diff --git a/os/build.rs b/os/build.rs
index 5d0c988..3cd2e06 100644
--- a/os/build.rs
+++ b/os/build.rs
@@ -53,4 +53,4 @@ app_{0}_end:"#,
         )?;
     }
     Ok(())
-}
\ No newline at end of file
+}
diff --git a/os/src/batch.rs b/os/src/batch.rs
index 2698466..2b09e78 100644
--- a/os/src/batch.rs
+++ b/os/src/batch.rs
@@ -3,6 +3,7 @@ use core::arch::asm;
 use lazy_static::lazy_static;
 
 use crate::log_information;
+use crate::sbi::shutdown;
 use crate::sync::single_cell::SingleCell;
 use crate::trap::context::TrapContext;
 
@@ -26,14 +27,13 @@ lazy_static! {
             let num_app_ptr = _num_app as usize as *const usize;
             let num_app = num_app_ptr.read_volatile();
             let mut start_addresses: [usize; MAX_APP_NUMBER + 1] = [0; MAX_APP_NUMBER + 1];
-            let start_addresses_raw: &[usize] = core::slice::from_raw_parts(
-                num_app_ptr.add(1), num_app + 1
-            );
+            let start_addresses_raw: &[usize] =
+                core::slice::from_raw_parts(num_app_ptr.add(1), num_app + 1);
             start_addresses[..=num_app].copy_from_slice(start_addresses_raw);
             AppManager {
                 app_count: num_app,
                 current: 0,
-                start_addresses
+                start_addresses,
             }
         })
     };
@@ -44,10 +44,12 @@ impl AppManager {
         log_information!("[kernel] Application count is {}.", self.app_count);
 
         for i in 0..self.app_count {
-            log_information!("[kernel] Application_{} ({:#x} -> {:#x})",
-                     i,
-                     self.start_addresses[i],
-                     self.start_addresses[i + 1]);
+            log_information!(
+                "[kernel] Application_{} ({:#x} -> {:#x})",
+                i,
+                self.start_addresses[i],
+                self.start_addresses[i + 1]
+            );
         }
     }
 
@@ -66,19 +68,14 @@ impl AppManager {
 
         log_information!("[kernel] Loading application_{}...", app_id);
 
-        core::slice::from_raw_parts_mut(
-            APP_BASE_ADDRESS as *mut u8,
-            APP_SIZE_LIMIT
-        ).fill(0);
+        core::slice::from_raw_parts_mut(APP_BASE_ADDRESS as *mut u8, APP_SIZE_LIMIT).fill(0);
 
         let app_source = core::slice::from_raw_parts(
             self.start_addresses[app_id] as *const u8,
-            self.start_addresses[app_id + 1] - self.start_addresses[app_id]
-        );
-        let app_destination = core::slice::from_raw_parts_mut(
-            APP_BASE_ADDRESS as *mut u8,
-            app_source.len()
+            self.start_addresses[app_id + 1] - self.start_addresses[app_id],
         );
+        let app_destination =
+            core::slice::from_raw_parts_mut(APP_BASE_ADDRESS as *mut u8, app_source.len());
         app_destination.copy_from_slice(app_source);
 
         // 保证指令缓存的更新
@@ -92,7 +89,7 @@ const KERNEL_STACK_SIZE: usize = 4096 * 2;
 
 #[repr(align(4096))]
 struct UserStack {
-    data: [u8; USER_STACK_SIZE]
+    data: [u8; USER_STACK_SIZE],
 }
 
 impl UserStack {
@@ -103,7 +100,7 @@ impl UserStack {
 
 #[repr(align(4096))]
 struct KernelStack {
-    data: [u8; KERNEL_STACK_SIZE]
+    data: [u8; KERNEL_STACK_SIZE],
 }
 
 impl KernelStack {
@@ -120,8 +117,12 @@ impl KernelStack {
     }
 }
 
-static KERNEL_STACK: KernelStack = KernelStack { data: [0; KERNEL_STACK_SIZE]};
-static USER_STACK: UserStack = UserStack { data: [0; USER_STACK_SIZE]};
+static KERNEL_STACK: KernelStack = KernelStack {
+    data: [0; KERNEL_STACK_SIZE],
+};
+static USER_STACK: UserStack = UserStack {
+    data: [0; USER_STACK_SIZE],
+};
 
