Re: [next-20170124] Kernel oops(rt6_fill_node) during reboot of LPAR

[David Ahern]

On 1/27/17 5:54 AM, Sachin Sant wrote:
> While rebooting PowerVM LPAR running 4.10.0-rc5-next-20170124
> on a POWER8 box, following kernel oops is displayed.
> 
> This problem was introduced with next-20170123. next-20170120 works.
> Initial analysis points to following patch included with next-20170123
> 
> commit a1a22c12060e4b9c52f45d4b3460f614e00162a2
> net: ipv6: Keep nexthop of multipath route on admin down

Thanks for the report. Fixed by:

https://git.kernel.org/cgit/linux/kernel/git/davem/net-next.git/commit/?id=1f17e2f2c8a8be3430813119fa7b633398f6185b

[next-20170124] Kernel oops(rt6_fill_node) during reboot of LPAR

[Sachin Sant]

While rebooting PowerVM LPAR running 4.10.0-rc5-next-20170124
on a POWER8 box, following kernel oops is displayed.

This problem was introduced with next-20170123. next-20170120 works.
Initial analysis points to following patch included with next-20170123

commit a1a22c12060e4b9c52f45d4b3460f614e00162a2
net: ipv6: Keep nexthop of multipath route on admin down


[  OK  ] Stopped Logout off all iSCSI sessions on shutdown.
[  OK  ] Stopped CUPS Printing Service.
[  OK  ] Stopped Dynamic System Tuning Daemon.
[  OK  ] Stopped target Network.
 Stopping LSB: Bring up/down networking...
[   86.292027] Unable to handle kernel paging request for data at address 
0x01d4
[   86.292050] Faulting instruction address: 0xc08734b0
[   86.292054] Oops: Kernel access of bad area, sig: 11 [#1]
[   86.292056] SMP NR_CPUS=2048 
[   86.292057] NUMA 
[   86.292059] pSeries
[   86.292062] Modules linked in: xt_CHECKSUM ipt_MASQUERADE 
nf_nat_masquerade_ipv4 tun kvm_pr kvm ip6t_rpfilter ipt_REJECT nf_reject_ipv4 
ip6t_REJECT nf_reject_ipv6 xt_conntrack ip_set nfnetlink ebtable_nat 
ebtable_broute bridge stp llc ip6table_nat nf_conntrack_ipv6 nf_defrag_ipv6 
nf_nat_ipv6 ip6table_mangle ip6table_security ip6table_raw iptable_nat 
nf_conntrack_ipv4 nf_defrag_ipv4 nf_nat_ipv4 nf_nat nf_conntrack iptable_mangle 
iptable_security iptable_raw ebtable_filter ebtables ip6table_filter ip6_tables 
iptable_filter rpcrdma ib_isert iscsi_target_mod ib_iser libiscsi 
scsi_transport_iscsi ib_srpt target_core_mod ib_srp ib_ipoib rdma_ucm ib_ucm 
ib_uverbs ib_umad rdma_cm ib_cm iw_cm iw_cxgb3 ib_core ghash_generic xts 
gf128mul tpm_ibmvtpm tpm vmx_crypto sg pseries_rng nfsd auth_rpcgss nfs_acl 
lockd
[   86.292099]  grace sunrpc ip_tables xfs libcrc32c sr_mod sd_mod cdrom cxgb3 
ibmvscsi ibmveth scsi_transport_srp mdio dm_mirror dm_region_hash dm_log dm_mod
[   86.292109] CPU: 0 PID: 1500 Comm: NetworkManager Not tainted 
4.10.0-rc5-next-20170124 #1
[   86.292113] task: c319b800 task.stack: c000fb9e
[   86.292115] NIP: c08734b0 LR: c0873444 CTR: c0879490
[   86.292118] REGS: c000fb9e33d0 TRAP: 0300   Not tainted  
(4.10.0-rc5-next-20170124)
[   86.292121] MSR: 80009033 
[   86.292124]   CR: 28004428  XER: 
[   86.292128] CFAR: c0008850 DAR: 01d4 DSISR: 4000 
SOFTE: 1 
[   86.292128] GPR00: c0873444 c000fb9e3650 c0ff9f00 
 
[   86.292128] GPR04: c000fb9e36b4 0004 c0026ff50024 
7e80 
[   86.292128] GPR08:   0002 
0014 
[   86.292128] GPR12: c0879490 ce80  
 
[   86.292128] GPR16:    
c0fa6d00 
[   86.292128] GPR20:  c0fa6d00  
c0026a5bba00 
[   86.292128] GPR24: c0fa6d00   
384005dc 
[   86.292128] GPR28:  c0026a5bba00 c00279f71c00 
c0026ff5 
[   86.292163] NIP [c08734b0] rt6_fill_node.isra.42+0x150/0x640
[   86.292166] LR [c0873444] rt6_fill_node.isra.42+0xe4/0x640
[   86.292169] Call Trace:
[   86.292171] [c000fb9e3650] [c0873444] 
rt6_fill_node.isra.42+0xe4/0x640 (unreliable)
[   86.292175] [c000fb9e3710] [c0878718] rt6_dump_route+0x68/0xa0
[   86.292178] [c000fb9e3780] [c08794d8] fib6_dump_node+0x48/0xb0
[   86.292182] [c000fb9e37b0] [c0878de8] 
fib6_walk_continue+0x1d8/0x200
[   86.292185] [c000fb9e3800] [c0879134] fib6_walk+0x44/0xa0
[   86.292189] [c000fb9e3840] [c087a0f4] inet6_dump_fib+0x1f4/0x2d0
[   86.292193] [c000fb9e38f0] [c07ae9cc] netlink_dump+0x14c/0x370
[   86.292196] [c000fb9e3940] [c07af428] 
__netlink_dump_start+0x198/0x210
[   86.292201] [c000fb9e3990] [c07833f4] 
rtnetlink_rcv_msg+0x194/0x300
[   86.292204] [c000fb9e3a10] [c07b1e48] netlink_rcv_skb+0x128/0x140
[   86.292208] [c000fb9e3a50] [c077f46c] rtnetlink_rcv+0x3c/0x60
[   86.292211] [c000fb9e3a80] [c07b13dc] netlink_unicast+0x1ec/0x370
[   86.292215] [c000fb9e3ae0] [c07b1adc] netlink_sendmsg+0x40c/0x480
[   86.292219] [c000fb9e3b70] [c073caec] sock_sendmsg+0x5c/0x90
[   86.292223] [c000fb9e3ba0] [c073d79c] ___sys_sendmsg+0x31c/0x330
[   86.292226] [c000fb9e3d30] [c073ece4] __sys_sendmsg+0x54/0xc0
[   86.292229] [c000fb9e3dd0] [c073f88c] SyS_socketcall+0x35c/0x3e0
[   86.292234] [c000fb9e3e30] [c000b184] system_call+0x38/0xe0
[   86.292236] Instruction dump:
[   86.292238] 3920 913f0018 e93e0018 e9490048 794807e1 41820010 e9290048 
792af7e3 
[   86.292243] 41820024 39200010 913f0018 e93e0158 <812901d4> 2f89 419e000c 
39200011 
[   86.292249] ---[ end trace