From: Rob Herring <robh@kernel.org>
To: Sudeep Holla <sudeep.holla@arm.com>
Cc: Rob Herring <robh+dt@kernel.org>,
linux-kernel@vger.kernel.org,
Bjorn Andersson <bjorn.andersson@linaro.org>,
Hector Yuan <hector.yuan@mediatek.com>,
Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>,
Viresh Kumar <viresh.kumar@linaro.org>,
devicetree@vger.kernel.org
Subject: Re: [PATCH v4] dt-bindings: dvfs: Add support for generic performance domains
Date: Mon, 17 May 2021 15:45:11 -0500 [thread overview]
Message-ID: <1621284311.383362.3157708.nullmailer@robh.at.kernel.org> (raw)
In-Reply-To: <20210517155458.1016707-1-sudeep.holla@arm.com>
On Mon, 17 May 2021 16:54:58 +0100, Sudeep Holla wrote:
> The CLKSCREW attack [0] exposed security vulnerabilities in energy management
> implementations where untrusted software had direct access to clock and
> voltage hardware controls. In this attack, the malicious software was able to
> place the platform into unsafe overclocked or undervolted configurations. Such
> configurations then enabled the injection of predictable faults to reveal
> secrets.
>
> Many Arm-based systems used to or still use voltage regulator and clock
> frameworks in the kernel. These frameworks allow callers to independently
> manipulate frequency and voltage settings. Such implementations can render
> systems susceptible to this form of attack.
>
> Attacks such as CLKSCREW are now being mitigated by not having direct and
> independent control of clock and voltage in the kernel and moving that
> control to a trusted entity, such as the SCP firmware or secure world
> firmware/software which are to perform sanity checking on the requested
> performance levels, thereby preventing any attempted malicious programming.
>
> With the advent of such an abstraction, there is a need to replace the
> generic clock and regulator bindings used by such devices with a generic
> performance domains bindings.
>
> [0] https://www.usenix.org/conference/usenixsecurity17/technical-sessions/presentation/tang
>
> Link: https://lore.kernel.org/r/20201116181356.804590-1-sudeep.holla@arm.com
> Cc: Rob Herring <robh+dt@kernel.org>
> Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
> Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
> ---
> Hi All,
>
> Sorry for yet another delay, I don't want to mist this for v5.14 as Mediatek
> cpufreq driver was depending on this IIRC.
>
> v3[3]->v4:
> - Dropped unnecessary phandle-array reference
> - Added maxItems = 1 for the property
>
> v2[2]->v3[3]:
> - Dropped required properties
> - Added non cpu device example
> - Updated cpu bindings too
>
> v1[1]->v2[2]:
> - Changed to Dual License
> - Added select: true, enum for #performance-domain-cells and
> $ref for performance-domain
> - Changed the example to use real existing compatibles instead
> of made-up ones
>
> Regards,
> Sudeep
>
> [1] https://lore.kernel.org/r/20201105173539.1426301-1-sudeep.holla@arm.com
> [2] https://lore.kernel.org/r/20201116181356.804590-1-sudeep.holla@arm.com
> [3] https://lore.kernel.org/r/20210407135913.2067694-1-sudeep.holla@arm.com
>
> .../devicetree/bindings/arm/cpus.yaml | 7 ++
> .../bindings/dvfs/performance-domain.yaml | 74 +++++++++++++++++++
> 2 files changed, 81 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/dvfs/performance-domain.yaml
>
My bot found errors running 'make DT_CHECKER_FLAGS=-m dt_binding_check'
on your patch (DT_CHECKER_FLAGS is new in v5.13):
yamllint warnings/errors:
dtschema/dtc warnings/errors:
Documentation/devicetree/bindings/dvfs/performance-domain.example.dt.yaml:0:0: /example-0/performance-controller@12340000: failed to match any schema with compatible: ['qcom,cpufreq-hw']
See https://patchwork.ozlabs.org/patch/1479615
This check can fail if there are any dependencies. The base for a patch
series is generally the most recent rc1.
If you already ran 'make dt_binding_check' and didn't see the above
error(s), then make sure 'yamllint' is installed and dt-schema is up to
date:
pip3 install dtschema --upgrade
Please check and re-submit.
next prev parent reply other threads:[~2021-05-17 20:45 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-05-17 15:54 [PATCH v4] dt-bindings: dvfs: Add support for generic performance domains Sudeep Holla
2021-05-17 19:17 ` Rob Herring
2021-05-19 11:23 ` Sudeep Holla
2021-05-20 3:54 ` Viresh Kumar
2021-05-17 20:45 ` Rob Herring [this message]
2021-05-19 11:20 ` Sudeep Holla
2021-05-20 19:43 ` Rob Herring
2021-05-21 4:08 ` Viresh Kumar
2021-05-21 15:24 ` Sudeep Holla
2021-05-24 9:17 ` Viresh Kumar
2021-05-24 10:05 ` Sudeep Holla
2021-10-14 10:56 ` Ulf Hansson
2021-10-14 14:55 ` Sudeep Holla
2021-10-15 9:17 ` Ulf Hansson
2021-10-19 7:24 ` Viresh Kumar
2021-10-19 13:58 ` Ulf Hansson
2021-10-20 6:24 ` Viresh Kumar
2021-10-20 10:25 ` Sudeep Holla
2021-10-21 13:34 ` Ulf Hansson
2021-10-21 15:35 ` Sudeep Holla
2021-10-20 12:11 ` Rob Herring
2021-10-21 13:13 ` Ulf Hansson
2021-10-21 13:33 ` Sudeep Holla
2021-10-21 16:01 ` Ulf Hansson
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