INFO: rcu_sched self-detected stall on CPU
	1-...!: (124999 ticks this GP) idle=3da/1/4611686018427387906 softirq=26488/26488 fqs=2 
	 (t=125000 jiffies g=14715 c=14714 q=142)
rcu_sched kthread starved for 124992 jiffies! g14715 c14714 f0x0 RCU_GP_WAIT_FQS(3) ->state=0x0 ->cpu=0
RCU grace-period kthread stack dump:
rcu_sched       R  running task    23896     9      2 0x80000000
Call Trace:
 context_switch kernel/sched/core.c:2859 [inline]
 __schedule+0x801/0x1e30 kernel/sched/core.c:3501
 schedule+0xef/0x430 kernel/sched/core.c:3545
 schedule_timeout+0x138/0x240 kernel/time/timer.c:1801
 rcu_gp_kthread+0x6b5/0x1940 kernel/rcu/tree.c:2231
 kthread+0x345/0x410 kernel/kthread.c:240
 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:412
NMI backtrace for cpu 1
CPU: 1 PID: 4574 Comm: syz-executor3 Not tainted 4.17.0-rc7+ #38
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1b9/0x294 lib/dump_stack.c:113
 nmi_cpu_backtrace.cold.4+0x19/0xce lib/nmi_backtrace.c:103
 nmi_trigger_cpumask_backtrace+0x151/0x192 lib/nmi_backtrace.c:62
 arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:38
 trigger_single_cpu_backtrace include/linux/nmi.h:156 [inline]
 rcu_dump_cpu_stacks+0x175/0x1c2 kernel/rcu/tree.c:1376
 print_cpu_stall kernel/rcu/tree.c:1525 [inline]
 check_cpu_stall.isra.61.cold.80+0x36c/0x59a kernel/rcu/tree.c:1593
 __rcu_pending kernel/rcu/tree.c:3356 [inline]
 rcu_pending kernel/rcu/tree.c:3401 [inline]
 rcu_check_callbacks+0x21b/0xad0 kernel/rcu/tree.c:2763
 update_process_times+0x2d/0x70 kernel/time/timer.c:1636
 tick_sched_handle+0x9f/0x180 kernel/time/tick-sched.c:164
 tick_sched_timer+0x45/0x130 kernel/time/tick-sched.c:1274
 __run_hrtimer kernel/time/hrtimer.c:1398 [inline]
 __hrtimer_run_queues+0x3e3/0x10a0 kernel/time/hrtimer.c:1460
 hrtimer_interrupt+0x2f3/0x750 kernel/time/hrtimer.c:1518
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1025 [inline]
 smp_apic_timer_interrupt+0x15d/0x710 arch/x86/kernel/apic/apic.c:1050
 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:863
 </IRQ>
RIP: 0010:__read_once_size include/linux/compiler.h:188 [inline]
RIP: 0010:check_kcov_mode kernel/kcov.c:69 [inline]
RIP: 0010:__sanitizer_cov_trace_pc+0x26/0x50 kernel/kcov.c:101
RSP: 0018:ffff8801a4dff8f8 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13
RAX: ffff8801a4df23c0 RBX: 1ffff100349bff24 RCX: ffffffff81c66c14
RDX: 0000000000000000 RSI: ffffffff81c66ca5 RDI: ffff8801a4dffc28
RBP: ffff8801a4dff8f8 R08: ffff8801a4df23c0 R09: ffffed0039bab754
R10: ffffed0039bab754 R11: ffff8801cdd5baa3 R12: ffff8801a4dffc10
R13: ffff8801cdd5ba20 R14: ffff8801a4dffc18 R15: ffff8801a4dff9c0
 list_empty include/linux/list.h:203 [inline]
 select_collect+0x175/0x5f0 fs/dcache.c:1465
 d_walk+0x3c3/0xc80 fs/dcache.c:1276
 shrink_dcache_parent+0x179/0x230 fs/dcache.c:1486
 vfs_rmdir+0x202/0x470 fs/namei.c:3850
 do_rmdir+0x523/0x610 fs/namei.c:3911
 __do_sys_rmdir fs/namei.c:3929 [inline]
 __se_sys_rmdir fs/namei.c:3927 [inline]
 __x64_sys_rmdir+0x36/0x40 fs/namei.c:3927
 do_syscall_64+0x1b1/0x800 arch/x86/entry/common.c:287
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x455767
RSP: 002b:00007ffe6f8346a8 EFLAGS: 00000202 ORIG_RAX: 0000000000000054
RAX: ffffffffffffffda RBX: 0000000000000065 RCX: 0000000000455767
RDX: 0000000000000000 RSI: 00007ffe6f836450 RDI: 00007ffe6f836450
RBP: 00007ffe6f836450 R08: 0000000000000000 R09: 0000000000000001
R10: 000000000000000a R11: 0000000000000202 R12: 0000000000db2940
R13: 0000000000000000 R14: 00000000000001a4 R15: 00000000000186ae