Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757016AbWKWI3l (ORCPT ); Thu, 23 Nov 2006 03:29:41 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1757222AbWKWI3l (ORCPT ); Thu, 23 Nov 2006 03:29:41 -0500 Received: from ecfrec.frec.bull.fr ([129.183.4.8]:26070 "EHLO ecfrec.frec.bull.fr") by vger.kernel.org with ESMTP id S1757016AbWKWI3k convert rfc822-to-8bit (ORCPT ); Thu, 23 Nov 2006 03:29:40 -0500 Date: Thu, 23 Nov 2006 09:28:05 +0100 From: =?ISO-8859-1?Q?S=E9bastien_Dugu=E9?= To: Andrew Morton Cc: linux-kernel , linux-aio , Suparna Bhattacharya , Christoph Hellwig , Zach Brown , Badari Pulavarty , Jean Pierre Dion , Ulrich Drepper Subject: Re: [PATCH -mm 3/4][AIO] - AIO completion signal notification Message-ID: <20061123092805.1408b0c6@frecb000686> In-Reply-To: <20061121170228.4412b572.akpm@osdl.org> References: <20061120151700.4a4f9407@frecb000686> <20061120152252.7e5a4229@frecb000686> <20061121170228.4412b572.akpm@osdl.org> X-Mailer: Sylpheed-Claws 2.6.0 (GTK+ 2.8.20; i486-pc-linux-gnu) Mime-Version: 1.0 X-MIMETrack: Itemize by SMTP Server on ECN002/FR/BULL(Release 5.0.12 |February 13, 2003) at 23/11/2006 09:35:07, Serialize by Router on ECN002/FR/BULL(Release 5.0.12 |February 13, 2003) at 23/11/2006 09:35:09, Serialize complete at 23/11/2006 09:35:09 Content-Transfer-Encoding: 8BIT Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1558 Lines: 53 On Tue, 21 Nov 2006 17:02:28 -0800 Andrew Morton wrote: > On Mon, 20 Nov 2006 15:22:52 +0100 > S__bastien Dugu__ wrote: > > > +static long aio_setup_sigevent(struct aio_notify *notify, > > + struct sigevent __user *user_event) > > +{ > > + sigevent_t event; > > + struct task_struct *target; > > + > > + if (copy_from_user(&event, user_event, sizeof (event))) > > + return -EFAULT; > > + > > + if (event.sigev_notify == SIGEV_NONE) > > + return 0; > > + > > + notify->notify = event.sigev_notify; > > + notify->signo = event.sigev_signo; > > + notify->value = event.sigev_value; > > + > > + read_lock(&tasklist_lock); > > + target = good_sigevent(&event); > > + > > + if (unlikely(!target || (target->flags & PF_EXITING))) > > + goto out_unlock; > > + > > + > > + > > + if (notify->notify == (SIGEV_SIGNAL|SIGEV_THREAD_ID)) { > > + /* > > + * This reference will be dropped in really_put_req() when > > + * we're done with the request. > > + */ > > + get_task_struct(target); > > + } > > It worries me that this function can save away a task_struct* without > having taken a reference against it. > OK. Does moving 'notify->target = target;' after the get_task_struct() will do, or am I missing something more subtle? Thanks, S?bastien. - 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/