Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261511AbVD0FZX (ORCPT ); Wed, 27 Apr 2005 01:25:23 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261558AbVD0FZX (ORCPT ); Wed, 27 Apr 2005 01:25:23 -0400 Received: from user-edvans3.msk.internet2.ru ([217.25.93.4]:6337 "EHLO vocord.com") by vger.kernel.org with ESMTP id S261511AbVD0FZO (ORCPT ); Wed, 27 Apr 2005 01:25:14 -0400 Subject: Re: [1/1] connector/CBUS: new messaging subsystem. Revision number next. From: Evgeniy Polyakov Reply-To: johnpol@2ka.mipt.ru To: Dmitry Torokhov Cc: netdev@oss.sgi.com, Greg KH , Jamal Hadi Salim , Kay Sievers , Herbert Xu , James Morris , Guillaume Thouvenin , linux-kernel@vger.kernel.org, Andrew Morton , Thomas Graf , Jay Lan In-Reply-To: <200504270016.34002.dtor_core@ameritech.net> References: <20050411125932.GA19538@uganda.factory.vocord.ru> <1114574809.14282.10.camel@uganda> <200504270016.34002.dtor_core@ameritech.net> Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="=-bJZJoCAojCcVx3lKkpfO" Organization: MIPT Date: Wed, 27 Apr 2005 09:32:06 +0400 Message-Id: <1114579926.14282.16.camel@uganda> Mime-Version: 1.0 X-Mailer: Evolution 2.0.4 (2.0.4-4) X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-1.4 (vocord.com [192.168.0.1]); Wed, 27 Apr 2005 09:24:35 +0400 (MSD) Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1786 Lines: 50 --=-bJZJoCAojCcVx3lKkpfO Content-Type: text/plain Content-Transfer-Encoding: quoted-printable On Wed, 2005-04-27 at 00:16 -0500, Dmitry Torokhov wrote: > On Tuesday 26 April 2005 23:06, Evgeniy Polyakov wrote: > > Let's clarify that we are talking about userspace->kernelspace > > direction. > > Only for that messages callback path is invoked. >=20 > What about kernelspace->userspace or kernelspace->kernelspace? > From what I see nothing stops kernel code from calling cn_netlink_send, > in fact your cbus does exactly that. So I am confused why you singled > out userspace->kernelspace direction. You miunderstand the code - cn_netlink_send() never ends up in callback invocation,=20 it can only deliver messages in kernelspace->userspace direction. kernelspace->userspace direction ends up adding buffer into socket queue, from which userspace may read data using recv() system call. There is no kernelspace->kernelspace sending possibility=20 except by creating new socket in userspace and sendmsg/recvmsg=20 interception/using, but that is the same as reading from userspace. --=20 Evgeniy Polyakov Crash is better than data corruption -- Arthur Grabowski --=-bJZJoCAojCcVx3lKkpfO Content-Type: application/pgp-signature; name=signature.asc Content-Description: This is a digitally signed message part -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.2.6 (GNU/Linux) iD8DBQBCbyPWIKTPhE+8wY0RApLCAJ9qHyMFNb74RL7jIyIF4vdYoXhLUQCglYZ7 kjZPt1yOlpG5DjL9rdk52mY= =MVUC -----END PGP SIGNATURE----- --=-bJZJoCAojCcVx3lKkpfO-- - 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/