Re: [PATCH] soc: qcom: smem: Annotate struct qcom_smem with __counted_by

["Gustavo A. R. Silva" <gustavo@embeddedor.com>]

On 9/22/23 11:54, 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 qcom_smem.
> 
> [1] https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci
> 
> Cc: Andy Gross <agross@kernel.org>
> Cc: Bjorn Andersson <andersson@kernel.org>
> Cc: Konrad Dybcio <konrad.dybcio@linaro.org>
> Cc: Nathan Chancellor <nathan@kernel.org>
> Cc: Nick Desaulniers <ndesaulniers@google.com>
> Cc: Tom Rix <trix@redhat.com>
> Cc: linux-arm-msm@vger.kernel.org
> Cc: llvm@lists.linux.dev
> Signed-off-by: Kees Cook <keescook@chromium.org>

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

Thanks
-- 
Gustavo

> ---
>   drivers/soc/qcom/smem.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/soc/qcom/smem.c b/drivers/soc/qcom/smem.c
> index d4a89d2bb43b..4ce9cf1477ac 100644
> --- a/drivers/soc/qcom/smem.c
> +++ b/drivers/soc/qcom/smem.c
> @@ -285,7 +285,7 @@ struct qcom_smem {
>   	struct smem_partition partitions[SMEM_HOST_COUNT];
>   
>   	unsigned num_regions;
> -	struct smem_region regions[];
> +	struct smem_region regions[] __counted_by(num_regions);
>   };
>   
>   static void *