On Tue, Jan 08, 2019 at 09:28:16AM -0600, Gustavo A. R. Silva wrote:
> One of the more common cases of allocation size calculations is finding the
> size of a structure that has a zero-sized array at the end, along with memory
> for some number of elements for that array. For example:
>
> struct foo {
> int stuff;
> void *entry[];
> };
>
> instance = kzalloc(sizeof(struct foo) + sizeof(void *) * count, GFP_KERNEL);
>
> Instead of leaving these open-coded and prone to type mistakes, we can now
> use the new struct_size() helper:
>
> instance = kzalloc(struct_size(instance, entry, count), GFP_KERNEL);
>
> This code was detected with the help of Coccinelle.
>
> Signed-off-by: Gustavo A. R. Silva <gustavo@xxxxxxxxxxxxxx>
Applied, thank you.
> ---
> drivers/input/keyboard/tca6416-keypad.c | 4 +---
> 1 file changed, 1 insertion(+), 3 deletions(-)
>
> diff --git a/drivers/input/keyboard/tca6416-keypad.c b/drivers/input/keyboard/tca6416-keypad.c
> index dc983ab6c0ad..cdeef180aead 100644
> --- a/drivers/input/keyboard/tca6416-keypad.c
> +++ b/drivers/input/keyboard/tca6416-keypad.c
> @@ -219,9 +219,7 @@ static int tca6416_keypad_probe(struct i2c_client *client,
> return -EINVAL;
> }
>
> - chip = kzalloc(sizeof(struct tca6416_keypad_chip) +
> - pdata->nbuttons * sizeof(struct tca6416_button),
> - GFP_KERNEL);
> + chip = kzalloc(struct_size(chip, buttons, pdata->nbuttons), GFP_KERNEL);
> input = input_allocate_device();
> if (!chip || !input) {
> error = -ENOMEM;
> --
> 2.20.1
>
--
Dmitry
