Christophe JAILLET wrote:
> 'n_tables' is small, UDP_TUNNEL_NIC_MAX_TABLES = 4 as a maximum. So there
> is no real point to allocate the 'entries' pointers array with a dedicate
> memory allocation.
>
> Using a flexible array for struct udp_tunnel_nic->entries avoids the
> overhead of an additional memory allocation.
>
> This also saves an indirection when the array is accessed.
>
> Finally, __counted_by() can be used for run-time bounds checking if
> configured and supported by the compiler.
>
> Signed-off-by: Christophe JAILLET <christophe.jaillet@xxxxxxxxxx>
> ---
> net/ipv4/udp_tunnel_nic.c | 11 ++---------
> 1 file changed, 2 insertions(+), 9 deletions(-)
>
> diff --git a/net/ipv4/udp_tunnel_nic.c b/net/ipv4/udp_tunnel_nic.c
> index 029219749785..b6d2d16189c0 100644
> --- a/net/ipv4/udp_tunnel_nic.c
> +++ b/net/ipv4/udp_tunnel_nic.c
> @@ -47,7 +47,7 @@ struct udp_tunnel_nic {
>
> unsigned int n_tables;
> unsigned long missed;
> - struct udp_tunnel_nic_table_entry **entries;
> + struct udp_tunnel_nic_table_entry *entries[] __counted_by(n_tables);
> };
>
> /* We ensure all work structs are done using driver state, but not the code.
> @@ -725,16 +725,12 @@ udp_tunnel_nic_alloc(const struct udp_tunnel_nic_info *info,
> struct udp_tunnel_nic *utn;
> unsigned int i;
>
> - utn = kzalloc(sizeof(*utn), GFP_KERNEL);
> + utn = kzalloc(struct_size(utn, entries, n_tables), GFP_KERNEL);
> if (!utn)
> return NULL;
> utn->n_tables = n_tables;
Should utn->n_tables be initialized before first use of
struct_size(utn, entries, n_tables)?
