Re: [RFC V3] mm: Generalize and rename notify_page_fault() as kprobe_page_fault()

[Anshuman Khandual]

On 06/10/2019 08:57 PM, Leonardo Bras wrote:
> On Mon, 2019-06-10 at 08:09 +0530, Anshuman Khandual wrote:
>>>> +    /*
>>>> +     * To be potentially processing a kprobe fault and to be allowed
>>>> +     * to call kprobe_running(), we have to be non-preemptible.
>>>> +     */
>>>> +    if (kprobes_built_in() && !preemptible() && !user_mode(regs)) {
>>>> +        if (kprobe_running() && kprobe_fault_handler(regs, trap))
>>>
>>> don't need an 'if A if B', can do 'if A && B'
>>
>> Which will make it a very lengthy condition check.
> 
> Well, is there any problem line-breaking the if condition?
> 
> if (A && B && C &&
>     D && E )
> 
> Also, if it's used only to decide the return value, maybe would be fine
> to do somethink like that:
> 
> return (A && B && C &&
>         D && E ); 

Got it. But as Dave and Matthew had pointed out earlier, the current x86
implementation has better readability. Hence will probably stick with it.