linux-kernel - Re: [PATCH 0/7] i2c: provide and use i2c_adapter_set

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Message-ID: <aU_uSLpDh2FCvAFo@smile.fi.intel.com>
Date: Sat, 27 Dec 2025 16:33:44 +0200
From: Andy Shevchenko <andriy.shevchenko@...ux.intel.com>
To: Bartosz Golaszewski <bartosz.golaszewski@....qualcomm.com>
Cc: Wolfram Sang <wsa+renesas@...g-engineering.com>,
	Mika Westerberg <mika.westerberg@...ux.intel.com>,
	Jan Dabros <jsd@...ihalf.com>, Andi Shyti <andi.shyti@...nel.org>,
	Lixu Zhang <lixu.zhang@...el.com>,
	Sakari Ailus <sakari.ailus@...ux.intel.com>,
	Binbin Zhou <zhoubinbin@...ngson.cn>,
	Fabrizio Castro <fabrizio.castro.jz@...esas.com>,
	Israel Cepeda <israel.a.cepeda.lopez@...el.com>,
	Hans de Goede <hansg@...nel.org>,
	Bartosz Golaszewski <brgl@...nel.org>, linux-i2c@...r.kernel.org,
	linux-kernel@...r.kernel.org, linux-renesas-soc@...r.kernel.org
Subject: Re: [PATCH 0/7] i2c: provide and use i2c_adapter_set_node()

On Tue, Dec 23, 2025 at 11:06:47AM +0100, Bartosz Golaszewski wrote:
> It's been another year of discussing the object life-time problems at
> conferences. I2C is one of the offenders and its problems are more
> complex than those of some other subsystems. It seems the revocable[1]
> API may make its way into the kernel this year but even with it in
> place, I2C won't be able to use it as there's currently nothing to
> *revoke*. The struct device is embedded within the i2c_adapter struct
> whose lifetime is tied to the provider device being bound to its driver.
> 
> Fixing this won't be fast and easy but nothing's going to happen if we
> don't start chipping away at it. The ultimate goal in order to be able
> to use an SRCU-based solution (revocable or otherwise) is to convert the
> embedded struct device in struct i2c_adapter into an __rcu pointer that
> can be *revoked*. To that end we need to hide all dereferences of
> adap->dev in drivers.
> 
> I2C drivers use device_set_node() to assign a firmware node directly to
> the struct device embedded in i2c_adapter. In order to hide the direct
> dereferencing: provide a dedicated interface that wraps the call to
> device_set_node() but takes the adapter as argument instead.

> [1] https://lore.kernel.org/all/20251106152330.11733-1-tzungbi@kernel.org/

Can be also made as a Link tag and some people use `b4 shazam`, that uses the
above test as a merge commit message where other tags are also being
recognized.

Have no objection and code looks good,
Reviewed-by: Andy Shevchenko <andriy.shevchenko@...ux.intel.com>

-- 
With Best Regards,
Andy Shevchenko