From: Miquel Raynal <miquel.raynal@bootlin.com> To: YouChing Lin <ycllin@mxic.com.tw> Cc: vigneshr@ti.com, juliensu@mxic.com.tw, linux-mtd@lists.infradead.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 1/2] mtd: nand: ecc-bch: Fix the size of calc_buf/code_buf of the BCH Date: Thu, 10 Dec 2020 22:33:33 +0100 [thread overview] Message-ID: <20201210223333.204062b1@xps13> (raw) In-Reply-To: <1607570529-22341-2-git-send-email-ycllin@mxic.com.tw> Hi YouChing, YouChing Lin <ycllin@mxic.com.tw> wrote on Thu, 10 Dec 2020 11:22:08 +0800: > If eccbyte exceeds 64 bytes, the read operation will get wrong results. > For example: Flash with a page size of 4096 bytes (eccbyte: 104 bytes). > During the read operation, after executing nand_ecc_sw_bch_calculate(), > since the calc_buf/code_buf ranges overlap each other, the last three > steps of ecc_code (read from oob) will be changed. > > The root cause is that the size of calc_buf/code_buf is limited to 64 > bytes, although sizeof(mtd->oobsize) returns 4, kzalloc() will allocate > 64 bytes (cache size alignment). > > So we correct the size of calc_buf/code_buf to mtd->oobsize. > > Signed-off-by: YouChing Lin <ycllin@mxic.com.tw> > --- > drivers/mtd/nand/ecc-sw-bch.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/drivers/mtd/nand/ecc-sw-bch.c b/drivers/mtd/nand/ecc-sw-bch.c > index 4d8a979..0a0ac11 100644 > --- a/drivers/mtd/nand/ecc-sw-bch.c > +++ b/drivers/mtd/nand/ecc-sw-bch.c > @@ -237,8 +237,8 @@ int nand_ecc_sw_bch_init_ctx(struct nand_device *nand) > > engine_conf->code_size = code_size; > engine_conf->nsteps = nsteps; > - engine_conf->calc_buf = kzalloc(sizeof(mtd->oobsize), GFP_KERNEL); > - engine_conf->code_buf = kzalloc(sizeof(mtd->oobsize), GFP_KERNEL); > + engine_conf->calc_buf = kzalloc(mtd->oobsize, GFP_KERNEL); > + engine_conf->code_buf = kzalloc(mtd->oobsize, GFP_KERNEL); Very nice catch! If you don't mind I will merge this fix with the faulty commit (still in next) and I will also bring the fix to Hamming which will suffer from the same error. Then I will apply the second patch. > if (!engine_conf->calc_buf || !engine_conf->code_buf) { > ret = -ENOMEM; > goto free_bufs; Thanks, Miquèl
WARNING: multiple messages have this Message-ID (diff)
From: Miquel Raynal <miquel.raynal@bootlin.com> To: YouChing Lin <ycllin@mxic.com.tw> Cc: juliensu@mxic.com.tw, linux-mtd@lists.infradead.org, vigneshr@ti.com, linux-kernel@vger.kernel.org Subject: Re: [PATCH 1/2] mtd: nand: ecc-bch: Fix the size of calc_buf/code_buf of the BCH Date: Thu, 10 Dec 2020 22:33:33 +0100 [thread overview] Message-ID: <20201210223333.204062b1@xps13> (raw) In-Reply-To: <1607570529-22341-2-git-send-email-ycllin@mxic.com.tw> Hi YouChing, YouChing Lin <ycllin@mxic.com.tw> wrote on Thu, 10 Dec 2020 11:22:08 +0800: > If eccbyte exceeds 64 bytes, the read operation will get wrong results. > For example: Flash with a page size of 4096 bytes (eccbyte: 104 bytes). > During the read operation, after executing nand_ecc_sw_bch_calculate(), > since the calc_buf/code_buf ranges overlap each other, the last three > steps of ecc_code (read from oob) will be changed. > > The root cause is that the size of calc_buf/code_buf is limited to 64 > bytes, although sizeof(mtd->oobsize) returns 4, kzalloc() will allocate > 64 bytes (cache size alignment). > > So we correct the size of calc_buf/code_buf to mtd->oobsize. > > Signed-off-by: YouChing Lin <ycllin@mxic.com.tw> > --- > drivers/mtd/nand/ecc-sw-bch.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/drivers/mtd/nand/ecc-sw-bch.c b/drivers/mtd/nand/ecc-sw-bch.c > index 4d8a979..0a0ac11 100644 > --- a/drivers/mtd/nand/ecc-sw-bch.c > +++ b/drivers/mtd/nand/ecc-sw-bch.c > @@ -237,8 +237,8 @@ int nand_ecc_sw_bch_init_ctx(struct nand_device *nand) > > engine_conf->code_size = code_size; > engine_conf->nsteps = nsteps; > - engine_conf->calc_buf = kzalloc(sizeof(mtd->oobsize), GFP_KERNEL); > - engine_conf->code_buf = kzalloc(sizeof(mtd->oobsize), GFP_KERNEL); > + engine_conf->calc_buf = kzalloc(mtd->oobsize, GFP_KERNEL); > + engine_conf->code_buf = kzalloc(mtd->oobsize, GFP_KERNEL); Very nice catch! If you don't mind I will merge this fix with the faulty commit (still in next) and I will also bring the fix to Hamming which will suffer from the same error. Then I will apply the second patch. > if (!engine_conf->calc_buf || !engine_conf->code_buf) { > ret = -ENOMEM; > goto free_bufs; Thanks, Miquèl ______________________________________________________ Linux MTD discussion mailing list http://lists.infradead.org/mailman/listinfo/linux-mtd/
next prev parent reply other threads:[~2020-12-10 21:34 UTC|newest] Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top 2020-12-10 3:22 [PATCH 0/2] mtd: spinand: add support for MX35LFxG24AD & Fix bug of BCH YouChing Lin 2020-12-10 3:22 ` YouChing Lin 2020-12-10 3:22 ` [PATCH 1/2] mtd: nand: ecc-bch: Fix the size of calc_buf/code_buf of the BCH YouChing Lin 2020-12-10 3:22 ` YouChing Lin 2020-12-10 21:33 ` Miquel Raynal [this message] 2020-12-10 21:33 ` Miquel Raynal 2020-12-11 1:20 ` ycllin 2020-12-11 1:20 ` ycllin 2020-12-10 3:22 ` [PATCH 2/2] mtd: spinand: macronix: Add support for MX35LFxG24AD YouChing Lin 2020-12-10 3:22 ` YouChing Lin 2020-12-10 21:38 ` Miquel Raynal 2020-12-10 21:38 ` Miquel Raynal
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