Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932671AbXAJCoJ (ORCPT ); Tue, 9 Jan 2007 21:44:09 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932676AbXAJCoJ (ORCPT ); Tue, 9 Jan 2007 21:44:09 -0500 Received: from turing-police.cc.vt.edu ([128.173.14.107]:46398 "EHLO turing-police.cc.vt.edu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932671AbXAJCoH (ORCPT ); Tue, 9 Jan 2007 21:44:07 -0500 Message-Id: <200701100243.l0A2hZxH013254@turing-police.cc.vt.edu> X-Mailer: exmh version 2.7.2 01/07/2005 with nmh-1.2 To: Amit Choudhary Cc: Pekka Enberg , Hua Zhong , Christoph Hellwig , Linux Kernel Subject: Re: [PATCH] include/linux/slab.h: new KFREE() macro. In-Reply-To: Your message of "Tue, 09 Jan 2007 16:00:51 PST." <802696.41460.qm@web55611.mail.re4.yahoo.com> From: Valdis.Kletnieks@vt.edu References: <802696.41460.qm@web55611.mail.re4.yahoo.com> Mime-Version: 1.0 Content-Type: multipart/signed; boundary="==_Exmh_1168397015_27952P"; micalg=pgp-sha1; protocol="application/pgp-signature" Content-Transfer-Encoding: 7bit Date: Tue, 09 Jan 2007 21:43:35 -0500 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1357 Lines: 41 --==_Exmh_1168397015_27952P Content-Type: text/plain; charset=us-ascii On Tue, 09 Jan 2007 16:00:51 PST, Amit Choudhary said: > What did you understand when I wrote that "if you access the same memory again using the variable > 'x"? > > Using variable 'x' means using variable 'x' and not variable 'y'. Right - but in real-world code, 'y' is the actual problem. > Did I ever say that it fixes that kind of bug? The point you're missing is that you're "fixing" a failure mode that in general isn't seen, and ignoring the failure mode that *is* seen. > Dereferencing 'x' means dereferencing 'x' and not dereferencing 'y'. And neither "x" nor "y" is "the set of all still-live pointers to already-freed memory" - which is why your proposal doesn't actually do anything effective. --==_Exmh_1168397015_27952P Content-Type: application/pgp-signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.6 (GNU/Linux) Comment: Exmh version 2.5 07/13/2001 iD8DBQFFpFLXcC3lWbTT17ARAoDzAKDQi6zGAFISialMr+wkkBNjaQ9BvwCgtc6p J2HFLU2pBlFURBKGk/1NZn4= =yAju -----END PGP SIGNATURE----- --==_Exmh_1168397015_27952P-- - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/