gpio: tb10x: Fix an error handling path in tb10x_gpio_probe()

[PATCH] gpio: tb10x: Fix an error handling path in tb10x_gpio_probe()

Posted by Christophe JAILLET 2 years, 3 months ago

If an error occurs after a successful irq_domain_add_linear() call, it
should be undone by a corresponding irq_domain_remove(), as already done
in the remove function.

Fixes: c6ce2b6bffe5 ("gpio: add TB10x GPIO driver")
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
---
 drivers/gpio/gpio-tb10x.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/gpio/gpio-tb10x.c b/drivers/gpio/gpio-tb10x.c
index 78f8790168ae..f96d260a4a19 100644
--- a/drivers/gpio/gpio-tb10x.c
+++ b/drivers/gpio/gpio-tb10x.c
@@ -195,7 +195,7 @@ static int tb10x_gpio_probe(struct platform_device *pdev)
 				handle_edge_irq, IRQ_NOREQUEST, IRQ_NOPROBE,
 				IRQ_GC_INIT_MASK_CACHE);
 		if (ret)
-			return ret;
+			goto err_remove_domain;
 
 		gc = tb10x_gpio->domain->gc->gc[0];
 		gc->reg_base                         = tb10x_gpio->base;
@@ -209,6 +209,10 @@ static int tb10x_gpio_probe(struct platform_device *pdev)
 	}
 
 	return 0;
+
+err_remove_domain:
+	irq_domain_remove(tb10x_gpio->domain);
+	return ret;
 }
 
 static int tb10x_gpio_remove(struct platform_device *pdev)
-- 
2.34.1

Re: [PATCH] gpio: tb10x: Fix an error handling path in tb10x_gpio_probe()

Posted by Bartosz Golaszewski 2 years, 3 months ago

On Sun, Sep 3, 2023 at 8:13 AM Christophe JAILLET
<christophe.jaillet@wanadoo.fr> wrote:
>
> If an error occurs after a successful irq_domain_add_linear() call, it
> should be undone by a corresponding irq_domain_remove(), as already done
> in the remove function.
>
> Fixes: c6ce2b6bffe5 ("gpio: add TB10x GPIO driver")
> Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
> ---
>  drivers/gpio/gpio-tb10x.c | 6 +++++-
>  1 file changed, 5 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/gpio/gpio-tb10x.c b/drivers/gpio/gpio-tb10x.c
> index 78f8790168ae..f96d260a4a19 100644
> --- a/drivers/gpio/gpio-tb10x.c
> +++ b/drivers/gpio/gpio-tb10x.c
> @@ -195,7 +195,7 @@ static int tb10x_gpio_probe(struct platform_device *pdev)
>                                 handle_edge_irq, IRQ_NOREQUEST, IRQ_NOPROBE,
>                                 IRQ_GC_INIT_MASK_CACHE);
>                 if (ret)
> -                       return ret;
> +                       goto err_remove_domain;
>
>                 gc = tb10x_gpio->domain->gc->gc[0];
>                 gc->reg_base                         = tb10x_gpio->base;
> @@ -209,6 +209,10 @@ static int tb10x_gpio_probe(struct platform_device *pdev)
>         }
>
>         return 0;
> +
> +err_remove_domain:
> +       irq_domain_remove(tb10x_gpio->domain);
> +       return ret;
>  }
>
>  static int tb10x_gpio_remove(struct platform_device *pdev)
> --
> 2.34.1
>

That's not enough, you also need to dispose of all remaining mappings.
Please see drivers/gpio/gpiolib.c and how it handles the gpio_irq_chip
domain.

Bartosz

Re: [PATCH] gpio: tb10x: Fix an error handling path in tb10x_gpio_probe()

