Update applications

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();
         }
         _ => {

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"] } 

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
 }

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
+}

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
+}