Fix multiple issues pointed out by the new compiler

Cargo.lock

@@ -655,9 +655,9 @@ checksum = "6fb8d784f27acf97159b40fc4db5ecd8aa23b9ad5ef69cdd136d3bc80665f0c0"
 
 [[package]]
 name = "gimli"
-version = "0.30.0"
+version = "0.31.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "e2e1d97fbe9722ba9bbd0c97051c2956e726562b61f86a25a4360398a40edfc9"
+checksum = "07e28edb80900c19c28f1072f2e8aeca7fa06b23cd4169cefe1af5aa3260783f"
 
 [[package]]
 name = "hash32"
@@ -1668,11 +1668,11 @@ checksum = "229730647fbc343e3a80e463c1db7f78f3855d3f3739bee0dda773c9a037c90a"
 
 [[package]]
 name = "unwinding"
-version = "0.2.2"
+version = "0.2.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "dc55842d0db6329a669d55a623c674b02d677b16bfb2d24857d4089d41eba882"
+checksum = "637d511437df708cee34bdec7ba2f1548d256b7acf3ff20e0a1c559f9bf3a987"
 dependencies = [
- "gimli 0.30.0",
+ "gimli 0.31.1",
 ]
 
 [[package]]

kernel/comps/network/src/driver.rs

@@ -48,7 +48,7 @@ impl device::RxToken for RxToken {
 
 pub struct TxToken<'a>(&'a mut dyn AnyNetworkDevice);
 
-impl<'a> device::TxToken for TxToken<'a> {
+impl device::TxToken for TxToken<'_> {
     fn consume<R, F>(self, len: usize, f: F) -> R
     where
         F: FnOnce(&mut [u8]) -> R,

kernel/comps/time/src/clocksource.rs

@@ -166,9 +166,12 @@ impl ClockSource {
     }
 }
 
-/// `Instant` captures a specific moment, storing the duration of time
+/// A specific moment.
+///
+/// [`Instant`] captures a specific moment, storing the duration of time
 /// elapsed since a reference point (typically the system boot time).
-/// The `Instant` is expressed in seconds and the fractional part is expressed in nanoseconds.
+/// The [`Instant`] is expressed in seconds and the fractional part is
+/// expressed in nanoseconds.
 #[derive(Debug, Default, Copy, Clone)]
 pub struct Instant {
     secs: u64,

kernel/libs/aster-bigtcp/src/iface/phy/ether.rs

@@ -162,9 +162,9 @@ impl<D, E> EtherIface<D, E> {
                 }
 
                 // Ignore the ARP packet if we do not own the target address.
-                if !iface_cx
+                if iface_cx
                     .ipv4_addr()
-                    .is_some_and(|addr| addr == *target_protocol_addr)
+                    .is_none_or(|addr| addr != *target_protocol_addr)
                 {
                     return None;
                 }

kernel/libs/aster-bigtcp/src/iface/poll.rs

@@ -44,7 +44,7 @@ impl<'a, E> PollContext<'a, E> {
 pub(super) trait FnHelper<A, B, C, O>: FnMut(A, B, C) -> O {}
 impl<A, B, C, O, F> FnHelper<A, B, C, O> for F where F: FnMut(A, B, C) -> O {}
 
-impl<'a, E> PollContext<'a, E> {
+impl<E> PollContext<'_, E> {
     pub(super) fn poll_ingress<D, P, Q>(
         &mut self,
         device: &mut D,
@@ -280,7 +280,7 @@ impl<'a, E> PollContext<'a, E> {
     }
 }
 
-impl<'a, E> PollContext<'a, E> {
+impl<E> PollContext<'_, E> {
     pub(super) fn poll_egress<D, Q>(&mut self, device: &mut D, mut dispatch_phy: Q)
     where
         D: Device + ?Sized,

kernel/libs/aster-util/src/safe_ptr.rs

@@ -368,7 +368,7 @@ impl<T, R> SafePtr<T, DmaStream, R> {
 }
 
 #[inherit_methods(from = "(*self)")]
-impl<'a, T, R> SafePtr<T, &'a DmaStream, R> {
+impl<T, R> SafePtr<T, &DmaStream, R> {
     pub fn sync(&self) -> Result<()>;
 }
 

kernel/libs/typeflags-util/src/extend.rs

@@ -3,6 +3,7 @@
 use crate::{Cons, Nil};
 
 /// This trait will extend a set with another item.
+///
 /// If the set already contains the item, it will return the original set.
 /// Otherwise, it will return the new set with the new item.
 /// The implementation should care about the item orders when extending set.

kernel/src/context.rs

@@ -159,15 +159,19 @@ impl<'a> CurrentUserSpace<'a> {
     }
 }
 
-/// A trait providing the ability to read a C string from the user space
-/// of the current process specifically for [`VmReader<'_, UserSpace>`], which
-/// should reading the bytes iteratively in the reader until encountering
-/// the end of the reader or reading a `\0` (is also included into the final C String).
+/// A trait providing the ability to read a C string from the user space.
+///
+/// The user space should be of the current process. The implemented method
+/// should read the bytes iteratively in the reader ([`VmReader`]) until
+/// encountering the end of the reader or reading a `\0` (which is also
+/// included in the final C String).
 pub trait ReadCString {
     fn read_cstring(&mut self) -> Result<CString>;
 }
 
-impl<'a> ReadCString for VmReader<'a, Fallible> {
+impl ReadCString for VmReader<'_, Fallible> {
+    /// Reads a C string from the user space.
+    ///
     /// This implementation is inspired by
     /// the `do_strncpy_from_user` function in Linux kernel.
     /// The original Linux implementation can be found at:

kernel/src/device/tty/line_discipline.rs

@@ -240,7 +240,7 @@ impl LineDiscipline {
             b'\r' => echo_callback("\r\n"),
             ch if ch == *termios.get_special_char(CC_C_CHAR::VERASE) => {
                 // write a space to overwrite current character
-                let backspace: &str = core::str::from_utf8(&[b'\x08', b' ', b'\x08']).unwrap();
+                let backspace: &str = core::str::from_utf8(b"\x08 \x08").unwrap();
                 echo_callback(backspace);
             }
             ch if is_printable_char(ch) => print!("{}", char::from(ch)),

kernel/src/fs/exfat/dentry.rs

@@ -403,8 +403,8 @@ impl ExfatDentrySet {
         }
         Ok(name)
     }
-    /// Name dentries are not permitted to modify. We should create a new dentry set for renaming.
 
