From: Tzung-Bi Shih <tzungbi@kernel.org>
To: Linus Walleij <linusw@kernel.org>
Cc: Bartosz Golaszewski <brgl@kernel.org>,
linux-gpio@vger.kernel.org, linux-kernel@vger.kernel.org,
stable@vger.kernel.org
Subject: Re: [PATCH v2] gpio: Fix resource leaks on errors in gpiochip_add_data_with_key()
Date: Thu, 5 Feb 2026 09:34:57 +0000 [thread overview]
Message-ID: <aYRkQRqmJZ-CMEhU@google.com> (raw)
In-Reply-To: <CAD++jL=vkMYQSKxq+5LsEW7aQAkbvVf00gv64hYRjWwsqzSHZg@mail.gmail.com>
On Tue, Feb 03, 2026 at 10:35:14AM +0100, Linus Walleij wrote:
> On Tue, Feb 3, 2026 at 7:02 AM Tzung-Bi Shih <tzungbi@kernel.org> wrote:
> > Also reorder the instructions to make the error handling simpler.
> > Now gpiochip_add_data_with_key() roughly looks like:
> >
> > >>> Some memory allocation. Go to ERR ZONE 1 on errors.
> > >>> device_initialize().
> >
> > (gpiodev_release() takes over the responsibility for freeing the
> > resources of `gdev->dev`. The subsequent error handling paths
> > shouldn't go through ERR ZONE 1 again which leads to double free.)
>
> This doesn't need to be parenthesized, it should be pointed out
> so people can follow it, also:
>
[...]
> > + device_initialize(&gdev->dev);
> > + gdev->dev.type = &gpio_dev_type;
>
>
> This is the point where, from this point on, gpiodev_release() will
> get called from the type.
>
> This is worth a comment in the code don't you think?
>
> Something like:
>
> /*
> * After this point any allocated resources will be free():d by
> * gpiodev_release(), if you add new resources then make sure
> * they get free():ed there.
> */
> gdev->dev.type = &gpio_dev_type;
>
> This helps developers to do the right thing.
>
> With that added comment:
> Reviewed-by: Linus Walleij <linusw@kernel.org>
Thanks for your review. Fix both of them in v3
https://lore.kernel.org/all/20260205092840.2574840-1-tzungbi@kernel.org/.
prev parent reply other threads:[~2026-02-05 9:35 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-02-03 6:02 [PATCH v2] gpio: Fix resource leaks on errors in gpiochip_add_data_with_key() Tzung-Bi Shih
2026-02-03 9:35 ` Linus Walleij
2026-02-05 9:34 ` Tzung-Bi Shih [this message]
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