diff -urNp 2.4.19pre9ac1/mm/mmap.c 2.4.19pre9ac2/mm/mmap.c
--- 2.4.19pre9ac1/mm/mmap.c	Thu May 30 16:08:06 2002
+++ 2.4.19pre9ac2/mm/mmap.c	Thu May 30 18:07:50 2002
@@ -485,6 +485,12 @@ static int vma_merge(struct mm_struct * 
 	return 0;
 }
 
+
+/*
+ *	NOTE: in this function we rely on TASK_SIZE being lower than
+ *	SIZE_MAX-PAGE_SIZE at least. I'm pretty sure that it is.
+ */
+
 unsigned long do_mmap_pgoff(struct file * file, unsigned long addr, unsigned long len,
 	unsigned long prot, unsigned long flags, unsigned long pgoff)
 {
@@ -500,12 +506,14 @@ unsigned long do_mmap_pgoff(struct file 
 	if (file && (!file->f_op || !file->f_op->mmap))
 		return -ENODEV;
 
-	if ((len = PAGE_ALIGN(len)) == 0)
+	if (!len)
 		return addr;
 
 	if (len > TASK_SIZE)
 		return -EINVAL;
 
+	len = PAGE_ALIGN(len);  /* This cannot be zero now */
+
 	/* offset overflow? */
 	if ((pgoff + (len >> PAGE_SHIFT)) < pgoff)
 		return -EINVAL;