Re: [PATCH 10/21] dmaengine: sprd: Annotate struct sprd_dma_dev with __counted_by

[Chunyan Zhang]

On Fri, 18 Aug 2023 at 07:59, Kees Cook <keescook@xxxxxxxxxxxx> wrote:
>
> Prepare for the coming implementation by GCC and Clang of the __counted_by
> attribute. Flexible array members annotated with __counted_by can have
> their accesses bounds-checked at run-time checking via CONFIG_UBSAN_BOUNDS
> (for array indexing) and CONFIG_FORTIFY_SOURCE (for strcpy/memcpy-family
> functions).
>
> As found with Coccinelle[1], add __counted_by for struct sprd_dma_dev.
>
> [1] https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci
>
> Cc: Vinod Koul <vkoul@xxxxxxxxxx>
> Cc: Orson Zhai <orsonzhai@xxxxxxxxx>
> Cc: Baolin Wang <baolin.wang@xxxxxxxxxxxxxxxxx>
> Cc: Chunyan Zhang <zhang.lyra@xxxxxxxxx>
> Cc: dmaengine@xxxxxxxxxxxxxxx
> Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>

Acked-by: Chunyan Zhang <zhang.lyra@xxxxxxxxx>

Thanks,
Chunyan

> ---
>  drivers/dma/sprd-dma.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/dma/sprd-dma.c b/drivers/dma/sprd-dma.c
> index 168aa0bd73a0..07871dcc4593 100644
> --- a/drivers/dma/sprd-dma.c
> +++ b/drivers/dma/sprd-dma.c
> @@ -212,7 +212,7 @@ struct sprd_dma_dev {
>         struct clk              *ashb_clk;
>         int                     irq;
>         u32                     total_chns;
> -       struct sprd_dma_chn     channels[];
> +       struct sprd_dma_chn     channels[] __counted_by(total_chns);
>  };
>
>  static void sprd_dma_free_desc(struct virt_dma_desc *vd);
> --
> 2.34.1
>