tools/generate_bad_nexes.py

   1 #!/usr/bin/python
   2 # Copyright 2008, Google Inc.
   3 # All rights reserved.
   4 #
   5 # Redistribution and use in source and binary forms, with or without
   6 # modification, are permitted provided that the following conditions are
   7 # met:
   8 #
   9 #     * Redistributions of source code must retain the above copyright
  10 # notice, this list of conditions and the following disclaimer.
  11 #     * Redistributions in binary form must reproduce the above
  12 # copyright notice, this list of conditions and the following disclaimer
  13 # in the documentation and/or other materials provided with the
  14 # distribution.
  15 #     * Neither the name of Google Inc. nor the names of its
  16 # contributors may be used to endorse or promote products derived from
  17 # this software without specific prior written permission.
  18 #
  19 # THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  20 # "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  21 # LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  22 # A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  23 # OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  24 # SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  25 # LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  26 # DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  27 # THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  28 # (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  29 # OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  30
  31
  32 """
  33 This tool generates bad NaCl modules that should never be generated by
  34 a conformant compiler.  These bad modules are used to test that
  35 sel_ldr correctly detects that these are bad modules.
  36
  37 """
  38
  39 import sys
  40
  41 EHDR_SIZE=52
  42 EI_ABIVERSION_OFFSET=8  # eventually take over set_abi_version?
  43
  44 PHDR_SIZE=32
  45 P_MEMSZ_OFF=(5*4)
  46 PT_LOAD=1
  47 PT_PHDR=6
  48
  49
  50 FILE_MODIFICATIONS=[
  51     [ "fib_scalar.nexe", "integer_overflow_while_madvising.nexe",
  52       [ ( EHDR_SIZE + PHDR_SIZE + P_MEMSZ_OFF + 3, chr(0xbf)),
  53         ]
  54       ],
  55     [ "fib_scalar.nexe", "negative_hole.nexe",
  56       [ ( EHDR_SIZE + PHDR_SIZE + P_MEMSZ_OFF + 3, chr(0xf)),
  57         ],
  58       ],
  59     [ "fib_scalar.nexe", "text_too_big.nexe",
  60       [ ( EHDR_SIZE + PHDR_SIZE + P_MEMSZ_OFF + 3, chr(0x5f)),
  61         ],
  62       ],
  63     ]
  64
  65
  66 def UpdateData(data, change_list):
  67   for ix, replacement_byte in change_list:
  68     data = data[:ix] + replacement_byte + data[ix+1:]
  69   return data
  70
  71
  72 def UpdateFileWithChangeList(src_file, dst_file, change_list):
  73   data = open(src_file).read()
  74   data = UpdateData(data, change_list)
  75   open(dst_file, 'w').write(data)
  76
  77 if __name__ == '__main__':
  78   for src_file, dst_file, cl in FILE_MODIFICATIONS:
  79     UpdateFileWithChangeList(src_file, dst_file, cl)
  80   sys.exit(0)