pkg/report: ignore down functions for task hung bugs

2 files changed, 446 insertions, 0 deletions

diff --git a/pkg/report/testdata/linux/report/254 b/pkg/report/testdata/linux/report/254
new file mode 100644
index 000000000..7dcf2902c
--- /dev/null
+++ b/pkg/report/testdata/linux/report/254
@@ -0,0 +1,281 @@
+TITLE: INFO: task hung in console_device
+
+[  962.377725] INFO: task init:2293 blocked for more than 120 seconds.
+[  962.377730]       Not tainted 4.4.132+ #53
+[  962.377731] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
+[  962.377743] init            D ffff88008ad8f5b0     0  2293      1 0x00000000
+[  962.377753]  ffff88008ad8f5b0 ffff8800b5584ee8 ffff8800b5584ef8 1ffff100115b1eaa
+[  962.377760]  0000000041b58a00 ffff8801db71f3f8 ffff8801db71f420 ffff8801db71ead8
+[  962.377768]  ffff8801db71eac0 ffff88008add0000 ffff8800b5584740 0000000000000000
+[  962.377769] Call Trace:
+[  962.377783]  [<ffffffff82a9df9c>] schedule+0x7c/0x1b0
+[  962.377790]  [<ffffffff82aae624>] schedule_timeout+0x3d4/0x690
+[  962.377796]  [<ffffffff82aae250>] ? usleep_range+0x130/0x130
+[  962.377806]  [<ffffffff8120ac09>] ? mark_held_locks+0xc9/0x160
+[  962.377813]  [<ffffffff82ab06ec>] ? _raw_spin_unlock_irq+0x2c/0x40
+[  962.377820]  [<ffffffff8120b02b>] ? trace_hardirqs_on_caller+0x38b/0x590
+[  962.377825]  [<ffffffff82aab9b0>] __down+0x130/0x250
+[  962.377832]  [<ffffffff82aab880>] ? __ww_mutex_lock_interruptible+0x2780/0x2780
+[  962.377839]  [<ffffffff81201a13>] down+0x63/0x80
+[  962.377845]  [<ffffffff81226da1>] console_lock+0x31/0x80
+[  962.377853]  [<ffffffff81501021>] ? kmem_cache_alloc_trace+0x141/0x340
+[  962.377860]  [<ffffffff8122c341>] console_device+0x21/0xc0
+[  962.377867]  [<ffffffff81ecd220>] tty_open+0x8b0/0xee0
+[  962.377873]  [<ffffffff81ecc970>] ? tty_init_dev+0x430/0x430
+[  962.377882]  [<ffffffff81555f55>] ? chrdev_open+0xc5/0x570
+[  962.377888]  [<ffffffff81ecc970>] ? tty_init_dev+0x430/0x430
+[  962.377895]  [<ffffffff815560be>] chrdev_open+0x22e/0x570
+[  962.377901]  [<ffffffff81555e90>] ? cdev_put.part.1+0x50/0x50
+[  962.377909]  [<ffffffff81b93994>] ? security_file_open+0x94/0x190
+[  962.377916]  [<ffffffff8154429d>] do_dentry_open+0x67d/0xc60
+[  962.377922]  [<ffffffff81555e90>] ? cdev_put.part.1+0x50/0x50
+[  962.377928]  [<ffffffff81547a4f>] vfs_open+0x12f/0x220
+[  962.377935]  [<ffffffff8156a988>] ? may_open.isra.37+0x158/0x240
+[  962.377941]  [<ffffffff81578de4>] path_openat+0x504/0x3930
+[  962.377949]  [<ffffffff81245fd7>] ? debug_lockdep_rcu_enabled+0x77/0x90
+[  962.377957]  [<ffffffff815788e0>] ? path_lookupat.isra.33+0x420/0x420
+[  962.377963]  [<ffffffff81205c62>] ? __lock_is_held+0xa2/0xf0
+[  962.377968]  [<ffffffff814ffa0c>] ? deactivate_slab+0x45c/0x480
+[  962.377976]  [<ffffffff81205c62>] ? __lock_is_held+0xa2/0xf0
+[  962.377983]  [<ffffffff8157f1c0>] do_filp_open+0x190/0x250
+[  962.377990]  [<ffffffff8157f030>] ? user_path_mountpoint_at+0x80/0x80
+[  962.377997]  [<ffffffff82ab0667>] ? _raw_spin_unlock+0x27/0x40
+[  962.378004]  [<ffffffff815a79f8>] ? __alloc_fd+0x1f8/0x4a0
+[  962.378010]  [<ffffffff8154839a>] do_sys_open+0x30a/0x930
+[  962.378016]  [<ffffffff81548090>] ? filp_open+0x70/0x70
+[  962.378022]  [<ffffffff81ec768e>] ? proc_clear_tty+0xde/0x150
+[  962.378028]  [<ffffffff82ab0c0c>] ? _raw_write_unlock_irq+0x2c/0x40
+[  962.378035]  [<ffffffff815489f2>] SyS_open+0x32/0x40
+[  962.378042]  [<ffffffff82ab1121>] entry_SYSCALL_64_fastpath+0x1e/0x9a
+[  962.378047] 1 lock held by init/2293:
+[  962.378060]  #0:  (tty_mutex){+.+.+.}, at: [<ffffffff81eccea1>] tty_open+0x531/0xee0
+[  962.378068]   task                        PC stack   pid father
+[  962.378098] init            D ffff88008ad8f5b0     0  2293      1 0x00000000
+[  962.378350]  ffff88008ad8f5b0 ffff8800b5584ee8 ffff8800b5584ef8 1ffff100115b1eaa
+[  962.378357]  0000000041b58a00 ffff8801db71f3f8 ffff8801db71f420 ffff8801db71ead8
