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BUG: KCSAN: data-race in timer_clear_idle / trigger_dyntick_cpu.isra.0

write to 0xffff88812c11dca4 of 1 bytes by task 0 on cpu 1:
 timer_clear_idle+0x3d/0x50 kernel/time/timer.c:1676
 tick_nohz_restart_sched_tick kernel/time/tick-sched.c:860 [inline]
 __tick_nohz_idle_restart_tick+0x32/0x1a0 kernel/time/tick-sched.c:1161
 tick_nohz_idle_exit+0x19c/0x1d0 kernel/time/tick-sched.c:1202
 do_idle+0xac/0x290 kernel/sched/idle.c:282
 cpu_startup_entry+0x14/0x20 kernel/sched/idle.c:361
 start_secondary+0x169/0x1b0 arch/x86/kernel/smpboot.c:268
 secondary_startup_64+0xa4/0xb0 arch/x86/kernel/head_64.S:242

read to 0xffff88812c11dca4 of 1 bytes by interrupt on cpu 0:
 trigger_dyntick_cpu.isra.0+0x6d/0xf0 kernel/time/timer.c:577
 internal_add_timer kernel/time/timer.c:596 [inline]
 add_timer_on+0x192/0x2c0 kernel/time/timer.c:1175
 clocksource_watchdog+0x699/0x7c0 kernel/time/clocksource.c:303
 call_timer_fn+0x58/0x2e0 kernel/time/timer.c:1405
 expire_timers kernel/time/timer.c:1450 [inline]
 __run_timers kernel/time/timer.c:1774 [inline]
 __run_timers kernel/time/timer.c:1741 [inline]
 run_timer_softirq+0xb14/0xbd0 kernel/time/timer.c:1787
 __do_softirq+0x118/0x34a kernel/softirq.c:292
 invoke_softirq kernel/softirq.c:373 [inline]
 irq_exit+0xb5/0xd0 kernel/softirq.c:413
 exiting_irq arch/x86/include/asm/apic.h:546 [inline]
 smp_apic_timer_interrupt+0xe2/0x270 arch/x86/kernel/apic/apic.c:1140
 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:829
 arch_local_irq_restore arch/x86/include/asm/paravirt.h:759 [inline]
 kcsan_setup_watchpoint+0x25a/0x440 kernel/kcsan/core.c:542
 wait_consider_task+0x216/0x1c60 kernel/exit.c:1279
 do_wait_thread kernel/exit.c:1368 [inline]
 do_wait+0x1c7/0x4c0 kernel/exit.c:1439
 kernel_wait4+0x146/0x230 kernel/exit.c:1611
 __do_sys_wait4+0xea/0x100 kernel/exit.c:1623
 __se_sys_wait4 kernel/exit.c:1619 [inline]
 __x64_sys_wait4+0x59/0x70 kernel/exit.c:1619
 do_syscall_64+0xc7/0x3b0 arch/x86/entry/common.c:295
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 6881 Comm: syz-executor.1 Not tainted 5.7.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
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