rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	1-...!: (0 ticks this GP) idle=f03c/1/0x4000000000000000 softirq=136324/136324 fqs=6
rcu: 	(detected by 0, t=10502 jiffies, g=93929, q=108 ncpus=2)
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 29693 Comm: syz.2.6638 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:mm_get_cid+0xab/0x130
Code: 41 5c 41 5d 41 5e 41 5f 5d c3 cc cc cc cc cc 49 c7 c5 c8 54 c6 8d 49 c1 ed 03 bd 00 00 00 80 eb 07 44 89 f0 f7 d8 71 d4 f3 90 <43> 0f b6 44 25 00 84 c0 75 41 44 8b 3d 1c 6c 32 0c 48 89 df 4c 89
RSP: 0018:ffffc900035af968 EFLAGS: 00000887
RAX: 0000000080000000 RBX: ffff88810a003050 RCX: dffffc0000000000
RDX: 0000000000000002 RSI: 0000000000000002 RDI: ffff88810a003050
RBP: 0000000080000000 R08: ffff88810a002ed3 R09: 1ffff110214005da
R10: dffffc0000000000 R11: ffffed10214005db R12: dffffc0000000000
R13: 1ffffffff1b8ca99 R14: 0000000080000000 R15: 0000000000000002
FS:  000055557bc4c500(0000) GS:ffff8882a9a22000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f4ebe0706c0 CR3: 0000000115a2a000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 __schedule+0x222f/0x5060
 schedule+0x164/0x360
 do_nanosleep+0x1c2/0x620
 hrtimer_nanosleep+0x188/0x390
 __se_sys_clock_nanosleep+0x35b/0x3b0
 do_syscall_64+0xf0/0xf80
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f8bb3b5b58e
Code: Unable to access opcode bytes at 0x7f8bb3b5b564.
RSP: 002b:00007fffd5bf77a8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e6
RAX: ffffffffffffffda RBX: 000055557bc4c500 RCX: 00007f8bb3b5b58e
RDX: 00007fffd5bf7800 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007f8bb3e07da0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000000a34dc
R13: 00007f8bb3e0627c R14: 00000000000a3283 R15: 00007f8bb3e06270
 </TASK>
rcu: rcu_preempt kthread starved for 10490 jiffies! g93929 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=0
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:27104 pid:16    tgid:16    ppid:2      task_flags:0x208040 flags:0x00080000
Call Trace:
 <TASK>
 __schedule+0x1550/0x5060
 schedule+0x164/0x360
 schedule_timeout+0x158/0x2c0
 rcu_gp_fqs_loop+0x312/0x1560
 rcu_gp_kthread+0x9d/0x3b0
 kthread+0x726/0x8b0
 ret_from_fork+0x5b0/0xb20
 ret_from_fork_asm+0x1a/0x30
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
CPU: 0 UID: 0 PID: 15370 Comm: kworker/u9:41 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:__sanitizer_cov_trace_pc+0x5c/0x70
Code: 48 16 00 00 83 fa 02 75 21 48 8b 91 50 16 00 00 48 8b 32 48 8d 7e 01 8b 89 4c 16 00 00 48 39 cf 73 08 48 89 3a 48 89 44 f2 08 <e9> bf d1 b6 09 cc 66 66 66 66 66 2e 0f 1f 84 00 00 00 00 00 90 90
RSP: 0018:ffffc90004477618 EFLAGS: 00000293
RAX: ffffffff81b79a4f RBX: 1ffff110478c8129 RCX: ffff888115e1d7c0
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc900044777a0 R08: ffffffff8fc24f77 R09: 1ffffffff1f849ee
R10: dffffc0000000000 R11: fffffbfff1f849ef R12: ffff88823c640948
R13: dffffc0000000000 R14: ffff88812103bb00 R15: 0000000000000001
FS:  0000000000000000(0000) GS:ffff88818e422000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007efeadaf1d58 CR3: 000000000e13a000 CR4: 00000000000006f0
DR0: 0000200000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 <TASK>
 smp_call_function_many_cond+0xcff/0x12d0
 on_each_cpu_cond_mask+0x3f/0x80
 smp_text_poke_batch_finish+0x5f5/0x1160
 arch_jump_label_transform_apply+0x1c/0x30
 static_key_enable_cpuslocked+0x128/0x240
 static_key_enable+0x1a/0x20
 toggle_allocation_gate+0xab/0x250
 process_scheduled_works+0xaec/0x17a0
 worker_thread+0x89f/0xd90
 kthread+0x726/0x8b0
 ret_from_fork+0x5b0/0xb20
 ret_from_fork_asm+0x1a/0x30
 </TASK>
