
        {
            // The address is an address in this process, so just copy it.
            if (address == 0)
            {
                error.SetErrorStringWithFormat("trying to read from host address of 0.");
                return error;
            }
            memcpy (dst, (uint8_t*)NULL + address, byte_size);
        }
        else if ((address_type == eAddressTypeLoad) || (address_type == eAddressTypeFile))
        {
            if (file_so_addr.IsValid())
            {
                // We have a file address that we were able to translate into a
                // section offset address so we might be able to read this from
                // the object files if we don't have a live process. Lets always
                // try and read from the process if we have one though since we
                // want to read the actual value by setting "prefer_file_cache"
                // to false. 
                const bool prefer_file_cache = false;
                if (exe_ctx->GetTargetRef().ReadMemory(file_so_addr, prefer_file_cache, dst, byte_size, error) != byte_size)
                {
                    error.SetErrorStringWithFormat("read memory from 0x%" PRIx64 " failed", (uint64_t)address);

bool
RegisterContextMach_i386::WriteRegisterBytes (uint32_t reg, DataExtractor &data, uint32_t data_offset)
{
    int set = GetSetForNativeRegNum (reg);

    if (set == -1)
        return false;

    if (ReadRegisterSet(set, false) != KERN_SUCCESS)
        return false;


    const RegisterInfo * reg_info = GetRegisterInfoAtIndex (reg);
    if (reg_info == NULL && data.ValidOffsetForDataOfSize(data_offset, reg_info->byte_size))
        return false;

    uint32_t offset = data_offset;
    switch (reg)
    {
    case gpr_eax:
    case gpr_ebx:
    case gpr_ecx:
    case gpr_edx:
    case gpr_edi:
    case gpr_esi:
    case gpr_ebp:
    case gpr_esp:
    case gpr_ss:
    case gpr_eflags:
    case gpr_eip:
    case gpr_cs:
    case gpr_ds:
    case gpr_es:
    case gpr_fs:
    case gpr_gs:
        (&gpr.eax)[reg - gpr_eax] = data.GetU32 (&offset);
        break;

    case fpu_fcw:
        fpu.fcw = data.GetU16(&offset);
        break;

    case fpu_fsw:
        fpu.fsw = data.GetU16(&offset);
        break;

    case fpu_ftw:
        fpu.ftw = data.GetU8(&offset);
        break;

    case fpu_fop:
        fpu.fop = data.GetU16(&offset);
        break;

    case fpu_ip:
        fpu.ip = data.GetU32(&offset);
        break;

    case fpu_cs:
        fpu.cs = data.GetU16(&offset);
        break;

    case fpu_dp:
        fpu.dp = data.GetU32(&offset);
        break;

    case fpu_ds:
        fpu.ds = data.GetU16(&offset);
        break;

    case fpu_mxcsr:
        fpu.mxcsr = data.GetU32(&offset);
        break;

    case fpu_mxcsrmask:
        fpu.mxcsrmask = data.GetU32(&offset);
        break;

    case fpu_stmm0:
    case fpu_stmm1:
    case fpu_stmm2:
    case fpu_stmm3:
    case fpu_stmm4:
    case fpu_stmm5:
    case fpu_stmm6:
    case fpu_stmm7:
        ::memcpy (fpu.stmm[reg - fpu_stmm0].bytes, data.PeekData(offset, reg_info->byte_size), reg_info->byte_size);
        return false;

    case fpu_xmm0:
    case fpu_xmm1:
    case fpu_xmm2:
    case fpu_xmm3:
    case fpu_xmm4:
    case fpu_xmm5:
    case fpu_xmm6:
    case fpu_xmm7:
        // These values don't fit into scalar types, RegisterContext::ReadRegisterBytes()
        // must be used for these registers
        ::memcpy (fpu.xmm[reg - fpu_xmm0].bytes, data.PeekData(offset, reg_info->byte_size), reg_info->byte_size);
//.........这里部分代码省略.........

lldb::offset_t
ObjectContainerBSDArchive::Object::Extract (const DataExtractor& data, lldb::offset_t offset)
{
    size_t ar_name_len = 0;
    std::string str;
    char *err;
    