+[  962.378364]  ffff8801db71eac0 ffff88008add0000 ffff8800b5584740 0000000000000000
+[  962.378366] Call Trace:
+[  962.378373]  [<ffffffff82a9df9c>] schedule+0x7c/0x1b0
+[  962.378379]  [<ffffffff82aae624>] schedule_timeout+0x3d4/0x690
+[  962.378385]  [<ffffffff82aae250>] ? usleep_range+0x130/0x130
+[  962.378392]  [<ffffffff8120ac09>] ? mark_held_locks+0xc9/0x160
+[  962.378398]  [<ffffffff82ab06ec>] ? _raw_spin_unlock_irq+0x2c/0x40
+[  962.378405]  [<ffffffff8120b02b>] ? trace_hardirqs_on_caller+0x38b/0x590
+[  962.378410]  [<ffffffff82aab9b0>] __down+0x130/0x250
+[  962.378417]  [<ffffffff82aab880>] ? __ww_mutex_lock_interruptible+0x2780/0x2780
+[  962.378423]  [<ffffffff81201a13>] down+0x63/0x80
+[  962.378429]  [<ffffffff81226da1>] console_lock+0x31/0x80
+[  962.378435]  [<ffffffff81501021>] ? kmem_cache_alloc_trace+0x141/0x340
+[  962.378441]  [<ffffffff8122c341>] console_device+0x21/0xc0
+[  962.378447]  [<ffffffff81ecd220>] tty_open+0x8b0/0xee0
+[  962.378453]  [<ffffffff81ecc970>] ? tty_init_dev+0x430/0x430
+[  962.378460]  [<ffffffff81555f55>] ? chrdev_open+0xc5/0x570
+[  962.378466]  [<ffffffff81ecc970>] ? tty_init_dev+0x430/0x430
+[  962.378472]  [<ffffffff815560be>] chrdev_open+0x22e/0x570
+[  962.378479]  [<ffffffff81555e90>] ? cdev_put.part.1+0x50/0x50
+[  962.378485]  [<ffffffff81b93994>] ? security_file_open+0x94/0x190
+[  962.378491]  [<ffffffff8154429d>] do_dentry_open+0x67d/0xc60
+[  962.378497]  [<ffffffff81555e90>] ? cdev_put.part.1+0x50/0x50
+[  962.378503]  [<ffffffff81547a4f>] vfs_open+0x12f/0x220
+[  962.378509]  [<ffffffff8156a988>] ? may_open.isra.37+0x158/0x240
+[  962.378516]  [<ffffffff81578de4>] path_openat+0x504/0x3930
+[  962.378522]  [<ffffffff81245fd7>] ? debug_lockdep_rcu_enabled+0x77/0x90
+[  962.378529]  [<ffffffff815788e0>] ? path_lookupat.isra.33+0x420/0x420
+[  962.378535]  [<ffffffff81205c62>] ? __lock_is_held+0xa2/0xf0
+[  962.378545]  [<ffffffff814ffa0c>] ? deactivate_slab+0x45c/0x480
+[  962.378590]  [<ffffffff81205c62>] ? __lock_is_held+0xa2/0xf0
+[  962.378598]  [<ffffffff8157f1c0>] do_filp_open+0x190/0x250
+[  962.378604]  [<ffffffff8157f030>] ? user_path_mountpoint_at+0x80/0x80
+[  962.378611]  [<ffffffff82ab0667>] ? _raw_spin_unlock+0x27/0x40
+[  962.378617]  [<ffffffff815a79f8>] ? __alloc_fd+0x1f8/0x4a0
+[  962.378624]  [<ffffffff8154839a>] do_sys_open+0x30a/0x930
+[  962.378630]  [<ffffffff81548090>] ? filp_open+0x70/0x70
+[  962.378635]  [<ffffffff81ec768e>] ? proc_clear_tty+0xde/0x150
+[  962.378642]  [<ffffffff82ab0c0c>] ? _raw_write_unlock_irq+0x2c/0x40
+[  962.378648]  [<ffffffff815489f2>] SyS_open+0x32/0x40
+[  962.378655]  [<ffffffff82ab1121>] entry_SYSCALL_64_fastpath+0x1e/0x9a
+[  962.378665] init            D ffff88008adbf688     0  2294      1 0x00000000
+[  962.378691]  ffff88008adbf688 ffff8801d2aadf00 dffffc0000000000 0000000000000007
+[  962.378698]  ffffed003a555c00 ffff8801db71f3f8 ffff8801db71f420 ffff8801db71ead8
+[  962.378705]  ffff8801db71eac0 ffff8801d85a2f80 ffff8801d2aadf00 0000000000000000
+[  962.378706] Call Trace:
+[  962.378712]  [<ffffffff82a9df9c>] schedule+0x7c/0x1b0
+[  962.378718]  [<ffffffff82a9e7f5>] schedule_preempt_disabled+0x15/0x20
+[  962.378724]  [<ffffffff82aa4a18>] mutex_lock_nested+0x3a8/0x10d0
+[  962.378729]  [<ffffffff81eccea1>] ? tty_open+0x531/0xee0
+[  962.378735]  [<ffffffff815006bb>] ? ___slab_alloc+0x45b/0x580
+[  962.378741]  [<ffffffff81572200>] ? lookup_fast+0x950/0xe80
+[  962.378747]  [<ffffffff82aa4670>] ? mutex_lock_killable_nested+0x1240/0x1240
+[  962.378753]  [<ffffffff8150085f>] ? __slab_alloc+0x7f/0x90
+[  962.378758]  [<ffffffff81eccac5>] ? tty_open+0x155/0xee0
+[  962.378766]  [<ffffffff81505d95>] ? kasan_unpoison_shadow+0x35/0x50
+[  962.378773]  [<ffffffff81501021>] ? kmem_cache_alloc_trace+0x141/0x340
+[  962.378778]  [<ffffffff81eccac5>] ? tty_open+0x155/0xee0
+[  962.378783]  [<ffffffff81eccea1>] tty_open+0x531/0xee0
+[  962.378790]  [<ffffffff81ecc970>] ? tty_init_dev+0x430/0x430
+[  962.378796]  [<ffffffff81555f55>] ? chrdev_open+0xc5/0x570
