Re: [PATCH] x86/retpoline: Fix NOSPEC_JMP for tip

From: Thomas Gleixner
Date: Tue Jan 09 2018 - 20:50:22 EST


On Tue, 9 Jan 2018, Andi Kleen wrote:

> > > I think there are areas that rely on X86_FEATURE_RETPOLINE being set
> > > even if X86_FEATURE_RETPOLINE_AMD is set. For example, line 261 in
> > > arch/x86/entry/entry_32.S is only checking for X86_FEATURE_RETPOLINE.
> >
> > I audited the difference places. They all seem ok.
>
> Actually 32bit is not ok. For 32bit we need COMMON. So adding it.

Please keep the current X86_FEATURE_RETPOLINE as the common one and add a
new X86_FEATURE_RETPOLINE_GENERIC which is selected by the generic/intel
side. Little more churn, but clearer.

Thanks,

tglx