Subject: [powerpc/powervm]kernel BUG at mm/memory_hotplug.c:1864!

From: vrbagal1 <[email-masked]>
Date: Fri, 08 Jun 2018 16:44:24 +0530

Greetings!!!

I am seeing kernel bug followed by oops message and system reboots, 
while running dlpar memory hotplug test.

Machine Details: Power6 PowerVM Platform
GCC version: (gcc version 4.8.3 20140911 (Red Hat 4.8.3-7) (GCC))
Test case: dlpar memory hotplug test 
(https://github.com/avocado-framework-tests/avocado-misc-tests/blob/master/memory/memhotplug.py)
Kernel Version: Linux version 4.17.0-autotest

I am seeing this bug on rc7 as well.

Attached is the .config file

Traces:

kernel BUG at mm/memory_hotplug.c:1864!
  Oops: Exception in kernel mode, sig: 5 [#1]
  BE SMP NR_CPUS=1024 NUMA pSeries
  Dumping ftrace buffer:
     (ftrace buffer empty)
  Modules linked in: rpadlpar_io(E) rpaphp(E) nf_conntrack_netbios_ns(E) 
nf_conntrack_broadcast(E) ip6t_REJECT(E) nf_reject_ipv6(E) 
nf_conntrack_ipv6(E) nf_defrag_ipv6(E) cfg80211(E) rfkill(E) 
ipt_REJECT(E) nf_reject_ipv4(E) nf_conntrack_ipv4(E) nf_defrag_ipv4(E) 
xt_conntrack(E) nf_conntrack(E) libcrc32c(E) ebtable_nat(E) 
ebtable_broute(E) bridge(E) stp(E) llc(E) ebtable_filter(E) ebtables(E) 
ip6table_mangle(E) ip6table_security(E) ip6table_raw(E) 
ip6table_filter(E) ip6_tables(E) iptable_mangle(E) iptable_security(E) 
iptable_raw(E) iptable_filter(E) ip_tables(E) ses(E) osst(E) 
enclosure(E) scsi_transport_sas(E) st(E) nfsd(E) auth_rpcgss(E) 
nfs_acl(E) lockd(E) uio_pdrv_genirq(E) uio(E) ehea(E) sunrpc(E) grace(E) 
ipv6(E) crc_ccitt(E) autofs4(E) ext4(E) mbcache(E) jbd2(E) sd_mod(E) 
sr_mod(E)
   cdrom(E) dm_mirror(E) dm_region_hash(E) dm_log(E) dm_mod(E) dax(E)
  CPU: 15 PID: 7585 Comm: drmgr Tainted: G            E     
4.17.0-autotest #1
  NIP:  c0000000002c97f4 LR: c0000000002c97f4 CTR: 0000000000000000
  REGS: c0000002acbfb3e0 TRAP: 0700   Tainted: G            E      
(4.17.0-autotest)
  MSR:  8000000000029032 <SF,EE,ME,IR,DR,RI>  CR: 24002442  XER: 20000000
  CFAR: c0000000002c682c IRQMASK: 0
  GPR00: c0000000002c97f4 c0000002acbfb660 c000000001129300 
ffffffffffffffea
  GPR04: c0000002b3dcdbd0 c0000002b3de4860 c0000000011e9300 
c0000000011e9300
  GPR08: c000000000cb9300 c0000002b3dd4678 00000002b3120000 
0000000000000033
  GPR12: 0000000024002444 c00000000eea0c00 0000000000000000 
0000000000000000
  GPR16: 0000000000000000 0000000000000000 0000000000000000 
0000000000000000
  GPR20: 0000000000000000 0000000000000000 0000000000000000 
0000000000000000
  GPR24: 0000000000000000 c0000002ad5aa010 0000000000000000 
0000000004000000
  GPR28: 0000000000000003 0000000000000003 0000000001000000 
0000000228000000
  NIP [c0000000002c97f4] .remove_memory+0x34/0x100
  LR [c0000000002c97f4] .remove_memory+0x34/0x100
  Call Trace:
  [c0000002acbfb660] [c0000000002c97f4] .remove_memory+0x34/0x100 
(unreliable)
  [c0000002acbfb6f0] [c0000000000baeb4] 
.pseries_remove_memblock+0xd4/0x130
  [c0000002acbfb790] [c0000000000bb178] 
.pseries_memory_notifier+0x268/0x280
  [c0000002acbfb820] [c00000000011464c] .notifier_call_chain+0x7c/0xf0
  [c0000002acbfb8c0] [c000000000114ab8] 
.__blocking_notifier_call_chain+0x58/0x90
  [c0000002acbfb960] [c000000000733e00] .of_property_notify+0x90/0xd0
  [c0000002acbfba10] [c00000000072ed84] .of_update_property+0x104/0x150
  [c0000002acbfbac0] [c0000000000ae2cc] .ofdt_write+0x3bc/0x6f0
  [c0000002acbfbb90] [c000000000369ae8] .proc_reg_write+0x78/0xc0
  [c0000002acbfbc10] [c0000000002d5b6c] .__vfs_write+0x3c/0x1e0
  [c0000002acbfbcf0] [c0000000002d5f50] .vfs_write+0xc0/0x230
  [c0000002acbfbd90] [c0000000002d62b4] .ksys_write+0x54/0x100
  [c0000002acbfbe30] [c00000000000b9dc] system_call+0x5c/0x70
  Instruction dump:
  fb81ffe0 fba1ffe8 fbc1fff0 fbe1fff8 7c9f2378 7c7c1b78 7ca42b78 7fe3fb78
  7cbe2b78 f8010010 f821ff71 4bffcff1 <0b030000> 4be1eff9 60000000 
3fa2fff5
  ---[ end trace b960873bb81597b4 ]---

Regards,
Venkat.