diff mbox series

mtd: rawnand: qcom: fix memory corruption that causes panic

Message ID 1649914773-22434-1-git-send-email-quic_mdalam@quicinc.com (mailing list archive)
State Superseded
Headers show
Series mtd: rawnand: qcom: fix memory corruption that causes panic | expand

Commit Message

Md Sadre Alam April 14, 2022, 5:39 a.m. UTC
This patch fixes a memory corruption that occurred in the
nand_scan() path for Hynix nand device.

On boot, for Hynix nand device will panic at a weird place:
| Unable to handle kernel NULL pointer dereference at virtual
  address 00000070
| [00000070] *pgd=00000000
| Internal error: Oops: 5 [#1] PREEMPT SMP ARM
| Modules linked in:
| CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.17.0-01473-g13ae1769cfb0
  #38
| Hardware name: Generic DT based system
| PC is at nandc_set_reg+0x8/0x1c
| LR is at qcom_nandc_command+0x20c/0x5d0
| pc : [<c088b74c>]    lr : [<c088d9c8>]    psr: 00000113
| sp : c14adc50  ip : c14ee208  fp : c0cc970c
| r10: 000000a3  r9 : 00000000  r8 : 00000040
| r7 : c16f6a00  r6 : 00000090  r5 : 00000004  r4 :c14ee040
| r3 : 00000000  r2 : 0000000b  r1 : 00000000  r0 :c14ee040
| Flags: nzcv  IRQs on  FIQs on  Mode SVC_32  ISA ARM Segment none
| Control: 10c5387d  Table: 8020406a  DAC: 00000051
| Register r0 information: slab kmalloc-2k start c14ee000 pointer offset
  64 size 2048
| Process swapper/0 (pid: 1, stack limit = 0x(ptrval))
| nandc_set_reg from qcom_nandc_command+0x20c/0x5d0
| qcom_nandc_command from nand_readid_op+0x198/0x1e8
| nand_readid_op from hynix_nand_has_valid_jedecid+0x30/0x78
| hynix_nand_has_valid_jedecid from hynix_nand_init+0xb8/0x454
| hynix_nand_init from nand_scan_with_ids+0xa30/0x14a8
| nand_scan_with_ids from qcom_nandc_probe+0x648/0x7b0
| qcom_nandc_probe from platform_probe+0x58/0xac

The problem is that the nand_scan()'s qcom_nand_attach_chip callback
is updating the nandc->max_cwperpage from 1 to 4.This causes the
sg_init_table of clear_bam_transaction() in the driver's
qcom_nandc_command() to memset much more than what was initially
allocated by alloc_bam_transaction().

This patch will update nandc->max_cwperpage 1 to 4 after nand_scan()
returns, and remove updating nandc->max_cwperpage from
qcom_nand_attach_chip call back.

Signed-off-by: Md Sadre Alam <quic_mdalam@quicinc.com>
Signed-off-by: Sricharan R <quic_srichara@quicinc.com>
---
 drivers/mtd/nand/raw/qcom_nandc.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

Comments

Miquel Raynal April 14, 2022, 8:15 a.m. UTC | #1
Hi Md,

quic_mdalam@quicinc.com wrote on Thu, 14 Apr 2022 11:09:33 +0530:

> This patch fixes a memory corruption that occurred in the
> nand_scan() path for Hynix nand device.
> 
> On boot, for Hynix nand device will panic at a weird place:
> | Unable to handle kernel NULL pointer dereference at virtual
>   address 00000070
> | [00000070] *pgd=00000000
> | Internal error: Oops: 5 [#1] PREEMPT SMP ARM
> | Modules linked in:
> | CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.17.0-01473-g13ae1769cfb0
>   #38
> | Hardware name: Generic DT based system
> | PC is at nandc_set_reg+0x8/0x1c
> | LR is at qcom_nandc_command+0x20c/0x5d0
> | pc : [<c088b74c>]    lr : [<c088d9c8>]    psr: 00000113
> | sp : c14adc50  ip : c14ee208  fp : c0cc970c
> | r10: 000000a3  r9 : 00000000  r8 : 00000040
> | r7 : c16f6a00  r6 : 00000090  r5 : 00000004  r4 :c14ee040
> | r3 : 00000000  r2 : 0000000b  r1 : 00000000  r0 :c14ee040
> | Flags: nzcv  IRQs on  FIQs on  Mode SVC_32  ISA ARM Segment none
> | Control: 10c5387d  Table: 8020406a  DAC: 00000051
> | Register r0 information: slab kmalloc-2k start c14ee000 pointer offset
>   64 size 2048
> | Process swapper/0 (pid: 1, stack limit = 0x(ptrval))
> | nandc_set_reg from qcom_nandc_command+0x20c/0x5d0
> | qcom_nandc_command from nand_readid_op+0x198/0x1e8
> | nand_readid_op from hynix_nand_has_valid_jedecid+0x30/0x78
> | hynix_nand_has_valid_jedecid from hynix_nand_init+0xb8/0x454
> | hynix_nand_init from nand_scan_with_ids+0xa30/0x14a8
> | nand_scan_with_ids from qcom_nandc_probe+0x648/0x7b0
> | qcom_nandc_probe from platform_probe+0x58/0xac
> 
> The problem is that the nand_scan()'s qcom_nand_attach_chip callback
> is updating the nandc->max_cwperpage from 1 to 4.This causes the
> sg_init_table of clear_bam_transaction() in the driver's
> qcom_nandc_command() to memset much more than what was initially
> allocated by alloc_bam_transaction().

Thanks for investigating!

> This patch will update nandc->max_cwperpage 1 to 4 after nand_scan()
> returns, and remove updating nandc->max_cwperpage from
> qcom_nand_attach_chip call back.

