Re: [PATCH net-next] igc: Use struct_size() helper

From: David Miller
Date: Sat Feb 09 2019 - 02:04:39 EST


From: "Gustavo A. R. Silva" <gustavo@xxxxxxxxxxxxxx>
Date: Thu, 7 Feb 2019 22:19:45 -0600

> 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;
> struct boo entry[];
> };
>
> size = sizeof(struct foo) + count * sizeof(struct boo);
> instance = kzalloc(size, 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)
>
> Notice that, in this case, variable size is not necessary, hence
> it is removed.
>
> This code was detected with the help of Coccinelle.
>
> Signed-off-by: Gustavo A. R. Silva <gustavo@xxxxxxxxxxxxxx>

Applied.