[PATCH] mtd: fix calculating partition end address

[PATCH] mtd: fix calculating partition end address

[Rafał Miłecki]

From: Rafał Miłecki <rafal@milecki.pl>

This fixes check for partitions that don't start at beginning of their
parents. Missing partition's offset in formula could result in forcing
read-only incorrectly.

Fixes: 6750f61a13a0 ("mtd: improve calculating partition boundaries when checking for alignment")
Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
---
 drivers/mtd/mtdpart.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/mtd/mtdpart.c b/drivers/mtd/mtdpart.c
index 7328c066c5ba..c683b432cc5e 100644
--- a/drivers/mtd/mtdpart.c
+++ b/drivers/mtd/mtdpart.c
@@ -524,7 +524,7 @@ static struct mtd_part *allocate_partition(struct mtd_info *parent,
 			part->name);
 	}
 
-	tmp = part_absolute_offset(parent) + slave->mtd.size;
+	tmp = part_absolute_offset(parent) + slave->offset + slave->mtd.size;
 	remainder = do_div(tmp, wr_alignment);
 	if ((slave->mtd.flags & MTD_WRITEABLE) && remainder) {
 		slave->mtd.flags &= ~MTD_WRITEABLE;
-- 
2.25.0


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Re: [PATCH] mtd: fix calculating partition end address

[Miquel Raynal]

Hi Rafał,

Rafał Miłecki <zajec5@gmail.com> wrote on Mon,  9 Mar 2020 08:44:45
+0100:

> From: Rafał Miłecki <rafal@milecki.pl>
> 
> This fixes check for partitions that don't start at beginning of their
> parents. Missing partition's offset in formula could result in forcing
> read-only incorrectly.
> 
> Fixes: 6750f61a13a0 ("mtd: improve calculating partition boundaries when checking for alignment")
> Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
> ---
>  drivers/mtd/mtdpart.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/mtd/mtdpart.c b/drivers/mtd/mtdpart.c
> index 7328c066c5ba..c683b432cc5e 100644
> --- a/drivers/mtd/mtdpart.c
> +++ b/drivers/mtd/mtdpart.c
> @@ -524,7 +524,7 @@ static struct mtd_part *allocate_partition(struct mtd_info *parent,
>  			part->name);
>  	}
>  
> -	tmp = part_absolute_offset(parent) + slave->mtd.size;
> +	tmp = part_absolute_offset(parent) + slave->offset + slave->mtd.size;

I think you are doing the change at the wrong place, if you want to
check where the partition *starts* you should do it a few lines above.
But I think the check should be here as well, probably.

Anyway, I just applied on my local tree a patch rewriting a bit the
partitioning scheme, could you please rebase on top of today's
mtd/next and resend this patch updated?

Here is the change that I've done at this place:
	-       tmp = part_absolute_offset(parent) + slave->mtd.size;
	+       tmp = mtd_get_master_ofs(child, 0) + child->size;

Thanks!
Miquèl

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Re: [PATCH] mtd: fix calculating partition end address

[Rafał Miłecki]

On 2020-03-09 15:04, Miquel Raynal wrote:
> Rafał Miłecki <zajec5@gmail.com> wrote on Mon,  9 Mar 2020 08:44:45
> +0100:
> 
>> From: Rafał Miłecki <rafal@milecki.pl>
>> 
>> This fixes check for partitions that don't start at beginning of their
>> parents. Missing partition's offset in formula could result in forcing
>> read-only incorrectly.
>> 
>> Fixes: 6750f61a13a0 ("mtd: improve calculating partition boundaries 
>> when checking for alignment")
>> Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
>> ---
>>  drivers/mtd/mtdpart.c | 2 +-
>>  1 file changed, 1 insertion(+), 1 deletion(-)
>> 
>> diff --git a/drivers/mtd/mtdpart.c b/drivers/mtd/mtdpart.c
>> index 7328c066c5ba..c683b432cc5e 100644
>> --- a/drivers/mtd/mtdpart.c
>> +++ b/drivers/mtd/mtdpart.c
>> @@ -524,7 +524,7 @@ static struct mtd_part *allocate_partition(struct 
>> mtd_info *parent,
>>  			part->name);
>>  	}
>> 
>> -	tmp = part_absolute_offset(parent) + slave->mtd.size;
>> +	tmp = part_absolute_offset(parent) + slave->offset + 
>> slave->mtd.size;
> 
> I think you are doing the change at the wrong place, if you want to
> check where the partition *starts* you should do it a few lines above.
> But I think the check should be here as well, probably.

The check where the partition *starts* is OK and I don't mean to change
it. The bug is about calculating absolute *end* address of partition.


