Comment 14 for bug 1777194

------- Comment From <email address hidden> 2018-07-20 01:38 EDT-------
(In reply to comment #42)
> I built a .deb version of the kernel that is currently in -proposed.
> The test kernel can be downloaded from:
> http://kernel.ubuntu.com/~jsalisbury/lp1777194
>
> Can you test this kernel and see if it resolves this bug?

I am seeing the following LOCKUP on the above kernel.

# uname -a
Linux lep8d 4.15.0-29-generic #32~lp1777194 SMP Thu Jul 19 16:21:31 UTC 2018 ppc64le ppc64le ppc64le GNU/Linux

[ 349.854120] Watchdog CPU:16 Hard LOCKUP
[ 349.854129] Modules linked in: userio(E) serpent_generic(E) hci_vhci(E) bluetooth(E) ecdh_generic(E) twofish_generic(E) twofish_common(E) cuse(E) vhost_vsock(E) vmw_vsock_virtio_transport_common(E) vsock(E) lrw(E) uhid(E) hid(E) algif_skcipher(E) tgr192(E) wp512(E) rmd320(E) snd_seq(E) snd_seq_device(E) unix_diag(E) snd_timer(E) sctp(E) rmd256(E) snd(E) soundcore(E) rmd160(E) rmd128(E) md4(E) vhost_net(E) vhost(E) tap(E) algif_hash(E) dccp_ipv4(E) dccp(E) af_alg(E) xt_CHECKSUM(E) iptable_mangle(E) ipt_MASQUERADE(E) nf_nat_masquerade_ipv4(E) iptable_nat(E) nf_nat_ipv4(E) nf_nat(E) nf_conntrack_ipv4(E) nf_defrag_ipv4(E) xt_conntrack(E) nf_conntrack(E) libcrc32c(E) ipt_REJECT(E) nf_reject_ipv4(E) xt_tcpudp(E) bridge(E) stp(E) llc(E) ebtable_filter(E) ebtables(E) devlink(E) ip6table_filter(E) ip6_tables(E)
[ 349.854595] iptable_filter(E) kvm_hv(E) kvm(E) binfmt_misc(E) dm_multipath(E) scsi_dh_rdac(E) scsi_dh_emc(E) scsi_dh_alua(E) uio_pdrv_genirq(E) uio(E) ipmi_powernv(E) ipmi_devintf(E) ipmi_msghandler(E) vmx_crypto(E) powernv_rng(E) powernv_op_panel(E) ibmpowernv(E) leds_powernv(E) crct10dif_vpmsum(E) nfsd(E) sch_fq_codel(E) auth_rpcgss(E) nfs_acl(E) lockd(E) grace(E) sunrpc(E) ip_tables(E) x_tables(E) autofs4(E) ses(E) enclosure(E) scsi_transport_sas(E) btrfs(E) xor(E) zstd_compress(E) raid6_pq(E) uas(E) usb_storage(E) crc32c_vpmsum(E) tg3(E) ipr(E)
[ 349.854940] CPU: 16 PID: 1634 Comm: ureadahead Tainted: G E 4.15.0-29-generic #32~lp1777194
[ 349.854949] NIP: c00000000029738c LR: c000000000297430 CTR: c0000000000aa8a0
[ 349.854961] REGS: c000000007ee3d80 TRAP: 0900 Tainted: G E (4.15.0-29-generic)
[ 349.854993] MSR: 9000000000009033 <SF,HV,EE,ME,IR,DR,RI,LE> CR: 28002848 XER: 00000000
[ 349.855081] CFAR: c00000000029742c SOFTE: 0
GPR00: c000000000297430 c000002ffff13cc0 c0000000016eaf00 c000000fff924360
GPR04: 0000000000000010 c000000fff924360 c00000000171dd78 000000000000b000
GPR08: c000000001721ee0 0000000000000003 0000000000000000 c000000ff9004928
GPR12: c0000000000aa8a0 c000000007a2b000 0000000000000000 0000000000000001
GPR16: 0000000000240000 00000e8aa6080160 0000000000000014 0000000000000000