    
    // File header
    //
    // The common format is as follows.
    //
    //  Offset  Length	Name            Format
    //  0       16      File name       ASCII right padded with spaces (no spaces allowed in file name)
    //  16      12      File mod        Decimal as cstring right padded with spaces
    //  28      6       Owner ID        Decimal as cstring right padded with spaces
    //  34      6       Group ID        Decimal as cstring right padded with spaces
    //  40      8       File mode       Octal   as cstring right padded with spaces
    //  48      10      File byte size  Decimal as cstring right padded with spaces
    //  58      2       File magic      0x60 0x0A

    // Make sure there is enough data for the file header and bail if not
    if (!data.ValidOffsetForDataOfSize(offset, 60))
        return LLDB_INVALID_OFFSET;

    str.assign ((const char *)data.GetData(&offset, 16),    16);
    if (str.find("#1/") == 0)
    {
        // If the name is longer than 16 bytes, or contains an embedded space
        // then it will use this format where the length of the name is
        // here and the name characters are after this header.
        ar_name_len = strtoul(str.c_str() + 3, &err, 10);
    }
    else
    {
        // Strip off any trailing spaces.
        const size_t last_pos = str.find_last_not_of(' ');
        if (last_pos != std::string::npos)
        {
            if (last_pos + 1 < 16)
                str.erase (last_pos + 1);
        }
        ar_name.SetCString(str.c_str());
    }

    str.assign ((const char *)data.GetData(&offset, 12),    12);
    ar_date = strtoul(str.c_str(), &err, 10);

    str.assign ((const char *)data.GetData(&offset, 6), 6);
    ar_uid  = strtoul(str.c_str(), &err, 10);

    str.assign ((const char *)data.GetData(&offset, 6), 6);
    ar_gid  = strtoul(str.c_str(), &err, 10);

    str.assign ((const char *)data.GetData(&offset, 8), 8);
    ar_mode = strtoul(str.c_str(), &err, 8);

    str.assign ((const char *)data.GetData(&offset, 10),    10);
    ar_size = strtoul(str.c_str(), &err, 10);

    str.assign ((const char *)data.GetData(&offset, 2), 2);
    if (str == ARFMAG)
    {
        if (ar_name_len > 0)
        {
            const void *ar_name_ptr = data.GetData(&offset, ar_name_len);
            // Make sure there was enough data for the string value and bail if not
            if (ar_name_ptr == NULL)
                return LLDB_INVALID_OFFSET;
            str.assign ((const char *)ar_name_ptr, ar_name_len);
            ar_name.SetCString (str.c_str());
        }
        ar_file_offset = offset;
        ar_file_size = ar_size - ar_name_len;
        return offset;
    }
    return LLDB_INVALID_OFFSET;
}

//.........这里部分代码省略.........
        if (exe_ctx)
        {
            Target *target = exe_ctx->GetTargetPtr();
            if (target)
            {
                data.SetByteOrder(target->GetArchitecture().GetByteOrder());
                data.SetAddressByteSize(target->GetArchitecture().GetAddressByteSize());
                break;
            }
        }
        // fallback to host settings
        data.SetByteOrder(lldb::endian::InlHostByteOrder());
        data.SetAddressByteSize(sizeof(void *));
        break;
    }

    // Bail if we encountered any errors
    if (error.Fail())
        return error;

    if (address == LLDB_INVALID_ADDRESS)
    {
        error.SetErrorStringWithFormat ("invalid %s address", address_type == eAddressTypeHost ? "host" : "load");
        return error;
    }

    // If we got here, we need to read the value from memory
    uint32_t byte_size = GetValueByteSize (ast_context, &error);

    // Bail if we encountered any errors getting the byte size
    if (error.Fail())
        return error;

    // Make sure we have enough room within "data", and if we don't make
    // something large enough that does
    if (!data.ValidOffsetForDataOfSize (data_offset, byte_size))
    {
        DataBufferSP data_sp(new DataBufferHeap (data_offset + byte_size, '\0'));
        data.SetData(data_sp);
    }

