[PATCH] [MTD] OneNAND: Do not allow oob write past end of page

[Kyungmin Park]

Hi Adrian,

> 
> OneNAND stuff which we have now is _part of MTD_. MTD has its 
> interface, its model of the device. As long as we are part of 
> this infrastructure, we have to obey MTD's interface, rules 
> and restrictions.
> 
> The whole idea of MTD is to make upper layers to access 
> flashes in a uniform layer. MTD achieves this at certain 
> extent. There are flaws, but anyway. So basically OneNAND 
> implements more then NAND in this OOB handling stuff. And it 
> is bad. It encourages other people to write OneNAND-only 
> software, incompatible with NAND, which is totally 
> unreasonable in this case.
> 

I will push it.

BTW, after patch, we got dead code.
I downloaded oobtest again, re-run it and see that it trigger exception
code in onenand_do_write_oob
But it don't touch following codes whether include your patch or not.

        /* Do not allow write past end of device */
        if (unlikely(to >= mtd->size ||
            column + len > ((mtd->size >> this->page_shift) -
                                (to >> this->page_shift)) * oobsize)) {
                DEBUG(MTD_DEBUG_LEVEL0, "onenand_write_oob: Attempted to
write past end of device\n");
                return -EINVAL;
        }

Please check oobtest program.

Thank you,
Kyungmin Park

--

oobtest: Test 4 of 5
oobtest: erasing
oobtest: erased 0
oobtest: erased 128
oobtest: Attempting to start write past end of oob
oobtest: An error is expected...
oobtest: Error occurred as expected
oobtest: Attempting to start read past end of oob
oobtest: An error is expected...
oobtest: Error occurred as expected
oobtest: Attempting to write past end of device
oobtest: An error is expected...
-> onenand_write_oob: Attempt to write past end of page
oobtest: Error occurred as expected
oobtest: Attempting to read past end of device
oobtest: An error is expected...
oobtest: error: read past end of device
oobtest: Attempting to write past end of device
oobtest: An error is expected...
-> onenand_write_oob: Attempt to write past end of page
oobtest: Error occurred as expected
oobtest: Attempting to read past end of device
oobtest: An error is expected...
oobtest: error: read past end of device