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author | Kirill Tkhai <ktkhai@virtuozzo.com> | 2018-03-05 14:31:10 +0300 |
---|---|---|
committer | David S. Miller <davem@davemloft.net> | 2018-03-05 10:48:27 -0500 |
commit | d217472410a033cdef5b8fba4393b466ee3c3bbc (patch) | |
tree | 59de97ef33c8b1ea12e06054ace543612f89e506 | |
parent | c60a246cd366b5da5a12cc972a25e41bc536706f (diff) | |
download | linux-d217472410a033cdef5b8fba4393b466ee3c3bbc.tar.bz2 |
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>
-rw-r--r-- | net/caif/caif_dev.c | 1 |
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 */ |