+    /// Name dentries are not permitted to modify. We should create a new dentry set for renaming.
     fn calculate_checksum(&self) -> u16 {
         const CHECKSUM_BYTES_RANGE: Range<usize> = 2..4;
         const EMPTY_RANGE: Range<usize> = 0..0;
@@ -502,7 +502,6 @@ impl Iterator for ExfatDentryIterator {
 }
 
 /// On-disk dentry formats
-
 #[repr(C, packed)]
 #[derive(Clone, Debug, Default, Copy, Pod)]
 // For files & directories

kernel/src/fs/exfat/inode.rs

@@ -891,7 +891,7 @@ impl ExfatInode {
         // TODO: remove trailing periods of pathname.
         // Do not allow creation of files with names ending with period(s).
 
-        let name_dentries = (name.len() + EXFAT_FILE_NAME_LEN - 1) / EXFAT_FILE_NAME_LEN;
+        let name_dentries = name.len().div_ceil(EXFAT_FILE_NAME_LEN);
         let num_dentries = name_dentries + 2; // FILE Entry + Stream Entry + Name Entry
 
         // We update the size of inode before writing page_cache, but it is fine since we've cleaned the page_cache.
@@ -1139,7 +1139,7 @@ impl Inode for ExfatInode {
             ino: inner.ino,
             size: inner.size,
             blk_size,
-            blocks: (inner.size + blk_size - 1) / blk_size,
+            blocks: inner.size.div_ceil(blk_size),
             atime: inner.atime.as_duration().unwrap_or_default(),
             mtime: inner.mtime.as_duration().unwrap_or_default(),
             ctime: inner.ctime.as_duration().unwrap_or_default(),

kernel/src/fs/exfat/mod.rs

@@ -698,7 +698,7 @@ mod test {
         }
 
         let steps = 7;
-        let write_len = (BUF_SIZE + steps - 1) / steps;
+        let write_len = BUF_SIZE.div_ceil(steps);
         for i in 0..steps {
             let start = i * write_len;
             let end = BUF_SIZE.min(start + write_len);

kernel/src/fs/exfat/utils.rs

@@ -14,7 +14,7 @@ pub fn make_hash_index(cluster: ClusterID, offset: u32) -> usize {
 pub fn calc_checksum_32(data: &[u8]) -> u32 {
     let mut checksum: u32 = 0;
     for &value in data {
-        checksum = ((checksum << 31) | (checksum >> 1)).wrapping_add(value as u32);
+        checksum = checksum.rotate_right(1).wrapping_add(value as u32);
     }
     checksum
 }
@@ -27,7 +27,7 @@ pub fn calc_checksum_16(data: &[u8], ignore: core::ops::Range<usize>, prev_check
         if ignore.contains(&pos) {
             continue;
         }
-        result = ((result << 15) | (result >> 1)).wrapping_add(value as u16);
+        result = result.rotate_right(1).wrapping_add(value as u16);
     }
     result
 }

kernel/src/fs/ext2/dir.rs

@@ -192,7 +192,7 @@ impl<'a> DirEntryReader<'a> {
     }
 }
 
-impl<'a> Iterator for DirEntryReader<'a> {
+impl Iterator for DirEntryReader<'_> {
     type Item = (usize, DirEntry);
 
     fn next(&mut self) -> Option<Self::Item> {

kernel/src/fs/ext2/inode.rs

@@ -1761,7 +1761,7 @@ impl<'a> DeviceRangeReader<'a> {
     }
 }
 
-impl<'a> Iterator for DeviceRangeReader<'a> {
+impl Iterator for DeviceRangeReader<'_> {
     type Item = Range<Ext2Bid>;
 
     fn next(&mut self) -> Option<Self::Item> {

kernel/src/fs/fs_resolver.rs

@@ -491,7 +491,7 @@ impl<'a> FsPath<'a> {
 impl<'a> TryFrom<&'a str> for FsPath<'a> {
     type Error = crate::error::Error;
 
-    fn try_from(path: &'a str) -> Result<FsPath> {
+    fn try_from(path: &'a str) -> Result<FsPath<'a>> {
         if path.is_empty() {
             return_errno_with_message!(Errno::ENOENT, "path is an empty string");
         }

kernel/src/fs/procfs/sys/kernel/mod.rs

@@ -15,7 +15,6 @@ use crate::{
 mod cap_last_cap;
 
 /// Represents the inode at `/proc/sys/kernel`.
-
 pub struct KernelDirOps;
 
 impl KernelDirOps {

kernel/src/fs/utils/inode.rs

@@ -502,7 +502,7 @@ pub struct InodeWriter<'a> {
     offset: usize,
 }
 
-impl<'a> Write for InodeWriter<'a> {
+impl Write for InodeWriter<'_> {
     #[inline]
     fn write(&mut self, buf: &[u8]) -> IoResult<usize> {
         let mut reader = VmReader::from(buf).to_fallible();

kernel/src/fs/utils/range_lock/range.rs

@@ -6,6 +6,7 @@ use super::*;
 pub const OFFSET_MAX: usize = i64::MAX as usize;
 
 /// A range in a file.
+///
 /// The range is [start, end).
 /// The range is valid if start < end.
 /// The range is empty if start == end.