 pub fn print_app_information() {
     let app_manager = APP_MANAGER.exclusive_borrow();
@@ -131,6 +132,11 @@ pub fn print_app_information() {
 pub fn run_next_application() -> ! {
     let mut app_manager = APP_MANAGER.exclusive_borrow();
     let current_app = app_manager.get_current_app();
+    if current_app >= app_manager.app_count {
+        log_information!("Run out of applications, the os will stop!");
+        shutdown(true);
+    }
+
     unsafe {
         app_manager.load_app(current_app);
     }
@@ -147,12 +153,10 @@ pub fn run_next_application() -> ! {
     unsafe {
         let context_address = KERNEL_STACK.push_context(TrapContext::init_application_context(
             APP_BASE_ADDRESS,
-            USER_STACK.get_sp()
+            USER_STACK.get_sp(),
         )) as *const _ as usize;
         __restore(context_address);
 
         unreachable!()
     }
 }
-
-
diff --git a/os/src/console.rs b/os/src/console.rs
index 7d2b0cf..e88704f 100644
--- a/os/src/console.rs
+++ b/os/src/console.rs
@@ -1,6 +1,6 @@
+use crate::sbi::console_print;
 use core::fmt;
 use core::fmt::Write;
-use crate::sbi::console_print;
 
 struct Stdout;
 
@@ -65,4 +65,4 @@ macro_rules! log_trace {
     ($fmt: literal $(, $($arg: tt)+)?) => {
         $crate::console::print(format_args!(concat!("\x1b[90m" ,concat!($fmt, "\x1b[0m\n")) $(, $($arg)+)?));
     }
-}
\ No newline at end of file
+}
diff --git a/os/src/main.rs b/os/src/main.rs
index af83c41..c2e2c42 100644
--- a/os/src/main.rs
+++ b/os/src/main.rs
@@ -1,21 +1,20 @@
 #![no_std]
 #![no_main]
 
-use core::arch::global_asm;
 use crate::utils::clear_bss;
+use core::arch::global_asm;
 
-mod utils;
-mod sbi;
-mod console;
 mod batch;
+mod console;
+mod sbi;
 mod sync;
-mod trap;
 mod syscall;
+mod trap;
+mod utils;
 
 global_asm!(include_str!("entry.asm"));
 global_asm!(include_str!("link_app.asm"));
 
-
 #[no_mangle]
 fn rust_main() -> ! {
     clear_bss();
@@ -24,4 +23,3 @@ fn rust_main() -> ! {
     batch::print_app_information();
     batch::run_next_application();
 }
-
diff --git a/os/src/sbi.rs b/os/src/sbi.rs
index 322fb0b..73c351c 100644
--- a/os/src/sbi.rs
+++ b/os/src/sbi.rs
@@ -4,7 +4,7 @@ pub fn console_print(c: usize) {
 }
 
 pub fn shutdown(failure: bool) -> ! {
-    use sbi_rt::{system_reset, Shutdown, NoReason, SystemFailure};
+    use sbi_rt::{system_reset, NoReason, Shutdown, SystemFailure};
 
     if failure {
         system_reset(Shutdown, SystemFailure);
@@ -13,4 +13,4 @@ pub fn shutdown(failure: bool) -> ! {
     }
 
     unreachable!()
-}
\ No newline at end of file
+}
diff --git a/os/src/sync.rs b/os/src/sync.rs
index 5c76622..01d434f 100644
--- a/os/src/sync.rs
+++ b/os/src/sync.rs
@@ -1 +1 @@
-pub mod single_cell;
\ No newline at end of file
+pub mod single_cell;
diff --git a/os/src/sync/single_cell.rs b/os/src/sync/single_cell.rs
index c647797..f6687cd 100644
--- a/os/src/sync/single_cell.rs
+++ b/os/src/sync/single_cell.rs
@@ -2,17 +2,15 @@ use core::cell::{RefCell, RefMut};
 
 /// 只能在单核场景下保持安全的屑RefCell
 pub struct SingleCell<T> {
-    inner: RefCell<T>
+    inner: RefCell<T>,
 }
 
-unsafe impl<T> Sync for SingleCell<T> {
-
-}
+unsafe impl<T> Sync for SingleCell<T> {}
 
 impl<T> SingleCell<T> {
     pub unsafe fn new(value: T) -> SingleCell<T> {
         SingleCell {
-            inner: RefCell::new(value)
+            inner: RefCell::new(value),
         }
     }
 
diff --git a/os/src/syscall/process.rs b/os/src/syscall/process.rs
index b6ec127..619c197 100644
--- a/os/src/syscall/process.rs
+++ b/os/src/syscall/process.rs
@@ -4,4 +4,4 @@ use crate::println;
 pub fn sys_exit(exit_state: i32) -> ! {
     println!("[kernel] Application exited with code {}.", exit_state);
     run_next_application()
-}
\ No newline at end of file
+}
diff --git a/os/src/trap.asm b/os/src/trap.asm
index 3b3811d..7ca7154 100644
--- a/os/src/trap.asm
+++ b/os/src/trap.asm
@@ -38,8 +38,6 @@ __alltraps:
     mv a0, sp
     call trap_handler
 