> Anyway, I just applied on my local tree a patch rewriting a bit the
> partitioning scheme, could you please rebase on top of today's
> mtd/next and resend this patch updated?
> 
> Here is the change that I've done at this place:
> 	-       tmp = part_absolute_offset(parent) + slave->mtd.size;
> 	+       tmp = mtd_get_master_ofs(child, 0) + child->size;

I'll give it a try.

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Re: [PATCH] mtd: fix calculating partition end address

[Miquel Raynal]

Hi Rafał,

Rafał Miłecki <rafal@milecki.pl> wrote on Mon, 09 Mar 2020 15:19:10
+0100:

> On 2020-03-09 15:04, Miquel Raynal wrote:
> > Rafał Miłecki <zajec5@gmail.com> wrote on Mon,  9 Mar 2020 08:44:45
> > +0100:
> >   
> >> From: Rafał Miłecki <rafal@milecki.pl>  
> >> >> This fixes check for partitions that don't start at beginning of their  
> >> parents. Missing partition's offset in formula could result in forcing
> >> read-only incorrectly.  
> >> >> Fixes: 6750f61a13a0 ("mtd: improve calculating partition boundaries >> when checking for alignment")  
> >> Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
> >> ---
> >>  drivers/mtd/mtdpart.c | 2 +-
> >>  1 file changed, 1 insertion(+), 1 deletion(-)  
> >> >> diff --git a/drivers/mtd/mtdpart.c b/drivers/mtd/mtdpart.c  
> >> index 7328c066c5ba..c683b432cc5e 100644
> >> --- a/drivers/mtd/mtdpart.c
> >> +++ b/drivers/mtd/mtdpart.c
> >> @@ -524,7 +524,7 @@ static struct mtd_part *allocate_partition(struct >> mtd_info *parent,
> >>  			part->name);
> >>  	}  
> >> >> -	tmp = part_absolute_offset(parent) + slave->mtd.size;  
> >> +	tmp = part_absolute_offset(parent) + slave->offset + >> slave->mtd.size;  
> > 
> > I think you are doing the change at the wrong place, if you want to
> > check where the partition *starts* you should do it a few lines above.
> > But I think the check should be here as well, probably.  
> 
> The check where the partition *starts* is OK and I don't mean to change
> it. The bug is about calculating absolute *end* address of partition.

Can you detail a little bit then? Because I don't see the issue anymore
even though I am convinced something is wrong here :)

> 
> 
> > Anyway, I just applied on my local tree a patch rewriting a bit the
> > partitioning scheme, could you please rebase on top of today's
> > mtd/next and resend this patch updated?
> > 
> > Here is the change that I've done at this place:
> > 	-       tmp = part_absolute_offset(parent) + slave->mtd.size;
> > 	+       tmp = mtd_get_master_ofs(child, 0) + child->size;  
> 
> I'll give it a try.

Thanks,
Miquèl

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Re: [PATCH] mtd: fix calculating partition end address

[Rafał Miłecki]

On 09.03.2020 15:22, Miquel Raynal wrote:
> Rafał Miłecki <rafal@milecki.pl> wrote on Mon, 09 Mar 2020 15:19:10
> +0100:
> 
>> On 2020-03-09 15:04, Miquel Raynal wrote:
>>> Rafał Miłecki <zajec5@gmail.com> wrote on Mon,  9 Mar 2020 08:44:45
>>> +0100:
>>>    
>>>> From: Rafał Miłecki <rafal@milecki.pl>
>>>>>> This fixes check for partitions that don't start at beginning of their
>>>> parents. Missing partition's offset in formula could result in forcing
>>>> read-only incorrectly.
>>>>>> Fixes: 6750f61a13a0 ("mtd: improve calculating partition boundaries >> when checking for alignment")
>>>> Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
>>>> ---
>>>>   drivers/mtd/mtdpart.c | 2 +-
>>>>   1 file changed, 1 insertion(+), 1 deletion(-)
>>>>>> diff --git a/drivers/mtd/mtdpart.c b/drivers/mtd/mtdpart.c
>>>> index 7328c066c5ba..c683b432cc5e 100644
>>>> --- a/drivers/mtd/mtdpart.c
>>>> +++ b/drivers/mtd/mtdpart.c
>>>> @@ -524,7 +524,7 @@ static struct mtd_part *allocate_partition(struct >> mtd_info *parent,
>>>>   			part->name);
>>>>   	}
>>>>>> -	tmp = part_absolute_offset(parent) + slave->mtd.size;
>>>> +	tmp = part_absolute_offset(parent) + slave->offset + >> slave->mtd.size;
>>>
>>> I think you are doing the change at the wrong place, if you want to
>>> check where the partition *starts* you should do it a few lines above.
>>> But I think the check should be here as well, probably.
>>
>> The check where the partition *starts* is OK and I don't mean to change
>> it. The bug is about calculating absolute *end* address of partition.
> 
> Can you detail a little bit then? Because I don't see the issue anymore
> even though I am convinced something is wrong here :)

