rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 0-...!: (1 GPs behind) idle=56cc/0/0x1 softirq=100307/100308 fqs=0 rcu: (detected by 1, t=10505 jiffies, g=144461, q=36 ncpus=2) Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 0 Comm: swapper/0 Not tainted 6.4.0-rc7-syzkaller-00194-g8a28a0b6f1a1 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/27/2023 RIP: 0010:check_kcov_mode kernel/kcov.c:173 [inline] RIP: 0010:__sanitizer_cov_trace_pc+0x27/0x70 kernel/kcov.c:207 Code: 00 66 90 f3 0f 1e fa 65 8b 05 bd 4e 80 7e 89 c1 48 8b 34 24 81 e1 00 01 00 00 65 48 8b 14 25 00 ba 03 00 a9 00 01 ff 00 74 0e <85> c9 74 35 8b 82 0c 16 00 00 85 c0 74 2b 8b 82 e8 15 00 00 83 f8 RSP: 0018:ffffc90000007dc8 EFLAGS: 00000006 RAX: 0000000000010002 RBX: 0000000000000000 RCX: 0000000000000000 RDX: ffffffff8c495780 RSI: ffffffff8a020956 RDI: ffff888024865350 RBP: ffff888024865340 R08: 0000000000000006 R09: ffff888024865340 R10: ffff888024865340 R11: 0000000000000000 R12: ffff8880b982b840 R13: 0000000000000000 R14: ffff8880b982b840 R15: 0000000000000001 FS: 0000000000000000(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f831abdd718 CR3: 000000003006a000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: rb_insert_color_cached include/linux/rbtree.h:113 [inline] rb_add_cached include/linux/rbtree.h:183 [inline] timerqueue_add+0x256/0x330 lib/timerqueue.c:40 enqueue_hrtimer+0x171/0x320 kernel/time/hrtimer.c:1091 __run_hrtimer kernel/time/hrtimer.c:1702 [inline] __hrtimer_run_queues+0xa5b/0xbe0 kernel/time/hrtimer.c:1749 hrtimer_interrupt+0x320/0x7b0 kernel/time/hrtimer.c:1811 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1095 [inline] __sysvec_apic_timer_interrupt+0x14a/0x430 arch/x86/kernel/apic/apic.c:1112 sysvec_apic_timer_interrupt+0x92/0xc0 arch/x86/kernel/apic/apic.c:1106 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:645 RIP: 0010:native_irq_disable arch/x86/include/asm/irqflags.h:37 [inline] RIP: 0010:arch_local_irq_disable arch/x86/include/asm/irqflags.h:72 [inline] RIP: 0010:acpi_safe_halt+0x40/0x50 drivers/acpi/processor_idle.c:113 Code: eb 03 83 e3 01 89 de 0f 1f 44 00 00 84 db 75 1b 0f 1f 44 00 00 66 90 0f 1f 44 00 00 0f 00 2d c7 3b a2 00 0f 1f 44 00 00 fb f4 5b c3 cc 0f 1f 00 66 0f 1f 84 00 00 00 00 00 55 48 89 fd 53 0f RSP: 0018:ffffffff8c407d18 EFLAGS: 00000246 RAX: ffffffff8c495780 RBX: 0000000000000000 RCX: ffffffff8a0fb5e5 RDX: 0000000000000001 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffff888013eb5064 R08: 0000000000000001 R09: ffff8880b9836ceb R10: ffffed1017306d9d R11: 0000000000000000 R12: 0000000000000001 R13: ffff888013eb5000 R14: ffff888013eb5064 R15: 0000000000000000 acpi_idle_do_entry+0x53/0x70 drivers/acpi/processor_idle.c:573 acpi_idle_enter+0x173/0x290 drivers/acpi/processor_idle.c:711 cpuidle_enter_state+0xd3/0x6f0 drivers/cpuidle/cpuidle.c:267 cpuidle_enter+0x4e/0xa0 drivers/cpuidle/cpuidle.c:388 cpuidle_idle_call kernel/sched/idle.c:215 [inline] do_idle+0x2fe/0x3c0 kernel/sched/idle.c:282 cpu_startup_entry+0x18/0x20 kernel/sched/idle.c:379 rest_init+0x16f/0x2b0 init/main.c:735 