-
-
 __restore:
     # case1: start running app by __restore
     # case2: back to U after handling trap
diff --git a/os/src/trap.rs b/os/src/trap.rs
index d989dd4..e7aec3e 100644
--- a/os/src/trap.rs
+++ b/os/src/trap.rs
@@ -1,20 +1,22 @@
-use core::arch::global_asm;
-use riscv::register::{
-    mtvec::TrapMode,
-    scause::{self, Exception, Trap},
-    stval, stvec
-};
 use crate::batch::run_next_application;
 use crate::println;
 use crate::syscall::syscall;
 use crate::trap::context::TrapContext;
+use core::arch::global_asm;
+use riscv::register::{
+    mtvec::TrapMode,
+    scause::{self, Exception, Trap},
+    stval, stvec,
+};
 
 pub mod context;
 
 global_asm!(include_str!("trap.asm"));
 
 pub fn init() {
-    extern "C" { fn __alltraps(); }
+    extern "C" {
+        fn __alltraps();
+    }
     unsafe {
         stvec::write(__alltraps as usize, TrapMode::Direct);
     }
@@ -29,19 +31,23 @@ pub fn trap_handler(context: &mut TrapContext) -> &mut TrapContext {
         Trap::Exception(Exception::UserEnvCall) => {
             context.sepc += 4;
             context.x[10] = syscall(context.x[17], [context.x[10], context.x[11], context.x[12]]);
-        },
+        }
         Trap::Exception(Exception::StoreFault) | Trap::Exception(Exception::StorePageFault) => {
             println!("[kernel] PageFault in application, kernel will kill it.");
             run_next_application();
-        },
+        }
         Trap::Exception(Exception::IllegalInstruction) => {
             println!("[kernel] Illegal instruction in application, kernel will kill it.");
             run_next_application();
-        },
+        }
         _ => {
-            panic!("[Kernel] Unsupported trap: {:?}, stval = {:#x}!", scause.cause(), stval);
+            panic!(
+                "[Kernel] Unsupported trap: {:?}, stval = {:#x}!",
+                scause.cause(),
+                stval
+            );
         }
     }
 
     context
-}
\ No newline at end of file
+}
diff --git a/os/src/trap/context.rs b/os/src/trap/context.rs
index 8ef2412..c467b0a 100644
--- a/os/src/trap/context.rs
+++ b/os/src/trap/context.rs
@@ -4,7 +4,7 @@ use riscv::register::sstatus::{self, Sstatus, SPP};
 pub struct TrapContext {
     pub x: [usize; 32],
     pub s_status: Sstatus,
-    pub sepc: usize
+    pub sepc: usize,
 }
 
 impl TrapContext {
@@ -14,7 +14,7 @@ impl TrapContext {
         let mut context = Self {
             x: [0; 32],
             s_status: sstatus,
-            sepc: entry
+            sepc: entry,
         };
 
         context.set_sp(sp);
@@ -26,4 +26,3 @@ impl TrapContext {
         self.x[2] = sp;
     }
 }
-
diff --git a/os/src/utils.rs b/os/src/utils.rs
index 9d5fdad..72f9175 100644
--- a/os/src/utils.rs
+++ b/os/src/utils.rs
@@ -1,17 +1,19 @@
 use core::panic::PanicInfo;
-use crate::println;
+
+use crate::log_error;
 use crate::sbi::shutdown;
 
 #[panic_handler]
 fn panic(info: &PanicInfo) -> ! {
     if let Some(location) = info.location() {
-        println!("Panicked at {}:{} {}.",
+        log_error!(
+            "Panicked at {}:{} {}.",
             location.file(),
             location.line(),
             info.message()
         );
     } else {
-        println!("Panicked: {}.", info.message());
+        log_error!("Panicked: {}.", info.message());
     }
 
     shutdown(true)
@@ -24,8 +26,6 @@ pub fn clear_bss() {
     }
 
     for m in sbss as usize..ebss as usize {
-        unsafe {
-            (m as *mut u8).write_volatile(0)
-        }
+        unsafe { (m as *mut u8).write_volatile(0) }
     }
-}
\ No newline at end of file
+}
diff --git a/user/src/bin/hello_world.rs b/user/src/bin/hello_world.rs
index 5329f79..f457094 100644
--- a/user/src/bin/hello_world.rs
+++ b/user/src/bin/hello_world.rs
@@ -9,4 +9,4 @@ fn main() -> i32 {
     println!("Hello, world!");
 
