test/test_dynamic.py

   1 #-------------------------------------------------------------------------------
   2 # elftools tests
   3 #
   4 # Eli Bendersky (eliben@gmail.com)
   5 # This code is in the public domain
   6 #-------------------------------------------------------------------------------
   7 import unittest
   8 import os
   9
  10 from elftools.elf.elffile import ELFFile
  11 from elftools.common.exceptions import ELFError
  12 from elftools.elf.dynamic import DynamicTag
  13 from elftools.elf.enums import ENUM_D_TAG
  14 from elftools.elf.descriptions import _DESCR_D_TAG, _low_priority_D_TAG
  15
  16
  17 class TestDynamicTag(unittest.TestCase):
  18     """Tests for the DynamicTag class."""
  19
  20     def test_requires_stringtable(self):
  21         with self.assertRaises(ELFError):
  22             dt = DynamicTag('', None)
  23
  24     def test_tag_priority(self):
  25         for tag in _low_priority_D_TAG:
  26             val = ENUM_D_TAG[tag]
  27             # if the low priority tag is present in the descriptions,
  28             # assert that it has not overridden any other tag
  29             if _DESCR_D_TAG[val] == tag:
  30                 for tag2 in ENUM_D_TAG:
  31                     if tag2 == tag:
  32                         continue
  33                     self.assertNotEqual(ENUM_D_TAG[tag2], val)
  34
  35
  36 class TestDynamic(unittest.TestCase):
  37     """Tests for the Dynamic class."""
  38
  39     def test_missing_sections(self):
  40         """Verify we can get dynamic strings w/out section headers"""
  41
  42         libs = []
  43         with open(os.path.join('test', 'testfiles_for_unittests',
  44                                'aarch64_super_stripped.elf'), 'rb') as f:
  45             elf = ELFFile(f)
  46             for segment in elf.iter_segments():
  47                 if segment.header.p_type != 'PT_DYNAMIC':
  48                     continue
  49
  50                 for t in segment.iter_tags():
  51                     if t.entry.d_tag == 'DT_NEEDED':
  52                         libs.append(t.needed)
  53
  54         exp = ['libc.so.6']
  55         self.assertEqual(libs, exp)
  56
  57     def test_reading_symbols_elf_hash(self):
  58         """ Verify we can read symbol table without SymbolTableSection but with
  59             a SYSV-style symbol hash table"""
  60         with open(os.path.join('test', 'testfiles_for_unittests',
  61                                'aarch64_super_stripped.elf'), 'rb') as f:
  62             elf = ELFFile(f)
  63             for segment in elf.iter_segments():
  64                 if segment.header.p_type != 'PT_DYNAMIC':
  65                     continue
  66
  67                 num_symbols = segment.num_symbols()
  68                 symbol_names = [x.name for x in segment.iter_symbols()]
  69                 symbol_at_index_3 = segment.get_symbol(3)
  70                 symbols_abort = segment.get_symbol_by_name('abort')
  71
  72         self.assertEqual(num_symbols, 4)
  73         exp = ['', '__libc_start_main', '__gmon_start__', 'abort']
  74         self.assertEqual(symbol_names, exp)
  75         self.assertEqual(symbol_at_index_3.name, 'abort')
  76         self.assertIsNotNone(symbols_abort)
  77
  78     def test_reading_symbols_gnu_hash(self):
  79         """ Verify we can read symbol table without SymbolTableSection but with
  80             a GNU symbol hash table"""
  81         with open(os.path.join('test', 'testfiles_for_unittests',
  82                                'android_dyntags.elf'), 'rb') as f:
  83             elf = ELFFile(f)
  84             for segment in elf.iter_segments():
  85                 if segment.header.p_type != 'PT_DYNAMIC':
  86                     continue
  87
  88                 num_symbols = segment.num_symbols()
  89                 symbol_names = [x.name for x in segment.iter_symbols()]
  90                 symbol_at_index_3 = segment.get_symbol(3)
  91                 symbols_atfork = segment.get_symbol_by_name('__register_atfork')
  92
  93         self.assertEqual(num_symbols, 212)
  94         exp = ['', '__cxa_finalize' , '__cxa_atexit', '__register_atfork',
  95                '__stack_chk_fail', '_ZNK7android7RefBase9decStrongEPKv',
  96                '_ZN7android7RefBaseD2Ev', '_ZdlPv', 'pthread_mutex_lock']
  97         self.assertEqual(symbol_names[:9], exp)
  98         self.assertEqual(symbol_at_index_3.name, '__register_atfork')
  99         self.assertIsNotNone(symbols_atfork)
 100
 101     def test_sunw_tags(self):
 102         def extract_sunw(filename):
 103             with open(filename, 'rb') as f:
 104                 elf = ELFFile(f)
 105                 dyn = elf.get_section_by_name('.dynamic')
 106
 107                 seen = set()
 108                 for tag in dyn.iter_tags():
 109                     if type(tag.entry.d_tag) is str and \
 110                             tag.entry.d_tag.startswith("DT_SUNW"):
 111                         seen.add(tag.entry.d_tag)
 112
 113             return seen
 114
 115         f1 = extract_sunw(os.path.join('test', 'testfiles_for_unittests',
 116             'exe_solaris32_cc.sparc.elf'))
 117         f2 = extract_sunw(os.path.join('test', 'testfiles_for_unittests',
 118             'android_dyntags.elf'))
 119         self.assertEqual(f1, {'DT_SUNW_STRPAD', 'DT_SUNW_LDMACH'})
 120         self.assertEqual(f2, set())
 121
 122 if __name__ == '__main__':
 123     unittest.main()