arch_call_rest_init+0x13/0x30 init/main.c:834 start_kernel+0x3b6/0x490 init/main.c:1088 x86_64_start_reservations+0x18/0x30 arch/x86/kernel/head64.c:556 x86_64_start_kernel+0xb3/0xc0 arch/x86/kernel/head64.c:537 secondary_startup_64_no_verify+0xf4/0xfb rcu: rcu_preempt kthread timer wakeup didn't happen for 10504 jiffies! g144461 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 rcu: Possible timer handling issue on cpu=1 timer-softirq=107008 rcu: rcu_preempt kthread starved for 10505 jiffies! g144461 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->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:I stack:27736 pid:15 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5343 [inline] __schedule+0xc9a/0x5880 kernel/sched/core.c:6669 schedule+0xde/0x1a0 kernel/sched/core.c:6745 schedule_timeout+0x14e/0x2b0 kernel/time/timer.c:2167 rcu_gp_fqs_loop+0x190/0x910 kernel/rcu/tree.c:1609 rcu_gp_kthread+0x23a/0x360 kernel/rcu/tree.c:1808 kthread+0x344/0x440 kernel/kthread.c:379 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308 rcu: Stack dump where RCU GP kthread last ran: CPU: 1 PID: 5407 Comm: kworker/u4:9 Not tainted 6.4.0-rc7-syzkaller-00194-g8a28a0b6f1a1 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/27/2023 Workqueue: events_unbound toggle_allocation_gate RIP: 0010:csd_lock_wait kernel/smp.c:285 [inline] RIP: 0010:smp_call_function_many_cond+0x67f/0x15a0 kernel/smp.c:828 Code: 89 ee e8 d4 3f 0b 00 85 ed 74 48 48 8b 44 24 08 49 89 c4 83 e0 07 49 c1 ec 03 48 89 c5 4d 01 f4 83 c5 03 e8 93 43 0b 00 f3 90 <41> 0f b6 04 24 40 38 c5 7c 08 84 c0 0f 85 ad 0c 00 00 8b 43 08 31 RSP: 0018:ffffc90004a27948 EFLAGS: 00000293 RAX: 0000000000000000 RBX: ffffe8ffffc0b360 RCX: 0000000000000000 RDX: ffff88807a502180 RSI: ffffffff817827ad RDI: 0000000000000005 RBP: 0000000000000003 R08: 0000000000000005 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000001 R12: fffff91ffff8166d R13: 0000000000000000 R14: dffffc0000000000 R15: 0000000000000001 FS: 0000000000000000(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ffcea4a2df8 CR3: 000000000c571000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: on_each_cpu_cond_mask+0x5a/0xa0 kernel/smp.c:996 on_each_cpu include/linux/smp.h:71 [inline] text_poke_sync arch/x86/kernel/alternative.c:1770 [inline] text_poke_bp_batch+0x237/0x770 arch/x86/kernel/alternative.c:1970 text_poke_flush arch/x86/kernel/alternative.c:2161 [inline] text_poke_flush arch/x86/kernel/alternative.c:2158 [inline] text_poke_finish+0x1a/0x30 arch/x86/kernel/alternative.c:2168 arch_jump_label_transform_apply+0x17/0x30 arch/x86/kernel/jump_label.c:146 jump_label_update+0x32f/0x410 kernel/jump_label.c:829 static_key_enable_cpuslocked+0x1b5/0x270 kernel/jump_label.c:205 static_key_enable+0x1a/0x20 kernel/jump_label.c:218 toggle_allocation_gate mm/kfence/core.c:831 [inline] toggle_allocation_gate+0xf8/0x230 mm/kfence/core.c:823 process_one_work+0x99a/0x15e0 kernel/workqueue.c:2405 worker_thread+0x67d/0x10c0 kernel/workqueue.c:2552 kthread+0x344/0x440 kernel/kthread.c:379 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308