Re: [PATCH] alarmtimer: Do not mess with an enqueued hrtimer

[Thomas Gleixner]

On Thu, Jan 07 2021 at 13:33, Li RongQing wrote:
> when an hrtimer is enqueued already, its expires should be not
> changed, otherwise, this will corrupts the ordering of the
> timerqueue RB tree, if other hrtimer is enqueued before this
> hrtimer is restarted, whole RB tree is completely hosed
>
> Fixes: 6cffe00f7d4e ("alarmtimer: Add functions for timerfd support")

I can't see what this fixes. alarm_restart() is only invoked when the
alarm has expired which means that the timer _cannot_ be queued.

Thanks,

        tglx