[PATCH v2 0/6] ARM branch predictor hardening

[Marc Zyngier]

On 10/01/18 16:50, Nishanth Menon wrote:
> On 01/08/2018 12:55 PM, Marc Zyngier wrote:
>> This small series implements some basic BP hardening by invalidating
>> the BTB on CPUs that are known to be susceptible to aliasing attacks.
>>
>> These patches are closely modelled against what we do on arm64,
>> although simpler as we can rely on an architected instruction to
>> perform the invalidation. The notable exception is Cortex-A15, where
>> BTB invalidation behaves like a NOP, and the only way to shoot the
>> predictor down is to invalidate the icache *and* to have ACTLR[0] set
>> to 1 (which is a secure-only operation).
>>
> 
> 
> btw, just wanted to understand if we had any reasons as to why 
> we'arent tagging these for stable? Yes, I am aware of Greg's comments 
> in [1], but the v7 series impacts a heck of a lot of existing products 
> and is not that extensive to cause too much of a pain is it?
> 
> OR, am I missing some thing else?
> 
> [1] http://www.kroah.com/log/blog/2018/01/06/meltdown-status/

This is a work in progress. It is not ready for being merged yet. It can
be backported to stable after being merged into mainline.

Thanks,

	M.
-- 
Jazz is not dead. It just smells funny...