[PATCH] discontigmem fix

Try to avoid calling "pfn_to_page()" on invalid pfn's.  It used to be
legal, but the CONFIG_DISCONTIGMEM people want us to try to avoid it,
since they do magic stuff in their "pfn_to_page" translations.

diff --git a/mm/memory.c b/mm/memory.c
index a64f85fd3c337af25868dc534c4d237f5aee2a2c..d9b86809380f2376b975991db597a758008bc406 100644 (file)
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -292,8 +292,11 @@ skip_copy_pte_range:
                                 * and not mapped via rmap - duplicate the
                                 * mapping as is.
                                 */
-                               page = pfn_to_page(pfn);
-                               if (!pfn_valid(pfn) || PageReserved(page)) {
+                               page = NULL;
+                               if (pfn_valid(pfn)) 
+                                       page = pfn_to_page(pfn); 
+
+                               if (!page || PageReserved(page)) {
                                        set_pte(dst_pte, pte);
                                        goto cont_copy_pte_range_noset;
                                }