Re: [PATCH RFC 2/9] aio: Use accessor for hrtimer_sleeper ->task field

"Paul E. McKenney" <[email protected]> Fri, 31 Jul 2026 10:40:44 -0700
Newsgroups gmane.linux.kernel.aio.general,gmane.linux.kernel,gmane.linux.file-systems
Message-ID <0f8ddd97-89e1-45c8-a779-e56adcde4098@paulmck-laptop>
On Fri, Jul 31, 2026 at 02:57:57PM +0200, Christian Brauner wrote:
> On 2026-07-30 17:40 -0700, Paul E. McKenney wrote:
> > The hrtimer_sleeper structure's ->task field is used as a flag to indicate
> > that the associated hrtimer has expired.  This means that the hrtimer
> > handler can be storing to this field while other code is loading from it
> > to check for expiry.  Note that additional races appear for hrtimers that
> > can be restarted, which could be argued to be a user error.  However, that
> > is no reason to let the compiler introduce additional confusion, and to
> > this end, the hrtimer_sleeper_task_get() was introduced, use of which also
> > has the benefit of avoiding open-code access to hrtimer_sleeper innards.
> > 
> > KCSAN located this issue.
> > 
> > Signed-off-by: Paul E. McKenney <[email protected]>
> > Cc: Benjamin LaHaise <[email protected]>
> > Cc: Alexander Viro <[email protected]>
> > Cc: Christian Brauner <[email protected]>
> > Cc: Jan Kara <[email protected]>
> > Cc: Anna-Maria Behnsen <[email protected]>
> > Cc: Frederic Weisbecker <[email protected]>
> > Cc: Thomas Gleixner <[email protected]>
> > Cc: <[email protected]>
> > Cc: <[email protected]>
> > ---
> 
> Reviewed-by: Christian Brauner (Amutable) <[email protected]>

Thank you both, and I will apply your tags on my next rebase.

							Thanx, Paul

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