Re: [PATCH 1/2] gpio: em: remove the gpiochip before removing the irq domain

From: Bartosz Golaszewski
Date: Wed Jul 10 2019 - 05:47:38 EST


År., 10 lip 2019 o 11:37 Phil Reid <preid@xxxxxxxxxxxxxxxxx> napisaÅ(a):
>
> G'day Bartosz,
>
> One comment below
>
> On 10/07/2019 17:08, Bartosz Golaszewski wrote:
> > From: Bartosz Golaszewski <bgolaszewski@xxxxxxxxxxxx>
> >
> > In commit 8764c4ca5049 ("gpio: em: use the managed version of
> > gpiochip_add_data()") we implicitly altered the ordering of resource
> > freeing: since gpiochip_remove() calls gpiochip_irqchip_remove()
> > internally, we now can potentially use the irq_domain after it was
> > destroyed in the remove() callback (as devm resources are freed after
> > remove() has returned).
> >
> > Use devm_add_action() to keep the ordering right and entirely kill
> > the remove() callback in the driver.
> >
> > Reported-by: Geert Uytterhoeven <geert@xxxxxxxxxxxxxx>
> > Fixes: 8764c4ca5049 ("gpio: em: use the managed version of gpiochip_add_data()")
> > Cc: stable@xxxxxxxxxxxxxxx
> > Signed-off-by: Bartosz Golaszewski <bgolaszewski@xxxxxxxxxxxx>
> > ---
> > drivers/gpio/gpio-em.c | 35 +++++++++++++++++------------------
> > 1 file changed, 17 insertions(+), 18 deletions(-)
> >
> > diff --git a/drivers/gpio/gpio-em.c b/drivers/gpio/gpio-em.c
> > index b6af705a4e5f..c88028ac66f2 100644
> > --- a/drivers/gpio/gpio-em.c
> > +++ b/drivers/gpio/gpio-em.c
> > @@ -259,6 +259,13 @@ static const struct irq_domain_ops em_gio_irq_domain_ops = {
> > .xlate = irq_domain_xlate_twocell,
> > };
> >
> > +static void em_gio_irq_domain_remove(void *data)
> > +{
> > + struct irq_domain *domain = data;
> > +
> > + irq_domain_remove(domain);
> > +}
> > +
> > static int em_gio_probe(struct platform_device *pdev)
> > {
> > struct em_gio_priv *p;
> > @@ -333,39 +340,32 @@ static int em_gio_probe(struct platform_device *pdev)
> > return -ENXIO;
> > }
> >
> > + ret = devm_add_action(&pdev->dev,
> > + em_gio_irq_domain_remove, p->irq_domain);
>
> Could devm_add_action_or_reset be used?
>

Of course it could and it should. :)

I'll resend tomorrow to not spam the mailing list.

Thanks,
Bart

> > + if (ret) {
> > + irq_domain_remove(p->irq_domain);
> > + return ret;
> > + }
> > +
> > if (devm_request_irq(&pdev->dev, irq[0]->start,
> > em_gio_irq_handler, 0, name, p)) {
> > dev_err(&pdev->dev, "failed to request low IRQ\n");
> > - ret = -ENOENT;
> > - goto err1;
> > + return -ENOENT;
> > }
> >
> > if (devm_request_irq(&pdev->dev, irq[1]->start,
> > em_gio_irq_handler, 0, name, p)) {
> > dev_err(&pdev->dev, "failed to request high IRQ\n");
> > - ret = -ENOENT;
> > - goto err1;
> > + return -ENOENT;
> > }
> >
> > ret = devm_gpiochip_add_data(&pdev->dev, gpio_chip, p);
> > if (ret) {
> > dev_err(&pdev->dev, "failed to add GPIO controller\n");
> > - goto err1;
> > + return ret;
> > }
> >
> > return 0;
> > -
> > -err1:
> > - irq_domain_remove(p->irq_domain);
> > - return ret;
> > -}
> > -
> > -static int em_gio_remove(struct platform_device *pdev)
> > -{
> > - struct em_gio_priv *p = platform_get_drvdata(pdev);
> > -
> > - irq_domain_remove(p->irq_domain);
> > - return 0;
> > }
> >
> > static const struct of_device_id em_gio_dt_ids[] = {
> > @@ -376,7 +376,6 @@ MODULE_DEVICE_TABLE(of, em_gio_dt_ids);
> >
> > static struct platform_driver em_gio_device_driver = {
> > .probe = em_gio_probe,
> > - .remove = em_gio_remove,
> > .driver = {
> > .name = "em_gio",
> > .of_match_table = em_gio_dt_ids,
> >
>
>
> --
> Regards
> Phil Reid
>