kernel/src/lib.rs

@@ -14,7 +14,6 @@
 #![feature(fn_traits)]
 #![feature(format_args_nl)]
 #![feature(int_roundings)]
-#![feature(iter_repeat_n)]
 #![feature(let_chains)]
 #![feature(linkage)]
 #![feature(linked_list_remove)]

kernel/src/net/socket/ip/datagram/bound.rs

@@ -74,9 +74,8 @@ impl BoundDatagram {
                 // But current smoltcp API seems not to support this behavior.
                 reader
                     .read(&mut VmWriter::from(socket_buffer))
-                    .map_err(|e| {
-                        warn!("unexpected UDP packet will be sent");
-                        e
+                    .inspect_err(|e| {
+                        warn!("unexpected UDP packet {e:#?} will be sent");
                     })
             });
 

kernel/src/process/credentials/credentials_.rs

@@ -34,8 +34,8 @@ pub(super) struct Credentials_ {
     supplementary_gids: RwLock<BTreeSet<Gid>>,
 
     /// The Linux capabilities.
+    ///
     /// This is not the capability (in static_cap.rs) enforced on rust objects.
-
     /// Capability that child processes can inherit
     inheritable_capset: AtomicCapSet,
 

kernel/src/process/posix_thread/robust_list.rs

@@ -84,7 +84,7 @@ impl<'a> FutexIter<'a> {
 
 const ROBUST_LIST_LIMIT: isize = 2048;
 
-impl<'a> Iterator for FutexIter<'a> {
+impl Iterator for FutexIter<'_> {
     type Item = Vaddr;
 
     fn next(&mut self) -> Option<Self::Item> {

kernel/src/process/process/process_group.rs

@@ -108,7 +108,7 @@ pub struct ProcessGroupGuard<'a> {
     inner: MutexGuard<'a, Inner>,
 }
 
-impl<'a> ProcessGroupGuard<'a> {
+impl ProcessGroupGuard<'_> {
     /// Returns an iterator over the processes in the group.
     pub fn iter(&self) -> ProcessGroupIter {
         ProcessGroupIter {

kernel/src/process/process_table.rs

@@ -44,7 +44,7 @@ pub struct ProcessTable<'a> {
     inner: MutexGuard<'a, BTreeMap<Pid, Arc<Process>>>,
 }
 
-impl<'a> ProcessTable<'a> {
+impl ProcessTable<'_> {
     /// Returns an iterator over the processes in the table.
     pub fn iter(&self) -> ProcessTableIter {
         ProcessTableIter {

kernel/src/process/process_vm/init_stack/aux_vec.rs

@@ -14,7 +14,6 @@ use crate::prelude::*;
 ///  > about the environment in which it is operating. The form of this information
 ///  > is a table of key-value pairs, where the keys are from the set of ‘AT_’
 ///  > values in elf.h.
-
 #[allow(non_camel_case_types)]
 #[derive(Clone, Copy, Debug, PartialEq, Eq, Hash, PartialOrd, Ord)]
 #[repr(u8)]

kernel/src/process/program_loader/elf/load_elf.rs

@@ -338,11 +338,7 @@ fn map_segment_vmo(
     vm_map_options = vm_map_options.offset(offset).handle_page_faults_around();
     let map_addr = vm_map_options.build()?;
 
-    let anonymous_map_size: usize = if total_map_size > segment_size {
-        total_map_size - segment_size
-    } else {
-        0
-    };
+    let anonymous_map_size: usize = total_map_size.saturating_sub(segment_size);
 
     if anonymous_map_size > 0 {
         let mut anonymous_map_options = root_vmar

kernel/src/syscall/getdents64.rs

@@ -104,7 +104,7 @@ impl<'a, T: DirentSerializer> DirentBufferReader<'a, T> {
     }
 }
 
-impl<'a, T: DirentSerializer> DirentVisitor for DirentBufferReader<'a, T> {
+impl<T: DirentSerializer> DirentVisitor for DirentBufferReader<'_, T> {
     fn visit(&mut self, name: &str, ino: u64, type_: InodeType, offset: usize) -> Result<()> {
         let dirent_serializer = T::new(ino, offset as u64, type_, CString::new(name)?);
         if self.read_len >= self.buffer.len() {

kernel/src/syscall/mmap.rs

@@ -218,6 +218,7 @@ impl MMapOptions {
         self.typ
     }
 
+    #[allow(unused)]
     pub fn flags(&self) -> MMapFlags {
         self.flags
     }

kernel/src/syscall/poll.rs

@@ -158,7 +158,7 @@ impl From<c_pollfd> for PollFd {
 
 impl From<PollFd> for c_pollfd {
     fn from(raw: PollFd) -> Self {
-        let fd = if let Some(fd) = raw.fd() { fd } else { -1 };
+        let fd = raw.fd().unwrap_or(-1);
         let events = raw.events().bits() as i16;
         let revents = raw.revents().get().bits() as i16;
         Self {

kernel/src/taskless.rs

@@ -61,6 +61,7 @@ pub struct Taskless {
     /// The function that will be called when executing this taskless job.
     callback: Box<RefCell<dyn FnMut() + Send + Sync + 'static>>,
     /// Whether this `Taskless` is disabled.
+    #[allow(unused)]
     is_disabled: AtomicBool,
     link: LinkedListAtomicLink,
 }
@@ -74,6 +75,7 @@ cpu_local! {
 
 impl Taskless {
     /// Creates a new `Taskless` instance with its callback function.
+    #[allow(unused)]
     pub fn new<F>(callback: F) -> Arc<Self>
     where
         F: FnMut() + Send + Sync + 'static,
@@ -94,6 +96,7 @@ impl Taskless {
     /// Schedules this taskless job and it will be executed in later time.
     ///
     /// If the taskless job has been scheduled, this function will do nothing.
+    #[allow(unused)]
     pub fn schedule(self: &Arc<Self>) {
         do_schedule(self, &TASKLESS_LIST);
         SoftIrqLine::get(TASKLESS_SOFTIRQ_ID).raise();
@@ -103,6 +106,7 @@ impl Taskless {
     /// in softirq context.
     ///
     /// If the taskless job has been scheduled, this function will do nothing.
+    #[allow(unused)]
     pub fn schedule_urgent(self: &Arc<Self>) {
         do_schedule(self, &TASKLESS_URGENT_LIST);
         SoftIrqLine::get(TASKLESS_URGENT_SOFTIRQ_ID).raise();
@@ -111,17 +115,20 @@ impl Taskless {
     /// Enables this `Taskless` so that it can be executed once it has been scheduled.
     ///
     /// A new `Taskless` is enabled by default.
+    #[allow(unused)]
     pub fn enable(&self) {
         self.is_disabled.store(false, Ordering::Release);
     }
 
