Date: Sat, 11 Jul 2009 13:32:13 +0200 (CEST)
From: Julia Lawall <julia@diku.dk>
To: Jiri Slaby <jirislaby@gmail.com>
Cc: Jaswinder Singh Rajput <jaswinder@kernel.org>, gregkh@suse.de,
       devel@driverdev.osuosl.org, linux-kernel@vger.kernel.org,
       kernel-janitors@vger.kernel.org
Subject: Re: [PATCH 5/5] staging/otus: Move a dereference below a NULL test
In-Reply-To: <4A587245.1080304@gmail.com>
Message-ID: <Pine.LNX.4.64.0907111331170.31089@ask.diku.dk>
References: <Pine.LNX.4.64.0907110950510.29592@ask.diku.dk>  <4A584A94.5010105@gmail.com>
 <1247307444.3032.2.camel@hpdv5.satnam> <4A587245.1080304@gmail.com>
MIME-Version: 1.0
Content-Type: TEXT/PLAIN; charset=US-ASCII
Sender: linux-kernel-owner@vger.kernel.org
Content-Length: 1126
Lines: 35

On Sat, 11 Jul 2009, Jiri Slaby wrote:

> On 07/11/2009 12:17 PM, Jaswinder Singh Rajput wrote:
> > On Sat, 2009-07-11 at 10:17 +0200, Jiri Slaby wrote:
> >> On 07/11/2009 09:51 AM, Julia Lawall wrote:
> >>> --- a/drivers/staging/otus/wwrap.c
> >>> +++ b/drivers/staging/otus/wwrap.c
> >>> @@ -1016,12 +1016,13 @@ void kevent(struct work_struct *work)
> >>>  {
> >>>      struct usbdrv_private *macp =
> >>>                 container_of(work, struct usbdrv_private, kevent);
> >>> -    zdev_t *dev = macp->device;
> >>> +    zdev_t *dev;
> >>>  
> >>>      if (macp == NULL)
> >>>      {
> >>>          return;
> >>>      }
> >>
> >> The test is rather useless here.
> >>
> > 
> > Why useless, it should be non-null before setting to dev.
> 
> Even if work was NULL, macp won't be NULL.

work could be a small negative number such that calling container_of would 
return 0.

julia
--
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/