linux-kernel - Re: [PATCH 01/23] gpiolib: Correct wrong kfree() usage for `kobj->name`

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Message-ID: <CAMRc=McNVLS3qs=ZSY8T=rNGwTd8amvFbz+mOcDZeiAV6Mw-UQ@mail.gmail.com>
Date: Tue, 20 Jan 2026 10:43:55 +0100
From: Bartosz Golaszewski <brgl@...nel.org>
To: Tzung-Bi Shih <tzungbi@...nel.org>
Cc: Jason Gunthorpe <jgg@...dia.com>, Benson Leung <bleung@...omium.org>, 
	Greg Kroah-Hartman <gregkh@...uxfoundation.org>, "Rafael J . Wysocki" <rafael@...nel.org>, 
	Danilo Krummrich <dakr@...nel.org>, Linus Walleij <linusw@...nel.org>, Jonathan Corbet <corbet@....net>, 
	Shuah Khan <shuah@...nel.org>, linux-doc@...r.kernel.org, linux-kernel@...r.kernel.org, 
	chrome-platform@...ts.linux.dev, linux-kselftest@...r.kernel.org, 
	Laurent Pinchart <laurent.pinchart@...asonboard.com>, 
	Wolfram Sang <wsa+renesas@...g-engineering.com>, Simona Vetter <simona.vetter@...ll.ch>, 
	Dan Williams <dan.j.williams@...el.com>, linux-gpio@...r.kernel.org, 
	stable@...r.kernel.org
Subject: Re: [PATCH 01/23] gpiolib: Correct wrong kfree() usage for `kobj->name`

On Tue, Jan 20, 2026 at 5:30 AM Tzung-Bi Shih <tzungbi@...nel.org> wrote:
>
> Generally, I think we can try to move device_initialize() earlier in the
> function.  On error handling paths, just put_device() for it.  In the
> .release() callback, free the resource iff it has initialized.
>
> > In theory yes but you wouldn't be the first one to attempt to improve
> > it. This code is very brittle when it comes to GPIO chips that need to
> > be initialized very early into the boot process. I'm talking old
> > drivers in arch which call this function without even an associated
> > parent struct device. When I'm looking at it now, it does seem
> > possible to call device_initialize() early but whether that will work
> > correctly for all existing users is a bigger question.
>
> FWIW: found a very early stage calling path when I was investigating
> `gpiolib_initialized`: start_kernel() -> init_IRQ() -> dove_init_irq() ->
> orion_gpio_init() -> gpiochip_add_data() -> gpiochip_add_data_with_key().
>
> Prior to aab5c6f20023 ("gpio: set device type for GPIO chips"),
> device_initialize() is also called in gpiochip_add_data_with_key().  It
> seems to me it's possible to move it back to gpiochip_add_data_with_key()
> as 03/23 does, and move it earlier in the function.

Sounds good, let's try it next cycle!

Tzung-Bi: please make it a change separate from the wider Revocable
series for GPIO.

Bart