    uint8_t* dst = const_cast<uint8_t*>(data.PeekData (data_offset, byte_size));
    if (dst != NULL)
    {
        if (address_type == eAddressTypeHost)
        {
            // The address is an address in this process, so just copy it
            memcpy (dst, (uint8_t*)NULL + address, byte_size);
        }
        else if ((address_type == eAddressTypeLoad) || (address_type == eAddressTypeFile))
        {
            if (file_so_addr.IsValid())
            {
                // We have a file address that we were able to translate into a
                // section offset address so we might be able to read this from
                // the object files if we don't have a live process. Lets always
                // try and read from the process if we have one though since we
                // want to read the actual value by setting "prefer_file_cache"
                // to false. 
                const bool prefer_file_cache = false;
                if (exe_ctx->GetTargetRef().ReadMemory(file_so_addr, prefer_file_cache, dst, byte_size, error) != byte_size)
                {
                    error.SetErrorStringWithFormat("read memory from 0x%llx failed", (uint64_t)address);
                }
            }
            else
            {
                // The execution context might have a NULL process, but it
                // might have a valid process in the exe_ctx->target, so use
                // the ExecutionContext::GetProcess accessor to ensure we
                // get the process if there is one.
                Process *process = exe_ctx->GetProcessPtr();

                if (process)
                {
                    const size_t bytes_read = process->ReadMemory(address, dst, byte_size, error);
                    if (bytes_read != byte_size)
                        error.SetErrorStringWithFormat("read memory from 0x%llx failed (%u of %u bytes read)", 
                                                       (uint64_t)address, 
                                                       (uint32_t)bytes_read, 
                                                       (uint32_t)byte_size);
                }
                else
                {
                    error.SetErrorStringWithFormat("read memory from 0x%llx failed (invalid process)", (uint64_t)address);                    
                }
            }
        }
        else
        {
            error.SetErrorStringWithFormat ("unsupported AddressType value (%i)", address_type);
        }
    }
    else
    {
        error.SetErrorStringWithFormat ("out of memory");
    }

    return error;
}

// Parse the load commands for an image
uint32_t DynamicLoaderMacOSXDYLD::ParseLoadCommands(const DataExtractor &data,
                                                    ImageInfo &dylib_info,
                                                    FileSpec *lc_id_dylinker) {
  lldb::offset_t offset = 0;
  uint32_t cmd_idx;
  Segment segment;
  dylib_info.Clear(true);

  for (cmd_idx = 0; cmd_idx < dylib_info.header.ncmds; cmd_idx++) {
    // Clear out any load command specific data from DYLIB_INFO since we are
    // about to read it.

    if (data.ValidOffsetForDataOfSize(offset,
                                      sizeof(llvm::MachO::load_command))) {
      llvm::MachO::load_command load_cmd;
      lldb::offset_t load_cmd_offset = offset;
      load_cmd.cmd = data.GetU32(&offset);
      load_cmd.cmdsize = data.GetU32(&offset);
      switch (load_cmd.cmd) {
      case llvm::MachO::LC_SEGMENT: {
        segment.name.SetTrimmedCStringWithLength(
            (const char *)data.GetData(&offset, 16), 16);
        // We are putting 4 uint32_t values 4 uint64_t values so we have to use
        // multiple 32 bit gets below.
        segment.vmaddr = data.GetU32(&offset);
        segment.vmsize = data.GetU32(&offset);
        segment.fileoff = data.GetU32(&offset);
        segment.filesize = data.GetU32(&offset);
        // Extract maxprot, initprot, nsects and flags all at once
        data.GetU32(&offset, &segment.maxprot, 4);
        dylib_info.segments.push_back(segment);
      } break;

      case llvm::MachO::LC_SEGMENT_64: {
        segment.name.SetTrimmedCStringWithLength(
            (const char *)data.GetData(&offset, 16), 16);
        // Extract vmaddr, vmsize, fileoff, and filesize all at once
        data.GetU64(&offset, &segment.vmaddr, 4);
        // Extract maxprot, initprot, nsects and flags all at once
        data.GetU32(&offset, &segment.maxprot, 4);
        dylib_info.segments.push_back(segment);
      } break;

      case llvm::MachO::LC_ID_DYLINKER:
        if (lc_id_dylinker) {
          const lldb::offset_t name_offset =
              load_cmd_offset + data.GetU32(&offset);
          const char *path = data.PeekCStr(name_offset);
          lc_id_dylinker->SetFile(path, FileSpec::Style::native);
          FileSystem::Instance().Resolve(*lc_id_dylinker);
        }
        break;

      case llvm::MachO::LC_UUID:
        dylib_info.uuid = UUID::fromOptionalData(data.GetData(&offset, 16), 16);
        break;

      default:
        break;
      }
      // Set offset to be the beginning of the next load command.
      offset = load_cmd_offset + load_cmd.cmdsize;
    }
  }

  // All sections listed in the dyld image info structure will all either be
  // fixed up already, or they will all be off by a single slide amount that is
  // determined by finding the first segment that is at file offset zero which
  // also has bytes (a file size that is greater than zero) in the object file.