The fix does not look right, as far as I understand, this should be
properly handled during the attach phase. That is where we have all
information about the chip and do the configuration for this chip.

If you update max_cwperpage there you should probably update other
internal variables that depend on it as well.

> Signed-off-by: Md Sadre Alam <quic_mdalam@quicinc.com>
> Signed-off-by: Sricharan R <quic_srichara@quicinc.com>
> ---
>  drivers/mtd/nand/raw/qcom_nandc.c | 8 ++++----
>  1 file changed, 4 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/mtd/nand/raw/qcom_nandc.c b/drivers/mtd/nand/raw/qcom_nandc.c
> index 1a77542..aa3ec45 100644
> --- a/drivers/mtd/nand/raw/qcom_nandc.c
> +++ b/drivers/mtd/nand/raw/qcom_nandc.c
> @@ -2652,9 +2652,6 @@ static int qcom_nand_attach_chip(struct nand_chip *chip)
>  
>  	mtd_set_ooblayout(mtd, &qcom_nand_ooblayout_ops);
>  
> -	nandc->max_cwperpage = max_t(unsigned int, nandc->max_cwperpage,
> -				     cwperpage);
> -
>  	/*
>  	 * DATA_UD_BYTES varies based on whether the read/write command protects
>  	 * spare data with ECC too. We protect spare data by default, so we set
> @@ -2909,7 +2906,7 @@ static int qcom_nand_host_init_and_register(struct qcom_nand_controller *nandc,
>  	struct nand_chip *chip = &host->chip;
>  	struct mtd_info *mtd = nand_to_mtd(chip);
>  	struct device *dev = nandc->dev;
> -	int ret;
> +	int ret, cwperpage;
>  
>  	ret = of_property_read_u32(dn, "reg", &host->cs);
>  	if (ret) {
> @@ -2955,6 +2952,9 @@ static int qcom_nand_host_init_and_register(struct qcom_nand_controller *nandc,
>  	if (ret)
>  		return ret;
>  
> +	cwperpage = mtd->writesize / NANDC_STEP_SIZE;
> +	nandc->max_cwperpage = max_t(unsigned int, nandc->max_cwperpage,
> +				     cwperpage);
>  	if (nandc->props->is_bam) {
>  		free_bam_transaction(nandc);
>  		nandc->bam_txn = alloc_bam_transaction(nandc);


Thanks,
Miquèl
Md Sadre Alam April 14, 2022, 12:20 p.m. UTC | #2
> Hi Md,
>
> quic_mdalam@quicinc.com wrote on Thu, 14 Apr 2022 11:09:33 +0530:
>
>> This patch fixes a memory corruption that occurred in the
>> nand_scan() path for Hynix nand device.
>>
>> On boot, for Hynix nand device will panic at a weird place:
>> | Unable to handle kernel NULL pointer dereference at virtual
>>    address 00000070
>> | [00000070] *pgd=00000000
>> | Internal error: Oops: 5 [#1] PREEMPT SMP ARM Modules linked in:
>> | CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.17.0-01473-g13ae1769cfb0
>>    #38
>> | Hardware name: Generic DT based system PC is at
>> | nandc_set_reg+0x8/0x1c LR is at qcom_nandc_command+0x20c/0x5d0
>> | pc : [<c088b74c>]    lr : [<c088d9c8>]    psr: 00000113
>> | sp : c14adc50  ip : c14ee208  fp : c0cc970c
>> | r10: 000000a3  r9 : 00000000  r8 : 00000040
>> | r7 : c16f6a00  r6 : 00000090  r5 : 00000004  r4 :c14ee040
>> | r3 : 00000000  r2 : 0000000b  r1 : 00000000  r0 :c14ee040
>> | Flags: nzcv  IRQs on  FIQs on  Mode SVC_32  ISA ARM Segment none
>> | Control: 10c5387d  Table: 8020406a  DAC: 00000051 Register r0
>> | information: slab kmalloc-2k start c14ee000 pointer offset
>>    64 size 2048
>> | Process swapper/0 (pid: 1, stack limit = 0x(ptrval)) nandc_set_reg
>> | from qcom_nandc_command+0x20c/0x5d0 qcom_nandc_command from
>> | nand_readid_op+0x198/0x1e8 nand_readid_op from
>> | hynix_nand_has_valid_jedecid+0x30/0x78
>> | hynix_nand_has_valid_jedecid from hynix_nand_init+0xb8/0x454
>> | hynix_nand_init from nand_scan_with_ids+0xa30/0x14a8
>> | nand_scan_with_ids from qcom_nandc_probe+0x648/0x7b0
>> | qcom_nandc_probe from platform_probe+0x58/0xac
>>
>> The problem is that the nand_scan()'s qcom_nand_attach_chip callback
>> is updating the nandc->max_cwperpage from 1 to 4.This causes the
>> sg_init_table of clear_bam_transaction() in the driver's
>> qcom_nandc_command() to memset much more than what was initially
>> allocated by alloc_bam_transaction().
> Thanks for investigating!
>
>> This patch will update nandc->max_cwperpage 1 to 4 after nand_scan()
>> returns, and remove updating nandc->max_cwperpage from
>> qcom_nand_attach_chip call back.
> The fix does not look right, as far as I understand, this should be properly handled during the attach phase. That is where we have all information about the chip and do the configuration for this chip.
>
> If you update max_cwperpage there you should probably update other internal variables that depend on it as well.

    Currently we are updating max_cwperpage  in qcom_nand_attach_chip(), 
but we are seeing issue for Hynix nand device since nand_scan_tail() is 
getting called after nand_attach() and in nand_attach() we are updating 
max_cwperpage to 4 or 8 based on page size.

