Bug 103709

https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_3336/shard-apl3/igt@drv_selftest@mock_sanitycheck.html

https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_3336/shard-apl3/dmesg-1510494904_Panic_3.log

<6>[ 1429.525560] perf: interrupt took too long (2501 > 2500), lowering kernel.perf_event_max_sample_rate to 79000
<12>[ 1554.489840] owatch: TIMEOUT!
<12>[ 1554.489919] owatch: timeout for /dev/watchdog0 set to 10 (requested 10)
<6>[ 1554.489990] sysrq: SysRq : Trigger a crash
<1>[ 1554.490010] BUG: unable to handle kernel NULL pointer dereference at           (null)
<1>[ 1554.490035] IP: sysrq_handle_crash+0x45/0x80
<6>[ 1554.490046] PGD 216f1b067 P4D 216f1b067 PUD 272dd1067 PMD 0 
<4>[ 1554.490065] Oops: 0002 [#2] PREEMPT SMP
<0>[ 1554.490078] Dumping ftrace buffer:
<0>[ 1554.490092]    (ftrace buffer empty)
<4>[ 1554.490101] Modules linked in: vgem snd_hda_codec_hdmi snd_hda_codec_realtek snd_hda_codec_generic i915 x86_pkg_temp_thermal coretemp crct10dif_pclmul crc32_pclmul snd_hda_intel snd_hda_codec ghash_clmulni_intel snd_hwdep snd_hda_core snd_pcm lpc_ich r8169 mei_me mii mei prime_numbers pinctrl_broxton pinctrl_intel
<4>[ 1554.490192] CPU: 3 PID: 8475 Comm: owatch Tainted: G     UD W       4.14.0-rc8-CI-CI_DRM_3336+ #1
<4>[ 1554.490210] Hardware name:                  /NUC6CAYB, BIOS AYAPLCEL.86A.0040.2017.0619.1722 06/19/2017
<4>[ 1554.490229] task: ffff88023b7ca780 task.stack: ffffc90000958000
<4>[ 1554.490243] RIP: 0010:sysrq_handle_crash+0x45/0x80
<4>[ 1554.490254] RSP: 0018:ffffc9000095bde0 EFLAGS: 00010282
<4>[ 1554.490267] RAX: ffff88023b7ca780 RBX: 0000000000000063 RCX: 0000000000000001
<4>[ 1554.490281] RDX: ffffffff8159d19b RSI: 0000000000000001 RDI: ffffffff81e4d600
<4>[ 1554.490296] RBP: ffffc9000095bde0 R08: 0000000000000001 R09: 0000000000000000
<4>[ 1554.490310] R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
<4>[ 1554.490324] R13: 000000000000000f R14: ffffffff81ebefc0 R15: ffffc9000095bf20
<4>[ 1554.490340] FS:  00007fbdc11e9700(0000) GS:ffff88027fd80000(0000) knlGS:0000000000000000
<4>[ 1554.490356] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
<4>[ 1554.490369] CR2: 0000000000000000 CR3: 000000023f731000 CR4: 00000000003406e0
<4>[ 1554.490383] Call Trace:
<4>[ 1554.490392]  __handle_sysrq+0x132/0x210
<4>[ 1554.490404]  write_sysrq_trigger+0x51/0x60
<4>[ 1554.490416]  proc_reg_write+0x42/0x70
<4>[ 1554.490427]  __vfs_write+0x28/0x130
<4>[ 1554.490438]  ? rcu_sync_lockdep_assert+0x12/0x60
<4>[ 1554.490450]  ? __sb_start_write+0x10c/0x200
<4>[ 1554.490461]  vfs_write+0xc8/0x1c0
<4>[ 1554.490472]  SyS_write+0x49/0xb0
<4>[ 1554.490483]  entry_SYSCALL_64_fastpath+0x1c/0xb1
<4>[ 1554.490495] RIP: 0033:0x7fbdc0d158f0
<4>[ 1554.490504] RSP: 002b:00007ffc33774728 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
<4>[ 1554.490521] RAX: ffffffffffffffda RBX: 00000000015b0020 RCX: 00007fbdc0d158f0
<4>[ 1554.490535] RDX: 0000000000000001 RSI: 00000000015b0250 RDI: 0000000000000003
<4>[ 1554.490550] RBP: 00007fbdc0fdb400 R08: 00007fbdc11e9700 R09: 0000000000000410
<4>[ 1554.490564] R10: 00007fbdc0fdeb58 R11: 0000000000000246 R12: 0000000000000000
<4>[ 1554.490579] R13: 00007ffc33774970 R14: 0000000000000000 R15: 0000000000000000
<4>[ 1554.490597] Code: 34 e8 80 ea b5 ff 48 c7 c2 9b d1 59 81 be 01 00 00 00 48 c7 c7 00 d6 e4 81 e8 a8 05 b4 ff c7 05 4e 0c b7 00 01 00 00 00 0f ae f8 <c6> 04 25 00 00 00 00 01 5d c3 e8 0c 19 b6 ff 84 c0 75 c3 48 c7 
<1>[ 1554.490719] RIP: sysrq_handle_crash+0x45/0x80 RSP: ffffc9000095bde0
<4>[ 1554.490731] CR2: 0000000000000000
<4>[ 1554.490742] ---[ end trace f0164b3c7089a8f5 ]---
<0>[ 1554.512892] Kernel panic - not syncing: Fatal exception
<0>[ 1554.512922] Dumping ftrace buffer:
<0>[ 1554.512934]    (ftrace buffer empty)
<0>[ 1554.512944] Kernel Offset: disabled