rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	0-...!: (0 ticks this GP) idle=91b4/1/0x4000000000000000 softirq=40944/40944 fqs=1
rcu: 	(detected by 1, t=10502 jiffies, g=34025, q=5 ncpus=2)
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 12576 Comm: syz.1.2012 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
RIP: 0010:do_raw_spin_lock+0x19e/0x290
Code: 24 20 0e 36 e0 45 48 8b 44 24 18 4a c7 04 38 00 00 00 00 65 48 8b 05 01 bb 02 11 48 3b 44 24 60 0f 85 e4 00 00 00 48 8d 65 d8 <5b> 41 5c 41 5d 41 5e 41 5f 5d c3 cc cc cc cc cc e8 6d 03 27 03 85
RSP: 0018:ffffc90000007848 EFLAGS: 00000046
RAX: 425f3bf4cc91c300 RBX: 0000000000000000 RCX: dffffc0000000000
RDX: 0000000000000001 RSI: 0000000000000004 RDI: ffffc90000007800
RBP: ffffc90000007870 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffff52000000f00 R12: ffff88804b027a90
R13: ffff88804b027a88 R14: 1ffff11009604f52 R15: dffffc0000000000
FS:  00007f84980466c0(0000) GS:ffff8880b8613000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 000000010d176000 CR4: 00000000000006f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000082
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 <IRQ>
 _raw_spin_lock_irqsave+0xb3/0xf0
 hrtimer_try_to_cancel+0x22b/0x420
 hrtimer_cancel+0x3b/0x50
 cpu_clock_event_stop+0xd9/0x130
 __perf_event_overflow+0x580/0xe40
 perf_swevent_hrtimer+0x3c5/0x550
 __hrtimer_run_queues+0x4e0/0xc60
 hrtimer_interrupt+0x45b/0xaa0
 __sysvec_apic_timer_interrupt+0x10b/0x410
 sysvec_apic_timer_interrupt+0xa1/0xc0
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20
RIP: 0010:copy_pmd_range+0x442f/0x71d0
Code: 0f 8c 8e de ff ff 4c 89 ff e8 8d 3b 17 00 e9 81 de ff ff f3 0f 1e fa e8 bf bd b3 ff 4c 89 f7 48 8b b4 24 a0 00 00 00 48 89 da <b9> 01 00 00 00 e8 27 6f 22 00 e9 96 da ff ff f3 0f 1e fa 4c 89 ee
RSP: 0018:ffffc9000ecbf3a0 EFLAGS: 00000283
RAX: ffffffff820c0341 RBX: 80000000298e6007 RCX: 0000000000080000
RDX: 80000000298e6007 RSI: ffff888029083a80 RDI: ffff888110ad2b00
RBP: ffffc9000ecbf630 R08: ffffea0000a63987 R09: 1ffffd400014c730
R10: dffffc0000000000 R11: fffff9400014c731 R12: 00007f8496750000
R13: ffff88812b9fd810 R14: ffff888110ad2b00 R15: 0000000000000000
 copy_page_range+0xc14/0x1270
 dup_mmap+0xf57/0x1ac0
 copy_mm+0x13c/0x4b0
 copy_process+0x1706/0x3c00
 kernel_clone+0x21e/0x840
 __x64_sys_clone+0x18b/0x1e0
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f849718eba9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f8498045fe8 EFLAGS: 00000246 ORIG_RAX: 0000000000000038
RAX: ffffffffffffffda RBX: 00007f84973d5fa0 RCX: 00007f849718eba9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007f8497211e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f84973d6038 R14: 00007f84973d5fa0 R15: 00007ffde413b408
 </TASK>
rcu: rcu_preempt kthread starved for 10495 jiffies! g34025 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=1
rcu: 	Unless rcu_preempt kthread gets sufficient CPU time, OOM is now expected behavior.
rcu: RCU grace-period kthread stack dump:
task:rcu_preempt     state:R  running task     stack:26792 pid:16    tgid:16    ppid:2      task_flags:0x208040 flags:0x00004000
Call Trace:
 <TASK>
 __schedule+0x1798/0x4cc0
 schedule+0x165/0x360
 schedule_timeout+0x12b/0x270
 rcu_gp_fqs_loop+0x301/0x1540
 rcu_gp_kthread+0x99/0x390
 kthread+0x711/0x8a0
 ret_from_fork+0x439/0x7d0
 ret_from_fork_asm+0x1a/0x30
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
CPU: 1 UID: 0 PID: 40 Comm: kworker/u10:2 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
Workqueue: events_unbound toggle_allocation_gate
RIP: 0010:smp_call_function_many_cond+0xd3c/0x12d0
Code: 01 31 ff e8 56 63 0b 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 07 e8 01 5f 0b 00 eb 38 f3 90 42 0f b6 04 2b 84 c0 75 11 <41> f7 04 24 01 00 00 00 74 1e e8 e5 5e 0b 00 eb e4 44 89 e1 80 e1
RSP: 0018:ffffc900006ef660 EFLAGS: 00000246
RAX: 0000000000000000 RBX: 1ffff11009608341 RCX: ffff8881006b8000
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc900006ef7e0 R08: ffffffff8fa3a837 R09: 1ffffffff1f47506
R10: dffffc0000000000 R11: fffffbfff1f47507 R12: ffff88804b041a08
R13: dffffc0000000000 R14: ffff88813663b1c0 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff8881a3c13000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 000000000df36000 CR4: 00000000000006f0
DR0: 0000200000000300 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 <TASK>
 on_each_cpu_cond_mask+0x3f/0x80
 smp_text_poke_batch_finish+0x5f9/0x1130
 arch_jump_label_transform_apply+0x1c/0x30
 static_key_enable_cpuslocked+0x128/0x250
 static_key_enable+0x1a/0x20
 toggle_allocation_gate+0xad/0x240
 process_scheduled_works+0xae1/0x17b0
 worker_thread+0x8a0/0xda0
 kthread+0x711/0x8a0
 ret_from_fork+0x439/0x7d0
 ret_from_fork_asm+0x1a/0x30
 </TASK>
