Index: lib/profile/GCDAProfiling.c
===================================================================
--- lib/profile/GCDAProfiling.c
+++ lib/profile/GCDAProfiling.c
@@ -263,8 +263,9 @@
    * same GCDA. This can fail if the filesystem doesn't support it, but in that
    * case we'll just carry on with the old racy behaviour and hope for the best.
    */
-  flock(fd, LOCK_EX);
-  output_file = fdopen(fd, mode);
+  close(fd);
+  output_file = fopen(filename, mode);
+  flock(fileno(output_file), LOCK_EX);
 
   /* Initialize the write buffer. */
   write_buffer = NULL;
@@ -462,7 +463,7 @@
       unmap_file();
     }
 
-    flock(fd, LOCK_UN);
+    flock(fileno(output_file), LOCK_UN);
     fclose(output_file);
     output_file = NULL;
     write_buffer = NULL;