+[  962.378802]  [<ffffffff81ecc970>] ? tty_init_dev+0x430/0x430
+[  962.378808]  [<ffffffff815560be>] chrdev_open+0x22e/0x570
+[  962.378815]  [<ffffffff81555e90>] ? cdev_put.part.1+0x50/0x50
+[  962.378821]  [<ffffffff81b93994>] ? security_file_open+0x94/0x190
+[  962.378827]  [<ffffffff8154429d>] do_dentry_open+0x67d/0xc60
+[  962.378833]  [<ffffffff81555e90>] ? cdev_put.part.1+0x50/0x50
+[  962.378839]  [<ffffffff81547a4f>] vfs_open+0x12f/0x220
+[  962.378845]  [<ffffffff8156a988>] ? may_open.isra.37+0x158/0x240
+[  962.378851]  [<ffffffff81578de4>] path_openat+0x504/0x3930
+[  962.378857]  [<ffffffff81245fd7>] ? debug_lockdep_rcu_enabled+0x77/0x90
+[  962.378865]  [<ffffffff815788e0>] ? path_lookupat.isra.33+0x420/0x420
+[  962.378871]  [<ffffffff81205c62>] ? __lock_is_held+0xa2/0xf0
+[  962.378877]  [<ffffffff814ffa0c>] ? deactivate_slab+0x45c/0x480
+[  962.378884]  [<ffffffff81205c62>] ? __lock_is_held+0xa2/0xf0
+[  962.378891]  [<ffffffff8157f1c0>] do_filp_open+0x190/0x250
+[  962.378898]  [<ffffffff8157f030>] ? user_path_mountpoint_at+0x80/0x80
+[  962.378905]  [<ffffffff82ab0667>] ? _raw_spin_unlock+0x27/0x40
+[  962.378911]  [<ffffffff815a79f8>] ? __alloc_fd+0x1f8/0x4a0
+[  962.378917]  [<ffffffff8154839a>] do_sys_open+0x30a/0x930
+[  962.378923]  [<ffffffff81548090>] ? filp_open+0x70/0x70
+[  962.378929]  [<ffffffff81ec768e>] ? proc_clear_tty+0xde/0x150
+[  962.378935]  [<ffffffff82ab0c0c>] ? _raw_write_unlock_irq+0x2c/0x40
+[  962.378942]  [<ffffffff815489f2>] SyS_open+0x32/0x40
+[  962.378948]  [<ffffffff82ab1121>] entry_SYSCALL_64_fastpath+0x1e/0x9a
+[  962.378958] init            D ffff88008addf688     0  2295      1 0x00000000
+[  962.378982]  ffff88008addf688 ffff88008add0000 dffffc0000000000 0000000000000007
+[  962.378990]  ffffed00115ba000 ffff8801db71f3f8 ffff8801db71f420 ffff8801db71ead8
+[  962.378997]  ffff8801db71eac0 ffff8801d9ce0000 ffff88008add0000 0000000000000000
+[  962.378998] Call Trace:
+[  962.379003] <Same stack as pid 2294>
+[  962.379009] init            D ffff88008adef688     0  2296      1 0x00000000
+[  962.379034]  ffff88008adef688 ffff88008add5f00 dffffc0000000000 0000000000000007
+[  962.379041]  ffffed00115bac00 ffff8801db71f3f8 ffff8801db71f420 ffff8801db71ead8
+[  962.379048]  ffff8801db71eac0 ffff8801d9ce0000 ffff88008add5f00 0000000000000000
+[  962.379049] Call Trace:
+[  962.379054] <Same stack as pid 2294>
+[  962.379061] init            D ffff88008ae2f688     0  2297      1 0x00000000
+[  962.379085]  ffff88008ae2f688 ffff88008add17c0 dffffc0000000000 0000000000000007
+[  962.379093]  ffffed00115ba300 ffff8801db71f3f8 ffff8801db71f420 ffff8801db71ead8
+[  962.379100]  ffff8801db71eac0 ffff88008add4740 ffff88008add17c0 0000000000000000
+[  962.379101] Call Trace:
+[  962.379105] <Same stack as pid 2294>
+[  962.379112] init            D ffff88008ae5f688     0  2298      1 0x00000000
+[  962.379136]  ffff88008ae5f688 ffff88008add4740 dffffc0000000000 0000000000000007
+[  962.379143]  ffffed00115ba900 ffff8801db71f3f8 ffff8801db71f420 ffff8801db71ead8
+[  962.379151]  ffff8801db71eac0 ffff8801d856df00 ffff88008add4740 0000000000000000
+[  962.379152] Call Trace:
+[  962.379157] <Same stack as pid 2294>
+[  962.379158] Sending NMI to all CPUs:
+[  962.380406] NMI backtrace for cpu 0
+[  962.380408] CPU: 0 PID: 2285 Comm: syz-executor491 Not tainted 4.4.132+ #53
+[  962.380412] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
+[  962.380415] task: ffff8801d85697c0 ti: ffff8800bade8000 task.ti: ffff8800bade8000
+[  962.380418] RIP: 0010:[<ffffffff81f014b0>]  [<ffffffff81f014b0>] io_serial_in+0x70/0x90
+[  962.380420] RSP: 0018:ffff8800badef7d8  EFLAGS: 00000002
+[  962.380423] RAX: dffffc0000000000 RBX: 00000000000003fd RCX: 0000000000000000
+[  962.380425] RDX: 00000000000003fd RSI: 0000000000000005 RDI: ffffffff846adad8
+[  962.380428] RBP: ffff8800badef7e8 R08: 0000000000000001 R09: 0000000000000000
