On Tue, Jan 08, 2019 at 03:15:56PM -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/mcs_touchkey.c | 5 ++---
> 1 file changed, 2 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/input/keyboard/mcs_touchkey.c b/drivers/input/keyboard/mcs_touchkey.c
> index be56d4f262a7..b132662201a4 100644
> --- a/drivers/input/keyboard/mcs_touchkey.c
> +++ b/drivers/input/keyboard/mcs_touchkey.c
> @@ -113,9 +113,8 @@ static int mcs_touchkey_probe(struct i2c_client *client,
> return -EINVAL;
> }
>
> - data = kzalloc(sizeof(struct mcs_touchkey_data) +
> - sizeof(data->keycodes[0]) * (pdata->key_maxval + 1),
> - GFP_KERNEL);
> + data = kzalloc(struct_size(data, keycodes, pdata->key_maxval + 1),
> + GFP_KERNEL);
> input_dev = input_allocate_device();
> if (!data || !input_dev) {
> dev_err(&client->dev, "Failed to allocate memory\n");
> --
> 2.20.1
>
--
Dmitry
