diff --git a/.github/workflows/doc-and-test.yml b/.github/workflows/doc-and-test.yml
index 9fee30e..0a05371 100644
--- a/.github/workflows/doc-and-test.yml
+++ b/.github/workflows/doc-and-test.yml
@@ -4,7 +4,7 @@ on: [push]
 
 env:
   CARGO_TERM_COLOR: always
-  rust_toolchain: nightly-2025-02-18
+  rust_toolchain: nightly-2024-01-18
 
 jobs:
   build-doc:
@@ -49,10 +49,7 @@ jobs:
       - name: Install QEMU
         run: |
           sudo apt-get update
-          sudo apt-get install autoconf automake autotools-dev curl libmpc-dev libmpfr-dev libgmp-dev \
-                               gawk build-essential bison flex texinfo gperf libtool patchutils bc \
-                               zlib1g-dev libexpat-dev pkg-config  libglib2.0-dev libpixman-1-dev libsdl2-dev libslirp-dev \
-                               python3 python3-pip ninja-build -y
+          sudo apt-get install ninja-build -y
           if [ ! -d qemu-7.0.0 ]; then
             wget https://download.qemu.org/qemu-7.0.0.tar.xz
             tar -xf qemu-7.0.0.tar.xz
diff --git a/easy-fs-fuse/src/main.rs b/easy-fs-fuse/src/main.rs
index 39b9eaf..09016c3 100644
--- a/easy-fs-fuse/src/main.rs
+++ b/easy-fs-fuse/src/main.rs
@@ -149,59 +149,3 @@ fn efs_test() -> std::io::Result<()> {
 
     Ok(())
 }
-
-#[test]
-fn mac_test() -> std::io::Result<()> {
-    const BLOCK_SZ: usize = 512;
-
-    let block_file = Arc::new(BlockFile(Mutex::new({
-        let f = OpenOptions::new()
-            .read(true)
-            .write(true)
-            .create(true)
-            .open("target/fs_mac.img")?;
-        f.set_len(8192 * BLOCK_SZ).unwrap();
-        f
-    })));
-
-    EasyFileSystem::create(block_file.clone(), 4096, 1);
-    let efs = EasyFileSystem::open(block_file.clone());
-    let root_inode = EasyFileSystem::root_inode(&efs);
-
-    root_inode.create("root_file");
-    root_inode.create("public_file");
-
-    let secret_inode = root_inode.find("root_file").unwrap();
-    secret_inode.write_at(0, b"TOP SECRET: root only!");
-    let public_inode = root_inode.find("public_file").unwrap();
-    public_inode.write_at(0, b"This file is public.");
-
-    let check_permission = |user: &str, filename: &str| -> bool {
-        if filename == "root_file" && user != "root" {
-            false
-        } else {
-            true
-        }
-    };
-
-    let users = ["root", "nonroot"];
-    for user in users.iter() {
-        println!("{} task:", user);
-
-        for filename in ["root_file", "public_file"].iter() {
-            if check_permission(user, filename) {
-                let inode = root_inode.find(filename).unwrap();
-                let mut buf = [0u8; 128];
-                let len = inode.read_at(0, &mut buf);
-                let content = core::str::from_utf8(&buf[..len]).unwrap();
-                println!("{}: Opened successfully");
-            } else {
-                println!("{}: Permission denied");
-            }
-        }
-
-        println!();
-    }
-
-    Ok(())
-}
diff --git a/easy-fs/src/block_cache.rs b/easy-fs/src/block_cache.rs
index 786f9e0..c9bfa26 100644
--- a/easy-fs/src/block_cache.rs
+++ b/easy-fs/src/block_cache.rs
@@ -1,56 +1,12 @@
 use super::{BlockDevice, BLOCK_SZ};
-use alloc::boxed::Box;
 use alloc::collections::VecDeque;
 use alloc::sync::Arc;
-use core::alloc::Layout;
-use core::mem::ManuallyDrop;
-use core::ptr::{addr_of, addr_of_mut};
-use core::slice;
 use lazy_static::*;
 use spin::Mutex;
-
-/// Use `ManuallyDrop` to ensure data is deallocated with an alignment of `BLOCK_SZ`
-struct CacheData(ManuallyDrop<Box<[u8; BLOCK_SZ]>>);
-
-impl CacheData {
-    pub fn new() -> Self {
-        let data = unsafe {
-            let raw = alloc::alloc::alloc(Self::layout());
-            Box::from_raw(raw as *mut [u8; BLOCK_SZ])
-        };
-        Self(ManuallyDrop::new(data))
-    }
-
-    fn layout() -> Layout {
-        Layout::from_size_align(BLOCK_SZ, BLOCK_SZ).unwrap()
-    }
-}
-
-impl Drop for CacheData {
-    fn drop(&mut self) {
-        let ptr = self.0.as_mut_ptr();
-        unsafe { alloc::alloc::dealloc(ptr, Self::layout()) };
-    }
-}
-
-impl AsRef<[u8]> for CacheData {
-    fn as_ref(&self) -> &[u8] {
-        let ptr = self.0.as_ptr() as *const u8;
-        unsafe { slice::from_raw_parts(ptr, BLOCK_SZ) }
-    }
-}
-
-impl AsMut<[u8]> for CacheData {
-    fn as_mut(&mut self) -> &mut [u8] {
-        let ptr = self.0.as_mut_ptr() as *mut u8;
-        unsafe { slice::from_raw_parts_mut(ptr, BLOCK_SZ) }
-    }
-}
-
 /// Cached block inside memory
 pub struct BlockCache {
     /// cached block data
-    cache: CacheData,
+    cache: [u8; BLOCK_SZ],
     /// underlying block id
     block_id: usize,
     /// underlying block device
@@ -62,9 +18,8 @@ pub struct BlockCache {
 impl BlockCache {
     /// Load a new BlockCache from disk.
     pub fn new(block_id: usize, block_device: Arc<dyn BlockDevice>) -> Self {
-        // for alignment and move effciency
-        let mut cache = CacheData::new();
-        block_device.read_block(block_id, cache.as_mut());
+        let mut cache = [0u8; BLOCK_SZ];
+        block_device.read_block(block_id, &mut cache);
         Self {
             cache,
             block_id,
@@ -73,12 +28,8 @@ impl BlockCache {
         }
     }
     /// Get the address of an offset inside the cached block data
-    fn addr_of_offset(&self, offset: usize) -> *const u8 {
-        addr_of!(self.cache.as_ref()[offset])
-    }
-
-    fn addr_of_offset_mut(&mut self, offset: usize) -> *mut u8 {
-        addr_of_mut!(self.cache.as_mut()[offset])
+    fn addr_of_offset(&self, offset: usize) -> usize {
+        &self.cache[offset] as *const _ as usize
     }
 
