On Sun, Mar 8, 2026 at 5:06 PM Linus Walleij [off-list ref] wrote:

On Sun, Mar 8, 2026 at 3:15 AM Rosen Penev [off-list ref] wrote:

quoted

Use a flexible array member to combine kzalloc and kcalloc.

Signed-off-by: Rosen Penev <redacted>

(...)

quoted

 struct msc313_gpio {
        void __iomem *base;
        const struct msc313_gpio_data *gpio_data;

Do you wanna add:

const unsigned int saved_size;

So in the code there's

for (i = 0; i < gpio->gpio_data->num; i++)

which is equivalent to match->num.

__counted_by doesn't support pointers AFAIK.

quoted

-       u8 *saved;
+       u8 saved[];

u8 saved[] __counted_by(saved_size);

quoted

 static int msc313_gpio_set(struct gpio_chip *chip, unsigned int offset, int value)

@@ -631,16 +631,12 @@ static int msc313_gpio_probe(struct platform_device *pdev)
        if (!parent_domain)
                return -ENODEV;

-       gpio = devm_kzalloc(dev, sizeof(*gpio), GFP_KERNEL);
+       gpio = devm_kzalloc(dev, struct_size(gpio, saved, match_data->num), GFP_KERNEL);
        if (!gpio)
                return -ENOMEM;

gpio->saved_size = match_data->num;

I know it takes some bytes more but it feels way safer.

Yours,
Linus Walleij