examples/elf_relocations.py

   1 #-------------------------------------------------------------------------------
   2 # elftools example: elf_relocations.py
   3 #
   4 # An example of obtaining a relocation section from an ELF file and examining
   5 # the relocation entries it contains.
   6 #
   7 # Eli Bendersky (eliben@gmail.com)
   8 # This code is in the public domain
   9 #-------------------------------------------------------------------------------
  10 from __future__ import print_function
  11 import sys
  12
  13 # If pyelftools is not installed, the example can also run from the root or
  14 # examples/ dir of the source distribution.
  15 sys.path[0:0] = ['.', '..']
  16
  17
  18 from elftools.common.py3compat import bytes2str
  19 from elftools.elf.elffile import ELFFile
  20 from elftools.elf.relocation import RelocationSection
  21
  22
  23 def process_file(filename):
  24     print('Processing file:', filename)
  25     with open(filename, 'rb') as f:
  26         elffile = ELFFile(f)
  27
  28         # Read the .rela.dyn section from the file, by explicitly asking
  29         # ELFFile for this section
  30         # The section names are strings
  31         reladyn_name = '.rela.dyn'
  32         reladyn = elffile.get_section_by_name(reladyn_name)
  33
  34         if not isinstance(reladyn, RelocationSection):
  35             print('  The file has no %s section' % reladyn_name)
  36
  37         print('  %s section with %s relocations' % (
  38             reladyn_name, reladyn.num_relocations()))
  39
  40         for reloc in reladyn.iter_relocations():
  41             print('    Relocation (%s)' % 'RELA' if reloc.is_RELA() else 'REL')
  42             # Relocation entry attributes are available through item lookup
  43             print('      offset = %s' % reloc['r_offset'])
  44
  45
  46 if __name__ == '__main__':
  47     for filename in sys.argv[1:]:
  48         process_file(filename)
  49