fix user stack

tornado-kernel/src/main.rs

@@ -36,7 +36,7 @@ pub extern "C" fn rust_main(hart_id: usize) -> ! {
         fn _swap_frame();
         fn _user_to_supervisor();
         fn _supervisor_to_user();
-        fn _user_stack_bottom();
+        fn _user_data();
     }
 
     unsafe { 
@@ -91,7 +91,7 @@ pub extern "C" fn rust_main(hart_id: usize) -> ! {
     println!("_swap_frame: {:#x}", _swap_frame as usize);
     println!("_user_to_supervisor: {:#x}", _user_to_supervisor as usize);
     println!("_supervisor_to_user: {:#x}", _supervisor_to_user as usize);
-    println!("_user_stack_bottom: {:#x}", _user_stack_bottom as usize);
+    println!("_user_data: {:#x}", _user_data as usize);
 
     // let executor = task::Executor::default();
 
@@ -111,10 +111,9 @@ pub extern "C" fn rust_main(hart_id: usize) -> ! {
     let kernel_memory = memory::MemorySet::new_kernel().expect("create kernel memory set");
     kernel_memory.activate();
     let process = task::Process::new(kernel_memory).expect("create process 1");
-    let _stack_handle = process.alloc_stack().expect("alloc initial stack");
+    let stack_handle = process.alloc_stack().expect("alloc initial stack");
     // 尝试进入用户态
-    user::try_enter_user()
-
+    user::try_enter_user(stack_handle.end.0 - 4)
     // let task_1 = task::KernelTask::new(task_1(), process.clone());
     // let task_2 = task::KernelTask::new(task_2(), process.clone());
     // let task_3 = task::KernelTask::new(FibonacciFuture::new(5), process);

tornado-kernel/src/memory/address.rs

@@ -58,6 +58,10 @@ impl PhysicalPageNumber {
     pub const fn ceil(address: PhysicalAddress) -> Self {
         Self(address.0 / PAGE_SIZE + (address.0 % PAGE_SIZE != 0) as usize)
     }
+    /// 从 satp 寄存器中取出根页表物理页号
+    pub fn from_satp(satp: usize) -> Self {
+        Self(satp.get_bits(0..44))
+    }
     /// 得到物理页的起始地址
     pub fn start_address(&self) -> PhysicalAddress {
         PhysicalAddress(self.0 << 12)

tornado-kernel/src/memory/mapping/mapping.rs

@@ -1,6 +1,7 @@
 use crate::memory::{AddressSpaceId, PhysicalPageNumber, PhysicalAddress, VirtualAddress, VirtualPageNumber, config::PAGE_SIZE, frame::FrameTracker, frame_alloc};
 use super::{Flags, MapType, Segment, page_table::{PageTable, PageTableTracker}, page_table_entry::PageTableEntry};
 use alloc::{collections::VecDeque, vec::Vec};
+use bit_field::BitField;
 use core::ops::Range;
 use core::ptr::slice_from_raw_parts_mut;
 
@@ -51,6 +52,7 @@ impl Mapping {
         // 解引用结束，entry位于最后一级页表
         Some(entry)
     }
+
     /// 找到虚拟页号对应的页表项，如果不存在则返回 None
     pub fn find_pte(&self, vpn: VirtualPageNumber) -> Option<&mut PageTableEntry> {
         let root_table_pa = self.root_ppn.start_address();

tornado-kernel/src/memory/mapping/memory_set.rs

@@ -154,14 +154,16 @@ impl MemorySet {
         // 映射 .user_text 段
         let user_text_len = _euser_text as usize - _suser_text as usize;
         let va_range = VirtualAddress(0)..VirtualAddress(user_text_len);
-        let pa_range = PhysicalAddress((_suser_text as usize).wrapping_sub(KERNEL_MAP_OFFSET))..PhysicalAddress((_euser_text as usize).wrapping_sub(KERNEL_MAP_OFFSET));
+        let pa_range = VirtualAddress(_suser_text as usize).physical_address_linear()..VirtualAddress(_euser_text as usize).physical_address_linear();
+        // let pa_range = PhysicalAddress((_suser_text as usize).wrapping_sub(KERNEL_MAP_OFFSET))..PhysicalAddress((_euser_text as usize).wrapping_sub(KERNEL_MAP_OFFSET));
         mapping.map_defined(&va_range, &pa_range, Flags::EXECUTABLE | Flags::READABLE | Flags::WRITABLE | Flags::USER);
         
