Ben Hutchings 84a2d3c44c ipv6: addrconf: Avoid calling netdevice notifiers with RCU read-side lock ... [ Upstream commit 4acd4945cd ] Cong Wang reports that lockdep detected suspicious RCU usage while enabling IPV6 forwarding: [ 1123.310275] =============================== [ 1123.442202] [ INFO: suspicious RCU usage. ] [ 1123.558207] 3.6.0-rc1+ #109 Not tainted [ 1123.665204] ------------------------------- [ 1123.768254] include/linux/rcupdate.h:430 Illegal context switch in RCU read-side critical section! [ 1123.992320] [ 1123.992320] other info that might help us debug this: [ 1123.992320] [ 1124.307382] [ 1124.307382] rcu_scheduler_active = 1, debug_locks = 0 [ 1124.522220] 2 locks held by sysctl/5710: [ 1124.648364] #0: (rtnl_mutex){+.+.+.}, at: [<ffffffff81768498>] rtnl_trylock+0x15/0x17 [ 1124.882211] #1: (rcu_read_lock){.+.+.+}, at: [<ffffffff81871df8>] rcu_lock_acquire+0x0/0x29 [ 1125.085209] [ 1125.085209] stack backtrace: [ 1125.332213] Pid: 5710, comm: sysctl Not tainted 3.6.0-rc1+ #109 [ 1125.441291] Call Trace: [ 1125.545281] [<ffffffff8109d915>] lockdep_rcu_suspicious+0x109/0x112 [ 1125.667212] [<ffffffff8107c240>] rcu_preempt_sleep_check+0x45/0x47 [ 1125.781838] [<ffffffff8107c260>] __might_sleep+0x1e/0x19b [...] [ 1127.445223] [<ffffffff81757ac5>] call_netdevice_notifiers+0x4a/0x4f [...] [ 1127.772188] [<ffffffff8175e125>] dev_disable_lro+0x32/0x6b [ 1127.885174] [<ffffffff81872d26>] dev_forward_change+0x30/0xcb [ 1128.013214] [<ffffffff818738c4>] addrconf_forward_change+0x85/0xc5 [...] addrconf_forward_change() uses RCU iteration over the netdev list, which is unnecessary since it already holds the RTNL lock. We also cannot reasonably require netdevice notifier functions not to sleep. Reported-by: Cong Wang <amwang@redhat.com> Signed-off-by: Ben Hutchings <bhutchings@solarflare.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>		2012-10-02 10:29:35 -07:00
..
netfilter	netfilter: ip6_tables: ip6t_ext_hdr is now static inline	2012-04-09 16:29:34 +02:00
addrconf_core.c	net: Add export.h for EXPORT_SYMBOL/THIS_MODULE to non-modules	2011-10-31 19:30:30 -04:00
addrconf.c	ipv6: addrconf: Avoid calling netdevice notifiers with RCU read-side lock	2012-10-02 10:29:35 -07:00
addrlabel.c	rtnetlink: Compute and store minimum ifinfo dump size	2011-06-09 20:38:07 -07:00
af_inet6.c	Remove all #inclusions of asm/system.h	2012-03-28 18:30:03 +01:00
ah6.c	net: remove ipv6_addr_copy()	2011-11-22 16:43:32 -05:00
anycast.c	ipv6: Remove never used function inet6_ac_check().	2012-02-01 16:14:17 -05:00
datagram.c	ipv6: helper function to get tclass	2012-02-13 00:45:38 -05:00
esp6.c	xfrm: take net hdr len into account for esp payload size calculation	2012-06-10 00:36:15 +09:00
exthdrs_core.c	ipv6: Add fragment reporting to ipv6_skip_exthdr().	2011-12-03 09:35:10 -08:00
exthdrs.c	net: remove ipv6_addr_copy()	2011-11-22 16:43:32 -05:00
fib6_rules.c	net: remove ipv6_addr_copy()	2011-11-22 16:43:32 -05:00
