Handle backspace for k210/qemu platform && Add lots of user tests.

os/src/mm/frame_allocator.rs

@@ -48,6 +48,7 @@ impl StackFrameAllocator {
     pub fn init(&mut self, l: PhysPageNum, r: PhysPageNum) {
         self.current = l.0;
         self.end = r.0;
+        println!("last {} Physical Frames.", self.end - self.current);
     }
 }
 impl FrameAllocator for StackFrameAllocator {

os/src/mm/memory_set.rs

@@ -47,10 +47,6 @@ impl MemorySet {
             areas: Vec::new(),
         }
     }
-    #[allow(unused)]
-    pub fn dealloc_all_frames(&mut self) {
-        *self = Self::new_bare();
-    }
     pub fn token(&self) -> usize {
         self.page_table.token()
     }
@@ -217,7 +213,8 @@ impl MemorySet {
         self.page_table.translate(vpn)
     }
     pub fn clear(&mut self) {
-        *self = Self::new_bare();
+        //*self = Self::new_bare();
+        self.areas.clear();
     }
 }
 

os/src/syscall/process.rs

@@ -5,7 +5,7 @@ use crate::task::{
     current_user_token,
     add_task,
 };
-use crate::timer::get_time;
+use crate::timer::get_time_ms;
 use crate::mm::{
     translated_str,
     translated_refmut,
@@ -14,18 +14,7 @@ use crate::loader::get_app_data_by_name;
 use alloc::sync::Arc;
 
 pub fn sys_exit(exit_code: i32) -> ! {
-    // save exit code
-    let task = current_task().unwrap();
-
-    // ---- hold current PCB lock
-    task.acquire_inner_lock().exit_code = exit_code;
-    // ---- release current PCB lock
-
-    // this function will not return
-    // drop task manually to maintain rc correctly
-    drop(task);
-
-    exit_current_and_run_next();
+    exit_current_and_run_next(exit_code);
     panic!("Unreachable in sys_exit!");
 }
 
@@ -35,7 +24,7 @@ pub fn sys_yield() -> isize {
 }
 
 pub fn sys_get_time() -> isize {
-    get_time() as isize
+    get_time_ms() as isize
 }
 
 pub fn sys_getpid() -> isize {
@@ -68,11 +57,21 @@ pub fn sys_exec(path: *const u8) -> isize {
     }
 }
 
+/// If there is not a child process whose pid is same as given, return -1.
+/// Else if there is a child process but it is still running, return -2.
 pub fn sys_waitpid(pid: isize, exit_code_ptr: *mut i32) -> isize {
     let task = current_task().unwrap();
     // find a child process
+
     // ---- hold current PCB lock
     let mut inner = task.acquire_inner_lock();
+    if inner.children
+        .iter()
+        .find(|p| {pid == -1 || pid as usize == p.getpid()})
+        .is_none() {
+        return -1;
+        // ---- release current PCB lock
+    }
     let pair = inner.children
         .iter()
         .enumerate()
@@ -92,7 +91,7 @@ pub fn sys_waitpid(pid: isize, exit_code_ptr: *mut i32) -> isize {
         *translated_refmut(inner.memory_set.token(), exit_code_ptr) = exit_code;
         found_pid as isize
     } else {
-        -1
+        -2
     }
     // ---- release current PCB lock automatically
 }

os/src/task/mod.rs

@@ -42,14 +42,17 @@ pub fn suspend_current_and_run_next() {
     schedule(task_cx_ptr);
 }
 
-pub fn exit_current_and_run_next() {
+pub fn exit_current_and_run_next(exit_code: i32) {
     // take from Processor
     let task = take_current_task().unwrap();
     // **** hold current PCB lock
     let mut inner = task.acquire_inner_lock();
     // Change status to Zombie
     inner.task_status = TaskStatus::Zombie;
+    // Record exit code
+    inner.exit_code = exit_code;
     // move any child to its parent
+    // TODO: do not move to its parent but under initproc
 
     // ++++++ hold parent PCB lock here
     {

os/src/timer.rs

@@ -3,11 +3,16 @@ use crate::sbi::set_timer;
 use crate::config::CPU_FREQ;
 
 const TICKS_PER_SEC: usize = 100;
+const MSEC_PER_SEC: usize = 1000;
 
 pub fn get_time() -> usize {
     time::read()
 }
 
+pub fn get_time_ms() -> usize {
+    time::read() / (CPU_FREQ / MSEC_PER_SEC)
+}
+
 pub fn set_next_trigger() {
     set_timer(get_time() + CPU_FREQ / TICKS_PER_SEC);
 }

os/src/trap/mod.rs

@@ -67,13 +67,24 @@ pub fn trap_handler() -> ! {
             cx.x[10] = result as usize;
         }
         Trap::Exception(Exception::StoreFault) |
-        Trap::Exception(Exception::StorePageFault) => {
-            println!("[kernel] PageFault in application, bad addr = {:#x}, bad instruction = {:#x}, core dumped.", stval, current_trap_cx().sepc);
-            exit_current_and_run_next();
+        Trap::Exception(Exception::StorePageFault) |
+        Trap::Exception(Exception::InstructionFault) |
+        Trap::Exception(Exception::InstructionPageFault) |
+        Trap::Exception(Exception::LoadFault) |
+        Trap::Exception(Exception::LoadPageFault) => {
+            println!(
+                "[kernel] {:?} in application, bad addr = {:#x}, bad instruction = {:#x}, core dumped.",
+                scause.cause(),
+                stval,
+                current_trap_cx().sepc,
+            );
+            // page fault exit code
+            exit_current_and_run_next(-2);
         }
         Trap::Exception(Exception::IllegalInstruction) => {
             println!("[kernel] IllegalInstruction in application, core dumped.");
-            exit_current_and_run_next();
+            // illegal instruction exit code
+            exit_current_and_run_next(-3);
         }
         Trap::Interrupt(Interrupt::SupervisorTimer) => {
             set_next_trigger();