Re: [PATCH 2/2] gpio: fix gpio-device list corruption

2021-02-26 Thread Saravana Kannan
On Fri, Feb 26, 2021 at 6:55 AM Johan Hovold  wrote:
>
> Make sure to hold the gpio_lock when removing the gpio device from the
> gpio_devices list (when dropping the last reference) to avoid corrupting
> the list when there are concurrent accesses.
>
> Fixes: ff2b13592299 ("gpio: make the gpiochip a real device")
> Cc: sta...@vger.kernel.org  # 4.6
> Signed-off-by: Johan Hovold 
> ---
>  drivers/gpio/gpiolib.c | 4 
>  1 file changed, 4 insertions(+)
>
> diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
> index e1016bc8cf14..42bdc55a15f9 100644
> --- a/drivers/gpio/gpiolib.c
> +++ b/drivers/gpio/gpiolib.c
> @@ -475,8 +475,12 @@ EXPORT_SYMBOL_GPL(gpiochip_line_is_valid);
>  static void gpiodevice_release(struct device *dev)
>  {
> struct gpio_device *gdev = container_of(dev, struct gpio_device, dev);
> +   unsigned long flags;
>
> +   spin_lock_irqsave(_lock, flags);
> list_del(>list);
> +   spin_unlock_irqrestore(_lock, flags);
> +

Reviewed-by: Saravana Kannan 

-Saravana

> ida_free(_ida, gdev->id);
> kfree_const(gdev->label);
> kfree(gdev->descs);
> --
> 2.26.2
>


[PATCH 2/2] gpio: fix gpio-device list corruption

2021-02-26 Thread Johan Hovold
Make sure to hold the gpio_lock when removing the gpio device from the
gpio_devices list (when dropping the last reference) to avoid corrupting
the list when there are concurrent accesses.

Fixes: ff2b13592299 ("gpio: make the gpiochip a real device")
Cc: sta...@vger.kernel.org  # 4.6
Signed-off-by: Johan Hovold 
---
 drivers/gpio/gpiolib.c | 4 
 1 file changed, 4 insertions(+)

diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index e1016bc8cf14..42bdc55a15f9 100644
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -475,8 +475,12 @@ EXPORT_SYMBOL_GPL(gpiochip_line_is_valid);
 static void gpiodevice_release(struct device *dev)
 {
struct gpio_device *gdev = container_of(dev, struct gpio_device, dev);
+   unsigned long flags;
 
+   spin_lock_irqsave(_lock, flags);
list_del(>list);
+   spin_unlock_irqrestore(_lock, flags);
+
ida_free(_ida, gdev->id);
kfree_const(gdev->label);
kfree(gdev->descs);
-- 
2.26.2