Re: [PATCH] time, ntp: Do not update time_state in middle of leap second

From: Peter Zijlstra
Date: Tue Feb 10 2015 - 09:02:07 EST

On Sat, Feb 07, 2015 at 01:29:39PM -0500, Prarit Bhargava wrote:
> During leap second insertion testing it was noticed that a small window
> exists where the time_state could be reset such that
> time_state = TIME_OK, which then causes the leap second to not occur, or
> causes the entire leap second state machine to fail.
> While this is highly unlikely to ever happen in the real world it is
> still something we should protect against, as breaking the state machine
> is obviously bad.
> If the time_state == TIME_OOP (ie, the leap second is in progress) do not
> allow an external update to time_state.
> [v2]: Only block time_state change when TIME_OOP
> Signed-off-by: Prarit Bhargava <prarit@xxxxxxxxxx>
> Cc: John Stultz <john.stultz@xxxxxxxxxx>
> Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
> Cc: Miroslav Lichvar <mlichvar@xxxxxxxxxx>

John, ACK?
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