Re: [PATCH v2 1/4] gpio: virtuser: fix missing lookup table cleanups

[Koichiro Den <koichiro.den@xxxxxxxxxxxxx>]

On Fri, Jan 03, 2025 at 02:15:17PM +0100, Bartosz Golaszewski wrote:
> On Fri, Jan 3, 2025 at 4:04 AM Koichiro Den <koichiro.den@xxxxxxxxxxxxx> wrote:
> >
> > When a virtuser device is created via configfs and the probe fails due
> > to an incorrect lookup table, the table is not removed. This prevents
> > subsequent probe attempts from succeeding, even if the issue is
> > corrected, unless the device is released. Additionally, cleanup is also
> > needed in the less likely case of platform_device_register_full()
> > failure.
> >
> > Ensure the lookup table is removed whenever the device activation fails.
> >
> > Fixes: 91581c4b3f29 ("gpio: virtuser: new virtual testing driver for the GPIO API")
> > Signed-off-by: Koichiro Den <koichiro.den@xxxxxxxxxxxxx>
> > ---
> >  drivers/gpio/gpio-virtuser.c | 25 ++++++++++++++++---------
> >  1 file changed, 16 insertions(+), 9 deletions(-)
> >
> > diff --git a/drivers/gpio/gpio-virtuser.c b/drivers/gpio/gpio-virtuser.c
> > index 91b6352c957c..ec5abfebca3d 100644
> > --- a/drivers/gpio/gpio-virtuser.c
> > +++ b/drivers/gpio/gpio-virtuser.c
> > @@ -1487,10 +1487,8 @@ gpio_virtuser_device_activate(struct gpio_virtuser_device *dev)
> >         pdevinfo.fwnode = swnode;
> >
> >         ret = gpio_virtuser_make_lookup_table(dev);
> > -       if (ret) {
> > -               fwnode_remove_software_node(swnode);
> > -               return ret;
> > -       }
> > +       if (ret)
> > +               goto err_remove_swnode;
> >
> >         reinit_completion(&dev->probe_completion);
> >         dev->driver_bound = false;
> > @@ -1498,23 +1496,32 @@ gpio_virtuser_device_activate(struct gpio_virtuser_device *dev)
> >
> >         pdev = platform_device_register_full(&pdevinfo);
> >         if (IS_ERR(pdev)) {
> > +               ret = PTR_ERR(pdev);
> >                 bus_unregister_notifier(&platform_bus_type, &dev->bus_notifier);
> > -               fwnode_remove_software_node(swnode);
> > -               return PTR_ERR(pdev);
> > +               goto err_remove_lookup_table;
> >         }
> >
> >         wait_for_completion(&dev->probe_completion);
> >         bus_unregister_notifier(&platform_bus_type, &dev->bus_notifier);
> >
> >         if (!dev->driver_bound) {
> > -               platform_device_unregister(pdev);
> > -               fwnode_remove_software_node(swnode);
> > -               return -ENXIO;
> > +               ret = -ENXIO;
> > +               goto err_unregister_pdev;
> >         }
> >
> >         dev->pdev = pdev;
> >
> >         return 0;
> > +
> > +err_unregister_pdev:
> > +       platform_device_unregister(pdev);
> > +err_remove_lookup_table:
> > +       gpiod_remove_lookup_table(dev->lookup_table);
> > +       kfree(dev->lookup_table);
> 
> Just one more thing: now we open-code this but the actual allocation
> and adding of the table happens in a dedicated function. Can you
> package these calls into their own function
> (gpio_virtuser_remove_lookup_table() maybe?) and use it here and in
> gpio_virtuser_device_deactivate()?

Sounds reasonable and cleaner. Thanks again for reviewing, I'll send v3
soon.

-Koichiro

> 
> Bart
> 
> > +err_remove_swnode:
> > +       fwnode_remove_software_node(swnode);
> > +
> > +       return ret;
> >  }
> >
> >  static void
> > --
> > 2.43.0
> >