Add CR3 to Context (x86_64)

crate/memory/src/memory_set.rs

@@ -11,6 +11,7 @@ pub trait InactivePageTable {
     fn edit(&mut self, f: impl FnOnce(&mut Self::Active));
     unsafe fn activate(&self);
     unsafe fn with(&self, f: impl FnOnce());
+    fn token(&self) -> usize;
 
     fn alloc_frame() -> Option<PhysAddr>;
     fn dealloc_frame(target: PhysAddr);
@@ -171,22 +172,12 @@ impl<T: InactivePageTable> MemorySet<T> {
     pub unsafe fn activate(&self) {
         self.page_table.activate();
     }
+    pub fn token(&self) -> usize {
+        self.page_table.token()
+    }
     pub fn kstack_top(&self) -> usize {
         self.kstack.top
     }
-    pub fn clone(&self) -> Self {
-        let mut page_table = T::new();
-        page_table.edit(|pt| {
-            for area in self.areas.iter() {
-                area.map::<T>(pt);
-            }
-        });
-        MemorySet {
-            areas: self.areas.clone(),
-            page_table,
-            kstack: T::alloc_stack(),
-        }
-    }
     pub fn clear(&mut self) {
         let Self { ref mut page_table, ref mut areas, .. } = self;
         page_table.edit(|pt| {
@@ -198,9 +189,19 @@ impl<T: InactivePageTable> MemorySet<T> {
     }
 }
 
-impl<T: InactivePageTable> Drop for MemorySet<T> {
+impl<T: InactivePageTable> Clone for MemorySet<T> {
-    fn drop(&mut self) {
+    fn clone(&self) -> Self {
-        self.clear();
+        let mut page_table = T::new();
+        page_table.edit(|pt| {
+            for area in self.areas.iter() {
+                area.map::<T>(pt);
+            }
+        });
+        MemorySet {
+            areas: self.areas.clone(),
+            page_table,
+            kstack: T::alloc_stack(),
+        }
     }
 }
 

src/arch/x86_64/interrupt/trapframe.rs

@@ -64,6 +64,7 @@ impl TrapFrame {
 #[derive(Debug, Default)]
 #[repr(C)]
 struct ContextData {
+    cr3: usize,
     r15: usize,
     r14: usize,
     r13: usize,
@@ -74,49 +75,22 @@ struct ContextData {
 }
 
 impl ContextData {
-    fn new() -> Self {
+    fn new(cr3: usize) -> Self {
-        let mut context = ContextData::default();
+        ContextData { rip: forkret as usize, cr3, ..ContextData::default() }
-        context.rip = forkret as usize;
-        context
     }
 }
 
 /// 新线程的内核栈初始内容
 #[derive(Debug)]
 #[repr(C)]
-pub struct InitStack {
+struct InitStack {
     context: ContextData,
     trapret: usize,
     tf: TrapFrame,
 }
 
 impl InitStack {
-    pub fn new_kernel_thread(entry: extern fn(usize) -> !, arg: usize, rsp: usize) -> Self {
+    unsafe fn push_at(self, stack_top: usize) -> Context {
-        InitStack {
-            context: ContextData::new(),
-            trapret: trap_ret as usize,
-            tf: TrapFrame::new_kernel_thread(entry, arg, rsp),
-        }
-    }
-    pub fn new_user_thread(entry_addr: usize, rsp: usize, is32: bool) -> Self {
-        InitStack {
-            context: ContextData::new(),
-            trapret: trap_ret as usize,
-            tf: TrapFrame::new_user_thread(entry_addr, rsp, is32),
-        }
-    }
-    pub fn new_fork(tf: &TrapFrame) -> Self {
-        InitStack {
-            context: ContextData::new(),
-            trapret: trap_ret as usize,
-            tf: {
-                let mut tf = tf.clone();
-                tf.rax = 0;
-                tf
-            },
-        }
-    }
-    pub unsafe fn push_at(self, stack_top: usize) -> Context {
         let ptr = (stack_top as *mut Self).offset(-1);
         *ptr = self;
         Context(ptr as usize)
@@ -158,6 +132,8 @@ impl Context {
         push r13
         push r14
         push r15
+        mov r15, cr3
+        push r15
 
         // Switch stacks
         mov [rdi], rsp      // rdi = from_rsp
@@ -165,6 +141,8 @@ impl Context {
 
         // Save old callee-save registers
         pop r15
+        mov cr3, r15
+        pop r15
         pop r14
         pop r13
         pop r12
@@ -179,4 +157,30 @@ impl Context {
     pub unsafe fn null() -> Self {
         Context(0)
     }
+
+    pub unsafe fn new_kernel_thread(entry: extern fn(usize) -> !, arg: usize, kstack_top: usize, cr3: usize) -> Self {
+        InitStack {
+            context: ContextData::new(cr3),
+            trapret: trap_ret as usize,
+            tf: TrapFrame::new_kernel_thread(entry, arg, kstack_top),
+        }.push_at(kstack_top)
+    }
+    pub unsafe fn new_user_thread(entry_addr: usize, ustack_top: usize, kstack_top: usize, is32: bool, cr3: usize) -> Self {
+        InitStack {
+            context: ContextData::new(cr3),
+            trapret: trap_ret as usize,
+            tf: TrapFrame::new_user_thread(entry_addr, ustack_top, is32),
+        }.push_at(kstack_top)
+    }
+    pub unsafe fn new_fork(tf: &TrapFrame, kstack_top: usize, cr3: usize) -> Self {
+        InitStack {
+            context: ContextData::new(cr3),
+            trapret: trap_ret as usize,
+            tf: {
+                let mut tf = tf.clone();
+                tf.rax = 0;
+                tf
+            },
+        }.push_at(kstack_top)
+    }
 }

src/arch/x86_64/paging.rs

@@ -213,6 +213,10 @@ impl InactivePageTable for InactivePageTable0 {
         }
     }
 