Please consider following partitions layout:
* bcm47xxsflash
├─ boot		0x000000000000-0x000000040000
└┬ firmware	0x000000040000-0x000001000000
  ├─ linux	0x00000000001c-0x00000018f800
  └┬ container	0x00000018f800-0x000000fc0000
   ├─ foo	0x000000000000-0x000000630800
   └─ bar	0x000000630800-0x000000e30800 (size: 0x800000)


Existing (correct) *start* calculation:
bar start: 0 + 0x040000 + 0x18f800 + 0x630800 = 0x800000

Existing (wrong) end calculation:
bar end: 0 + 0x040000 + 0x18f800 + 0x800000 = 0x9cf800

Fixed (correct) end calculation:
bar end: 0 + 0x040000 + 0x18f800 + 0x630800 + 0x800000 = 0x1000000


Because of that existing wrong end calculation I was getting:
mtd: partition "bar" doesn't end on an erase/write block -- force read-only

See:
2 bcm47xxpart partitions found on MTD device bcm47xxsflash
Creating 2 MTD partitions on "bcm47xxsflash":
0x000000000000-0x000000040000 : "boot"
0x000000040000-0x000001000000 : "firmware"
2 trx partitions found on MTD device firmware
Creating 2 MTD partitions on "firmware":
0x00000000001c-0x00000018f800 : "linux"
mtd: partition "linux" doesn't start on an erase/write block boundary -- force read-only
0x00000018f800-0x000000fc0000 : "container"
mtd: partition "container" doesn't start on an erase/write block boundary -- force read-only
2 container partitions found on MTD device container
Creating 2 MTD partitions on "container":
0x000000000000-0x000000630800 : "foo"
mtd: partition "foo" doesn't start on an erase/write block boundary -- force read-only
0x000000630800-0x000000e30800 : "bar"
mtd: partition "bar" doesn't end on an erase/write block -- force read-only

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Re: [PATCH] mtd: fix calculating partition end address

[Miquel Raynal]

Hi Rafał,

Rafał Miłecki <rafal@milecki.pl> wrote on Mon, 9 Mar 2020 16:08:12
+0100:

> On 09.03.2020 15:22, Miquel Raynal wrote:
> > Rafał Miłecki <rafal@milecki.pl> wrote on Mon, 09 Mar 2020 15:19:10
> > +0100:
> >   
> >> On 2020-03-09 15:04, Miquel Raynal wrote:  
> >>> Rafał Miłecki <zajec5@gmail.com> wrote on Mon,  9 Mar 2020 08:44:45
> >>> +0100:  
> >>>    >>>> From: Rafał Miłecki <rafal@milecki.pl>  
> >>>>>> This fixes check for partitions that don't start at beginning of their  
> >>>> parents. Missing partition's offset in formula could result in forcing
> >>>> read-only incorrectly.  
> >>>>>> Fixes: 6750f61a13a0 ("mtd: improve calculating partition boundaries >> when checking for alignment")  
> >>>> Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
> >>>> ---
> >>>>   drivers/mtd/mtdpart.c | 2 +-
> >>>>   1 file changed, 1 insertion(+), 1 deletion(-)  
> >>>>>> diff --git a/drivers/mtd/mtdpart.c b/drivers/mtd/mtdpart.c  
> >>>> index 7328c066c5ba..c683b432cc5e 100644
> >>>> --- a/drivers/mtd/mtdpart.c
> >>>> +++ b/drivers/mtd/mtdpart.c
> >>>> @@ -524,7 +524,7 @@ static struct mtd_part *allocate_partition(struct >> mtd_info *parent,
> >>>>   			part->name);
> >>>>   	}  
> >>>>>> -	tmp = part_absolute_offset(parent) + slave->mtd.size;  
> >>>> +	tmp = part_absolute_offset(parent) + slave->offset + >> slave->mtd.size;  
> >>>
> >>> I think you are doing the change at the wrong place, if you want to
> >>> check where the partition *starts* you should do it a few lines above.
> >>> But I think the check should be here as well, probably.  
> >>
> >> The check where the partition *starts* is OK and I don't mean to change
> >> it. The bug is about calculating absolute *end* address of partition.  
> > 
> > Can you detail a little bit then? Because I don't see the issue anymore
> > even though I am convinced something is wrong here :)  
> 
> Please consider following partitions layout:
> * bcm47xxsflash
> ├─ boot		0x000000000000-0x000000040000
> └┬ firmware	0x000000040000-0x000001000000
>   ├─ linux	0x00000000001c-0x00000018f800
>   └┬ container	0x00000018f800-0x000000fc0000
>    ├─ foo	0x000000000000-0x000000630800
>    └─ bar	0x000000630800-0x000000e30800 (size: 0x800000)
> 
> 
> Existing (correct) *start* calculation:
> bar start: 0 + 0x040000 + 0x18f800 + 0x630800 = 0x800000
> 
> Existing (wrong) end calculation:
> bar end: 0 + 0x040000 + 0x18f800 + 0x800000 = 0x9cf800
> 
> Fixed (correct) end calculation:
> bar end: 0 + 0x040000 + 0x18f800 + 0x630800 + 0x800000 = 0x1000000

