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Date: Tue, 13 Dec 2016 14:22:50 +0100
From: Peter Zijlstra <peterz@infradead.org>
To: Thomas Gleixner <tglx@linutronix.de>
Cc: LKML <linux-kernel@vger.kernel.org>, x86@kernel.org,
        Borislav Petkov <bp@alien8.de>,
        Bruce Schlobohm <bruce.schlobohm@intel.com>,
        Roland Scheidegger <rscheidegger_lists@hispeed.ch>,
        Kevin Stanton <kevin.b.stanton@intel.com>,
        Allen Hung <allen_hung@dell.com>
Subject: Re: [patch 1/2] x86/tsc: Validate TSC_ADJUST after resume
Message-ID: <20161213132250.GK3124@twins.programming.kicks-ass.net>
References: <20161213131115.764824574@linutronix.de>
 <20161213131211.317654500@linutronix.de>
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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.