     pub fn get_ref<T>(&self, offset: usize) -> &T
@@ -87,8 +38,8 @@ impl BlockCache {
     {
         let type_size = core::mem::size_of::<T>();
         assert!(offset + type_size <= BLOCK_SZ);
-        let addr = self.addr_of_offset(offset) as *const T;
-        unsafe { &*addr }
+        let addr = self.addr_of_offset(offset);
+        unsafe { &*(addr as *const T) }
     }
 
     pub fn get_mut<T>(&mut self, offset: usize) -> &mut T
@@ -98,8 +49,8 @@ impl BlockCache {
         let type_size = core::mem::size_of::<T>();
         assert!(offset + type_size <= BLOCK_SZ);
         self.modified = true;
-        let addr = self.addr_of_offset_mut(offset) as *mut T;
-        unsafe { &mut *addr }
+        let addr = self.addr_of_offset(offset);
+        unsafe { &mut *(addr as *mut T) }
     }
 
     pub fn read<T, V>(&self, offset: usize, f: impl FnOnce(&T) -> V) -> V {
@@ -113,8 +64,7 @@ impl BlockCache {
     pub fn sync(&mut self) {
         if self.modified {
             self.modified = false;
-            self.block_device
-                .write_block(self.block_id, self.cache.as_ref());
+            self.block_device.write_block(self.block_id, &self.cache);
         }
     }
 }
diff --git a/easy-fs/src/efs.rs b/easy-fs/src/efs.rs
index e28f6b2..202b9eb 100644
--- a/easy-fs/src/efs.rs
+++ b/easy-fs/src/efs.rs
@@ -36,7 +36,7 @@ impl EasyFileSystem {
         let data_bitmap_blocks = (data_total_blocks + 4096) / 4097;
         let data_area_blocks = data_total_blocks - data_bitmap_blocks;
         let data_bitmap = Bitmap::new(
-            (1 + inode_total_blocks) as usize,
+            (1 + inode_bitmap_blocks + inode_area_blocks) as usize,
             data_bitmap_blocks as usize,
         );
         let mut efs = Self {
diff --git a/os/Cargo.toml b/os/Cargo.toml
index d621557..b65ed6e 100644
--- a/os/Cargo.toml
+++ b/os/Cargo.toml
@@ -2,7 +2,7 @@
 name = "os"
 version = "0.1.0"
 authors = ["Yifan Wu <shinbokuow@163.com>"]
-edition = "2024"
+edition = "2021"
 
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
diff --git a/os/Makefile b/os/Makefile
index ff109f0..9815cee 100644
--- a/os/Makefile
+++ b/os/Makefile
@@ -74,23 +74,20 @@ QEMU_ARGS := -machine virt \
 			 -drive file=$(FS_IMG),if=none,format=raw,id=x0 \
 			 -device virtio-blk-device,drive=x0,bus=virtio-mmio-bus.0
 
-QEMU_NAME := qemu-system-riscv64
-qemu-version-check:
-	@sh scripts/qemu-ver-check.sh $(QEMU_NAME)
-
-run-inner: qemu-version-check build
+run-inner: build
 	@qemu-system-riscv64 $(QEMU_ARGS)
 
-debug: qemu-version-check build
+debug: build
 	@tmux new-session -d \
 		"qemu-system-riscv64 $(QEMU_ARGS) -s -S" && \
 		tmux split-window -h "riscv64-unknown-elf-gdb -ex 'file $(KERNEL_ELF)' -ex 'set arch riscv:rv64' -ex 'target remote localhost:1234'" && \
 		tmux -2 attach-session -d
 
-gdbserver: qemu-version-check build
+
+gdbserver: build
 	@qemu-system-riscv64 $(QEMU_ARGS) -s -S
 
 gdbclient:
 	@riscv64-unknown-elf-gdb -ex 'file $(KERNEL_ELF)' -ex 'set arch riscv:rv64' -ex 'target remote localhost:1234'
 
