59 lines
1.7 KiB
Python
59 lines
1.7 KiB
Python
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#!/usr/bin/env python
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#
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# Patches the malloc() function in libmalloc.so to allocate more than the
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# specified number of bytes. This is needed to work around issues with the
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# compiler occasionally crashing.
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#
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# This script replaces the "move a1, a0" (00 80 28 25) instruction with
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# "addiu a1, a0, n" (24 85 nn nn), which causes the malloc function to add n to
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# the size parameter that was passed in.
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import hashlib
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import os.path
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import sys
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# file to patch
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filename = 'tools/ido5.3_compiler/lib/libmalloc.so'
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# Expected (unpatched) hash of file
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filehash = 'adde672b5d79b52ca3cce9a47c7cb648'
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# location in file to patch
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address = 0xAB4
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# Get parameter
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if len(sys.argv) != 2:
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print('Usage: ' + sys.argv[0] + ' n\n where n is the number of extra bytes to allocate in malloc()')
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exit(1)
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n = int(sys.argv[1])
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# Original instruction "move a1, a0"
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oldinsn = bytearray([0x00, 0x80, 0x28, 0x25])
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# New instruction "addiu a1, a0, n"
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newinsn = bytearray([0x24, 0x85, (n >> 8) & 0xFF, (n & 0xFF)])
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# Patch the file
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try:
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with open(filename, 'rb+') as f:
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# Read file contents
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contents = bytearray(f.read())
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# Unpatch the file by restoring original instruction
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contents[address:address+4] = oldinsn
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# Verify the (unpatched) hash of the file
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md5 = hashlib.md5()
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md5.update(contents)
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if md5.hexdigest() != filehash:
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print('Error: ' + filename + ' does not appear to be the correct version.')
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exit(1)
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# Patch the file
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if n != 0:
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contents[address:address+4] = newinsn
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# Write file
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f.seek(0, os.SEEK_SET)
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f.write(contents)
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except IOError as e:
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print('Error: Could not open library file for writing: ' + str(e))
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