netdev - Re: [PATCH 1/2] net: hisilicon: hns_mdio: remove incorrect ACPI

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 for Android: free password hash cracker in your pocket

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

Message-Id: <c28e16ce-d535-4af4-972b-e19376833235@app.fastmail.com>
Date: Thu, 27 Feb 2025 13:03:05 +0100
From: "Arnd Bergmann" <arnd@...db.de>
To: "Jijie Shao" <shaojijie@...wei.com>, "Arnd Bergmann" <arnd@...nel.org>,
 "Jian Shen" <shenjian15@...wei.com>, "Salil Mehta" <salil.mehta@...wei.com>,
 "Andrew Lunn" <andrew+netdev@...n.ch>,
 "David S . Miller" <davem@...emloft.net>,
 "Eric Dumazet" <edumazet@...gle.com>, "Jakub Kicinski" <kuba@...nel.org>,
 "Paolo Abeni" <pabeni@...hat.com>
Cc: "Simon Horman" <horms@...nel.org>,
 Uwe Kleine-König <u.kleine-koenig@...libre.com>,
 "Krzysztof Kozlowski" <krzysztof.kozlowski@...aro.org>,
 Netdev <netdev@...r.kernel.org>, linux-kernel@...r.kernel.org
Subject: Re: [PATCH 1/2] net: hisilicon: hns_mdio: remove incorrect ACPI_PTR annotation

On Thu, Feb 27, 2025, at 12:53, Jijie Shao wrote:
>
> if CONFIG_ACPI is disabled, ACPI_PTR() will return NULL, so
> hns_mdio_acpi_match is unused variable.
>
>
> So use #ifdef is possible and has no side effects, and many drivers do so.

Those should be cleaned up eventually, but that is separate from
the build warning.

> Of course, it also seems possible to remove ACPI_PTR(),
> But I'm not sure if it's okay to set a value to acpi_match_table if 
> CONFIG_ACPI is disabled.

Setting .acpi_match_table and .of_match_table unconditionally
is the normal case. Historically we had some drivers that
used of_match_ptr() to assign the .of_match_table in order
to allow drivers to #ifdef out the CONFIG_OF portion of the
driver for platforms that did not already use devicetree
based probing.

There are basically no platforms left that have not been
converted to devicetree yet, so there is no point in
micro-optimizing the kernel size for that case, but the
(mis)use of of_match_ptr() has been copied into drivers
after that, and most of the ACPI_PTR() users unfortunately
copied from that when drivers started supporting both.

     Arnd