linux-kernel - Re: [PATCH v2 1/3] gpiolib: remove the GPIO device from the list when it's unregistered

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Date: Tue, 2 Jan 2024 23:11:35 +0100
From: Linus Walleij <linus.walleij@...aro.org>
To: Bartosz Golaszewski <brgl@...ev.pl>
Cc: linux-gpio@...r.kernel.org, linux-kernel@...r.kernel.org, 
	Bartosz Golaszewski <bartosz.golaszewski@...aro.org>
Subject: Re: [PATCH v2 1/3] gpiolib: remove the GPIO device from the list when
 it's unregistered

On Tue, Jan 2, 2024 at 4:59 PM Bartosz Golaszewski <brgl@...ev.pl> wrote:

> From: Bartosz Golaszewski <bartosz.golaszewski@...aro.org>
>
> If we wait until the GPIO device's .release() callback gets invoked
> before we remove it from the global device list, then we risk that
> someone will look it up using gpio_device_find() between where we
> dropped the last reference and before .release() is done taking a
> reference again to an object that's being released.
>
> The device must be removed when it's being unregistered - just like how
> we remove it from the GPIO bus.
>
> Fixes: ff2b13592299 ("gpio: make the gpiochip a real device")
> Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@...aro.org>

Makes sense!
Reviewed-by: Linus Walleij <linus.walleij@...aro.org>

Yours,
Linus Walleij