Posted by Christophe JAILLET 2 years, 3 months ago

Le 03/09/2023 à 19:02, Bartosz Golaszewski a écrit :
> On Sun, Sep 3, 2023 at 8:13 AM Christophe JAILLET
> <christophe.jaillet@wanadoo.fr> wrote:
>>
>> If an error occurs after a successful irq_domain_add_linear() call, it
>> should be undone by a corresponding irq_domain_remove(), as already done
>> in the remove function.
>>
>> Fixes: c6ce2b6bffe5 ("gpio: add TB10x GPIO driver")
>> Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
>> ---
>>   drivers/gpio/gpio-tb10x.c | 6 +++++-
>>   1 file changed, 5 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/gpio/gpio-tb10x.c b/drivers/gpio/gpio-tb10x.c
>> index 78f8790168ae..f96d260a4a19 100644
>> --- a/drivers/gpio/gpio-tb10x.c
>> +++ b/drivers/gpio/gpio-tb10x.c
>> @@ -195,7 +195,7 @@ static int tb10x_gpio_probe(struct platform_device *pdev)
>>                                  handle_edge_irq, IRQ_NOREQUEST, IRQ_NOPROBE,
>>                                  IRQ_GC_INIT_MASK_CACHE);
>>                  if (ret)
>> -                       return ret;
>> +                       goto err_remove_domain;
>>
>>                  gc = tb10x_gpio->domain->gc->gc[0];
>>                  gc->reg_base                         = tb10x_gpio->base;
>> @@ -209,6 +209,10 @@ static int tb10x_gpio_probe(struct platform_device *pdev)
>>          }
>>
>>          return 0;
>> +
>> +err_remove_domain:
>> +       irq_domain_remove(tb10x_gpio->domain);
>> +       return ret;
>>   }
>>
>>   static int tb10x_gpio_remove(struct platform_device *pdev)
>> --
>> 2.34.1
>>
> 
> That's not enough, you also need to dispose of all remaining mappings.
> Please see drivers/gpio/gpiolib.c and how it handles the gpio_irq_chip
> domain.

Hi,

you'll have to give me more explanation because I've not been able to 
find anything useful to me.

CJ

> 
> Bartosz
>

Re: [PATCH] gpio: tb10x: Fix an error handling path in tb10x_gpio_probe()

Posted by Bartosz Golaszewski 2 years, 3 months ago

On Sat, Sep 16, 2023 at 5:10 PM Christophe JAILLET
<christophe.jaillet@wanadoo.fr> wrote:
>
> Le 03/09/2023 à 19:02, Bartosz Golaszewski a écrit :
> > On Sun, Sep 3, 2023 at 8:13 AM Christophe JAILLET
> > <christophe.jaillet@wanadoo.fr> wrote:
> >>
> >> If an error occurs after a successful irq_domain_add_linear() call, it
> >> should be undone by a corresponding irq_domain_remove(), as already done
> >> in the remove function.
> >>
> >> Fixes: c6ce2b6bffe5 ("gpio: add TB10x GPIO driver")
> >> Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
> >> ---
> >>   drivers/gpio/gpio-tb10x.c | 6 +++++-
> >>   1 file changed, 5 insertions(+), 1 deletion(-)
> >>
> >> diff --git a/drivers/gpio/gpio-tb10x.c b/drivers/gpio/gpio-tb10x.c
> >> index 78f8790168ae..f96d260a4a19 100644
> >> --- a/drivers/gpio/gpio-tb10x.c
> >> +++ b/drivers/gpio/gpio-tb10x.c
> >> @@ -195,7 +195,7 @@ static int tb10x_gpio_probe(struct platform_device *pdev)
> >>                                  handle_edge_irq, IRQ_NOREQUEST, IRQ_NOPROBE,
> >>                                  IRQ_GC_INIT_MASK_CACHE);
> >>                  if (ret)
> >> -                       return ret;
> >> +                       goto err_remove_domain;
> >>
> >>                  gc = tb10x_gpio->domain->gc->gc[0];
> >>                  gc->reg_base                         = tb10x_gpio->base;
> >> @@ -209,6 +209,10 @@ static int tb10x_gpio_probe(struct platform_device *pdev)
> >>          }
> >>
> >>          return 0;
> >> +
> >> +err_remove_domain:
> >> +       irq_domain_remove(tb10x_gpio->domain);
> >> +       return ret;
> >>   }
> >>
> >>   static int tb10x_gpio_remove(struct platform_device *pdev)
> >> --
> >> 2.34.1
> >>
> >
> > That's not enough, you also need to dispose of all remaining mappings.
> > Please see drivers/gpio/gpiolib.c and how it handles the gpio_irq_chip
> > domain.
>
> Hi,
>
> you'll have to give me more explanation because I've not been able to
> find anything useful to me.
>

I should have expressed myself clearer. Your patch is correct and I
will queue it. But in your remove callback, you'll need to go through
the existing irq mappings and dispose of them before returning. Please
see gpiochip_irqchip_remove()[1]. You can send it as a follow-up.

Bart

[1] https://elixir.bootlin.com/linux/latest/source/drivers/gpio/gpiolib.c#L1725