-        // 映射 .user_data 段，目前这里作为用户态的栈使用
+        // 映射 .user_data 段
         let user_stack_len = _euser_data as usize - _suser_data as usize;
         assert_eq!(user_stack_len, PAGE_SIZE);
         let va_range = VirtualAddress(USER_STACK_BOTTOM_VA)..VirtualAddress(USER_STACK_BOTTOM_VA + user_stack_len);
-        let pa_range = PhysicalAddress((_suser_data as usize).wrapping_sub(KERNEL_MAP_OFFSET))..PhysicalAddress((_euser_data as usize).wrapping_sub(KERNEL_MAP_OFFSET));
+        let pa_range = VirtualAddress(_suser_data as usize).physical_address_linear()..VirtualAddress(_euser_data as usize).physical_address_linear();
+        // let pa_range = PhysicalAddress((_suser_data as usize).wrapping_sub(KERNEL_MAP_OFFSET))..PhysicalAddress((_euser_data as usize).wrapping_sub(KERNEL_MAP_OFFSET));
         mapping.map_defined(&va_range, &pa_range, Flags::READABLE | Flags::WRITABLE | Flags::USER);
         
         // 映射 _swap_frame

tornado-kernel/src/task/process.rs

@@ -41,6 +41,23 @@ impl Process {
         };
         Some(process)
     }
+    /// 创建一个用户进程
+    ///
+    /// 暂时和创建内核进程无太大区别，后续会思考这部分设计
+    pub fn new_user(memory_set: MemorySet) -> Option<Arc<Self>> {
+        let process = Arc::new(Process {
+            id: next_process_id(),
+            is_user: true,
+            inner: Mutex::new(ProcessInner {
+                memory_set
+            })
+        });
+        unsafe { 
+            KernelHartInfo::load_address_space_id(process.address_space_id());
+            KernelHartInfo::load_process(process.clone());
+        };
+        Some(process)
+    }
     // /// 得到进程编号
     // pub fn process_id(&self) -> ProcessId {
     //     self.id

tornado-kernel/src/user.rs

@@ -1,11 +1,13 @@
+use core::borrow::BorrowMut;
+
 /// 临时的用户态程序和数据
 
-use crate::memory::{self, PAGE_SIZE};
+use crate::memory::{self, PAGE_SIZE, MemorySet};
 use crate::trap;
 use crate::task;
 
 // 尝试进入用户态
-pub fn try_enter_user() -> ! {
+pub fn try_enter_user(kernel_stack_top: usize) -> ! {
     extern {
         // 用户陷入内核时候的中断处理函数
         fn _test_user_trap();
@@ -16,6 +18,7 @@ pub fn try_enter_user() -> ! {
    
     // 创建一个用户态映射
     let user_memory = memory::MemorySet::new_user().unwrap();
+    
     // 存放用户特权级切换上下文的虚拟地址
     let swap_cx_va = memory::VirtualAddress(memory::SWAP_CONTEXT_VA);
     // 存放用户特权级切换上下文的虚拟页号
@@ -37,21 +40,21 @@ pub fn try_enter_user() -> ! {
         .unwrap()
         .page_number();
     println!("user_entry_ppn: {:x?}", user_entry_ppn);
-    // let read_user_va: &mut [u16; 2] = unsafe {user_entry_ppn.start_address().deref_linear_static() };
-    // println!("code in user text:");
-    // for code in read_user_va {
-    //     println!("{:#x}", &code);
-    // }
     // 获取用户的satp寄存器
     let user_satp = user_memory.mapping.get_satp(user_memory.address_space_id);
-    let process = task::Process::new(user_memory).unwrap();
+    let process = task::Process::new_user(user_memory).unwrap();
+    // 用户态栈
+    let user_stack_handle = process.alloc_stack().expect("alloc user stack");
+    // 这里减 4 是因为映射的时候虚拟地址的右半边是不包含的
+    let user_stack_top = user_stack_handle.end.0 - 4;
+    println!("kernel stack top: {:#x}, user stack top: {:#x}", kernel_stack_top, user_stack_top);
     // 获取内核的satp寄存器
     let kernel_satp = riscv::register::satp::read().bits();
 
     // 往 SwapContext 写东西
     // _test_user_entry 由虚拟地址 0 映射到真实物理地址
     *swap_cx = trap::SwapContext::new_to_user(
-        kernel_satp, 0, 0, 0, memory::USER_STACK_BOTTOM_VA + PAGE_SIZE - 4, _test_user_trap as usize);
+        kernel_satp, 0, 0, kernel_stack_top, user_stack_top, _test_user_trap as usize);
     // println!("swap_cx.epc: {:#x}", swap_cx.epc);
     // println!("swap_cx.trap_handler: {:#x}", swap_cx.user_trap_handler);
     trap::switch_to_user(swap_cx, user_satp)
@@ -71,7 +74,7 @@ pub extern "C" fn test_user_entry() {
     loop {}
 }
 
-// 用户态栈
-#[export_name = "_user_stack_bottom"]
+// 用户态数据，这里是为了占位
+#[export_name = "_user_data"]
 #[link_section = ".user_data"]
 static _USER_STACK: [usize; PAGE_SIZE / 8] = [1; PAGE_SIZE / 8];