+[  962.380431] R10: 0000000000000001 R11: ffffffff845377b5 R12: ffffffff846adaa0
+[  962.380434] R13: 0000000000000020 R14: fffffbfff08d5b97 R15: fffffbfff08d5b5d
+[  962.380437] FS:  0000000000a53880(0063) GS:ffff8801db600000(0000) knlGS:0000000000000000
+[  962.380439] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
+[  962.380442] CR2: 0000000020000180 CR3: 00000000b9f8c000 CR4: 0000000000160630
+[  962.380445] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
+[  962.380447] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
+[  962.380449] Stack:
+[  962.380452]  ffffffff846adaa0 000000000000270a ffff8800badef838 ffffffff81f02f74
+[  962.380455]  ffff8800badef8c0 ffffffff846adae8 ffffffff846adcba ffffffff846adaa0
+[  962.380457]  000000000000006f ffffffff81f030c0 dffffc0000000000 000000000000006f
+[  962.380459] Call Trace:
+[  962.380461]  [<ffffffff81f02f74>] wait_for_xmitr+0x94/0x1e0
+[  962.380464]  [<ffffffff81f030c0>] ? wait_for_xmitr+0x1e0/0x1e0
+[  962.380466]  [<ffffffff81f030e4>] serial8250_console_putchar+0x24/0x60
+[  962.380468]  [<ffffffff81eed98e>] uart_console_write+0x5e/0xf0
+[  962.380471]  [<ffffffff81f0d218>] serial8250_console_write+0x548/0x840
+[  962.380474]  [<ffffffff81f0ccd0>] ? exar_handle_irq+0x1c0/0x1c0
+[  962.380476]  [<ffffffff81d1efb7>] ? sprintf+0xa7/0xd0
+[  962.380478]  [<ffffffff81d1ef10>] ? scnprintf+0x100/0x100
+[  962.380481]  [<ffffffff81002297>] ? trace_hardirqs_on_thunk+0x17/0x19
+[  962.380483]  [<ffffffff81efc4a0>] ? univ8250_console_setup+0x100/0x100
+[  962.380486]  [<ffffffff81efc505>] univ8250_console_write+0x65/0x80
+[  962.380489]  [<ffffffff81228723>] call_console_drivers.constprop.30+0x1a3/0x360
+[  962.380491]  [<ffffffff8122b29c>] console_unlock+0x61c/0xa20
+[  962.380494]  [<ffffffff8122bbba>] vprintk_emit+0x51a/0x820
+[  962.380496]  [<ffffffff8122beed>] vprintk+0x2d/0x40
+[  962.380498]  [<ffffffff8122bf22>] vprintk_default+0x22/0x30
+[  962.380501]  [<ffffffff8140274d>] printk+0xab/0xc7
+[  962.380503]  [<ffffffff814026a2>] ? log_wakeup_reason.cold.1+0x13f/0x13f
+[  962.380506]  [<ffffffff82a9545b>] do_replace.cold.28+0x17/0x54
+[  962.380508]  [<ffffffff829d9b40>] ? do_replace_finish+0x2060/0x2060
+[  962.380510]  [<ffffffff81b86e9d>] ? cap_capable+0x16d/0x1c0
+[  962.380513]  [<ffffffff8112795f>] ? ns_capable_common+0x12f/0x160
+[  962.380515]  [<ffffffff829d9f29>] do_ebt_set_ctl+0xd9/0x110
+[  962.380518]  [<ffffffff8242ca22>] nf_setsockopt+0x72/0xd0
+[  962.380520]  [<ffffffff826696df>] ip_setsockopt+0x9f/0xb0
+[  962.380522]  [<ffffffff8271161f>] udp_setsockopt+0x4f/0x90
+[  962.380525]  [<ffffffff8228e5cf>] sock_common_setsockopt+0x9f/0xe0
+[  962.380527]  [<ffffffff8228b843>] SyS_setsockopt+0x163/0x250
+[  962.380530]  [<ffffffff810b9391>] ? __do_page_fault+0x361/0x8c0
+[  962.380532]  [<ffffffff8228b6e0>] ? SyS_recv+0x40/0x40
+[  962.380534]  [<ffffffff81201f1f>] ? up_read+0x1f/0x40
+[  962.380537]  [<ffffffff82ab1c98>] ? retint_user+0x18/0x3c
+[  962.380543]  [<ffffffff81002297>] ? trace_hardirqs_on_thunk+0x17/0x19
+[  962.380563]  [<ffffffff82ab1121>] entry_SYSCALL_64_fastpath+0x1e/0x9a
+[  962.380569] Code: 24 c1 00 00 00 49 8d 7c 24 38 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 d3 e3 80 3c 02 00 75 17 41 03 5c 24 38 89 da ec <5b> 0f b6 c0 41 5c 5d c3 e8 03 52 60 ff eb c2 e8 8c 52 60 ff eb 
+[  962.380571] NMI backtrace for cpu 1
+[  962.380574] CPU: 1 PID: 19 Comm: khungtaskd Not tainted 4.4.132+ #53
+[  962.380577] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
+[  962.380580] task: ffff8801d9dc2f80 ti: ffff8801d9f00000 task.ti: ffff8801d9f00000
+[  962.380583] RIP: 0010:[<ffffffff810adcba>]  [<ffffffff810adcba>] native_write_msr_safe+0xa/0x10
+[  962.380585] RSP: 0018:ffff8801d9f07c80  EFLAGS: 00000002
+[  962.380588] RAX: 0000000000000400 RBX: 0000000000000001 RCX: 0000000000000830
+[  962.380591] RDX: 0000000000000001 RSI: 0000000000000400 RDI: 0000000000000830
+[  962.380594] RBP: ffff8801d9f07c80 R08: 0000000000000001 R09: 0000000000000000
