Re: [PATCH 1/3] memtest: use kstrtouint instead of simple_strtoul

[Vladimir Murzin <vladimir.murzin@arm.com>]

On 20/06/15 07:55, Leon Romanovsky wrote:
> On Fri, Jun 19, 2015 at 5:58 PM, Vladimir Murzin
> <vladimir.murzin@arm.com> wrote:
>> Since simple_strtoul is obsolete and memtest_pattern is type of int, use
>> kstrtouint instead.
>>
>> Signed-off-by: Vladimir Murzin <vladimir.murzin@arm.com>
>> ---
>>  mm/memtest.c |   14 +++++++++-----
>>  1 file changed, 9 insertions(+), 5 deletions(-)
>>
>> diff --git a/mm/memtest.c b/mm/memtest.c
>> index 1997d93..895a43c 100644
>> --- a/mm/memtest.c
>> +++ b/mm/memtest.c
>> @@ -88,14 +88,18 @@ static void __init do_one_pass(u64 pattern, phys_addr_t start, phys_addr_t end)
>>  }
>>
>>  /* default is disabled */
>> -static int memtest_pattern __initdata;
>> +static unsigned int memtest_pattern __initdata;
>>
>>  static int __init parse_memtest(char *arg)
>>  {
>> -       if (arg)
>> -               memtest_pattern = simple_strtoul(arg, NULL, 0);
>> -       else
>> -               memtest_pattern = ARRAY_SIZE(patterns);
>> +       if (arg) {
>> +               int err = kstrtouint(arg, 0, &memtest_pattern);
>> +
>> +               if (!err)
>> +                       return 0;
> kstrtouint returns 0 for success, in case of error you will fallback
> and execute following line. It is definetely change of behaviour.

I'd be glad if you can elaborate more on use cases dependent on this
change? I can only imagine providing garbage to the memtest option with
only intention to shut it up... but it looks like the interface abuse
since "memtest=0" does exactly the same.

Since memtest is debugging option and numeric parameter is optional I
thought it was not harmful to fallback to default in case something is
wrong with the parameter.

Thanks
Vladimir

>> +       }
>> +
>> +       memtest_pattern = ARRAY_SIZE(patterns);
>>
>>         return 0;
>>  }
>> --
>> 1.7.9.5
>>
>> --
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> 
> 
> 

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