icmp.c	Remove all #inclusions of asm/system.h	2012-03-28 18:30:03 +01:00
inet6_connection_sock.c	Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net	2011-11-26 14:47:03 -05:00
inet6_hashtables.c	net: Compute protocol sequence numbers and fragment IDs using MD5.	2011-08-06 18:33:19 -07:00
ip6_fib.c	ipv6: fib: Restore NTF_ROUTER exception in fib6_age()	2012-07-16 09:03:46 -07:00
ip6_flowlabel.c	net: remove ipv6_addr_copy()	2011-11-22 16:43:32 -05:00
ip6_input.c	ipv6: Add fragment reporting to ipv6_skip_exthdr().	2011-12-03 09:35:10 -08:00
ip6_output.c	ipv6: fix incorrect ipsec fragment	2012-06-10 00:36:15 +09:00
ip6_tunnel.c	net: reintroduce missing rcu_assign_pointer() calls	2012-01-12 12:26:56 -08:00
ip6mr.c	Remove all #inclusions of asm/system.h	2012-03-28 18:30:03 +01:00
ipcomp6.c	inet: constify ip headers and in6_addr	2011-04-22 11:04:14 -07:00
ipv6_sockglue.c	net: implement IP_RECVTOS for IP_PKTOPTIONS	2012-02-13 00:46:41 -05:00
Kconfig
Makefile
mcast.c	ipv6: fix array index in ip6_mc_add_src()	2012-04-05 00:00:42 -04:00
mip6.c	net: remove ipv6_addr_copy()	2011-11-22 16:43:32 -05:00
ndisc.c	ipv6: fix problem with expired dst cache	2012-04-13 12:58:29 -04:00
netfilter.c	Merge branch 'modsplit-Oct31_2011' of git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux	2011-11-06 19:44:47 -08:00
proc.c	ipv6: fix per device IP snmp counters	2012-01-17 23:56:18 -05:00
protocol.c	net: add __rcu annotations to protocol	2010-10-27 11:37:31 -07:00
raw.c	ipv6: Implement IPV6_UNICAST_IF socket option.	2012-02-08 15:52:45 -05:00
reassembly.c	ipv6: fix RFC5722 comment	2012-01-30 12:58:51 -05:00
route.c	ipv6: Move ipv6 proc file registration to end of init order	2012-07-16 09:03:46 -07:00
sit.c	ipv6: sit: Convert to dst_neigh_lookup()	2012-01-26 15:23:21 -05:00
syncookies.c	net: remove ipv6_addr_copy()	2011-11-22 16:43:32 -05:00
sysctl_net_ipv6.c	net: Add export.h for EXPORT_SYMBOL/THIS_MODULE to non-modules	2011-10-31 19:30:30 -04:00
tcp_ipv6.c	tcp: fix TCP_MAXSEG for established IPv6 passive sockets	2012-04-22 17:09:35 -04:00
tunnel6.c	tunnels: add _rcu annotations	2010-10-25 13:09:45 -07:00
udp_impl.h
udp.c	datagram: Add offset argument to __skb_recv_datagram	2012-02-21 14:58:57 -05:00
udplite.c	Merge branch 'modsplit-Oct31_2011' of git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux	2011-11-06 19:44:47 -08:00
xfrm6_input.c
xfrm6_mode_beet.c	ipsec: be careful of non existing mac headers	2012-02-23 16:50:45 -05:00
xfrm6_mode_ro.c
xfrm6_mode_transport.c
xfrm6_mode_tunnel.c	ipsec: be careful of non existing mac headers	2012-02-23 16:50:45 -05:00
xfrm6_output.c	xfrm6: remove unneeded NULL check in __xfrm6_output()	2012-02-01 02:52:48 -05:00
xfrm6_policy.c	net: remove ipv6_addr_copy()	2011-11-22 16:43:32 -05:00
xfrm6_state.c	net: remove ipv6_addr_copy()	2011-11-22 16:43:32 -05:00
xfrm6_tunnel.c	ipv6: Fix return of xfrm6_tunnel_rcv()	2011-05-24 01:11:51 -04:00