* [PATCH] nftl: fix offset alignments
[not found] <605152405.3397101250633087167.JavaMail.root@zimbra3-e1.priv.proxad.net>
@ 2009-08-18 22:06 ` dimitri.gorokhovik
2009-08-19 23:34 ` Andrew Morton
0 siblings, 1 reply; 3+ messages in thread
From: dimitri.gorokhovik @ 2009-08-18 22:06 UTC (permalink / raw)
To: David Woodhouse, David Woodhouse, Tim Gardner,
Scott James Remnant, Julia Lawall, David Brownell
Cc: linux-mtd, linux-kernel
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: <dimitri.gorokhovik@free.fr>
---
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;
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);
*retlen = ops.oobretlen;
return res;
}
@@ -155,16 +156,17 @@ int nftl_read_oob(struct mtd_info *mtd, loff_t offs, size_t len,
int nftl_write_oob(struct mtd_info *mtd, loff_t offs, size_t len,
size_t *retlen, uint8_t *buf)
{
+ typeof(offs) mask = mtd->writesize - 1;
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->write_oob(mtd, offs & ~(mtd->writesize - 1), &ops);
+ res = mtd->write_oob(mtd, offs & ~mask, &ops);
*retlen = ops.oobretlen;
return res;
}
@@ -177,17 +179,18 @@ int nftl_write_oob(struct mtd_info *mtd, loff_t offs, size_t len,
static int nftl_write(struct mtd_info *mtd, loff_t offs, size_t len,
size_t *retlen, uint8_t *buf, uint8_t *oob)
{
+ typeof(offs) mask = mtd->writesize - 1;
struct mtd_oob_ops ops;
int res;
ops.mode = MTD_OOB_PLACE;
- ops.ooboffs = offs & (mtd->writesize - 1);
+ ops.ooboffs = offs & mask;
ops.ooblen = mtd->oobsize;
ops.oobbuf = oob;
ops.datbuf = buf;
ops.len = len;
- res = mtd->write_oob(mtd, offs & ~(mtd->writesize - 1), &ops);
+ res = mtd->write_oob(mtd, offs & ~mask, &ops);
*retlen = ops.retlen;
return res;
}
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH] nftl: fix offset alignments
2009-08-18 22:06 ` [PATCH] nftl: fix offset alignments dimitri.gorokhovik
@ 2009-08-19 23:34 ` Andrew Morton
2009-08-20 21:13 ` dimitri.gorokhovik
0 siblings, 1 reply; 3+ messages in thread
From: Andrew Morton @ 2009-08-19 23:34 UTC (permalink / raw)
To: dimitri.gorokhovik
Cc: Scott James Remnant, David Brownell, David Woodhouse,
linux-kernel, Julia Lawall, linux-mtd, Tim Gardner,
David Woodhouse
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: <dimitri.gorokhovik@free.fr>
> ---
>
> 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.
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH] nftl: fix offset alignments
2009-08-19 23:34 ` Andrew Morton
@ 2009-08-20 21:13 ` dimitri.gorokhovik
0 siblings, 0 replies; 3+ messages in thread
From: dimitri.gorokhovik @ 2009-08-20 21:13 UTC (permalink / raw)
To: Andrew Morton
Cc: Scott James Remnant, David Brownell, David Woodhouse,
linux-kernel, Julia Lawall, linux-mtd, Tim Gardner,
David Woodhouse
"Andrew Morton" <akpm@linux-foundation.org> a écrit :
> On Wed, 19 Aug 2009 00:06:28 +0200 (CEST) dimitri.gorokhovik@free.fr
> wrote:
> ...
> > + 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.
I use typeoff in this way to guard masking code against absent-minded
modifications.
Attached is a corrected version as suggested.
Maybe Julia can come up with a clever rule for detecting unusual masking
operations automatically :-) ?
---
From: Dimitri Gorokhovik <dimitri.gorokhovik@free.fr>
Subject: nftl: fix offset alignments
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: Dimitri Gorokhovik <dimitri.gorokhovik@free.fr>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Tim Gardner <tim.gardner@canonical.com>
Cc: Scott James Remnant <scott@canonical.com>
---
drivers/mtd/nftlcore.c | 15 +++++++++------
1 files changed, 9 insertions(+), 6 deletions(-)
diff --git a/drivers/mtd/nftlcore.c b/drivers/mtd/nftlcore.c
index 665d3eb..1002e18 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)
{
+ loff_t mask = mtd->writesize - 1;
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);
*retlen = ops.oobretlen;
return res;
}
@@ -155,16 +156,17 @@ int nftl_read_oob(struct mtd_info *mtd, loff_t offs, size_t len,
int nftl_write_oob(struct mtd_info *mtd, loff_t offs, size_t len,
size_t *retlen, uint8_t *buf)
{
+ loff_t mask = mtd->writesize - 1;
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->write_oob(mtd, offs & ~(mtd->writesize - 1), &ops);
+ res = mtd->write_oob(mtd, offs & ~mask, &ops);
*retlen = ops.oobretlen;
return res;
}
@@ -177,17 +179,18 @@ int nftl_write_oob(struct mtd_info *mtd, loff_t offs, size_t len,
static int nftl_write(struct mtd_info *mtd, loff_t offs, size_t len,
size_t *retlen, uint8_t *buf, uint8_t *oob)
{
+ loff_t mask = mtd->writesize - 1;
struct mtd_oob_ops ops;
int res;
ops.mode = MTD_OOB_PLACE;
- ops.ooboffs = offs & (mtd->writesize - 1);
+ ops.ooboffs = offs & mask;
ops.ooblen = mtd->oobsize;
ops.oobbuf = oob;
ops.datbuf = buf;
ops.len = len;
- res = mtd->write_oob(mtd, offs & ~(mtd->writesize - 1), &ops);
+ res = mtd->write_oob(mtd, offs & ~mask, &ops);
*retlen = ops.retlen;
return res;
}
--
1.6.3.3
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2009-08-18 22:06 ` [PATCH] nftl: fix offset alignments dimitri.gorokhovik
2009-08-19 23:34 ` Andrew Morton
2009-08-20 21:13 ` dimitri.gorokhovik
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