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Date:   Thu, 9 Jun 2022 12:50:13 +0200
From:   Peter Zijlstra <peterz@infradead.org>
To:     Frederic Weisbecker <frederic@kernel.org>
Cc:     LKML <linux-kernel@vger.kernel.org>, Phil Auld <pauld@redhat.com>,
        Alex Belits <abelits@marvell.com>,
        Nicolas Saenz Julienne <nsaenz@kernel.org>,
        Xiongfeng Wang <wangxiongfeng2@huawei.com>,
        Neeraj Upadhyay <quic_neeraju@quicinc.com>,
        Thomas Gleixner <tglx@linutronix.de>,
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        Boqun Feng <boqun.feng@gmail.com>,
        "Paul E . McKenney" <paulmck@kernel.org>,
        Marcelo Tosatti <mtosatti@redhat.com>,
        Paul Gortmaker <paul.gortmaker@windriver.com>,
        Uladzislau Rezki <uladzislau.rezki@sony.com>,
        Joel Fernandes <joel@joelfernandes.org>
Subject: Re: [PATCH 02/20] context_tracking: Add a note about noinstr VS
 unsafe context tracking functions
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References: <20220608144037.1765000-1-frederic@kernel.org>
 <20220608144037.1765000-3-frederic@kernel.org>
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On Wed, Jun 08, 2022 at 04:40:19PM +0200, Frederic Weisbecker wrote:
> +/*
> + * OBSOLETE:
> + * This function should be noinstr but the below local_irq_restore() is
> + * unsafe because it involves illegal RCU uses through tracing and lockdep.
> + * This is unlikely to be fixed as this function is obsolete. The preferred
> + * way is to call __context_tracking_enter() through user_enter_irqoff()
> + * or context_tracking_guest_enter(). It should be the arch entry code
> + * responsibility to call into context tracking with IRQs disabled.
> +
> + */

whitespace fail there, methinks.

>  void context_tracking_enter(enum ctx_state state)
>  {
>  	unsigned long flags;