diff options
| author | dingtianhong <dingtianhong@huawei.com> | 2013-08-09 17:12:58 +0800 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2013-08-11 21:58:41 -0700 |
| commit | d4cca39d90fca21c04315095de5d0e734e839a8b (patch) | |
| tree | 3d787a6cc24478b6fcd773f0b650e156964679fa /net | |
| parent | 3c322a56b01695df15c70bfdc2d02e0ccd80654e (diff) | |
tipc: avoid possible deadlock while enable and disable bearer
We met lockdep warning when enable and disable the bearer for commands such as:
tipc-config -netid=1234 -addr=1.1.3 -be=eth:eth0
tipc-config -netid=1234 -addr=1.1.3 -bd=eth:eth0
---------------------------------------------------
[ 327.693595] ======================================================
[ 327.693994] [ INFO: possible circular locking dependency detected ]
[ 327.694519] 3.11.0-rc3-wwd-default #4 Tainted: G O
[ 327.694882] -------------------------------------------------------
[ 327.695385] tipc-config/5825 is trying to acquire lock:
[ 327.695754] (((timer))#2){+.-...}, at: [<ffffffff8105be80>] del_timer_sync+0x0/0xd0
[ 327.696018]
[ 327.696018] but task is already holding lock:
[ 327.696018] (&(&b_ptr->lock)->rlock){+.-...}, at: [<ffffffffa02be58d>] bearer_disable+ 0xdd/0x120 [tipc]
[ 327.696018]
[ 327.696018] which lock already depends on the new lock.
[ 327.696018]
[ 327.696018]
[ 327.696018] the existing dependency chain (in reverse order) is:
[ 327.696018]
[ 327.696018] -> #1 (&(&b_ptr->lock)->rlock){+.-...}:
[ 327.696018] [<ffffffff810b3b4d>] validate_chain+0x6dd/0x870
[ 327.696018] [<ffffffff810b40bb>] __lock_acquire+0x3db/0x670
[ 327.696018] [<ffffffff810b4453>] lock_acquire+0x103/0x130
[ 327.696018] [<ffffffff814d65b1>] _raw_spin_lock_bh+0x41/0x80
[ 327.696018] [<ffffffffa02c5d48>] disc_timeout+0x18/0xd0 [tipc]
[ 327.696018] [<ffffffff8105b92a>] call_timer_fn+0xda/0x1e0
[ 327.696018] [<ffffffff8105bcd7>] run_timer_softirq+0x2a7/0x2d0
[ 327.696018] [<ffffffff8105379a>] __do_softirq+0x16a/0x2e0
[ 327.696018] [<ffffffff81053a35>] irq_exit+0xd5/0xe0
[ 327.696018] [<ffffffff81033005>] smp_apic_timer_interrupt+0x45/0x60
[ 327.696018] [<ffffffff814df4af>] apic_timer_interrupt+0x6f/0x80
[ 327.696018] [<ffffffff8100b70e>] arch_cpu_idle+0x1e/0x30
[ 327.696018] [<ffffffff810a039d>] cpu_idle_loop+0x1fd/0x280
[ 327.696018] [<ffffffff810a043e>] cpu_startup_entry+0x1e/0x20
[ 327.696018] [<ffffffff81031589>] start_secondary+0x89/0x90
[ 327.696018]
[ 327.696018] -> #0 (((timer))#2){+.-...}:
[ 327.696018] [<ffffffff810b33fe>] check_prev_add+0x43e/0x4b0
[ 327.696018] [<ffffffff810b3b4d>] validate_chain+0x6dd/0x870
[ 327.696018] [<ffffffff810b40bb>] __lock_acquire+0x3db/0x670
[ 327.696018] [<ffffffff810b4453>] lock_acquire+0x103/0x130
[ 327.696018] [<ffffffff8105bebd>] del_timer_sync+0x3d/0xd0
[ 327.696018] [<ffffffffa02c5855>] tipc_disc_delete+0x15/0x30 [tipc]
[ 327.696018] [<ffffffffa02be59f>] bearer_disable+0xef/0x120 [tipc]
[ 327.696018] [<ffffffffa02be74f>] tipc_disable_bearer+0x2f/0x60 [tipc]
