Function syscall::scheme::calc_seek_offset_isize

pub fn calc_seek_offset_isize(
    cur_offset: isize, 
    pos: isize, 
    whence: usize, 
    buf_len: isize
) -> Result<isize>

Helper for seek calls Result is guaranteed to be positive. EOVERFLOW returned if the arguments would cause an overflow. EINVAL returned if the new offset is out of bounds.