From: Ian Abbott <abbotti@mev.co.uk>
To: kernel-janitors@vger.kernel.org
Subject: Re: [patch] staging: comedi: comedi_bond: silence a shift wrapping warning
Date: Wed, 21 Aug 2013 10:50:22 +0000 [thread overview]
Message-ID: <52149B6E.6090809@mev.co.uk> (raw)
In-Reply-To: <20130821082727.GB5240@elgon.mountain>
On 2013-08-21 09:27, Dan Carpenter wrote:
> We set this using:
>
> devs_closed |= (0x1 << bdev->minor)
>
> Since 0x1 is an int then only the lower 32 bits are usable before we hit
> a shift wrapping bug. There are some static checkers which complain
> about this. I've silenced the warning by making devs_closed a 32 bit
> number.
>
> 32 bits should be enough for anybody.
Not really, as bdev->minor will be in the range 0 to 47 inclusive (0 to
COMEDI_NUM_BOARD_MINORS-1). Of course, an unsigned long is insufficient
too on a 32-bit system.
>
> Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
>
> diff --git a/drivers/staging/comedi/drivers/comedi_bond.c b/drivers/staging/comedi/drivers/comedi_bond.c
> index 7e20bf0..8f6c942 100644
> --- a/drivers/staging/comedi/drivers/comedi_bond.c
> +++ b/drivers/staging/comedi/drivers/comedi_bond.c
> @@ -335,7 +335,7 @@ static int bonding_attach(struct comedi_device *dev,
> static void bonding_detach(struct comedi_device *dev)
> {
> struct comedi_bond_private *devpriv = dev->private;
> - unsigned long devs_closed = 0;
> + unsigned int devs_closed = 0;
>
> if (devpriv) {
> while (devpriv->ndevs-- && devpriv->devs) {
>
--
-=( Ian Abbott @ MEV Ltd. E-mail: <abbotti@mev.co.uk> )=-
-=( Tel: +44 (0)161 477 1898 FAX: +44 (0)161 718 3587 )=-
next prev parent reply other threads:[~2013-08-21 10:50 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-08-21 8:27 [patch] staging: comedi: comedi_bond: silence a shift wrapping warning Dan Carpenter
2013-08-21 10:50 ` Ian Abbott [this message]
2013-08-21 12:45 ` Dan Carpenter
2013-08-21 16:44 ` Ian Abbott
2013-08-21 20:08 ` Dan Carpenter
2013-08-22 19:21 ` Ian Abbott
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