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 uniphier_pinctrl_reg_region.

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

Cc: Linus Walleij <linus.walleij@linaro.org>
Cc: Kunihiko Hayashi <hayashi.kunihiko@socionext.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: linux-gpio@vger.kernel.org
Cc: linux-arm-kernel@lists.infradead.org
Signed-off-by: Kees Cook <keescook@chromium.org>
---
 drivers/pinctrl/uniphier/pinctrl-uniphier-core.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/pinctrl/uniphier/pinctrl-uniphier-core.c b/drivers/pinctrl/uniphier/pinctrl-uniphier-core.c
index 18d3a4f69e63..fbd0fcdb42c8 100644
--- a/drivers/pinctrl/uniphier/pinctrl-uniphier-core.c
+++ b/drivers/pinctrl/uniphier/pinctrl-uniphier-core.c
@@ -31,7 +31,7 @@ struct uniphier_pinctrl_reg_region {
 	struct list_head node;
 	unsigned int base;
 	unsigned int nregs;
-	u32 vals[];
+	u32 vals[] __counted_by(nregs);
 };
 
 struct uniphier_pinctrl_priv {
-- 
2.34.1

On Fri, Sep 22, 2023 at 7:50 PM Kees Cook <keescook@chromium.org> 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 uniphier_pinctrl_reg_region.
>
> [1] https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci
>
> Cc: Linus Walleij <linus.walleij@linaro.org>
> Cc: Kunihiko Hayashi <hayashi.kunihiko@socionext.com>
> Cc: Masami Hiramatsu <mhiramat@kernel.org>
> Cc: linux-gpio@vger.kernel.org
> Cc: linux-arm-kernel@lists.infradead.org
> Signed-off-by: Kees Cook <keescook@chromium.org>

Excellent!
Patch applied.

Yours,
Linus Walleij

On 9/22/23 11:50, 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 uniphier_pinctrl_reg_region.
> 
> [1] https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci
> 
> Cc: Linus Walleij <linus.walleij@linaro.org>
> Cc: Kunihiko Hayashi <hayashi.kunihiko@socionext.com>
> Cc: Masami Hiramatsu <mhiramat@kernel.org>
> Cc: linux-gpio@vger.kernel.org
> 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/pinctrl/uniphier/pinctrl-uniphier-core.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/pinctrl/uniphier/pinctrl-uniphier-core.c b/drivers/pinctrl/uniphier/pinctrl-uniphier-core.c
> index 18d3a4f69e63..fbd0fcdb42c8 100644
> --- a/drivers/pinctrl/uniphier/pinctrl-uniphier-core.c
> +++ b/drivers/pinctrl/uniphier/pinctrl-uniphier-core.c
> @@ -31,7 +31,7 @@ struct uniphier_pinctrl_reg_region {
>   	struct list_head node;
>   	unsigned int base;
>   	unsigned int nregs;
> -	u32 vals[];
> +	u32 vals[] __counted_by(nregs);
>   };
>   
>   struct uniphier_pinctrl_priv {