Issue

• BUG: unable to handle kernel NULL pointer dereference at 0000000000000008

[356265.495587] BUG: unable to handle kernel NULL pointer dereference at 0000000000000008
[356265.495747] IP: [<ffffffff8111588c>] perf_event_update_userpage+0x4c/0x110
[356265.495840] PGD 3fc3d79067 PUD 3f2f1ec067 PMD 0 
[356265.495929] Oops: 0002 [#1] SMP 
[356265.496011] last sysfs file: /sys/devices/system/cpu/online
[356265.497437] CPU 8 
[356265.497445] Modules linked in: mlx4_core ipmi_watchdog ipmi_devintf nfs lockd fscache auth_rpcgss nfs_acl sunrpc mptctl mptbase autofs4 bonding 8021q garp stp llc ipv6 ext3 jbd iTCO_wdt iTCO_vendor_support raid0 microcode power_meter iomemory_vsl(P)(U) hpilo hpwdt serio_raw sg tg3 ptp pps_core be2net lpc_ich mfd_core ioatdma dca shpchp ext4 jbd2 mbcache sd_mod crc_t10dif pata_acpi ata_generic ata_piix hpsa dm_mirror dm_region_hash dm_log dm_mod [last unloaded: mlx4_en]
[356265.498181] 
[356265.498251] Pid: 26541, comm: python Tainted: P        W  ---------------    2.6.32-431.20.3.el6.x86_64 #1 HP ProLiant DL380p Gen8
[356265.498405] RIP: 0010:[<ffffffff8111588c>]  [<ffffffff8111588c>] perf_event_update_userpage+0x4c/0x110
[356265.498551] RSP: 0018:ffff883f321bfaa0  EFLAGS: 00010086
[356265.498626] RAX: ffff887f971d0248 RBX: ffff887f971d0000 RCX: 00014405864f23fb
[356265.498763] RDX: 00014405864f23fb RSI: ffff884121400000 RDI: 0000000000000082
[356265.498902] RBP: ffff883f321bfae0 R08: 0000000000000000 R09: 0000000000000000
[356265.499039] R10: 0000000000000000 R11: 0000000000000003 R12: 0000000000000000
[356265.499177] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
[356265.499320] FS:  00007fd0295b5700(0000) GS:ffff884121400000(0000) knlGS:0000000000000000
[356265.499468] CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
[356265.499544] CR2: 0000000000000008 CR3: 0000003f45cc7000 CR4: 00000000000407e0
[356265.499689] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[356265.499834] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
[356265.499976] Process python (pid: 26541, threadinfo ffff883f321be000, task ffff883f78f62aa0)
[356265.500123] Stack:
[356265.500195]  ffff883f852ae420 ffff883fe4acf3c0 ffff884121419438 ffff887f971d0000
[356265.500291] <d> fffffffffffffffe 0000000000000001 00000000fffffffe 0000000000000002
[356265.500452] <d> ffff883f321bfb10 ffffffff8101d93d ffff887f971d0000 0000000000000000
[356265.500680] Call Trace:
[356265.500758]  [<ffffffff8101d93d>] x86_perf_event_set_period+0xdd/0x170
[356265.500837]  [<ffffffff8101da26>] x86_pmu_start+0x56/0x100
[356265.500914]  [<ffffffff8101dcfa>] x86_pmu_enable+0x22a/0x280
[356265.500993]  [<ffffffff811140eb>] perf_pmu_enable+0x2b/0x40
[356265.501071]  [<ffffffff8111765e>] perf_event_context_sched_in+0x7e/0xc0
[356265.501151]  [<ffffffff81117b85>] __perf_event_task_sched_in+0x85/0x90
[356265.501231]  [<ffffffff8105db20>] finish_task_switch+0xb0/0xf0
[356265.501311]  [<ffffffff8152883e>] thread_return+0x4e/0x760
[356265.501389]  [<ffffffff81059096>] ? enqueue_task+0x66/0x80
[356265.501468]  [<ffffffff8105559d>] ? check_preempt_curr+0x6d/0x90
[356265.501546]  [<ffffffff8152aea5>] rwsem_down_failed_common+0x95/0x1d0
[356265.501626]  [<ffffffff8152b036>] rwsem_down_read_failed+0x26/0x30
[356265.501705]  [<ffffffff8128f1e4>] call_rwsem_down_read_failed+0x14/0x30
[356265.501786]  [<ffffffff8152a534>] ? down_read+0x24/0x30
[356265.501865]  [<ffffffff8104a92e>] __do_page_fault+0x18e/0x480
[356265.501944]  [<ffffffff81064de3>] ? wake_up_new_task+0xd3/0x120
[356265.502024]  [<ffffffff81070bbd>] ? do_fork+0x13d/0x480
[356265.502102]  [<ffffffff8128f238>] ? call_rwsem_wake+0x18/0x30
[356265.502181]  [<ffffffff8152e37e>] do_page_fault+0x3e/0xa0
[356265.502262]  [<ffffffff8152b735>] page_fault+0x25/0x30
[356265.502338] Code: ca f8 ff 48 89 c2 48 8b 83 48 02 00 00 4c 8b ab 98 00 00 00 4c 8b b3 80 00 00 00 4c 8b bb 88 00 00 00 48 85 c0 74 5c 4c 8b 60 70 <41> 83 44 24 08 01 f6 83 58 01 00 00 01 74 65 41 c7 44 24 0c 00 
[356265.502821] RIP  [<ffffffff8111588c>] perf_event_update_userpage+0x4c/0x110
[356265.502905]  RSP <ffff883f321bfaa0>
[356265.502979] CR2: 0000000000000008