kworker/dying (3778) used greatest stack depth: 16128 bytes left INFO: task khugepaged:753 blocked for more than 120 seconds. Not tainted 4.15.0-rc8+ #2 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. khugepaged D22864 753 2 0x80000000 Call Trace: context_switch kernel/sched/core.c:2799 [inline] __schedule+0x8eb/0x2060 kernel/sched/core.c:3375 schedule+0xf5/0x430 kernel/sched/core.c:3434 __rwsem_down_read_failed_common kernel/locking/rwsem-xadd.c:269 [inline] rwsem_down_read_failed+0x401/0x6e0 kernel/locking/rwsem-xadd.c:286 call_rwsem_down_read_failed+0x18/0x30 arch/x86/lib/rwsem.S:94 __down_read arch/x86/include/asm/rwsem.h:83 [inline] down_read+0xa4/0x150 kernel/locking/rwsem.c:26 khugepaged_scan_mm_slot mm/khugepaged.c:1677 [inline] khugepaged_do_scan mm/khugepaged.c:1810 [inline] khugepaged+0x9d8/0x1400 mm/khugepaged.c:1855 kthread+0x33c/0x400 kernel/kthread.c:238 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:541 Showing all locks held in the system: 2 locks held by khungtaskd/747: #0: (rcu_read_lock){....}, at: [<000000003450020a>] check_hung_uninterruptible_tasks kernel/hung_task.c:175 [inline] #0: (rcu_read_lock){....}, at: [<000000003450020a>] watchdog+0x1c5/0xd60 kernel/hung_task.c:249 #1: (tasklist_lock){.+.+}, at: [<000000005e6ded07>] debug_show_all_locks+0xd3/0x400 kernel/locking/lockdep.c:4464 1 lock held by khugepaged/753: #0: (&mm->mmap_sem){++++}, at: [<000000007a9397c7>] khugepaged_scan_mm_slot mm/khugepaged.c:1677 [inline] #0: (&mm->mmap_sem){++++}, at: [<000000007a9397c7>] khugepaged_do_scan mm/khugepaged.c:1810 [inline] #0: (&mm->mmap_sem){++++}, at: [<000000007a9397c7>] khugepaged+0x9d8/0x1400 mm/khugepaged.c:1855 1 lock held by rsyslogd/3499: #0: (&f->f_pos_lock){+.+.}, at: [<000000005abc974e>] spin_lock include/linux/spinlock.h:310 [inline] #0: (&f->f_pos_lock){+.+.}, at: [<000000005abc974e>] double_lock_hb kernel/futex.c:1516 [inline] #0: (&f->f_pos_lock){+.+.}, at: [<000000005abc974e>] futex_wake_op kernel/futex.c:1654 [inline] #0: (&f->f_pos_lock){+.+.}, at: [<000000005abc974e>] do_futex+0x10bb/0x22a0 kernel/futex.c:3555 2 locks held by getty/3621: #0: (&tty->ldisc_sem){++++}, at: [<00000000246c9a1d>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000b5fa308c>] n_tty_read+0x2ef/0x1a00 drivers/tty/n_tty.c:2131 2 locks held by getty/3622: #0: (&tty->ldisc_sem){++++}, at: [<00000000246c9a1d>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000b5fa308c>] n_tty_read+0x2ef/0x1a00 drivers/tty/n_tty.c:2131 2 locks held by getty/3623: #0: (&tty->ldisc_sem){++++}, at: [<00000000246c9a1d>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000b5fa308c>] n_tty_read+0x2ef/0x1a00 drivers/tty/n_tty.c:2131 2 locks held by getty/3624: #0: (&tty->ldisc_sem){++++}, at: [<00000000246c9a1d>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000b5fa308c>] n_tty_read+0x2ef/0x1a00 drivers/tty/n_tty.c:2131 2 locks held by getty/3625: #0: (&tty->ldisc_sem){++++}, at: [<00000000246c9a1d>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000b5fa308c>] n_tty_read+0x2ef/0x1a00 drivers/tty/n_tty.c:2131 2 locks held by getty/3626: #0: (&tty->ldisc_sem){++++}, at: [<00000000246c9a1d>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000b5fa308c>] n_tty_read+0x2ef/0x1a00 drivers/tty/n_tty.c:2131 2 locks held by getty/3627: #0: (&tty->ldisc_sem){++++}, at: [<00000000246c9a1d>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000b5fa308c>] n_tty_read+0x2ef/0x1a00 drivers/tty/n_tty.c:2131 1 lock held by syz-executor3/3491: #0: (&mm->mmap_sem){++++}, at: [<00000000148d98a0>] exit_mm kernel/exit.c:510 [inline] #0: (&mm->mmap_sem){++++}, at: [<00000000148d98a0>] do_exit+0x4b0/0x1ad0 kernel/exit.c:852 1 lock held by syz-executor3/3497: #0: (&mm->mmap_sem){++++}, at: [<00000000148d98a0>] exit_mm kernel/exit.c:510 [inline] #0: (&mm->mmap_sem){++++}, at: [<00000000148d98a0>] do_exit+0x4b0/0x1ad0 kernel/exit.c:852 1 lock held by syz-executor3/3512: #0: (&mm->mmap_sem){++++}, at: [<00000000148d98a0>] exit_mm kernel/exit.c:510 [inline] #0: (&mm->mmap_sem){++++}, at: [<00000000148d98a0>] do_exit+0x4b0/0x1ad0 kernel/exit.c:852 1 lock held by syz-executor3/3513: #0: (&mm->mmap_sem){++++}, at: [<00000000148d98a0>] exit_mm kernel/exit.c:510 [inline] #0: (&mm->mmap_sem){++++}, at: [<00000000148d98a0>] do_exit+0x4b0/0x1ad0 kernel/exit.c:852 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 747 Comm: khungtaskd Not tainted 4.15.0-rc8+ #2 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x194/0x257 lib/dump_stack.c:53 nmi_cpu_backtrace+0x1d2/0x210 lib/nmi_backtrace.c:103 nmi_trigger_cpumask_backtrace+0x122/0x180 lib/nmi_backtrace.c:62 arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:38 trigger_all_cpu_backtrace include/linux/nmi.h:138 [inline] check_hung_task kernel/hung_task.c:132 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:190 [inline] watchdog+0x90c/0xd60 kernel/hung_task.c:249 kthread+0x33c/0x400 kernel/kthread.c:238 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:541 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 3508 Comm: syz-executor3 Not tainted 4.15.0-rc8+ #2 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:__lock_is_held+0x114/0x140 kernel/locking/lockdep.c:3743 RSP: 0018:ffff8801ce6172d0 EFLAGS: 00000082 RAX: 0000000000000000 RBX: 0000000000000282 RCX: 0000000000000000 RDX: dffffc0000000000 RSI: ffffffff86941540 RDI: ffff8801c6f04a1a RBP: ffff8801ce6172d0 R08: ffffffff81874f42 R09: 0000000000000000 R10: ffff8801ce6177d8 R11: 0000000000000001 R12: ffff8801c6f04180 R13: ffffffff86941540 R14: 00000000000002eb R15: 0000000000000000 FS: 00007f1714066700(0000) GS:ffff8801db300000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000000041b660 CR3: 00000001cddeb006 CR4: 00000000001606e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: lock_is_held_type+0x118/0x210 kernel/locking/lockdep.c:3952 lock_is_held include/linux/lockdep.h:344 [inline] ___might_sleep+0x39b/0x470 kernel/sched/core.c:6025 __might_sleep+0x95/0x190 kernel/sched/core.c:6013 __mutex_lock_common kernel/locking/mutex.c:747 [inline] __mutex_lock+0x13e/0x1a80 kernel/locking/mutex.c:893 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:908 perf_mmap+0x6b2/0x1b70 kernel/events/core.c:5280 call_mmap include/linux/fs.h:1777 [inline] mmap_region+0xa99/0x15a0 mm/mmap.c:1705 do_mmap+0x6c0/0xe00 mm/mmap.c:1483 do_mmap_pgoff include/linux/mm.h:2217 [inline] vm_mmap_pgoff+0x1de/0x280 mm/util.c:333 SYSC_mmap_pgoff mm/mmap.c:1533 [inline] SyS_mmap_pgoff+0x462/0x5f0 mm/mmap.c:1491 SYSC_mmap arch/x86/kernel/sys_x86_64.c:100 [inline] SyS_mmap+0x16/0x20 arch/x86/kernel/sys_x86_64.c:91 entry_SYSCALL_64_fastpath+0x29/0xa0 RIP: 0033:0x452f19 RSP: 002b:00007f1714065c58 EFLAGS: 00000212 ORIG_RAX: 0000000000000009 RAX: ffffffffffffffda RBX: 00007f1714066700 RCX: 0000000000452f19 RDX: 0000000000000000 RSI: 0000000000002000 RDI: 0000000020f1f000 RBP: 00007ffdd09cb4d0 R08: 0000000000000013 R09: 0000000000000000 R10: 0000000000000011 R11: 0000000000000212 R12: 0000000000000000 R13: 00007ffdd09cb44f R14: 00007f17140669c0 R15: 0000000000000007 Code: 22 83 e0 03 3b 45 c4 0f 94 c0 48 83 c4 18 5b 0f b6 c0 41 5c 41 5d 41 5e 41 5f 5d c3 31 c0 48 83 c4 18 5b 41 5c 41 5d 41 5e 41 5f <5d> c3 48 8b 7d c8 e8 91 d4 52 00 e9 2a ff ff ff e8 87 d4 52 00