Stanislaw Gruszka c74f2b2678 genetlink: release cb_lock before requesting additional module ... Requesting external module with cb_lock taken can result in the deadlock like showed below: [ 2458.111347] Showing all locks held in the system: [ 2458.111347] 1 lock held by NetworkManager/582: [ 2458.111347] #0: (cb_lock){++++++}, at: [<ffffffff8162bc79>] genl_rcv+0x19/0x40 [ 2458.111347] 1 lock held by modprobe/603: [ 2458.111347] #0: (cb_lock){++++++}, at: [<ffffffff8162baa5>] genl_lock_all+0x15/0x30 [ 2461.579457] SysRq : Show Blocked State [ 2461.580103] task PC stack pid father [ 2461.580103] NetworkManager D ffff880034b84500 4040 582 1 0x00000080 [ 2461.580103] ffff8800197ff720 0000000000000046 00000000001d5340 ffff8800197fffd8 [ 2461.580103] ffff8800197fffd8 00000000001d5340 ffff880019631700 7fffffffffffffff [ 2461.580103] ffff8800197ff880 ffff8800197ff878 ffff880019631700 ffff880019631700 [ 2461.580103] Call Trace: [ 2461.580103] [<ffffffff817355f9>] schedule+0x29/0x70 [ 2461.580103] [<ffffffff81731ad1>] schedule_timeout+0x1c1/0x360 [ 2461.580103] [<ffffffff810e69eb>] ? mark_held_locks+0xbb/0x140 [ 2461.580103] [<ffffffff817377ac>] ? _raw_spin_unlock_irq+0x2c/0x50 [ 2461.580103] [<ffffffff810e6b6d>] ? trace_hardirqs_on_caller+0xfd/0x1c0 [ 2461.580103] [<ffffffff81736398>] wait_for_completion_killable+0xe8/0x170 [ 2461.580103] [<ffffffff810b7fa0>] ? wake_up_state+0x20/0x20 [ 2461.580103] [<ffffffff81095825>] call_usermodehelper_exec+0x1a5/0x210 [ 2461.580103] [<ffffffff817362ed>] ? wait_for_completion_killable+0x3d/0x170 [ 2461.580103] [<ffffffff81095cc3>] __request_module+0x1b3/0x370 [ 2461.580103] [<ffffffff810e6b6d>] ? trace_hardirqs_on_caller+0xfd/0x1c0 [ 2461.580103] [<ffffffff8162c5c9>] ctrl_getfamily+0x159/0x190 [ 2461.580103] [<ffffffff8162d8a4>] genl_family_rcv_msg+0x1f4/0x2e0 [ 2461.580103] [<ffffffff8162d990>] ? genl_family_rcv_msg+0x2e0/0x2e0 [ 2461.580103] [<ffffffff8162da1e>] genl_rcv_msg+0x8e/0xd0 [ 2461.580103] [<ffffffff8162b729>] netlink_rcv_skb+0xa9/0xc0 [ 2461.580103] [<ffffffff8162bc88>] genl_rcv+0x28/0x40 [ 2461.580103] [<ffffffff8162ad6d>] netlink_unicast+0xdd/0x190 [ 2461.580103] [<ffffffff8162b149>] netlink_sendmsg+0x329/0x750 [ 2461.580103] [<ffffffff815db849>] sock_sendmsg+0x99/0xd0 [ 2461.580103] [<ffffffff810bb58f>] ? local_clock+0x5f/0x70 [ 2461.580103] [<ffffffff810e96e8>] ? lock_release_non_nested+0x308/0x350 [ 2461.580103] [<ffffffff815dbc6e>] ___sys_sendmsg+0x39e/0x3b0 [ 2461.580103] [<ffffffff810565af>] ? kvm_clock_read+0x2f/0x50 [ 2461.580103] [<ffffffff810218b9>] ? sched_clock+0x9/0x10 [ 2461.580103] [<ffffffff810bb2bd>] ? sched_clock_local+0x1d/0x80 [ 2461.580103] [<ffffffff810bb448>] ? sched_clock_cpu+0xa8/0x100 [ 2461.580103] [<ffffffff810e33ad>] ? trace_hardirqs_off+0xd/0x10 [ 