[ 327.696018] [<ffffffffa02bfb32>] tipc_cfg_do_cmd+0x2e2/0x550 [tipc]
[ 327.696018] [<ffffffffa02c8c79>] handle_cmd+0x49/0xe0 [tipc]
[ 327.696018] [<ffffffff8143e898>] genl_family_rcv_msg+0x268/0x340
[ 327.696018] [<ffffffff8143ed30>] genl_rcv_msg+0x70/0xd0
[ 327.696018] [<ffffffff8143d4c9>] netlink_rcv_skb+0x89/0xb0
[ 327.696018] [<ffffffff8143e617>] genl_rcv+0x27/0x40
[ 327.696018] [<ffffffff8143d21e>] netlink_unicast+0x15e/0x1b0
[ 327.696018] [<ffffffff8143ddcf>] netlink_sendmsg+0x22f/0x400
[ 327.696018] [<ffffffff813f7836>] __sock_sendmsg+0x66/0x80
[ 327.696018] [<ffffffff813f7957>] sock_aio_write+0x107/0x120
[ 327.696018] [<ffffffff8117f76d>] do_sync_write+0x7d/0xc0
[ 327.696018] [<ffffffff8117fc56>] vfs_write+0x186/0x190
[ 327.696018] [<ffffffff811803e0>] SyS_write+0x60/0xb0
[ 327.696018] [<ffffffff814de852>] system_call_fastpath+0x16/0x1b
[ 327.696018]
[ 327.696018] other info that might help us debug this:
[ 327.696018]
[ 327.696018] Possible unsafe locking scenario:
[ 327.696018]
[ 327.696018] CPU0 CPU1
[ 327.696018] ---- ----
[ 327.696018] lock(&(&b_ptr->lock)->rlock);
[ 327.696018] lock(((timer))#2);
[ 327.696018] lock(&(&b_ptr->lock)->rlock);
[ 327.696018] lock(((timer))#2);
[ 327.696018]
[ 327.696018] *** DEADLOCK ***
[ 327.696018]
[ 327.696018] 5 locks held by tipc-config/5825:
[ 327.696018] #0: (cb_lock){++++++}, at: [<ffffffff8143e608>] genl_rcv+0x18/0x40
[ 327.696018] #1: (genl_mutex){+.+.+.}, at: [<ffffffff8143ed66>] genl_rcv_msg+0xa6/0xd0
[ 327.696018] #2: (config_mutex){+.+.+.}, at: [<ffffffffa02bf889>] tipc_cfg_do_cmd+0x39/ 0x550 [tipc]
[ 327.696018] #3: (tipc_net_lock){++.-..}, at: [<ffffffffa02be738>] tipc_disable_bearer+ 0x18/0x60 [tipc]
[ 327.696018] #4: (&(&b_ptr->lock)->rlock){+.-...}, at: [<ffffffffa02be58d>] bearer_disable+0xdd/0x120 [tipc]
[ 327.696018]
[ 327.696018] stack backtrace:
[ 327.696018] CPU: 2 PID: 5825 Comm: tipc-config Tainted: G O 3.11.0-rc3-wwd- default #4
[ 327.696018] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2007
[ 327.696018] 00000000ffffffff ffff880037fa77a8 ffffffff814d03dd 0000000000000000
[ 327.696018] ffff880037fa7808 ffff880037fa77e8 ffffffff810b1c4f 0000000037fa77e8
[ 327.696018] ffff880037fa7808 ffff880037e4db40 0000000000000000 ffff880037e4e318
[ 327.696018] Call Trace:
[ 327.696018] [<ffffffff814d03dd>] dump_stack+0x4d/0xa0
[ 327.696018] [<ffffffff810b1c4f>] print_circular_bug+0x10f/0x120
[ 327.696018] [<ffffffff810b33fe>] check_prev_add+0x43e/0x4b0
[ 327.696018] [<ffffffff810b3b4d>] validate_chain+0x6dd/0x870
[ 327.696018] [<ffffffff81087a28>] ? sched_clock_cpu+0xd8/0x110
[ 327.696018] [<ffffffff810b40bb>] __lock_acquire+0x3db/0x670
[ 327.696018] [<ffffffff810b4453>] lock_acquire+0x103/0x130
[ 327.696018] [<ffffffff8105be80>] ? try_to_del_timer_sync+0x70/0x70
[ 327.696018] [<ffffffff8105bebd>] del_timer_sync+0x3d/0xd0
[ 327.696018] [<ffffffff8105be80>] ? try_to_del_timer_sync+0x70/0x70
[ 327.696018] [<ffffffffa02c5855>] tipc_disc_delete+0x15/0x30 [tipc]
