Re: [PATCH 04/21] dmaengine: fsl-edma: Annotate struct fsl_edma_desc with __counted_by

Gustavo A. R. Silva
2023-08-18T01:26:02Z

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 fsl_edma_desc.
>
> [1] https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci
>
> Cc: Vinod Koul <vkoul@kernel.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/fsl-edma-common.h | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/dma/fsl-edma-common.h b/drivers/dma/fsl-edma-common.h
> index 004ec4a6bc86..fdbc79787643 100644
> --- a/drivers/dma/fsl-edma-common.h
> +++ b/drivers/dma/fsl-edma-common.h
> @@ -135,7 +135,7 @@ struct fsl_edma_desc {
> bool iscyclic;
> enum dma_transfer_direction dirn;
> unsigned int n_tcds;
> - struct fsl_edma_sw_tcd tcd[];
> + struct fsl_edma_sw_tcd tcd[] __counted_by(n_tcds);
> };
>
> enum edma_version {