diff --git arch/arm64/kernel/cpu.c arch/arm64/kernel/cpu.c
index d749024..759fc4e 100644
--- arch/arm64/kernel/cpu.c
+++ arch/arm64/kernel/cpu.c
@@ -1504,6 +1504,10 @@ out:
 void
 save_fp_regs(struct thread *thread)
 {
+	/* THIS IS PATCH FOR TEST */
+	if (thread->status == PS_EXITED) {
+		kprintf("%s: thread is going to exit. (NOT_FIXED)\n", __func__);
+	}
 	if (thread == &cpu_local_var(idle)) {
 		return;
 	}
diff --git arch/x86_64/kernel/cpu.c arch/x86_64/kernel/cpu.c
index 2ba5bd3..7512daa 100644
--- arch/x86_64/kernel/cpu.c
+++ arch/x86_64/kernel/cpu.c
@@ -1725,6 +1725,10 @@ out:
 void
 save_fp_regs(struct thread *thread)
 {
+	/* THIS IS PATCH FOR TEST */
+	if (thread->status == PS_EXITED) {
+		kprintf("%s: thread is going to exit. (NOT_FIXED)\n", __func__);
+	}
 	if (check_and_allocate_fp_regs(thread) != 0) {
 		// alloc error
 		return;