[ 327.696018] [<ffffffffa02be59f>] bearer_disable+0xef/0x120 [tipc]
[ 327.696018] [<ffffffffa02be74f>] tipc_disable_bearer+0x2f/0x60 [tipc]
[ 327.696018] [<ffffffffa02bfb32>] tipc_cfg_do_cmd+0x2e2/0x550 [tipc]
[ 327.696018] [<ffffffff81218783>] ? security_capable+0x13/0x20
[ 327.696018] [<ffffffffa02c8c79>] handle_cmd+0x49/0xe0 [tipc]
[ 327.696018] [<ffffffff8143e898>] genl_family_rcv_msg+0x268/0x340
[ 327.696018] [<ffffffff8143ed30>] genl_rcv_msg+0x70/0xd0
[ 327.696018] [<ffffffff8143ecc0>] ? genl_lock+0x20/0x20
[ 327.696018] [<ffffffff8143d4c9>] netlink_rcv_skb+0x89/0xb0
[ 327.696018] [<ffffffff8143e608>] ? genl_rcv+0x18/0x40
[ 327.696018] [<ffffffff8143e617>] genl_rcv+0x27/0x40
[ 327.696018] [<ffffffff8143d21e>] netlink_unicast+0x15e/0x1b0
[ 327.696018] [<ffffffff81289d7c>] ? memcpy_fromiovec+0x6c/0x90
[ 327.696018] [<ffffffff8143ddcf>] netlink_sendmsg+0x22f/0x400
[ 327.696018] [<ffffffff813f7836>] __sock_sendmsg+0x66/0x80
[ 327.696018] [<ffffffff813f7957>] sock_aio_write+0x107/0x120
[ 327.696018] [<ffffffff813fe29c>] ? release_sock+0x8c/0xa0
[ 327.696018] [<ffffffff8117f76d>] do_sync_write+0x7d/0xc0
[ 327.696018] [<ffffffff8117fa24>] ? rw_verify_area+0x54/0x100
[ 327.696018] [<ffffffff8117fc56>] vfs_write+0x186/0x190
[ 327.696018] [<ffffffff811803e0>] SyS_write+0x60/0xb0
[ 327.696018] [<ffffffff814de852>] system_call_fastpath+0x16/0x1b
-----------------------------------------------------------------------
The problem is that the tipc_link_delete() will cancel the timer disc_timeout() when
the b_ptr->lock is hold, but the disc_timeout() still call b_ptr->lock to finish the
work, so the dead lock occurs.
We should unlock the b_ptr->lock when del the disc_timeout().
Remove link_timeout() still met the same problem, the patch:
http://article.gmane.org/gmane.network.tipc.general/4380
fix the problem, so no need to send patch for fix link_timeout() deadlock warming.
Signed-off-by: Wang Weidong <wangweidong1@huawei.com>
Signed-off-by: Ding Tianhong <dingtianhong@huawei.com>
Acked-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net')
| -rw-r--r-- | net/tipc/bearer.c | 9 |
1 files changed, 7 insertions, 2 deletions
diff --git a/net/tipc/bearer.c b/net/tipc/bearer.c index cb29ef7ba2f..609c30c8081 100644 --- a/net/tipc/bearer.c +++ b/net/tipc/bearer.c @@ -460,6 +460,7 @@ static void bearer_disable(struct tipc_bearer *b_ptr) { struct tipc_link *l_ptr; struct tipc_link *temp_l_ptr; + struct tipc_link_req *temp_req; pr_info("Disabling bearer <%s>\n", b_ptr->name); spin_lock_bh(&b_ptr->lock); @@ -468,9 +469,13 @@ static void bearer_disable(struct tipc_bearer *b_ptr) list_for_each_entry_safe(l_ptr, temp_l_ptr, &b_ptr->links, link_list) { tipc_link_delete(l_ptr); } - if (b_ptr->link_req) - tipc_disc_delete(b_ptr->link_req); + temp_req = b_ptr->link_req; + b_ptr->link_req = NULL; spin_unlock_bh(&b_ptr->lock); + + if (temp_req) + tipc_disc_delete(temp_req); + memset(b_ptr, 0, sizeof(struct tipc_bearer)); } |