Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > linux.kernel > #1480092 > unrolled thread

[PATCH BUGFIX] mtd: nand: mxc: fix obiwan error in mxc_nand_v[12]_ooblayout_free() functions

Back to article view | Back to linux.kernel

Contents

  [PATCH BUGFIX] mtd: nand: mxc: fix obiwan error in mxc_nand_v[12]_ooblayout_free() functions Lothar Waßmann <LW@KARO-electronics.de> - 2016-09-09 17:10 +0200
    Re: [PATCH BUGFIX] mtd: nand: mxc: fix obiwan error in  mxc_nand_v[12]_ooblayout_free() functions Boris Brezillon <boris.brezillon@free-electrons.com> - 2016-09-15 18:10 +0200
      Re: [PATCH BUGFIX] mtd: nand: mxc: fix obiwan error in  mxc_nand_v[12]_ooblayout_free() functions Lothar Waßmann <LW@KARO-electronics.de> - 2016-09-16 10:20 +0200
        Re: [PATCH BUGFIX] mtd: nand: mxc: fix obiwan error in  mxc_nand_v[12]_ooblayout_free() functions Boris Brezillon <boris.brezillon@free-electrons.com> - 2016-09-19 11:40 +0200

#1480092 — [PATCH BUGFIX] mtd: nand: mxc: fix obiwan error in mxc_nand_v[12]_ooblayout_free() functions

commit a894cf6c5a82 ("mtd: nand: mxc: switch to mtd_ooblayout_ops")
introduced a regression accessing the OOB area from the mxc_nand
driver due to an Obiwan error in the mxc_nand_v[12]_ooblayout_free()
functions. They report a bogus oobregion { 64, 7 } which leads to
errors accessing bogus data when reading the oob area.

Prior to the commit the mtd-oobtest module could be run without any
errors. With the offending commit, this test fails with results like:
|Running mtd-oobtest
|
|=================================================
|mtd_oobtest: MTD device: 5
|mtd_oobtest: MTD device size 524288, eraseblock size 131072, page size 2048, count of eraseblocks 4, pages per eraseblock 64, OOB size 64
|mtd_test: scanning for bad eraseblocks
|mtd_test: scanned 4 eraseblocks, 0 are bad
|mtd_oobtest: test 1 of 5
|mtd_oobtest: writing OOBs of whole device
|mtd_oobtest: written up to eraseblock 0
|mtd_oobtest: written 4 eraseblocks
|mtd_oobtest: verifying all eraseblocks
|mtd_oobtest: error @addr[0x0:0x19] 0x9a -> 0x78 diff 0xe2
|mtd_oobtest: error @addr[0x0:0x1a] 0xcc -> 0x0 diff 0xcc
|mtd_oobtest: error @addr[0x0:0x1b] 0xe0 -> 0x85 diff 0x65
|mtd_oobtest: error @addr[0x0:0x1c] 0x60 -> 0x62 diff 0x2
|mtd_oobtest: error @addr[0x0:0x1d] 0x69 -> 0x45 diff 0x2c
|mtd_oobtest: error @addr[0x0:0x1e] 0xcd -> 0xa0 diff 0x6d
|mtd_oobtest: error @addr[0x0:0x1f] 0xf2 -> 0x60 diff 0x92
|mtd_oobtest: error: verify failed at 0x0
[...]

Signed-off-by: Lothar Waßmann <LW@KARO-electronics.de>
---
 drivers/mtd/nand/mxc_nand.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/mtd/nand/mxc_nand.c b/drivers/mtd/nand/mxc_nand.c
index 5173fad..fdee907 100644
--- a/drivers/mtd/nand/mxc_nand.c
+++ b/drivers/mtd/nand/mxc_nand.c
@@ -893,7 +893,7 @@ static int mxc_v1_ooblayout_free(struct mtd_info *mtd, int section,
 {
 	struct nand_chip *nand_chip = mtd_to_nand(mtd);
 