GPR20: 0000000000000040 c000000fa02a0000 c000000fa02a01d0 0000000000000001
GPR24: 0000000000000002 0000000000000010 c000002ff3171800 c000002ffff13ef0
GPR28: fffffffffffffff8 0000000000000002 0000000000000003 c000000ffa110450
[ 349.855354] NIP [c00000000029738c] irq_work_run_list+0x8c/0x100
[ 349.855373] LR [c000000000297430] irq_work_run+0x30/0x60
[ 349.855384] Call Trace:
[ 349.855400] [c000002ffff13cc0] [c0000000002973b0] irq_work_run_list+0xb0/0x100 (unreliable)
[ 349.855415] [c000002ffff13d00] [c000000000297430] irq_work_run+0x30/0x60
[ 349.855432] [c000002ffff13d30] [c0000000001d7268] flush_smp_call_function_queue+0xd8/0x1d0
[ 349.855439] [c000002ffff13db0] [c00000000004923c] smp_ipi_demux_relaxed+0x9c/0x110
[ 349.855445] [c000002ffff13df0] [c000000000098be4] icp_native_ipi_action+0x64/0x80
[ 349.855468] [c000002ffff13e10] [c000000000192440] __handle_irq_event_percpu+0x90/0x300
[ 349.855487] [c000002ffff13ed0] [c0000000001926e8] handle_irq_event_percpu+0x38/0x90
[ 349.855510] [c000002ffff13f10] [c000000000198f74] handle_percpu_irq+0x84/0xd0
[ 349.855527] [c000002ffff13f40] [c000000000190b0c] generic_handle_irq+0x4c/0x70
[ 349.855549] [c000002ffff13f60] [c00000000001787c] __do_irq+0x7c/0x1c0
[ 349.855569] [c000002ffff13f90] [c00000000002a090] call_do_irq+0x14/0x24
[ 349.855575] [c000000004e4b7a0] [c000000000017a5c] do_IRQ+0x9c/0x130
[ 349.855582] [c000000004e4b7f0] [c000000000008c24] hardware_interrupt_common+0x114/0x120
[ 349.855588] --- interrupt: 501 at replay_interrupt_return+0x0/0x4
LR = arch_local_irq_restore+0x74/0x90
[ 349.855593] [c000000004e4bae0] [c000000fa0280000] 0xc000000fa0280000 (unreliable)
[ 349.855599] [c000000004e4bb00] [c00000000024b158] ring_buffer_empty_cpu+0xa8/0x150
[ 349.855612] [c000000004e4bb40] [c00000000024e560] __find_next_entry+0xe0/0x260
[ 349.855617] [c000000004e4bbe0] [c000000000257704] trace_find_next_entry_inc+0x34/0xd0
[ 349.855622] [c000000004e4bc10] [c000000000257818] s_next+0x78/0x100
[ 349.855626] [c000000004e4bc50] [c0000000002582c0] s_start+0x180/0x350
[ 349.855643] [c000000004e4bcd0] [c00000000040ef1c] seq_read+0xfc/0x610
[ 349.855654] [c000000004e4bd70] [c0000000003d509c] __vfs_read+0x3c/0x70
[ 349.855657] [c000000004e4bd90] [c0000000003d518c] vfs_read+0xbc/0x1b0
[ 349.855661] [c000000004e4bde0] [c0000000003d5788] SyS_read+0x68/0x110
[ 349.855672] [c000000004e4be30] [c00000000000b284] system_call+0x58/0x6c
[ 349.855689] Instruction dump:
[ 349.855700] fbc10030 f8010050 60000000 60000000 60420000 eb9f0008 ebdf0000 3b9cfff8
[ 349.855786] 7bdd07a4 7c0004ac 7d20f8a8 7fa0f9ad <40c2fff8> 7c0004ac e93f0010 7fe3fb78
[ 355.660066] Watchdog CPU:16 became unstuck

However, I am retrying again for the initial reported bug trace.