Merge "check_elf_file: check prebuilts are aligned" into main am: 26bb2346

# - LOCAL_BUILT_MODULE

# - LOCAL_IS_HOST_MODULE

# - LOCAL_MODULE_CLASS

# - TARGET_MAX_PAGE_SIZE_SUPPORTED

# - TARGET_NO_BIONIC_PAGE_SIZE_MACRO

# - intermediates

# - my_installed_module_stem

# - my_prebuilt_src_file

# In addition to $(my_check_elf_file_shared_lib_files), some file paths are

# added by `resolve-shared-libs-for-elf-file-check` from `core/main.mk`.

$(check_elf_files_stamp): PRIVATE_SHARED_LIBRARY_FILES := $(my_check_elf_file_shared_lib_files)

# For different page sizes to work, we must support a larger max page size

# as well as properly reflect page size at runtime. Limit this check, since many

# devices set the max page size (for future proof) than actually use the

# larger page size.

ifeq ($(strip $(TARGET_NO_BIONIC_PAGE_SIZE_MACRO)),true)

$(check_elf_files_stamp): PRIVATE_MAX_PAGE_SIZE_OPT := --max-page-size=$(TARGET_MAX_PAGE_SIZE_SUPPORTED)

else

$(check_elf_files_stamp): PRIVATE_MAX_PAGE_SIZE_OPT :=

endif

$(check_elf_files_stamp): $(my_prebuilt_src_file) $(my_check_elf_file_shared_lib_files) $(CHECK_ELF_FILE) $(LLVM_READOBJ)

	@echo Check prebuilt ELF binary: $<

	$(hide) mkdir -p $(dir $@)

	$(hide) $(CHECK_ELF_FILE) \

	    --skip-bad-elf-magic \

	    --skip-unknown-elf-machine \

	    $(PRIVATE_MAX_PAGE_SIZE_OPT) \

	    $(if $(PRIVATE_SONAME),--soname $(PRIVATE_SONAME)) \

	    $(foreach l,$(PRIVATE_SHARED_LIBRARY_FILES),--shared-lib $(l)) \

	    $(foreach l,$(PRIVATE_SYSTEM_SHARED_LIBRARIES),--system-shared-lib $(l)) \

ELF = collections.namedtuple(

  'ELF',

  ('dt_soname', 'dt_needed', 'imported', 'exported', 'header'))

  ('alignments', 'dt_soname', 'dt_needed', 'imported', 'exported', 'header'))

def _get_os_name():

  @classmethod

  def _read_llvm_readobj(cls, elf_file_path, header, llvm_readobj):

    """Run llvm-readobj and parse the output."""

    cmd = [llvm_readobj, '--dynamic-table', '--dyn-symbols', elf_file_path]

    cmd = [llvm_readobj, '--program-headers', '--dynamic-table',

           '--dyn-symbols', elf_file_path]

    out = subprocess.check_output(cmd, text=True)

    lines = out.splitlines()

    return cls._parse_llvm_readobj(elf_file_path, header, lines)

  def _parse_llvm_readobj(cls, elf_file_path, header, lines):

    """Parse the output of llvm-readobj."""

    lines_it = iter(lines)

    alignments = cls._parse_program_headers(lines_it)

    dt_soname, dt_needed = cls._parse_dynamic_table(elf_file_path, lines_it)

    imported, exported = cls._parse_dynamic_symbols(lines_it)

    return ELF(dt_soname, dt_needed, imported, exported, header)

    return ELF(alignments, dt_soname, dt_needed, imported, exported, header)

  _PROGRAM_HEADERS_START_PATTERN = 'ProgramHeaders ['

  _PROGRAM_HEADERS_END_PATTERN = ']'

  _PROGRAM_HEADER_START_PATTERN = 'ProgramHeader {'

  _PROGRAM_HEADER_TYPE_PATTERN = re.compile('^\\s+Type:\\s+(.*)$')

  _PROGRAM_HEADER_ALIGN_PATTERN = re.compile('^\\s+Alignment:\\s+(.*)$')

  _PROGRAM_HEADER_END_PATTERN = '}'

  @classmethod

  def _parse_program_headers(cls, lines_it):

    """Parse the dynamic table section."""

    alignments = []

    if not cls._find_prefix(cls._PROGRAM_HEADERS_START_PATTERN, lines_it):

      raise ELFError()

    for line in lines_it:

      # Parse each program header

      if line.strip() == cls._PROGRAM_HEADER_START_PATTERN:

        p_align = None

        p_type = None

        for line in lines_it:

          if line.strip() == cls._PROGRAM_HEADER_END_PATTERN:

            if not p_align:

              raise ELFError("Could not parse alignment from program header!")

            if not p_type:

              raise ELFError("Could not parse type from program header!")

            if p_type.startswith("PT_LOAD "):

              alignments.append(int(p_align))

            break

          match = cls._PROGRAM_HEADER_TYPE_PATTERN.match(line)

          if match:

            p_type = match.group(1)

          match = cls._PROGRAM_HEADER_ALIGN_PATTERN.match(line)

          if match:

            p_align = match.group(1)

      if line == cls._PROGRAM_HEADERS_END_PATTERN:

        break

    return alignments

  _DYNAMIC_SECTION_START_PATTERN = 'DynamicSection ['

      sys.exit(2)

  def check_max_page_size(self, max_page_size):

    for alignment in self._file_under_test.alignments:

      if alignment % max_page_size != 0:

        self._error(f'Load segment has alignment {alignment} but '

                    f'{max_page_size} required.')

        self._note()

        self._note('Fix suggestions:')

        self._note(f'  use linker flag "-Wl,-z,max-page-size={max_page_size}" '

                   f'when compiling this lib')

        # TODO: instead of exiting immediately, we may want to collect the

        # errors from all checks and emit them at once

        sys.exit(2)

  @staticmethod

  def _find_symbol(lib, name, version):

                      help='Ignore the input file with unknown machine ID')

  parser.add_argument('--allow-undefined-symbols', action='store_true',

                      help='Ignore unresolved undefined symbols')

  parser.add_argument('--max-page-size', action='store', type=int,

                      help='Required page size alignment support')

  # Other options

  parser.add_argument('--llvm-readobj',

  checker.check_dt_needed(args.system_shared_lib)

  if args.max_page_size:

    checker.check_max_page_size(args.max_page_size)

  if not args.allow_undefined_symbols:

    checker.check_symbols()