     From nand_scan_tail() there is a call for nand_manufacturer_init() 
, specific to Hynix nand read_id is getting called that's why we are 
seeing this issue only for Hynix nand device. Read id sequence as below

    hynix_nand_has_valid_jedecid()

                 |

    nand_readid_op()

              |

  qcom_nandc_command()

             |

pre_command()

           |

clear_bam_transaction()   --> In this call we are doing sg_init_table() 
which is calling memset() based on max_cwperpage.Since initially we have 
allocated bam transaction as per max_cwperpage =1 and , since 
nand_chip_attach() updated max_cwperpage,  now we are doing memset as 
per max_cwperpage = 4 or 8.


So anyway we have to updated max_cwperpage after nand_scan() call only.  
Since there is no other dependency on max_cwperpage in 
nand_attach_chip() and we are using this in bam_alloc() and bam_clear().

>
>> Signed-off-by: Md Sadre Alam <quic_mdalam@quicinc.com>
>> Signed-off-by: Sricharan R <quic_srichara@quicinc.com>
>> ---
>>   drivers/mtd/nand/raw/qcom_nandc.c | 8 ++++----
>>   1 file changed, 4 insertions(+), 4 deletions(-)
>>
>> diff --git a/drivers/mtd/nand/raw/qcom_nandc.c
>> b/drivers/mtd/nand/raw/qcom_nandc.c
>> index 1a77542..aa3ec45 100644
>> --- a/drivers/mtd/nand/raw/qcom_nandc.c
>> +++ b/drivers/mtd/nand/raw/qcom_nandc.c
>> @@ -2652,9 +2652,6 @@ static int qcom_nand_attach_chip(struct
>> nand_chip *chip)
>>
>>        mtd_set_ooblayout(mtd, &qcom_nand_ooblayout_ops);
>>
>> -     nandc->max_cwperpage = max_t(unsigned int, nandc->max_cwperpage,
>> -                                  cwperpage);
>> -
>>        /*
>>         * DATA_UD_BYTES varies based on whether the read/write command protects
>>         * spare data with ECC too. We protect spare data by default, so
>> we set @@ -2909,7 +2906,7 @@ static int qcom_nand_host_init_and_register(struct qcom_nand_controller *nandc,
>>        struct nand_chip *chip = &host->chip;
>>        struct mtd_info *mtd = nand_to_mtd(chip);
>>        struct device *dev = nandc->dev;
>> -     int ret;
>> +     int ret, cwperpage;
>>
>>        ret = of_property_read_u32(dn, "reg", &host->cs);
>>        if (ret) {
>> @@ -2955,6 +2952,9 @@ static int qcom_nand_host_init_and_register(struct qcom_nand_controller *nandc,
>>        if (ret)
>>                return ret;
>>
>> +     cwperpage = mtd->writesize / NANDC_STEP_SIZE;
>> +     nandc->max_cwperpage = max_t(unsigned int, nandc->max_cwperpage,
>> +                                  cwperpage);
>>        if (nandc->props->is_bam) {
>>                free_bam_transaction(nandc);
>>                nandc->bam_txn = alloc_bam_transaction(nandc);
>
> Thanks,
> Miquèl
Miquel Raynal April 14, 2022, 12:42 p.m. UTC | #3
Hi Md,

quic_mdalam@quicinc.com wrote on Thu, 14 Apr 2022 17:50:48 +0530:

> > Hi Md,
> >
> > quic_mdalam@quicinc.com wrote on Thu, 14 Apr 2022 11:09:33 +0530:
> >  
> >> This patch fixes a memory corruption that occurred in the
> >> nand_scan() path for Hynix nand device.
> >>
> >> On boot, for Hynix nand device will panic at a weird place:
> >> | Unable to handle kernel NULL pointer dereference at virtual
> >>    address 00000070
> >> | [00000070] *pgd=00000000
> >> | Internal error: Oops: 5 [#1] PREEMPT SMP ARM Modules linked in:
> >> | CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.17.0-01473-g13ae1769cfb0
> >>    #38
> >> | Hardware name: Generic DT based system PC is at
> >> | nandc_set_reg+0x8/0x1c LR is at qcom_nandc_command+0x20c/0x5d0
> >> | pc : [<c088b74c>]    lr : [<c088d9c8>]    psr: 00000113
> >> | sp : c14adc50  ip : c14ee208  fp : c0cc970c
> >> | r10: 000000a3  r9 : 00000000  r8 : 00000040
> >> | r7 : c16f6a00  r6 : 00000090  r5 : 00000004  r4 :c14ee040
> >> | r3 : 00000000  r2 : 0000000b  r1 : 00000000  r0 :c14ee040
> >> | Flags: nzcv  IRQs on  FIQs on  Mode SVC_32  ISA ARM Segment none
> >> | Control: 10c5387d  Table: 8020406a  DAC: 00000051 Register r0
> >> | information: slab kmalloc-2k start c14ee000 pointer offset
> >>    64 size 2048
> >> | Process swapper/0 (pid: 1, stack limit = 0x(ptrval)) nandc_set_reg
> >> | from qcom_nandc_command+0x20c/0x5d0 qcom_nandc_command from
> >> | nand_readid_op+0x198/0x1e8 nand_readid_op from
> >> | hynix_nand_has_valid_jedecid+0x30/0x78
> >> | hynix_nand_has_valid_jedecid from hynix_nand_init+0xb8/0x454
> >> | hynix_nand_init from nand_scan_with_ids+0xa30/0x14a8
> >> | nand_scan_with_ids from qcom_nandc_probe+0x648/0x7b0
> >> | qcom_nandc_probe from platform_probe+0x58/0xac
> >>
> >> The problem is that the nand_scan()'s qcom_nand_attach_chip callback
> >> is updating the nandc->max_cwperpage from 1 to 4.This causes the
> >> sg_init_table of clear_bam_transaction() in the driver's
> >> qcom_nandc_command() to memset much more than what was initially
> >> allocated by alloc_bam_transaction().  
> > Thanks for investigating!
> >  
> >> This patch will update nandc->max_cwperpage 1 to 4 after nand_scan()
> >> returns, and remove updating nandc->max_cwperpage from
> >> qcom_nand_attach_chip call back.  
> > The fix does not look right, as far as I understand, this should be properly handled during the attach phase. That is where we have all information about the chip and do the configuration for this chip.
> >
> > If you update max_cwperpage there you should probably update other internal variables that depend on it as well.  
> 
>     Currently we are updating max_cwperpage  in qcom_nand_attach_chip(), but we are seeing issue for Hynix nand device since nand_scan_tail() is getting called after nand_attach() and in nand_attach() we are updating max_cwperpage to 4 or 8 based on page size.
> 
>      From nand_scan_tail() there is a call for nand_manufacturer_init() , specific to Hynix nand read_id is getting called that's why we are seeing this issue only for Hynix nand device. Read id sequence as below
> 
>     hynix_nand_has_valid_jedecid()
> 
>                  |
> 
>     nand_readid_op()
> 
>               |
> 
>   qcom_nandc_command()
> 
>              |
> 
> pre_command()
> 
>            |
> 
> clear_bam_transaction()   --> In this call we are doing sg_init_table() which is calling memset() based on max_cwperpage.Since initially we have allocated bam transaction as per max_cwperpage =1 and , since nand_chip_attach() updated max_cwperpage,  now we are doing memset as per max_cwperpage = 4 or 8.
> 
> 
> So anyway we have to updated max_cwperpage after nand_scan() call only.  Since there is no other dependency on max_cwperpage in nand_attach_chip() and we are using this in bam_alloc() and bam_clear().

