From ceb24341cdc8088fdd67404d424b82d2cc006b1b Mon Sep 17 00:00:00 2001
From: Kai Law <lawkai@vivo.com>
Date: Thu, 5 Mar 2026 11:35:24 +0800
Subject: [PATCH 1/2] Thread being retired should not be preempted

Fix https://github.com/vivoblueos/kernel/actions/runs/22700766319/job/65817293534.
```
panicked at ../../kernel/kernel/src/scheduler/mod.rs:269:9:
assertion `left == right` failed
  left: Err(4)
 right: Ok(())
Oops: assertion `left == right` failed
```
---
 kernel/src/scheduler/mod.rs | 18 ++++++++++--------
 1 file changed, 10 insertions(+), 8 deletions(-)

diff --git a/kernel/src/scheduler/mod.rs b/kernel/src/scheduler/mod.rs
index 31f14587..77963b3c 100644
--- a/kernel/src/scheduler/mod.rs
+++ b/kernel/src/scheduler/mod.rs
@@ -231,18 +231,18 @@ fn switch_current_thread(next: ThreadNode, old_sp: usize) -> usize {
     #[cfg(thread_stats)]
     old.increment_cycles(cycles);
     if old.state() == thread::RETIRED {
-        let cleanup = old.lock().take_cleanup();
-        if let Some(entry) = cleanup {
+        old.enable_preempt();
+        GlobalQueueVisitor::remove(&mut old);
+        if ThreadNode::strong_count(&old) != 1 {
+            // TODO: Add warning log that there are still references to the old thread.
+        }
+        if let Some(entry) = old.lock().take_cleanup() {
             match entry {
                 Entry::C(f) => f(),
                 Entry::Closure(f) => f(),
                 Entry::Posix(f, arg) => f(arg),
             }
         };
-        GlobalQueueVisitor::remove(&mut old);
-        if ThreadNode::strong_count(&old) != 1 {
-            // TODO: Add warning log that there are still references to the old thread.
-        }
     }
     old.set_saved_sp(old_sp);
     next_saved_sp
@@ -272,14 +272,16 @@ pub(crate) extern "C" fn relinquish_me_and_return_next_sp(old_sp: usize) -> usiz
 }
 
 pub fn retire_me() -> ! {
+    let retiring = current_thread_ref();
     #[cfg(procfs)]
     {
-        let _ = crate::vfs::trace_thread_close(current_thread());
+        let _ = crate::vfs::trace_thread_close(unsafe { Arc::clone_from(retiring) });
     }
     let next = next_ready_thread().map_or_else(idle::current_idle_thread, |v| v);
     debug_assert_eq!(next.state(), thread::READY);
     let mut hooks = ContextSwitchHookHolder::new(next);
-    let ok = current_thread_ref().transfer_state(thread::RUNNING, thread::RETIRED);
+    retiring.disable_preempt();
+    let ok = retiring.transfer_state(thread::RUNNING, thread::RETIRED);
     debug_assert_eq!(ok, Ok(()));
     arch::switch_context_with_hook(&mut hooks as *mut _);
     unreachable!("Retired thread should not reach here")

From 85237406ebfd24b2861c2f15093c2ff79ff2f5a7 Mon Sep 17 00:00:00 2001
From: Kai Law <lawkai@vivo.com>
Date: Thu, 5 Mar 2026 18:47:19 +0800
Subject: [PATCH 2/2] Address comment

---
 kernel/src/lib.rs           | 1 +
 kernel/src/scheduler/mod.rs | 1 -
 kernel/src/thread/mod.rs    | 5 +++++
 3 files changed, 6 insertions(+), 1 deletion(-)

diff --git a/kernel/src/lib.rs b/kernel/src/lib.rs
index de2877f0..a793aed7 100644
--- a/kernel/src/lib.rs
+++ b/kernel/src/lib.rs
@@ -174,6 +174,7 @@ mod tests {
     ) {
         unsafe {
             let t = TEST_THREADS[i].assume_init_ref();
+            t.set_preempt_count(0);
             let mut w = t.lock();
             let stack = &mut TEST_THREAD_STORAGES[i].stack;
             let Some(stack) = thread::Stack::from_raw(stack.rep.as_mut_ptr(), stack.rep.len())
diff --git a/kernel/src/scheduler/mod.rs b/kernel/src/scheduler/mod.rs
index 77963b3c..ef233c8c 100644
--- a/kernel/src/scheduler/mod.rs
+++ b/kernel/src/scheduler/mod.rs
@@ -231,7 +231,6 @@ fn switch_current_thread(next: ThreadNode, old_sp: usize) -> usize {
     #[cfg(thread_stats)]
     old.increment_cycles(cycles);
     if old.state() == thread::RETIRED {
-        old.enable_preempt();
         GlobalQueueVisitor::remove(&mut old);
         if ThreadNode::strong_count(&old) != 1 {
             // TODO: Add warning log that there are still references to the old thread.
diff --git a/kernel/src/thread/mod.rs b/kernel/src/thread/mod.rs
index 7b60185c..28c6b4d0 100644
--- a/kernel/src/thread/mod.rs
+++ b/kernel/src/thread/mod.rs
@@ -634,6 +634,11 @@ impl Thread {
         self.preempt_count.load(Ordering::Acquire)
     }
 
+    pub unsafe fn set_preempt_count(&self, val: Uint) -> &Self {
+        self.preempt_count.store(val, Ordering::Release);
+        self
+    }
+
     #[cfg(thread_stats)]
     #[inline]
     pub fn increment_cycles(&self, cycles: u64) {