Ok I get it! I think mentioning "partitions that don't start at
beginning of their parents", despite being true, was misleading to me
as I understood "leaving extra space with the start of their parent".

I suppose you also have the issue with "container" too?

Anyway, I think the fix is fine. A better formulation for the commit
log would be welcome :) (maybe adding this example is a good idea!)


Thanks,
Miquèl

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Re: [PATCH] mtd: fix calculating partition end address

[Miquel Raynal]

Hi Rafal,

Miquel Raynal <miquel.raynal@bootlin.com> wrote on Mon, 9 Mar 2020
16:22:23 +0100:

> Hi Rafał,
> 
> Rafał Miłecki <rafal@milecki.pl> wrote on Mon, 9 Mar 2020 16:08:12
> +0100:
> 
> > On 09.03.2020 15:22, Miquel Raynal wrote:  
> > > Rafał Miłecki <rafal@milecki.pl> wrote on Mon, 09 Mar 2020 15:19:10
> > > +0100:
> > >     
> > >> On 2020-03-09 15:04, Miquel Raynal wrote:    
> > >>> Rafał Miłecki <zajec5@gmail.com> wrote on Mon,  9 Mar 2020 08:44:45
> > >>> +0100:    
> > >>>    >>>> From: Rafał Miłecki <rafal@milecki.pl>    
> > >>>>>> This fixes check for partitions that don't start at beginning of their    
> > >>>> parents. Missing partition's offset in formula could result in forcing
> > >>>> read-only incorrectly.    
> > >>>>>> Fixes: 6750f61a13a0 ("mtd: improve calculating partition boundaries >> when checking for alignment")    
> > >>>> Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
> > >>>> ---
> > >>>>   drivers/mtd/mtdpart.c | 2 +-
> > >>>>   1 file changed, 1 insertion(+), 1 deletion(-)    
> > >>>>>> diff --git a/drivers/mtd/mtdpart.c b/drivers/mtd/mtdpart.c    
> > >>>> index 7328c066c5ba..c683b432cc5e 100644
> > >>>> --- a/drivers/mtd/mtdpart.c
> > >>>> +++ b/drivers/mtd/mtdpart.c
> > >>>> @@ -524,7 +524,7 @@ static struct mtd_part *allocate_partition(struct >> mtd_info *parent,
> > >>>>   			part->name);
> > >>>>   	}    
> > >>>>>> -	tmp = part_absolute_offset(parent) + slave->mtd.size;    
> > >>>> +	tmp = part_absolute_offset(parent) + slave->offset + >> slave->mtd.size;    
> > >>>
> > >>> I think you are doing the change at the wrong place, if you want to
> > >>> check where the partition *starts* you should do it a few lines above.
> > >>> But I think the check should be here as well, probably.    
> > >>
> > >> The check where the partition *starts* is OK and I don't mean to change
> > >> it. The bug is about calculating absolute *end* address of partition.    
> > > 
> > > Can you detail a little bit then? Because I don't see the issue anymore
> > > even though I am convinced something is wrong here :)    
> > 
> > Please consider following partitions layout:
> > * bcm47xxsflash
> > ├─ boot		0x000000000000-0x000000040000
> > └┬ firmware	0x000000040000-0x000001000000
> >   ├─ linux	0x00000000001c-0x00000018f800
> >   └┬ container	0x00000018f800-0x000000fc0000
> >    ├─ foo	0x000000000000-0x000000630800
> >    └─ bar	0x000000630800-0x000000e30800 (size: 0x800000)
> > 
> > 
> > Existing (correct) *start* calculation:
> > bar start: 0 + 0x040000 + 0x18f800 + 0x630800 = 0x800000
> > 
> > Existing (wrong) end calculation:
> > bar end: 0 + 0x040000 + 0x18f800 + 0x800000 = 0x9cf800
> > 
> > Fixed (correct) end calculation:
> > bar end: 0 + 0x040000 + 0x18f800 + 0x630800 + 0x800000 = 0x1000000  
> 
> Ok I get it! I think mentioning "partitions that don't start at
> beginning of their parents", despite being true, was misleading to me
> as I understood "leaving extra space with the start of their parent".
> 
> I suppose you also have the issue with "container" too?
> 
> Anyway, I think the fix is fine. A better formulation for the commit
> log would be welcome :) (maybe adding this example is a good idea!)

