vmcall/
vmcall.rs

1use libriscv::{Machine, Options, Registers, Result, SyscallRegistry};
2
3fn reserve_stack(regs: &mut Registers<'_>, size: usize) -> Result<u64> {
4    let sp = regs.x(2)?;
5    let new_sp = sp.wrapping_sub(size as u64) & !0xFu64;
6    regs.set_x(2, new_sp)?;
7    Ok(new_sp)
8}
9
10fn main() -> std::result::Result<(), Box<dyn std::error::Error>> {
11    let args: Vec<String> = std::env::args().collect();
12    if args.len() < 2 {
13        eprintln!("Usage: {} [program file] [arguments ...]", args[0]);
14        std::process::exit(1);
15    }
16
17    let elf = std::fs::read(&args[1])?;
18    let options = Options::builder()
19        .max_memory(64 * 1024 * 1024)
20        .args(args[1..].iter())
21        .build()?;
22
23    let registry = SyscallRegistry::empty();
24    let mut machine = Machine::new(elf, options, &registry)?;
25    machine.run(32_000_000)?;
26
27    if let Some(addr) = machine.address_of("my_function")? {
28        machine.setup_vmcall(addr)?;
29        let msg = b"Hello Sandboxed World!\0";
30        let str_addr = {
31            let mut regs = machine.registers()?;
32            reserve_stack(&mut regs, msg.len())?
33        };
34        machine.copy_to_guest(str_addr, msg)?;
35        {
36            let mut regs = machine.registers()?;
37            regs.set_x(10, str_addr)?;
38        }
39        machine.run(u64::MAX)?;
40    } else {
41        eprintln!("Symbol my_function not found");
42    }
43
44    println!("Program exited with status: {}", machine.return_value());
45    Ok(())
46}
vmcall/vmcall.rs

vmcall/
vmcall.rs
