[PATCH 1/6] gpio: fix memory and reference leaks in gpiochip_add error path

[PATCH 1/6] gpio: fix memory and reference leaks in gpiochip_add error path

[Johan Hovold]

Memory allocated and references taken by of_gpiochip_add and
acpi_gpiochip_add were never released on errors in gpiochip_add (e.g.
failure to find free gpio range).

Fixes: 391c970c0dd1 ("of/gpio: add default of_xlate function if device
has a node pointer")
Fixes: 664e3e5ac64c ("gpio / ACPI: register to ACPI events
automatically")
Cc: stable <stable@vger.kernel.org>

Signed-off-by: Johan Hovold <johan@kernel.org>
---
 drivers/gpio/gpiolib.c | 11 +++++++----
 1 file changed, 7 insertions(+), 4 deletions(-)

diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index 487afe6f22fc..89c59f5f1924 100644
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -277,6 +277,9 @@ int gpiochip_add(struct gpio_chip *chip)
 
 	spin_unlock_irqrestore(&gpio_lock, flags);
 
+	if (status)
+		goto fail;
+
 #ifdef CONFIG_PINCTRL
 	INIT_LIST_HEAD(&chip->pin_ranges);
 #endif
@@ -284,12 +287,12 @@ int gpiochip_add(struct gpio_chip *chip)
 	of_gpiochip_add(chip);
 	acpi_gpiochip_add(chip);
 
-	if (status)
-		goto fail;
-
 	status = gpiochip_export(chip);
-	if (status)
+	if (status) {
+		acpi_gpiochip_remove(chip);
+		of_gpiochip_remove(chip);
 		goto fail;
+	}
 
 	pr_debug("%s: registered GPIOs %d to %d on device: %s\n", __func__,
 		chip->base, chip->base + chip->ngpio - 1,
-- 
2.0.5

[PATCH 4/6] gpio: fix memory leak and sleep-while-atomic

[Johan Hovold]

Fix memory leak and sleep-while-atomic in gpiochip_remove.

The memory leak was introduced by afa82fab5e13 ("gpio / ACPI: Move event
handling registration to gpiolib irqchip helpers") that moved the
release of acpi interrupt resources to gpiochip_irqchip_remove, but by
then the resources are no longer accessible as the acpi_gpio_chip has
already been freed by acpi_gpiochip_remove.

Note that this also fixes a few potential sleep-while-atomics, which has
been around since 1425052097b5 ("gpio: add IRQ chip helpers in gpiolib")
when the call to gpiochip_irqchip_remove while holding a spinlock was
added (a couple of irq-domain paths can end up grabbing mutexes).

Fixes: afa82fab5e13 ("gpio / ACPI: Move event handling registration to
gpiolib irqchip helpers")
Fixes: 1425052097b5 ("gpio: add IRQ chip helpers in gpiolib")
Cc: stable <stable@vger.kernel.org>

Signed-off-by: Johan Hovold <johan@kernel.org>
---
 drivers/gpio/gpiolib.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index 4efb92ca3463..0f8173051edc 100644
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -327,11 +327,12 @@ void gpiochip_remove(struct gpio_chip *chip)
 	unsigned long	flags;
 	unsigned	id;
 
+	gpiochip_irqchip_remove(chip);
+
 	acpi_gpiochip_remove(chip);
 
 	spin_lock_irqsave(&gpio_lock, flags);
 
-	gpiochip_irqchip_remove(chip);
 	gpiochip_remove_pin_ranges(chip);
 	of_gpiochip_remove(chip);
 
-- 
2.0.5

[PATCH 5/6] gpio: fix sleep-while-atomic in gpiochip_remove

[Johan Hovold]

Move direct and indirect calls to gpiochip_remove_pin_ranges outside of
spin lock as they can end up taking a mutex in pinctrl_remove_gpio_range.

Note that the pin ranges are already added outside of the lock.

Fixes: 9ef0d6f7628b ("gpiolib: call pin removal in chip removal function")
Fixes: f23f1516b675 ("gpiolib: provide provision to register pin ranges")
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Johan Hovold <johan@kernel.org>
---
 drivers/gpio/gpiolib.c | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index 0f8173051edc..37f919dc2cb4 100644
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -330,12 +330,10 @@ void gpiochip_remove(struct gpio_chip *chip)
 	gpiochip_irqchip_remove(chip);
 
 	acpi_gpiochip_remove(chip);
-
-	spin_lock_irqsave(&gpio_lock, flags);
-
 	gpiochip_remove_pin_ranges(chip);
 	of_gpiochip_remove(chip);
 
+	spin_lock_irqsave(&gpio_lock, flags);
 	for (id = 0; id < chip->ngpio; id++) {
 		if (test_bit(FLAG_REQUESTED, &chip->desc[id].flags))
 			dev_crit(chip->dev, "REMOVING GPIOCHIP WITH GPIOS STILL REQUESTED\n");
-- 
2.0.5