     /// Disables this `Taskless` so that it can not be scheduled. Note that if the `Taskless`
     /// has been scheduled, it can still continue to complete this job.
+    #[allow(unused)]
     pub fn disable(&self) {
         self.is_disabled.store(true, Ordering::Release);
     }
 }
 
+#[allow(unused)]
 fn do_schedule(
     taskless: &Arc<Taskless>,
     taskless_list: &'static CpuLocal<RefCell<LinkedList<TasklessAdapter>>>,

kernel/src/thread/work_queue/mod.rs

@@ -2,6 +2,68 @@
 
 #![allow(dead_code)]
 
+//! Work queue mechanism.
+//!
+//! # Overview
+//!
+//! A `workqueue` is a kernel-level mechanism used to schedule and execute deferred work.
+//! Deferred work refers to tasks that need to be executed at some point in the future,
+//! but not necessarily immediately.
+//!
+//! The workqueue mechanism is implemented using a combination of kernel threads and data
+//! structures such as `WorkItem`, `WorkQueue`, `Worker` and `WorkerPool`. The `WorkItem`
+//! represents a task to be processed, while the `WorkQueue` maintains the queue of submitted
+//! `WorkItems`. The `Worker` is responsible for processing these submitted tasks,
+//! and the `WorkerPool` manages and schedules these workers.
+//!
+//! # Examples
+//!
+//! The system has a default work queue and worker pool,
+//! and it also provides high-level APIs for users to use.
+//! Here is a basic example to how to use those APIs.
+//!
+//! ```rust
+//! use crate::thread::work_queue::{submit_work_func, submit_work_item, WorkItem};
+//!
+//! // Submit to high priority queue.
+//! submit_work_func(||{ }, true);
+//!
+//! // Submit to low priority queue.
+//! submit_work_func(||{ }, false);
+//!
+//! fn deferred_task(){
+//!     // ...
+//! }
+//!
+//! // Create a work item.
+//! let work_item = Arc::new(WorkItem::new(Box::new(deferred_task)));
+//!
+//! // Submit to high priority queue.
+//! submit_work_item(work_item, true);
+//!
+//! // Submit to low priority queue.
+//! submit_work_item(work_item, false);
+//! ```
+//!
+//! Certainly, users can also create a dedicated WorkQueue and WorkerPool.
+//!
+//! ```rust
+//! use ostd::cpu::CpuSet;
+//! use crate::thread::work_queue::{WorkQueue, WorkerPool, WorkItem};
+//!
+//! fn deferred_task(){
+//!     // ...
+//! }
+//!
+//! let cpu_set = CpuSet::new_full();
+//! let high_pri_pool = WorkerPool::new(true, cpu_set);
+//! let my_queue = WorkQueue::new(Arc::downgrade(high_pri_pool.get().unwrap()));
+//!
+//! let work_item = Arc::new(WorkItem::new(Box::new(deferred_task)));
+//! my_queue.enqueue(work_item);
+//!
+//! ```
+
 use ostd::cpu::CpuSet;
 use spin::Once;
 use work_item::WorkItem;
@@ -19,68 +81,6 @@ static WORKERPOOL_HIGH_PRI: Once<Arc<WorkerPool>> = Once::new();
 static WORKQUEUE_GLOBAL_NORMAL: Once<Arc<WorkQueue>> = Once::new();
 static WORKQUEUE_GLOBAL_HIGH_PRI: Once<Arc<WorkQueue>> = Once::new();
 
-/// Work queue mechanism.
-///
-/// # Overview
-///
-/// A `workqueue` is a kernel-level mechanism used to schedule and execute deferred work.
-/// Deferred work refers to tasks that need to be executed at some point in the future,
-/// but not necessarily immediately.
-///
-/// The workqueue mechanism is implemented using a combination of kernel threads and data
-/// structures such as `WorkItem`, `WorkQueue`, `Worker` and `WorkerPool`. The `WorkItem`
-/// represents a task to be processed, while the `WorkQueue` maintains the queue of submitted
-/// `WorkItems`. The `Worker` is responsible for processing these submitted tasks,
-/// and the `WorkerPool` manages and schedules these workers.
-///
-/// # Examples
-///
-/// The system has a default work queue and worker pool,
-/// and it also provides high-level APIs for users to use.
-/// Here is a basic example to how to use those APIs.
-///
-/// ```rust
-/// use crate::thread::work_queue::{submit_work_func, submit_work_item, WorkItem};
-///
-/// // Submit to high priority queue.
-/// submit_work_func(||{ }, true);
-///
-/// // Submit to low priority queue.
-/// submit_work_func(||{ }, false);
-///
-/// fn deferred_task(){
-///     // ...
-/// }
-///
-/// // Create a work item.
-/// let work_item = Arc::new(WorkItem::new(Box::new(deferred_task)));
-///
-/// // Submit to high priority queue.
-/// submit_work_item(work_item, true);
-///
-/// // Submit to low priority queue.
-/// submit_work_item(work_item, false);
-/// ```
-///
-/// Certainly, users can also create a dedicated WorkQueue and WorkerPool.
-///
-/// ```rust
-/// use ostd::cpu::CpuSet;
-/// use crate::thread::work_queue::{WorkQueue, WorkerPool, WorkItem};
-///
-/// fn deferred_task(){
-///     // ...
-/// }
-///
-/// let cpu_set = CpuSet::new_full();
-/// let high_pri_pool = WorkerPool::new(true, cpu_set);
-/// let my_queue = WorkQueue::new(Arc::downgrade(high_pri_pool.get().unwrap()));
-///
-/// let work_item = Arc::new(WorkItem::new(Box::new(deferred_task)));
-/// my_queue.enqueue(work_item);
-///
-/// ```
-
 /// Submit a function to a global work queue.
 pub fn submit_work_func<F>(work_func: F, work_priority: WorkPriority)
 where

