On Thu, Feb 07, 2019 at 06:44:56PM -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;
> struct boo entry[];
> };
>
> size = sizeof(struct foo) + count * sizeof(struct boo);
> instance = alloc(size, GFP_KERNEL)
>
> Instead of leaving these open-coded and prone to type mistakes, we can
> now use the new struct_size() helper:
>
> size = struct_size(instance, entry, count);
>
> This code was detected with the help of Coccinelle.
>
> Signed-off-by: Gustavo A. R. Silva <gustavo@xxxxxxxxxxxxxx>
Acked-by: Simon Horman <horms+renesas@xxxxxxxxxxxx>
Pablo, could you consider applying this?
> ---
> net/netfilter/ipvs/ip_vs_ctl.c | 6 ++----
> 1 file changed, 2 insertions(+), 4 deletions(-)
>
> diff --git a/net/netfilter/ipvs/ip_vs_ctl.c b/net/netfilter/ipvs/ip_vs_ctl.c
> index 7d6318664eb2..bcd9112f47d9 100644
> --- a/net/netfilter/ipvs/ip_vs_ctl.c
> +++ b/net/netfilter/ipvs/ip_vs_ctl.c
> @@ -2734,8 +2734,7 @@ do_ip_vs_get_ctl(struct sock *sk, int cmd, void __user *user, int *len)
> int size;
>
> get = (struct ip_vs_get_services *)arg;
> - size = sizeof(*get) +
> - sizeof(struct ip_vs_service_entry) * get->num_services;
> + size = struct_size(get, entrytable, get->num_services);
> if (*len != size) {
> pr_err("length: %u != %u\n", *len, size);
> ret = -EINVAL;
> @@ -2776,8 +2775,7 @@ do_ip_vs_get_ctl(struct sock *sk, int cmd, void __user *user, int *len)
> int size;
>
> get = (struct ip_vs_get_dests *)arg;
> - size = sizeof(*get) +
> - sizeof(struct ip_vs_dest_entry) * get->num_dests;
> + size = struct_size(get, entrytable, get->num_dests);
> if (*len != size) {
> pr_err("length: %u != %u\n", *len, size);
> ret = -EINVAL;
> --
> 2.20.1
>
