fix sys_exec

kernel/src/arch/aarch64/interrupt/context.rs

@@ -32,7 +32,7 @@ impl TrapFrame {
         tf.spsr = 0b1101_00_0101; // To EL 1, enable IRQ
         tf
     }
-    fn new_user_thread(entry_addr: usize, sp: usize) -> Self {
+    pub fn new_user_thread(entry_addr: usize, sp: usize) -> Self {
         use core::mem::zeroed;
         let mut tf: Self = unsafe { zeroed() };
         tf.sp = sp;
@@ -40,9 +40,6 @@ impl TrapFrame {
         tf.spsr = 0b1101_00_0000; // To EL 0, enable IRQ
         tf
     }
-    pub fn is_user(&self) -> bool {
-        unimplemented!()
-    }
 }
 
 /// 新线程的内核栈初始内容
@@ -201,11 +198,6 @@ impl Context {
         }
         .push_at(kstack_top, ttbr)
     }
-    /// Called at a new user context
-    /// To get the init TrapFrame in sys_exec
-    pub unsafe fn get_init_tf(&self) -> TrapFrame {
-        (*(self.stack_top as *const InitStack)).tf.clone()
-    }
 }
 
 const ASID_MASK: u16 = 0xffff;

kernel/src/arch/mipsel/context.rs

@@ -76,7 +76,7 @@ impl TrapFrame {
     ///
     /// The new thread starts at `entry_addr`.
     /// The stack pointer will be set to `sp`.
-    fn new_user_thread(entry_addr: usize, sp: usize) -> Self {
+    pub fn new_user_thread(entry_addr: usize, sp: usize) -> Self {
         use core::mem::zeroed;
         let mut tf: Self = unsafe { zeroed() };
         tf.sp = sp;
@@ -269,9 +269,4 @@ impl Context {
         }
         .push_at(kstack_top)
     }
-
-    /// Used for getting the init TrapFrame of a new user context in `sys_exec`.
-    pub unsafe fn get_init_tf(&self) -> TrapFrame {
-        (*(self.sp as *const InitStack)).tf.clone()
-    }
 }

kernel/src/arch/riscv32/context.rs

@@ -40,7 +40,7 @@ impl TrapFrame {
     ///
     /// The new thread starts at `entry_addr`.
     /// The stack pointer will be set to `sp`.
-    fn new_user_thread(entry_addr: usize, sp: usize) -> Self {
+    pub fn new_user_thread(entry_addr: usize, sp: usize) -> Self {
         use core::mem::zeroed;
         let mut tf: Self = unsafe { zeroed() };
         tf.x[2] = sp;
@@ -289,9 +289,4 @@ impl Context {
         }
         .push_at(kstack_top)
     }
-
-    /// Used for getting the init TrapFrame of a new user context in `sys_exec`.
-    pub unsafe fn get_init_tf(&self) -> TrapFrame {
-        (*(self.sp as *const InitStack)).tf.clone()
-    }
 }

kernel/src/arch/x86_64/interrupt/trapframe.rs

@@ -73,7 +73,7 @@ impl TrapFrame {
         tf.fpstate_offset = 16; // skip restoring for first time
         tf
     }
-    fn new_user_thread(entry_addr: usize, rsp: usize) -> Self {
+    pub fn new_user_thread(entry_addr: usize, rsp: usize) -> Self {
         use crate::arch::gdt;
         let mut tf = TrapFrame::default();
         tf.cs = gdt::UCODE_SELECTOR.0 as usize;
@@ -234,9 +234,4 @@ impl Context {
         }
         .push_at(kstack_top)
     }
-    /// Called at a new user context
-    /// To get the init TrapFrame in sys_exec
-    pub unsafe fn get_init_tf(&self) -> TrapFrame {
-        (*(self.0 as *const InitStack)).tf.clone()
-    }
 }

kernel/src/process/structs.rs

@@ -126,13 +126,14 @@ impl Thread {
         })
     }
 
-    /// Make a new user process from ELF `data`
-    pub fn new_user(
+    /// Construct virtual memory of a new user process from ELF `data`.
+    /// Return `(MemorySet, entry_point, ustack_top)`
+    pub fn new_user_vm(
         data: &[u8],
         exec_path: &str,
         mut args: Vec<String>,
         envs: Vec<String>,
-    ) -> Box<Thread> {
+    ) -> (MemorySet, usize, usize) {
         // Parse ELF
         let elf = ElfFile::new(data).expect("failed to read elf");
 
