diff options
| author | David Ahern <dsa@cumulusnetworks.com> | 2017-01-17 14:57:36 -0800 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2017-01-18 17:07:14 -0500 |
| commit | 9ed59592e3e379b2e9557dc1d9e9ec8fcbb33f16 (patch) | |
| tree | cdbe6db947985c50e17f87f58ada3a21c7a834b3 /include/net/lwtunnel.h | |
| parent | 719ca8111402aa6157bd83a3c966d184db0d8956 (diff) | |
lwtunnel: fix autoload of lwt modules
Trying to add an mpls encap route when the MPLS modules are not loaded
hangs. For example:
CONFIG_MPLS=y
CONFIG_NET_MPLS_GSO=m
CONFIG_MPLS_ROUTING=m
CONFIG_MPLS_IPTUNNEL=m
$ ip route add 10.10.10.10/32 encap mpls 100 via inet 10.100.1.2
The ip command hangs:
root 880 826 0 21:25 pts/0 00:00:00 ip route add 10.10.10.10/32 encap mpls 100 via inet 10.100.1.2
$ cat /proc/880/stack
[<ffffffff81065a9b>] call_usermodehelper_exec+0xd6/0x134
[<ffffffff81065efc>] __request_module+0x27b/0x30a
[<ffffffff814542f6>] lwtunnel_build_state+0xe4/0x178
[<ffffffff814aa1e4>] fib_create_info+0x47f/0xdd4
[<ffffffff814ae451>] fib_table_insert+0x90/0x41f
[<ffffffff814a8010>] inet_rtm_newroute+0x4b/0x52
...
modprobe is trying to load rtnl-lwt-MPLS:
root 881 5 0 21:25 ? 00:00:00 /sbin/modprobe -q -- rtnl-lwt-MPLS
and it hangs after loading mpls_router:
$ cat /proc/881/stack
[<ffffffff81441537>] rtnl_lock+0x12/0x14
[<ffffffff8142ca2a>] register_netdevice_notifier+0x16/0x179
[<ffffffffa0033025>] mpls_init+0x25/0x1000 [mpls_router]
[<ffffffff81000471>] do_one_initcall+0x8e/0x13f
[<ffffffff81119961>] do_init_module+0x5a/0x1e5
[<ffffffff810bd070>] load_module+0x13bd/0x17d6
...
The problem is that lwtunnel_build_state is called with rtnl lock
held preventing mpls_init from registering.
Given the potential references held by the time lwtunnel_build_state it
can not drop the rtnl lock to the load module. So, extract the module
loading code from lwtunnel_build_state into a new function to validate
the encap type. The new function is called while converting the user
request into a fib_config which is well before any table, device or
fib entries are examined.
Fixes: 745041e2aaf1 ("lwtunnel: autoload of lwt modules")
Signed-off-by: David Ahern <dsa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'include/net/lwtunnel.h')
| -rw-r--r-- | include/net/lwtunnel.h | 11 |
1 files changed, 11 insertions, 0 deletions
diff --git a/include/net/lwtunnel.h b/include/net/lwtunnel.h index d4c1c75b8862..0b585f1fd340 100644 --- a/include/net/lwtunnel.h +++ b/include/net/lwtunnel.h @@ -105,6 +105,8 @@ int lwtunnel_encap_add_ops(const struct lwtunnel_encap_ops *op, unsigned int num); int lwtunnel_encap_del_ops(const struct lwtunnel_encap_ops *op, unsigned int num); +int lwtunnel_valid_encap_type(u16 encap_type); +int lwtunnel_valid_encap_type_attr(struct nlattr *attr, int len); int lwtunnel_build_state(struct net_device *dev, u16 encap_type, struct nlattr *encap, unsigned int family, const void *cfg, @@ -168,6 +170,15 @@ static inline int lwtunnel_encap_del_ops(const struct lwtunnel_encap_ops *op, return -EOPNOTSUPP; } +static inline int lwtunnel_valid_encap_type(u16 encap_type) +{ + return -EOPNOTSUPP; +} +static inline int lwtunnel_valid_encap_type_attr(struct nlattr *attr, int len) +{ + return -EOPNOTSUPP; +} + static inline int lwtunnel_build_state(struct net_device *dev, u16 encap_type, struct nlattr *encap, unsigned int family, const void *cfg, |