57 lines
1.6 KiB
Python
Executable File
57 lines
1.6 KiB
Python
Executable File
#!/usr/bin/env python3
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import struct
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import sys
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import os
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if len(sys.argv) < 2:
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print('Usage: ' + os.path.basename(sys.argv[0]) + ' input_file')
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exit()
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with open(sys.argv[1], 'r+b') as f:
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f.seek(0)
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hdr = f.read(16)
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if hdr[0] != 0x7f or hdr[1] != ord('E') or hdr[2] != ord('L') or hdr[3] != ord('F'):
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raise Exception('Not an elf file')
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if hdr[4] == 1:
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# 32 bit code
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f.seek(28)
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offset = struct.unpack('<I', f.read(4))[0]
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f.seek(42)
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phsize = struct.unpack('<H', f.read(2))[0]
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phnum = struct.unpack('<H', f.read(2))[0]
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for i in range(0, phnum):
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f.seek(offset + i * phsize)
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t = struct.unpack('<I', f.read(4))[0]
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if t == 7:
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f.seek(28 - 4, 1)
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align = struct.unpack('<I', f.read(4))[0]
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print('Found TLS segment with align = ' + str(align))
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if (align < 32):
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print('TLS segment is underaligned, patching')
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f.seek(-4, 1)
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f.write(struct.pack('<I', 32))
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elif hdr[4] == 2:
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# 64 bit code
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f.seek(32)
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offset = struct.unpack('<Q', f.read(8))[0]
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f.seek(54)
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phsize = struct.unpack('<H', f.read(2))[0]
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phnum = struct.unpack('<H', f.read(2))[0]
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for i in range(0, phnum):
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f.seek(offset + i * phsize)
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t = struct.unpack('<I', f.read(4))[0]
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if t == 7:
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f.seek(48 - 4, 1)
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align = struct.unpack('<Q', f.read(8))[0]
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print('Found TLS segment with align = ' + str(align))
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if (align < 64):
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print('TLS segment is underaligned, patching')
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f.seek(-8, 1)
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f.write(struct.pack('<H', 64))
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else:
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raise Exception('Unknown file class')
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