Index: kernel/arch/mips32/src/mm/tlb.c
===================================================================
--- kernel/arch/mips32/src/mm/tlb.c	(revision 3a2b6364ba3983a631bdcfe110037871ba380b25)
+++ kernel/arch/mips32/src/mm/tlb.c	(revision 4acaa7c0d4fdaf4f08ad44578e5a437a7f8dc98f)
@@ -369,4 +369,6 @@
 	entry_hi_t hi;
 	pte_t *pte;
+
+	ASSERT(mutex_locked(&AS->lock));
 
 	hi.value = cp0_entry_hi_read();
Index: kernel/arch/ppc32/src/mm/tlb.c
===================================================================
--- kernel/arch/ppc32/src/mm/tlb.c	(revision 3a2b6364ba3983a631bdcfe110037871ba380b25)
+++ kernel/arch/ppc32/src/mm/tlb.c	(revision 4acaa7c0d4fdaf4f08ad44578e5a437a7f8dc98f)
@@ -67,4 +67,6 @@
     istate_t *istate, int *pfrc)
 {
+	ASSERT(mutex_locked(&as->lock));
+
 	/*
 	 * Check if the mapping exists in page tables.