2020-10-27 14:53:49

by kernel test robot

[permalink] [raw]
Subject: [selftests] f2ff7f11f9: WARNING:suspicious_RCU_usage

Greeting,

FYI, we noticed the following commit (built with gcc-9):

commit: f2ff7f11f9a74842245db52d685bf9bc7ac2c4b1 ("selftests: mptcp: add ADD_ADDR IPv6 test cases")
https://github.com/multipath-tcp/mptcp_net-next.git export


in testcase: kernel-selftests
version: kernel-selftests-x86_64-b5a583fb-1_20201015
with following parameters:

group: kselftests-mptcp
ucode: 0xdc

test-description: The kernel contains a set of "self tests" under the tools/testing/selftests/ directory. These are intended to be small unit tests to exercise individual code paths in the kernel.
test-url: https://www.kernel.org/doc/Documentation/kselftest.txt


on test machine: 8 threads Intel(R) Core(TM) i7-6700 CPU @ 3.40GHz with 28G memory

caused below changes (please refer to attached dmesg/kmsg for entire log/backtrace):



If you fix the issue, kindly add following tag
Reported-by: kernel test robot <[email protected]>


[ 229.193156] WARNING: suspicious RCU usage
[ 229.197723] 5.9.0-13449-gf2ff7f11f9a7 #1 Tainted: G I
[ 229.204734] -----------------------------
[ 229.209277] include/net/sock.h:1915 suspicious rcu_dereference_check() usage!
[ 229.216990]
[ 229.216990] other info that might help us debug this:
[ 229.216990]
[ 229.226621]
[ 229.226621] rcu_scheduler_active = 2, debug_locks = 1
[ 229.234252] 3 locks held by kworker/2:1/64:
[ 229.239016] #0: ffff888100054938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x1be/0x580
[ 229.249063] #1: ffffc9000029fe58 ((work_completion)(&msk->work)){+.+.}-{0:0}, at: process_one_work+0x1be/0x580
[ 229.259745] #2: ffff888750f14c60 (sk_lock-AF_INET6){+.+.}-{0:0}, at: mptcp_worker+0x47/0x900
[ 229.268913]
[ 229.268913] stack backtrace:
[ 229.274409] CPU: 2 PID: 64 Comm: kworker/2:1 Tainted: G I 5.9.0-13449-gf2ff7f11f9a7 #1
[ 229.284150] Hardware name: Dell Inc. OptiPlex 7040/0Y7WYT, BIOS 1.2.8 01/26/2016
[ 229.292076] Workqueue: events mptcp_worker
[ 229.296740] Call Trace:
[ 229.299765] dump_stack+0x8d/0xb5
[ 229.303631] __sk_dst_check+0xa7/0xe0
[ 229.307860] inet6_csk_route_socket+0x1a5/0x440
[ 229.312963] ? inet6_csk_xmit+0x58/0x240
[ 229.317401] inet6_csk_xmit+0x58/0x240
[ 229.321703] __tcp_transmit_skb+0x571/0xc80
[ 229.326421] mptcp_pm_check_send_dedicated_add_addr_packet+0x4c/0x80
[ 229.333929] mptcp_pm_create_subflow_or_signal_addr+0x659/0x700
[ 229.340370] mptcp_worker+0x68a/0x900
[ 229.344553] process_one_work+0x23e/0x580
[ 229.349134] worker_thread+0x50/0x3c0
[ 229.353324] ? process_one_work+0x580/0x580
[ 229.358076] kthread+0x133/0x180
[ 229.361883] ? kthread_park+0xa0/0xa0
[ 229.366100] ret_from_fork+0x22/0x30
[ 234.629864] # 19 unused signal address IPv6 syn[ ok ] - synack[ ok ] - ack[ ok ]
[ 234.629869]
[ 234.646748] # add[fail] got 0 ADD_ADDR[s] expected 1
[ 234.646753]
[ 234.663869] # - echo [fail] got 0 ADD_ADDR echo[s] expected 1
[ 234.663874]
