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

[Marek Vasut]

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_.
"

There are multiple discussions about the same thing in U-Boot ML as
well, I am sure you can find them yourself. I would be much more
interested in getting this fix into current release instead of
discussing some stupid type.
-- 
Best regards,
Marek Vasut