-.PHONY: build env kernel clean disasm disasm-vim run-inner fs-img gdbserver gdbclient qemu-version-check
+.PHONY: build env kernel clean disasm disasm-vim run-inner fs-img gdbserver gdbclient
diff --git a/os/scripts/qemu-ver-check.sh b/os/scripts/qemu-ver-check.sh
deleted file mode 100755
index 40ef766..0000000
--- a/os/scripts/qemu-ver-check.sh
+++ /dev/null
@@ -1,26 +0,0 @@
-#!/bin/sh
-
-# Argument1: The filename of qemu executable, e.g. qemu-system-riscv64
-QEMU_PATH=$(which $1)
-RET=$?
-MINIMUM_MAJOR_VERSION=7
-RED='\033[0;31m'
-GREEN='\033[0;32m'
-NC='\033[0m'
-if [ $RET != 0 ]
-then
-    echo "$1 not found"
-    exit 1
-else
-    QEMU_VERSION=$($1 --version|head -n 1|awk '{print $4}')
-    MAJOR_VERSION=$(echo $QEMU_VERSION | awk -F '.' '{print $1}')
-    if [ $MAJOR_VERSION -lt $MINIMUM_MAJOR_VERSION ]
-    then
-        echo "${RED}Error: Required major version of QEMU is ${MINIMUM_MAJOR_VERSION}, " \
-             "but current is ${QEMU_VERSION}.${NC}"
-        exit 1
-    else
-        echo "${GREEN}QEMU version is ${QEMU_VERSION}(>=${MINIMUM_MAJOR_VERSION}), OK!${NC}"
-        exit 0
-    fi
-fi
diff --git a/os/src/drivers/block/virtio_blk.rs b/os/src/drivers/block/virtio_blk.rs
index 5097831..9755250 100644
--- a/os/src/drivers/block/virtio_blk.rs
+++ b/os/src/drivers/block/virtio_blk.rs
@@ -1,7 +1,7 @@
 use super::BlockDevice;
 use crate::mm::{
-    FrameTracker, PageTable, PhysAddr, PhysPageNum, StepByOne, VirtAddr, frame_alloc,
-    frame_dealloc, kernel_token,
+    frame_alloc, frame_dealloc, kernel_token, FrameTracker, PageTable, PhysAddr, PhysPageNum,
+    StepByOne, VirtAddr,
 };
 use crate::sync::UPSafeCell;
 use alloc::vec::Vec;
diff --git a/os/src/fs/mod.rs b/os/src/fs/mod.rs
index c3cc1e7..6c790fe 100644
--- a/os/src/fs/mod.rs
+++ b/os/src/fs/mod.rs
@@ -15,5 +15,5 @@ pub trait File: Send + Sync {
     fn write(&self, buf: UserBuffer) -> usize;
 }
 
-pub use inode::{OSInode, OpenFlags, list_apps, open_file};
+pub use inode::{list_apps, open_file, OSInode, OpenFlags};
 pub use stdio::{Stdin, Stdout};
diff --git a/os/src/lang_items.rs b/os/src/lang_items.rs
index 79cd51e..26951f8 100644
--- a/os/src/lang_items.rs
+++ b/os/src/lang_items.rs
@@ -10,10 +10,10 @@ fn panic(info: &PanicInfo) -> ! {
             "[kernel] Panicked at {}:{} {}",
             location.file(),
             location.line(),
-            info.message()
+            info.message().unwrap()
         );
     } else {
-        error!("[kernel] Panicked: {}", info.message());
+        error!("[kernel] Panicked: {}", info.message().unwrap());
     }
     shutdown(true)
 }
diff --git a/os/src/logging.rs b/os/src/logging.rs
deleted file mode 100644
index b5421f1..0000000
--- a/os/src/logging.rs
+++ /dev/null
@@ -1,47 +0,0 @@
-/*！
-
-本模块利用 log crate 为你提供了日志功能，使用方式见 main.rs.
-
-*/
-
-use log::{self, Level, LevelFilter, Log, Metadata, Record};
-
-struct SimpleLogger;
-
-impl Log for SimpleLogger {
-    fn enabled(&self, _metadata: &Metadata) -> bool {
-        true
-    }
-    fn log(&self, record: &Record) {
-        if !self.enabled(record.metadata()) {
-            return;
-        }
-        let color = match record.level() {
-            Level::Error => 31, // Red
-            Level::Warn => 93,  // BrightYellow
-            Level::Info => 34,  // Blue
-            Level::Debug => 32, // Green
-            Level::Trace => 90, // BrightBlack
-        };
-        println!(
-            "\u{1B}[{}m[{:>5}] {}\u{1B}[0m",
-            color,
-            record.level(),
-            record.args(),
-        );
-    }
-    fn flush(&self) {}
-}
-
-pub fn init() {
-    static LOGGER: SimpleLogger = SimpleLogger;
-    log::set_logger(&LOGGER).unwrap();
-    log::set_max_level(match option_env!("LOG") {
-        Some("ERROR") => LevelFilter::Error,
-        Some("WARN") => LevelFilter::Warn,
-        Some("INFO") => LevelFilter::Info,
-        Some("DEBUG") => LevelFilter::Debug,
-        Some("TRACE") => LevelFilter::Trace,
-        _ => LevelFilter::Info,
-    });
-}
diff --git a/os/src/main.rs b/os/src/main.rs
index 46161de..cc58958 100644
--- a/os/src/main.rs
+++ b/os/src/main.rs
@@ -23,6 +23,7 @@
 #![allow(unused_imports)]
 #![no_std]
 #![no_main]
+#![feature(panic_info_message)]
 #![feature(alloc_error_handler)]
 
 extern crate alloc;
@@ -30,8 +31,6 @@ extern crate alloc;
 #[macro_use]
 extern crate bitflags;
 
-use log::*;
-
 #[path = "boards/qemu.rs"]
 mod board;
 
@@ -41,7 +40,6 @@ mod config;
 mod drivers;
 pub mod fs;
 pub mod lang_items;
-mod logging;
 pub mod mm;
 pub mod sbi;
 pub mod sync;
@@ -55,9 +53,9 @@ use core::arch::global_asm;
 global_asm!(include_str!("entry.asm"));
 /// clear BSS segment
 fn clear_bss() {
-    unsafe extern "C" {
-        safe fn sbss();
-        safe fn ebss();
+    extern "C" {
+        fn sbss();
+        fn ebss();
     }
     unsafe {
         core::slice::from_raw_parts_mut(sbss as usize as *mut u8, ebss as usize - sbss as usize)
@@ -65,12 +63,11 @@ fn clear_bss() {
     }
 }
 
