Index: kernel/arch/ppc32/src/mm/page.c
===================================================================
--- kernel/arch/ppc32/src/mm/page.c	(revision 4872160f9c176d257f1757469d1adec8033d95f9)
+++ kernel/arch/ppc32/src/mm/page.c	(revision cc70d575d08c55489c445500dcd2719668f8b1fe)
@@ -54,7 +54,9 @@
 	uintptr_t virtaddr = PA2KA(last_frame);
 	pfn_t i;
+	page_table_lock(AS_KERNEL, true);
 	for (i = 0; i < ADDR2PFN(ALIGN_UP(size, PAGE_SIZE)); i++)
 		page_mapping_insert(AS_KERNEL, virtaddr + PFN2ADDR(i),
 		    physaddr + PFN2ADDR(i), PAGE_NOT_CACHEABLE | PAGE_WRITE);
+	page_table_unlock(AS_KERNEL, true);
 	
 	last_frame = ALIGN_UP(last_frame + size, FRAME_SIZE);