linux-kernel - Re: [PATCH v2 0/4] gpio: fix SRCU bugs

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Date: Thu, 15 Feb 2024 08:43:13 +0100
From: Bartosz Golaszewski <brgl@...ev.pl>
To: Linus Walleij <linus.walleij@...aro.org>, 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>, Mark Brown <broonie@...nel.org>, 
	Dan Carpenter <dan.carpenter@...aro.org>
Cc: linux-gpio@...r.kernel.org, linux-kernel@...r.kernel.org, 
	Bartosz Golaszewski <bartosz.golaszewski@...aro.org>
Subject: Re: [PATCH v2 0/4] gpio: fix SRCU bugs

On Wed, Feb 14, 2024 at 9:44 AM Bartosz Golaszewski <brgl@...ev.pl> wrote:
>
> From: Bartosz Golaszewski <bartosz.golaszewski@...aro.org>
>
> Here are four fixes to some bugs in recent SRCU changes. The first one fixes
> an actual race condition. The other three just make lockdep happy.
>
> v1 -> v2:
> - use srcu_dereference() instead of rcu_dereference_protected() as
>   advised by Paul
> - add a patch using rcu_dereference_check(..., 1) in deprecated
>   interfaces that return the address of the RCU-protected chip structure
>   to external users (who shouldn't use it anyway but well...)
> - pick up review tags for patches 1/4 and 2/4
>
> Bartosz Golaszewski (4):
>   gpio: take the SRCU read lock in gpiod_hog()
>   gpio: cdev: use correct pointer accessors with SRCU
>   gpio: use srcu_dereference() with SRCU-protected pointers
>   gpio: don't let lockdep complain about inherently dangerous RCU usage
>
>  drivers/gpio/gpiolib-cdev.c  | 25 ++++++++++++-------------
>  drivers/gpio/gpiolib-sysfs.c |  5 +++--
>  drivers/gpio/gpiolib.c       | 32 ++++++++++++++++++--------------
>  drivers/gpio/gpiolib.h       |  3 ++-
>  4 files changed, 35 insertions(+), 30 deletions(-)
>
> --
> 2.40.1
>

Series queued.

Bart