kernel/src/thread/work_queue/worker_pool.rs

@@ -57,6 +57,7 @@ pub trait WorkerScheduler: Sync + Send {
 }
 
 /// The `Monitor` is responsible for monitoring the `WorkerPool` for scheduling needs.
+///
 /// Currently, it only performs a liveness check, and attempts to schedule when no workers
 /// are found processing in the pool.
 pub struct Monitor {

kernel/src/time/clocks/cpu_clock.rs

@@ -13,6 +13,7 @@ pub struct CpuClock {
 }
 
 /// A profiling clock that contains a user CPU clock and a kernel CPU clock.
+///
 /// These two clocks record the CPU time in user mode and kernel mode respectively.
 /// Reading this clock directly returns the sum of both times.
 pub struct ProfClock {

kernel/src/util/iovec.rs

@@ -173,7 +173,7 @@ pub trait MultiWrite {
     }
 }
 
-impl<'a> MultiRead for VmReaderArray<'a> {
+impl MultiRead for VmReaderArray<'_> {
     fn read(&mut self, writer: &mut VmWriter<'_, Infallible>) -> Result<usize> {
         let mut total_len = 0;
 
@@ -192,7 +192,7 @@ impl<'a> MultiRead for VmReaderArray<'a> {
     }
 }
 
-impl<'a> MultiRead for VmReader<'a> {
+impl MultiRead for VmReader<'_> {
     fn read(&mut self, writer: &mut VmWriter<'_, Infallible>) -> Result<usize> {
         Ok(self.read_fallible(writer)?)
     }
@@ -202,7 +202,7 @@ impl<'a> MultiRead for VmReader<'a> {
     }
 }
 
-impl<'a> MultiWrite for VmWriterArray<'a> {
+impl MultiWrite for VmWriterArray<'_> {
     fn write(&mut self, reader: &mut VmReader<'_, Infallible>) -> Result<usize> {
         let mut total_len = 0;
 
@@ -221,7 +221,7 @@ impl<'a> MultiWrite for VmWriterArray<'a> {
     }
 }
 
-impl<'a> MultiWrite for VmWriter<'a> {
+impl MultiWrite for VmWriter<'_> {
     fn write(&mut self, reader: &mut VmReader<'_, Infallible>) -> Result<usize> {
         Ok(self.write_fallible(reader)?)
     }

kernel/src/util/net/addr/unix.rs

@@ -47,7 +47,9 @@ where
 
     bytes[..2].copy_from_slice(&(CSocketAddrFamily::AF_UNIX as u16).to_ne_bytes());
     #[allow(clippy::assertions_on_constants)]
-    const { assert!(CSocketAddrUnix::PATH_OFFSET == 2) };
+    const {
+        assert!(CSocketAddrUnix::PATH_OFFSET == 2)
+    };
 
     let sun_path = &mut bytes[CSocketAddrUnix::PATH_OFFSET..];
 

kernel/src/util/ring_buffer.rs

@@ -224,6 +224,7 @@ impl RingBuffer<u8> {
     /// Writes data from the `reader` to the `RingBuffer`.
     ///
     /// Returns the number of bytes written.
+    #[allow(unused)]
     pub fn write_fallible(&mut self, reader: &mut dyn MultiRead) -> Result<usize> {
         let mut producer = Producer {
             rb: self,

osdk/test-kernel/Cargo.toml

@@ -11,4 +11,4 @@ repository ="https://github.com/asterinas/asterinas"
 [dependencies]
 ostd = { version = "0.9.2", path = "../../ostd" }
 owo-colors = "4.0.0"
-unwinding = { version = "0.2.2", default-features = false, features = ["fde-gnu-eh-frame-hdr", "hide-trace", "panic", "personality", "unwinder"] }
+unwinding = { version = "0.2.3", default-features = false, features = ["fde-gnu-eh-frame-hdr", "hide-trace", "panic", "personality", "unwinder"] }

osdk/test-kernel/src/path.rs

@@ -46,6 +46,7 @@ impl KtestPath {
         self.path.pop_back()
     }
 
+    #[allow(dead_code)]
     pub fn push_front(&mut self, s: &str) {
         self.path.push_front(PathElement::from(s))
     }
@@ -54,6 +55,7 @@ impl KtestPath {
         self.path.pop_front()
     }
 
+    #[allow(dead_code)]
     pub fn len(&self) -> usize {
         self.path.len()
     }

osdk/test-kernel/src/tree.rs

@@ -28,6 +28,7 @@ pub struct KtestModule {
 }
 
 impl KtestModule {
+    #[allow(dead_code)]
     pub fn nr_this_tests(&self) -> usize {
         self.tests.len()
     }

ostd/Cargo.toml

@@ -39,7 +39,7 @@ owo-colors = { version = "3", optional = true }
 ostd-pod = { git = "https://github.com/asterinas/ostd-pod", rev = "c4644be", version = "0.1.1" }
 spin = "0.9.4"
 static_assertions = "1.1.0"
-unwinding = { version = "0.2.2", default-features = false, features = ["fde-gnu-eh-frame-hdr", "hide-trace", "panic", "personality", "unwinder"] }
+unwinding = { version = "0.2.3", default-features = false, features = ["fde-gnu-eh-frame-hdr", "hide-trace", "panic", "personality", "unwinder"] }
 volatile = { version = "0.4.5", features = ["unstable"] }
 xarray = { git = "https://github.com/asterinas/xarray", version = "0.1.0" }
 

ostd/libs/align_ext/src/lib.rs

@@ -6,9 +6,6 @@
 /// `u64`, and `usize`, to provide methods to make integers aligned to a
 /// power of two.
 pub trait AlignExt {
-    /// Returns whether the number is a power of two
-    fn is_power_of_two(&self) -> bool;
-
     /// Returns to the smallest number that is greater than or equal to
     /// `self` and is a multiple of the given power of two.
     ///
@@ -50,11 +47,6 @@ macro_rules! impl_align_ext {
     ($( $uint_type:ty ),+,) => {
         $(
             impl AlignExt for $uint_type {
-                #[inline]
-                fn is_power_of_two(&self) -> bool {
-                    (*self != 0) && ((*self & (*self - 1)) == 0)
-                }
-
                 #[inline]
                 fn align_up(self, align: Self) -> Self {
                     assert!(align.is_power_of_two() && align >= 2);

