rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	0-...!: (1 GPs behind) idle=a1ac/1/0x4000000000000000 softirq=55356/55361 fqs=0
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P14234/1:b..l
rcu: 	(detected by 1, t=10505 jiffies, g=48685, q=81 ncpus=2)
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 14236 Comm: syz.3.2528 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:mark_lock+0x2f/0x190
Code: 41 55 41 54 53 8b 46 20 89 c1 81 e1 00 00 03 00 83 f9 01 bb 09 00 00 00 83 db 00 83 fa 08 0f 45 da bd 01 00 00 00 89 d9 d3 e5 <25> ff 1f 00 00 48 0f a3 05 04 f4 0a 12 73 10 48 69 c0 c8 00 00 00
RSP: 0018:ffffc90000007718 EFLAGS: 00000093
RAX: 00000000000c4067 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffff88810d8c61a8 RDI: ffff88810d8c5640
RBP: 0000000000000001 R08: 0000000000000000 R09: ffffffff81ada78b
R10: ffffc90000007448 R11: fffff52000000e8b R12: 0000000000000002
R13: 0000000000000002 R14: ffff88810d8c61a8 R15: 0000000000000000
FS:  00007f3c00bfb6c0(0000) GS:ffff8880b8613000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b3360dff8 CR3: 0000000035494000 CR4: 00000000000006f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000082
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 <IRQ>
 __lock_acquire+0x65a/0xd20
 lock_acquire+0x120/0x360
 _raw_spin_lock_irqsave+0xa7/0xf0
 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:preempt_schedule_irq+0xb0/0x150
Code: 24 20 f6 44 24 21 02 74 0c 90 0f 0b 48 f7 03 08 00 00 00 74 64 bf 01 00 00 00 e8 ab 8a 14 f6 e8 16 e7 4b f6 fb bf 01 00 00 00 <e8> 5b ab ff ff 48 c7 44 24 40 00 00 00 00 9c 8f 44 24 40 8b 44 24
RSP: 0018:ffffc90003e87900 EFLAGS: 00000286
RAX: 3b3b4646085c2b00 RBX: 0000000000000000 RCX: 3b3b4646085c2b00
RDX: 0000000000000006 RSI: ffffffff8d9ba160 RDI: 0000000000000001
RBP: ffffc90003e879b0 R08: ffffffff8fa3a837 R09: 1ffffffff1f47506
R10: dffffc0000000000 R11: fffffbfff1f47507 R12: 0000000000000000
R13: 0000000000000000 R14: dffffc0000000000 R15: 1ffff920007d0f20
 irqentry_exit+0x6f/0x90
 asm_sysvec_call_function_single+0x1a/0x20
RIP: 0010:perf_trace_init+0x96/0x2d0
Code: 5a 00 48 8b 1d db 9f 50 0c 48 81 fb 20 d7 19 8e 0f 84 75 01 00 00 4c 89 24 24 4c 8d 63 30 4c 89 e0 48 c1 e8 03 42 0f b6 04 30 <84> c0 0f 85 17 01 00 00 4d 63 24 24 4c 89 ff 4c 89 e6 e8 e3 8b f6
RSP: 0018:ffffc90003e87a78 EFLAGS: 00000a06
RAX: 0000000000000000 RBX: ffffffff8f6fa5c0 RCX: 0000000000080000
RDX: ffffc90028287000 RSI: 0000000000000817 RDI: 0000000000000818
RBP: 0000000000000002 R08: ffffffff8fa3a837 R09: 1ffffffff1f47506
R10: dffffc0000000000 R11: fffffbfff1f47507 R12: ffffffff8f6fa5f0
R13: 0000000000000000 R14: dffffc0000000000 R15: 00000000000000df
 perf_tp_event_init+0x8d/0x120
 perf_try_init_event+0x17f/0x870
 perf_event_alloc+0x133e/0x2be0
 __se_sys_perf_event_open+0x772/0x1d70
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f3bffd8eba9
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:00007f3c00bfb038 EFLAGS: 00000246 ORIG_RAX: 000000000000012a
