--- linux/mm/mmap.c.orig	2002-12-11 14:27:04.000000000 +0100
+++ linux/mm/mmap.c	2002-12-11 14:28:09.000000000 +0100
@@ -421,14 +421,14 @@
 	if (file && (!file->f_op || !file->f_op->mmap))
 		return -ENODEV;
 
-	if (!len)
+	if (len == 0)
 		return addr;
 
-	if (len > TASK_SIZE)
-		return -EINVAL;
-
 	len = PAGE_ALIGN(len);
 
+	if (len > TASK_SIZE || len == 0)
+		return -EINVAL;
+
 	/* offset overflow? */
 	if ((pgoff + (len >> PAGE_SHIFT)) < pgoff)
 		return -EINVAL;