Why don't you update the sg table after increasing max_cwperpage?

> 
> >  
> >> Signed-off-by: Md Sadre Alam <quic_mdalam@quicinc.com>
> >> Signed-off-by: Sricharan R <quic_srichara@quicinc.com>
> >> ---
> >>   drivers/mtd/nand/raw/qcom_nandc.c | 8 ++++----
> >>   1 file changed, 4 insertions(+), 4 deletions(-)
> >>
> >> diff --git a/drivers/mtd/nand/raw/qcom_nandc.c
> >> b/drivers/mtd/nand/raw/qcom_nandc.c
> >> index 1a77542..aa3ec45 100644
> >> --- a/drivers/mtd/nand/raw/qcom_nandc.c
> >> +++ b/drivers/mtd/nand/raw/qcom_nandc.c
> >> @@ -2652,9 +2652,6 @@ static int qcom_nand_attach_chip(struct
> >> nand_chip *chip)
> >>
> >>        mtd_set_ooblayout(mtd, &qcom_nand_ooblayout_ops);
> >>
> >> -     nandc->max_cwperpage = max_t(unsigned int, nandc->max_cwperpage,
> >> -                                  cwperpage);
> >> -
> >>        /*
> >>         * DATA_UD_BYTES varies based on whether the read/write command protects
> >>         * spare data with ECC too. We protect spare data by default, so
> >> we set @@ -2909,7 +2906,7 @@ static int qcom_nand_host_init_and_register(struct qcom_nand_controller *nandc,
> >>        struct nand_chip *chip = &host->chip;
> >>        struct mtd_info *mtd = nand_to_mtd(chip);
> >>        struct device *dev = nandc->dev;
> >> -     int ret;
> >> +     int ret, cwperpage;
> >>
> >>        ret = of_property_read_u32(dn, "reg", &host->cs);
> >>        if (ret) {
> >> @@ -2955,6 +2952,9 @@ static int qcom_nand_host_init_and_register(struct qcom_nand_controller *nandc,
> >>        if (ret)
> >>                return ret;
> >>
> >> +     cwperpage = mtd->writesize / NANDC_STEP_SIZE;
> >> +     nandc->max_cwperpage = max_t(unsigned int, nandc->max_cwperpage,
> >> +                                  cwperpage);
> >>        if (nandc->props->is_bam) {
> >>                free_bam_transaction(nandc);
> >>                nandc->bam_txn = alloc_bam_transaction(nandc);  
> >
> > Thanks,
> > Miquèl  