ostd/libs/linux-bzimage/setup/src/console.rs

@@ -33,20 +33,37 @@ impl Write for Stdout {
     }
 }
 
+/// Print a string to the console.
+///
 /// This is used when dyn Trait is not supported or fmt::Arguments is fragile to use in PIE.
 ///
-/// SAFETY: init() must be called before print_str() and there should be no race conditions.
+/// # Safety
+///
+/// [`init()`] must be called before it and there should be no race conditions.
 pub unsafe fn print_str(s: &str) {
+    #[allow(static_mut_refs)]
     STDOUT.write_str(s).unwrap();
 }
 
+/// Print a single character to the console.
+///
+/// This is used when dyn Trait is not supported or fmt::Arguments is fragile to use in PIE.
+///
+/// # Safety
+///
+/// [`init()`] must be called before it and there should be no race conditions.
 unsafe fn print_char(c: char) {
+    #[allow(static_mut_refs)]
     STDOUT.serial_port.send(c as u8);
 }
 
+/// Print a hexadecimal number to the console.
+///
 /// This is used when dyn Trait is not supported or fmt::Arguments is fragile to use in PIE.
 ///
-/// SAFETY: init() must be called before print_hex() and there should be no race conditions.
+/// # Safety
+///
+/// [`init()`] must be called before it and there should be no race conditions.
 pub unsafe fn print_hex(n: u64) {
     print_str("0x");
     for i in (0..16).rev() {

ostd/libs/ostd-test/src/lib.rs

@@ -65,7 +65,6 @@
 //!
 
 #![cfg_attr(not(test), no_std)]
-#![feature(panic_info_message)]
 
 extern crate alloc;
 use alloc::{boxed::Box, string::String};

ostd/src/arch/x86/iommu/registers/mod.rs

@@ -30,6 +30,7 @@ use crate::{
 };
 
 #[derive(Debug, Clone, Copy)]
+#[allow(dead_code)]
 pub struct IommuVersion {
     major: u8,
     minor: u8,
@@ -37,11 +38,13 @@ pub struct IommuVersion {
 
 impl IommuVersion {
     /// Major version number
+    #[allow(dead_code)]
     pub fn major(&self) -> u8 {
         self.major
     }
 
     /// Minor version number
+    #[allow(dead_code)]
     pub fn minor(&self) -> u8 {
         self.minor
     }
@@ -50,6 +53,7 @@ impl IommuVersion {
 /// Important registers used by IOMMU.
 #[derive(Debug)]
 pub struct IommuRegisters {
+    #[allow(dead_code)]
     version: Volatile<&'static u32, ReadOnly>,
     capability: Volatile<&'static u64, ReadOnly>,
     extended_capability: Volatile<&'static u64, ReadOnly>,
@@ -62,6 +66,7 @@ pub struct IommuRegisters {
 
 impl IommuRegisters {
     /// Version of IOMMU
+    #[allow(dead_code)]
     pub fn version(&self) -> IommuVersion {
         let version = self.version.read();
         IommuVersion {

ostd/src/arch/x86/kernel/apic/mod.rs

@@ -195,6 +195,7 @@ impl ApicId {
     /// In x2APIC mode, the 32-bit logical x2APIC ID, which can be read from
     /// LDR, is derived from the 32-bit local x2APIC ID:
     /// Logical x2APIC ID = [(x2APIC ID[19:4] << 16) | (1 << x2APIC ID[3:0])]
+    #[allow(unused)]
     pub fn x2apic_logical_id(&self) -> u32 {
         self.x2apic_logical_cluster_id() << 16 | 1 << self.x2apic_logical_field_id()
     }

ostd/src/arch/x86/qemu.rs

@@ -2,11 +2,13 @@
 
 //! Provides the ability to exit QEMU and return a value as debug result.
 
-/// The exit code of x86 QEMU isa debug device. In `qemu-system-x86_64` the
-/// exit code will be `(code << 1) | 1`. So you could never let QEMU invoke
-/// `exit(0)`. We also need to check if the exit code is returned by the
-/// kernel, so we couldn't use 0 as exit_success because this may conflict
-/// with QEMU return value 1, which indicates that QEMU itself fails.
+/// The exit code of x86 QEMU isa debug device.
+///
+/// In `qemu-system-x86_64` the exit code will be `(code << 1) | 1`. So you
+/// could never let QEMU invoke `exit(0)`. We also need to check if the exit
+/// code is returned by the kernel, so we couldn't use 0 as exit_success
+/// because this may conflict with QEMU return value 1, which indicates that
+/// QEMU itself fails.
 #[derive(Debug, Clone, Copy, PartialEq, Eq)]
 #[repr(u32)]
 pub enum QemuExitCode {

ostd/src/arch/x86/timer/mod.rs

@@ -17,15 +17,18 @@ use crate::{
     trap::{self, IrqLine, TrapFrame},
 };
 