+#[no_mangle]
 /// the rust entry-point of os
-#[unsafe(no_mangle)]
 pub fn rust_main() -> ! {
     clear_bss();
-    logging::init();
-    info!("[kernel] Hello, world!");
+    println!("[kernel] Hello, world!");
     mm::init();
     mm::remap_test();
     trap::init();
diff --git a/os/src/mm/frame_allocator.rs b/os/src/mm/frame_allocator.rs
index 28b519c..f3d18ea 100644
--- a/os/src/mm/frame_allocator.rs
+++ b/os/src/mm/frame_allocator.rs
@@ -94,8 +94,8 @@ lazy_static! {
 }
 /// initiate the frame allocator using `ekernel` and `MEMORY_END`
 pub fn init_frame_allocator() {
-    unsafe extern "C" {
-        safe fn ekernel();
+    extern "C" {
+        fn ekernel();
     }
     FRAME_ALLOCATOR.exclusive_access().init(
         PhysAddr::from(ekernel as usize).ceil(),
diff --git a/os/src/mm/heap_allocator.rs b/os/src/mm/heap_allocator.rs
index a6b413b..e5f8b30 100644
--- a/os/src/mm/heap_allocator.rs
+++ b/os/src/mm/heap_allocator.rs
@@ -1,7 +1,6 @@
 //! The global allocator
 use crate::config::KERNEL_HEAP_SIZE;
 use buddy_system_allocator::LockedHeap;
-use core::ptr::addr_of_mut;
 
 #[global_allocator]
 /// heap allocator instance
@@ -19,7 +18,7 @@ pub fn init_heap() {
     unsafe {
         HEAP_ALLOCATOR
             .lock()
-            .init(addr_of_mut!(HEAP_SPACE) as usize, KERNEL_HEAP_SIZE);
+            .init(HEAP_SPACE.as_ptr() as usize, KERNEL_HEAP_SIZE);
     }
 }
 
@@ -27,9 +26,9 @@ pub fn init_heap() {
 pub fn heap_test() {
     use alloc::boxed::Box;
     use alloc::vec::Vec;
-    unsafe extern "C" {
-        safe fn sbss();
-        safe fn ebss();
+    extern "C" {
+        fn sbss();
+        fn ebss();
     }
     let bss_range = sbss as usize..ebss as usize;
     let a = Box::new(5);
diff --git a/os/src/mm/memory_set.rs b/os/src/mm/memory_set.rs
index b1e5072..a2c31cd 100644
--- a/os/src/mm/memory_set.rs
+++ b/os/src/mm/memory_set.rs
@@ -1,6 +1,5 @@
 //! Implementation of [`MapArea`] and [`MemorySet`].
-
-use super::{FrameTracker, frame_alloc};
+use super::{frame_alloc, FrameTracker};
 use super::{PTEFlags, PageTable, PageTableEntry};
 use super::{PhysAddr, PhysPageNum, VirtAddr, VirtPageNum};
 use super::{StepByOne, VPNRange};
@@ -13,17 +12,17 @@ use core::arch::asm;
 use lazy_static::*;
 use riscv::register::satp;
 
-unsafe extern "C" {
-    safe fn stext();
-    safe fn etext();
-    safe fn srodata();
-    safe fn erodata();
-    safe fn sdata();
-    safe fn edata();
-    safe fn sbss_with_stack();
-    safe fn ebss();
-    safe fn ekernel();
-    safe fn strampoline();
+extern "C" {
+    fn stext();
+    fn etext();
+    fn srodata();
+    fn erodata();
+    fn sdata();
+    fn edata();
+    fn sbss_with_stack();
+    fn ebss();
+    fn ekernel();
+    fn strampoline();
 }
 
 lazy_static! {
@@ -390,26 +389,20 @@ pub fn remap_test() {
     let mid_text: VirtAddr = ((stext as usize + etext as usize) / 2).into();
     let mid_rodata: VirtAddr = ((srodata as usize + erodata as usize) / 2).into();
     let mid_data: VirtAddr = ((sdata as usize + edata as usize) / 2).into();
-    assert!(
-        !kernel_space
-            .page_table
-            .translate(mid_text.floor())
-            .unwrap()
-            .writable(),
-    );
-    assert!(
-        !kernel_space
-            .page_table
-            .translate(mid_rodata.floor())
-            .unwrap()
-            .writable(),
-    );
-    assert!(
-        !kernel_space
-            .page_table
-            .translate(mid_data.floor())
-            .unwrap()
-            .executable(),
-    );
+    assert!(!kernel_space
+        .page_table
+        .translate(mid_text.floor())
+        .unwrap()
+        .writable(),);
+    assert!(!kernel_space
+        .page_table
+        .translate(mid_rodata.floor())
+        .unwrap()
+        .writable(),);
+    assert!(!kernel_space
+        .page_table
+        .translate(mid_data.floor())
+        .unwrap()
+        .executable(),);
     println!("remap_test passed!");
 }
diff --git a/os/src/mm/mod.rs b/os/src/mm/mod.rs
index 3255725..65f1e9a 100644
--- a/os/src/mm/mod.rs
+++ b/os/src/mm/mod.rs
@@ -13,13 +13,13 @@ mod page_table;
 
 use address::VPNRange;
 pub use address::{PhysAddr, PhysPageNum, StepByOne, VirtAddr, VirtPageNum};
-pub use frame_allocator::{FrameTracker, frame_alloc, frame_dealloc};
+pub use frame_allocator::{frame_alloc, frame_dealloc, FrameTracker};
 pub use memory_set::remap_test;
-pub use memory_set::{KERNEL_SPACE, MapPermission, MemorySet, kernel_token};
+pub use memory_set::{kernel_token, MapPermission, MemorySet, KERNEL_SPACE};
 use page_table::PTEFlags;
 pub use page_table::{
-    PageTable, PageTableEntry, UserBuffer, UserBufferIterator, translated_byte_buffer,
-    translated_ref, translated_refmut, translated_str,
+    translated_byte_buffer, translated_ref, translated_refmut, translated_str, PageTable,
+    PageTableEntry, UserBuffer, UserBufferIterator,
 };
 /// initiate heap allocator, frame allocator and kernel space
 pub fn init() {
diff --git a/os/src/mm/page_table.rs b/os/src/mm/page_table.rs
index f5fdf2b..9fbd21b 100644
--- a/os/src/mm/page_table.rs
+++ b/os/src/mm/page_table.rs
@@ -1,6 +1,5 @@
 //! Implementation of [`PageTableEntry`] and [`PageTable`].
-
-use super::{FrameTracker, PhysAddr, PhysPageNum, StepByOne, VirtAddr, VirtPageNum, frame_alloc};
+use super::{frame_alloc, FrameTracker, PhysAddr, PhysPageNum, StepByOne, VirtAddr, VirtPageNum};
 use alloc::string::String;
 use alloc::vec;
 use alloc::vec::Vec;
diff --git a/os/src/sbi.rs b/os/src/sbi.rs
index a73476f..eb79f67 100644
--- a/os/src/sbi.rs
+++ b/os/src/sbi.rs
@@ -20,7 +20,7 @@ pub fn set_timer(timer: usize) {
 