-	if (section > nand_chip->ecc.steps)
+	if (section >= nand_chip->ecc.steps)
 		return -ERANGE;
 
 	if (!section) {
@@ -943,7 +943,7 @@ static int mxc_v2_ooblayout_free(struct mtd_info *mtd, int section,
 	struct nand_chip *nand_chip = mtd_to_nand(mtd);
 	int stepsize = nand_chip->ecc.bytes == 9 ? 16 : 26;
 
-	if (section > nand_chip->ecc.steps)
+	if (section >= nand_chip->ecc.steps)
 		return -ERANGE;
 
 	if (!section) {
-- 
2.1.4

[toc] | [next] | [standalone]

#1484374 — Re: [PATCH BUGFIX] mtd: nand: mxc: fix obiwan error in mxc_nand_v[12]_ooblayout_free() functions

Hi Lothar,

On Fri,  9 Sep 2016 16:44:11 +0200
Lothar Waßmann <LW@KARO-electronics.de> wrote:

> commit a894cf6c5a82 ("mtd: nand: mxc: switch to mtd_ooblayout_ops")
> introduced a regression accessing the OOB area from the mxc_nand
> driver due to an Obiwan error in the mxc_nand_v[12]_ooblayout_free()
> functions. They report a bogus oobregion { 64, 7 } which leads to
> errors accessing bogus data when reading the oob area.
> 
> Prior to the commit the mtd-oobtest module could be run without any
> errors. With the offending commit, this test fails with results like:
> |Running mtd-oobtest
> |
> |=================================================
> |mtd_oobtest: MTD device: 5
> |mtd_oobtest: MTD device size 524288, eraseblock size 131072, page size 2048, count of eraseblocks 4, pages per eraseblock 64, OOB size 64
> |mtd_test: scanning for bad eraseblocks
> |mtd_test: scanned 4 eraseblocks, 0 are bad
> |mtd_oobtest: test 1 of 5
> |mtd_oobtest: writing OOBs of whole device
> |mtd_oobtest: written up to eraseblock 0
> |mtd_oobtest: written 4 eraseblocks
> |mtd_oobtest: verifying all eraseblocks
> |mtd_oobtest: error @addr[0x0:0x19] 0x9a -> 0x78 diff 0xe2
> |mtd_oobtest: error @addr[0x0:0x1a] 0xcc -> 0x0 diff 0xcc
> |mtd_oobtest: error @addr[0x0:0x1b] 0xe0 -> 0x85 diff 0x65
> |mtd_oobtest: error @addr[0x0:0x1c] 0x60 -> 0x62 diff 0x2
> |mtd_oobtest: error @addr[0x0:0x1d] 0x69 -> 0x45 diff 0x2c
> |mtd_oobtest: error @addr[0x0:0x1e] 0xcd -> 0xa0 diff 0x6d
> |mtd_oobtest: error @addr[0x0:0x1f] 0xf2 -> 0x60 diff 0x92
> |mtd_oobtest: error: verify failed at 0x0
> [...]
> 
> Signed-off-by: Lothar Waßmann <LW@KARO-electronics.de>
> ---
>  drivers/mtd/nand/mxc_nand.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/mtd/nand/mxc_nand.c b/drivers/mtd/nand/mxc_nand.c
> index 5173fad..fdee907 100644
> --- a/drivers/mtd/nand/mxc_nand.c
> +++ b/drivers/mtd/nand/mxc_nand.c
> @@ -893,7 +893,7 @@ static int mxc_v1_ooblayout_free(struct mtd_info *mtd, int section,
>  {
>  	struct nand_chip *nand_chip = mtd_to_nand(mtd);
>  
> -	if (section > nand_chip->ecc.steps)
> +	if (section >= nand_chip->ecc.steps)
>  		return -ERANGE;

Hm, looking at the commit you're pointing to, it seems that this test
is correct (we have X + 1 free sections, where X is the number of ECC
steps).

>  
>  	if (!section) {
> @@ -943,7 +943,7 @@ static int mxc_v2_ooblayout_free(struct mtd_info *mtd, int section,
>  	struct nand_chip *nand_chip = mtd_to_nand(mtd);
>  	int stepsize = nand_chip->ecc.bytes == 9 ? 16 : 26;
>  
> -	if (section > nand_chip->ecc.steps)
> +	if (section >= nand_chip->ecc.steps)
>  		return -ERANGE;

Yep, this one is a real bug.

