Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754004Ab0KTQN5 (ORCPT ); Sat, 20 Nov 2010 11:13:57 -0500 Received: from 81-174-11-161.staticnet.ngi.it ([81.174.11.161]:56731 "EHLO mail.enneenne.com" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1750972Ab0KTQN4 (ORCPT ); Sat, 20 Nov 2010 11:13:56 -0500 Date: Sat, 20 Nov 2010 17:13:51 +0100 From: Rodolfo Giometti To: Alexander Gordeev Cc: linux-kernel@vger.kernel.org, "Nikita V. Youshchenko" , linuxpps@ml.enneenne.com, Tejun Heo Message-ID: <20101120161351.GC13356@enneenne.com> Mail-Followup-To: Alexander Gordeev , linux-kernel@vger.kernel.org, "Nikita V. Youshchenko" , linuxpps@ml.enneenne.com, Tejun Heo References: <1a1ebcf97b2eb62548c34d2d8fc139c0703a9077.1290087480.git.lasaine@lvk.cs.msu.su> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1a1ebcf97b2eb62548c34d2d8fc139c0703a9077.1290087480.git.lasaine@lvk.cs.msu.su> Organization: GNU/Linux Device Drivers, Embedded Systems and Courses X-PGP-Key: gpg --keyserver keyserver.linux.it --recv-keys D25A5633 User-Agent: Mutt/1.5.20 (2009-06-14) X-SA-Exim-Connect-IP: 192.168.32.37 X-SA-Exim-Mail-From: giometti@enneenne.com Subject: Re: [PATCHv4 10/17] pps: use BUG_ON for kernel API safety checks X-SA-Exim-Version: 4.2.1 (built Wed, 25 Jun 2008 17:14:11 +0000) X-SA-Exim-Scanned: Yes (on mail.enneenne.com) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3126 Lines: 91 On Thu, Nov 18, 2010 at 07:01:03PM +0300, Alexander Gordeev wrote: > This way less overhead is involved when running production kernel. > If you want to debug a pps client module please define DEBUG to enable > the checks. > > Signed-off-by: Alexander Gordeev > --- > drivers/pps/kapi.c | 33 ++++++++++----------------------- > 1 files changed, 10 insertions(+), 23 deletions(-) > > diff --git a/drivers/pps/kapi.c b/drivers/pps/kapi.c > index fe832aa..54261c4 100644 > --- a/drivers/pps/kapi.c > +++ b/drivers/pps/kapi.c > @@ -81,25 +81,14 @@ struct pps_device *pps_register_source(struct pps_source_info *info, > int err; > > /* Sanity checks */ > - if ((info->mode & default_params) != default_params) { > - pr_err("pps: %s: unsupported default parameters\n", > - info->name); > - err = -EINVAL; > - goto pps_register_source_exit; > - } > - if ((info->mode & (PPS_ECHOASSERT | PPS_ECHOCLEAR)) != 0 && > - info->echo == NULL) { > - pr_err("pps: %s: echo function is not defined\n", > - info->name); > - err = -EINVAL; > - goto pps_register_source_exit; > - } > - if ((info->mode & (PPS_TSFMT_TSPEC | PPS_TSFMT_NTPFP)) == 0) { > - pr_err("pps: %s: unspecified time format\n", > - info->name); > - err = -EINVAL; > - goto pps_register_source_exit; > - } > + > + /* default_params should be supported */ > + BUG_ON((info->mode & default_params) != default_params); > + /* echo function should be defined if we are asked to call it */ > + BUG_ON((info->mode & (PPS_ECHOASSERT | PPS_ECHOCLEAR)) != 0 && > + info->echo == NULL); > + /* time format should be specified */ > + BUG_ON((info->mode & (PPS_TSFMT_TSPEC | PPS_TSFMT_NTPFP)) == 0); Nack. If the userland gives us some wrong parameters this is not the same of a kernel bug (which BUG_ON is used for). The userland must be notified about the wrong input. > /* Allocate memory for the new PPS source struct */ > pps = kzalloc(sizeof(struct pps_device), GFP_KERNEL); > @@ -179,10 +168,8 @@ void pps_event(struct pps_device *pps, struct pps_event_time *ts, int event, > int captured = 0; > struct pps_ktime ts_real; > > - if ((event & (PPS_CAPTUREASSERT | PPS_CAPTURECLEAR)) == 0) { > - dev_err(pps->dev, "unknown event (%x)\n", event); > - return; > - } > + /* check event type */ > + BUG_ON((event & (PPS_CAPTUREASSERT | PPS_CAPTURECLEAR)) == 0); Ack. This is a correct usage of BUG_ON. :) > dev_dbg(pps->dev, "PPS event at %ld.%09ld\n", > ts->ts_real.tv_sec, ts->ts_real.tv_nsec); > -- > 1.7.2.3 > Ciao, Rodolfo -- GNU/Linux Solutions e-mail: giometti@enneenne.com Linux Device Driver giometti@linux.it Embedded Systems phone: +39 349 2432127 UNIX programming skype: rodolfo.giometti Freelance ICT Italia - Consulente ICT Italia - www.consulenti-ict.it -- 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/