Re: [PATCH v4] media: verisilicon: Fix kernel panic due to __initconst misuse

[Frank Li]

On Fri, Mar 06, 2026 at 11:10:57AM +0800, ming.qian@xxxxxxxxxxx wrote:
> From: Ming Qian <ming.qian@xxxxxxxxxxx>
>
> Fix a kernel panic when probing the driver as a module:
>
>   Unable to handle kernel paging request at virtual address
>   ffffd9c18eb05000
>   of_find_matching_node_and_match+0x5c/0x1a0
>   hantro_probe+0x2f4/0x7d0 [hantro_vpu]
>
> The imx8mq_vpu_shared_resources array is referenced by variant
> structures through their shared_devices field. When built as a
> module, __initconst causes this data to be freed after module
> init, but it's later accessed during probe, causing a page fault.
>
> The imx8mq_vpu_shared_resources is referenced from non-init code,
> so keeping __initconst or __initconst_or_module here is wrong.
>
> Drop the __initconst annotation and let it live in the normal .rodata
> section.
>
> A bug of __initconst called from regular non-init probe code
> leading to bugs during probe deferrals or during unbind-bind cycles.
>
> Reported-by: Krzysztof Kozlowski <krzysztof.kozlowski@xxxxxxxxxxxxxxxx>
> Closes: https://lore.kernel.org/all/68ef934f-baa0-4bf6-93d8-834bbc441e66@xxxxxxxxxx/
> Reported-by: Franz Schnyder <franz.schnyder@xxxxxxxxxxx>
> Closes: https://lore.kernel.org/all/n3qmcb62tepxltoskpf7ws6yiirc2so62ia23b42rj3wlmpl67@rvkbuirx7kkp/
> Fixes: e0203ddf9af7 ("media: verisilicon: Avoid G2 bus error while decoding H.264 and HEVC")
> Suggested-by: Krzysztof Kozlowski <krzysztof.kozlowski@xxxxxxxxxxxxxxxx>
> Suggested-by: Marco Felsch <m.felsch@xxxxxxxxxxxxxx>
> Reviewed-by: Marco Felsch <m.felsch@xxxxxxxxxxxxxx>
> Signed-off-by: Ming Qian <ming.qian@xxxxxxxxxxx>
> ---

Reviewed-by: Frank Li <Frank.Li@xxxxxxx>

> v4
> - Increase the diff context length to pass the checkpatch.pl.
> - Discard irrelevant changes to sentinel
>
> v3
> - Add missing Reported-by and Suggested-by tag
> - Add commas to pass checkpatch
>
> v2
> - Remove __initconst
> - Add missing Reported-by tag
> - Add missing Suggested-by tag
> - Remove comments of sentinel to pass checkpatch.pl
>
>  drivers/media/platform/verisilicon/imx8m_vpu_hw.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/media/platform/verisilicon/imx8m_vpu_hw.c b/drivers/media/platform/verisilicon/imx8m_vpu_hw.c
> index 6f8e43b7f157..fa4224de4b99 100644
> --- a/drivers/media/platform/verisilicon/imx8m_vpu_hw.c
> +++ b/drivers/media/platform/verisilicon/imx8m_vpu_hw.c
> @@ -342,9 +342,9 @@ const struct hantro_variant imx8mq_vpu_variant = {
>  	.reg_names = imx8mq_reg_names,
>  	.num_regs = ARRAY_SIZE(imx8mq_reg_names)
>  };
>
> -static const struct of_device_id imx8mq_vpu_shared_resources[] __initconst = {
> +static const struct of_device_id imx8mq_vpu_shared_resources[] = {
>  	{ .compatible = "nxp,imx8mq-vpu-g1", },
>  	{ .compatible = "nxp,imx8mq-vpu-g2", },
>  	{ /* sentinel */ }
>  };
>
> base-commit: f505e978d1a0442adbbde48aed38c084ddea6d6e
> prerequisite-patch-id: 0000000000000000000000000000000000000000
> --
> 2.52.0
>