[selftest/powerpc] mainline kernel panics with tm/tm-signal-context-chk-vsx.c tests

Hi,

Today's mainline kernel panics and machine rebooted when running kernel
selftest on powerpc.

Test:  tm/tm-signal-context-chk-vsx.c
kernel version : 4.12.0-rc7
Machine : Power 8 Bare-metal
config: attached, config_4k_pages
gcc: 4.8.5

kernel traces:
--------------
tm-signal-msr-r[39659]: bad frame in rt_sigreturn: 00003ffff40562a0 nip
00003fff934e9b18 lr 00003fff936b04d8
tm-signal-stack[39667]: bad frame in setup_rt_frame: 0000000000000000
nip 0000000010000cc4 lr 0000000010000ca8
------------[ cut here ]------------
Kernel BUG at c0000000015cbefc [verbose debug info unavailable]
Unexpected TM Bad Thing exception at c0000000015cbefc (msr 0x2a03031)
Oops: Unrecoverable exception, sig: 6 [#1]
SMP NR_CPUS=2048
NUMA
PowerNV
Dumping ftrace buffer:
   (ftrace buffer empty)
Modules linked in: rcutorture bridge iptable_mangle torture
ipt_MASQUERADE nf_nat_masquerade_ipv4 iptable_nat nf_nat_ipv4 nf_nat
nf_conntrack_ipv4 nf_defrag_ipv4 xt_conntrack nf_conntrack ipt_REJECT
nf_reject_ipv4 xt_tcpudp tun stp llc kvm_hv kvm iptable_filter
vmx_crypto powernv_rng powernv_op_panel rng_core leds_powernv led_class
binfmt_misc nfsd ip_tables x_tables autofs4 [last unloaded: rcutorture]
CPU: 0 PID: 41291 Comm: tm-signal-conte Not tainted 4.12.0-rc7-autotest #1
task: c0000007d4448000 task.stack: c0000007d8370000
NIP: c0000000015cbefc LR: c0000000015e97f0 CTR: 0000000000000000
REGS: c0000007d83739a0 TRAP: 0700   Not tainted  (4.12.0-rc7-autotest)
MSR: 9000000302a03031 <SF,HV,VEC,VSX,FP,ME,IR,DR,LE,TM[SE]>
  CR: 44000848  XER: 20000000
CFAR: c0000000015cbeac SOFTE: 1
PACATMSCRATCH: 900000010280b033
GPR00: c0000000015e97d8 c0000007d8373c20 c00000000268f000 00003fffdf088ec8
GPR04: 00003fffdf089150 00003fffdf088150 0000000000000000 c0000007d444a050
GPR08: 0000000200000000 0000000000000000 0000000000000000 000c000000000000
GPR12: c0000007d4449a10 c00000000fdc0000 0000000000000000 0000000000000000
GPR16: 0000000000000000 0000000000000000 0000000000000000 0000000000000000
GPR20: 0000000000000000 0000000000000000 0000000000000000 0000000000000000
GPR24: 0000000000000000 c0000007d44487a8 0000000000000000 00003fffdf088eb8
GPR28: c0000007d8373ea0 c0000007d8373d30 c0000007d4448000 00003fffdf088150
NIP [c0000000015cbefc] fast_exception_return+0xac/0xb4
LR [c0000000015e97f0] handle_rt_signal64+0xa0/0x790
Call Trace:
[c0000007d8373c20] [c0000000015e97d8] handle_rt_signal64+0x88/0x790 (unreliable)
[c0000007d8373d10] [c0000000015dbf60] do_signal+0x160/0x2d0
[c0000007d8373e00] [c0000000015dc254] do_notify_resume+0xc4/0xf0
[c0000007d8373e30] [c0000000015cbdc4] ret_from_except_lite+0x70/0x74
Instruction dump:
f84d02f8 e9a100d8 7c7b03a6 e84101a0 7c4ff120 e8410170 7c5a03a6 e8010070
e8410080 e8610088 e8810090 e8210078 <4c000024> 48000000 e8610178 88ed01db
---[ end trace a62498af9ec43680 ]---

Kernel panic - not syncing: Fatal exception
Dumping ftrace buffer:
   (ftrace buffer empty)
Rebooting in 10 seconds..


-- 
Regard's

Abdul Haleem
IBM Linux Technology Centre