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

[Marco Felsch]

Hi Ming,

On 26-03-05, 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.
> 
> Use __initconst_or_module to keep the data available when built
> as a module while still allowing it to be freed when built-in.

would be nice if I get at least some credit for pointing to the correct
fix ;)

> Fixes: e0203ddf9af7 ("media: verisilicon: Avoid G2 bus error while decoding H.264 and HEVC")
> Signed-off-by: Ming Qian <ming.qian@xxxxxxxxxxx>

However, patch looks fine:

Reviewed-by: Marco Felsch <m.felsch@xxxxxxxxxxxxxx>

> ---
>  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..fa429e6e8281 100644
> --- a/drivers/media/platform/verisilicon/imx8m_vpu_hw.c
> +++ b/drivers/media/platform/verisilicon/imx8m_vpu_hw.c
> @@ -343,7 +343,7 @@ const struct hantro_variant imx8mq_vpu_variant = {
>  	.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[] __initconst_or_module = {
>  	{ .compatible = "nxp,imx8mq-vpu-g1", },
>  	{ .compatible = "nxp,imx8mq-vpu-g2", },
>  	{ /* sentinel */ }
> -- 
> 2.52.0
> 
> 

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