>  
>  	if (!section) {

[toc] | [prev] | [next] | [standalone]

#1484773 — Re: [PATCH BUGFIX] mtd: nand: mxc: fix obiwan error in mxc_nand_v[12]_ooblayout_free() functions

Hi,

On Thu, 15 Sep 2016 18:06:05 +0200 Boris Brezillon wrote:
> Hi Lothar,
> 
> On Fri,  9 Sep 2016 16:44:11 +0200
> Lothar Waßmann <LW@KARO-electronics.de> wrote:
> 
> > commit a894cf6c5a82 ("mtd: nand: mxc: switch to mtd_ooblayout_ops")
> > introduced a regression accessing the OOB area from the mxc_nand
> > driver due to an Obiwan error in the mxc_nand_v[12]_ooblayout_free()
> > functions. They report a bogus oobregion { 64, 7 } which leads to
> > errors accessing bogus data when reading the oob area.
> > 
> > Prior to the commit the mtd-oobtest module could be run without any
> > errors. With the offending commit, this test fails with results like:
> > |Running mtd-oobtest
> > |
> > |=================================================
> > |mtd_oobtest: MTD device: 5
> > |mtd_oobtest: MTD device size 524288, eraseblock size 131072, page size 2048, count of eraseblocks 4, pages per eraseblock 64, OOB size 64
> > |mtd_test: scanning for bad eraseblocks
> > |mtd_test: scanned 4 eraseblocks, 0 are bad
> > |mtd_oobtest: test 1 of 5
> > |mtd_oobtest: writing OOBs of whole device
> > |mtd_oobtest: written up to eraseblock 0
> > |mtd_oobtest: written 4 eraseblocks
> > |mtd_oobtest: verifying all eraseblocks
> > |mtd_oobtest: error @addr[0x0:0x19] 0x9a -> 0x78 diff 0xe2
> > |mtd_oobtest: error @addr[0x0:0x1a] 0xcc -> 0x0 diff 0xcc
> > |mtd_oobtest: error @addr[0x0:0x1b] 0xe0 -> 0x85 diff 0x65
> > |mtd_oobtest: error @addr[0x0:0x1c] 0x60 -> 0x62 diff 0x2
> > |mtd_oobtest: error @addr[0x0:0x1d] 0x69 -> 0x45 diff 0x2c
> > |mtd_oobtest: error @addr[0x0:0x1e] 0xcd -> 0xa0 diff 0x6d
> > |mtd_oobtest: error @addr[0x0:0x1f] 0xf2 -> 0x60 diff 0x92
> > |mtd_oobtest: error: verify failed at 0x0
> > [...]
> > 
> > Signed-off-by: Lothar Waßmann <LW@KARO-electronics.de>
> > ---
> >  drivers/mtd/nand/mxc_nand.c | 4 ++--
> >  1 file changed, 2 insertions(+), 2 deletions(-)
> > 
> > diff --git a/drivers/mtd/nand/mxc_nand.c b/drivers/mtd/nand/mxc_nand.c
> > index 5173fad..fdee907 100644
> > --- a/drivers/mtd/nand/mxc_nand.c
> > +++ b/drivers/mtd/nand/mxc_nand.c
> > @@ -893,7 +893,7 @@ static int mxc_v1_ooblayout_free(struct mtd_info *mtd, int section,
> >  {
> >  	struct nand_chip *nand_chip = mtd_to_nand(mtd);
> >  
> > -	if (section > nand_chip->ecc.steps)
> > +	if (section >= nand_chip->ecc.steps)
> >  		return -ERANGE;
> 
> Hm, looking at the commit you're pointing to, it seems that this test
> is correct (we have X + 1 free sections, where X is the number of ECC
> steps).
> 
You are right. I didn't verify the v1 case (for which I have no HW here
any more).
I'll send a corrected patch.


