--- zzzz-none-000/linux-2.4.17/include/asm-arm/mmu_context.h	2000-09-18 22:15:24.000000000 +0000
+++ sangam-fb-322/linux-2.4.17/include/asm-arm/mmu_context.h	2004-11-24 13:21:35.000000000 +0000
@@ -42,6 +42,10 @@
 switch_mm(struct mm_struct *prev, struct mm_struct *next,
 	  struct task_struct *tsk, unsigned int cpu)
 {
+#ifdef CONFIG_PREEMPT
+	if (preempt_is_disabled() == 0)
+		BUG();
+#endif
 	if (prev != next) {
 		cpu_switch_mm(next->pgd, tsk);
 		clear_bit(cpu, &prev->cpu_vm_mask);