Hi Gustavo,
On Fri, 4 Jan 2019 11:26:37 -0600
"Gustavo A. R. Silva" <gust...@embeddedor.com> 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 = devm_kzalloc(dev, 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 = devm_kzalloc(dev, struct_size(instance, entry, count), GFP_KERNEL);
>
> This code was detected with the help of Coccinelle.
>
> Signed-off-by: Gustavo A. R. Silva <gust...@embeddedor.com>
> ---
> drivers/mtd/nand/raw/sunxi_nand.c | 5 +----
> 1 file changed, 1 insertion(+), 4 deletions(-)
>
> diff --git a/drivers/mtd/nand/raw/sunxi_nand.c
> b/drivers/mtd/nand/raw/sunxi_nand.c
> index e828ee50a201..f66fffe663bf 100644
> --- a/drivers/mtd/nand/raw/sunxi_nand.c
> +++ b/drivers/mtd/nand/raw/sunxi_nand.c
> @@ -1870,10 +1870,7 @@ static int sunxi_nand_chip_init(struct device *dev,
> struct sunxi_nfc *nfc,
> return -EINVAL;
> }
>
> - chip = devm_kzalloc(dev,
> - sizeof(*chip) +
> - (nsels * sizeof(struct sunxi_nand_chip_sel)),
> - GFP_KERNEL);
> + chip = devm_kzalloc(dev, struct_size(chip, sels, nsels), GFP_KERNEL);
> if (!chip) {
> dev_err(dev, "could not allocate chip\n");
> return -ENOMEM;
I posted the same patch a few days back [1].
[1]http://patchwork.ozlabs.org/patch/1013855/