+[  962.380596] R10: 0000000000000001 R11: 0000000000000001 R12: 0000000000000007
+[  962.380599] R13: fffffbfff06cda66 R14: dffffc0000000000 R15: ffffffff83671400
+[  962.380602] FS:  0000000000000000(0000) GS:ffff8801db700000(0000) knlGS:0000000000000000
+[  962.380604] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
+[  962.380607] CR2: ffffffffff600400 CR3: 00000000b9e24000 CR4: 0000000000160630
+[  962.380610] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
+[  962.380613] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
+[  962.380614] Stack:
+[  962.380617]  ffff8801d9f07ce0 ffffffff810a3bc3 ffffffff00000010 0000000000000286
+[  962.380619]  0000000000000400 0000000000000001 0008000081d39360 ffffffff83267340
+[  962.380622]  ffffffff83671400 0000000000000003 fffffbfff06cda66 0000000000000040
+[  962.380624] Call Trace:
+[  962.380626]  [<ffffffff810a3bc3>] __x2apic_send_IPI_mask+0x123/0x1b0
+[  962.380629]  [<ffffffff810a3d23>] x2apic_send_IPI_mask+0x13/0x20
+[  962.380631]  [<ffffffff81099fb6>] nmi_raise_cpu_backtrace+0x66/0x80
+[  962.380634]  [<ffffffff81cffaa2>] nmi_trigger_all_cpu_backtrace.cold.3+0x70/0xad
+[  962.380636]  [<ffffffff811aacc9>] ? show_state_filter+0x1b9/0x270
+[  962.380639]  [<ffffffff81099f50>] ? irq_force_complete_move+0x350/0x350
+[  962.380642]  [<ffffffff8109a069>] arch_trigger_all_cpu_backtrace+0x19/0x20
+[  962.380644]  [<ffffffff81407154>] watchdog.cold.1+0xdd/0xf8
+[  962.380646]  [<ffffffff8131fdd8>] ? watchdog+0xb8/0x960
+[  962.380649]  [<ffffffff8117199d>] kthread+0x26d/0x310
+[  962.380651]  [<ffffffff8131fd20>] ? reset_hung_task_detector+0x20/0x20
+[  962.380654]  [<ffffffff81171730>] ? kthread_create_on_node+0x490/0x490
+[  962.380656]  [<ffffffff81171730>] ? kthread_create_on_node+0x490/0x490
+[  962.380659]  [<ffffffff82ab1505>] ret_from_fork+0x55/0x80
+[  962.380661]  [<ffffffff81171730>] ? kthread_create_on_node+0x490/0x490
+[  962.380667] Code: 00 55 89 f9 48 89 e5 0f 32 31 ff 48 c1 e2 20 89 3e 5d 48 09 d0 c3 90 66 2e 0f 1f 84 00 00 00 00 00 55 89 f0 89 f9 48 89 e5 0f 30 <31> c0 5d c3 66 90 55 89 f9 48 89 e5 0f 33 48 c1 e2 20 5d 48 09 
+[  962.380756] Kernel panic - not syncing: hung_task: blocked tasks
+[  962.380762] CPU: 1 PID: 19 Comm: khungtaskd Not tainted 4.4.132+ #53
+[  962.380765] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
+[  962.380773]  0000000000000001 ffff8801d9f07cb8 ffffffff81cf4f9d ffffffff82c7c980
+[  962.380779]  ffff8800b5584a58 dffffc0000000000 0000000000000003 7fffffffffffffff
+[  962.380787]  ffff8801d9f07d78 ffffffff813fba15 0000000041b58ab3 ffffffff830a787d
+[  962.380788] Call Trace:
+[  962.380797]  [<ffffffff81cf4f9d>] dump_stack+0xc1/0x124
+[  962.380803]  [<ffffffff813fba15>] panic+0x19a/0x355
+[  962.380809]  [<ffffffff813fb87b>] ? add_taint.cold.5+0x16/0x16
+[  962.380816]  [<ffffffff81cff8f6>] ? nmi_trigger_all_cpu_backtrace+0x386/0x480
+[  962.380821]  [<ffffffff811aac07>] ? show_state_filter+0xf7/0x270
+[  962.380829]  [<ffffffff81407165>] watchdog.cold.1+0xee/0xf8
+[  962.380835]  [<ffffffff8131fdd8>] ? watchdog+0xb8/0x960
+[  962.380842]  [<ffffffff8117199d>] kthread+0x26d/0x310
+[  962.380848]  [<ffffffff8131fd20>] ? reset_hung_task_detector+0x20/0x20
+[  962.380854]  [<ffffffff81171730>] ? kthread_create_on_node+0x490/0x490
+[  962.380862]  [<ffffffff81171730>] ? kthread_create_on_node+0x490/0x490
+[  962.380869]  [<ffffffff82ab1505>] ret_from_fork+0x55/0x80
+[  962.380875]  [<ffffffff81171730>] ? kthread_create_on_node+0x490/0x490
+[  962.382264] Dumping ftrace buffer:
+[  962.382299]    (ftrace buffer empty)
+[  962.383006] Kernel Offset: disabled
diff --git a/pkg/report/testdata/linux/report/255 b/pkg/report/testdata/linux/report/255
new file mode 100644
index 000000000..a33925fcb
--- /dev/null
+++ b/pkg/report/testdata/linux/report/255
@@ -0,0 +1,165 @@
+TITLE: INFO: task hung in console_device
+
+[  722.253714] INFO: task init:1 blocked for more than 120 seconds.
