Re: [PATCH 1/4] genirq/irq_sim: dispose of remaining mappings before removing the domain

[Bartosz Golaszewski]

On Tue, Aug 15, 2023 at 12:38 PM Andy Shevchenko
<andriy.shevchenko@xxxxxxxxxxxxxxx> wrote:
>
> On Sat, Aug 12, 2023 at 09:44:54PM +0200, Bartosz Golaszewski wrote:
> > From: Bartosz Golaszewski <bartosz.golaszewski@xxxxxxxxxx>
> >
> > If the device providing simulated interrupts is unbound (real life
> > example: gpio-sim is disabled with users that didn't free their irqs)
> > and removes the simulated domain while interrupts are still requested,
> > we will hit memory issues when they are eventually freed and the
> > mappings destroyed in the process.
> >
> > Specifically we'll access freed memory in __irq_domain_deactivate_irq().
> >
> > Dispose of all mappings before removing the simulator domain.
>
> ...
>
> > +#include <linux/list.h>
>
> Maybe ordered?
>

This patch comes first in the series as it's meant to be a
backportable fix. Header ordering comes later.

Bart

> >  #include <linux/irq.h>
> >  #include <linux/irq_sim.h>
> >  #include <linux/irq_work.h>
>
> ...
>
> > @@ -16,12 +17,14 @@ struct irq_sim_work_ctx {
> >       unsigned int            irq_count;
> >       unsigned long           *pending;
> >       struct irq_domain       *domain;
> > +     struct list_head        irqs;
> >  };
> >
> >  struct irq_sim_irq_ctx {
> >       int                     irqnum;
> >       bool                    enabled;
> >       struct irq_sim_work_ctx *work_ctx;
>
> > +     struct list_head        siblings;
>
> You can reduce the code size by moving this to be the first member.
> Not sure about struct irq_sim_work_ctx, you can play with bloat-o-meter.
>
> >  };
>
> --
> With Best Regards,
> Andy Shevchenko
>
>