rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	1-...!: (1 ticks this GP) idle=832/1/0x4000000000000002 softirq=46870/46870 fqs=0 
	(t=11135 jiffies g=43293 q=291)
rcu: rcu_preempt kthread starved for 11135 jiffies! g43293 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->cpu=1
rcu: RCU grace-period kthread stack dump:
rcu_preempt     I29384    10      2 0x80004000
Call Trace:
 schedule+0xd0/0x2a0 kernel/sched/core.c:4154
 schedule_timeout+0x474/0xba0 kernel/time/timer.c:1895
 rcu_gp_fqs_loop kernel/rcu/tree.c:1658 [inline]
 rcu_gp_kthread+0x9d9/0x17d0 kernel/rcu/tree.c:1818
 kthread+0x357/0x430 kernel/kthread.c:255
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352
NMI backtrace for cpu 1
CPU: 1 PID: 2797 Comm: kworker/1:13 Not tainted 5.6.0-rc6-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: rcu_gp process_srcu
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x188/0x20d lib/dump_stack.c:118
 nmi_cpu_backtrace.cold+0x70/0xb1 lib/nmi_backtrace.c:101
 nmi_trigger_cpumask_backtrace+0x231/0x27e lib/nmi_backtrace.c:62
 trigger_single_cpu_backtrace include/linux/nmi.h:164 [inline]
 rcu_dump_cpu_stacks+0x169/0x1b3 kernel/rcu/tree_stall.h:254
 print_cpu_stall kernel/rcu/tree_stall.h:475 [inline]
 check_cpu_stall kernel/rcu/tree_stall.h:549 [inline]
 rcu_pending kernel/rcu/tree.c:3030 [inline]
 rcu_sched_clock_irq.cold+0x518/0xc55 kernel/rcu/tree.c:2276
 update_process_times+0x25/0x60 kernel/time/timer.c:1726
 tick_sched_handle+0x9b/0x180 kernel/time/tick-sched.c:171
 tick_sched_timer+0x4e/0x140 kernel/time/tick-sched.c:1314
 __run_hrtimer kernel/time/hrtimer.c:1517 [inline]
 __hrtimer_run_queues+0x32c/0xdd0 kernel/time/hrtimer.c:1579
 hrtimer_interrupt+0x312/0x770 kernel/time/hrtimer.c:1641
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1119 [inline]
 smp_apic_timer_interrupt+0x15b/0x600 arch/x86/kernel/apic/apic.c:1144
 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:829
 </IRQ>
RIP: 0010:preempt_schedule_irq+0xa6/0x150 kernel/sched/core.c:4337
Code: 00 00 e8 bd a5 93 f9 e8 f8 5e bc f9 4c 89 e8 48 c1 e8 03 80 3c 18 00 75 7a 48 83 3d 43 82 b8 01 00 74 6c fb 66 0f 1f 44 00 00 <bf> 01 00 00 00 e8 c0 d1 ff ff 48 c7 c0 c8 b4 73 89 48 c1 e8 03 80
RSP: 0018:ffffc9000821fb10 EFLAGS: 00000282 ORIG_RAX: ffffffffffffff13
RAX: 1ffffffff12e769a RBX: dffffc0000000000 RCX: 0000000000000006
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffff88809f688c94
RBP: ffffed1013ed1080 R08: ffff88809f688400 R09: fffffbfff180e57a
R10: fffffbfff180e579 R11: ffffffff8c072bcf R12: ffff88809f688400
R13: ffffffff8973b4d0 R14: 0000000000000000 R15: 0000000000000000
 retint_kernel+0x1b/0x2b
RIP: 0010:delay_tsc+0x2e/0xb0 arch/x86/lib/delay.c:68
Code: fd bf 01 00 00 00 41 54 55 53 e8 5d e4 95 f9 e8 68 69 d9 fb 41 89 c4 0f 01 f9 66 90 48 c1 e2 20 48 09 c2 48 89 d5 eb 16 f3 90 <bf> 01 00 00 00 e8 38 e4 95 f9 e8 43 69 d9 fb 44 39 e0 75 36 0f 01
RSP: 0018:ffffc9000821fbe0 EFLAGS: 00000286 ORIG_RAX: ffffffffffffff02
RAX: 0000000080000000 RBX: 0000013603f3b584 RCX: 0000000000000000
RDX: 0000000000000001 RSI: ffffffff83925d6f RDI: 0000000000000001
RBP: 0000013603f38e2f R08: ffff88809f688400 R09: 0000000000000040
R10: 0000000000000040 R11: ffffffff8985f667 R12: 0000000000000001
R13: 0000000000002ced R14: dffffc0000000000 R15: 00000000000014e0
 try_check_zero+0x1fb/0x340 kernel/rcu/srcutree.c:705
 srcu_advance_state kernel/rcu/srcutree.c:1143 [inline]
 process_srcu+0x31d/0xde0 kernel/rcu/srcutree.c:1238
 process_one_work+0x94b/0x1690 kernel/workqueue.c:2266
 worker_thread+0x96/0xe20 kernel/workqueue.c:2412
 kthread+0x357/0x430 kernel/kthread.c:255
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352