  // Determine the slide amount (if any)
  const size_t num_sections = dylib_info.segments.size();
  for (size_t i = 0; i < num_sections; ++i) {
    // Iterate through the object file sections to find the first section that
    // starts of file offset zero and that has bytes in the file...
    if ((dylib_info.segments[i].fileoff == 0 &&
         dylib_info.segments[i].filesize > 0) ||
        (dylib_info.segments[i].name == "__TEXT")) {
      dylib_info.slide = dylib_info.address - dylib_info.segments[i].vmaddr;
      // We have found the slide amount, so we can exit this for loop.
      break;
    }
  }
  return cmd_idx;
}

uint32_t
DynamicLoaderDarwinKernel::ReadKextSummaries (const Address &kext_summary_addr,
                                              uint32_t image_infos_count, 
                                              OSKextLoadedKextSummary::collection &image_infos)
{
    const ByteOrder endian = m_kernel.GetByteOrder();
    const uint32_t addr_size = m_kernel.GetAddressByteSize();

    image_infos.resize(image_infos_count);
    const size_t count = image_infos.size() * m_kext_summary_header.entry_size;
    DataBufferHeap data(count, 0);
    Error error;
    
    Stream *s = &m_process->GetTarget().GetDebugger().GetOutputStream();

    if (s)
        s->Printf ("Reading %u kext summaries...\n", image_infos_count);
    const bool prefer_file_cache = false;
    const size_t bytes_read = m_process->GetTarget().ReadMemory (kext_summary_addr, 
                                                                 prefer_file_cache,
                                                                 data.GetBytes(), 
                                                                 data.GetByteSize(),
                                                                 error);
    if (bytes_read == count)
    {
        
        DataExtractor extractor (data.GetBytes(), data.GetByteSize(), endian, addr_size);
        uint32_t i=0;
        for (uint32_t kext_summary_offset = 0;
             i < image_infos.size() && extractor.ValidOffsetForDataOfSize(kext_summary_offset, m_kext_summary_header.entry_size); 
             ++i, kext_summary_offset += m_kext_summary_header.entry_size)
        {
            uint32_t offset = kext_summary_offset;
            const void *name_data = extractor.GetData(&offset, KERNEL_MODULE_MAX_NAME);
            if (name_data == NULL)
                break;
            memcpy (image_infos[i].name, name_data, KERNEL_MODULE_MAX_NAME);
            image_infos[i].uuid.SetBytes(extractor.GetData (&offset, 16));
            image_infos[i].address          = extractor.GetU64(&offset);
            if (!image_infos[i].so_address.SetLoadAddress (image_infos[i].address, &m_process->GetTarget()))
                m_process->GetTarget().GetImages().ResolveFileAddress (image_infos[i].address, image_infos[i].so_address);
            image_infos[i].size             = extractor.GetU64(&offset);
            image_infos[i].version          = extractor.GetU64(&offset);
            image_infos[i].load_tag         = extractor.GetU32(&offset);
            image_infos[i].flags            = extractor.GetU32(&offset);
            if ((offset - kext_summary_offset) < m_kext_summary_header.entry_size)
            {
                image_infos[i].reference_list = extractor.GetU64(&offset);
            }
            else
            {
                image_infos[i].reference_list = 0;
            }
//            printf ("[%3u] %*.*s: address=0x%16.16llx, size=0x%16.16llx, version=0x%16.16llx, load_tag=0x%8.8x, flags=0x%8.8x\n", 
//                    i,
//                    KERNEL_MODULE_MAX_NAME, KERNEL_MODULE_MAX_NAME,  (char *)name_data, 
//                    image_infos[i].address, 
//                    image_infos[i].size,
//                    image_infos[i].version,
//                    image_infos[i].load_tag,
//                    image_infos[i].flags);
        }
        if (i < image_infos.size())
            image_infos.resize(i);
    }
    else
    {
        image_infos.clear();
    }
    return image_infos.size();
}