Thanks,
Miquèl
Manivannan Sadhasivam April 14, 2022, 2:39 p.m. UTC | #4
On Thu, Apr 14, 2022 at 02:42:36PM +0200, Miquel Raynal wrote:
> Hi Md,
> 
> quic_mdalam@quicinc.com wrote on Thu, 14 Apr 2022 17:50:48 +0530:
> 
> > > Hi Md,
> > >
> > > quic_mdalam@quicinc.com wrote on Thu, 14 Apr 2022 11:09:33 +0530:
> > >  
> > >> This patch fixes a memory corruption that occurred in the
> > >> nand_scan() path for Hynix nand device.
> > >>
> > >> On boot, for Hynix nand device will panic at a weird place:
> > >> | Unable to handle kernel NULL pointer dereference at virtual
> > >>    address 00000070
> > >> | [00000070] *pgd=00000000
> > >> | Internal error: Oops: 5 [#1] PREEMPT SMP ARM Modules linked in:
> > >> | CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.17.0-01473-g13ae1769cfb0
> > >>    #38
> > >> | Hardware name: Generic DT based system PC is at
> > >> | nandc_set_reg+0x8/0x1c LR is at qcom_nandc_command+0x20c/0x5d0
> > >> | pc : [<c088b74c>]    lr : [<c088d9c8>]    psr: 00000113
> > >> | sp : c14adc50  ip : c14ee208  fp : c0cc970c
> > >> | r10: 000000a3  r9 : 00000000  r8 : 00000040
> > >> | r7 : c16f6a00  r6 : 00000090  r5 : 00000004  r4 :c14ee040
> > >> | r3 : 00000000  r2 : 0000000b  r1 : 00000000  r0 :c14ee040
> > >> | Flags: nzcv  IRQs on  FIQs on  Mode SVC_32  ISA ARM Segment none
> > >> | Control: 10c5387d  Table: 8020406a  DAC: 00000051 Register r0
> > >> | information: slab kmalloc-2k start c14ee000 pointer offset
> > >>    64 size 2048
> > >> | Process swapper/0 (pid: 1, stack limit = 0x(ptrval)) nandc_set_reg
> > >> | from qcom_nandc_command+0x20c/0x5d0 qcom_nandc_command from
> > >> | nand_readid_op+0x198/0x1e8 nand_readid_op from
> > >> | hynix_nand_has_valid_jedecid+0x30/0x78
> > >> | hynix_nand_has_valid_jedecid from hynix_nand_init+0xb8/0x454
> > >> | hynix_nand_init from nand_scan_with_ids+0xa30/0x14a8
> > >> | nand_scan_with_ids from qcom_nandc_probe+0x648/0x7b0
> > >> | qcom_nandc_probe from platform_probe+0x58/0xac
> > >>
> > >> The problem is that the nand_scan()'s qcom_nand_attach_chip callback
> > >> is updating the nandc->max_cwperpage from 1 to 4.This causes the
> > >> sg_init_table of clear_bam_transaction() in the driver's
> > >> qcom_nandc_command() to memset much more than what was initially
> > >> allocated by alloc_bam_transaction().  
> > > Thanks for investigating!
> > >  
> > >> This patch will update nandc->max_cwperpage 1 to 4 after nand_scan()
> > >> returns, and remove updating nandc->max_cwperpage from
> > >> qcom_nand_attach_chip call back.  
> > > The fix does not look right, as far as I understand, this should be properly handled during the attach phase. That is where we have all information about the chip and do the configuration for this chip.
> > >
> > > If you update max_cwperpage there you should probably update other internal variables that depend on it as well.  
> > 
> >     Currently we are updating max_cwperpage  in qcom_nand_attach_chip(), but we are seeing issue for Hynix nand device since nand_scan_tail() is getting called after nand_attach() and in nand_attach() we are updating max_cwperpage to 4 or 8 based on page size.
> > 
> >      From nand_scan_tail() there is a call for nand_manufacturer_init() , specific to Hynix nand read_id is getting called that's why we are seeing this issue only for Hynix nand device. Read id sequence as below
> > 
> >     hynix_nand_has_valid_jedecid()
> > 
> >                  |
> > 
> >     nand_readid_op()
> > 
> >               |
> > 
> >   qcom_nandc_command()
> > 
> >              |
> > 
> > pre_command()
> > 
> >            |
> > 
> > clear_bam_transaction()   --> In this call we are doing sg_init_table() which is calling memset() based on max_cwperpage.Since initially we have allocated bam transaction as per max_cwperpage =1 and , since nand_chip_attach() updated max_cwperpage,  now we are doing memset as per max_cwperpage = 4 or 8.
> > 
> > 
> > So anyway we have to updated max_cwperpage after nand_scan() call only.  Since there is no other dependency on max_cwperpage in nand_attach_chip() and we are using this in bam_alloc() and bam_clear().
> 
> Why don't you update the sg table after increasing max_cwperpage?
> 

Or we could move the bam reallocation inside qcom_nand_attach_chip() as below?

diff --git a/drivers/mtd/nand/raw/qcom_nandc.c b/drivers/mtd/nand/raw/qcom_nandc.c
index 7c6efa3b6255..58c16054630f 100644
--- a/drivers/mtd/nand/raw/qcom_nandc.c
+++ b/drivers/mtd/nand/raw/qcom_nandc.c
@@ -2653,9 +2653,23 @@ static int qcom_nand_attach_chip(struct nand_chip *chip)
 
        mtd_set_ooblayout(mtd, &qcom_nand_ooblayout_ops);
 
+       /* Free the initially allocated BAM transaction for reading the ONFI params */
+       if (nandc->props->is_bam)
+               free_bam_transaction(nandc);
+
        nandc->max_cwperpage = max_t(unsigned int, nandc->max_cwperpage,
                                     cwperpage);
 
+       /* Now allocate the BAM transaction based on updated max_cwperpage */
+       if (nandc->props->is_bam) {
+               nandc->bam_txn = alloc_bam_transaction(nandc);
+               if (!nandc->bam_txn) {
+                       dev_err(nandc->dev,
+                               "failed to allocate bam transaction\n");
+                       return -ENOMEM;
+               }
+       }
+
        /*
         * DATA_UD_BYTES varies based on whether the read/write command protects
         * spare data with ECC too. We protect spare data by default, so we set
@@ -2956,17 +2970,6 @@ static int qcom_nand_host_init_and_register(struct qcom_nand_controller *nandc,
        if (ret)
                return ret;
 
-       if (nandc->props->is_bam) {
-               free_bam_transaction(nandc);
-               nandc->bam_txn = alloc_bam_transaction(nandc);
-               if (!nandc->bam_txn) {
-                       dev_err(nandc->dev,
-                               "failed to allocate bam transaction\n");
-                       nand_cleanup(chip);
-                       return -ENOMEM;
-               }
-       }
-
        ret = mtd_device_parse_register(mtd, probes, NULL, NULL, 0);
        if (ret)
                nand_cleanup(chip);

Thanks,
Mani
Miquel Raynal April 14, 2022, 2:59 p.m. UTC | #5
Hi Manivannan,

mani@kernel.org wrote on Thu, 14 Apr 2022 20:09:07 +0530:

