Re: [Patch v5 11/16] x86/speculation: Add Spectre v2 app to app protection modes

[Tim Chen]

On 11/19/2018 07:00 AM, Thomas Gleixner wrote:
> On Fri, 16 Nov 2018, Tim Chen wrote:
>> +DEFINE_STATIC_KEY_FALSE(spectre_v2_app_lite);
>> +EXPORT_SYMBOL_GPL(spectre_v2_app_lite);
> 
> Why would this be exported? The only usage site outside of this code is in
> tlb.c which is hardly modular.

That was my initial thought too.  Ingo suggested to export it in
review of v2.  Wonder Ingo has some reason?

https://lore.kernel.org/patchwork/patch/991759/

> 
>> @@ -328,14 +411,19 @@ static bool stibp_needed(void)
>>  	/*
>>  	 * Determine if STIBP should be always on.
>>  	 * Using enhanced IBRS makes using STIBP unnecessary.
>> +	 * For lite option, STIBP is used only for task with
>> +	 * TIF_STIBP flag. STIBP is not always on for that case.
> 
> Having the comment detached from the code is really not helpful.
> 

Sorry, would have the comment moved.

Tim