Re: [tip:x86/pti] x86/spectre: Add boot time option to select Spectre v2 mitigation

From: Thomas Gleixner
Date: Wed Jan 10 2018 - 13:07:15 EST


On Wed, 10 Jan 2018, Tom Lendacky wrote:
> > +retpoline_auto:
> > + if (boot_cpu_data.x86_vendor == X86_VENDOR_AMD) {
>
> Not specifying anything on the command line will get SPECTRE_V2_CMD_AUTO,
> so boot_cpu_has(X86_FEATURE_LFENCE_RDTSC) needs to be checked since it
> won't have been checked previously.

Dammit.