> On Thu, Apr 14, 2022 at 02:42:36PM +0200, Miquel Raynal wrote:
> > Hi Md,
> > 
> > quic_mdalam@quicinc.com wrote on Thu, 14 Apr 2022 17:50:48 +0530:
> >   
> > > > Hi Md,
> > > >
> > > > quic_mdalam@quicinc.com wrote on Thu, 14 Apr 2022 11:09:33 +0530:
> > > >    
> > > >> This patch fixes a memory corruption that occurred in the
> > > >> nand_scan() path for Hynix nand device.
> > > >>
> > > >> On boot, for Hynix nand device will panic at a weird place:
> > > >> | Unable to handle kernel NULL pointer dereference at virtual
> > > >>    address 00000070
> > > >> | [00000070] *pgd=00000000
> > > >> | Internal error: Oops: 5 [#1] PREEMPT SMP ARM Modules linked in:
> > > >> | CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.17.0-01473-g13ae1769cfb0
> > > >>    #38
> > > >> | Hardware name: Generic DT based system PC is at
> > > >> | nandc_set_reg+0x8/0x1c LR is at qcom_nandc_command+0x20c/0x5d0
> > > >> | pc : [<c088b74c>]    lr : [<c088d9c8>]    psr: 00000113
> > > >> | sp : c14adc50  ip : c14ee208  fp : c0cc970c
> > > >> | r10: 000000a3  r9 : 00000000  r8 : 00000040
> > > >> | r7 : c16f6a00  r6 : 00000090  r5 : 00000004  r4 :c14ee040
> > > >> | r3 : 00000000  r2 : 0000000b  r1 : 00000000  r0 :c14ee040
> > > >> | Flags: nzcv  IRQs on  FIQs on  Mode SVC_32  ISA ARM Segment none
> > > >> | Control: 10c5387d  Table: 8020406a  DAC: 00000051 Register r0
> > > >> | information: slab kmalloc-2k start c14ee000 pointer offset
> > > >>    64 size 2048
> > > >> | Process swapper/0 (pid: 1, stack limit = 0x(ptrval)) nandc_set_reg
> > > >> | from qcom_nandc_command+0x20c/0x5d0 qcom_nandc_command from
> > > >> | nand_readid_op+0x198/0x1e8 nand_readid_op from
> > > >> | hynix_nand_has_valid_jedecid+0x30/0x78
> > > >> | hynix_nand_has_valid_jedecid from hynix_nand_init+0xb8/0x454
> > > >> | hynix_nand_init from nand_scan_with_ids+0xa30/0x14a8
> > > >> | nand_scan_with_ids from qcom_nandc_probe+0x648/0x7b0
> > > >> | qcom_nandc_probe from platform_probe+0x58/0xac
> > > >>
> > > >> The problem is that the nand_scan()'s qcom_nand_attach_chip callback
> > > >> is updating the nandc->max_cwperpage from 1 to 4.This causes the
> > > >> sg_init_table of clear_bam_transaction() in the driver's
> > > >> qcom_nandc_command() to memset much more than what was initially
> > > >> allocated by alloc_bam_transaction().    
> > > > Thanks for investigating!
> > > >    
> > > >> This patch will update nandc->max_cwperpage 1 to 4 after nand_scan()
> > > >> returns, and remove updating nandc->max_cwperpage from
> > > >> qcom_nand_attach_chip call back.    
> > > > The fix does not look right, as far as I understand, this should be properly handled during the attach phase. That is where we have all information about the chip and do the configuration for this chip.
> > > >
> > > > If you update max_cwperpage there you should probably update other internal variables that depend on it as well.    
> > > 
> > >     Currently we are updating max_cwperpage  in qcom_nand_attach_chip(), but we are seeing issue for Hynix nand device since nand_scan_tail() is getting called after nand_attach() and in nand_attach() we are updating max_cwperpage to 4 or 8 based on page size.
> > > 
> > >      From nand_scan_tail() there is a call for nand_manufacturer_init() , specific to Hynix nand read_id is getting called that's why we are seeing this issue only for Hynix nand device. Read id sequence as below
> > > 
> > >     hynix_nand_has_valid_jedecid()
> > > 
> > >                  |
> > > 
> > >     nand_readid_op()
> > > 
> > >               |
> > > 
> > >   qcom_nandc_command()
> > > 
> > >              |
> > > 
> > > pre_command()
> > > 
> > >            |
> > > 
> > > clear_bam_transaction()   --> In this call we are doing sg_init_table() which is calling memset() based on max_cwperpage.Since initially we have allocated bam transaction as per max_cwperpage =1 and , since nand_chip_attach() updated max_cwperpage,  now we are doing memset as per max_cwperpage = 4 or 8.
> > > 
> > > 
> > > So anyway we have to updated max_cwperpage after nand_scan() call only.  Since there is no other dependency on max_cwperpage in nand_attach_chip() and we are using this in bam_alloc() and bam_clear().  
> > 
> > Why don't you update the sg table after increasing max_cwperpage?
> >   
> 
> Or we could move the bam reallocation inside qcom_nand_attach_chip() as below?

Much better approach, yes.

