From: Dan Carpenter <dan.carpenter@oracle.com>
To: kernel-janitors@vger.kernel.org
Subject: Re: [patch] staging: comedi: comedi_bond: silence a shift wrapping warning
Date: Wed, 21 Aug 2013 12:45:11 +0000 [thread overview]
Message-ID: <20130821124511.GZ4713@mwanda> (raw)
In-Reply-To: <20130821082727.GB5240@elgon.mountain>
On Wed, Aug 21, 2013 at 11:50:22AM +0100, Ian Abbott wrote:
> 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.
Ok. I'll make it a u64 in a v2 patch.
regards,
dan carpenter
next prev parent reply other threads:[~2013-08-21 12:45 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
2013-08-21 12:45 ` Dan Carpenter [this message]
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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