Re: [PATCH 01/21] dmaengine: apple-admac: Annotate struct admac_data with __counted_by

Gustavo A. R. Silva
2023-08-18T01:26:34Z

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 admac_data.
>
> [1] https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci
>
> Cc: Vinod Koul <vkoul@kernel.org>
> Cc: Hector Martin <marcan@marcan.st>
> Cc: Sven Peter <sven@svenpeter.dev>
> Cc: Alyssa Rosenzweig <alyssa@rosenzweig.io>
> Cc: asahi@lists.linux.dev
> Cc: linux-arm-kernel@lists.infradead.org
> Cc: dmaengine@vger.kernel.org
> Signed-off-by: Kees Cook <keescook@chromium.org>

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

Thanks
--
Gustavo

> ---
> drivers/dma/apple-admac.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/dma/apple-admac.c b/drivers/dma/apple-admac.c
> index 3af795635c5c..ff46260b6ebc 100644
> --- a/drivers/dma/apple-admac.c
> +++ b/drivers/dma/apple-admac.c
> @@ -128,7 +128,7 @@ struct admac_data {
> int irq;
> int irq_index;
> int nchannels;
> - struct admac_chan channels[];
> + struct admac_chan channels[] __counted_by(nchannels);
> };
>
> struct admac_tx {