Re: [PATCH v26 05/10] dt-bindings: arm: Document reboot mode magic

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 2 potential issue(s) to consider:
- [Low] dt-bindings: ineffective unevaluatedProperties allows undocumented properties
- [Low] dt-bindings: missing maxItems constraint on mode-* arrays
--

commit b385b6956b70c623850aefcc8ceb50fda4b87cc0
Author: Shivendra Pratap <shivendra.pratap@oss.qualcomm.com>

dt-bindings: arm: Document reboot mode magic

Add bindings to describe vendor-specific reboot modes. Values here
correspond to valid parameters to vendor-specific reset types in PSCI
SYSTEM_RESET2 call.

> diff --git a/Documentation/devicetree/bindings/arm/psci.yaml b/Documentation/devicetree/bindings/arm/psci.yaml
> index 0d04389c81faa..82ae25e7a3386 100644
> --- a/Documentation/devicetree/bindings/arm/psci.yaml
> +++ b/Documentation/devicetree/bindings/arm/psci.yaml
[ ... ]
> @@ -98,6 +98,39 @@ properties:
>        [1] Kernel documentation - ARM idle states bindings
>          Documentation/devicetree/bindings/cpu/idle-states.yaml
>  
> +  reboot-mode:
> +    type: object
> +    $ref: /schemas/power/reset/reboot-mode.yaml#
> +    unevaluatedProperties: false

[Severity: Low]
Does unevaluatedProperties here effectively restrict undocumented properties?

The referenced schema /schemas/power/reset/reboot-mode.yaml# has an open
additionalProperties: true. Under JSON Schema evaluation rules, this causes
all properties to be annotated as successfully evaluated.

Consequently, unevaluatedProperties: false in the referencing schema becomes
a no-op, allowing any arbitrary property to pass validation silently.

> +    properties:
> +      # "mode-normal" is just SYSTEM_RESET
> +      mode-normal: false
> +    patternProperties:
> +      "^mode-.*$":
> +        $ref: /schemas/types.yaml#/definitions/uint32-array
> +        minItems: 2

[Severity: Low]
Should this also include a maxItems constraint?

Providing a list of schemas to items constrains the initial array elements
but does not intrinsically limit the array's maximum length.

Without maxItems: 3, a device tree defining 4 or more cells for a reboot
mode will silently pass schema validation, violating the binding's up to
three 32-bit cells requirement.

> +        items:
> +          - description: arg1 (vendor-specific SYSTEM_RESET2 reset_type)
> +            minimum: 0x80000000
> +          - description: arg2 (cookie_lo in 2-cell form, cookie_hi in 3-cell form)
> +          - description: arg3 (cookie_lo in 3-cell form)

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260928-arm-psci-system_reset2-vendor-reboots-v26-0-b24e2348e8e1@oss.qualcomm.com?part=5