2461.580103] [<ffffffff810bb58f>] ? local_clock+0x5f/0x70 [ 2461.580103] [<ffffffff810e3f7f>] ? lock_release_holdtime.part.28+0xf/0x1a0 [ 2461.580103] [<ffffffff8120fec9>] ? fget_light+0xf9/0x510 [ 2461.580103] [<ffffffff8120fe0c>] ? fget_light+0x3c/0x510 [ 2461.580103] [<ffffffff815dd1d2>] __sys_sendmsg+0x42/0x80 [ 2461.580103] [<ffffffff815dd222>] SyS_sendmsg+0x12/0x20 [ 2461.580103] [<ffffffff81741ad9>] system_call_fastpath+0x16/0x1b [ 2461.580103] modprobe D ffff88000f2c8000 4632 603 602 0x00000080 [ 2461.580103] ffff88000f04fba8 0000000000000046 00000000001d5340 ffff88000f04ffd8 [ 2461.580103] ffff88000f04ffd8 00000000001d5340 ffff8800377d4500 ffff8800377d4500 [ 2461.580103] ffffffff81d0b260 ffffffff81d0b268 ffffffff00000000 ffffffff81d0b2b0 [ 2461.580103] Call Trace: [ 2461.580103] [<ffffffff817355f9>] schedule+0x29/0x70 [ 2461.580103] [<ffffffff81736d4d>] rwsem_down_write_failed+0xed/0x1a0 [ 2461.580103] [<ffffffff810bb200>] ? update_cpu_load_active+0x10/0xb0 [ 2461.580103] [<ffffffff8137b473>] call_rwsem_down_write_failed+0x13/0x20 [ 2461.580103] [<ffffffff8173492d>] ? down_write+0x9d/0xb2 [ 2461.580103] [<ffffffff8162baa5>] ? genl_lock_all+0x15/0x30 [ 2461.580103] [<ffffffff8162baa5>] genl_lock_all+0x15/0x30 [ 2461.580103] [<ffffffff8162cbb3>] genl_register_family+0x53/0x1f0 [ 2461.580103] [<ffffffffa01dc000>] ? 0xffffffffa01dbfff [ 2461.580103] [<ffffffff8162d650>] genl_register_family_with_ops+0x20/0x80 [ 2461.580103] [<ffffffffa01dc000>] ? 0xffffffffa01dbfff [ 2461.580103] [<ffffffffa017fe84>] nl80211_init+0x24/0xf0 [cfg80211] [ 2461.580103] [<ffffffffa01dc000>] ? 0xffffffffa01dbfff [ 2461.580103] [<ffffffffa01dc043>] cfg80211_init+0x43/0xdb [cfg80211] [ 2461.580103] [<ffffffff810020fa>] do_one_initcall+0xfa/0x1b0 [ 2461.580103] [<ffffffff8105cb93>] ? set_memory_nx+0x43/0x50 [ 2461.580103] [<ffffffff810f75af>] load_module+0x1c6f/0x27f0 [ 2461.580103] [<ffffffff810f2c90>] ? store_uevent+0x40/0x40 [ 2461.580103] [<ffffffff810f82c6>] SyS_finit_module+0x86/0xb0 [ 2461.580103] [<ffffffff81741ad9>] system_call_fastpath+0x16/0x1b [ 2461.580103] Sched Debug Version: v0.10, 3.11.0-0.rc1.git4.1.fc20.x86_64 #1 Problem start to happen after adding net-pf-16-proto-16-family-nl80211 alias name to cfg80211 module by below commit (though that commit itself is perfectly fine): commit fb4e156886 Author: Marcel Holtmann <marcel@holtmann.org> Date: Sun Apr 28 16:22:06 2013 -0700 nl80211: Add generic netlink module alias for cfg80211/nl80211 Reported-and-tested-by: Jeff Layton <jlayton@redhat.com> Reported-by: Richard W.M. Jones <rjones@redhat.com> Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com> Reviewed-by: Pravin B Shelar <pshelar@nicira.com> Signed-off-by: David S. Miller <davem@davemloft.net>		2013-07-27 22:19:20 -07:00
..
