Re: [PATCH 16/21] dmaengine: tegra210-adma: Annotate struct tegra_adma with __counted_by

[Gustavo A. R. Silva]

On 8/17/23 17:58, Kees Cook 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 tegra_adma.
>
> [1] https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci
>
> Cc: Vinod Koul <vkoul@xxxxxxxxxx>
> Cc: Laxman Dewangan <ldewangan@xxxxxxxxxx>
> Cc: Jon Hunter <jonathanh@xxxxxxxxxx>
> Cc: Thierry Reding <thierry.reding@xxxxxxxxx>
> Cc: dmaengine@xxxxxxxxxxxxxxx
> Cc: linux-tegra@xxxxxxxxxxxxxxx
> Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>

Reviewed-by: Gustavo A. R. Silva <gustavoars@xxxxxxxxxx>

Thanks
--
Gustavo

> ---
>   drivers/dma/tegra210-adma.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/dma/tegra210-adma.c b/drivers/dma/tegra210-adma.c
> index e557bada1510..cea33912a4c9 100644
> --- a/drivers/dma/tegra210-adma.c
> +++ b/drivers/dma/tegra210-adma.c
> @@ -162,7 +162,7 @@ struct tegra_adma {
>   	const struct tegra_adma_chip_data *cdata;
>   
>   	/* Last member of the structure */
> -	struct tegra_adma_chan		channels[];
> +	struct tegra_adma_chan		channels[] __counted_by(nr_channels);
>   };
>   
>   static inline void tdma_write(struct tegra_adma *tdma, u32 reg, u32 val)