Messages in this thread Patch in this message | | | Date | Thu, 20 Aug 2009 23:13:46 +0200 (CEST) | From | dimitri.gorokhovik@free ... | Subject | Re: [PATCH] nftl: fix offset alignments |
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"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 -- 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/
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