commit 182d6096fe76b3d63b1151090cd07e60eca39302
Author: Mike Frysinger <vapier@gentoo.org>
Date:   Wed Jul 29 11:35:37 2015 -0400

    mmap64: fix undef warnings
    
    The only target that defines this is m68k, so move the existing fallback
    define up to avoid warnings on other systems.

diff --git a/sysdeps/unix/sysv/linux/mmap64.c b/sysdeps/unix/sysv/linux/mmap64.c
index 2c8304d860f19d58..fcaa6be1f41b3ffd 100644
--- a/sysdeps/unix/sysv/linux/mmap64.c
+++ b/sysdeps/unix/sysv/linux/mmap64.c
@@ -26,12 +26,12 @@
 #include <kernel-features.h>
 
 /* This is always 12, even on architectures where PAGE_SHIFT != 12.  */
+#ifndef MMAP2_PAGE_SHIFT
+# define MMAP2_PAGE_SHIFT 12
+#endif
 #if MMAP2_PAGE_SHIFT == -1
 static int page_shift;
 #else
-# ifndef MMAP2_PAGE_SHIFT
-#  define MMAP2_PAGE_SHIFT 12
-# endif
 #define page_shift MMAP2_PAGE_SHIFT
 #endif