[ 234.672854] # Server ns stats
[ 234.672858]
[ 234.680940] # MPTcpExtMPCapableSYNRX 1 0.0
[ 234.680945]
[ 234.691230] # MPTcpExtMPCapableACKRX 1 0.0
[ 234.691234]
[ 234.701766] # MPTcpExtMPTCPRetrans 5 0.0
[ 234.701770]
[ 234.712131] # MPTcpExtDuplicateData 1 0.0
[ 234.712135]
[ 234.721565] # Client ns stats
[ 234.721569]
[ 234.728499] # MPTcpExtMPTCPRetrans 1 0.0
[ 234.728503]
[ 234.739086] # MPTcpExtDuplicateData 5 0.0
[ 234.739090]
[ 234.840939] IPv6: ADDRCONF(NETDEV_CHANGE): ns1eth1: link becomes ready
[ 234.878710] IPv6: ADDRCONF(NETDEV_CHANGE): ns1eth2: link becomes ready
[ 234.916540] IPv6: ADDRCONF(NETDEV_CHANGE): ns1eth3: link becomes ready
[ 234.954915] IPv6: ADDRCONF(NETDEV_CHANGE): ns1eth4: link becomes ready
[ 235.841647] IPv6: ADDRCONF(NETDEV_CHANGE): ns2eth1: link becomes ready
[ 241.248714] # 20 single address IPv6 syn[ ok ] - synack[ ok ] - ack[ ok ]
[ 241.248720]
[ 241.274168] # add[ ok ] - echo [ ok ]
[ 241.274174]
[ 241.397805] IPv6: ADDRCONF(NETDEV_CHANGE): ns1eth1: link becomes ready
[ 241.435917] IPv6: ADDRCONF(NETDEV_CHANGE): ns1eth2: link becomes ready
[ 241.474418] IPv6: ADDRCONF(NETDEV_CHANGE): ns1eth3: link becomes ready
[ 241.512504] IPv6: ADDRCONF(NETDEV_CHANGE): ns1eth4: link becomes ready
[ 242.433629] IPv6: ADDRCONF(NETDEV_CHANGE): ns2eth1: link becomes ready
[ 247.824119] # 21 signal address, ADD_ADDR6 timeout syn[ ok ] - synack[ ok ] - ack[ ok ]
[ 247.824125]
[ 247.850751] # add[ ok ] - echo [ ok ]
[ 247.850756]
[ 247.976931] IPv6: ADDRCONF(NETDEV_CHANGE): ns1eth1: link becomes ready
[ 248.014492] IPv6: ADDRCONF(NETDEV_CHANGE): ns1eth2: link becomes ready
[ 248.052311] IPv6: ADDRCONF(NETDEV_CHANGE): ns1eth3: link becomes ready
[ 248.090896] IPv6: ADDRCONF(NETDEV_CHANGE): ns1eth4: link becomes ready
[ 248.961779] IPv6: ADDRCONF(NETDEV_CHANGE): ns2eth1: link becomes ready
[ 254.389366] # 22 remove single address IPv6 syn[ ok ] - synack[ ok ] - ack[ ok ]
[ 254.389372]
[ 254.414626] # add[ ok ] - echo [ ok ]
[ 254.414631]
[ 254.439555] # rm [ ok ] - sf [ ok ]
[ 254.439560]
[ 254.563953] IPv6: ADDRCONF(NETDEV_CHANGE): ns1eth1: link becomes ready
[ 254.601725] IPv6: ADDRCONF(NETDEV_CHANGE): ns1eth2: link becomes ready
[ 254.639744] IPv6: ADDRCONF(NETDEV_CHANGE): ns1eth3: link becomes ready
[ 254.677730] IPv6: ADDRCONF(NETDEV_CHANGE): ns1eth4: link becomes ready
[ 255.553706] IPv6: ADDRCONF(NETDEV_CHANGE): ns2eth1: link becomes ready
[ 260.988434] # 23 remove subflow and signal IPv6 syn[ ok ] - synack[ ok ] - ack[ ok ]
[ 260.988440]
[ 261.014261] # add[ ok ] - echo [ ok ]
[ 261.014267]
[ 261.038447] # rm [ ok ] - sf [ ok ]
[ 261.038452]
[ 261.162474] IPv6: ADDRCONF(NETDEV_CHANGE): ns1eth1: link becomes ready
[ 261.200463] IPv6: ADDRCONF(NETDEV_CHANGE): ns1eth2: link becomes ready
[ 261.238952] IPv6: ADDRCONF(NETDEV_CHANGE): ns1eth3: link becomes ready
[ 261.276707] IPv6: ADDRCONF(NETDEV_CHANGE): ns1eth4: link becomes ready
[ 262.145701] IPv6: ADDRCONF(NETDEV_CHANGE): ns2eth1: link becomes ready


