On Wed, 07 Apr 2021 14:59:13 +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@xxxxxxx > Cc: Rob Herring <robh+dt@xxxxxxxxxx> > Acked-by: Viresh Kumar <viresh.kumar@xxxxxxxxxx> > Signed-off-by: Sudeep Holla <sudeep.holla@xxxxxxx> > --- > > Hi All, > > Sorry for the delay, I thought I had sent this out last week and it turns > out that I had dry-run in my git email command and never removed it. Just > noticed now looking for response for this patch on the list to find out > that I never sent it out :(. > > v2[2]->v3: > - 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 > > [1] https://lore.kernel.org/lkml/20201105173539.1426301-1-sudeep.holla@xxxxxxx > [2] https://lore.kernel.org/lkml/20201116181356.804590-1-sudeep.holla@xxxxxxx > > .../devicetree/bindings/arm/cpus.yaml | 7 ++ > .../bindings/dvfs/performance-domain.yaml | 80 +++++++++++++++++++ > 2 files changed, 87 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'] /builds/robherring/linux-dt-review/Documentation/devicetree/bindings/dvfs/performance-domain.example.dt.yaml: gpu@2d000000: compatible: 'oneOf' conditional failed, one must be fixed: ['arm,mali-t624'] is too short 'arm,mali-t624' is not one of ['samsung,exynos5250-mali'] 'arm,mali-t624' is not one of ['samsung,exynos5420-mali'] 'arm,mali-t624' is not one of ['allwinner,sun50i-h6-mali'] 'arm,mali-t624' is not one of ['amlogic,meson-gxm-mali', 'realtek,rtd1295-mali'] 'arm,mali-t624' is not one of ['arm,juno-mali'] 'arm,mali-t624' is not one of ['rockchip,rk3288-mali', 'samsung,exynos5433-mali'] 'arm,mali-t624' is not one of ['rockchip,rk3399-mali'] From schema: /builds/robherring/linux-dt-review/Documentation/devicetree/bindings/gpu/arm,mali-midgard.yaml /builds/robherring/linux-dt-review/Documentation/devicetree/bindings/dvfs/performance-domain.example.dt.yaml: gpu@2d000000: 'interrupt-names' is a required property From schema: /builds/robherring/linux-dt-review/Documentation/devicetree/bindings/gpu/arm,mali-midgard.yaml /builds/robherring/linux-dt-review/Documentation/devicetree/bindings/dvfs/performance-domain.example.dt.yaml: gpu@2d000000: 'clocks' is a required property From schema: /builds/robherring/linux-dt-review/Documentation/devicetree/bindings/gpu/arm,mali-midgard.yaml /builds/robherring/linux-dt-review/Documentation/devicetree/bindings/dvfs/performance-domain.example.dt.yaml: gpu@2d000000: 'performance-domains' does not match any of the regexes: 'pinctrl-[0-9]+' From schema: /builds/robherring/linux-dt-review/Documentation/devicetree/bindings/gpu/arm,mali-midgard.yaml /builds/robherring/linux-dt-review/Documentation/devicetree/bindings/dvfs/performance-domain.example.dt.yaml: gpu@2d000000: 'oneOf' conditional failed, one must be fixed: 'interrupts' is a required property 'interrupts-extended' is a required property From schema: /builds/robherring/linux-dt-review/Documentation/devicetree/bindings/gpu/arm,mali-midgard.yaml See https://patchwork.ozlabs.org/patch/1463354 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.
