Re: [PATCH 3/3] intr: Protect internals with a lock

[Samuel Thibault]

Sergey Bugaev, le mar. 10 déc. 2024 15:24:02 +0300, a ecrit:
> On Tue, Dec 10, 2024 at 3:19 PM Samuel Thibault <samuel.thibault@gnu.org> 
> wrote:
> > Sergey Bugaev, le mar. 10 déc. 2024 14:57:05 +0300, a ecrit:
> > > @@ -103,11 +105,15 @@ queue_intr (struct irqdev *dev, int id, user_intr_t 
> > > *e)
> > >     * disabled. Level-triggered interrupts would keep raising otherwise. 
> > > */
> > >    __disable_irq (dev->irq[id]);
> > >
> > > -  spl_t s = splhigh ();
> > > +#ifdef LINUX_DEV
> > > +  spl_t s = simple_lock_irq(&intr_lock);
> > > +#endif
> >
> > Why only ifdef LINUX_DEV? AIUI We do want to always lock.
> 
> As said, I'm not sure if that's the correct thing. But the reasoning
> here has been that deliver_user_intr (which is what calls queue_intr)
> is called from two different contexts:

Ah, right.

This definitely deserves a comment saying that locking is already done
in user_irq_handler in the !LINUX_DEV case.

Samuel