-/// The timer frequency (Hz). Here we choose 1000Hz since 1000Hz is easier for unit conversion and
-/// convenient for timer. What's more, the frequency cannot be set too high or too low, 1000Hz is
-/// a modest choice.
+/// The timer frequency (Hz).
 ///
-/// For system performance reasons, this rate cannot be set too high, otherwise most of the time
-/// is spent executing timer code.
+/// Here we choose 1000Hz since 1000Hz is easier for unit conversion and
+/// convenient for timer. What's more, the frequency cannot be set too high or
+/// too low, 1000Hz is a modest choice.
 ///
-/// Due to hardware limitations, this value cannot be set too low; for example, PIT cannot accept
-/// frequencies lower than 19Hz = 1193182 / 65536 (Timer rate / Divider)
+/// For system performance reasons, this rate cannot be set too high, otherwise
+/// most of the time is spent executing timer code.
+///
+/// Due to hardware limitations, this value cannot be set too low; for example,
+/// PIT cannot accept frequencies lower than 19Hz = 1193182 / 65536 (Timer rate
+/// / Divider)
 pub const TIMER_FREQ: u64 = 1000;
 
 static TIMER_IRQ: Once<IrqLine> = Once::new();

ostd/src/cpu/local/cell.rs

@@ -208,6 +208,7 @@ impl<T: 'static + SingleInstructionBitXorAssign<T>> CpuLocalCell<T> {
     ///
     /// Note that this memory operation will not be elided or reordered by the
     /// compiler since it is a black-box.
+    #[allow(unused)]
     pub fn bitxor_assign(&'static self, rhs: T) {
         let offset = self as *const _ as usize - __cpu_local_start as usize;
         // SAFETY: The CPU-local object is defined in the `.cpu_local` section,

ostd/src/cpu/local/single_instr.rs

@@ -114,6 +114,7 @@ pub trait SingleInstructionBitXorAssign<Rhs = Self> {
     /// # Safety
     ///
     /// Please refer to the module-level documentation of [`self`].
+    #[allow(unused)]
     unsafe fn bitxor_assign(offset: *mut Self, rhs: Rhs);
 }
 

ostd/src/lib.rs

@@ -2,24 +2,20 @@
 
 //! The standard library for Asterinas and other Rust OSes.
 #![feature(alloc_error_handler)]
-#![feature(const_mut_refs)]
+#![feature(allocator_api)]
 #![feature(const_ptr_sub_ptr)]
 #![feature(const_trait_impl)]
 #![feature(core_intrinsics)]
 #![feature(coroutines)]
 #![feature(fn_traits)]
 #![feature(generic_const_exprs)]
-#![feature(is_none_or)]
 #![feature(iter_from_coroutine)]
 #![feature(let_chains)]
 #![feature(min_specialization)]
 #![feature(negative_impls)]
-#![feature(new_uninit)]
-#![feature(panic_info_message)]
 #![feature(ptr_sub_ptr)]
 #![feature(strict_provenance)]
 #![feature(sync_unsafe_cell)]
-#![feature(allocator_api)]
 // The `generic_const_exprs` feature is incomplete however required for the page table
 // const generic implementation. We are using this feature in a conservative manner.
 #![allow(incomplete_features)]
@@ -81,7 +77,8 @@ pub unsafe fn init() {
     // SAFETY: This function is called only once and only on the BSP.
     unsafe { cpu::local::early_init_bsp_local_base() };
 
-    mm::heap_allocator::init();
+    // SAFETY: This function is called only once and only on the BSP.
+    unsafe { mm::heap_allocator::init() };
 
     boot::init();
     logger::init();

ostd/src/mm/frame/mod.rs

@@ -199,7 +199,7 @@ pub struct FrameRef<'a> {
     _marker: PhantomData<&'a Frame>,
 }
 
-impl<'a> Deref for FrameRef<'a> {
+impl Deref for FrameRef<'_> {
     type Target = Frame;
 
     fn deref(&self) -> &Self::Target {
@@ -210,7 +210,10 @@ impl<'a> Deref for FrameRef<'a> {
 // SAFETY: `Frame` is essentially an `*const MetaSlot` that could be used as a `*const` pointer.
 // The pointer is also aligned to 4.
 unsafe impl xarray::ItemEntry for Frame {
-    type Ref<'a> = FrameRef<'a> where Self: 'a;
+    type Ref<'a>
+        = FrameRef<'a>
+    where
+        Self: 'a;
 
     fn into_raw(self) -> *const () {
         let ptr = self.page.ptr;

ostd/src/mm/heap_allocator/mod.rs

@@ -31,11 +31,16 @@ const INIT_KERNEL_HEAP_SIZE: usize = PAGE_SIZE * 256;
 #[repr(align(4096))]
 struct InitHeapSpace([u8; INIT_KERNEL_HEAP_SIZE]);
 
-static mut HEAP_SPACE: InitHeapSpace = InitHeapSpace([0; INIT_KERNEL_HEAP_SIZE]);
-
-pub fn init() {
+/// Initialize the heap allocator.
+///
+/// # Safety
+///
+/// This function should be called only once.
+pub unsafe fn init() {
+    static mut HEAP_SPACE: InitHeapSpace = InitHeapSpace([0; INIT_KERNEL_HEAP_SIZE]);
     // SAFETY: The HEAP_SPACE is a static memory range, so it's always valid.
     unsafe {
+        #[allow(static_mut_refs)]
         HEAP_ALLOCATOR.init(HEAP_SPACE.0.as_ptr(), INIT_KERNEL_HEAP_SIZE);
     }
 }

ostd/src/mm/heap_allocator/slab_allocator/mod.rs

@@ -222,6 +222,7 @@ impl Heap {
 
     /// Returns bounds on the guaranteed usable size of a successful
     /// allocation created with the specified `layout`.
+    #[allow(unused)]
     pub fn usable_size(&self, layout: Layout) -> (usize, usize) {
         match Heap::layout_to_allocator(&layout) {
             HeapAllocator::Slab64Bytes => (layout.size(), 64),
@@ -257,6 +258,7 @@ impl Heap {
     }
 
     /// Returns total memory size in bytes of the heap.
+    #[allow(unused)]
     pub fn total_bytes(&self) -> usize {
         self.slab_64_bytes.total_blocks() * 64
             + self.slab_128_bytes.total_blocks() * 128
@@ -269,6 +271,7 @@ impl Heap {
     }
 
     /// Returns allocated memory size in bytes.
+    #[allow(unused)]
     pub fn used_bytes(&self) -> usize {
         self.slab_64_bytes.used_blocks() * 64
             + self.slab_128_bytes.used_blocks() * 128
@@ -281,6 +284,7 @@ impl Heap {
     }
 
