Eric Dumazet 93a33a584e bridge: fix lockdep splat ... Following lockdep splat was reported : [ 29.382286] =============================== [ 29.382315] [ INFO: suspicious RCU usage. ] [ 29.382344] 4.1.0-0.rc0.git11.1.fc23.x86_64 #1 Not tainted [ 29.382380] ------------------------------- [ 29.382409] net/bridge/br_private.h:626 suspicious rcu_dereference_check() usage! [ 29.382455] other info that might help us debug this: [ 29.382507] rcu_scheduler_active = 1, debug_locks = 0 [ 29.382549] 2 locks held by swapper/0/0: [ 29.382576] #0: (((&p->forward_delay_timer))){+.-...}, at: [<ffffffff81139f75>] call_timer_fn+0x5/0x4f0 [ 29.382660] #1: (&(&br->lock)->rlock){+.-...}, at: [<ffffffffa0450dc1>] br_forward_delay_timer_expired+0x31/0x140 [bridge] [ 29.382754] stack backtrace: [ 29.382787] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.1.0-0.rc0.git11.1.fc23.x86_64 #1 [ 29.382838] Hardware name: LENOVO 422916G/LENOVO, BIOS A1KT53AUS 04/07/2015 [ 29.382882] 0000000000000000 3ebfc20364115825 ffff880666603c48 ffffffff81892d4b [ 29.382943] 0000000000000000 ffffffff81e124e0 ffff880666603c78 ffffffff8110bcd7 [ 29.383004] ffff8800785c9d00 ffff88065485ac58 ffff880c62002800 ffff880c5fc88ac0 [ 29.383065] Call Trace: [ 29.383084] <IRQ> [<ffffffff81892d4b>] dump_stack+0x4c/0x65 [ 29.383130] [<ffffffff8110bcd7>] lockdep_rcu_suspicious+0xe7/0x120 [ 29.383178] [<ffffffffa04520f9>] br_fill_ifinfo+0x4a9/0x6a0 [bridge] [ 29.383225] [<ffffffffa045266b>] br_ifinfo_notify+0x11b/0x4b0 [bridge] [ 29.383271] [<ffffffffa0450d90>] ? br_hold_timer_expired+0x70/0x70 [bridge] [ 29.383320] [<ffffffffa0450de8>] br_forward_delay_timer_expired+0x58/0x140 [bridge] [ 29.383371] [<ffffffffa0450d90>] ? br_hold_timer_expired+0x70/0x70 [bridge] [ 29.383416] [<ffffffff8113a033>] call_timer_fn+0xc3/0x4f0 [ 29.383454] [<ffffffff81139f75>] ? call_timer_fn+0x5/0x4f0 [ 29.383493] [<ffffffff8110a90f>] ? lock_release_holdtime.part.29+0xf/0x200 [ 29.383541] [<ffffffffa0450d90>] ? br_hold_timer_expired+0x70/0x70 [bridge] [ 29.383587] [<ffffffff8113a6a4>] run_timer_softirq+0x244/0x490 [ 29.383629] [<ffffffff810b68cc>] __do_softirq+0xec/0x670 [ 29.383666] [<ffffffff810b70d5>] irq_exit+0x145/0x150 [ 29.383703] [<ffffffff8189f506>] smp_apic_timer_interrupt+0x46/0x60 [ 29.383744] [<ffffffff8189d523>] apic_timer_interrupt+0x73/0x80 [ 29.383782] <EOI> [<ffffffff816f131f>] ? cpuidle_enter_state+0x5f/0x2f0 [ 29.383832] [<ffffffff816f131b>] ? cpuidle_enter_state+0x5b/0x2f0 Problem here is that br_forward_delay_timer_expired() is a timer handler, calling br_ifinfo_notify() which assumes either rcu_read_lock() or RTNL are held. Simplest fix seems to add rcu read lock section. Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: Josh Boyer <jwboyer@fedoraproject.org> Reported-by: Dominick Grift <dac.override@gmail.com> Cc: Vlad Yasevich <vyasevich@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>		2015-05-22 16:23:56 -04:00
..
netfilter	netfilter: ensure number of counters is >0 in do_replace()	2015-05-20 13:46:49 +02:00
Kconfig	…
Makefile	netfilter: bridge: build br_nf_core only if required	2014-09-30 14:07:51 -04:00
br.c	net: bridge: add compile-time assert for cb struct size	2015-03-03 14:07:04 -05:00
br_device.c	netfilter: bridge: use rcu hook to resolve br_netfilter dependency	2015-03-10 15:03:02 +01:00
br_fdb.c	Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net	2015-02-09 14:35:57 -08:00
br_forward.c	netfilter: Pass socket pointer down through okfn().	2015-04-07 15:25:55 -04:00
br_if.c	bridge: reset bridge mtu after deleting an interface	2015-03-14 19:12:38 -04:00
br_input.c	netfilter: Pass socket pointer down through okfn().	2015-04-07 15:25:55 -04:00
br_ioctl.c	bridge: add space before '(/{', after ',', etc.	2013-12-19 19:27:26 -05:00
br_mdb.c	bridge/mdb: remove wrong use of NLM_F_MULTI	2015-04-29 14:59:16 -04:00
br_multicast.c	bridge: fix parsing of MLDv2 reports	2015-05-22 15:08:20 -04:00
br_netfilter.c	Revert "netfilter: bridge: query conntrack about skb dnat"	2015-05-20 13:51:25 +02:00
br_netlink.c	bridge/nl: remove wrong use of NLM_F_MULTI	2015-04-29 14:59:16 -04:00
br_nf_core.c	net: Remove protocol from struct dst_ops	2015-03-09 16:06:10 -04:00
br_private.h	bridge/nl: remove wrong use of NLM_F_MULTI	2015-04-29 14:59:16 -04:00
br_private_stp.h	net: 8021q/bluetooth/bridge/can/ceph: Remove extern from function prototypes	2013-10-19 19:12:11 -04:00
br_stp.c	bridge: call netdev_sw_port_stp_update when bridge port STP status changes	2014-12-02 20:01:22 -08:00
br_stp_bpdu.c	netfilter: Pass socket pointer down through okfn().	2015-04-07 15:25:55 -04:00
br_stp_if.c	net: bridge: add a br_set_state helper function	2014-10-01 22:03:50 -04:00
br_stp_timer.c	bridge: fix lockdep splat	2015-05-22 16:23:56 -04:00
br_sysfs_br.c	bridge: Add a default_pvid sysfs attribute	2014-10-05 21:21:36 -04:00
br_sysfs_if.c	bridge: Extend Proxy ARP design to allow optional rules for Wi-Fi	2015-03-05 14:52:23 -05:00
br_vlan.c	net: rename vlan_tx_* helpers since "tx" is misleading there	2015-01-13 17:51:08 -05:00