linux-kernel - Re: [PATCH] firmware/psci: Don't register with debugfs if PSCI isn't available

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

Message-ID: <08679155-5b27-f2a9-522c-0a63a3525dc0@linaro.org>
Date:   Thu, 5 Jan 2023 15:13:59 +0200
From:   Dmitry Baryshkov <dmitry.baryshkov@...aro.org>
To:     Marc Zyngier <maz@...nel.org>,
        linux-arm-kernel@...ts.infradead.org, linux-kernel@...r.kernel.org
Cc:     Hector Martin <marcan@...can.st>, Mark Brown <broonie@...nel.org>,
        Ulf Hansson <ulf.hansson@...aro.org>,
        Arnd Bergmann <arnd@...db.de>,
        Mark Rutland <mark.rutland@....com>,
        Lorenzo Pieralisi <lpieralisi@...nel.org>
Subject: Re: [PATCH] firmware/psci: Don't register with debugfs if PSCI isn't
 available

On 05/01/2023 11:08, Marc Zyngier wrote:
> Contrary to popular belief, PSCI is not a universal property of an
> ARM/arm64 system. There is a garden variety of systems out there
> that don't (or even cannot) implement it.
> 
> I'm the first one deplore such a situation, but hey...
> 
> On such systems, a "cat /sys/kernel/debug/psci" results in
> fireworks, as no invocation callback is registered.
> 
> Check for the invoke_psci_fn and psci_ops.get_version pointers
> before registering with the debugfs subsystem, avoiding the
> issue altogether.
> 
> Fixes: 3137f2e60098 ("firmware/psci: Add debugfs support to ease debugging")
> Reported-by: Hector Martin <marcan@...can.st>
> Signed-off-by: Marc Zyngier <maz@...nel.org>
> Cc: Dmitry Baryshkov <dmitry.baryshkov@...aro.org>
> Cc: Mark Brown <broonie@...nel.org>
> Cc: Ulf Hansson <ulf.hansson@...aro.org>
> Cc: Arnd Bergmann <arnd@...db.de>
> Cc: Mark Rutland <mark.rutland@....com>
> Cc: Lorenzo Pieralisi <lpieralisi@...nel.org>

Acked-by: Dmitry Baryshkov <dmitry.baryshkov@...aro.org>

-- 
With best wishes
Dmitry