new:在fork时拷贝signal和sighand (#91)

* refcount初始化

* new: 实现copy_sighand
del: 删除sighand_struct的wqh, 待将来有需要时，替换成rust版本的

* new: 拷贝signal
bugfix: 解决拷贝sighand时的uaf问题

kernel/src/libs/atomic.rs

@@ -1,11 +1,26 @@
-use core::ptr::read_volatile;
+#![allow(dead_code)]
+use core::ptr::{read_volatile, write_volatile};
 
 use crate::include::bindings::bindings::atomic_t;
 
 /// @brief 原子的读取指定的原子变量的值
 #[inline]
-pub fn atomic_read(ato:*const atomic_t)-> i64{
-    unsafe{
+pub fn atomic_read(ato: *const atomic_t) -> i64 {
+    unsafe {
         return read_volatile(&(*ato).value);
     }
-}
+}
+
+/// @brief 原子的设置原子变量的值
+#[inline]
+pub fn atomic_set(ato: *mut atomic_t, value:i64) {
+    unsafe{
+        write_volatile(&mut (*ato).value, value);
+    }
+}
+
+impl Default for atomic_t {
+    fn default() -> Self {
+        Self { value: 0 }
+    }
+}

kernel/src/libs/list.rs

@@ -0,0 +1,15 @@
+use crate::include::bindings::bindings::List;
+
+/// @brief 初始化链表
+#[inline]
+pub fn list_init(list: *mut List) {
+    unsafe{*list}.prev = list;
+    unsafe{*list}.next = list;
+}
+
+impl Default for List{
+    fn default() -> Self {
+       let x= Self { prev: 0 as *mut List, next: 0 as *mut List };
+       return x;
+    }
+}

kernel/src/libs/mod.rs

@@ -3,4 +3,6 @@ pub mod spinlock;
 pub mod ffi_convert;
 #[macro_use]
 pub mod refcount;
-pub mod atomic;
+pub mod atomic;
+pub mod wait_queue;
+pub mod list;

kernel/src/libs/refcount.rs

@@ -7,6 +7,12 @@ pub struct RefCount {
     pub refs: atomic_t,
 }
 
+impl Default for RefCount{
+    fn default() -> Self {
+        Self { refs:  atomic_t { value: 1 }}
+    }
+}
+
 /// @brief 将给定的来自bindgen的refcount_t解析为Rust的RefCount的引用
 impl FFIBind2Rust<crate::include::bindings::bindings::refcount_struct> for RefCount{
     fn convert_mut<'a>(
@@ -21,10 +27,11 @@ impl FFIBind2Rust<crate::include::bindings::bindings::refcount_struct> for RefCo
     }
 }
 
+/// @brief 以指定的值初始化refcount
 macro_rules! REFCOUNT_INIT {
     ($x:expr) => {
         $crate::libs::refcount::RefCount {
-            refs: atomic_t { value: 0 },
+            refs: $crate::include::bindings::bindings::atomic_t { value: $x },
         }
     };
 }

kernel/src/libs/spinlock.rs

@@ -28,3 +28,9 @@ pub fn spin_is_locked(lock: &spinlock_t) -> bool {
 
     return if val == 0 { true } else { false };
 }
+
+impl Default for spinlock_t {
+    fn default() -> Self {
+        Self { lock: 1 }
+    }
+}

kernel/src/libs/wait_queue.rs

@@ -0,0 +1,12 @@
+use crate::include::bindings::bindings::{wait_queue_head_t};
+
+use super::{list::list_init};
+
+
+impl Default for wait_queue_head_t{
+    fn default() -> Self {
+        let mut x = Self { wait_list: Default::default(), lock: Default::default() };
+        list_init(&mut x.wait_list);
+        return x;
+    }
+}