linux_dsm_epyc7002/include/net
Johannes Berg ee1c244219 genetlink: synchronize socket closing and family removal
In addition to the problem Jeff Layton reported, I looked at the code
and reproduced the same warning by subscribing and removing the genl
family with a socket still open. This is a fairly tricky race which
originates in the fact that generic netlink allows the family to go
away while sockets are still open - unlike regular netlink which has
a module refcount for every open socket so in general this cannot be
triggered.

Trying to resolve this issue by the obvious locking isn't possible as
it will result in deadlocks between unregistration and group unbind
notification (which incidentally lockdep doesn't find due to the home
grown locking in the netlink table.)

To really resolve this, introduce a "closing socket" reference counter
(for generic netlink only, as it's the only affected family) in the
core netlink code and use that in generic netlink to wait for all the
sockets that are being closed at the same time as a generic netlink
family is removed.

This fixes the race that when a socket is closed, it will should call
the unbind, but if the family is removed at the same time the unbind
will not find it, leading to the warning. The real problem though is
that in this case the unbind could actually find a new family that is
registered to have a multicast group with the same ID, and call its
mcast_unbind() leading to confusing.

Also remove the warning since it would still trigger, but is now no
longer a problem.

This also moves the code in af_netlink.c to before unreferencing the
module to avoid having the same problem in the normal non-genl case.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-01-16 17:04:25 -05:00
..
9p
bluetooth Merge branch 'for-davem-2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2014-12-10 13:17:23 -05:00
caif
irda irda: Convert function pointer arrays and uses to const 2014-12-10 15:33:16 -05:00
iucv
netfilter Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2014-12-11 14:27:06 -08:00
netns
nfc
phonet
sctp
tc_act
6lowpan.h
act_api.h
addrconf.h
af_ieee802154.h
af_rxrpc.h
af_unix.h
af_vsock.h
ah.h
arp.h
atmclip.h
ax25.h
ax88796.h
bond_3ad.h
bond_alb.h
bond_options.h
bonding.h
busy_poll.h
cfg80211-wext.h
cfg80211.h
cfg802154.h
checksum.h
cipso_ipv4.h
cls_cgroup.h
codel.h
compat.h
datalink.h
dcbevent.h
dcbnl.h
dn_dev.h
dn_fib.h
dn_neigh.h
dn_nsp.h
dn_route.h
dn.h
dsa.h
dsfield.h
dst_ops.h
dst.h
esp.h
ethoc.h
fib_rules.h
firewire.h
flow_keys.h
flow.h
flowcache.h
fou.h
garp.h
gen_stats.h
genetlink.h genetlink: synchronize socket closing and family removal 2015-01-16 17:04:25 -05:00
geneve.h
gre.h
gro_cells.h
gue.h
icmp.h
ieee80211_radiotap.h
ieee802154_netdev.h
if_inet6.h
inet6_connection_sock.h
inet6_hashtables.h
inet_common.h
inet_connection_sock.h
inet_ecn.h
inet_frag.h
inet_hashtables.h
inet_sock.h
inet_timewait_sock.h
inetpeer.h
ip6_checksum.h
ip6_fib.h
ip6_route.h
ip6_tunnel.h
ip_fib.h
ip_tunnels.h
ip_vs.h
ip.h
ipcomp.h
ipconfig.h
ipv6.h
ipx.h
iw_handler.h
lapb.h
lib80211.h
llc_c_ac.h
llc_c_ev.h
llc_c_st.h llc: Make llc_conn_ev_qfyr_t function pointer arrays const 2014-12-10 15:21:24 -05:00
llc_conn.h
llc_if.h
llc_pdu.h
llc_s_ac.h
llc_s_ev.h
llc_s_st.h llc: Make llc_sap_action_t function pointer arrays const 2014-12-10 15:21:24 -05:00
llc_sap.h
llc.h
mac80211.h Revert "mac80211: Fix accounting of the tailroom-needed counter" 2015-01-05 10:33:46 +01:00
mac802154.h
mip6.h
mld.h
mpls.h
mrp.h
ndisc.h
neighbour.h neigh: remove next ptr from struct neigh_table 2014-12-26 17:07:08 -05:00
net_namespace.h
net_ratelimit.h
netevent.h
netlabel.h
netlink.h
netprio_cgroup.h
netrom.h
nexthop.h
nl802154.h
p8022.h
ping.h
pkt_cls.h
pkt_sched.h
protocol.h
psnap.h
raw.h
rawv6.h
red.h
regulatory.h
request_sock.h
rose.h
route.h
rtnetlink.h
sch_generic.h net: sched: cls: remove unused op put from tcf_proto_ops 2014-12-09 14:49:02 -05:00
scm.h
secure_seq.h
slhc_vj.h
snmp.h
sock.h Merge git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6 2014-12-13 13:33:26 -08:00
Space.h
stp.h
switchdev.h
tcp_memcontrol.h
tcp_states.h
tcp.h
timewait_sock.h
transp_v6.h
tso.h
udp_tunnel.h
udp.h
udplite.h put iov_iter into msghdr 2014-12-09 16:29:03 -05:00
vsock_addr.h
vxlan.h net: Generalize ndo_gso_check to ndo_features_check 2014-12-26 17:20:56 -05:00
wext.h
wimax.h
x25.h
x25device.h
xfrm.h