 /// use sbi call to shutdown the kernel
 pub fn shutdown(failure: bool) -> ! {
-    use sbi_rt::{NoReason, Shutdown, SystemFailure, system_reset};
+    use sbi_rt::{system_reset, NoReason, Shutdown, SystemFailure};
     if !failure {
         system_reset(Shutdown, NoReason);
     } else {
diff --git a/os/src/syscall/fs.rs b/os/src/syscall/fs.rs
index 8d46fad..aecc790 100644
--- a/os/src/syscall/fs.rs
+++ b/os/src/syscall/fs.rs
@@ -1,6 +1,6 @@
 //! File and filesystem-related syscalls
-use crate::fs::{OpenFlags, open_file};
-use crate::mm::{UserBuffer, translated_byte_buffer, translated_str};
+use crate::fs::{open_file, OpenFlags};
+use crate::mm::{translated_byte_buffer, translated_str, UserBuffer};
 use crate::task::{current_task, current_user_token};
 
 pub fn sys_write(fd: usize, buf: *const u8, len: usize) -> isize {
@@ -47,13 +47,6 @@ pub fn sys_open(path: *const u8, flags: u32) -> isize {
     let task = current_task().unwrap();
     let token = current_user_token();
     let path = translated_str(token, path);
-
-    // 简单用户检查示例：非 root 用户不能打开 /root 下文件
-    let username = task.inner_exclusive_access().user.clone();
-    if path.starts_with("/root") && username != "root" {
-        return -1; // Permission denied
-    }
-
     if let Some(inode) = open_file(path.as_str(), OpenFlags::from_bits(flags).unwrap()) {
         let mut inner = task.inner_exclusive_access();
         let fd = inner.alloc_fd();
@@ -64,7 +57,6 @@ pub fn sys_open(path: *const u8, flags: u32) -> isize {
     }
 }
 
-
 pub fn sys_close(fd: usize) -> isize {
     let task = current_task().unwrap();
     let mut inner = task.inner_exclusive_access();
diff --git a/os/src/syscall/process.rs b/os/src/syscall/process.rs
index 61e78d6..3d62cbb 100644
--- a/os/src/syscall/process.rs
+++ b/os/src/syscall/process.rs
@@ -1,4 +1,4 @@
-use crate::fs::{OpenFlags, open_file};
+use crate::fs::{open_file, OpenFlags};
 use crate::mm::{translated_refmut, translated_str};
 use crate::task::{
     add_task, current_task, current_user_token, exit_current_and_run_next,
diff --git a/os/src/task/mod.rs b/os/src/task/mod.rs
index 47c13cd..e4837cb 100644
--- a/os/src/task/mod.rs
+++ b/os/src/task/mod.rs
@@ -23,20 +23,20 @@ mod switch;
 #[allow(rustdoc::private_intra_doc_links)]
 mod task;
 
-use crate::fs::{OpenFlags, open_file};
+use crate::fs::{open_file, OpenFlags};
 use crate::sbi::shutdown;
 use alloc::sync::Arc;
 pub use context::TaskContext;
 use lazy_static::*;
-pub use manager::{TaskManager, fetch_task};
+pub use manager::{fetch_task, TaskManager};
 use switch::__switch;
 use task::{TaskControlBlock, TaskStatus};
 
 pub use manager::add_task;
-pub use pid::{KernelStack, PidAllocator, PidHandle, pid_alloc};
+pub use pid::{pid_alloc, KernelStack, PidAllocator, PidHandle};
 pub use processor::{
-    Processor, current_task, current_trap_cx, current_user_token, run_tasks, schedule,
-    take_current_task,
+    current_task, current_trap_cx, current_user_token, run_tasks, schedule, take_current_task,
+    Processor,
 };
 /// Suspend the current 'Running' task and run the next task in task list.
 pub fn suspend_current_and_run_next() {
diff --git a/os/src/task/pid.rs b/os/src/task/pid.rs
index f0a5e2a..a7bdea9 100644
--- a/os/src/task/pid.rs
+++ b/os/src/task/pid.rs
@@ -1,6 +1,6 @@
 //!Implementation of [`PidAllocator`]
 use crate::config::{KERNEL_STACK_SIZE, PAGE_SIZE, TRAMPOLINE};
-use crate::mm::{KERNEL_SPACE, MapPermission, VirtAddr};
+use crate::mm::{MapPermission, VirtAddr, KERNEL_SPACE};
 use crate::sync::UPSafeCell;
 use alloc::vec::Vec;
 use lazy_static::*;
diff --git a/os/src/task/processor.rs b/os/src/task/processor.rs
index 7c05a21..1d9c0f2 100644
--- a/os/src/task/processor.rs
+++ b/os/src/task/processor.rs
@@ -1,7 +1,7 @@
 //!Implementation of [`Processor`] and Intersection of control flow
 use super::__switch;
+use super::{fetch_task, TaskStatus};
 use super::{TaskContext, TaskControlBlock};
-use super::{TaskStatus, fetch_task};
 use crate::sync::UPSafeCell;
 use crate::trap::TrapContext;
 use alloc::sync::Arc;
diff --git a/os/src/task/switch.rs b/os/src/task/switch.rs
index 8f69fdf..7d194f5 100644
--- a/os/src/task/switch.rs
+++ b/os/src/task/switch.rs
@@ -4,11 +4,6 @@ use core::arch::global_asm;
 
 global_asm!(include_str!("switch.S"));
 
