Re: [PATCH net-next] ipv6: Initialize the neighbour pointer of rt6_info on allocation

[Eric Dumazet <eric.dumazet@gmail.com>]

On Thu, 2012-07-05 at 15:18 +0200, Steffen Klassert wrote:
> git commit 97cac082 (ipv6: Store route neighbour in rt6_info struct)
> added a neighbour pointer to rt6_info. Currently we don't initialize
> this pointer at allocation time. We assume this pointer to be valid
> if it is not a null pointer, so initialize it on allocation.
> 
> Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
> ---
>  net/ipv6/route.c |    2 +-
>  1 files changed, 1 insertions(+), 1 deletions(-)
> 
> diff --git a/net/ipv6/route.c b/net/ipv6/route.c
> index ceff71d..6cc6c88 100644
> --- a/net/ipv6/route.c
> +++ b/net/ipv6/route.c
> @@ -273,7 +273,7 @@ static inline struct rt6_info *ip6_dst_alloc(struct net *net,
>  					0, 0, flags);
>  
>  	if (rt) {
> -		memset(&rt->rt6i_table, 0,
> +		memset(&rt->n, 0,
>  		       sizeof(*rt) - sizeof(struct dst_entry));
>  		rt6_init_peer(rt, table ? &table->tb6_peers : net->ipv6.peers);
>  	}

Hmm, could we find a way to avoid this for future changes ?

We know dst_entry is the first field, so maybe :

if (rt) {
	struct dst_entry *dst = (struct dst_entry *)rt;

	memset(dst + 1, 0, sizeof(*rt) - sizeof(*dst));