Re: [PATCH net-next] mlxsw: spectrum: acl: Use struct_size() in kzalloc()

From: Jiri Pirko
Date: Tue Feb 26 2019 - 04:04:20 EST

Mon, Feb 25, 2019 at 08:01:32PM CET, gustavo@xxxxxxxxxxxxxx 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;
> 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 alloc_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>

Acked-by: Jiri Pirko <jiri@xxxxxxxxxxxx>