     /// Returns available memory size in bytes.
+    #[allow(unused)]
     pub fn available_bytes(&self) -> usize {
         self.total_bytes() - self.used_bytes()
     }

ostd/src/mm/heap_allocator/slab_allocator/slab.rs

@@ -45,10 +45,12 @@ impl<const BLK_SIZE: usize> Slab<BLK_SIZE> {
         }
     }
 
+    #[allow(unused)]
     pub fn total_blocks(&self) -> usize {
         self.total_blocks
     }
 
+    #[allow(unused)]
     pub fn used_blocks(&self) -> usize {
         self.total_blocks - self.free_block_list.len()
     }
@@ -120,6 +122,7 @@ impl<const BLK_SIZE: usize> FreeBlockList<BLK_SIZE> {
     }
 
     fn pop(&mut self) -> Option<&'static mut FreeBlock> {
+        #[allow(clippy::manual_inspect)]
         self.head.take().map(|node| {
             self.head = node.next.take();
             self.len -= 1;

ostd/src/mm/io.rs

@@ -543,7 +543,7 @@ impl<'a> VmReader<'a, Infallible> {
     }
 }
 
-impl<'a> VmReader<'a, Fallible> {
+impl VmReader<'_, Fallible> {
     /// Constructs a `VmReader` from a pointer and a length, which represents
     /// a memory range in user space.
     ///
@@ -608,7 +608,7 @@ impl<'a> VmReader<'a, Fallible> {
     }
 }
 
-impl<'a, Fallibility> VmReader<'a, Fallibility> {
+impl<Fallibility> VmReader<'_, Fallibility> {
     /// Returns the number of bytes for the remaining data.
     pub const fn remain(&self) -> usize {
         // SAFETY: the end is equal to or greater than the cursor.
@@ -794,7 +794,7 @@ impl<'a> VmWriter<'a, Infallible> {
     }
 }
 
-impl<'a> VmWriter<'a, Fallible> {
+impl VmWriter<'_, Fallible> {
     /// Constructs a `VmWriter` from a pointer and a length, which represents
     /// a memory range in user space.
     ///
@@ -870,7 +870,7 @@ impl<'a> VmWriter<'a, Fallible> {
     }
 }
 
-impl<'a, Fallibility> VmWriter<'a, Fallibility> {
+impl<Fallibility> VmWriter<'_, Fallibility> {
     /// Returns the number of bytes for the available space.
     pub const fn avail(&self) -> usize {
         // SAFETY: the end is equal to or greater than the cursor.

ostd/src/mm/page_table/cursor.rs

@@ -334,8 +334,8 @@ where
     }
 }
 
-impl<'a, M: PageTableMode, E: PageTableEntryTrait, C: PagingConstsTrait> Iterator
-    for Cursor<'a, M, E, C>
+impl<M: PageTableMode, E: PageTableEntryTrait, C: PagingConstsTrait> Iterator
+    for Cursor<'_, M, E, C>
 where
     [(); C::NR_LEVELS as usize]:,
 {

ostd/src/mm/page_table/test.rs

@@ -147,17 +147,6 @@ fn test_user_copy_on_write() {
     assert!(child_pt.query(from.start + 10).is_none());
 }
 
-#[derive(Clone, Debug, Default)]
-struct BasePagingConsts {}
-
-impl PagingConstsTrait for BasePagingConsts {
-    const NR_LEVELS: PagingLevel = 4;
-    const BASE_PAGE_SIZE: usize = PAGE_SIZE;
-    const ADDRESS_WIDTH: usize = 48;
-    const HIGHEST_TRANSLATION_LEVEL: PagingLevel = 1;
-    const PTE_SIZE: usize = core::mem::size_of::<PageTableEntry>();
-}
-
 impl<M: PageTableMode, E: PageTableEntryTrait, C: PagingConstsTrait> PageTable<M, E, C>
 where
     [(); C::NR_LEVELS as usize]:,

ostd/src/panicking.rs

@@ -22,6 +22,8 @@ cpu_local_cell! {
     static IN_PANIC: bool = false;
 }
 
+/// The asterinas panic handler.
+///
 /// The panic handler must be defined in the binary crate or in the crate that the binary
 /// crate explicitly declares by `extern crate`. We cannot let the base crate depend on OSTD
 /// due to prismatic dependencies. That's why we export this symbol and state the

ostd/src/sync/atomic_bits.rs

@@ -116,7 +116,7 @@ impl<'a> Iter<'a> {
     }
 }
 
-impl<'a> Iterator for Iter<'a> {
+impl Iterator for Iter<'_> {
     type Item = bool;
 
     fn next(&mut self) -> Option<bool> {
@@ -171,7 +171,7 @@ impl<'a> OnesIter<'a> {
     }
 }
 
-impl<'a> Iterator for OnesIter<'a> {
+impl Iterator for OnesIter<'_> {
     type Item = usize;
 
     fn next(&mut self) -> Option<usize> {
@@ -236,7 +236,7 @@ impl<'a> ZeroesIter<'a> {
     }
 }
 
-impl<'a> Iterator for ZeroesIter<'a> {
+impl Iterator for ZeroesIter<'_> {
     type Item = usize;
 
     fn next(&mut self) -> Option<usize> {

ostd/src/task/kernel_stack.rs

@@ -26,13 +26,6 @@ pub struct KernelStack {
 }
 
 impl KernelStack {
-    pub fn new() -> Result<Self> {
-        Ok(Self {
-            segment: FrameAllocOptions::new(STACK_SIZE_IN_PAGES as usize).alloc_contiguous()?,
-            has_guard_page: false,
-        })
-    }
-
     /// Generates a kernel stack with a guard page.
     /// An additional page is allocated and be regarded as a guard page, which should not be accessed.  
     pub fn new_with_guard_page() -> Result<Self> {

ostd/src/user.rs

@@ -118,7 +118,7 @@ pub struct UserMode<'a> {
 }
 
 // An instance of `UserMode` is bound to the current task. So it must not be sent to other tasks.
-impl<'a> !Send for UserMode<'a> {}
+impl !Send for UserMode<'_> {}
 // Note that implementing `!Sync` is unnecessary
 // because entering the user space via `UserMode` requires taking a mutable reference.