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

[Jagan Teki]

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.

thanks!
-- 
Jagan.