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

[Marek Vasut]

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.

-- 
Best regards,
Marek Vasut