[v2,1/2] gpio: em: remove the gpiochip before removing the irq domain
diff mbox series

Message ID 20190711082936.8706-1-brgl@bgdev.pl
State New
Headers show
Series
  • [v2,1/2] gpio: em: remove the gpiochip before removing the irq domain
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Commit Message

Bartosz Golaszewski July 11, 2019, 8:29 a.m. UTC
From: Bartosz Golaszewski <bgolaszewski@baylibre.com>

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_or_reset() to keep the ordering right and entirely
kill the remove() callback in the driver.

Reported-by: Geert Uytterhoeven <geert@linux-m68k.org>
Fixes: 8764c4ca5049 ("gpio: em: use the managed version of gpiochip_add_data()")
Cc: stable@vger.kernel.org
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
---
v1 -> v2:
- use devm_add_action_or_reset() to automatically remove the domain if
  the underlying devm_add_action() fails

 drivers/gpio/gpio-em.c | 33 +++++++++++++++------------------
 1 file changed, 15 insertions(+), 18 deletions(-)

Comments

Geert Uytterhoeven July 11, 2019, 8:46 a.m. UTC | #1
CC Niklas, who has the hardware

On Thu, Jul 11, 2019 at 10:29 AM Bartosz Golaszewski <brgl@bgdev.pl> wrote:
> From: Bartosz Golaszewski <bgolaszewski@baylibre.com>
>
> 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_or_reset() to keep the ordering right and entirely
> kill the remove() callback in the driver.
>
> Reported-by: Geert Uytterhoeven <geert@linux-m68k.org>
> Fixes: 8764c4ca5049 ("gpio: em: use the managed version of gpiochip_add_data()")
> Cc: stable@vger.kernel.org
> Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>

Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>

Gr{oetje,eeting}s,

                        Geert
Bartosz Golaszewski July 15, 2019, 9:58 a.m. UTC | #2
czw., 11 lip 2019 o 10:47 Geert Uytterhoeven <geert@linux-m68k.org> napisaƂ(a):
>
> CC Niklas, who has the hardware
>
> On Thu, Jul 11, 2019 at 10:29 AM Bartosz Golaszewski <brgl@bgdev.pl> wrote:
> > From: Bartosz Golaszewski <bgolaszewski@baylibre.com>
> >
> > 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_or_reset() to keep the ordering right and entirely
> > kill the remove() callback in the driver.
> >
> > Reported-by: Geert Uytterhoeven <geert@linux-m68k.org>
> > Fixes: 8764c4ca5049 ("gpio: em: use the managed version of gpiochip_add_data()")
> > Cc: stable@vger.kernel.org
> > Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
>
> Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
>
> Gr{oetje,eeting}s,
>
>                         Geert
>
> --
> Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org
>
> In personal conversations with technical people, I call myself a hacker. But
> when I'm talking to journalists I just say "programmer" or something like that.
>                                 -- Linus Torvalds

Patch applied.

Patch
diff mbox series

diff --git a/drivers/gpio/gpio-em.c b/drivers/gpio/gpio-em.c
index b6af705a4e5f..a87951293aaa 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 +340,30 @@  static int em_gio_probe(struct platform_device *pdev)
 		return -ENXIO;
 	}
 
+	ret = devm_add_action_or_reset(&pdev->dev, em_gio_irq_domain_remove,
+				       p->irq_domain);
+	if (ret)
+		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 +374,6 @@  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,