I don't remember having applied this fix yet, would you mind resending
this patch with an enhanced commit log (your example was a good one I
think).

Thanks,
 Miquèl

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Re: [PATCH] mtd: fix calculating partition end address

[Rafał Miłecki]

On 2020-05-02 20:04, Miquel Raynal wrote:
> Miquel Raynal <miquel.raynal@bootlin.com> wrote on Mon, 9 Mar 2020
> 16:22:23 +0100:
> 
>> Hi Rafał,
>> 
>> Rafał Miłecki <rafal@milecki.pl> wrote on Mon, 9 Mar 2020 16:08:12
>> +0100:
>> 
>> > On 09.03.2020 15:22, Miquel Raynal wrote:
>> > > Rafał Miłecki <rafal@milecki.pl> wrote on Mon, 09 Mar 2020 15:19:10
>> > > +0100:
>> > >
>> > >> On 2020-03-09 15:04, Miquel Raynal wrote:
>> > >>> Rafał Miłecki <zajec5@gmail.com> wrote on Mon,  9 Mar 2020 08:44:45
>> > >>> +0100:
>> > >>>    >>>> From: Rafał Miłecki <rafal@milecki.pl>
>> > >>>>>> This fixes check for partitions that don't start at beginning of their
>> > >>>> parents. Missing partition's offset in formula could result in forcing
>> > >>>> read-only incorrectly.
>> > >>>>>> Fixes: 6750f61a13a0 ("mtd: improve calculating partition boundaries >> when checking for alignment")
>> > >>>> Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
>> > >>>> ---
>> > >>>>   drivers/mtd/mtdpart.c | 2 +-
>> > >>>>   1 file changed, 1 insertion(+), 1 deletion(-)
>> > >>>>>> diff --git a/drivers/mtd/mtdpart.c b/drivers/mtd/mtdpart.c
>> > >>>> index 7328c066c5ba..c683b432cc5e 100644
>> > >>>> --- a/drivers/mtd/mtdpart.c
>> > >>>> +++ b/drivers/mtd/mtdpart.c
>> > >>>> @@ -524,7 +524,7 @@ static struct mtd_part *allocate_partition(struct >> mtd_info *parent,
>> > >>>>   			part->name);
>> > >>>>   	}
>> > >>>>>> -	tmp = part_absolute_offset(parent) + slave->mtd.size;
>> > >>>> +	tmp = part_absolute_offset(parent) + slave->offset + >> slave->mtd.size;
>> > >>>
>> > >>> I think you are doing the change at the wrong place, if you want to
>> > >>> check where the partition *starts* you should do it a few lines above.
>> > >>> But I think the check should be here as well, probably.
>> > >>
>> > >> The check where the partition *starts* is OK and I don't mean to change
>> > >> it. The bug is about calculating absolute *end* address of partition.
>> > >
>> > > Can you detail a little bit then? Because I don't see the issue anymore
>> > > even though I am convinced something is wrong here :)
>> >
>> > Please consider following partitions layout:
>> > * bcm47xxsflash
>> > ├─ boot		0x000000000000-0x000000040000
>> > └┬ firmware	0x000000040000-0x000001000000
>> >   ├─ linux	0x00000000001c-0x00000018f800
>> >   └┬ container	0x00000018f800-0x000000fc0000
>> >    ├─ foo	0x000000000000-0x000000630800
>> >    └─ bar	0x000000630800-0x000000e30800 (size: 0x800000)
>> >
>> >
>> > Existing (correct) *start* calculation:
>> > bar start: 0 + 0x040000 + 0x18f800 + 0x630800 = 0x800000
>> >
>> > Existing (wrong) end calculation:
>> > bar end: 0 + 0x040000 + 0x18f800 + 0x800000 = 0x9cf800
>> >
>> > Fixed (correct) end calculation:
>> > bar end: 0 + 0x040000 + 0x18f800 + 0x630800 + 0x800000 = 0x1000000
>> 
>> Ok I get it! I think mentioning "partitions that don't start at
>> beginning of their parents", despite being true, was misleading to me
>> as I understood "leaving extra space with the start of their parent".
>> 
>> I suppose you also have the issue with "container" too?
>> 
>> Anyway, I think the fix is fine. A better formulation for the commit
>> log would be welcome :) (maybe adding this example is a good idea!)
> 
> I don't remember having applied this fix yet, would you mind resending
> this patch with an enhanced commit log (your example was a good one I
> think).