-unsafe extern "C" {
-    /// Switch to the context of `next_task_cx_ptr`, saving the current context
-    /// in `current_task_cx_ptr`.
-    pub unsafe fn __switch(
-        current_task_cx_ptr: *mut TaskContext,
-        next_task_cx_ptr: *const TaskContext,
-    );
+extern "C" {
+    pub fn __switch(current_task_cx_ptr: *mut TaskContext, next_task_cx_ptr: *const TaskContext);
 }
diff --git a/os/src/task/task.rs b/os/src/task/task.rs
index 87d287a..6e38b92 100644
--- a/os/src/task/task.rs
+++ b/os/src/task/task.rs
@@ -1,11 +1,11 @@
 //!Implementation of [`TaskControlBlock`]
 use super::TaskContext;
-use super::{KernelStack, PidHandle, pid_alloc};
+use super::{pid_alloc, KernelStack, PidHandle};
 use crate::config::TRAP_CONTEXT;
 use crate::fs::{File, Stdin, Stdout};
-use crate::mm::{KERNEL_SPACE, MemorySet, PhysPageNum, VirtAddr};
+use crate::mm::{MemorySet, PhysPageNum, VirtAddr, KERNEL_SPACE};
 use crate::sync::UPSafeCell;
-use crate::trap::{TrapContext, trap_handler};
+use crate::trap::{trap_handler, TrapContext};
 use alloc::sync::{Arc, Weak};
 use alloc::vec;
 use alloc::vec::Vec;
@@ -30,9 +30,6 @@ pub struct TaskControlBlockInner {
     pub children: Vec<Arc<TaskControlBlock>>,
     pub exit_code: i32,
     pub fd_table: Vec<Option<Arc<dyn File + Send + Sync>>>,
-    
-    // New: User
-    pub user: String,
 }
 
 impl TaskControlBlockInner {
@@ -169,7 +166,6 @@ impl TaskControlBlock {
                     children: Vec::new(),
                     exit_code: 0,
                     fd_table: new_fd_table,
-                    user: username.to_string(),  // Init User name
                 })
             },
         });
diff --git a/os/src/trap/context.rs b/os/src/trap/context.rs
index 5f968e5..0cae492 100644
--- a/os/src/trap/context.rs
+++ b/os/src/trap/context.rs
@@ -1,5 +1,5 @@
 //! Implementation of [`TrapContext`]
-use riscv::register::sstatus::{self, SPP, Sstatus};
+use riscv::register::sstatus::{self, Sstatus, SPP};
 
 #[repr(C)]
 #[derive(Debug)]
diff --git a/os/src/trap/mod.rs b/os/src/trap/mod.rs
index 26e7895..49b85ec 100644
--- a/os/src/trap/mod.rs
+++ b/os/src/trap/mod.rs
@@ -50,7 +50,7 @@ pub fn enable_timer_interrupt() {
     }
 }
 
-#[unsafe(no_mangle)]
+#[no_mangle]
 /// handle an interrupt, exception, or system call from user space
 pub fn trap_handler() -> ! {
     set_kernel_trap_entry();
@@ -103,7 +103,7 @@ pub fn trap_handler() -> ! {
     trap_return();
 }
 
-#[unsafe(no_mangle)]
+#[no_mangle]
 /// set the new addr of __restore asm function in TRAMPOLINE page,
 /// set the reg a0 = trap_cx_ptr, reg a1 = phy addr of usr page table,
 /// finally, jump to new addr of __restore asm function
@@ -111,9 +111,9 @@ pub fn trap_return() -> ! {
     set_user_trap_entry();
     let trap_cx_ptr = TRAP_CONTEXT;
     let user_satp = current_user_token();
-    unsafe extern "C" {
-        unsafe fn __alltraps();
-        unsafe fn __restore();
+    extern "C" {
+        fn __alltraps();
+        fn __restore();
     }
     let restore_va = __restore as usize - __alltraps as usize + TRAMPOLINE;
     unsafe {
@@ -128,7 +128,7 @@ pub fn trap_return() -> ! {
     }
 }
 
-#[unsafe(no_mangle)]
+#[no_mangle]
 /// Unimplement: traps/interrupts/exceptions from kernel mode
 /// Todo: Chapter 9: I/O device
 pub fn trap_from_kernel() -> ! {
diff --git a/rust-toolchain.toml b/rust-toolchain.toml
index e6f10a1..c65d258 100644
--- a/rust-toolchain.toml
+++ b/rust-toolchain.toml
@@ -1,6 +1,6 @@
 [toolchain]
 profile = "minimal"
 # use the nightly version of the last stable toolchain, see <https://forge.rust-lang.org/>
-channel = "nightly-2025-02-18"
+channel = "nightly-2024-05-01"
 components = ["rust-src", "llvm-tools", "rustfmt", "clippy"]
 targets = ["riscv64gc-unknown-none-elf"]
diff --git a/user/Cargo.toml b/user/Cargo.toml
index 92f3f7e..3bc82dc 100644
--- a/user/Cargo.toml
+++ b/user/Cargo.toml
@@ -2,7 +2,7 @@
 name = "user_lib"
 version = "0.1.0"
 authors = ["Yifan Wu <shinbokuow@163.com>"]
-edition = "2024"
+edition = "2018"
 
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
diff --git a/user/src/bin/cat_filea.rs b/user/src/bin/cat_filea.rs
index 20daf77..6307ecd 100644
--- a/user/src/bin/cat_filea.rs
+++ b/user/src/bin/cat_filea.rs
@@ -5,9 +5,9 @@
 extern crate user_lib;
 extern crate alloc;
 
-use user_lib::{OpenFlags, close, open, read};
+use user_lib::{close, open, read, OpenFlags};
 