Lothar Waßmann

[toc] | [prev] | [next] | [standalone]

#1486297 — Re: [PATCH BUGFIX] mtd: nand: mxc: fix obiwan error in mxc_nand_v[12]_ooblayout_free() functions

On Fri, 16 Sep 2016 10:09:25 +0200
Lothar Waßmann <LW@KARO-electronics.de> wrote:

> Hi,
> 
> On Thu, 15 Sep 2016 18:06:05 +0200 Boris Brezillon wrote:
> > Hi Lothar,
> > 
> > On Fri,  9 Sep 2016 16:44:11 +0200
> > Lothar Waßmann <LW@KARO-electronics.de> wrote:
> >   
> > > commit a894cf6c5a82 ("mtd: nand: mxc: switch to mtd_ooblayout_ops")
> > > introduced a regression accessing the OOB area from the mxc_nand
> > > driver due to an Obiwan error in the mxc_nand_v[12]_ooblayout_free()
> > > functions. They report a bogus oobregion { 64, 7 } which leads to
> > > errors accessing bogus data when reading the oob area.
> > > 
> > > Prior to the commit the mtd-oobtest module could be run without any
> > > errors. With the offending commit, this test fails with results like:
> > > |Running mtd-oobtest
> > > |
> > > |=================================================
> > > |mtd_oobtest: MTD device: 5
> > > |mtd_oobtest: MTD device size 524288, eraseblock size 131072, page size 2048, count of eraseblocks 4, pages per eraseblock 64, OOB size 64
> > > |mtd_test: scanning for bad eraseblocks
> > > |mtd_test: scanned 4 eraseblocks, 0 are bad
> > > |mtd_oobtest: test 1 of 5
> > > |mtd_oobtest: writing OOBs of whole device
> > > |mtd_oobtest: written up to eraseblock 0
> > > |mtd_oobtest: written 4 eraseblocks
> > > |mtd_oobtest: verifying all eraseblocks
> > > |mtd_oobtest: error @addr[0x0:0x19] 0x9a -> 0x78 diff 0xe2
> > > |mtd_oobtest: error @addr[0x0:0x1a] 0xcc -> 0x0 diff 0xcc
> > > |mtd_oobtest: error @addr[0x0:0x1b] 0xe0 -> 0x85 diff 0x65
> > > |mtd_oobtest: error @addr[0x0:0x1c] 0x60 -> 0x62 diff 0x2
> > > |mtd_oobtest: error @addr[0x0:0x1d] 0x69 -> 0x45 diff 0x2c
> > > |mtd_oobtest: error @addr[0x0:0x1e] 0xcd -> 0xa0 diff 0x6d
> > > |mtd_oobtest: error @addr[0x0:0x1f] 0xf2 -> 0x60 diff 0x92
> > > |mtd_oobtest: error: verify failed at 0x0
> > > [...]
> > > 
> > > Signed-off-by: Lothar Waßmann <LW@KARO-electronics.de>
> > > ---
> > >  drivers/mtd/nand/mxc_nand.c | 4 ++--
> > >  1 file changed, 2 insertions(+), 2 deletions(-)
> > > 
> > > diff --git a/drivers/mtd/nand/mxc_nand.c b/drivers/mtd/nand/mxc_nand.c
> > > index 5173fad..fdee907 100644
> > > --- a/drivers/mtd/nand/mxc_nand.c
> > > +++ b/drivers/mtd/nand/mxc_nand.c
> > > @@ -893,7 +893,7 @@ static int mxc_v1_ooblayout_free(struct mtd_info *mtd, int section,
> > >  {
> > >  	struct nand_chip *nand_chip = mtd_to_nand(mtd);
> > >  
> > > -	if (section > nand_chip->ecc.steps)
> > > +	if (section >= nand_chip->ecc.steps)
> > >  		return -ERANGE;  
> > 
> > Hm, looking at the commit you're pointing to, it seems that this test
> > is correct (we have X + 1 free sections, where X is the number of ECC
> > steps).
> >   
> You are right. I didn't verify the v1 case (for which I have no HW here
> any more).
> I'll send a corrected patch.

No need to resend, I fixed it locally.

Thanks,

Boris

[toc] | [prev] | [standalone]

Back to top | Article view | linux.kernel

csiph-web