On 03/02/25 22:47, Andy Shevchenko wrote:
> Add the __counted_by() compiler attribute to the flexible array member
> volumes to improve access bounds-checking via CONFIG_UBSAN_BOUNDS and
> CONFIG_FORTIFY_SOURCE.
>
> Use struct_size() instead of manually calculating the number of bytes to
> allocate the private structure with a buffer.
>
> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Thanks!
--
Gustavo
> ---
> drivers/gpio/gpio-74x164.c | 10 +++++-----
> 1 file changed, 5 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/gpio/gpio-74x164.c b/drivers/gpio/gpio-74x164.c
> index 70c662bbca7b..7844f8a58834 100644
> --- a/drivers/gpio/gpio-74x164.c
> +++ b/drivers/gpio/gpio-74x164.c
> @@ -30,7 +30,7 @@ struct gen_74x164_chip {
> * register at the end of the transfer. So, to have a logical
> * numbering, store the bytes in reverse order.
> */
> - u8 buffer[];
> + u8 buffer[] __counted_by(registers);
> };
>
> static int __gen_74x164_write_config(struct gen_74x164_chip *chip)
> @@ -97,6 +97,7 @@ static int gen_74x164_direction_output(struct gpio_chip *gc,
>
> static int gen_74x164_probe(struct spi_device *spi)
> {
> + struct device *dev = &spi->dev;
> struct gen_74x164_chip *chip;
> u32 nregs;
> int ret;
> @@ -116,10 +117,12 @@ static int gen_74x164_probe(struct spi_device *spi)
> return -EINVAL;
> }
>
> - chip = devm_kzalloc(&spi->dev, sizeof(*chip) + nregs, GFP_KERNEL);
> + chip = devm_kzalloc(dev, struct_size(chip, buffer, nregs), GFP_KERNEL);
> if (!chip)
> return -ENOMEM;
>
> + chip->registers = nregs;
> +
> chip->gpiod_oe = devm_gpiod_get_optional(&spi->dev, "enable",
> GPIOD_OUT_LOW);
> if (IS_ERR(chip->gpiod_oe))
> @@ -133,10 +136,7 @@ static int gen_74x164_probe(struct spi_device *spi)
> chip->gpio_chip.set = gen_74x164_set_value;
> chip->gpio_chip.set_multiple = gen_74x164_set_multiple;
> chip->gpio_chip.base = -1;
> -
> - chip->registers = nregs;
> chip->gpio_chip.ngpio = GEN_74X164_NUMBER_GPIOS * chip->registers;
> -
> chip->gpio_chip.can_sleep = true;
> chip->gpio_chip.parent = &spi->dev;
> chip->gpio_chip.owner = THIS_MODULE;