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 atmel_ebi_dev.

[1] https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci

Cc: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Cc: Nicolas Ferre <nicolas.ferre@microchip.com>
Cc: Alexandre Belloni <alexandre.belloni@bootlin.com>
Cc: Claudiu Beznea <claudiu.beznea@tuxon.dev>
Cc: linux-arm-kernel@lists.infradead.org
Signed-off-by: Kees Cook <keescook@chromium.org>
---
 drivers/memory/atmel-ebi.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/memory/atmel-ebi.c b/drivers/memory/atmel-ebi.c
index 635966d705cb..ec6100bc94c5 100644
--- a/drivers/memory/atmel-ebi.c
+++ b/drivers/memory/atmel-ebi.c
@@ -30,7 +30,7 @@ struct atmel_ebi_dev {
 	struct atmel_ebi *ebi;
 	u32 mode;
 	int numcs;
-	struct atmel_ebi_dev_config configs[];
+	struct atmel_ebi_dev_config configs[] __counted_by(numcs);
 };
 
 struct atmel_ebi_caps {
-- 
2.34.1

On Fri, 22 Sep 2023 10:52:15 -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 atmel_ebi_dev.
> 
> [...]

Applied, thanks!

[1/1] memory: atmel-ebi: Annotate struct atmel_ebi_dev with __counted_by
      https://git.kernel.org/krzk/linux-mem-ctrl/c/c1f2c81631df7654c249a457b7a54bbc36042248

Best regards,
-- 
Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>

On 9/22/23 11:52, 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 atmel_ebi_dev.
> 
> [1] https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci
> 
> Cc: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
> Cc: Nicolas Ferre <nicolas.ferre@microchip.com>
> Cc: Alexandre Belloni <alexandre.belloni@bootlin.com>
> Cc: Claudiu Beznea <claudiu.beznea@tuxon.dev>
> Cc: linux-arm-kernel@lists.infradead.org
> Signed-off-by: Kees Cook <keescook@chromium.org>

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

Thanks
-- 
Gustavo

> ---
>   drivers/memory/atmel-ebi.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/memory/atmel-ebi.c b/drivers/memory/atmel-ebi.c
> index 635966d705cb..ec6100bc94c5 100644
> --- a/drivers/memory/atmel-ebi.c
> +++ b/drivers/memory/atmel-ebi.c
> @@ -30,7 +30,7 @@ struct atmel_ebi_dev {
>   	struct atmel_ebi *ebi;
>   	u32 mode;
>   	int numcs;
> -	struct atmel_ebi_dev_config configs[];
> +	struct atmel_ebi_dev_config configs[] __counted_by(numcs);
>   };
>   
>   struct atmel_ebi_caps {