Re: [PATCH] tick/sched: check skew_tick kernel parameter's validity

[Sergey Shtylyov]

On 9/30/26 10:01 PM, Sergey Shtylyov wrote:
[...]

>>> In skew_tick(), the result of get_option() call is ignored, so even if a
>>> value of the skew_tick kernel parameter was not specified (or specified
>>> as a list or range), the kernel won't complain. Add the missing check...
>>>
>>> Found by Linux Verification Center (linuxtesting.org) with the Svace static
>>> analysis tool.
>>>
>>> Signed-off-by: Sergey Shtylyov <s.shtylyov@xxxxxxxxxxxx>
>>>
>>> ---
>>> The patch is against the timers/nohz branch of the tip.git repo...
>>>
>>>  kernel/time/tick-sched.c | 3 ++-
>>>  1 file changed, 2 insertions(+), 1 deletion(-)
>>>
>>> diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c
>>> index c1ee0b256445..34ceccdd49b5 100644
>>> --- a/kernel/time/tick-sched.c
>>> +++ b/kernel/time/tick-sched.c
>>> @@ -1483,7 +1483,8 @@ static int sched_skew_tick;
>>>
>>>  static int __init skew_tick(char *str)
>>>  {
>>> -     get_option(&str, &sched_skew_tick);
>>> +     if (get_option(&str, &sched_skew_tick) != 1)
>>> +             return -EINVAL;
>>>
>>>       return 0;
>>>  }
>>
>> sched_skew_tick should be converted to bool and this function should
>> simply do:
>>
>>        return kstrtobool(str, &sched_skew_tick);
> 
>    Thanks for your comment!
>    OK, I'll do that (and add the Suggested-by: tag, of/c)...

   One thing I did forget to ask: we still don't need the Fixes tag here?

[...]

>> Thanks,
>>
>>         tglx

MBR, Sergey