-#[unsafe(no_mangle)]
+#[no_mangle]
 pub fn main() -> i32 {
     let fd = open("filea\0", OpenFlags::RDONLY);
     if fd == -1 {
diff --git a/user/src/bin/exit.rs b/user/src/bin/exit.rs
index 8e19542..60510c9 100644
--- a/user/src/bin/exit.rs
+++ b/user/src/bin/exit.rs
@@ -7,7 +7,7 @@ use user_lib::{exit, fork, wait, waitpid, yield_};
 
 const MAGIC: i32 = -0x10384;
 
-#[unsafe(no_mangle)]
+#[no_mangle]
 pub fn main() -> i32 {
     println!("I am the parent. Forking the child...");
     let pid = fork();
diff --git a/user/src/bin/fantastic_text.rs b/user/src/bin/fantastic_text.rs
index 0850162..a3402ff 100644
--- a/user/src/bin/fantastic_text.rs
+++ b/user/src/bin/fantastic_text.rs
@@ -5,12 +5,12 @@
 extern crate user_lib;
 
 macro_rules! color_text {
-    ($text:expr, $color:expr) => {
+    ($text:expr, $color:expr) => {{
         format_args!("\x1b[{}m{}\x1b[0m", $color, $text)
-    };
+    }};
 }
 
-#[unsafe(no_mangle)]
+#[no_mangle]
 pub fn main() -> i32 {
     println!(
         "{}{}{}{}{} {}{}{}{} {}{}{}{}{}{}",
diff --git a/user/src/bin/filetest_simple.rs b/user/src/bin/filetest_simple.rs
index b192156..3406d55 100644
--- a/user/src/bin/filetest_simple.rs
+++ b/user/src/bin/filetest_simple.rs
@@ -4,9 +4,9 @@
 #[macro_use]
 extern crate user_lib;
 
-use user_lib::{OpenFlags, close, open, read, write};
+use user_lib::{close, open, read, write, OpenFlags};
 
-#[unsafe(no_mangle)]
+#[no_mangle]
 pub fn main() -> i32 {
     let test_str = "Hello, world!";
     let filea = "filea\0";
diff --git a/user/src/bin/forktest.rs b/user/src/bin/forktest.rs
index f6003c5..5374a56 100644
--- a/user/src/bin/forktest.rs
+++ b/user/src/bin/forktest.rs
@@ -8,7 +8,7 @@ use user_lib::{exit, fork, wait};
 
 const MAX_CHILD: usize = 30;
 
-#[unsafe(no_mangle)]
+#[no_mangle]
 pub fn main() -> i32 {
     for i in 0..MAX_CHILD {
         let pid = fork();
diff --git a/user/src/bin/forktest2.rs b/user/src/bin/forktest2.rs
index ee452cc..c91ce15 100644
--- a/user/src/bin/forktest2.rs
+++ b/user/src/bin/forktest2.rs
@@ -8,7 +8,7 @@ use user_lib::{exit, fork, get_time, getpid, sleep, wait};
 
 static NUM: usize = 30;
 
-#[unsafe(no_mangle)]
+#[no_mangle]
 pub fn main() -> i32 {
     for _ in 0..NUM {
         let pid = fork();
diff --git a/user/src/bin/forktest_simple.rs b/user/src/bin/forktest_simple.rs
index b9cf587..29a624b 100644
--- a/user/src/bin/forktest_simple.rs
+++ b/user/src/bin/forktest_simple.rs
@@ -6,7 +6,7 @@ extern crate user_lib;
 
 use user_lib::{fork, getpid, wait};
 
-#[unsafe(no_mangle)]
+#[no_mangle]
 pub fn main() -> i32 {
     assert_eq!(wait(&mut 0i32), -1);
     println!("sys_wait without child process test passed!");
diff --git a/user/src/bin/forktree.rs b/user/src/bin/forktree.rs
index bcca4e6..bfcfc4c 100644
--- a/user/src/bin/forktree.rs
+++ b/user/src/bin/forktree.rs
@@ -29,7 +29,7 @@ fn fork_tree(cur: &str) {
     fork_child(cur, '1');
 }
 
-#[unsafe(no_mangle)]
+#[no_mangle]
 pub fn main() -> i32 {
     fork_tree("");
     sleep(3000);
diff --git a/user/src/bin/hello_world.rs b/user/src/bin/hello_world.rs
index cc651e7..10d3f26 100644
--- a/user/src/bin/hello_world.rs
+++ b/user/src/bin/hello_world.rs
@@ -4,7 +4,7 @@
 #[macro_use]
 extern crate user_lib;
 
-#[unsafe(no_mangle)]
+#[no_mangle]
 pub fn main() -> i32 {
     println!("Hello world from user mode program!");
     0
diff --git a/user/src/bin/huge_write.rs b/user/src/bin/huge_write.rs
index 9327261..e93f8b8 100644
--- a/user/src/bin/huge_write.rs
+++ b/user/src/bin/huge_write.rs
@@ -4,9 +4,9 @@
 #[macro_use]
 extern crate user_lib;
 
-use user_lib::{OpenFlags, close, get_time, open, write};
+use user_lib::{close, get_time, open, write, OpenFlags};
 
-#[unsafe(no_mangle)]
+#[no_mangle]
 pub fn main() -> i32 {
     let mut buffer = [0u8; 1024]; // 1KiB
     for (i, ch) in buffer.iter_mut().enumerate() {
diff --git a/user/src/bin/initproc.rs b/user/src/bin/initproc.rs
index d522b77..71bed27 100644
--- a/user/src/bin/initproc.rs
+++ b/user/src/bin/initproc.rs
@@ -6,7 +6,7 @@ extern crate user_lib;
 
 use user_lib::{exec, fork, wait, yield_};
 
-#[unsafe(no_mangle)]
+#[no_mangle]
 fn main() -> i32 {
     if fork() == 0 {
         exec("user_shell\0");
diff --git a/user/src/bin/matrix.rs b/user/src/bin/matrix.rs
index 846f4c6..9ebf48f 100644
--- a/user/src/bin/matrix.rs
+++ b/user/src/bin/matrix.rs
@@ -44,7 +44,7 @@ fn work(times: isize) {
     exit(0);
 }
 
