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BUG: KCSAN: data-race in tick_nohz_next_event / tick_sched_do_timer

write to 0xffffffff85cb3ad0 of 4 bytes by interrupt on cpu 1:
 tick_sched_do_timer+0xc0/0xe0 kernel/time/tick-sched.c:132
 tick_sched_timer+0x43/0xe0 kernel/time/tick-sched.c:1292
 __run_hrtimer kernel/time/hrtimer.c:1514 [inline]
 __hrtimer_run_queues+0x274/0x5f0 kernel/time/hrtimer.c:1576
 hrtimer_interrupt+0x22a/0x480 kernel/time/hrtimer.c:1638
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1110 [inline]
 smp_apic_timer_interrupt+0xdc/0x280 arch/x86/kernel/apic/apic.c:1135
 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:830
 arch_local_irq_enable arch/x86/include/asm/paravirt.h:766 [inline]
 preempt_schedule_irq+0x4d/0x90 kernel/sched/core.c:4327
 restore_regs_and_return_to_kernel+0x0/0x25
 arch_local_irq_restore arch/x86/include/asm/paravirt.h:756 [inline]
 kcsan_setup_watchpoint+0x1d4/0x460 kernel/kcsan/core.c:436
 check_access kernel/kcsan/core.c:466 [inline]
 __tsan_read4 kernel/kcsan/core.c:595 [inline]
 __tsan_read4+0xc6/0x100 kernel/kcsan/core.c:595
 __rcu_read_lock+0x2a/0x50 kernel/rcu/tree_plugin.h:358
 rcu_read_lock include/linux/rcupdate.h:597 [inline]
 batadv_nc_process_nc_paths.part.0+0x88/0x1d0 net/batman-adv/network-coding.c:686
 batadv_nc_process_nc_paths net/batman-adv/network-coding.c:678 [inline]
 batadv_nc_worker+0x359/0x390 net/batman-adv/network-coding.c:727
 process_one_work+0x3d4/0x890 kernel/workqueue.c:2269
 worker_thread+0xa0/0x800 kernel/workqueue.c:2415
 kthread+0x1d4/0x200 drivers/block/aoe/aoecmd.c:1253
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:352

read to 0xffffffff85cb3ad0 of 4 bytes by task 0 on cpu 0:
 tick_nohz_next_event+0x19d/0x370 kernel/time/tick-sched.c:725
 __tick_nohz_idle_stop_tick kernel/time/tick-sched.c:943 [inline]
 tick_nohz_idle_stop_tick+0x3c2/0x670 kernel/time/tick-sched.c:973
 cpuidle_idle_call kernel/sched/idle.c:151 [inline]
 do_idle+0x1a5/0x280 kernel/sched/idle.c:263
 cpu_startup_entry+0x1b/0x20 kernel/sched/idle.c:355
 rest_init+0xec/0xf6 init/main.c:452
 arch_call_rest_init+0x17/0x37
 start_kernel+0x838/0x85e init/main.c:786
 x86_64_start_reservations+0x29/0x2b arch/x86/kernel/head64.c:490
 x86_64_start_kernel+0x72/0x76 arch/x86/kernel/head64.c:471
 secondary_startup_64+0xa4/0xb0 arch/x86/kernel/head_64.S:241

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.4.0-rc7+ #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
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