linux-kernel - Re: [PATCH] PCI: rcar-host: Add static assertion to check !PCI_LOCKLESS

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: <c1da4b74-0fd0-437a-88da-c31c681b6c5d@mailbox.org>
Date: Wed, 24 Sep 2025 01:42:24 +0200
From: Marek Vasut <marek.vasut@...lbox.org>
To: Geert Uytterhoeven <geert@...ux-m68k.org>,
 Marek Vasut <marek.vasut+renesas@...lbox.org>
Cc: linux-pci@...r.kernel.org, Krzysztof Wilczyński
 <kwilczynski@...nel.org>, Bjorn Helgaas <bhelgaas@...gle.com>,
 Geert Uytterhoeven <geert+renesas@...der.be>,
 Lorenzo Pieralisi <lpieralisi@...nel.org>,
 Magnus Damm <magnus.damm@...il.com>, Manivannan Sadhasivam
 <mani@...nel.org>, Marek Vasut <marek.vasut+renesas@...il.com>,
 Rob Herring <robh@...nel.org>,
 Yoshihiro Shimoda <yoshihiro.shimoda.uh@...esas.com>,
 linux-kernel@...r.kernel.org, linux-renesas-soc@...r.kernel.org
Subject: Re: [PATCH] PCI: rcar-host: Add static assertion to check
 !PCI_LOCKLESS_CONFIG

On 9/22/25 5:48 PM, Marek Vasut wrote:

Hello Geert,

>>> +/*
>>> + * This driver can not function correctly without PCIe subsystem level
>>> + * config space access serialization. In case PCI_LOCKLESS_CONFIG is
>>> + * ever enabled on ARM, complain loudly so the driver can be updated
>>> + * accordingly.
>>> + */
>>> +static_assert(!IS_ENABLED(CONFIG_PCI_LOCKLESS_CONFIG));
>>> +
>>>   struct rcar_msi {
>>>          DECLARE_BITMAP(used, INT_PCI_MSI_NR);
>>>          struct irq_domain *domain;
>>
>> This causes a build failure when compile-testing, e.g. x86 allmodconfig.
>> Using "depends on !PCI_LOCKLESS_CONFIG" instead would avoid that,
>> but indeed has the disadvantage that it wouldn't complain loudly when
>> PCI_LOCKLESS_CONFIG would ever be enabled on ARM64...
> All right, let's also wait for input from PCI maintainers. It seems both 
> alternatives -- static_assert() and !PCI_LOCKLESS_CONFIG have their own 
> disadvantages, maybe there is a third option.

Maybe we can try with both.

-- 
Best regards,
Marek Vasut