-#[unsafe(no_mangle)]
+#[no_mangle]
 pub fn main() -> i32 {
     for _ in 0..NUM {
         let pid = fork();
diff --git a/user/src/bin/sleep.rs b/user/src/bin/sleep.rs
index e02b3ed..641a4f9 100644
--- a/user/src/bin/sleep.rs
+++ b/user/src/bin/sleep.rs
@@ -15,7 +15,7 @@ fn sleepy() {
     exit(0);
 }
 
-#[unsafe(no_mangle)]
+#[no_mangle]
 pub fn main() -> i32 {
     let current_time = get_time();
     let pid = fork();
diff --git a/user/src/bin/sleep_simple.rs b/user/src/bin/sleep_simple.rs
index 9f6e2e4..7015a3d 100644
--- a/user/src/bin/sleep_simple.rs
+++ b/user/src/bin/sleep_simple.rs
@@ -6,7 +6,7 @@ extern crate user_lib;
 
 use user_lib::{get_time, sleep};
 
-#[unsafe(no_mangle)]
+#[no_mangle]
 pub fn main() -> i32 {
     println!("into sleep test!");
     let start = get_time();
diff --git a/user/src/bin/stack_overflow.rs b/user/src/bin/stack_overflow.rs
index 731982a..3bec557 100644
--- a/user/src/bin/stack_overflow.rs
+++ b/user/src/bin/stack_overflow.rs
@@ -12,7 +12,7 @@ fn f(depth: usize) {
     f(depth + 1);
 }
 
-#[unsafe(no_mangle)]
+#[no_mangle]
 pub fn main() -> i32 {
     println!("It should trigger segmentation fault!");
     f(0);
diff --git a/user/src/bin/user_shell.rs b/user/src/bin/user_shell.rs
index 1ca120b..cdcb972 100644
--- a/user/src/bin/user_shell.rs
+++ b/user/src/bin/user_shell.rs
@@ -16,7 +16,7 @@ use alloc::string::String;
 use user_lib::console::getchar;
 use user_lib::{exec, fork, waitpid};
 
-#[unsafe(no_mangle)]
+#[no_mangle]
 pub fn main() -> i32 {
     println!("Rust user shell");
     let mut line: String = String::new();
diff --git a/user/src/bin/usertests.rs b/user/src/bin/usertests.rs
index d47dc20..20cbbe9 100644
--- a/user/src/bin/usertests.rs
+++ b/user/src/bin/usertests.rs
@@ -84,7 +84,7 @@ fn run_tests(tests: &[(&str, &str, &str, &str, i32)]) -> i32 {
     pass_num
 }
 
-#[unsafe(no_mangle)]
+#[no_mangle]
 pub fn main() -> i32 {
     let succ_num = run_tests(SUCC_TESTS);
     let err_num = run_tests(FAIL_TESTS);
diff --git a/user/src/bin/usertests_simple.rs b/user/src/bin/usertests_simple.rs
index 0a73edd..62bc838 100644
--- a/user/src/bin/usertests_simple.rs
+++ b/user/src/bin/usertests_simple.rs
@@ -20,7 +20,7 @@ static TESTS: &[&str] = &[
 
 use user_lib::{exec, fork, waitpid};
 
-#[unsafe(no_mangle)]
+#[no_mangle]
 pub fn main() -> i32 {
     for test in TESTS {
         println!("Usertests: Running {}", test);
diff --git a/user/src/bin/yield.rs b/user/src/bin/yield.rs
index b9558ef..78b1468 100644
--- a/user/src/bin/yield.rs
+++ b/user/src/bin/yield.rs
@@ -5,7 +5,7 @@
 extern crate user_lib;
 use user_lib::{getpid, yield_};
 
-#[unsafe(no_mangle)]
+#[no_mangle]
 pub fn main() -> i32 {
     println!("Hello, I am process {}.", getpid());
     for i in 0..5 {
diff --git a/user/src/lang_items.rs b/user/src/lang_items.rs
index b03e8eb..c65aa42 100644
--- a/user/src/lang_items.rs
+++ b/user/src/lang_items.rs
@@ -2,7 +2,7 @@ use super::exit;
 
 #[panic_handler]
 fn panic_handler(panic_info: &core::panic::PanicInfo) -> ! {
-    let err = panic_info.message();
+    let err = panic_info.message().unwrap();
     if let Some(location) = panic_info.location() {
         println!(
             "Panicked at {}:{}, {}",
diff --git a/user/src/lib.rs b/user/src/lib.rs
index a5584c2..c3b2cb9 100644
--- a/user/src/lib.rs
+++ b/user/src/lib.rs
@@ -1,5 +1,6 @@
 #![no_std]
 #![feature(linkage)]
+#![feature(panic_info_message)]
 #![feature(alloc_error_handler)]
 
 #[macro_use]
@@ -12,7 +13,6 @@ extern crate alloc;
 extern crate bitflags;
 
 use buddy_system_allocator::LockedHeap;
-use core::ptr::addr_of_mut;
 use syscall::*;
 
 const USER_HEAP_SIZE: usize = 32768;
@@ -27,18 +27,18 @@ pub fn handle_alloc_error(layout: core::alloc::Layout) -> ! {
     panic!("Heap allocation error, layout = {:?}", layout);
 }
 
-#[unsafe(no_mangle)]
-#[unsafe(link_section = ".text.entry")]
+#[no_mangle]
+#[link_section = ".text.entry"]
 pub extern "C" fn _start() -> ! {
     unsafe {
         HEAP.lock()
-            .init(addr_of_mut!(HEAP_SPACE) as usize, USER_HEAP_SIZE);
+            .init(HEAP_SPACE.as_ptr() as usize, USER_HEAP_SIZE);
     }
     exit(main());
 }
 
 #[linkage = "weak"]
-#[unsafe(no_mangle)]
+#[no_mangle]
 fn main() -> i32 {
     panic!("Cannot find main!");
 }