On Tue, 2018-01-09 at 18:00 +0300, Kirill Tkhai wrote:
> Since people may mistakenly obtain destroying net
> from net_namespace_list and from net::netns_ids
> without checking for its net::counter, let's protect
> against such situations and insert BUG_ON() to stop
> move on after this.
>
> Panic is better, than memory corruption and undefined
> behavior.
>
> Signed-off-by: Kirill Tkhai <ktk...@virtuozzo.com>
> ---
> include/net/net_namespace.h | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/include/net/net_namespace.h b/include/net/net_namespace.h
> index 10f99dafd5ac..ff0e47471d5b 100644
> --- a/include/net/net_namespace.h
> +++ b/include/net/net_namespace.h
> @@ -195,7 +195,7 @@ void __put_net(struct net *net);
>
> static inline struct net *get_net(struct net *net)
> {
> - atomic_inc(&net->count);
> + BUG_ON(atomic_inc_return(&net->count) <= 1);
> return net;
> }
Why not simply use refcount_t instead of duplicating its logic ?
