diff --git a/src/process/process.rs b/src/process/process.rs
index f04347d..005fdb1 100644
--- a/src/process/process.rs
+++ b/src/process/process.rs
@@ -15,6 +15,9 @@ pub struct Process {
     pub(in process) status: Status,
     pub(in process) rsp: usize,
     pub(in process) is_user: bool,
+    /// Set (addr, value) after switch.
+    /// Used to set wait error code.
+    pub(in process) set_value: Option<(usize, usize)>,
 }
 
 pub type Pid = usize;
@@ -46,6 +49,7 @@ impl Process {
             status: Status::Ready,
             rsp,
             is_user: false,
+            set_value: None,
         }
     }
 
@@ -63,6 +67,7 @@ impl Process {
             status: Status::Running,
             rsp: 0, // will be set at first schedule
             is_user: false,
+            set_value: None,
         }
     }
 
@@ -133,6 +138,7 @@ impl Process {
             status: Status::Ready,
             rsp,
             is_user: true,
+            set_value: None,
         }
     }
 
@@ -173,6 +179,7 @@ impl Process {
             status: Status::Ready,
             rsp,
             is_user: true,
+            set_value: None,
         }
     }
 
diff --git a/src/process/processor.rs b/src/process/processor.rs
index 1ab7a16..aebe287 100644
--- a/src/process/processor.rs
+++ b/src/process/processor.rs
@@ -135,6 +135,10 @@ impl Processor {
             *from_pt = Some(old_table);
         }
 
+        if let Some((addr, value)) = to.set_value.take() {
+            unsafe { *(addr as *mut usize) = value; }
+        }
+
         info!("Processor: switch from {} to {}\n  rsp: {:#x} -> {:#x}", pid0, pid, rsp0, rsp);
     }
 
@@ -159,10 +163,13 @@ impl Processor {
         info!("Processor: {} exit, code: {}", pid, error_code);
         self.get_mut(pid).status = Status::Exited(error_code);
         if let Some(waiter) = self.find_waiter(pid) {
+            info!("  then wakeup {}", waiter);
+            self.next = Some(waiter);
             {
                 let p = self.get_mut(waiter);
+                p.set_value.as_mut().unwrap().1 = error_code;
                 p.status = Status::Ready;
-                p.set_return_value(error_code);
+                p.set_return_value(0);
             }
             // FIXME: remove this process
             self.get_mut(pid).parent = 0;
@@ -177,7 +184,7 @@ impl Processor {
     }
 
     /// Let current process wait for another
-    pub fn current_wait_for(&mut self, target: WaitTarget) -> WaitResult {
+    pub fn current_wait_for(&mut self, target: WaitTarget, code: *mut i32) -> WaitResult {
         info!("Processor: current {} wait for {:?}", self.current_pid, target);
         // Find one target process and it's exit code
         let (pid, exit_code) = match target {
@@ -197,11 +204,17 @@ impl Processor {
         if let Some(exit_code) = exit_code {
             info!("Processor: {} wait find and remove {}", self.current_pid, pid);
             self.procs.remove(&pid);
+            if !code.is_null() {
+                // WARNING: must be current! (page table)
+                unsafe { *code = exit_code as i32 };
+            }
             WaitResult::Ok(pid, exit_code)
         } else {
             info!("Processor: {} wait for {}", self.current_pid, pid);
             let current_pid = self.current_pid;
-            self.get_mut(current_pid).status = Status::Waiting(pid);
+            let p = self.get_mut(current_pid);
+            p.status = Status::Waiting(pid);
+            p.set_value = Some((code as usize, 0));
             WaitResult::Blocked
         }
     }
diff --git a/src/syscall.rs b/src/syscall.rs
index 06dbbd7..2176a32 100644
--- a/src/syscall.rs
+++ b/src/syscall.rs
@@ -98,14 +98,9 @@ fn sys_wait(pid: usize, code: *mut i32) -> i32 {
         0 => WaitTarget::AnyChild,
         _ => WaitTarget::Proc(pid),
     };
-    match processor.current_wait_for(target) {
-        WaitResult::Ok(pid, error_code) => {
-            if !code.is_null() {
-                unsafe { *code = error_code as i32 };
-            }
-            0 // pid as i32
-        },
-        WaitResult::Blocked => 0, // unused
+    match processor.current_wait_for(target, code) {
+        WaitResult::Ok(pid, error_code) => 0,
+        WaitResult::Blocked => 0,
         WaitResult::NotExist => -1,
     }
 }
diff --git a/status.md b/status.md
index 4e1747e..d0a088d 100644
--- a/status.md
+++ b/status.md
@@ -2,7 +2,7 @@
 - [ ] badarg
 - [ ] badsegment
 - [x] divzero
-- [ ] exit
+- [x] exit
 - [x] faultread
 - [x] faultreadkernel
 - [x] forktest
@@ -13,10 +13,28 @@
 - [ ] pgdir
 - [ ] priority
 - [ ] sh
-- [ ] sleep
+- [x] sleep
 - [x] sleepkill
 - [x] softint
 - [x] spin
 - [x] testbss
 - [x] waitkill
 - [x] yield
+
+## xv6 64bit user programs pass status
+- [ ] cat
+- [ ] chmod
+- [ ] echo
+- [ ] forktest
+- [ ] grep
+- [ ] init
+- [ ] kill
+- [ ] ln
+- [ ] ls
+- [ ] mkdir
+- [ ] rm
+- [ ] sh
+- [ ] stressfs
+- [ ] usertests
+- [ ] wc
+- [ ] zombie