linux-kernel - Re: [PATCH 2/3] gpio: cdev: use correct pointer accessors with SRCU

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Message-ID: <CACRpkdYbfU3LV=+xEiE=+MN4xc-_zc_6WiNOP84_PzqttCsQTA@mail.gmail.com>
Date: Tue, 13 Feb 2024 22:33:46 +0100
From: Linus Walleij <linus.walleij@...aro.org>
To: Bartosz Golaszewski <brgl@...ev.pl>
Cc: Kent Gibson <warthog618@...il.com>, Alex Elder <elder@...aro.org>, 
	Geert Uytterhoeven <geert+renesas@...der.be>, "Paul E . McKenney" <paulmck@...nel.org>, 
	Andy Shevchenko <andriy.shevchenko@...ux.intel.com>, Wolfram Sang <wsa@...-dreams.de>, 
	linux-gpio@...r.kernel.org, linux-kernel@...r.kernel.org, 
	Bartosz Golaszewski <bartosz.golaszewski@...aro.org>, kernel test robot <oliver.sang@...el.com>
Subject: Re: [PATCH 2/3] gpio: cdev: use correct pointer accessors with SRCU

On Tue, Feb 13, 2024 at 10:31 AM Bartosz Golaszewski <brgl@...ev.pl> wrote:

> From: Bartosz Golaszewski <bartosz.golaszewski@...aro.org>
>
> We never dereference the chip pointer in character device code so we can
> use the lighter rcu_access_pointer() helper. This also makes lockep
> happier as it no longer complains about suspicious rcu_dereference()
> usage.
>
> Fixes: d83cee3d2bb1 ("gpio: protect the pointer to gpio_chip in gpio_device with SRCU")
> Reported-by: kernel test robot <oliver.sang@...el.com>
> Closes: https://lore.kernel.org/oe-lkp/202402122234.d85cca9b-lkp@intel.com
> Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@...aro.org>

I had to check what rcu_access_pointer() does and it's clearly the
right thing to do so:
Reviewed-by: Linus Walleij <linus.walleij@...aro.org>

Yours,
Linus Walleij