Can't encode an invalid instruction : 0x40000C (bad)

[Alleexxi]

Hello! I'm encountering an issue while assembling the decoded executable. For testing purposes, I'm using a simple Hello World program, and when I attempt to assemble it, I get the following error:

IcedError { error: "Can't encode an invalid instruction : 0x40000C (bad)" }

This is my code:

fn disassemble_exe(exe_bytes: &[u8]) -> Vec<u8> {
    let mut decoder = Decoder::with_ip(64, exe_bytes, 0x00400000, DecoderOptions::NONE);
    let mut assembler = CodeAssembler::new(64).unwrap();

    while decoder.can_decode() {
        assembler.add_instruction(decoder.decode()).unwrap();
    }

    let result = assembler.assemble(0x00400000).unwrap();
    result
}

[Alleexxi]

Am i doing something wrong?

[Alleexxi]

And yes, i tried to filter out invalid instructions but then i get some jump errors

[Alleexxi]

These are the invalid instructions:

Invalid instruction at position 0x989: [255, 8]
Invalid instruction at position 0x15FE: [255, 78]
Invalid instruction at position 0x163F: [255, 73]
Invalid instruction at position 0x1697: [255, 78]
Invalid instruction at position 0x2223: [255, 14]
Invalid instruction at position 0x2275: [255, 8]
Invalid instruction at position 0x22AB: [255, 8]
Invalid instruction at position 0x234A: [15, 177]
Invalid instruction at position 0x23A6: [255, 8]
Invalid instruction at position 0x278E: [72, 137]
Invalid instruction at position 0x35B4: [255, 8]
Invalid instruction at position 0x3655: [255, 8]
Invalid instruction at position 0x570C: [15, 176]
Invalid instruction at position 0x6B14: [255, 3]
Invalid instruction at position 0x6D46: [255, 9]
Invalid instruction at position 0x6D5C: [255, 10]
Invalid instruction at position 0x6D76: [255, 11]
Invalid instruction at position 0x6DA1: [255, 8]
Invalid instruction at position 0x6DE2: [255, 3]
Invalid instruction at position 0x6E41: [255, 8]
Invalid instruction at position 0x6E7A: [255, 8]
Invalid instruction at position 0x6EC7: [255, 8]
Invalid instruction at position 0x6EF4: [255, 8]
Invalid instruction at position 0x6F30: [255, 8]
Invalid instruction at position 0x74DB: [255, 5]
Invalid instruction at position 0x80CD: [137, 126]
Invalid instruction at position 0x9404: [255, 6]
Invalid instruction at position 0x94DB: [255, 14]
Invalid instruction at position 0x950C: [255, 14]
Invalid instruction at position 0x9A82: [255, 8]
Invalid instruction at position 0x9A9C: [255, 8]
Invalid instruction at position 0x9BBF: [255, 9]
Invalid instruction at position 0x9C20: [255, 8]
Invalid instruction at position 0xA04B: [15, 177]
Invalid instruction at position 0xABD8: [255, 8]
Invalid instruction at position 0x1403C: [254, 254]
Invalid instruction at position 0x1403E: [15, 182]
Invalid instruction at position 0x14172: [254, 254]
Invalid instruction at position 0x14174: [72, 191]
Invalid instruction at position 0x14800: [255, 7]
Invalid instruction at position 0x168C7: [65, 198]
Invalid instruction at position 0x16931: [15, 177]
Invalid instruction at position 0x16BC6: [0, 0]
Invalid instruction at position 0x17485: [255, 8]
Invalid instruction at position 0x17840: [255, 13]
Invalid instruction at position 0x179EF: [15, 177]
Invalid instruction at position 0x17AA0: [255, 0]
Invalid instruction at position 0x17ACA: [15, 177]
Invalid instruction at position 0x17AE5: [255, 8]
Invalid instruction at position 0x17B23: [255, 0]
Invalid instruction at position 0x17BED: [255, 3]
Invalid instruction at position 0x17C28: [15, 176]
Invalid instruction at position 0x17C33: [255, 8]
Invalid instruction at position 0x17C57: [255, 8]

[wtfsck]

Seems like you're decoding data as instructions. You need to find the basic blocks so you only try to encode real instructions and not data.

https://en.wikipedia.org/wiki/Basic_block