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

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

[Kees Cook]

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>
---
 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 *
-- 
2.34.1

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

[Gustavo A. R. Silva]

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 *

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

[Bjorn Andersson]

On Fri, 22 Sep 2023 10:54:14 -0700, 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.
> 
> [...]

Applied, thanks!

[1/1] soc: qcom: smem: Annotate struct qcom_smem with __counted_by
      commit: 433ce46a97116f431ee114b4607143860aad4054

Best regards,
-- 
Bjorn Andersson <andersson@kernel.org>