From ef7139d3645ca47fbbc36b26d9b9ae9ff2a8698a Mon Sep 17 00:00:00 2001
From: Yifan Wu <shinbokuow@163.com>
Date: Mon, 3 Jan 2022 19:34:51 -0800
Subject: [PATCH] Update applications

---
 os/src/trap/mod.rs            |  4 ++--
 user/Cargo.toml               |  1 +
 user/src/bin/00hello_world.rs |  5 -----
 user/src/bin/03priv_inst.rs   | 17 +++++++++++++++++
 user/src/bin/04priv_csr.rs    | 17 +++++++++++++++++
 5 files changed, 37 insertions(+), 7 deletions(-)
 create mode 100644 user/src/bin/03priv_inst.rs
 create mode 100644 user/src/bin/04priv_csr.rs

diff --git a/os/src/trap/mod.rs b/os/src/trap/mod.rs
index 98ae35cf..5c2ea91e 100644
--- a/os/src/trap/mod.rs
+++ b/os/src/trap/mod.rs
@@ -34,11 +34,11 @@ pub fn trap_handler(cx: &mut TrapContext) -> &mut TrapContext {
         }
         Trap::Exception(Exception::StoreFault) |
         Trap::Exception(Exception::StorePageFault) => {
-            println!("[kernel] PageFault in application, core dumped.");
+            println!("[kernel] PageFault in application, killed by kernel.");
             run_next_app();
         }
         Trap::Exception(Exception::IllegalInstruction) => {
-            println!("[kernel] IllegalInstruction in application, core dumped.");
+            println!("[kernel] IllegalInstruction in application, killed by kernel.");
             run_next_app();
         }
         _ => {
diff --git a/user/Cargo.toml b/user/Cargo.toml
index 817ca525..b7518dde 100644
--- a/user/Cargo.toml
+++ b/user/Cargo.toml
@@ -7,3 +7,4 @@ edition = "2018"
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
 [dependencies]
+riscv = { git = "https://github.com/rcore-os/riscv", features = ["inline-asm"] } 
diff --git a/user/src/bin/00hello_world.rs b/user/src/bin/00hello_world.rs
index f4f0332e..cefa39ba 100644
--- a/user/src/bin/00hello_world.rs
+++ b/user/src/bin/00hello_world.rs
@@ -4,13 +4,8 @@
 #[macro_use]
 extern crate user_lib;
 
-use core::arch::asm;
-
 #[no_mangle]
 fn main() -> i32 {
     println!("Hello, world!");
-    unsafe {
-        asm!("sret");
-    }
     0
 }
diff --git a/user/src/bin/03priv_inst.rs b/user/src/bin/03priv_inst.rs
new file mode 100644
index 00000000..04dac37e
--- /dev/null
+++ b/user/src/bin/03priv_inst.rs
@@ -0,0 +1,17 @@
+#![no_std]
+#![no_main]
+
+#[macro_use]
+extern crate user_lib;
+
+use core::arch::asm;
+
+#[no_mangle]
+fn main() -> i32 {
+    println!("Try to execute privileged instruction in U Mode");
+    println!("Kernel should kill this application!");
+    unsafe {
+        asm!("sret");
+    }
+    0
+}
diff --git a/user/src/bin/04priv_csr.rs b/user/src/bin/04priv_csr.rs
new file mode 100644
index 00000000..fbd678f7
--- /dev/null
+++ b/user/src/bin/04priv_csr.rs
@@ -0,0 +1,17 @@
+#![no_std]
+#![no_main]
+
+#[macro_use]
+extern crate user_lib;
+
+use riscv::register::sstatus::{self, SPP};
+
+#[no_mangle]
+fn main() -> i32 {
+    println!("Try to access privileged CSR in U Mode");
+    println!("Kernel should kill this application!");
+    unsafe {
+        sstatus::set_spp(SPP::User);
+    }
+    0
+}