Date: Tue, 26 Feb 2008 16:04:39 -0800
From: Andrew Morton <akpm@linux-foundation.org>
To: Evgeniy Polyakov <johnpol@2ka.mipt.ru>
Cc: Adrian Bunk <bunk@kernel.org>, Martin Michlmayr <tbm@cyrius.com>,
       linux-kernel@vger.kernel.org, Herbert Xu <herbert@gondor.apana.org.au>,
       Ralf Baechle <ralf@linux-mips.org>, linux-crypto@vger.kernel.org
Subject: Re: [2.6.25 patch] drivers/crypto/hifn_795x.c: fix 64bit division
Message-Id: <20080226160439.5941cc31.akpm@linux-foundation.org>
In-Reply-To: <20080226185240.GA2521@2ka.mipt.ru>
References: <20080226122100.GB22699@deprecation.cyrius.com>
	<20080226153421.GB10717@cs181133002.pp.htv.fi>
	<20080226185240.GA2521@2ka.mipt.ru>
Mime-Version: 1.0
Content-Type: text/plain; charset=US-ASCII
Content-Transfer-Encoding: 7bit
Sender: linux-kernel-owner@vger.kernel.org
Content-Length: 1184
Lines: 39

On Tue, 26 Feb 2008 21:52:40 +0300 Evgeniy Polyakov <johnpol@2ka.mipt.ru> wrote:

> Hi Adrian.
> 
> On Tue, Feb 26, 2008 at 05:34:21PM +0200, Adrian Bunk (bunk@kernel.org) wrote:
> > Using ndelay() with a 64bit variable as parameter can result in build 
> > errors like the following on some 32bit systems when it results in a 
> > 64bit division:
> > 
> > <--  snip  -->
> > 
> >  ...
> >   MODPOST 759 modules
> > ERROR: "__divdi3" [drivers/crypto/hifn_795x.ko] undefined!
> > 
> > <--  snip  -->
> > 
> > Reported by Martin Michlmayr.
> > 
> > Signed-off-by: Adrian Bunk <bunk@kernel.org>
> 
> Yep, ndelay() uses division, thanks a lot Adrian for spotting this.

hm.  Where?

> Herbert, please apply.
> 
> ACK.

udelay() might be exposed to the same problem.  It would be better to fix
ndelay() and udelay() rather than callers.  It is reasonable to pass a u64
into ndelay() and to expect the build to not explode.

(Geeze macros suck)
--
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/