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 from elftools.elf.elffile import ELFFile
  18 from elftools.elf.relocation import RelocationSection
  19
  20
  21 def process_file(filename):
  22     print('Processing file:', filename)
  23     with open(filename, 'rb') as f:
  24         elffile = ELFFile(f)
  25
  26         # Read the .rela.dyn section from the file, by explicitly asking
  27         # ELFFile for this section
  28         # The section names are strings
  29         reladyn_name = '.rela.dyn'
  30         reladyn = elffile.get_section_by_name(reladyn_name)
  31
  32         if not isinstance(reladyn, RelocationSection):
  33             print('  The file has no %s section' % reladyn_name)
  34
  35         print('  %s section with %s relocations' % (
  36             reladyn_name, reladyn.num_relocations()))
  37
  38         for reloc in reladyn.iter_relocations():
  39             print('    Relocation (%s)' % 'RELA' if reloc.is_RELA() else 'REL')
  40             # Relocation entry attributes are available through item lookup
  41             print('      offset = %s' % reloc['r_offset'])
  42
  43
  44 if __name__ == '__main__':
  45     if sys.argv[1] == '--test':
  46         for filename in sys.argv[2:]:
  47             process_file(filename)