rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	0-....: (1 GPs behind) idle=aeec/1/0x4000000000000000 softirq=13449/13450 fqs=4767
rcu: 	         hardirqs   softirqs   csw/system
rcu: 	 number:  1333592          0            0
rcu: 	cputime:    31143      21355           74   ==> 52510(ms)
rcu: 	(t=10502 jiffies g=9821 q=3923 ncpus=2)
CPU: 0 UID: 0 PID: 6184 Comm: syz.0.91 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:lock_acquire+0x20b/0x2e0
Code: e9 30 ff ff ff e8 d5 d2 ed 09 f7 c3 00 02 00 00 0f 84 38 ff ff ff 65 48 8b 05 51 50 57 11 48 3b 44 24 30 75 33 fb 48 83 c4 38 <5b> 41 5c 41 5d 41 5e 41 5f 5d c3 cc cc cc cc cc 48 8d 3d 2e c0 53
RSP: 0018:ffffc90000007c60 EFLAGS: 00000296
RAX: 90c76c47c99ed600 RBX: 0000000000000246 RCX: 0000000000000101
RDX: 00000000b1ae6500 RSI: ffffffff8df5fbe0 RDI: ffffffff8c076d00
RBP: 0000000000000000 R08: ffffffff81b09e04 R09: ffffc90000007ce0
R10: ffffc90000007ce8 R11: fffff52000000f9f R12: 0000000000000000
R13: ffffc90000007ce0 R14: 0000000000000000 R15: 0000000000000001
FS:  00007ff29da776c0(0000) GS:ffff88818e0a4000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00002000001a1000 CR3: 0000000116b30000 CR4: 00000000000006f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 <IRQ>
 call_timer_fn+0xf1/0x640
 __run_timer_base+0x652/0x8b0
 run_timer_softirq+0xb7/0x170
 handle_softirqs+0x22a/0x870
 __irq_exit_rcu+0x5f/0x150
 irq_exit_rcu+0x9/0x30
 sysvec_apic_timer_interrupt+0xa6/0xc0
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20
RIP: 0010:finish_task_switch+0x245/0x920
Code: 00 00 48 85 db 0f 85 e8 01 00 00 0f 1f 44 00 00 4c 8b 75 d0 49 83 c4 48 4c 89 e7 e8 85 ca fc 09 e8 20 85 37 00 fb 4c 8b 65 c0 <49> 8d bc 24 30 16 00 00 48 89 f8 48 c1 e8 03 42 0f b6 04 28 84 c0
RSP: 0018:ffffc9000839f3b8 EFLAGS: 00000202
RAX: 00000000000026e9 RBX: 0000000000000000 RCX: 0000000080000001
RDX: 0000000000000006 RSI: ffffffff8dcf1f4e RDI: ffffffff8c076d00
RBP: ffffc9000839f410 R08: ffffffff8ff0e0b7 R09: 1ffffffff1fe1c16
R10: dffffc0000000000 R11: fffffbfff1fe1c17 R12: ffff88801d0e0000
R13: dffffc0000000000 R14: ffff88801d8e0000 R15: ffff88812103b918
 __schedule+0x1546/0x5070
 preempt_schedule_irq+0x4d/0xa0
 irqentry_exit+0x599/0x620
 asm_sysvec_apic_timer_interrupt+0x1a/0x20
RIP: 0010:rep_movs_alternative+0x75/0x90
Code: 05 e9 ff 42 04 00 48 8b 06 48 89 07 48 8d 47 08 48 83 e0 f8 48 29 f8 48 01 c7 48 01 c6 48 29 c1 48 89 c8 48 c1 e9 03 83 e0 07 <f3> 48 a5 89 c1 85 c9 75 91 e9 cd 42 04 00 48 8d 0c c8 eb 86 cc cc
RSP: 0018:ffffc9000839f758 EFLAGS: 00010246
RAX: 0000000000000000 RBX: ffff88801db78000 RCX: 0000000000000e28
RDX: 0000000000000001 RSI: 00002000001a1000 RDI: ffff88801db78ec0
RBP: ffffc9000839f8b0 R08: ffff88801db7ffff R09: 1ffff11003b6ffff
R10: dffffc0000000000 R11: ffffed1003b70000 R12: ffffc9000839fbb8
R13: 00002000001a0140 R14: 0000000000008000 R15: 1ffff92001073f77
 _copy_from_iter+0x21b/0x1670
 kcm_sendmsg+0xf0d/0x2b00
 sock_sendmsg_nosec+0x18f/0x1d0
 sock_write_iter+0x302/0x410
 vfs_write+0x61d/0xb90
 ksys_write+0x150/0x270
 do_syscall_64+0x14d/0xf80
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7ff29cb9acb9
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ff29da77028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007ff29ce15fa0 RCX: 00007ff29cb9acb9
RDX: 00000000fffffdef RSI: 0000200000000140 RDI: 0000000000000009
RBP: 00007ff29cc08bf7 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ff29ce16038 R14: 00007ff29ce15fa0 R15: 00007fff1c8121b8
 </TASK>
sched: DL replenish lagged too much
