Received-SPF: pass (google.com: domain of linux-kernel+bounces-92501-linux.lists.archive=gmail.com@vger.kernel.org designates 147.75.199.223 as permitted sender) client-ip=147.75.199.223;
Date: Tue, 5 Mar 2024 17:14:33 +0300
From: Dan Carpenter <dan.carpenter@linaro.org>
To: Charles Keepax <ckeepax@opensource.cirrus.com>
Cc: linus.walleij@linaro.org, brgl@bgdev.pl, linux-gpio@vger.kernel.org,
	linux-kernel@vger.kernel.org, patches@opensource.cirrus.com
Subject: Re: [PATCH] gpio: swnode: Don't use __free() on result of
 swnode_get_gpio_device()
Message-ID: <cbb40800-d01a-4e3b-bf36-6cfcb85b2796@moroto.mountain>
References: <20240304160320.1054811-1-ckeepax@opensource.cirrus.com>
Precedence: bulk
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <20240304160320.1054811-1-ckeepax@opensource.cirrus.com>

On Mon, Mar 04, 2024 at 04:03:20PM +0000, Charles Keepax wrote:
> swnode_get_gpio_device() can return an error pointer, however
> gpio_device_put() is not able to accept error values. Thus using
> __free() will result in dereferencing an invalid pointer.
> 

No, this code works as-is.  The gpio_device_put() won't be called
directly, it will be called by a wrapper that checks for error pointers.
The __free() stuff is defined like this:

include/linux/gpio/driver.h
   655  DEFINE_FREE(gpio_device_put, struct gpio_device *,
   656              if (!IS_ERR_OR_NULL(_T)) gpio_device_put(_T))

So it handles error pointers correctly.

regards,
dan carpenter