> 
> diff --git a/drivers/mtd/nand/raw/qcom_nandc.c b/drivers/mtd/nand/raw/qcom_nandc.c
> index 7c6efa3b6255..58c16054630f 100644
> --- a/drivers/mtd/nand/raw/qcom_nandc.c
> +++ b/drivers/mtd/nand/raw/qcom_nandc.c
> @@ -2653,9 +2653,23 @@ static int qcom_nand_attach_chip(struct nand_chip *chip)
>  
>         mtd_set_ooblayout(mtd, &qcom_nand_ooblayout_ops);
>  
> +       /* Free the initially allocated BAM transaction for reading the ONFI params */
> +       if (nandc->props->is_bam)
> +               free_bam_transaction(nandc);
> +
>         nandc->max_cwperpage = max_t(unsigned int, nandc->max_cwperpage,
>                                      cwperpage);
>  
> +       /* Now allocate the BAM transaction based on updated max_cwperpage */
> +       if (nandc->props->is_bam) {
> +               nandc->bam_txn = alloc_bam_transaction(nandc);
> +               if (!nandc->bam_txn) {
> +                       dev_err(nandc->dev,
> +                               "failed to allocate bam transaction\n");
> +                       return -ENOMEM;
> +               }
> +       }
> +
>         /*
>          * DATA_UD_BYTES varies based on whether the read/write command protects
>          * spare data with ECC too. We protect spare data by default, so we set
> @@ -2956,17 +2970,6 @@ static int qcom_nand_host_init_and_register(struct qcom_nand_controller *nandc,
>         if (ret)
>                 return ret;
>  
> -       if (nandc->props->is_bam) {
> -               free_bam_transaction(nandc);
> -               nandc->bam_txn = alloc_bam_transaction(nandc);
> -               if (!nandc->bam_txn) {
> -                       dev_err(nandc->dev,
> -                               "failed to allocate bam transaction\n");
> -                       nand_cleanup(chip);
> -                       return -ENOMEM;
> -               }
> -       }
> -
>         ret = mtd_device_parse_register(mtd, probes, NULL, NULL, 0);
>         if (ret)
>                 nand_cleanup(chip);
> 
> Thanks,
> Mani


Thanks,
Miquèl
Md Sadre Alam April 14, 2022, 3:31 p.m. UTC | #6
On 4/14/2022 8:29 PM, Miquel Raynal wrote:
> WARNING: This email originated from outside of Qualcomm. Please be wary of any links or attachments, and do not enable macros.
>
> Hi Manivannan,
>
> mani@kernel.org wrote on Thu, 14 Apr 2022 20:09:07 +0530:
>
>> On Thu, Apr 14, 2022 at 02:42:36PM +0200, Miquel Raynal wrote:
>>> Hi Md,
>>>
>>> quic_mdalam@quicinc.com wrote on Thu, 14 Apr 2022 17:50:48 +0530:
>>>
>>>>> Hi Md,
>>>>>
>>>>> quic_mdalam@quicinc.com wrote on Thu, 14 Apr 2022 11:09:33 +0530:
>>>>>
>>>>>> This patch fixes a memory corruption that occurred in the
>>>>>> nand_scan() path for Hynix nand device.
>>>>>>
>>>>>> On boot, for Hynix nand device will panic at a weird place:
>>>>>> | Unable to handle kernel NULL pointer dereference at virtual
>>>>>>     address 00000070
>>>>>> | [00000070] *pgd=00000000
>>>>>> | Internal error: Oops: 5 [#1] PREEMPT SMP ARM Modules linked in:
>>>>>> | CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.17.0-01473-g13ae1769cfb0
>>>>>>     #38
>>>>>> | Hardware name: Generic DT based system PC is at
>>>>>> | nandc_set_reg+0x8/0x1c LR is at qcom_nandc_command+0x20c/0x5d0
>>>>>> | pc : [<c088b74c>]    lr : [<c088d9c8>]    psr: 00000113
>>>>>> | sp : c14adc50  ip : c14ee208  fp : c0cc970c
>>>>>> | r10: 000000a3  r9 : 00000000  r8 : 00000040
>>>>>> | r7 : c16f6a00  r6 : 00000090  r5 : 00000004  r4 :c14ee040
>>>>>> | r3 : 00000000  r2 : 0000000b  r1 : 00000000  r0 :c14ee040
>>>>>> | Flags: nzcv  IRQs on  FIQs on  Mode SVC_32  ISA ARM Segment none
>>>>>> | Control: 10c5387d  Table: 8020406a  DAC: 00000051 Register r0
>>>>>> | information: slab kmalloc-2k start c14ee000 pointer offset
>>>>>>     64 size 2048
>>>>>> | Process swapper/0 (pid: 1, stack limit = 0x(ptrval)) nandc_set_reg
>>>>>> | from qcom_nandc_command+0x20c/0x5d0 qcom_nandc_command from
>>>>>> | nand_readid_op+0x198/0x1e8 nand_readid_op from
>>>>>> | hynix_nand_has_valid_jedecid+0x30/0x78
>>>>>> | hynix_nand_has_valid_jedecid from hynix_nand_init+0xb8/0x454
>>>>>> | hynix_nand_init from nand_scan_with_ids+0xa30/0x14a8
>>>>>> | nand_scan_with_ids from qcom_nandc_probe+0x648/0x7b0
>>>>>> | qcom_nandc_probe from platform_probe+0x58/0xac
>>>>>>
>>>>>> The problem is that the nand_scan()'s qcom_nand_attach_chip callback
>>>>>> is updating the nandc->max_cwperpage from 1 to 4.This causes the
>>>>>> sg_init_table of clear_bam_transaction() in the driver's
>>>>>> qcom_nandc_command() to memset much more than what was initially
>>>>>> allocated by alloc_bam_transaction().
>>>>> Thanks for investigating!
>>>>>
>>>>>> This patch will update nandc->max_cwperpage 1 to 4 after nand_scan()
>>>>>> returns, and remove updating nandc->max_cwperpage from
>>>>>> qcom_nand_attach_chip call back.
>>>>> The fix does not look right, as far as I understand, this should be properly handled during the attach phase. That is where we have all information about the chip and do the configuration for this chip.
>>>>>
>>>>> If you update max_cwperpage there you should probably update other internal variables that depend on it as well.
>>>>      Currently we are updating max_cwperpage  in qcom_nand_attach_chip(), but we are seeing issue for Hynix nand device since nand_scan_tail() is getting called after nand_attach() and in nand_attach() we are updating max_cwperpage to 4 or 8 based on page size.
>>>>
>>>>       From nand_scan_tail() there is a call for nand_manufacturer_init() , specific to Hynix nand read_id is getting called that's why we are seeing this issue only for Hynix nand device. Read id sequence as below
>>>>
>>>>      hynix_nand_has_valid_jedecid()
>>>>
>>>>                   |
>>>>
>>>>      nand_readid_op()
>>>>
>>>>                |
>>>>
>>>>    qcom_nandc_command()
>>>>
>>>>               |
>>>>
>>>> pre_command()
>>>>
>>>>             |
>>>>
>>>> clear_bam_transaction()   --> In this call we are doing sg_init_table() which is calling memset() based on max_cwperpage.Since initially we have allocated bam transaction as per max_cwperpage =1 and , since nand_chip_attach() updated max_cwperpage,  now we are doing memset as per max_cwperpage = 4 or 8.
>>>>
>>>>
>>>> So anyway we have to updated max_cwperpage after nand_scan() call only.  Since there is no other dependency on max_cwperpage in nand_attach_chip() and we are using this in bam_alloc() and bam_clear().
>>> Why don't you update the sg table after increasing max_cwperpage?
>>>
>> Or we could move the bam reallocation inside qcom_nand_attach_chip() as below?
> Much better approach, yes.
  Updated in V2 patch , as Manivannan suggested.
>
>> diff --git a/drivers/mtd/nand/raw/qcom_nandc.c b/drivers/mtd/nand/raw/qcom_nandc.c
>> index 7c6efa3b6255..58c16054630f 100644
>> --- a/drivers/mtd/nand/raw/qcom_nandc.c
>> +++ b/drivers/mtd/nand/raw/qcom_nandc.c
>> @@ -2653,9 +2653,23 @@ static int qcom_nand_attach_chip(struct nand_chip *chip)
>>
>>          mtd_set_ooblayout(mtd, &qcom_nand_ooblayout_ops);
>>
>> +       /* Free the initially allocated BAM transaction for reading the ONFI params */
>> +       if (nandc->props->is_bam)
>> +               free_bam_transaction(nandc);
>> +
>>          nandc->max_cwperpage = max_t(unsigned int, nandc->max_cwperpage,
>>                                       cwperpage);
>>
>> +       /* Now allocate the BAM transaction based on updated max_cwperpage */
>> +       if (nandc->props->is_bam) {
>> +               nandc->bam_txn = alloc_bam_transaction(nandc);
>> +               if (!nandc->bam_txn) {
>> +                       dev_err(nandc->dev,
>> +                               "failed to allocate bam transaction\n");
>> +                       return -ENOMEM;
>> +               }
>> +       }
>> +
>>          /*
>>           * DATA_UD_BYTES varies based on whether the read/write command protects
>>           * spare data with ECC too. We protect spare data by default, so we set
>> @@ -2956,17 +2970,6 @@ static int qcom_nand_host_init_and_register(struct qcom_nand_controller *nandc,
>>          if (ret)
>>                  return ret;
>>
>> -       if (nandc->props->is_bam) {
>> -               free_bam_transaction(nandc);
>> -               nandc->bam_txn = alloc_bam_transaction(nandc);
>> -               if (!nandc->bam_txn) {
>> -                       dev_err(nandc->dev,
>> -                               "failed to allocate bam transaction\n");
>> -                       nand_cleanup(chip);
>> -                       return -ENOMEM;
>> -               }
>> -       }
>> -
>>          ret = mtd_device_parse_register(mtd, probes, NULL, NULL, 0);
>>          if (ret)
>>                  nand_cleanup(chip);
>>
>> Thanks,
>> Mani
>
> Thanks,
> Miquèl
diff mbox series

