From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Tue, 15 Oct 2002 22:02:41 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Tue, 15 Oct 2002 22:02:41 -0400 Received: from pizda.ninka.net ([216.101.162.242]:39339 "EHLO pizda.ninka.net") by vger.kernel.org with ESMTP id ; Tue, 15 Oct 2002 22:02:40 -0400 Date: Tue, 15 Oct 2002 19:00:19 -0700 (PDT) Message-Id: <20021015.190019.41374479.davem@redhat.com> To: weigand@immd1.informatik.uni-erlangen.de Cc: levon@movementarian.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] [8/7] oprofile - dcookies need to use u32 From: "David S. Miller" In-Reply-To: <200210160156.DAA25005@faui11.informatik.uni-erlangen.de> References: <200210160156.DAA25005@faui11.informatik.uni-erlangen.de> X-FalunGong: Information control. X-Mailer: Mew version 2.1 on Emacs 21.1 / Mule 5.0 (SAKAKI) Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org From: Ulrich Weigand Date: Wed, 16 Oct 2002 03:56:10 +0200 (MET DST) + return (u32)dentry; Um, isn't this supposed to uniquely identify the dentry? On a platform with 64-bit pointers there's now the theoretical possibility of different dentries getting the same cookie ... That's true. We dealt with this (trying to use a kernel pointer as a cache held by userspace) in tcp_diag by making the actual object opaque. It was actually two u32's, and that way it worked independant of kernel vs. user word size.