It's not needed anymore. Please check discussion we got:

-------- Original Message --------
Subject: Re: [PATCH] mtd: fix calculating partition end address
Date: 2020-03-24 23:11

> > I would like to apply your fix this week, do you think you can rebase
> > and resend soon?
> 
> It's not needed anymore as you fixed this bug in your commit reworking
> partitions.

Great!

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Re: [PATCH] mtd: fix calculating partition end address

[Miquel Raynal]

Hi Rafał,

Rafał Miłecki <rafal@milecki.pl> wrote on Sat, 02 May 2020 21:36:24
+0200:

> On 2020-05-02 20:04, Miquel Raynal wrote:
> > Miquel Raynal <miquel.raynal@bootlin.com> wrote on Mon, 9 Mar 2020
> > 16:22:23 +0100:
> >   
> >> Hi Rafał,  
> >> >> Rafał Miłecki <rafal@milecki.pl> wrote on Mon, 9 Mar 2020 16:08:12  
> >> +0100:  
> >> >> > On 09.03.2020 15:22, Miquel Raynal wrote:  
> >> > > Rafał Miłecki <rafal@milecki.pl> wrote on Mon, 09 Mar 2020 15:19:10
> >> > > +0100:
> >> > >  
> >> > >> On 2020-03-09 15:04, Miquel Raynal wrote:  
> >> > >>> Rafał Miłecki <zajec5@gmail.com> wrote on Mon,  9 Mar 2020 08:44:45
> >> > >>> +0100:  
> >> > >>>    >>>> From: Rafał Miłecki <rafal@milecki.pl>  
> >> > >>>>>> This fixes check for partitions that don't start at beginning of their  
> >> > >>>> parents. Missing partition's offset in formula could result in forcing
> >> > >>>> read-only incorrectly.  
> >> > >>>>>> Fixes: 6750f61a13a0 ("mtd: improve calculating partition boundaries >> when checking for alignment")  
> >> > >>>> Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
> >> > >>>> ---
> >> > >>>>   drivers/mtd/mtdpart.c | 2 +-
> >> > >>>>   1 file changed, 1 insertion(+), 1 deletion(-)  
> >> > >>>>>> diff --git a/drivers/mtd/mtdpart.c b/drivers/mtd/mtdpart.c  
> >> > >>>> index 7328c066c5ba..c683b432cc5e 100644
> >> > >>>> --- a/drivers/mtd/mtdpart.c
> >> > >>>> +++ b/drivers/mtd/mtdpart.c
> >> > >>>> @@ -524,7 +524,7 @@ static struct mtd_part *allocate_partition(struct >> mtd_info *parent,
> >> > >>>>   			part->name);
> >> > >>>>   	}  
> >> > >>>>>> -	tmp = part_absolute_offset(parent) + slave->mtd.size;  
> >> > >>>> +	tmp = part_absolute_offset(parent) + slave->offset + >> slave->mtd.size;  
> >> > >>>
> >> > >>> I think you are doing the change at the wrong place, if you want to
> >> > >>> check where the partition *starts* you should do it a few lines above.
> >> > >>> But I think the check should be here as well, probably.  
> >> > >>
> >> > >> The check where the partition *starts* is OK and I don't mean to change
> >> > >> it. The bug is about calculating absolute *end* address of partition.  
> >> > >
> >> > > Can you detail a little bit then? Because I don't see the issue anymore
> >> > > even though I am convinced something is wrong here :)  
> >> >
> >> > Please consider following partitions layout:
> >> > * bcm47xxsflash
> >> > ├─ boot		0x000000000000-0x000000040000
> >> > └┬ firmware	0x000000040000-0x000001000000
> >> >   ├─ linux	0x00000000001c-0x00000018f800
> >> >   └┬ container	0x00000018f800-0x000000fc0000
> >> >    ├─ foo	0x000000000000-0x000000630800
> >> >    └─ bar	0x000000630800-0x000000e30800 (size: 0x800000)
> >> >
> >> >
> >> > Existing (correct) *start* calculation:
> >> > bar start: 0 + 0x040000 + 0x18f800 + 0x630800 = 0x800000
> >> >
> >> > Existing (wrong) end calculation:
> >> > bar end: 0 + 0x040000 + 0x18f800 + 0x800000 = 0x9cf800
> >> >
> >> > Fixed (correct) end calculation:
> >> > bar end: 0 + 0x040000 + 0x18f800 + 0x630800 + 0x800000 = 0x1000000  
> >> >> Ok I get it! I think mentioning "partitions that don't start at  
> >> beginning of their parents", despite being true, was misleading to me
> >> as I understood "leaving extra space with the start of their parent".  
> >> >> I suppose you also have the issue with "container" too?
> >> >> Anyway, I think the fix is fine. A better formulation for the commit  
> >> log would be welcome :) (maybe adding this example is a good idea!)  
> > 
> > I don't remember having applied this fix yet, would you mind resending
> > this patch with an enhanced commit log (your example was a good one I
> > think).  
> 
> It's not needed anymore. Please check discussion we got:
> 
> -------- Original Message --------
> Subject: Re: [PATCH] mtd: fix calculating partition end address
> Date: 2020-03-24 23:11
> 
> > > I would like to apply your fix this week, do you think you can rebase
> > > and resend soon?  
> > 
> > It's not needed anymore as you fixed this bug in your commit reworking
> > partitions.  
> 
> Great!