RAX: ffffffffffffffda RBX: 00007f3bfffd5fa0 RCX: 00007f3bffd8eba9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00002000000002c0
RBP: 00007f3bffe11e19 R08: 0000000000000000 R09: 0000000000000000
R10: ffffffffffffffff R11: 0000000000000246 R12: 0000000000000000
R13: 00007f3bfffd6038 R14: 00007f3bfffd5fa0 R15: 00007fff48fa4ff8
 </TASK>
task:syz.3.2527      state:R  running task     stack:21520 pid:14234 tgid:14234 ppid:9320   task_flags:0x400640 flags:0x00004002
Call Trace:
 <TASK>
 __schedule+0x1798/0x4cc0
 preempt_schedule_notrace+0xd1/0x110
 preempt_schedule_notrace_thunk+0x16/0x30
 lock_acquire+0x347/0x360
 ___pte_offset_map+0x45/0x250
 pte_offset_map_rw_nolock+0x3b/0x160
 __handle_mm_fault+0xb3a/0x5440
 handle_mm_fault+0x40a/0x8e0
 __get_user_pages+0x1699/0x2ce0
 get_dump_page+0x1ac/0x3f0
 dump_user_range+0x1de/0xc90
 elf_core_dump+0x337b/0x3990
 coredump_write+0x1169/0x1900
 vfs_coredump+0x1daa/0x2a50
 get_signal+0x1109/0x1340
 arch_do_signal_or_restart+0x9a/0x750
 irqentry_exit_to_user_mode+0x81/0x120
 exc_page_fault+0x9f/0xf0
 asm_exc_page_fault+0x26/0x30
RIP: 0033:0x7f3bffc4f927
RSP: 002b:00007f3c00bdc0e0 EFLAGS: 00010202
RAX: 0000000000000000 RBX: 000000000000000b RCX: 00007f3bffd8eba9
RDX: 00007f3c00bdc100 RSI: 00007f3c00bdc230 RDI: 000000000000000b
RBP: 00007f3bffe11e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000
R13: 00007f3bfffd6038 R14: 00007f3bfffd5fa0 R15: 00007fff48fa4ff8
 </TASK>
rcu: rcu_preempt kthread starved for 10505 jiffies! g48685 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:26664 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: 14222 Comm: syz.4.2525 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:smp_call_function_many_cond+0xd33/0x12d0
Code: 45 8b 2c 24 44 89 ee 83 e6 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
RSP: 0018:ffffc90003f4f340 EFLAGS: 00000293
RAX: ffffffff81b4621b RBX: 1ffff11009608341 RCX: ffff88801fff9cc0
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc90003f4f4c0 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: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 <TASK>
 on_each_cpu_cond_mask+0x3f/0x80
 flush_tlb_mm_range+0x6b1/0x12d0
 tlb_flush_mmu+0x1a7/0x680
 tlb_finish_mmu+0xc3/0x1d0
 free_ldt_pgtables+0x17b/0x320
 exit_mmap+0x17c/0xb50
 __mmput+0x118/0x430
 exit_mm+0x1da/0x2c0
 do_exit+0x648/0x2300
 do_group_exit+0x21c/0x2d0
 get_signal+0x1286/0x1340
 arch_do_signal_or_restart+0x9a/0x750
 exit_to_user_mode_loop+0x75/0x110
 do_syscall_64+0x2bd/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f9c6b58eba9
Code: Unable to access opcode bytes at 0x7f9c6b58eb7f.
RSP: 002b:00007f9c6c4b5038 EFLAGS: 00000246 ORIG_RAX: 000000000000002f
RAX: fffffffffffffe00 RBX: 00007f9c6b7d5fa0 RCX: 00007f9c6b58eba9
RDX: 0000000000000000 RSI: 0000200000000400 RDI: 0000000000000005
RBP: 00007f9c6b611e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f9c6b7d6038 R14: 00007f9c6b7d5fa0 R15: 00007ffc9ea37b58
 </TASK>