@@ -159,22 +160,16 @@ impl Thread {
         // Check interpreter (for dynamic link)
         if let Ok(loader_path) = elf.get_interpreter() {
             // assuming absolute path
-            if let Ok(inode) = crate::fs::ROOT_INODE.lookup_follow(loader_path, FOLLOW_MAX_DEPTH) {
-                if let Ok(buf) = inode.read_as_vec() {
-                    // Elf loader should not have INTERP
-                    // No infinite loop
-                    args.insert(0, loader_path.into());
-                    args.insert(1, exec_path.into());
-                    args.remove(2);
-                    //info!("loader args: {:?}", args);
-                    //info!("loader envs: {:?}", envs);
-                    return Thread::new_user(buf.as_slice(), exec_path, args, envs);
-                } else {
-                    warn!("loader specified as {} but failed to read", &loader_path);
-                }
-            } else {
-                warn!("loader specified as {} but not found", &loader_path);
-            }
+            let inode = crate::fs::ROOT_INODE
+                .lookup_follow(loader_path, FOLLOW_MAX_DEPTH)
+                .expect("interpreter not found");
+            let buf = inode.read_as_vec().expect("failed to load interpreter");
+            // modify args for loader
+            args[0] = exec_path.into();
+            args.insert(0, loader_path.into());
+            // Elf loader should not have INTERP
+            // No infinite loop
+            return Thread::new_user_vm(buf.as_slice(), exec_path, args, envs);
         }
 
         // Make page table
@@ -216,6 +211,19 @@ impl Thread {
 
         trace!("{:#x?}", vm);
 
+        let entry_addr = elf.header.pt2.entry_point() as usize;
+        (vm, entry_addr, ustack_top)
+    }
+
+    /// Make a new user process from ELF `data`
+    pub fn new_user(
+        data: &[u8],
+        exec_path: &str,
+        mut args: Vec<String>,
+        envs: Vec<String>,
+    ) -> Box<Thread> {
+        let (vm, entry_addr, ustack_top) = Self::new_user_vm(data, exec_path, args, envs);
+
         let kstack = KernelStack::new();
 
         let mut files = BTreeMap::new();
@@ -253,8 +261,6 @@ impl Thread {
             )),
         );
 
-        let entry_addr = elf.header.pt2.entry_point() as usize;
-
         Box::new(Thread {
             context: unsafe {
                 Context::new_user_thread(entry_addr, ustack_top, kstack.top(), vm.token())
@@ -377,13 +383,6 @@ impl Process {
         }
         self.futexes.get(&uaddr).unwrap().clone()
     }
-    pub fn clone_for_exec(&mut self, other: &Self) {
-        self.files = other.files.clone();
-        self.cwd = other.cwd.clone();
-        self.pid = other.pid.clone();
-        self.parent = other.parent.clone();
-        self.threads = other.threads.clone();
-    }
 }
 
 trait ToMemoryAttr {

kernel/src/syscall/proc.rs

@@ -143,7 +143,7 @@ pub fn sys_exec(
         "exec:BEG: path: {:?}, argv: {:?}, envp: {:?}",
         path, argv, envp
     );
-    let proc = process();
+    let mut proc = process();
     let path = unsafe { proc.vm.check_and_clone_cstr(path)? };
     let args = unsafe { proc.vm.check_and_clone_cstr_array(argv)? };
     let envs = unsafe { proc.vm.check_and_clone_cstr_array(envp)? };
@@ -158,25 +158,29 @@ pub fn sys_exec(
         path, args, envs
     );
 
+    // Kill other threads
+    proc.threads.retain(|&tid| {
+        if tid != processor().tid() {
+            processor().manager().exit(tid, 1);
+        }
+        tid == processor().tid()
+    });
+
     // Read program file
     let inode = proc.lookup_inode(&path)?;
-    let buf = inode.read_as_vec()?;
+    let data = inode.read_as_vec()?;
 
     // Make new Thread
-    let mut thread = Thread::new_user(buf.as_slice(), &path, args, envs);
-    thread.proc.lock().clone_for_exec(&proc);
+    let (mut vm, entry_addr, ustack_top) = Thread::new_user_vm(data.as_slice(), &path, args, envs);
 
     // Activate new page table
     unsafe {
-        thread.proc.lock().vm.activate();
+        vm.activate();
     }
+    core::mem::swap(&mut proc.vm, &mut vm);
 
     // Modify the TrapFrame
-    *tf = unsafe { thread.context.get_init_tf() };
-
-    // Swap Context but keep KStack
-    ::core::mem::swap(&mut current_thread().kstack, &mut thread.kstack);
-    ::core::mem::swap(current_thread(), &mut *thread);
+    *tf = TrapFrame::new_user_thread(entry_addr, ustack_top);
 
     info!("exec:END: path: {:?}", path);
     Ok(0)