Re: [PATCH 15/21] dmaengine: tegra: Annotate struct tegra_dma_desc with __counted_by

Gustavo A. R. Silva
2023-08-18T03:38:44Z

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_dma_desc.
>
> [1] https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci
>
> Cc: Vinod Koul <vkoul@kernel.org>
> Cc: Laxman Dewangan <ldewangan@nvidia.com>
> Cc: Jon Hunter <jonathanh@nvidia.com>
> Cc: Thierry Reding <thierry.reding@gmail.com>
> Cc: dmaengine@vger.kernel.org
> Cc: linux-tegra@vger.kernel.org
> Signed-off-by: Kees Cook <keescook@chromium.org>

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

Thanks
--
Gustavo

> ---
> drivers/dma/tegra186-gpc-dma.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/dma/tegra186-gpc-dma.c b/drivers/dma/tegra186-gpc-dma.c
> index 33b101001100..5e3d5f5d1e20 100644
> --- a/drivers/dma/tegra186-gpc-dma.c
> +++ b/drivers/dma/tegra186-gpc-dma.c
> @@ -221,7 +221,7 @@ struct tegra_dma_desc {
> unsigned int sg_count;
> struct virt_dma_desc vd;
> struct tegra_dma_channel *tdc;
> - struct tegra_dma_sg_req sg_req[];
> + struct tegra_dma_sg_req sg_req[] __counted_by(sg_count);
> };
>
> /*