[PATCH 5.10 79/80] gpio: tegra186: Fix chip_data type confusion

Greg Kroah-Hartman
2022-02-28T17:46:34Z

From: Marc Zyngier <maz@kernel.org>

commit d1e972ace42390de739cde87d96043dcbe502286 upstream.

The tegra186 GPIO driver makes the assumption that the pointer
returned by irq_data_get_irq_chip_data() is a pointer to a
tegra_gpio structure. Unfortunately, it is actually a pointer
to the inner gpio_chip structure, as mandated by the gpiolib
infrastructure. Nice try.

The saving grace is that the gpio_chip is the first member of
tegra_gpio, so the bug has gone undetected since... forever.

Fix it by performing a container_of() on the pointer. This results
in no additional code, and makes it possible to understand how
the whole thing works.

Fixes: 5b2b135a87fc ("gpio: Add Tegra186 support")
Signed-off-by: Marc Zyngier <maz@kernel.org>
Cc: Thierry Reding <treding@nvidia.com>
Cc: Linus Walleij <linus.walleij@linaro.org>
Cc: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Link: https://lore.kernel.org/r/20220211093904.1112679-1-maz@kernel.org
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/gpio/gpio-tegra186.c | 14 ++++++++++----
1 file changed, 10 insertions(+), 4 deletions(-)

--- a/drivers/gpio/gpio-tegra186.c
+++ b/drivers/gpio/gpio-tegra186.c
@@ -337,9 +337,12 @@ static int tegra186_gpio_of_xlate(struct
return offset + pin;
}

+#define to_tegra_gpio(x) container_of((x), struct tegra_gpio, gpio)
+
static void tegra186_irq_ack(struct irq_data *data)
{
- struct tegra_gpio *gpio = irq_data_get_irq_chip_data(data);
+ struct gpio_chip *gc = irq_data_get_irq_chip_data(data);
+ struct tegra_gpio *gpio = to_tegra_gpio(gc);
void __iomem *base;

base = tegra186_gpio_get_base(gpio, data->hwirq);
@@ -351,7 +354,8 @@ static void tegra186_irq_ack(struct irq_

static void tegra186_irq_mask(struct irq_data *data)
{
- struct tegra_gpio *gpio = irq_data_get_irq_chip_data(data);
+ struct gpio_chip *gc = irq_data_get_irq_chip_data(data);
+ struct tegra_gpio *gpio = to_tegra_gpio(gc);
void __iomem *base;
u32 value;

@@ -366,7 +370,8 @@ static void tegra186_irq_mask(struct irq

static void tegra186_irq_unmask(struct irq_data *data)
{
- struct tegra_gpio *gpio = irq_data_get_irq_chip_data(data);
+ struct gpio_chip *gc = irq_data_get_irq_chip_data(data);
+ struct tegra_gpio *gpio = to_tegra_gpio(gc);
void __iomem *base;
u32 value;

@@ -381,7 +386,8 @@ static void tegra186_irq_unmask(struct i

static int tegra186_irq_set_type(struct irq_data *data, unsigned int type)
{
- struct tegra_gpio *gpio = irq_data_get_irq_chip_data(data);
+ struct gpio_chip *gc = irq_data_get_irq_chip_data(data);
+ struct tegra_gpio *gpio = to_tegra_gpio(gc);
void __iomem *base;
u32 value;