Re: [PATCH v3 3/3] arm64: zynqmp: Add ALINX EdgeBoard FZ3A

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [High] dts: memory corruption due to memory@0 truncation without reserved-memory
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commit 47a176ea68469cbcbe7f485f00a695a0a5b3915f
Author: Pufan Jin <cyan2254650260@gmail.com>

arm64: zynqmp: Add ALINX EdgeBoard FZ3A

Add device tree for the ALINX EdgeBoard FZ3A, a single board computer
based on the Xilinx Zynq UltraScale+ XCZU3EG SoC.

Link: https://ai.baidu.com/tech/hardware/deepkit
Link: https://ai.baidu.com/ai-doc/HWCE/8kq9b2121
Link: https://www.alinx.com/

> diff --git a/arch/arm64/boot/dts/xilinx/zynqmp-alinx-edgeboard-fz3a.dts b/arch/arm64/boot/dts/xilinx/zynqmp-alinx-edgeboard-fz3a.dts
> new file mode 100644
> index 0000000000000..6cad90091a4c9
> --- /dev/null
> +++ b/arch/arm64/boot/dts/xilinx/zynqmp-alinx-edgeboard-fz3a.dts

[ ... ]

> +	reserved_memory: reserved-memory {
> +		ranges;
> +		#address-cells = <2>;
> +		#size-cells = <2>;
> +
> +		linux_cma: cma {
> +			compatible = "shared-dma-pool";
> +			alloc-ranges = <0x0 0x0 0x0 0x7ff00000>;
> +			reusable;
> +			size = <0x0 0x20000000>;
> +		};
> +	};
> +
> +	memory@0 {
> +		device_type = "memory";
> +		reg = <0x0 0x0 0x0 0x7ff00000>;
> +	};

[Severity: High]
Does this truncated memory range safely protect firmware memory from Linux?

ZynqMP U-Boot typically features automatic memory fixups
(fdt_fixup_memory_banks) which overwrite the reg property of memory@0 to
the full hardware-detected DDR size before booting Linux.

Since the device tree lacks a corresponding reserved-memory node with
no-map for this 1MB region, Linux might see the U-Boot expanded memory
range, map the entire memory, and allocate from the firmware's region,
potentially leading to memory corruption or boot crashes.

Should this firmware region be explicitly reserved using a reserved-memory
child node with no-map instead?

> +};

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Sashiko AI review · https://sashiko.dev/#/patchset/20261014175020.62907-1-cyan2254650260@gmail.com?part=3