Yeah sorry about that, I got confused while listing remaining patches :)

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Re: [PATCH] mtd: fix calculating partition end address

[Miquel Raynal]

Hi Rafał,

Rafał Miłecki <rafal@milecki.pl> wrote on Mon, 09 Mar 2020 15:19:10
+0100:

> On 2020-03-09 15:04, Miquel Raynal wrote:
> > Rafał Miłecki <zajec5@gmail.com> wrote on Mon,  9 Mar 2020 08:44:45
> > +0100:
> >   
> >> From: Rafał Miłecki <rafal@milecki.pl>  
> >> >> This fixes check for partitions that don't start at beginning of their  
> >> parents. Missing partition's offset in formula could result in forcing
> >> read-only incorrectly.  
> >> >> Fixes: 6750f61a13a0 ("mtd: improve calculating partition boundaries >> when checking for alignment")  
> >> Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
> >> ---
> >>  drivers/mtd/mtdpart.c | 2 +-
> >>  1 file changed, 1 insertion(+), 1 deletion(-)  
> >> >> diff --git a/drivers/mtd/mtdpart.c b/drivers/mtd/mtdpart.c  
> >> index 7328c066c5ba..c683b432cc5e 100644
> >> --- a/drivers/mtd/mtdpart.c
> >> +++ b/drivers/mtd/mtdpart.c
> >> @@ -524,7 +524,7 @@ static struct mtd_part *allocate_partition(struct >> mtd_info *parent,
> >>  			part->name);
> >>  	}  
> >> >> -	tmp = part_absolute_offset(parent) + slave->mtd.size;  
> >> +	tmp = part_absolute_offset(parent) + slave->offset + >> slave->mtd.size;  
> > 
> > I think you are doing the change at the wrong place, if you want to
> > check where the partition *starts* you should do it a few lines above.
> > But I think the check should be here as well, probably.  
> 
> The check where the partition *starts* is OK and I don't mean to change
> it. The bug is about calculating absolute *end* address of partition.
> 
> 
> > Anyway, I just applied on my local tree a patch rewriting a bit the
> > partitioning scheme, could you please rebase on top of today's
> > mtd/next and resend this patch updated?
> > 
> > Here is the change that I've done at this place:
> > 	-       tmp = part_absolute_offset(parent) + slave->mtd.size;
> > 	+       tmp = mtd_get_master_ofs(child, 0) + child->size;  
> 
> I'll give it a try.

I would like to apply your fix this week, do you think you can rebase
and resend soon?

Thanks,
Miquèl

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Re: [PATCH] mtd: fix calculating partition end address

[Rafał Miłecki]