+[  722.253718]       Not tainted 4.4.135-g98b6097 #58
+[  722.253720] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
+[  722.253739] init            D ffff8801d99b7570 24064     1      0 0x00000004
+[  722.253809]  ffff8801d99b7570 ffff8801d99a88e0 000000000000017c ffff8801d99a8902
+[  722.253817]  ffff8801d99a8900 ffff8801db31fdb8 ffff8801db31fde0 ffff8801db31f4d8
+[  722.253826]  ffff8801db31f4c0 ffff8801d9a09800 ffff8801d99a8000 0000000000000000
+[  722.253827] Call Trace:
+[  722.253882]  [<ffffffff838b476a>] schedule+0x7a/0x1b0
+[  722.253912]  [<ffffffff838bfb81>] schedule_timeout+0x481/0x8b0
+[  722.253919]  [<ffffffff838bf700>] ? usleep_range+0x140/0x140
+[  722.253958]  [<ffffffff81517a5b>] ? do_dentry_open+0x68b/0xbc0
+[  722.253996]  [<ffffffff8122e4c7>] ? mark_held_locks+0xc7/0x130
+[  722.254003]  [<ffffffff838c1cc7>] ? _raw_spin_unlock_irq+0x27/0x50
+[  722.254015]  [<ffffffff8122e8bb>] ? trace_hardirqs_on_caller+0x38b/0x590
+[  722.254021]  [<ffffffff838bd235>] __down+0x125/0x1d0
+[  722.254028]  [<ffffffff838bd110>] ? ww_mutex_unlock+0x300/0x300
+[  722.254035]  [<ffffffff8122562e>] down+0x5e/0x80
+[  722.254043]  [<ffffffff8125853c>] console_lock+0x2c/0x80
+[  722.254064]  [<ffffffff814f4e94>] ? kmem_cache_alloc_trace+0x104/0x2c0
+[  722.254070]  [<ffffffff8125dc8c>] console_device+0x1c/0xc0
+[  722.254095]  [<ffffffff8204cfdf>] tty_open+0x8bf/0xf00
+[  722.254102]  [<ffffffff8204c720>] ? tty_init_dev+0x430/0x430
+[  722.254112]  [<ffffffff81529477>] ? chrdev_open+0xc7/0x4c0
+[  722.254119]  [<ffffffff8204c720>] ? tty_init_dev+0x430/0x430
+[  722.254125]  [<ffffffff815295dd>] chrdev_open+0x22d/0x4c0
+[  722.254131]  [<ffffffff815293b0>] ? cdev_put.part.0+0x50/0x50
+[  722.254137]  [<ffffffff81517a5b>] do_dentry_open+0x68b/0xbc0
+[  722.254145]  [<ffffffff8153c0ab>] ? __inode_permission2+0x9b/0x240
+[  722.254151]  [<ffffffff815293b0>] ? cdev_put.part.0+0x50/0x50
+[  722.254157]  [<ffffffff8151b08a>] vfs_open+0x12a/0x210
+[  722.254164]  [<ffffffff8153d826>] ? may_open.isra.40+0x156/0x240
+[  722.254171]  [<ffffffff8154c12e>] path_openat+0x4ee/0x3a10
+[  722.254195]  [<ffffffff81eb7719>] ? depot_save_stack+0x1c9/0x610
+[  722.254203]  [<ffffffff8154bc40>] ? path_lookupat.isra.36+0x410/0x410
+[  722.254210]  [<ffffffff8154fb67>] ? getname_flags+0xc7/0x580
+[  722.254216]  [<ffffffff81550039>] ? getname+0x19/0x20
+[  722.254222]  [<ffffffff8151b893>] ? do_sys_open+0x203/0x610
+[  722.254228]  [<ffffffff8151bccd>] ? SyS_open+0x2d/0x40
+[  722.254235]  [<ffffffff838c27a5>] ? entry_SYSCALL_64_fastpath+0x22/0x9e
+[  722.254243]  [<ffffffff8122f030>] ? debug_check_no_locks_freed+0x210/0x210
+[  722.254250]  [<ffffffff81229682>] ? __lock_is_held+0xa2/0xf0
+[  722.254258]  [<ffffffff81552367>] do_filp_open+0x197/0x270
+[  722.254265]  [<ffffffff815521d0>] ? user_path_mountpoint_at+0x70/0x70
+[  722.254272]  [<ffffffff838c1c3c>] ? _raw_spin_unlock+0x2c/0x50
+[  722.254284]  [<ffffffff81579f83>] ? __alloc_fd+0x1f3/0x4a0
+[  722.254291]  [<ffffffff8151b9ac>] do_sys_open+0x31c/0x610
+[  722.254297]  [<ffffffff8151b690>] ? filp_open+0x70/0x70
+[  722.254318]  [<ffffffff81160650>] ? sigprocmask+0x290/0x290
+[  722.254324]  [<ffffffff8151bccd>] SyS_open+0x2d/0x40
+[  722.254331]  [<ffffffff838c27a5>] entry_SYSCALL_64_fastpath+0x22/0x9e
+[  722.254336] 1 lock held by init/1:
+[  722.254351]  #0:  (tty_mutex){+.+.+.}, at: [<ffffffff8204cc5e>] tty_open+0x53e/0xf00
+[  722.254355] Sending NMI to all CPUs:
+[  722.255664] NMI backtrace for cpu 0
+[  722.255667] CPU: 0 PID: 3960 Comm: syz-executor617 Not tainted 4.4.135-g98b6097 #58
+[  722.255671] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
+[  722.255674] task: ffff8800bb13e000 task.stack: ffff8800b9b08000
+[  722.255677] RIP: 0010:[<ffffffff82083f5b>]  [<ffffffff82083f5b>] io_serial_in+0x6b/0x90