9p	Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net	2013-07-13 17:42:22 -07:00
802	net/802/mrp: fix lockdep splat	2013-05-14 13:02:30 -07:00
8021q	vlan: fix a race in egress prio management	2013-07-18 13:07:13 -07:00
appletalk	net: pass info struct via netdevice notifier	2013-05-28 13:11:01 -07:00
atm	net: always pass struct netdev_notifier_info to netdevice notifiers	2013-05-28 21:58:54 -07:00
ax25	net: Convert uses of typedef ctl_table to struct ctl_table	2013-06-13 02:36:09 -07:00
batman-adv	net: Unmap fragment page once iterator is done	2013-06-24 01:46:01 -07:00
bluetooth	Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next	2013-07-09 18:24:39 -07:00
bridge	bridge: do not call setup_timer() multiple times	2013-07-19 22:12:42 -07:00
caif	net: pass info struct via netdevice notifier	2013-05-28 13:11:01 -07:00
can	net: pass info struct via netdevice notifier	2013-05-28 13:11:01 -07:00
ceph	libceph: call r_unsafe_callback when unsafe reply is received	2013-07-03 15:32:58 -07:00
core	neigh: prevent overflowing params in /proc/sys/net/ipv4/neigh/	2013-07-26 14:22:10 -07:00
dcb
dccp
decnet	net: Convert uses of typedef ctl_table to struct ctl_table	2013-06-13 02:36:09 -07:00
dns_resolver	net: strict_strtoul is obsolete, use kstrtoul instead	2013-07-12 16:09:14 -07:00
dsa
ethernet	net: Fix sysfs_format_mac() code duplication.	2013-07-16 17:09:22 -07:00
ieee802154	net: pass info struct via netdevice notifier	2013-05-28 13:11:01 -07:00
ipv4	fib_trie: potential out of bounds access in trie_show_stats()	2013-07-24 16:05:14 -07:00
ipv6	ipv6: take rtnl_lock and mark mrt6 table as freed on namespace cleanup	2013-07-24 17:02:13 -07:00
ipx	net: pass info struct via netdevice notifier	2013-05-28 13:11:01 -07:00
irda	net/irda: fixed style issues in irlan_eth	2013-07-16 12:16:03 -07:00
iucv	net: delete __cpuinit usage from all net files	2013-07-14 19:36:58 -04:00
key	af_key: fix info leaks in notify messages	2013-06-26 15:15:54 -07:00
l2tp	l2tp: make datapath resilient to packet loss when sequence numbers enabled	2013-07-02 16:33:25 -07:00
lapb
llc	llc: Fix missing msg_namelen update in llc_ui_recvmsg()	2013-04-07 16:28:01 -04:00
mac80211	mac80211/minstrel: fix NULL pointer dereference issue	2013-07-16 17:48:14 +03:00
mac802154	Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net	2013-04-30 03:55:20 -04:00
mpls	MPLS: Add limited GSO support	2013-05-27 22:50:59 -07:00
netfilter	netfilter: xt_socket: fix broken v0 support	2013-07-15 11:15:21 +02:00
netlabel	net: pass info struct via netdevice notifier	2013-05-28 13:11:01 -07:00
netlink	genetlink: release cb_lock before requesting additional module	2013-07-27 22:19:20 -07:00
netrom	net: Convert uses of typedef ctl_table to struct ctl_table	2013-06-13 02:36:09 -07:00
nfc	NFC: llcp: Fix the well known services endianness	2013-06-14 13:45:10 +02:00
openvswitch	openvswitch: Add Kconfig dependency on GRE-DEMUX.	2013-07-01 13:19:43 -07:00
packet	Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net	2013-06-19 16:49:39 -07:00
phonet	net: Convert uses of typedef ctl_table to struct ctl_table	2013-06-13 02:36:09 -07:00
rds	net: Convert uses of typedef ctl_table to struct ctl_table	2013-06-13 02:36:09 -07:00
rfkill	Merge branch 'for-john' of git://git.kernel.org/pub/scm/linux/kernel/git/jberg/mac80211-next	2013-04-22 14:58:14 -04:00
rose	net: Convert uses of typedef ctl_table to struct ctl_table	2013-06-13 02:36:09 -07:00
rxrpc
sched	pkt_sched: sch_qfq: remove a source of high packet delay/jitter	2013-07-18 13:02:00 -07:00
sctp	net: sctp: confirm route during forward progress	2013-07-09 12:49:56 -07:00
sunrpc	Merge branch 'for-3.11' of git://linux-nfs.org/~bfields/linux	2013-07-17 13:43:55 -07:00
tipc	net/tipc: use %*phC to dump small buffers in hex form	2013-07-11 17:03:36 -07:00
unix	Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next	2013-07-09 18:24:39 -07:00
vmw_vsock	VSOCK: Fix VSOCK_HASH and VSOCK_CONN_HASH	2013-06-23 23:51:48 -07:00
wimax
wireless	nl80211: fix the setting of RSSI threshold value for mesh	2013-07-16 09:55:58 +03:00
x25	x25: Fix broken locking in ioctl error paths.	2013-07-01 18:15:25 -07:00
xfrm	Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/klassert/ipsec-next	2013-06-26 13:23:13 -07:00
compat.c	net: Unbreak compat_sys_{send,recv}msg	2013-06-06 11:52:14 -07:00
Kconfig	Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next	2013-07-09 18:24:39 -07:00
Makefile	MPLS: Add limited GSO support	2013-05-27 22:50:59 -07:00
nonet.c
socket.c	net: rename busy poll socket op and globals	2013-07-10 17:08:27 -07:00
sysctl_net.c