From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp1.linux-foundation.org ([140.211.169.13]) by bombadil.infradead.org with esmtps (Exim 4.69 #1 (Red Hat Linux)) id 1MdugT-0000Ci-2C for linux-mtd@lists.infradead.org; Wed, 19 Aug 2009 23:35:19 +0000 Date: Wed, 19 Aug 2009 16:34:26 -0700 From: Andrew Morton To: dimitri.gorokhovik@free.fr Subject: Re: [PATCH] nftl: fix offset alignments Message-Id: <20090819163426.fa90cf9f.akpm@linux-foundation.org> In-Reply-To: <785022442.3397251250633188592.JavaMail.root@zimbra3-e1.priv.proxad.net> References: <605152405.3397101250633087167.JavaMail.root@zimbra3-e1.priv.proxad.net> <785022442.3397251250633188592.JavaMail.root@zimbra3-e1.priv.proxad.net> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Cc: Scott James Remnant , David Brownell , David Woodhouse , linux-kernel@vger.kernel.org, Julia Lawall , linux-mtd@lists.infradead.org, Tim Gardner , David Woodhouse List-Id: Linux MTD discussion mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Wed, 19 Aug 2009 00:06:28 +0200 (CEST) dimitri.gorokhovik@free.fr wrote: > Arithmetic conversion in the mask computation makes the upper word > of the second argument passed down to mtd->read_oob(), be always 0 > (assuming 'offs' being a 64-bit signed long long type, and > 'mtd->writesize' being a 32-bit unsigned int type). > > This patch applies over the other one adding masking in nftl_write, > "nftl: write support is broken". > > Signed-off-by: > --- > > diff --git a/drivers/mtd/nftlcore.c b/drivers/mtd/nftlcore.c > index 665d3eb..d2fd066 100644 > --- a/drivers/mtd/nftlcore.c > +++ b/drivers/mtd/nftlcore.c > @@ -135,16 +135,17 @@ static void nftl_remove_dev(struct mtd_blktrans_dev *dev) > int nftl_read_oob(struct mtd_info *mtd, loff_t offs, size_t len, > size_t *retlen, uint8_t *buf) > { > + typeof(offs) mask = mtd->writesize - 1; I see no reason to use typeof here. Plain old loff_t mask = mtd->writesize - 1; would be more conventional. > struct mtd_oob_ops ops; > int res; > > ops.mode = MTD_OOB_PLACE; > - ops.ooboffs = offs & (mtd->writesize - 1); > + ops.ooboffs = offs & mask; > ops.ooblen = len; > ops.oobbuf = buf; > ops.datbuf = NULL; > > - res = mtd->read_oob(mtd, offs & ~(mtd->writesize - 1), &ops); > + res = mtd->read_oob(mtd, offs & ~mask, &ops); yup. From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753879AbZHSXff (ORCPT ); Wed, 19 Aug 2009 19:35:35 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753854AbZHSXfd (ORCPT ); Wed, 19 Aug 2009 19:35:33 -0400 Received: from smtp1.linux-foundation.org ([140.211.169.13]:56758 "EHLO smtp1.linux-foundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753718AbZHSXfc (ORCPT ); Wed, 19 Aug 2009 19:35:32 -0400 Date: Wed, 19 Aug 2009 16:34:26 -0700 From: Andrew Morton To: dimitri.gorokhovik@free.fr Cc: David Woodhouse , David Woodhouse , Tim Gardner , Scott James Remnant , Julia Lawall , David Brownell , linux-mtd@lists.infradead.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] nftl: fix offset alignments Message-Id: <20090819163426.fa90cf9f.akpm@linux-foundation.org> In-Reply-To: <785022442.3397251250633188592.JavaMail.root@zimbra3-e1.priv.proxad.net> References: <605152405.3397101250633087167.JavaMail.root@zimbra3-e1.priv.proxad.net> <785022442.3397251250633188592.JavaMail.root@zimbra3-e1.priv.proxad.net> X-Mailer: Sylpheed 2.4.8 (GTK+ 2.12.5; x86_64-redhat-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 19 Aug 2009 00:06:28 +0200 (CEST) dimitri.gorokhovik@free.fr wrote: > Arithmetic conversion in the mask computation makes the upper word > of the second argument passed down to mtd->read_oob(), be always 0 > (assuming 'offs' being a 64-bit signed long long type, and > 'mtd->writesize' being a 32-bit unsigned int type). > > This patch applies over the other one adding masking in nftl_write, > "nftl: write support is broken". > > Signed-off-by: > --- > > diff --git a/drivers/mtd/nftlcore.c b/drivers/mtd/nftlcore.c > index 665d3eb..d2fd066 100644 > --- a/drivers/mtd/nftlcore.c > +++ b/drivers/mtd/nftlcore.c > @@ -135,16 +135,17 @@ static void nftl_remove_dev(struct mtd_blktrans_dev *dev) > int nftl_read_oob(struct mtd_info *mtd, loff_t offs, size_t len, > size_t *retlen, uint8_t *buf) > { > + typeof(offs) mask = mtd->writesize - 1; I see no reason to use typeof here. Plain old loff_t mask = mtd->writesize - 1; would be more conventional. > struct mtd_oob_ops ops; > int res; > > ops.mode = MTD_OOB_PLACE; > - ops.ooboffs = offs & (mtd->writesize - 1); > + ops.ooboffs = offs & mask; > ops.ooblen = len; > ops.oobbuf = buf; > ops.datbuf = NULL; > > - res = mtd->read_oob(mtd, offs & ~(mtd->writesize - 1), &ops); > + res = mtd->read_oob(mtd, offs & ~mask, &ops); yup.