Re: [PATCH 11/21] dmaengine: st_fdma: Annotate struct st_fdma_desc with __counted_by

Gustavo A. R. Silva
2023-08-18T01:27:05Z

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 st_fdma_desc.
>
> [1] https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci
>
> Cc: Vinod Koul <vkoul@kernel.org>
> Cc: Patrice Chotard <patrice.chotard@foss.st.com>
> 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/st_fdma.h | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/dma/st_fdma.h b/drivers/dma/st_fdma.h
> index fa15b97a3bab..f296412e96b6 100644
> --- a/drivers/dma/st_fdma.h
> +++ b/drivers/dma/st_fdma.h
> @@ -97,7 +97,7 @@ struct st_fdma_desc {
> struct st_fdma_chan *fchan;
> bool iscyclic;
> unsigned int n_nodes;
> - struct st_fdma_sw_node node[];
> + struct st_fdma_sw_node node[] __counted_by(n_nodes);
> };
>
> enum st_fdma_type {