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From: Kent Gibson <warthog618@gmail.com>
To: Bartosz Golaszewski <brgl@bgdev.pl>
Cc: Linus Walleij <linus.walleij@linaro.org>,
	linux-gpio@vger.kernel.org, linux-kernel@vger.kernel.org,
	Bartosz Golaszewski <bgolaszewski@baylibre.com>
Subject: Re: [PATCH] gpiolib: fix bitmap operations related to line event watching
Date: Wed, 26 Feb 2020 14:57:33 +0000	[thread overview]
Message-ID: <20200226145733.GA2078@firefly> (raw)
In-Reply-To: <20200226135323.1840-1-brgl@bgdev.pl>

On Wed, Feb 26, 2020 at 02:53:23PM +0100, Bartosz Golaszewski wrote:
> From: Bartosz Golaszewski <bgolaszewski@baylibre.com>
> 
> When operating on the bits of watched_lines bitmap, we're using
> desc_to_gpio() which returns the GPIO number from the global numberspace.
> This leads to all sorts of memory corruptions and invalid behavior. We
> should switch to using gpio_chip_hwgpio() instead.
> 
> Fixes: 51c1064e82e7 ("gpiolib: add new ioctl() for monitoring changes in line info")
> Reported-by: Kent Gibson <warthog618@gmail.com>
> Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>

That fixes all the failures I was seeing.

Tested-by: Kent Gibson <warthog618@gmail.com>

> ---
>  drivers/gpio/gpiolib.c | 6 +++---
>  1 file changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
> index a5cd1b4abe6f..5cc80f6f79e0 100644
> --- a/drivers/gpio/gpiolib.c
> +++ b/drivers/gpio/gpiolib.c
> @@ -1261,7 +1261,7 @@ static long gpio_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
>  			return -EFAULT;
>  
>  		if (cmd == GPIO_GET_LINEINFO_WATCH_IOCTL)
> -			set_bit(desc_to_gpio(desc), priv->watched_lines);
> +			set_bit(gpio_chip_hwgpio(desc), priv->watched_lines);
>  
>  		return 0;
>  	} else if (cmd == GPIO_GET_LINEHANDLE_IOCTL) {
> @@ -1276,7 +1276,7 @@ static long gpio_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
>  		if (IS_ERR(desc))
>  			return PTR_ERR(desc);
>  
> -		clear_bit(desc_to_gpio(desc), priv->watched_lines);
> +		clear_bit(gpio_chip_hwgpio(desc), priv->watched_lines);
>  		return 0;
>  	}
>  	return -EINVAL;
> @@ -1304,7 +1304,7 @@ static int lineinfo_changed_notify(struct notifier_block *nb,
>  	struct gpio_desc *desc = data;
>  	int ret;
>  
> -	if (!test_bit(desc_to_gpio(desc), priv->watched_lines))
> +	if (!test_bit(gpio_chip_hwgpio(desc), priv->watched_lines))
>  		return NOTIFY_DONE;
>  
>  	memset(&chg, 0, sizeof(chg));
> -- 
> 2.25.0
> 

  reply	other threads:[~2020-02-26 14:57 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-02-26 13:53 [PATCH] gpiolib: fix bitmap operations related to line event watching Bartosz Golaszewski
2020-02-26 14:57 ` Kent Gibson [this message]
2020-02-28 23:20 ` Linus Walleij
2020-02-29 13:43   ` Bartosz Golaszewski

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