+static bool
+install_page (struct addrspace *as, void *upage, void *kpage)
+{
+ /* Verify that there's not already a page at that virtual
+ address, then map our page there. */
+ if (pagedir_get_page (as->pagedir, upage) == NULL
+ && pagedir_set_page (as->pagedir, upage, kpage, true))
+ return true;
+ else
+ {
+ palloc_free (kpage);
+ return false;
+ }
+}
+