rust-tests: Some RISC-V emulation tests

There were previously no RISC-V emulation tests at all.

Now there is a happy-path test of successfully executing a single
instruction, along with two different ways of hooking an invalid
instruction (using either general interrupt hook or invalid instruction
hook) and also using general interrupt hook to handle an ecall instruction.

tests/rust-tests/main.rs

@@ -3,9 +3,11 @@ extern crate alloc;
 use alloc::rc::Rc;
 use core::cell::RefCell;
 use unicorn_engine::unicorn_const::{
-    uc_error, Arch, HookType, MemType, Mode, Permission, SECOND_SCALE, TlbEntry, TlbType
+    uc_error, Arch, HookType, MemType, Mode, Permission, TlbEntry, TlbType, SECOND_SCALE,
+};
+use unicorn_engine::{
+    InsnSysX86, RegisterARM, RegisterMIPS, RegisterPPC, RegisterRISCV, RegisterX86, Unicorn,
 };
-use unicorn_engine::{InsnSysX86, RegisterARM, RegisterMIPS, RegisterPPC, RegisterX86, Unicorn};
 
 pub static X86_REGISTERS: [RegisterX86; 125] = [
     RegisterX86::AH,
@@ -623,6 +625,218 @@ fn emulate_ppc() {
     assert_eq!(emu.reg_read(RegisterPPC::R26), Ok(1379));
 }
 
