diff --git a/winsup/cygwin/ChangeLog b/winsup/cygwin/ChangeLog
index d6ec54bc6..863fb0c7f 100644
--- a/winsup/cygwin/ChangeLog
+++ b/winsup/cygwin/ChangeLog
@@ -1,3 +1,8 @@
+2002-09-24  Corinna Vinschen  <corinna@vinschen.de>
+
+	* mmap.cc (map_map): Add debug output.
+	(mmap64): Evaluate gran_len correctly even if offset isn't 0.
+
 2002-09-22  Christopher Faylor  <cgf@redhat.com>
 
 	More GNUify non-GNU formatted functions calls throughout.
diff --git a/winsup/cygwin/mmap.cc b/winsup/cygwin/mmap.cc
index bb45ac8e6..68d993cdd 100644
--- a/winsup/cygwin/mmap.cc
+++ b/winsup/cygwin/mmap.cc
@@ -140,6 +140,7 @@ mmap_record::map_map (__off64_t off, DWORD len)
       break;
     }
 
+  debug_printf ("map_map (fd=%d, off=%D, len=%d)", fdesc_, off, len);
   len = PAGE_CNT (len);
   if (fdesc_ == -1 && !off)
     {
@@ -468,7 +469,7 @@ mmap64 (caddr_t addr, size_t len, int prot, int flags, int fd, __off64_t off)
 
   /* Map always in multipliers of `granularity'-sized chunks. */
   __off64_t gran_off = off & ~(granularity - 1);
-  DWORD gran_len = howmany (len, granularity) * granularity;
+  DWORD gran_len = howmany (off + len, granularity) * granularity - gran_off;
 
   fhandler_base *fh;
   caddr_t base = addr;