Net/core/dev.c exception

Hi there,

just found following exception in my log and i hope someone can figure out what that is:

[404665.426936] ------------[ cut here ]------------
[404665.426955] WARNING: CPU: 0 PID: 0 at net/core/dev.c:4928 net_rx_action+0x268/0x308()
[404665.426965] Modules linked in: qcserial option iptable_nat ath9k usb_wwan rndis_host qmi_wwan pppoe nf_nat_pptp nf_nat_ipv4 nf_nat_amanda nf_conntrack_pptp nf_conntrack_netlink nf_conntrack_ipv6 nf_conntrack_ipv4 nf_conntrack_amanda ipt_REJECT ipt_MASQUERADE ebtable_nat ebtable_filter ebtable_broute cdc_ether ath9k_common armada_thermal xt_time xt_tcpudp xt_tcpmss xt_statistic xt_state xt_recent xt_nat xt_multiport xt_mark xt_mac xt_limit xt_length xt_id xt_hl xt_helper xt_ecn xt_dscp xt_conntrack xt_connmark xt_connlimit xt_connbytes xt_comment xt_TCPMSS xt_REDIRECT xt_LOG xt_HL xt_DSCP xt_CT xt_CLASSIFY usbserial usbnet ums_usbat ums_sddr55 ums_sddr09 ums_karma ums_jumpshot ums_isd200 ums_freecom ums_datafab ums_cypress ums_alauda ts_kmp ts_fsm ts_bm thermal_sys pppox ppp_mppe ppp_async nfnetlink nf_reject_ipv4 nf_nat_tftp nf_nat_snmp_basic nf_nat_sip nf_nat_redirect nf_nat_proto_gre nf_nat_masquerade_ipv4 nf_nat_irc nf_nat_h323 nf_nat_ftp nf_nat nf_log_ipv4 nf_defrag_ipv6 nf_defrag_ipv4 nf_conntrack_tftp nf_conntrack_snmp nf_conntrack_sip nf_conntrack_rtcache nf_conntrack_proto_gre nf_conntrack_irc nf_conntrack_h323 nf_conntrack_ftp nf_conntrack_broadcast nf_conntrack mvsdio iptable_raw iptable_mangle iptable_filter ipt_ECN ip_tables hwmon ebtables ebt_vlan ebt_stp ebt_redirect ebt_pkttype ebt_mark_m ebt_mark ebt_limit ebt_among ebt_802_3 crc_ccitt cdc_wdm ath9k_hw fuse sch_teql sch_tbf sch_sfq sch_red sch_prio sch_pie sch_netem sch_htb sch_gred sch_fq sch_dsmark sch_codel em_text em_nbyte em_meta em_cmp cls_basic act_vlan act_police act_pedit act_nat act_ipt act_gact act_csum act_bpf act_skbedit act_mirred em_u32 cls_u32 cls_tcindex cls_flow cls_route cls_fw sch_hfsc sch_ingress ath10k_pci ath10k_core ath mac80211 cfg80211 compat ledtrig_usbdev ledtrig_oneshot xt_LED ledtrig_morse ledtrig_heartbeat ledtrig_gpio cryptodev ip6t_REJECT nf_reject_ipv6 nf_log_ipv6 nf_log_common ip6table_raw ip6table_mangle ip6table_filter ip6_tables x_tables pppoatm ppp_generic slhc nfsd nfsv3 msdos ip_gre gre ifb sit ip6_tunnel tunnel6 tunnel4 ip_tunnel tun snd_compress snd_pcm_oss snd_mixer_oss snd_pcm snd_timer snd_rawmidi snd_seq_device snd_hwdep snd input_core soundcore rxkad vfat fat udf crc_itu_t ntfs nfs_layout_nfsv41_files nfsv4 nfs auth_rpcgss oid_registry lockd sunrpc grace minix isofs hfsplus hfs cramfs configfs cifs autofs4 kafs af_rxrpc dns_resolver dm_crypt dm_mirror dm_region_hash dm_log dm_mod br2684 atm multipath fscache raid456 async_raid6_recov async_pq async_xor async_memcpy async_tx raid10 raid1 raid0 linear md_mod nls_utf8 nls_koi8_r nls_cp1255 nls_iso8859_6 nls_iso8859_2 nls_iso8859_15 nls_iso8859_13 nls_iso8859_1 nls_cp932 nls_cp866 nls_cp864 nls_cp862 nls_cp852 nls_cp850 nls_cp775 nls_cp437 nls_cp1251 nls_cp1250 xts algif_skcipher algif_hash af_alg sha512_generic sha256_generic sha1_generic seqiv jitterentropy_rng drbg pcbc md5 md4 marvell_cesa hmac gf128mul fcrypt ecb des_generic ctr cmac ccm cbc authenc xhci_plat_hcd xhci_pci xhci_hcd uhci_hcd ledtrig_transient ahci_platform uas xfs libcrc32c jfs f2fs exfat mii aead crypto_null
[404665.427323] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.4.176-7bc33afbb1b35f5830b2b1b42c9cd8a0-0 #1
[404665.427327] Hardware name: Marvell Armada 380/385 (Device Tree)
[404665.427330] Backtrace: 
[404665.427340] [<c001c50c>] (dump_backtrace) from [<c001c74c>] (show_stack+0x18/0x1c)
[404665.427343]  r6:00000000 r5:60000113 r4:c0770d68 r3:00000000
[404665.427357] [<c001c734>] (show_stack) from [<c02ff974>] (dump_stack+0x98/0xac)
[404665.427365] [<c02ff8dc>] (dump_stack) from [<c0029254>] (warn_slowpath_common+0x8c/0xbc)
[404665.427367]  r6:00001340 r5:c04a7f34 r4:00000000 r3:00000006
[404665.427377] [<c00291c8>] (warn_slowpath_common) from [<c0029328>] (warn_slowpath_null+0x24/0x2c)
[404665.427380]  r8:c075fe08 r7:0000012c r6:00000040 r5:00000081 r4:ec9dd220
[404665.427391] [<c0029304>] (warn_slowpath_null) from [<c04a7f34>] (net_rx_action+0x268/0x308)
[404665.427399] [<c04a7ccc>] (net_rx_action) from [<c002c7c8>] (__do_softirq+0x114/0x260)
[404665.427401]  r10:00000000 r9:00000003 r8:00000100 r7:c075e000 r6:40000003 r5:c0760080
[404665.427410]  r4:c076008c
[404665.427416] [<c002c6b4>] (__do_softirq) from [<c002cba0>] (irq_exit+0x80/0xb8)
[404665.427419]  r10:c075ff80 r9:f0803100 r8:ee808000 r7:00000001 r6:00000000 r5:00000000
[404665.427427]  r4:c0758ff0
[404665.427434] [<c002cb20>] (irq_exit) from [<c0068ad8>] (__handle_domain_irq+0x68/0xb8)
[404665.427437]  r4:c0758ff0 r3:f0802100
[404665.427445] [<c0068a70>] (__handle_domain_irq) from [<c0009550>] (gic_handle_irq+0x50/0x94)
[404665.427447]  r8:c075ff10 r7:f080210c r6:c0761038 r5:c07711bc r4:f0802100 r3:c075ff10
[404665.427458] [<c0009500>] (gic_handle_irq) from [<c000a694>] (__irq_svc+0x54/0x70)
[404665.427462] Exception stack(0xc075ff10 to 0xc075ff58)
[404665.427467] ff00:                                     00000001 00000000 c075ff70 c000b520
[404665.427472] ff20: c075e000 c0760498 c0649734 00000000 00000000 c075b118 c075ff80 c075ff6c
[404665.427477] ff40: c075ff70 c075ff60 c00192fc c0019300 60000013 ffffffff
[404665.427480]  r9:c075b118 r8:00000000 r7:c075ff44 r6:ffffffff r5:60000013 r4:c0019300
[404665.427498] [<c00192c0>] (arch_cpu_idle) from [<c00605e0>] (default_idle_call+0x28/0x34)
[404665.427504] [<c00605b8>] (default_idle_call) from [<c0060738>] (cpu_startup_entry+0x14c/0x22c)
[404665.427510] [<c00605ec>] (cpu_startup_entry) from [<c000eca8>] (rest_init+0x80/0x84)
[404665.427513]  r7:c07603c0
[404665.427522] [<c000ec28>] (rest_init) from [<c0715de0>] (start_kernel+0x460/0x46c)
[404665.427529] [<c0715980>] (start_kernel) from [<0000807c>] (0x807c)
[404665.427532] ---[ end trace cff0487b4344a7da ]---