Patch

diff --git a/drivers/mtd/nand/raw/qcom_nandc.c b/drivers/mtd/nand/raw/qcom_nandc.c
index 1a77542..aa3ec45 100644
--- a/drivers/mtd/nand/raw/qcom_nandc.c
+++ b/drivers/mtd/nand/raw/qcom_nandc.c
@@ -2652,9 +2652,6 @@  static int qcom_nand_attach_chip(struct nand_chip *chip)
 
 	mtd_set_ooblayout(mtd, &qcom_nand_ooblayout_ops);
 
-	nandc->max_cwperpage = max_t(unsigned int, nandc->max_cwperpage,
-				     cwperpage);
-
 	/*
 	 * DATA_UD_BYTES varies based on whether the read/write command protects
 	 * spare data with ECC too. We protect spare data by default, so we set
@@ -2909,7 +2906,7 @@  static int qcom_nand_host_init_and_register(struct qcom_nand_controller *nandc,
 	struct nand_chip *chip = &host->chip;
 	struct mtd_info *mtd = nand_to_mtd(chip);
 	struct device *dev = nandc->dev;
-	int ret;
+	int ret, cwperpage;
 
 	ret = of_property_read_u32(dn, "reg", &host->cs);
 	if (ret) {
@@ -2955,6 +2952,9 @@  static int qcom_nand_host_init_and_register(struct qcom_nand_controller *nandc,
 	if (ret)
 		return ret;
 
+	cwperpage = mtd->writesize / NANDC_STEP_SIZE;
+	nandc->max_cwperpage = max_t(unsigned int, nandc->max_cwperpage,
+				     cwperpage);
 	if (nandc->props->is_bam) {
 		free_bam_transaction(nandc);
 		nandc->bam_txn = alloc_bam_transaction(nandc);