[U-Boot] [PATCH] sf: Correct data types in stm_is_locked_sr()

[Jagan Teki]

Hi Marek,

On 12 March 2016 at 00:29, Marek Vasut <marex at denx.de> wrote:
> On 03/11/2016 07:44 PM, Jagan Teki wrote:
>> On 12 March 2016 at 00:03, Marek Vasut <marex at denx.de> wrote:
>>> On 03/11/2016 07:07 PM, Jagan Teki wrote:
>>>> On 11 March 2016 at 23:32, Marek Vasut <marex at denx.de> wrote:
>>>>> On 03/11/2016 06:34 PM, Jagan Teki wrote:
>>>>>> On 11 March 2016 at 17:59, Marek Vasut <marex at denx.de> wrote:
>>>>>>> On 03/11/2016 07:39 AM, Jagan Teki wrote:
>>>>>>>> On 11 March 2016 at 07:50, Marek Vasut <marex at denx.de> wrote:
>>>>>>>>> The stm_is_locked_sr() function is picked from Linux kernel. For reason
>>>>>>>>> unknown, the 64bit data types used by the function and present in Linux
>>>>>>>>> were replaced with 32bit unsigned ones, which causes trouble.
>>>>>>>>>
>>>>>>>>> The testcase performed was done using ST M25P80 chip.
>>>>>>>>> The command used was:
>>>>>>>>>  => sf protect unlock 0 0x10000
>>>>>>>>>
>>>>>>>>> The call chain starts in stm_unlock(), which calls stm_is_locked_sr()
>>>>>>>>> with negative ofs argument. This works fine in Linux, where the "ofs"
>>>>>>>>> is loff_t, which is signed long long, while this fails in U-Boot, where
>>>>>>>>> "ofs" is u32 (unsigned int). Because of this signedness problem, the
>>>>>>>>> expression past the return statement to be incorrectly evaluated to 1,
>>>>>>>>> which in turn propagates back to stm_unlock() and results in -EINVAL.
>>>>>>>>>
>>>>>>>>> The correction is very simple, just use the correctly sized data types
>>>>>>>>> with correct signedness in the function to make it work as intended.
>>>>>>>>>
>>>>>>>>> Signed-off-by: Marek Vasut <marex at denx.de>
>>>>>>>>> Cc: Simon Glass <sjg at chromium.org>
>>>>>>>>> Cc: Jagan Teki <jteki at openedev.com>
>>>>>>>>> ---
>>>>>>>>>  drivers/mtd/spi/spi_flash.c | 6 +++---
>>>>>>>>>  1 file changed, 3 insertions(+), 3 deletions(-)
>>>>>>>>>
>>>>>>>>> diff --git a/drivers/mtd/spi/spi_flash.c b/drivers/mtd/spi/spi_flash.c
>>>>>>>>> index 2ae2e3c..44d9e9b 100644
>>>>>>>>> --- a/drivers/mtd/spi/spi_flash.c
>>>>>>>>> +++ b/drivers/mtd/spi/spi_flash.c
>>>>>>>>> @@ -665,7 +665,7 @@ int sst_write_bp(struct spi_flash *flash, u32 offset, size_t len,
>>>>>>>>>
>>>>>>>>>  #if defined(CONFIG_SPI_FLASH_STMICRO) || defined(CONFIG_SPI_FLASH_SST)
>>>>>>>>>  static void stm_get_locked_range(struct spi_flash *flash, u8 sr, loff_t *ofs,
>>>>>>>>> -                                u32 *len)
>>>>>>>>> +                                u64 *len)
>>>>>>>>
>>>>>>>> What about uint64_t?
>>>>>>>
>>>>>>> This is now same as Linux too.
>>>>>>
>>>>>> I couldn't find it on l2-mtd and ML as well, it is still uint64_t
>>>>>>
>>>>> You are not supposed to use stdint.h types in either kernel or u-boot if
>>>>> this is what you are concerned about. Thus, u64.
>>>>
>>>> No, I'm saying Linux is still using uint64_t and why can't we use the same?
>>>>
>>> Very quick google search gets you for example here:
>>>
>>> http://article.gmane.org/gmane.linux.kernel/259313
>>>
>>> Quote:
>>> "
>>> In short: having the kernel use the same names as user space is ACTIVELY
>>> BAD, exactly because those names have standards-defined visibility,
>>> which means that the kernel _cannot_ use them in all places anyway. So
>>> don't even _try_.
>>> "
>>
>> Yes, clear I knew this too - but this protect code is a copy from
>> Linux it better to be the same. ie only my concern.
>
> Thus, linux should be fixed.

I think Linux look OK with using uint64_t as offset and remaining were
not using not uNN and issue with u-boot only as you mentioned on the
log message.

thanks!
-- 
Jagan.