Re: [patch 1/2] x86/tsc: Validate TSC_ADJUST after resume

From: Peter Zijlstra
Date: Tue Dec 13 2016 - 08:23:19 EST


On Tue, Dec 13, 2016 at 01:14:17PM -0000, Thomas Gleixner wrote:
> --- a/arch/x86/power/cpu.c
> +++ b/arch/x86/power/cpu.c
> @@ -256,6 +256,7 @@ static void notrace __restore_processor_
> mtrr_bp_restore();
> perf_restore_debug_store();
> msr_restore_context(ctxt);
> + tsc_verify_tsc_adjust(true);
> }

Should we do that sooner, as in before calling
restore_sched_clock_state() ? Otherwise we recompute the sched_clock
deltas vs the wrecked TSC and then fix it up through the ADJUST,
wrecking our sched clock again.