Re: [PATCH 2/2] task_work: check callback if it's NULL

[Li Zefan <lizefan@huawei.com>]

On 2013/3/15 8:20, li guang wrote:
> 在 2013-03-14四的 15:43 +0100，Oleg Nesterov写道：
>> On 03/14, liguang wrote:
>>>
>>> Signed-off-by: liguang <lig.fnst@cn.fujitsu.com>
>>> ---
>>>  kernel/task_work.c |    3 ++-
>>>  1 files changed, 2 insertions(+), 1 deletions(-)
>>>
>>> diff --git a/kernel/task_work.c b/kernel/task_work.c
>>> index 0bf4258..f458b08 100644
>>> --- a/kernel/task_work.c
>>> +++ b/kernel/task_work.c
>>> @@ -75,7 +75,8 @@ void task_work_run(void)
>>>
>>>  		do {
>>>  			next = work->next;
>>> -			work->func(work);
>>> +			if (unlikely(work->func))
>>> +				work->func(work);
>>
>> Why?
>>
>> Oleg.
>>
> 
> can we believe a callback always be call-able?
> can it happened to be 0? e.g. wrong initialized.
> of course, we can complain the caller, be why don't
> we easily make it more safer?
> 

Because you're not making things safer, but your're trying
to cover up bugs...