From 961902b93a2dd04813a43a012bcaf966f0ae3de1 Mon Sep 17 00:00:00 2001
From: Shengwen Cheng <shengwen1997.tw@gmail.com>
Date: Mon, 20 May 2024 23:40:17 +0800
Subject: [PATCH] Prevent underflow for preempt_count_dec()

---
 kernel/kernel.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/kernel/kernel.c b/kernel/kernel.c
index d46ab98..b2159e8 100644
--- a/kernel/kernel.c
+++ b/kernel/kernel.c
@@ -146,7 +146,8 @@ inline void preempt_count_inc(void)
 
 inline void preempt_count_dec(void)
 {
-    preempt_cnt--;
+    if (preempt_cnt > 0)
+        preempt_cnt--;
 }
 
 void preempt_disable(void)