Hey,

On 2020-03-24 22:58, Miquel Raynal wrote:
> Rafał Miłecki <rafal@milecki.pl> wrote on Mon, 09 Mar 2020 15:19:10
> +0100:
> 
>> On 2020-03-09 15:04, Miquel Raynal wrote:
>> > Rafał Miłecki <zajec5@gmail.com> wrote on Mon,  9 Mar 2020 08:44:45
>> > +0100:
>> >
>> >> From: Rafał Miłecki <rafal@milecki.pl>
>> >> >> This fixes check for partitions that don't start at beginning of their
>> >> parents. Missing partition's offset in formula could result in forcing
>> >> read-only incorrectly.
>> >> >> Fixes: 6750f61a13a0 ("mtd: improve calculating partition boundaries >> when checking for alignment")
>> >> Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
>> >> ---
>> >>  drivers/mtd/mtdpart.c | 2 +-
>> >>  1 file changed, 1 insertion(+), 1 deletion(-)
>> >> >> diff --git a/drivers/mtd/mtdpart.c b/drivers/mtd/mtdpart.c
>> >> index 7328c066c5ba..c683b432cc5e 100644
>> >> --- a/drivers/mtd/mtdpart.c
>> >> +++ b/drivers/mtd/mtdpart.c
>> >> @@ -524,7 +524,7 @@ static struct mtd_part *allocate_partition(struct >> mtd_info *parent,
>> >>  			part->name);
>> >>  	}
>> >> >> -	tmp = part_absolute_offset(parent) + slave->mtd.size;
>> >> +	tmp = part_absolute_offset(parent) + slave->offset + >> slave->mtd.size;
>> >
>> > I think you are doing the change at the wrong place, if you want to
>> > check where the partition *starts* you should do it a few lines above.
>> > But I think the check should be here as well, probably.
>> 
>> The check where the partition *starts* is OK and I don't mean to 
>> change
>> it. The bug is about calculating absolute *end* address of partition.
>> 
>> 
>> > Anyway, I just applied on my local tree a patch rewriting a bit the
>> > partitioning scheme, could you please rebase on top of today's
>> > mtd/next and resend this patch updated?
>> >
>> > Here is the change that I've done at this place:
>> > 	-       tmp = part_absolute_offset(parent) + slave->mtd.size;
>> > 	+       tmp = mtd_get_master_ofs(child, 0) + child->size;
>> 
>> I'll give it a try.
> 
> I would like to apply your fix this week, do you think you can rebase
> and resend soon?

It's not needed anymore as you fixed this bug in your commit reworking
partitions.

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Re: [PATCH] mtd: fix calculating partition end address

[Miquel Raynal]

Hi Rafał,

Rafał Miłecki <rafal@milecki.pl> wrote on Tue, 24 Mar 2020 23:06:05
+0100:

> Hey,
> 
> On 2020-03-24 22:58, Miquel Raynal wrote:
> > Rafał Miłecki <rafal@milecki.pl> wrote on Mon, 09 Mar 2020 15:19:10
> > +0100:
> >   
> >> On 2020-03-09 15:04, Miquel Raynal wrote:  
> >> > Rafał Miłecki <zajec5@gmail.com> wrote on Mon,  9 Mar 2020 08:44:45
> >> > +0100:
> >> >  
> >> >> From: Rafał Miłecki <rafal@milecki.pl>  
> >> >> >> This fixes check for partitions that don't start at beginning of their  
> >> >> parents. Missing partition's offset in formula could result in forcing
> >> >> read-only incorrectly.  
> >> >> >> Fixes: 6750f61a13a0 ("mtd: improve calculating partition boundaries >> when checking for alignment")  
> >> >> Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
> >> >> ---
> >> >>  drivers/mtd/mtdpart.c | 2 +-
> >> >>  1 file changed, 1 insertion(+), 1 deletion(-)  
> >> >> >> diff --git a/drivers/mtd/mtdpart.c b/drivers/mtd/mtdpart.c  
> >> >> index 7328c066c5ba..c683b432cc5e 100644
> >> >> --- a/drivers/mtd/mtdpart.c
> >> >> +++ b/drivers/mtd/mtdpart.c
> >> >> @@ -524,7 +524,7 @@ static struct mtd_part *allocate_partition(struct >> mtd_info *parent,
> >> >>  			part->name);
> >> >>  	}  
> >> >> >> -	tmp = part_absolute_offset(parent) + slave->mtd.size;  
> >> >> +	tmp = part_absolute_offset(parent) + slave->offset + >> slave->mtd.size;  
> >> >
> >> > I think you are doing the change at the wrong place, if you want to
> >> > check where the partition *starts* you should do it a few lines above.
> >> > But I think the check should be here as well, probably.  
> >> >> The check where the partition *starts* is OK and I don't mean to >> change  
> >> it. The bug is about calculating absolute *end* address of partition.  
> >> >> >> > Anyway, I just applied on my local tree a patch rewriting a bit the  
> >> > partitioning scheme, could you please rebase on top of today's
> >> > mtd/next and resend this patch updated?
> >> >
> >> > Here is the change that I've done at this place:
> >> > 	-       tmp = part_absolute_offset(parent) + slave->mtd.size;
> >> > 	+       tmp = mtd_get_master_ofs(child, 0) + child->size;  
> >> >> I'll give it a try.  
> > 
> > I would like to apply your fix this week, do you think you can rebase
> > and resend soon?  
> 
> It's not needed anymore as you fixed this bug in your commit reworking
> partitions.

Great!


Thanks for the info
Miquèl

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