1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36

/// Syscall errors
#[derive(Eq, PartialEq, Debug, Clone, Copy)]
pub enum SysError {
    /// Index out of bound
    IndexOutOfBound,
    /// Field is missing for the target
    ItemMissing,
    /// Buffer length is not enough, error contains actual data length
    LengthNotEnough(usize),
    /// Data encoding error
    Encoding,
    /// Unknown syscall error number
    Unknown(u64),
}

impl SysError {
    pub(crate) fn build_syscall_result(
        errno: u64,
        load_len: usize,
        actual_data_len: usize,
    ) -> Result<usize, SysError> {
        use SysError::*;

        match errno {
            0 => {
                if actual_data_len > load_len {
                    return Err(LengthNotEnough(actual_data_len));
                }
                return Ok(actual_data_len);
            }
            1 => Err(IndexOutOfBound),
            2 => Err(ItemMissing),
            _ => Err(Unknown(errno)),
        }
    }
}