+[  722.255680] RSP: 0018:ffff8800b9b0f7f0  EFLAGS: 00000002
+[  722.255682] RAX: dffffc0000000000 RBX: 00000000000003fd RCX: 0000000000000000
+[  722.255685] RDX: 00000000000003fd RSI: ffffffff82083f01 RDI: ffffffff862aa4f8
+[  722.255688] RBP: ffff8800b9b0f800 R08: 0000000000000001 R09: 0000000000000000
+[  722.255691] R10: 0000000000000001 R11: ffffffff858ed15a R12: ffffffff862aa4c0
+[  722.255694] R13: 0000000000000020 R14: fffffbfff0c554df R15: fffffbfff0c554a1
+[  722.255698] FS:  0000000002477880(0063) GS:ffff8801db200000(0000) knlGS:0000000000000000
+[  722.255700] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
+[  722.255703] CR2: 00000000006cf090 CR3: 00000000b10e2000 CR4: 00000000001606f0
+[  722.255706] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
+[  722.255709] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
+[  722.255711] Stack:
+[  722.255714]  ffffffff862aa4c0 0000000000002710 ffff8800b9b0f850 ffffffff82085abf
+[  722.255717]  ffffffff81e37875 ffffffff862aa508 ffffffff862aa6fa ffffffff862aa4c0
+[  722.255720]  0000000000000020 ffffffff82085c10 dffffc0000000000 0000000000000020
+[  722.255722] Call Trace:
+[  722.255724]  [<ffffffff82085abf>] wait_for_xmitr+0x8f/0x1e0
+[  722.255727]  [<ffffffff81e37875>] ? vsnprintf+0x1a5/0x18e0
+[  722.255730]  [<ffffffff82085c10>] ? wait_for_xmitr+0x1e0/0x1e0
+[  722.255732]  [<ffffffff82085c2f>] serial8250_console_putchar+0x1f/0x60
+[  722.255735]  [<ffffffff820700c9>] uart_console_write+0x59/0xf0
+[  722.255738]  [<ffffffff82090289>] serial8250_console_write+0x539/0x830
+[  722.255741]  [<ffffffff8208fd50>] ? exar_handle_irq+0x1c0/0x1c0
+[  722.255743]  [<ffffffff81e39240>] ? scnprintf+0x110/0x110
+[  722.255746]  [<ffffffff81003017>] ? trace_hardirqs_on_thunk+0x17/0x19
+[  722.255749]  [<ffffffff8207ec10>] ? univ8250_console_setup+0xf0/0xf0
+[  722.255752]  [<ffffffff8207ec6f>] univ8250_console_write+0x5f/0x70
+[  722.255755]  [<ffffffff81259f1f>] call_console_drivers.constprop.28+0x1ef/0x3f0
+[  722.255757]  [<ffffffff8125cbf5>] console_unlock+0x605/0xa10
+[  722.255760]  [<ffffffff8125d51e>] vprintk_emit+0x51e/0x840
+[  722.255762]  [<ffffffff8125d868>] vprintk+0x28/0x30
+[  722.255765]  [<ffffffff8125d88d>] vprintk_default+0x1d/0x30
+[  722.255767]  [<ffffffff814152a8>] printk+0xaf/0xd7
+[  722.255770]  [<ffffffff814151f9>] ? log_wakeup_reason.cold.1+0x13f/0x13f
+[  722.255773]  [<ffffffff82dd0fcc>] binder_ioctl.cold.83+0x91/0x132
+[  722.255776]  [<ffffffff82d7cff0>] ? binder_ioctl_write_read.isra.47+0x920/0x920
+[  722.255779]  [<ffffffff8146ccd7>] ? vm_mmap_pgoff+0x177/0x1b0
+[  722.255782]  [<ffffffff82d7cff0>] ? binder_ioctl_write_read.isra.47+0x920/0x920
+[  722.255784]  [<ffffffff81559bbf>] do_vfs_ioctl+0x63f/0xf40
+[  722.255787]  [<ffffffff81559580>] ? ioctl_preallocate+0x1f0/0x1f0
+[  722.255790]  [<ffffffff815229d0>] ? fput+0x20/0x150
+[  722.255792]  [<ffffffff814ab7c8>] ? SyS_mmap_pgoff+0xd8/0x550
+[  722.255795]  [<ffffffff81c4dccf>] ? security_file_ioctl+0x8f/0xc0
+[  722.255797]  [<ffffffff8155a54f>] SyS_ioctl+0x8f/0xc0
+[  722.255800]  [<ffffffff838c27a5>] entry_SYSCALL_64_fastpath+0x22/0x9e
+[  722.255806] Code: 24 c1 00 00 00 49 8d 7c 24 38 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 d3 e3 80 3c 02 00 75 17 41 03 5c 24 38 89 da ec <5b> 0f b6 c0 41 5c 5d c3 e8 78 57 47 ff eb c2 e8 d1 57 47 ff eb 
+[  722.255809] NMI backtrace for cpu 1
+[  722.255811] CPU: 1 PID: 492 Comm: khungtaskd Not tainted 4.4.135-g98b6097 #58
+[  722.255815] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
+[  722.255818] task: ffff8801d8ca0000 task.stack: ffff8801d8d20000
+[  722.255821] RIP: 0010:[<ffffffff810bfeb6>]  [<ffffffff810bfeb6>] flat_send_IPI_mask+0xf6/0x1a0
