[PATCH v2] pinctrl-exynos5440: Use off-stack memory for pinctrl_gpio_range

[Andrew Jeffery <andrew@aj.id.au>]

The range is registered into a linked list which can be referenced
throughout the lifetime of the driver. Ensure the range's memory is useful
for the same lifetime by adding it to the driver's private data structure.

The bug was introduced in the driver's initial commit, which was present in
v3.10.

Signed-off-by: Andrew Jeffery <andrew@aj.id.au>
Fixes: f0b9a7e521fa ("pinctrl: exynos5440: add pinctrl driver for Samsung EXYNOS5440 SoC")
Cc: stable@vger.kernel.org
---
Since v1:

* Add range member kerneldoc addressing Tomasz Figa's comment

This is my first contribution to the kernel, so hopefully I've followed all the
relevant documentation. If not, please let me know and point me in the right
direction!

I don't have the means to test the patch, but it compiles. Someone with
appropriate hardware should probably give it a spin. From the responses it
seems that few might have access, and given the nature of the bug it might be
the case that no-one has complained because no-one is affected - is it worth
maintaining going forward?

 drivers/pinctrl/samsung/pinctrl-exynos5440.c | 15 ++++++++-------
 1 file changed, 8 insertions(+), 7 deletions(-)

diff --git a/drivers/pinctrl/samsung/pinctrl-exynos5440.c b/drivers/pinctrl/samsung/pinctrl-exynos5440.c
index 00ab63abf1d9..dbbdf652c34a 100644
--- a/drivers/pinctrl/samsung/pinctrl-exynos5440.c
+++ b/drivers/pinctrl/samsung/pinctrl-exynos5440.c
@@ -107,6 +107,7 @@ struct exynos5440_pmx_func {
  * @nr_groups: number of pin groups available.
  * @pmx_functions: list of pin functions parsed from device tree.
  * @nr_functions: number of pin functions available.
+ * @range: gpio range to register with pinctrl
  */
 struct exynos5440_pinctrl_priv_data {
 	void __iomem			*reg_base;
@@ -117,6 +118,7 @@ struct exynos5440_pinctrl_priv_data {
 	unsigned int			nr_groups;
 	const struct exynos5440_pmx_func	*pmx_functions;
 	unsigned int			nr_functions;
+	struct pinctrl_gpio_range	range;
 };
 
 /**
@@ -742,7 +744,6 @@ static int exynos5440_pinctrl_register(struct platform_device *pdev,
 	struct pinctrl_desc *ctrldesc;
 	struct pinctrl_dev *pctl_dev;
 	struct pinctrl_pin_desc *pindesc, *pdesc;
-	struct pinctrl_gpio_range grange;
 	char *pin_names;
 	int pin, ret;
 
@@ -794,12 +795,12 @@ static int exynos5440_pinctrl_register(struct platform_device *pdev,
 		return PTR_ERR(pctl_dev);
 	}
 
-	grange.name = "exynos5440-pctrl-gpio-range";
-	grange.id = 0;
-	grange.base = 0;
-	grange.npins = EXYNOS5440_MAX_PINS;
-	grange.gc = priv->gc;
-	pinctrl_add_gpio_range(pctl_dev, &grange);
+	priv->range.name = "exynos5440-pctrl-gpio-range";
+	priv->range.id = 0;
+	priv->range.base = 0;
+	priv->range.npins = EXYNOS5440_MAX_PINS;
+	priv->range.gc = priv->gc;
+	pinctrl_add_gpio_range(pctl_dev, &priv->range);
 	return 0;
 }
 
-- 
2.5.0