Messages in this thread | | | Date | Sun, 21 Jan 2018 20:04:30 +0100 | From | Borislav Petkov <> | Subject | Re: [PATCH v2 5/8] x86/speculation: Add basic support for IBPB |
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On Sun, Jan 21, 2018 at 06:54:22PM +0000, David Woodhouse wrote: > Because we're backporting this to every stable kernel under the sun, > and they don't already require asm-goto.
Considering the cost of the barrier, I'd simplify the whole endeavor *considerably* for backporting:
if (boot_cpu_has(X86_FEATURE_IBPB)) wrmsr(MSR_IA32_PRED_CMD, PRED_CMD_IBPB, 0);
Problem solved.
Upstream can then do static_cpu_has() if it wants to.
-- Regards/Gruss, Boris.
Good mailing practices for 400: avoid top-posting and trim the reply.
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