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authorKirill Tkhai <ktkhai@virtuozzo.com>2018-03-05 14:31:10 +0300
committerDavid S. Miller <davem@davemloft.net>2018-03-05 18:48:27 +0300
commitd217472410a033cdef5b8fba4393b466ee3c3bbc (patch)
tree59de97ef33c8b1ea12e06054ace543612f89e506 /net
parentc60a246cd366b5da5a12cc972a25e41bc536706f (diff)
downloadlinux-d217472410a033cdef5b8fba4393b466ee3c3bbc.tar.xz
net: Convert caif_net_ops
Init method just allocates memory for new cfg, and assigns net_generic(net, caif_net_id). Despite there is synchronize_rcu() on error path in cfcnfg_create(), in real this function does not use global lists, so it looks like this synchronize_rcu() is some legacy inheritance. Exit method removes caif devices under rtnl_lock(). There could be a problem, if someone from foreign net pernet_operations dereference caif_net_id of this net. It's dereferenced in get_cfcnfg() and caif_device_list(). get_cfcnfg() is used from netdevice notifiers, where they are called under rtnl_lock(). The notifiers can't be called from foreign nets pernet_operations. Also, it's used from caif_disconnect_client() and from caif_connect_client(). The both of the functions work with caif socket, and there is the only possibility to have a socket, when the net is dead. This may happen only of the socket was created as kern using sk_alloc(). Grep by PF_CAIF shows we do not create kern caif sockets, so get_cfcnfg() is safe. caif_device_list() is used in netdevice notifiers and exit method under rtnl lock. Also, from caif_get() used in the netdev notifiers and in caif_flow_cb(). The last item is skb destructor. Since there are no kernel caif sockets nobody can send net a packet in parallel with init/exit, so this is also safe. So, these pernet_operations are safe to be async. Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net')
-rw-r--r--net/caif/caif_dev.c1
1 files changed, 1 insertions, 0 deletions
diff --git a/net/caif/caif_dev.c b/net/caif/caif_dev.c
index e0adcd123f48..7a78268cc572 100644
--- a/net/caif/caif_dev.c
+++ b/net/caif/caif_dev.c
@@ -544,6 +544,7 @@ static struct pernet_operations caif_net_ops = {
.exit = caif_exit_net,
.id = &caif_net_id,
.size = sizeof(struct caif_net),
+ .async = true,
};
/* Initialize Caif devices list */