+[  722.255824] RSP: 0018:ffff8801d8d27cc8  EFLAGS: 00000046
+[  722.255827] RAX: 0000000003000000 RBX: 0000000000000c00 RCX: 0000000000000000
+[  722.255830] RDX: 0000000000000c00 RSI: 0000000000000000 RDI: ffffffffff5fb300
+[  722.255833] RBP: ffff8801d8d27cf0 R08: 0000000000000001 R09: 0000000000000000
+[  722.255836] R10: 0000000000000001 R11: 0000000000000001 R12: 0000000000000246
+[  722.255839] R13: 0000000000000003 R14: 0000000000000002 R15: ffffffff8446f7a0
+[  722.255842] FS:  0000000000000000(0000) GS:ffff8801db300000(0000) knlGS:0000000000000000
+[  722.255845] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
+[  722.255848] CR2: 0000000000ec0000 CR3: 00000000b2316000 CR4: 00000000001606f0
+[  722.255851] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
+[  722.255854] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
+[  722.255856] Stack:
+[  722.255859]  ffffffff8446f7a0 ffffffff84a18e60 0000000000000007 fffffbfff0942c7c
+[  722.255862]  0000000000000040 ffff8801d8d27d10 ffffffff810b5e71 ffffffff83c0b560
+[  722.255865]  0000000000000003 ffff8801d8d27d68 ffffffff81e19da3 ffffffff8140dcef
+[  722.255867] Call Trace:
+[  722.255869]  [<ffffffff810b5e71>] nmi_raise_cpu_backtrace+0x61/0x80
+[  722.255872]  [<ffffffff81e19da3>] nmi_trigger_all_cpu_backtrace.cold.4+0x70/0xad
+[  722.255875]  [<ffffffff8140dcef>] ? print_lock+0x9f/0xa2
+[  722.255878]  [<ffffffff810b5e10>] ? irq_force_complete_move+0x350/0x350
+[  722.255881]  [<ffffffff810b5f14>] arch_trigger_all_cpu_backtrace+0x14/0x20
+[  722.255883]  [<ffffffff8141a3d9>] watchdog.cold.1+0xd3/0xee
+[  722.255886]  [<ffffffff81358e40>] ? watchdog+0xb0/0x9a0
+[  722.255889]  [<ffffffff81190958>] kthread+0x268/0x300
+[  722.255891]  [<ffffffff81358d90>] ? reset_hung_task_detector+0x20/0x20
+[  722.255894]  [<ffffffff811906f0>] ? kthread_create_on_node+0x400/0x400
+[  722.255897]  [<ffffffff811906f0>] ? kthread_create_on_node+0x400/0x400
+[  722.255900]  [<ffffffff838c2bd5>] ret_from_fork+0x55/0x80
+[  722.255902]  [<ffffffff811906f0>] ? kthread_create_on_node+0x400/0x400
+[  722.255908] Code: b3 5f ff f6 c4 10 75 e2 44 89 e8 c1 e0 18 89 04 25 10 b3 5f ff 44 89 f2 09 da 80 cf 04 41 83 fe 02 0f 44 d3 89 14 25 00 b3 5f ff <41> f7 c4 00 02 00 00 75 1a 4c 89 e7 57 9d 0f 1f 44 00 00 e8 72 
+[  722.256030] Kernel panic - not syncing: hung_task: blocked tasks
+[  722.256036] CPU: 1 PID: 492 Comm: khungtaskd Not tainted 4.4.135-g98b6097 #58
+[  722.256040] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
+[  722.256048]  0000000000000000 c6b8d4f7a3c1f5c6 ffff8801d8d27cb8 ffffffff81e0ed2d
+[  722.256056]  ffffffff83a837c0 0000000000000003 7fffffffffffffff 00000000003fffff
+[  722.256064]  dffffc0000000000 ffff8801d8d27d78 ffffffff8140a104 0000000041b58ab3
+[  722.256065] Call Trace:
+[  722.256072]  [<ffffffff81e0ed2d>] dump_stack+0xc1/0x124
+[  722.256079]  [<ffffffff8140a104>] panic+0x19e/0x38d
+[  722.256085]  [<ffffffff81409f66>] ? add_taint.cold.4+0x16/0x16
+[  722.256092]  [<ffffffff81e19bd5>] ? nmi_trigger_all_cpu_backtrace+0x395/0x488
+[  722.256099]  [<ffffffff81e19bd5>] ? nmi_trigger_all_cpu_backtrace+0x395/0x488
+[  722.256105]  [<ffffffff8141a3ea>] watchdog.cold.1+0xe4/0xee
+[  722.256112]  [<ffffffff81358e40>] ? watchdog+0xb0/0x9a0
+[  722.256118]  [<ffffffff81190958>] kthread+0x268/0x300
+[  722.256126]  [<ffffffff81358d90>] ? reset_hung_task_detector+0x20/0x20
+[  722.256133]  [<ffffffff811906f0>] ? kthread_create_on_node+0x400/0x400
+[  722.256140]  [<ffffffff811906f0>] ? kthread_create_on_node+0x400/0x400
+[  722.256147]  [<ffffffff838c2bd5>] ret_from_fork+0x55/0x80
+[  722.256154]  [<ffffffff811906f0>] ? kthread_create_on_node+0x400/0x400
+[  722.260296] Dumping ftrace buffer:
+[  722.260319]    (ftrace buffer empty)
+[  722.260321] Kernel Offset: disabled