+    fn token(&self) -> usize {
+        self.p4_frame.start_address().as_u64() as usize // as CR3
+    }
+
     fn alloc_frame() -> Option<usize> {
         alloc_frame()
     }

src/memory.rs

@@ -25,8 +25,8 @@ pub fn dealloc_frame(target: usize) {
 // alloc from heap
 pub fn alloc_stack() -> Stack {
     use alloc::boxed::Box;
-    const STACK_SIZE: usize = 8 * 4096;
+    const STACK_SIZE: usize = 0x8000;
-    #[repr(align(4096))]
+    #[repr(align(0x8000))]
     struct StackData([u8; STACK_SIZE]);
     let data = Box::new(StackData([0; STACK_SIZE]));
     let bottom = Box::into_raw(data) as usize;

src/process/process.rs

@@ -11,7 +11,6 @@ pub struct Process {
     pub(in process) memory_set: MemorySet,
     pub(in process) status: Status,
     pub(in process) context: Context,
-    pub(in process) is_user: bool,
 }
 
 pub type Pid = usize;
@@ -30,8 +29,7 @@ impl Process {
     /// Make a new kernel thread
     pub fn new(name: &str, entry: extern fn(usize) -> !, arg: usize) -> Self {
         let ms = MemorySet::new();
-        let data = InitStack::new_kernel_thread(entry, arg, ms.kstack_top());
+        let context = unsafe { Context::new_kernel_thread(entry, arg, ms.kstack_top(), ms.token()) };
-        let context = unsafe { data.push_at(ms.kstack_top()) };
 
         Process {
             pid: 0,
@@ -40,7 +38,6 @@ impl Process {
             memory_set: ms,
             status: Status::Ready,
             context,
-            is_user: false,
         }
     }
 
@@ -55,7 +52,6 @@ impl Process {
             memory_set: MemorySet::new(),
             status: Status::Running,
             context: unsafe { Context::null() }, // will be set at first schedule
-            is_user: false,
         }
     }
 
@@ -111,8 +107,10 @@ impl Process {
 
 
         // Allocate kernel stack and push trap frame
-        let data = InitStack::new_user_thread(entry_addr, user_stack_top - 8, is32);
+        let context = unsafe {
-        let context = unsafe { data.push_at(memory_set.kstack_top()) };
+            Context::new_user_thread(
+                entry_addr, user_stack_top - 8, memory_set.kstack_top(), is32, memory_set.token())
+        };
 
         Process {
             pid: 0,
@@ -121,14 +119,11 @@ impl Process {
             memory_set,
             status: Status::Ready,
             context,
-            is_user: true,
         }
     }
 
     /// Fork
     pub fn fork(&self, tf: &TrapFrame) -> Self {
-        assert!(self.is_user);
-
         // Clone memory set, make a new page table
         let memory_set = self.memory_set.clone();
 
@@ -147,9 +142,8 @@ impl Process {
             });
         }
 
-        // Allocate kernel stack and push trap frame
+        // Push context at kstack top
-        let data = InitStack::new_fork(tf);
+        let context = unsafe { Context::new_fork(tf, memory_set.kstack_top(), memory_set.token()) };
-        let context = unsafe { data.push_at(memory_set.kstack_top()) };
 
         Process {
             pid: 0,
@@ -158,7 +152,6 @@ impl Process {
             memory_set,
             status: Status::Ready,
             context,
-            is_user: true,
         }
     }
 

src/process/processor.rs

@@ -133,8 +133,6 @@ impl Processor {
 
         info!("switch from {} to {}\n  rsp: ??? -> {:?}", pid0, pid, to.context);
         unsafe {
-            // switch page table
-            to.memory_set.activate();
             // FIXME: safely pass MutexGuard
             use core::mem::forget;
             super::PROCESSOR.try().unwrap().force_unlock();

src/thread.rs

@@ -3,11 +3,13 @@
 //! Based on process mod.
 //! Used in the kernel.
 
-use process::*;
+use alloc::boxed::Box;
+use alloc::BTreeMap;
+use core::any::Any;
 use core::marker::PhantomData;
 use core::ptr;
 use core::time::Duration;
-use alloc::boxed::Box;
+use process::*;
 
 /// Gets a handle to the thread that invokes it.
 pub fn current() -> Thread {
@@ -37,8 +39,8 @@ pub fn spawn<F, T>(f: F) -> JoinHandle<T>
 {
     info!("spawn:");
     use process;
-    let f = Box::leak(Box::new(f));
+    let f = Box::into_raw(Box::new(f));
-    let pid = process::add_kernel_process(kernel_thread_entry::<F, T>, f as *mut _ as usize);
+    let pid = process::add_kernel_process(kernel_thread_entry::<F, T>, f as usize);
     return JoinHandle {
         thread: Thread { pid },
         mark: PhantomData,