Its an Turris Omnia running with 3.11.3. If anything else needed just ask for it :slight_smile:
I didn’t recognized any downtime or so. Still running “normal”.

Got a USB LTE/WWAN modem installed?

Hi, nope, only thing that is attached is a USB Memory Stick for statistic data of YaMon.
Ah and i am using a SFP Fiber Adapter that is may handeled internally as USB device.

From the log posted I cannot lay a pointer at the cause but with the IRQ issues cited I would reckon that one of the USB devices is causing it.

Perhaps you could try disconnecting one or the other and reboot and see what the logs are showing then.

Hi again,
as you can see with the timestamp it is not occuring right after reboot. I just saw it the first time there. Anyway reboot worked without any issues. USB Stick is working normal.
But as this exception is not normal i just wanted to post it, if it is known/worth to fix. I can’t improve the error message either if it is not helpfull, but maybe also a point where to do improvements.
Thanks anyway that you try to help :slight_smile:

If that is the cause then it might indicate a SFP sync issue.

Some technical info about net_rx_action

http://www.embeddedlinux.org.cn/linux_net/0596002556/understandlni-CHP-10-SECT-7.html

Alright. What can i do against it?

I am not knowable enough to resolve such (kernel) issue, maybe some other forum user is.

Else, I would monitor the logs and see whether the issue is repeated and if so if there is some pattern correlating to specific times and/or or particular network/system events. And then probably contact the TO support (portal/email) with the logs/findings and/or open an issue at their https://gitlab.labs.nic.cz/turris

Allright, i will observe it, lets see if it occures again :slight_smile:
Thanks for help!

Hi,
I have the same problem. It seems that it always happens during Mac TimeMachine backup. I am using Turris as TimeCapsule according to this manual: https://doc.turris.cz/doc/en/public/create_time_capsule_for_osx_time_machine

It was working without problems but recently I have observed it. It appears when TimeMachine starts backup. It seems to be 100% reproducible. Omnia runs on 3.11.3

Mhh, i do not have a MacBook (so no TimeMachine). But this would explain the rare occurce for my setup.

I’m keep getting same warning on my Omnia. No TimeMachine, no USB devices connected.

I haven’t seen it again since posting above :confused:

I still have the same problem after latest update :frowning: