diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c
index 41824e7..295be1d 100644
--- a/arch/x86/mm/init_64.c
+++ b/arch/x86/mm/init_64.c
@@ -782,7 +782,7 @@
 	 * The rodata section (but not the kernel text!) should also be
 	 * not-executable.
 	 */
-	set_memory_nx(rodata_start, (end - start) >> PAGE_SHIFT);
+	set_memory_nx(rodata_start, (end - rodata_start) >> PAGE_SHIFT);
 
 	rodata_test();