To reproduce:

git clone https://github.com/intel/lkp-tests.git
cd lkp-tests
bin/lkp install job.yaml # job file is attached in this email
bin/lkp run job.yaml



Thanks,
lkp


Attachments:
(No filename) (6.69 kB)
config-5.9.0-13449-gf2ff7f11f9a7 (214.81 kB)
job-script (6.53 kB)
dmesg (208.30 kB)
kernel-selftests (51.77 kB)
job.yaml (5.62 kB)
reproduce (175.00 B)
Download all attachments

2020-10-28 16:15:55

by Matthieu Baerts

[permalink] [raw]
Subject: Re: [MPTCP] [selftests] f2ff7f11f9: WARNING:suspicious_RCU_usage

Hi all,

On 27/10/2020 14:16, kernel test robot wrote:
> Greeting,
>
> FYI, we noticed the following commit (built with gcc-9):
>
> commit: f2ff7f11f9a74842245db52d685bf9bc7ac2c4b1 ("selftests: mptcp: add ADD_ADDR IPv6 test cases")
> https://github.com/multipath-tcp/mptcp_net-next.git export

Thanks for the maintainer of the kernel test robot at Intel for this bug
report!

FYI, this was already reported earlier:

https://github.com/multipath-tcp/mptcp_net-next/issues/102

And Geliang is working on a fix (a v2 is available).

Cheers,
Matt
--
Tessares | Belgium | Hybrid Access Solutions
http://www.tessares.net

2020-10-28 21:41:56

by Li, Philip

[permalink] [raw]
Subject: Re: [MPTCP] Re: [selftests] f2ff7f11f9: WARNING:suspicious_RCU_usage

On Tue, Oct 27, 2020 at 04:07:28PM +0100, Matthieu Baerts wrote:
> Hi all,
>
> On 27/10/2020 14:16, kernel test robot wrote:
> > Greeting,
> >
> > FYI, we noticed the following commit (built with gcc-9):
> >
> > commit: f2ff7f11f9a74842245db52d685bf9bc7ac2c4b1 ("selftests: mptcp: add ADD_ADDR IPv6 test cases")
> > https://github.com/multipath-tcp/mptcp_net-next.git export
>
> Thanks for the maintainer of the kernel test robot at Intel for this bug
> report!
thanks, you are welcome!

>
> FYI, this was already reported earlier:
>
> https://github.com/multipath-tcp/mptcp_net-next/issues/102
Thanks for the info, we didn't notice this. We will take a look
of reported issues in future to avoid duplicated report.

>
> And Geliang is working on a fix (a v2 is available).
>
> Cheers,
> Matt
> --
> Tessares | Belgium | Hybrid Access Solutions
> http://www.tessares.net
> _______________________________________________
> mptcp mailing list -- [email protected]
> To unsubscribe send an email to [email protected]

2020-10-29 02:40:46

by Matthieu Baerts

[permalink] [raw]
Subject: Re: [MPTCP] Re: [selftests] f2ff7f11f9: WARNING:suspicious_RCU_usage

Hi Philip,

On 28/10/2020 00:00, Philip Li wrote:
> On Tue, Oct 27, 2020 at 04:07:28PM +0100, Matthieu Baerts wrote:
>> FYI, this was already reported earlier:
>>
>> https://github.com/multipath-tcp/mptcp_net-next/issues/102
> Thanks for the info, we didn't notice this. We will take a look
> of reported issues in future to avoid duplicated report.

Thanks but I also hope we would not have a lot of other similar issues :)
In this case, duplicated report is not a big deal!

Cheers,
Matt
--
Tessares | Belgium | Hybrid Access Solutions
http://www.tessares.net