From: "Shi, Yang" <yang.shi@linaro.org>
To: "David S. Miller" <davem@davemloft.net>, hannes@stressinduktion.org
Cc: LKML <linux-kernel@vger.kernel.org>,
Network Development <netdev@vger.kernel.org>
Subject: Warning triggered by lockdep checks for sock_owned_by_user on linux-next-20160420
Date: Fri, 22 Apr 2016 21:02:10 -0700 [thread overview]
Message-ID: <571AF3C2.3010509@linaro.org> (raw)
Hi David,
When I ran some test on a nfs mounted rootfs, I got the below warning
with LOCKDEP enabled on linux-next-20160420:
WARNING: CPU: 9 PID: 0 at include/net/sock.h:1408
udp_queue_rcv_skb+0x3d0/0x660
Modules linked in:
CPU: 9 PID: 0 Comm: swapper/9 Tainted: G D
4.6.0-rc4-next-20160420-WR7.0.0.0_standard+ #6
Hardware name: Intel Corporation S5520HC/S5520HC, BIOS
S5500.86B.01.10.0025.030220091519 03/02/2009
0000000000000000 ffff88066fd03a70 ffffffff8155855f 0000000000000000
0000000000000000 ffff88066fd03ab0 ffffffff81062803 0000058061318ec8
ffff88065d1e39c0 ffff880661318e40 0000000000000000 ffff880661318ec8
Call Trace:
<IRQ> [<ffffffff8155855f>] dump_stack+0x67/0x98
Checking out fil [<ffffffff81062803>] __warn+0xd3/0xf0
[<ffffffff810628ed>] warn_slowpath_null+0x1d/0x20
[<ffffffff81aa48f0>] udp_queue_rcv_skb+0x3d0/0x660
[<ffffffff81aa505c>] __udp4_lib_rcv+0x4dc/0xc00
[<ffffffff81aa5b5a>] udp_rcv+0x1a/0x20
[<ffffffff81a728a1>] ip_local_deliver_finish+0xd1/0x2e0
es: 57% (30585/ [<ffffffff81a7280f>] ? ip_local_deliver_finish+0x3f/0x2e0
[<ffffffff81a73262>] ip_local_deliver+0xc2/0xd0
[<ffffffff81a72c92>] ip_rcv_finish+0x1e2/0x5a0
[<ffffffff81a7354c>] ip_rcv+0x2dc/0x410
[<ffffffff81a20a32>] ? __pskb_pull_tail+0x82/0x400
[<ffffffff81a2e188>] __netif_receive_skb_core+0x3a8/0xa80
[<ffffffff81a30b9b>] ? netif_receive_skb_internal+0x1b/0xf0
[<ffffffff81a30b3d>] __netif_receive_skb+0x1d/0x60
[<ffffffff81a30bd5>] netif_receive_skb_internal+0x55/0xf0
[<ffffffff81a30b9b>] ? netif_receive_skb_internal+0x1b/0xf0
[<ffffffff81a31b52>] napi_gro_receive+0xc2/0x180
[<ffffffff8187188a>] igb_poll+0x5ea/0xdf0
[<ffffffff81a32b9c>] net_rx_action+0x15c/0x3d0
[<ffffffff81c668c1>] __do_softirq+0x161/0x413
[<ffffffff810683a1>] irq_exit+0xd1/0x110
[<ffffffff81c664d2>] do_IRQ+0x62/0xf0
[<ffffffff81c6474e>] common_interrupt+0x8e/0x8e
<EOI> [<ffffffff8198d9c6>] ? cpuidle_enter_state+0xc6/0x290
[<ffffffff8198dbc7>] cpuidle_enter+0x17/0x20
[<ffffffff810aa963>] call_cpuidle+0x33/0x50
[<ffffffff810aace9>] cpu_startup_entry+0x229/0x3b0
[<ffffffff810407e4>] start_secondary+0x144/0x150
---[ end trace ba508c424f0d52bf ]---
The warning is triggered by commit
fafc4e1ea1a4c1eb13a30c9426fb799f5efacbc3 ("sock: tigthen lockdep checks
for sock_owned_by_user"), which checks if slock is held before locking
"owned".
It looks good to lock_sock which is just called lock_sock_nested. But,
bh_lock_sock is different, which just calls spin_lock so it doesn't
touch dep_map then the check will fail even though it is locked.
So, I'm wondering what a right fix for it should be:
1. Replace bh_lock_sock to bh_lock_sock_nested in the protocols
implementation, but there are a lot places calling it.
2. Just like lock_sock, just call bh_lock_sock_nested instead of spin_lock.
Or the both approach is wrong or not ideal?
Thanks,
Yang
next reply other threads:[~2016-04-23 4:02 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-04-23 4:02 Shi, Yang [this message]
2016-04-23 4:50 ` Warning triggered by lockdep checks for sock_owned_by_user on linux-next-20160420 Eric Dumazet
2016-04-25 17:32 ` Shi, Yang
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