Re: [PATCH 02/21] dmaengine: at_hdmac: Annotate struct at_desc 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 at_desc.
>
> [1] https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci
>
> Cc: Vinod Koul <vkoul@xxxxxxxxxx>
> Cc: Ludovic Desroches <ludovic.desroches@xxxxxxxxxxxxx>
> Cc: Tudor Ambarus <tudor.ambarus@xxxxxxxxxx>
> Cc: linux-arm-kernel@xxxxxxxxxxxxxxxxxxx
> Cc: dmaengine@xxxxxxxxxxxxxxx
> Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>

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

Thanks
--
Gustavo

> ---
>   drivers/dma/at_hdmac.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/dma/at_hdmac.c b/drivers/dma/at_hdmac.c
> index b2876f67471f..b66c7f416881 100644
> --- a/drivers/dma/at_hdmac.c
> +++ b/drivers/dma/at_hdmac.c
> @@ -239,7 +239,7 @@ struct at_desc {
>   	bool				memset_buffer;
>   	dma_addr_t			memset_paddr;
>   	int				*memset_vaddr;
> -	struct atdma_sg			sg[];
> +	struct atdma_sg			sg[] __counted_by(sglen);
>   };
>   
>   /*--  Channels  --------------------------------------------------------*/