+#[test]
+fn emulate_riscv64() {
+    let riscv_code: Vec<u8> = vec![0x13, 0x05, 0xa5, 0x00]; // addi a0, a0, 10
+
+    let mut emu = unicorn_engine::Unicorn::new(Arch::RISCV, Mode::RISCV64)
+        .expect("failed to initialize unicorn instance");
+    assert_eq!(emu.reg_write(RegisterRISCV::A0, 123), Ok(()));
+    assert_eq!(emu.reg_read(RegisterRISCV::A0), Ok(123));
+
+    // Attempt to write to memory before mapping it.
+    assert_eq!(
+        emu.mem_write(0x1000, &riscv_code),
+        (Err(uc_error::WRITE_UNMAPPED))
+    );
+
+    assert_eq!(emu.mem_map(0x1000, 0x4000, Permission::ALL), Ok(()));
+    assert_eq!(emu.mem_write(0x1000, &riscv_code), Ok(()));
+    assert_eq!(
+        emu.mem_read_as_vec(0x1000, riscv_code.len()),
+        Ok(riscv_code.clone())
+    );
+
+    assert_eq!(
+        emu.emu_start(
+            0x1000,
+            (0x1000 + riscv_code.len()) as u64,
+            10 * SECOND_SCALE,
+            1000
+        ),
+        Ok(())
+    );
+    assert_eq!(emu.reg_read(RegisterRISCV::A0), Ok(123 + 10));
+}
+
+#[test]
+fn emulate_riscv64_invalid_insn_hook() {
+    let riscv_code: Vec<u8> = vec![0x73, 0x10, 0x00, 0xc0]; // "unimp"
+
+    struct Data {
+        invalid_hook_called: bool,
+    }
+
+    let mut emu = unicorn_engine::Unicorn::new_with_data(
+        Arch::RISCV,
+        Mode::RISCV64,
+        Data {
+            invalid_hook_called: false,
+        },
+    )
+    .expect("failed to initialize unicorn instance");
+
+    // Attempt to write to memory before mapping it.
+    assert_eq!(
+        emu.mem_write(0x1000, &riscv_code),
+        (Err(uc_error::WRITE_UNMAPPED))
+    );
+
+    assert_eq!(emu.mem_map(0x1000, 0x4000, Permission::ALL), Ok(()));
+    assert_eq!(emu.mem_write(0x1000, &riscv_code), Ok(()));
+    assert_eq!(
+        emu.mem_read_as_vec(0x1000, riscv_code.len()),
+        Ok(riscv_code.clone())
+    );
+
+    emu.add_insn_invalid_hook(|emu| {
+        let data = emu.get_data_mut();
+        data.invalid_hook_called = true;
+        emu.emu_stop().expect("failed to stop");
+        false
+    })
+    .expect("failed to add invalid instruction hook");
+
+    assert_eq!(
+        emu.emu_start(
+            0x1000,
+            (0x1000 + riscv_code.len()) as u64,
+            10 * SECOND_SCALE,
+            1000
+        ),
+        Ok(())
+    );
+
+    assert!(
+        emu.get_data().invalid_hook_called,
+        "invalid instruction hook was not called"
+    );
+}
+
+#[test]
+fn emulate_riscv64_invalid_insn_interrupt() {
+    let riscv_code: Vec<u8> = vec![0x73, 0x10, 0x00, 0xc0]; // "unimp"
+
+    struct Data {
+        hook_calls: usize,
+        mcause: Option<u32>,
+    }
+
+    let mut emu = unicorn_engine::Unicorn::new_with_data(
+        Arch::RISCV,
+        Mode::RISCV64,
+        Data {
+            hook_calls: 0,
+            mcause: None,
+        },
+    )
+    .expect("failed to initialize unicorn instance");
+
+    // Attempt to write to memory before mapping it.
+    assert_eq!(
+        emu.mem_write(0x1000, &riscv_code),
+        (Err(uc_error::WRITE_UNMAPPED))
+    );
+
+    assert_eq!(emu.mem_map(0x1000, 0x4000, Permission::ALL), Ok(()));
+    assert_eq!(emu.mem_write(0x1000, &riscv_code), Ok(()));
+    assert_eq!(
+        emu.mem_read_as_vec(0x1000, riscv_code.len()),
+        Ok(riscv_code.clone())
+    );
+
+    emu.add_intr_hook(|emu, mcause| {
+        let data = emu.get_data_mut();
+        data.hook_calls += 1;
+        data.mcause = Some(mcause);
+        emu.emu_stop().expect("failed to stop");
+    })
+    .expect("failed to add interrupt hook");
+
+    assert_eq!(
+        emu.emu_start(
+            0x1000,
+            (0x1000 + riscv_code.len()) as u64,
+            10 * SECOND_SCALE,
+            1000
+        ),
+        Ok(())
+    );
+
+    assert_eq!(
+        emu.get_data().hook_calls,
+        1,
+        "interrupt hook should have been called exactly once"
+    );
+    assert_eq!(
+        emu.get_data().mcause,
+        Some(2_u32),
+        "wrong mcause value for illegal instruction"
+    );
+}
+
+#[test]
+fn emulate_riscv64_ecall_interrupt() {
+    let riscv_code: Vec<u8> = vec![0x73, 0x00, 0x00, 0x00]; // ecall
+
+    struct Data {
+        hook_calls: usize,
+        mcause: Option<u32>,
+    }
+
+    let mut emu = unicorn_engine::Unicorn::new_with_data(
+        Arch::RISCV,
+        Mode::RISCV64,
+        Data {
+            hook_calls: 0,
+            mcause: None,
+        },
+    )
+    .expect("failed to initialize unicorn instance");
+
+    // Attempt to write to memory before mapping it.
+    assert_eq!(
+        emu.mem_write(0x1000, &riscv_code),
+        (Err(uc_error::WRITE_UNMAPPED))
+    );
+
+    assert_eq!(emu.mem_map(0x1000, 0x4000, Permission::ALL), Ok(()));
+    assert_eq!(emu.mem_write(0x1000, &riscv_code), Ok(()));
+    assert_eq!(
+        emu.mem_read_as_vec(0x1000, riscv_code.len()),
+        Ok(riscv_code.clone())
+    );
+
+    emu.add_intr_hook(|emu, mcause| {
+        let data = emu.get_data_mut();
+        data.hook_calls += 1;
+        data.mcause = Some(mcause);
+        emu.emu_stop().expect("failed to stop");
+    })
+    .expect("failed to add interrupt hook");
+
+    assert_eq!(
+        emu.emu_start(
+            0x1000,
+            (0x1000 + riscv_code.len()) as u64,
+            10 * SECOND_SCALE,
+            1000
+        ),
+        Ok(())
+    );
+
+    assert_eq!(
+        emu.get_data().hook_calls,
+        1,
+        "interrupt hook should have been called exactly once"
+    );
+    assert_eq!(
+        emu.get_data().mcause,
+        Some(8_u32),
+        "wrong mcause value for ecall from U-Mode"
+    );
+}
+
 #[test]
 fn mem_unmapping() {
     let mut emu = unicorn_engine::Unicorn::new(Arch::X86, Mode::MODE_32)