     0
-}
\ No newline at end of file
+}
diff --git a/user/src/bin/illegal_instruction.rs b/user/src/bin/illegal_instruction.rs
index cbd3210..04dac37 100644
--- a/user/src/bin/illegal_instruction.rs
+++ b/user/src/bin/illegal_instruction.rs
@@ -14,4 +14,4 @@ fn main() -> i32 {
         asm!("sret");
     }
     0
-}
\ No newline at end of file
+}
diff --git a/user/src/bin/power.rs b/user/src/bin/power.rs
index 54fde24..f628f34 100644
--- a/user/src/bin/power.rs
+++ b/user/src/bin/power.rs
@@ -24,4 +24,4 @@ fn main() -> i32 {
     }
     println!("Test power OK!");
     0
-}
\ No newline at end of file
+}
diff --git a/user/src/bin/store_fault.rs b/user/src/bin/store_fault.rs
index aedf88b..f8023eb 100644
--- a/user/src/bin/store_fault.rs
+++ b/user/src/bin/store_fault.rs
@@ -12,4 +12,4 @@ fn main() -> i32 {
         core::ptr::null_mut::<u8>().write_volatile(0);
     }
     0
-}
\ No newline at end of file
+}
diff --git a/user/src/console.rs b/user/src/console.rs
index 0d41582..253fb41 100644
--- a/user/src/console.rs
+++ b/user/src/console.rs
@@ -1,5 +1,5 @@
-use core::fmt::Write;
 use crate::syscall::sys_write;
+use core::fmt::Write;
 
 struct Stdout;
 
@@ -29,4 +29,4 @@ macro_rules! println {
     ($fmt: literal $(, $($arg: tt)+)?) => {
         $crate::console::print(format_args!(concat!($fmt, "\n") $(, $($arg)+)?));
     }
-}
\ No newline at end of file
+}
diff --git a/user/src/lib.rs b/user/src/lib.rs
index 9c42c3f..fbe8862 100644
--- a/user/src/lib.rs
+++ b/user/src/lib.rs
@@ -3,8 +3,8 @@
 
 use crate::syscall::{sys_exit, sys_write};
 
-mod utils;
 mod syscall;
+mod utils;
 #[macro_use]
 pub mod console;
 
@@ -28,4 +28,3 @@ pub fn write(fd: usize, buf: &[u8]) -> isize {
 pub fn exit(exit_code: i32) -> isize {
     sys_exit(exit_code)
 }
-
diff --git a/user/src/syscall.rs b/user/src/syscall.rs
index b4a305d..6025b8e 100644
--- a/user/src/syscall.rs
+++ b/user/src/syscall.rs
@@ -4,7 +4,7 @@ const SYSCALL_WRITE: usize = 64;
 const SYSCALL_EXIT: usize = 93;
 
 fn syscall(id: usize, args: [usize; 3]) -> isize {
-    let mut result : isize;
+    let mut result: isize;
 
     unsafe {
         asm!(
@@ -25,4 +25,4 @@ pub fn sys_write(fd: usize, buffer: &[u8]) -> isize {
 
 pub fn sys_exit(exit_code: i32) -> isize {
     syscall(SYSCALL_EXIT, [exit_code as usize, 0, 0])
-}
\ No newline at end of file
+}
diff --git a/user/src/utils.rs b/user/src/utils.rs
index 85b7f0f..2644afe 100644
--- a/user/src/utils.rs
+++ b/user/src/utils.rs
@@ -1,5 +1,5 @@
-use core::panic::PanicInfo;
 use crate::println;
+use core::panic::PanicInfo;
 
 pub fn clear_bss() {
     extern "C" {
@@ -9,9 +9,7 @@ pub fn clear_bss() {
     }
 
     for i in start_bss as usize..end_bss as usize {
-        unsafe {
-            (i as *mut u8).write_volatile(0)
-        }
+        unsafe { (i as *mut u8).write_volatile(0) }
     }
 }
 
@@ -20,10 +18,15 @@ fn panic_handler(info: &PanicInfo) -> ! {
     let message = info.message();
 
     if let Some(location) = info.location() {
-        println!("Panicked at {}:{} {}", location.file(), location.line(), message);
+        println!(
+            "Panicked at {}:{} {}",
+            location.file(),
+            location.line(),
+            message
+        );
     } else {
         println!("Panicked: {}", message);
     }
 
     unreachable!()
-}
\ No newline at end of file
+}